Struct Almanac
pub struct Almanac {
pub spk_data: IndexMap<String, DAF<SPKSummaryRecord>>,
pub bpc_data: IndexMap<String, DAF<BPCSummaryRecord>>,
pub planetary_data: IndexMap<String, DataSet<PlanetaryData>>,
pub spacecraft_data: IndexMap<String, DataSet<SpacecraftData>>,
pub euler_param_data: IndexMap<String, DataSet<EulerParameter>>,
pub location_data: IndexMap<String, DataSet<Location>>,
pub instrument_data: IndexMap<String, DataSet<Instrument>>,
}Expand description
An Almanac contains all of the loaded SPICE and ANISE data. It is the context for all computations.
:type path: str :rtype: Almanac
Fields§
§spk_data: IndexMap<String, DAF<SPKSummaryRecord>>NAIF SPK is kept unchanged
bpc_data: IndexMap<String, DAF<BPCSummaryRecord>>NAIF BPC is kept unchanged
planetary_data: IndexMap<String, DataSet<PlanetaryData>>Dataset of planetary data
spacecraft_data: IndexMap<String, DataSet<SpacecraftData>>Dataset of spacecraft data
euler_param_data: IndexMap<String, DataSet<EulerParameter>>Dataset of euler parameters
location_data: IndexMap<String, DataSet<Location>>Dataset of locations
instrument_data: IndexMap<String, DataSet<Instrument>>Dataset of instruments
Implementations§
§impl Almanac
impl Almanac
pub fn location_from_id(&self, id: i32) -> Result<Location, AlmanacError>
pub fn location_from_id(&self, id: i32) -> Result<Location, AlmanacError>
Returns the Location from its ID, searching through all loaded location datasets in reverse order.
pub fn location_from_name(&self, name: &str) -> Result<Location, AlmanacError>
pub fn location_from_name(&self, name: &str) -> Result<Location, AlmanacError>
Returns the Location from its name, searching through all loaded location datasets in reverse order.
pub fn azimuth_elevation_range_sez(
&self,
rx: CartesianState,
tx: CartesianState,
obstructing_body: Option<Frame>,
ab_corr: Option<Aberration>,
) -> Result<AzElRange, AlmanacError>
pub fn azimuth_elevation_range_sez( &self, rx: CartesianState, tx: CartesianState, obstructing_body: Option<Frame>, ab_corr: Option<Aberration>, ) -> Result<AzElRange, AlmanacError>
Computes the azimuth (in degrees), elevation (in degrees), and range (in kilometers) of the
receiver state (rx) seen from the transmitter state (tx), once converted into the SEZ frame of the transmitter.
§Warning
The obstructing body should be a tri-axial ellipsoid body, e.g. IAU_MOON_FRAME.
§Algorithm
- If any obstructing_bodies are provided, ensure that none of these are obstructing the line of sight between the receiver and transmitter.
- Compute the SEZ (South East Zenith) frame of the transmitter.
- Rotate the receiver position vector into the transmitter SEZ frame.
- Rotate the transmitter position vector into that same SEZ frame.
- Compute the range as the norm of the difference between these two position vectors.
- Compute the elevation, and ensure it is between +/- 180 degrees.
- Compute the azimuth with a quadrant check, and ensure it is between 0 and 360 degrees.
Examples found in repository?
30fn main() -> Result<(), Box<dyn Error>> {
31 pel::init();
32 // Dynamics models require planetary constants and ephemerides to be defined.
33 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
34 // This will automatically download the DE440s planetary ephemeris,
35 // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
36 // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
37 // planetary constants kernels.
38 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
39 // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
40 // references to many functions.
41 let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
42 // Define the orbit epoch
43 let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
44
45 // Define the orbit.
46 // First we need to fetch the Earth J2000 from information from the Almanac.
47 // This allows the frame to include the gravitational parameters and the shape of the Earth,
48 // defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
49 // by loading a different set of planetary constants.
50 let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
51
52 let orbit =
53 Orbit::try_keplerian_altitude(300.0, 0.015, 68.5, 65.2, 75.0, 0.0, epoch, earth_j2000)?;
54 // Print in in Keplerian form.
55 println!("{orbit:x}");
56
57 // There are two ways to propagate an orbit. We can make a quick approximation assuming only two-body
58 // motion. This is a useful first order approximation but it isn't used in real-world applications.
59
60 // This approach is a feature of ANISE.
61 let future_orbit_tb = orbit.at_epoch(epoch + Unit::Day * 3)?;
62 println!("{future_orbit_tb:x}");
63
64 // Two body propagation relies solely on Kepler's laws, so only the true anomaly will change.
65 println!(
66 "SMA changed by {:.3e} km",
67 orbit.sma_km()? - future_orbit_tb.sma_km()?
68 );
69 println!(
70 "ECC changed by {:.3e}",
71 orbit.ecc()? - future_orbit_tb.ecc()?
72 );
73 println!(
74 "INC changed by {:.3e} deg",
75 orbit.inc_deg()? - future_orbit_tb.inc_deg()?
76 );
77 println!(
78 "RAAN changed by {:.3e} deg",
79 orbit.raan_deg()? - future_orbit_tb.raan_deg()?
80 );
81 println!(
82 "AOP changed by {:.3e} deg",
83 orbit.aop_deg()? - future_orbit_tb.aop_deg()?
84 );
85 println!(
86 "TA changed by {:.3} deg",
87 orbit.ta_deg()? - future_orbit_tb.ta_deg()?
88 );
89
90 // Nyx is used for high fidelity propagation, not Keplerian propagation as above.
91 // Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
92 // models such as solar radiation pressure.
93
94 // Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
95 let sc = Spacecraft::builder()
96 .orbit(orbit)
97 .mass(Mass::from_dry_mass(9.60))
98 .srp(SRPData {
99 area_m2: 10e-4,
100 coeff_reflectivity: 1.1,
101 })
102 .build();
103 println!("{sc:x}");
104
105 // Set up the spacecraft dynamics.
106
107 // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
108 // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
109 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
110
111 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
112 // We're using the JGM3 model here, which is the default in GMAT.
113 let mut jgm3_meta = MetaFile {
114 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
115 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
116 };
117 // And let's download it if we don't have it yet.
118 jgm3_meta.process(true)?;
119
120 // Build the spherical harmonics.
121 // The harmonics must be computed in the body fixed frame.
122 // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
123 let harmonics_21x21 = Harmonics::from_stor(
124 almanac.frame_info(IAU_EARTH_FRAME)?,
125 HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
126 );
127
128 // Include the spherical harmonics into the orbital dynamics.
129 orbital_dyn.accel_models.push(harmonics_21x21);
130
131 // We define the solar radiation pressure, using the default solar flux and accounting only
132 // for the eclipsing caused by the Earth.
133 let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
134
135 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
136 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
137 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
138
139 println!("{dynamics}");
140
141 // Finally, let's propagate this orbit to the same epoch as above.
142 // The first returned value is the spacecraft state at the final epoch.
143 // The second value is the full trajectory where the step size is variable step used by the propagator.
144 let (future_sc, trajectory) = Propagator::default(dynamics)
145 .with(sc, almanac.clone())
146 .until_epoch_with_traj(future_orbit_tb.epoch)?;
147
148 println!("=== High fidelity propagation ===");
149 println!(
150 "SMA changed by {:.3} km",
151 orbit.sma_km()? - future_sc.orbit.sma_km()?
152 );
153 println!(
154 "ECC changed by {:.6}",
155 orbit.ecc()? - future_sc.orbit.ecc()?
156 );
157 println!(
158 "INC changed by {:.3e} deg",
159 orbit.inc_deg()? - future_sc.orbit.inc_deg()?
160 );
161 println!(
162 "RAAN changed by {:.3} deg",
163 orbit.raan_deg()? - future_sc.orbit.raan_deg()?
164 );
165 println!(
166 "AOP changed by {:.3} deg",
167 orbit.aop_deg()? - future_sc.orbit.aop_deg()?
168 );
169 println!(
170 "TA changed by {:.3} deg",
171 orbit.ta_deg()? - future_sc.orbit.ta_deg()?
172 );
173
174 // We also have access to the full trajectory throughout the propagation.
175 println!("{trajectory}");
176
177 // With the trajectory, let's build a few data products.
178
179 // 1. Export the trajectory as a CCSDS OEM version 2.0 file and as a parquet file, which includes the Keplerian orbital elements.
180
181 trajectory.to_oem_file(
182 "./01_cubesat_hf_prop.oem",
183 ExportCfg::builder().step(Unit::Minute * 2).build(),
184 )?;
185
186 trajectory.to_parquet_with_cfg(
187 "./01_cubesat_hf_prop.parquet",
188 ExportCfg::builder().step(Unit::Minute * 2).build(),
189 )?;
190
191 // 2. Compare the difference in the radial-intrack-crosstrack frame between the high fidelity
192 // and Keplerian propagation. The RIC frame is commonly used to compute the difference in position
193 // and velocity of different spacecraft.
194 // 3. Compute the azimuth, elevation, range, and range-rate data of that spacecraft as seen from Boulder, CO, USA.
195
196 let boulder_station = GroundStation::from_point(
197 "Boulder, CO, USA".to_string(),
198 40.014984, // latitude in degrees
199 -105.270546, // longitude in degrees
200 1.6550, // altitude in kilometers
201 almanac.frame_info(IAU_EARTH_FRAME)?,
202 );
203
204 // We iterate over the trajectory, grabbing a state every two minutes.
205 let mut offset_s = vec![];
206 let mut epoch_str = vec![];
207 let mut ric_x_km = vec![];
208 let mut ric_y_km = vec![];
209 let mut ric_z_km = vec![];
210 let mut ric_vx_km_s = vec![];
211 let mut ric_vy_km_s = vec![];
212 let mut ric_vz_km_s = vec![];
213
214 let mut azimuth_deg = vec![];
215 let mut elevation_deg = vec![];
216 let mut range_km = vec![];
217 let mut range_rate_km_s = vec![];
218 for state in trajectory.every(Unit::Minute * 2) {
219 // Try to compute the Keplerian/two body state just in time.
220 // This method occasionally fails to converge on an appropriate true anomaly
221 // from the mean anomaly. If that happens, we just skip this state.
222 // The high fidelity and Keplerian states diverge continuously, and we're curious
223 // about the divergence in this quick analysis.
224 let this_epoch = state.epoch();
225 match orbit.at_epoch(this_epoch) {
226 Ok(tb_then) => {
227 offset_s.push((this_epoch - orbit.epoch).to_seconds());
228 epoch_str.push(format!("{this_epoch}"));
229 // Compute the two body state just in time.
230 let ric = state.orbit.ric_difference(&tb_then)?;
231 ric_x_km.push(ric.radius_km.x);
232 ric_y_km.push(ric.radius_km.y);
233 ric_z_km.push(ric.radius_km.z);
234 ric_vx_km_s.push(ric.velocity_km_s.x);
235 ric_vy_km_s.push(ric.velocity_km_s.y);
236 ric_vz_km_s.push(ric.velocity_km_s.z);
237
238 // Compute the AER data for each state.
239 let aer = almanac.azimuth_elevation_range_sez(
240 state.orbit,
241 boulder_station.to_orbit(this_epoch, &almanac)?,
242 None,
243 None,
244 )?;
245 azimuth_deg.push(aer.azimuth_deg);
246 elevation_deg.push(aer.elevation_deg);
247 range_km.push(aer.range_km);
248 range_rate_km_s.push(aer.range_rate_km_s);
249 }
250 Err(e) => warn!("{} {e}", state.epoch()),
251 };
252 }
253
254 // Build the data frames.
255 let ric_df = df!(
256 "Offset (s)" => offset_s.clone(),
257 "Epoch" => epoch_str.clone(),
258 "RIC X (km)" => ric_x_km,
259 "RIC Y (km)" => ric_y_km,
260 "RIC Z (km)" => ric_z_km,
261 "RIC VX (km/s)" => ric_vx_km_s,
262 "RIC VY (km/s)" => ric_vy_km_s,
263 "RIC VZ (km/s)" => ric_vz_km_s,
264 )?;
265
266 println!("RIC difference at start\n{}", ric_df.head(Some(10)));
267 println!("RIC difference at end\n{}", ric_df.tail(Some(10)));
268
269 let aer_df = df!(
270 "Offset (s)" => offset_s.clone(),
271 "Epoch" => epoch_str.clone(),
272 "azimuth (deg)" => azimuth_deg,
273 "elevation (deg)" => elevation_deg,
274 "range (km)" => range_km,
275 "range rate (km/s)" => range_rate_km_s,
276 )?;
277
278 // Finally, let's see when the spacecraft is visible, assuming 15 degrees minimum elevation.
279 let mask = aer_df
280 .column("elevation (deg)")?
281 .gt(&Column::Scalar(ScalarColumn::new(
282 "elevation mask (deg)".into(),
283 Scalar::new(DataType::Float64, AnyValue::Float64(15.0)),
284 offset_s.len(),
285 )))?;
286 let cubesat_visible = aer_df.filter(&mask)?;
287
288 println!("{cubesat_visible}");
289
290 Ok(())
291}pub fn azimuth_elevation_range_sez_from_location_id(
&self,
rx: CartesianState,
location_id: i32,
obstructing_body: Option<Frame>,
ab_corr: Option<Aberration>,
) -> Result<AzElRange, AlmanacError>
pub fn azimuth_elevation_range_sez_from_location_id( &self, rx: CartesianState, location_id: i32, obstructing_body: Option<Frame>, ab_corr: Option<Aberration>, ) -> Result<AzElRange, AlmanacError>
Computes the azimuth (in degrees), elevation (in degrees), and range (in kilometers) of the
receiver state (rx) seen from the location ID (as transmitter state, once converted into the SEZ frame of the transmitter.
Refer to [azimuth_elevation_range_sez] for algorithm details.
pub fn azimuth_elevation_range_sez_from_location_name(
&self,
rx: CartesianState,
location_name: &str,
obstructing_body: Option<Frame>,
ab_corr: Option<Aberration>,
) -> Result<AzElRange, AlmanacError>
pub fn azimuth_elevation_range_sez_from_location_name( &self, rx: CartesianState, location_name: &str, obstructing_body: Option<Frame>, ab_corr: Option<Aberration>, ) -> Result<AzElRange, AlmanacError>
Computes the azimuth (in degrees), elevation (in degrees), and range (in kilometers) of the
receiver state (rx) seen from the location ID (as transmitter state, once converted into the SEZ frame of the transmitter.
Refer to [azimuth_elevation_range_sez] for algorithm details.
pub fn azimuth_elevation_range_sez_from_location(
&self,
rx: CartesianState,
location: Location,
obstructing_body: Option<Frame>,
ab_corr: Option<Aberration>,
) -> Result<AzElRange, AlmanacError>
pub fn azimuth_elevation_range_sez_from_location( &self, rx: CartesianState, location: Location, obstructing_body: Option<Frame>, ab_corr: Option<Aberration>, ) -> Result<AzElRange, AlmanacError>
Computes the azimuth (in degrees), elevation (in degrees), range (in kilometers), and range-rate (in km/s) of the
receiver state (rx) seen from the provided location (as transmitter state, once converted into the SEZ frame of the transmitter.
Refer to [azimuth_elevation_range_sez] for algorithm details.
Location terrain masks are always applied, i.e. if the terrain masks the object, unless specified otherwise in the Location.
Use the elevation_above_mask_deg() method to check if the object is obstructed by the terrain.
§impl Almanac
impl Almanac
pub fn from_bpc(bpc: DAF<BPCSummaryRecord>) -> Almanac
pub fn with_bpc(self, bpc: DAF<BPCSummaryRecord>) -> Almanac
pub fn with_bpc(self, bpc: DAF<BPCSummaryRecord>) -> Almanac
Loads a new Binary Planetary Constants (BPC) kernel into a new context, using the system time as the alias. If the time is not availble, then 0 TAI is used. This new context is needed to satisfy the unloading of files. In fact, to unload a file, simply let the newly loaded context drop out of scope and Rust will clean it up.
pub fn with_bpc_as(
self,
bpc: DAF<BPCSummaryRecord>,
alias: Option<String>,
) -> Almanac
pub fn with_bpc_as( self, bpc: DAF<BPCSummaryRecord>, alias: Option<String>, ) -> Almanac
Loads a new Binary Planetary Constant (BPC) file into a new context, naming it with the provided alias or the current system time. To unload a file, call bpc_unload.
pub fn bpc_unload(&mut self, alias: &str) -> Result<(), OrientationError>
pub fn bpc_unload(&mut self, alias: &str) -> Result<(), OrientationError>
Unloads the BPC with the provided alias. WARNING: This causes the order of the loaded files to be perturbed, which may be an issue if several SPKs with the same IDs are loaded.
pub fn num_loaded_bpc(&self) -> usize
pub fn bpc_summary_from_name_at_epoch(
&self,
name: &str,
epoch: Epoch,
) -> Result<(&BPCSummaryRecord, usize, Option<usize>, usize), OrientationError>
pub fn bpc_summary_from_name_at_epoch( &self, name: &str, epoch: Epoch, ) -> Result<(&BPCSummaryRecord, usize, Option<usize>, usize), OrientationError>
Returns the summary given the name of the summary record if that summary has data defined at the requested epoch and the BPC where this name was found to be valid at that epoch.
pub fn bpc_summary_at_epoch(
&self,
id: i32,
epoch: Epoch,
) -> Result<(&BPCSummaryRecord, usize, Option<usize>, usize), OrientationError>
pub fn bpc_summary_at_epoch( &self, id: i32, epoch: Epoch, ) -> Result<(&BPCSummaryRecord, usize, Option<usize>, usize), OrientationError>
Returns the summary given the name of the summary record if that summary has data defined at the requested epoch
§impl Almanac
impl Almanac
pub fn bpc_summaries(
&self,
id: i32,
) -> Result<Vec<BPCSummaryRecord>, OrientationError>
pub fn bpc_summaries( &self, id: i32, ) -> Result<Vec<BPCSummaryRecord>, OrientationError>
Returns a vector of the summaries whose ID matches the desired id, in the order in which they will be used, i.e. in reverse loading order.
§Warning
This function performs a memory allocation.
:type id: int :rtype: typing.List
pub fn bpc_domain(&self, id: i32) -> Result<(Epoch, Epoch), OrientationError>
pub fn bpc_domain(&self, id: i32) -> Result<(Epoch, Epoch), OrientationError>
Returns the applicable domain of the request id, i.e. start and end epoch that the provided id has loaded data.
:type id: int :rtype: typing.Tuple
§impl Almanac
impl Almanac
pub fn line_of_sight_obstructed(
&self,
observer: CartesianState,
observed: CartesianState,
obstructing_body: Frame,
ab_corr: Option<Aberration>,
) -> Result<bool, AlmanacError>
pub fn line_of_sight_obstructed( &self, observer: CartesianState, observed: CartesianState, obstructing_body: Frame, ab_corr: Option<Aberration>, ) -> Result<bool, AlmanacError>
Computes whether the line of sight between an observer and an observed Cartesian state is obstructed by the obstructing body. Returns true if the obstructing body is in the way, false otherwise.
For example, if the Moon is in between a Lunar orbiter (observed) and a ground station (observer), then this function returns true
because the Moon (obstructing body) is indeed obstructing the line of sight.
Observed
o -
+ -
+ -
+ *** -
* + * -
* + + * + + o
* * Observer
****Key Elements:
orepresents the positions of the observer and observed objects.- The dashed line connecting the observer and observed is the line of sight.
Algorithm (source: Algorithm 35 of Vallado, 4th edition, page 308.):
r1andr2are the transformed radii of the observed and observer objects, respectively.r1sqandr2sqare the squared magnitudes of these vectors.r1dotr2is the dot product ofr1andr2.tauis a parameter that determines the intersection point along the line of sight.- The condition
(1.0 - tau) * r1sq + r1dotr2 * tau <= ob_mean_eq_radius_km^2checks if the line of sight is within the obstructing body’s radius, indicating an obstruction.
pub fn occultation(
&self,
back_frame: Frame,
front_frame: Frame,
observer: CartesianState,
ab_corr: Option<Aberration>,
) -> Result<Occultation, AlmanacError>
pub fn occultation( &self, back_frame: Frame, front_frame: Frame, observer: CartesianState, ab_corr: Option<Aberration>, ) -> Result<Occultation, AlmanacError>
Computes the occultation percentage of the back_frame object by the front_frame object as seen from the observer, when according for the provided aberration correction.
A zero percent occultation means that the back object is fully visible from the observer. A 100% percent occultation means that the back object is fully hidden from the observer because of the front frame (i.e. umbra if the back object is the Sun). A value in between means that the back object is partially hidden from the observser (i.e. penumbra if the back object is the Sun). Refer to the MathSpec for modeling details.
pub fn solar_eclipsing(
&self,
eclipsing_frame: Frame,
observer: CartesianState,
ab_corr: Option<Aberration>,
) -> Result<Occultation, AlmanacError>
pub fn solar_eclipsing( &self, eclipsing_frame: Frame, observer: CartesianState, ab_corr: Option<Aberration>, ) -> Result<Occultation, AlmanacError>
Computes the solar eclipsing of the observer due to the eclipsing_frame.
This function calls occultation where the back object is the Sun in the J2000 frame, and the front object
is the provided eclipsing frame.
:type eclipsing_frame: Frame :type observer: Orbit :type ab_corr: Aberration, optional :rtype: Occultation
pub fn beta_angle_deg(
&self,
state: CartesianState,
ab_corr: Option<Aberration>,
) -> Result<f64, AlmanacError>
pub fn beta_angle_deg( &self, state: CartesianState, ab_corr: Option<Aberration>, ) -> Result<f64, AlmanacError>
Computes the Beta angle (β) for a given orbital state, in degrees. A Beta angle of 0° indicates that the orbit plane is edge-on to the Sun, leading to maximum eclipse time. Conversely, a Beta angle of +90° or -90° means the orbit plane is face-on to the Sun, resulting in continuous sunlight exposure and no eclipses.
The Beta angle (β) is defined as the angle between the orbit plane of a spacecraft and the vector from the central body (e.g., Earth) to the Sun. In simpler terms, it measures how much of the time a satellite in orbit is exposed to direct sunlight. The mathematical formula for the Beta angle is: β=arcsin(h⋅usun) Where:
- h is the unit vector of the orbital momentum.
- usun is the unit vector pointing from the central body to the Sun.
Original code from GMAT, https://github.com/ChristopherRabotin/GMAT/blob/GMAT-R2022a/src/gmatutil/util/CalculationUtilities.cpp#L209-L219
pub fn local_solar_time(
&self,
state: CartesianState,
ab_corr: Option<Aberration>,
) -> Result<Duration, AlmanacError>
pub fn local_solar_time( &self, state: CartesianState, ab_corr: Option<Aberration>, ) -> Result<Duration, AlmanacError>
Compute the local solar time, returned as a Duration between 0 and 24 hours.
pub fn ltan(
&self,
orbit: CartesianState,
ab_corr: Option<Aberration>,
) -> Result<Duration, AlmanacError>
pub fn ltan( &self, orbit: CartesianState, ab_corr: Option<Aberration>, ) -> Result<Duration, AlmanacError>
Returns the Local Time of the Ascending Node (LTAN). This is the local time on the celestial body at which the spacecraft crosses the equator from south to north.
The formula is from Wertz, “Spacecraft Attitude Determination and Control”, page 79, equation (4-8). LTAN (hours) = 12.0 + (RAAN_orbit - RA_sun) / 15.0
:type orbit: Orbit :type ab_corr: Aberration, optional :rtype: Duration
pub fn ltdn(
&self,
orbit: CartesianState,
ab_corr: Option<Aberration>,
) -> Result<Duration, AlmanacError>
pub fn ltdn( &self, orbit: CartesianState, ab_corr: Option<Aberration>, ) -> Result<Duration, AlmanacError>
Returns the Local Time of the Descending Node (LTDN) in hours. This is the local time on the celestial body at which the spacecraft crosses the equator from north to south.
LTDN is 12 hours after LTAN.
:type orbit: Orbit :type ab_corr: Aberration, optional :rtype: Duration
§impl Almanac
impl Almanac
pub fn instrument_from_id(&self, id: i32) -> Result<Instrument, AlmanacError>
pub fn instrument_from_id(&self, id: i32) -> Result<Instrument, AlmanacError>
Returns the Instrument from its ID, searching through all loaded instrument datasets in reverse order.
pub fn instrument_from_name(
&self,
name: &str,
) -> Result<Instrument, AlmanacError>
pub fn instrument_from_name( &self, name: &str, ) -> Result<Instrument, AlmanacError>
Returns the Instrument Location from its name, searching through all loaded instrument datasets in reverse order.
pub fn instrument_field_of_view_margin( &self, instrument_id: i32, sc_q_to_b: EulerParameter, sc_state: CartesianState, target_state: CartesianState, ) -> Result<f64, AlmanacError>
§impl Almanac
impl Almanac
pub fn frame_from_uid<U>(&self, uid: U) -> Result<Frame, PlanetaryDataError>
👎Deprecated since 0.7.0: use frame_info instead
pub fn frame_from_uid<U>(&self, uid: U) -> Result<Frame, PlanetaryDataError>
Given the frame UID (or something that can be transformed into it), attempt to retrieve the full frame information, if that frame is loaded
pub fn frame_info<U>(&self, uid: U) -> Result<Frame, PlanetaryDataError>
pub fn frame_info<U>(&self, uid: U) -> Result<Frame, PlanetaryDataError>
Given the frame UID (or something that can be transformed into it), attempt to retrieve the full frame information, if that frame is loaded
Examples found in repository?
28fn main() -> Result<(), Box<dyn Error>> {
29 pel::init();
30 // Set up the dynamics like in the orbit raise.
31 let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
32 let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
33
34 // Define the GEO orbit, and we're just going to maintain it very tightly.
35 let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
36 let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
37 println!("{orbit:x}");
38
39 let sc = Spacecraft::builder()
40 .orbit(orbit)
41 .mass(Mass::from_dry_and_prop_masses(1000.0, 1000.0)) // 1000 kg of dry mass and prop, totalling 2.0 tons
42 .srp(SRPData::from_area(3.0 * 6.0)) // Assuming 1 kW/m^2 or 18 kW, giving a margin of 4.35 kW for on-propulsion consumption
43 .thruster(Thruster {
44 // "NEXT-STEP" row in Table 2
45 isp_s: 4435.0,
46 thrust_N: 0.472,
47 })
48 .mode(GuidanceMode::Thrust) // Start thrusting immediately.
49 .build();
50
51 // Set up the spacecraft dynamics like in the orbit raise example.
52
53 let prop_time = 30.0 * Unit::Day;
54
55 // Define the guidance law -- we're just using a Ruggiero controller as demonstrated in AAS-2004-5089.
56 let objectives = &[
57 Objective::within_tolerance(
58 StateParameter::Element(OrbitalElement::SemiMajorAxis),
59 42_165.0,
60 20.0,
61 ),
62 Objective::within_tolerance(
63 StateParameter::Element(OrbitalElement::Eccentricity),
64 0.001,
65 5e-5,
66 ),
67 Objective::within_tolerance(
68 StateParameter::Element(OrbitalElement::Inclination),
69 0.05,
70 1e-2,
71 ),
72 ];
73
74 let ruggiero_ctrl = Ruggiero::from_max_eclipse(objectives, sc, 0.2)?;
75 println!("{ruggiero_ctrl}");
76
77 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
78
79 let mut jgm3_meta = MetaFile {
80 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
81 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
82 };
83 jgm3_meta.process(true)?;
84
85 let harmonics = Harmonics::from_stor(
86 almanac.frame_info(IAU_EARTH_FRAME)?,
87 HarmonicsMem::from_cof(&jgm3_meta.uri, 8, 8, true)?,
88 );
89 orbital_dyn.accel_models.push(harmonics);
90
91 let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
92 let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
93 .with_guidance_law(ruggiero_ctrl.clone());
94
95 println!("{sc_dynamics}");
96
97 // Finally, let's use the Monte Carlo framework built into Nyx to propagate spacecraft.
98
99 // Let's start by defining the dispersion.
100 // The MultivariateNormal structure allows us to define the dispersions in any of the orbital parameters, but these are applied directly in the Cartesian state space.
101 // Note that additional validation on the MVN is in progress -- https://github.com/nyx-space/nyx/issues/339.
102 let mc_rv = MvnSpacecraft::new(
103 sc,
104 vec![StateDispersion::zero_mean(
105 StateParameter::Element(OrbitalElement::SemiMajorAxis),
106 3.0,
107 )],
108 )?;
109
110 let my_mc = MonteCarlo::new(
111 sc, // Nominal state
112 mc_rv,
113 "03_geo_sk".to_string(), // Scenario name
114 None, // No specific seed specified, so one will be drawn from the computer's entropy.
115 );
116
117 // Build the propagator setup.
118 let setup = Propagator::rk89(
119 sc_dynamics.clone(),
120 IntegratorOptions::builder()
121 .min_step(10.0_f64.seconds())
122 .error_ctrl(ErrorControl::RSSCartesianStep)
123 .build(),
124 );
125
126 let num_runs = 25;
127 let rslts = my_mc.run_until_epoch(setup, almanac.clone(), sc.epoch() + prop_time, num_runs);
128
129 assert_eq!(rslts.runs.len(), num_runs);
130
131 rslts.to_parquet("03_geo_sk.parquet", ExportCfg::default())?;
132
133 Ok(())
134}More examples
27fn main() -> Result<(), Box<dyn Error>> {
28 pel::init();
29
30 // Dynamics models require planetary constants and ephemerides to be defined.
31 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
32 // This will automatically download the DE440s planetary ephemeris,
33 // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
34 // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
35 // planetary constants kernels.
36 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
37 // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
38 // references to many functions.
39 let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
40 // Fetch the EME2000 frame from the Almabac
41 let eme2k = almanac.frame_info(EARTH_J2000).unwrap();
42 // Define the orbit epoch
43 let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
44
45 // Build the spacecraft itself.
46 // Using slide 6 of https://aerospace.org/sites/default/files/2018-11/Davis-Mayberry_HPSEP_11212018.pdf
47 // for the "next gen" SEP characteristics.
48
49 // GTO start
50 let orbit = Orbit::keplerian(24505.9, 0.725, 7.05, 0.0, 0.0, 0.0, epoch, eme2k);
51
52 let sc = Spacecraft::builder()
53 .orbit(orbit)
54 .mass(Mass::from_dry_and_prop_masses(1000.0, 1000.0)) // 1000 kg of dry mass and prop, totalling 2.0 tons
55 .srp(SRPData::from_area(3.0 * 6.0)) // Assuming 1 kW/m^2 or 18 kW, giving a margin of 4.35 kW for on-propulsion consumption
56 .thruster(Thruster {
57 // "NEXT-STEP" row in Table 2
58 isp_s: 4435.0,
59 thrust_N: 0.472,
60 })
61 .mode(GuidanceMode::Thrust) // Start thrusting immediately.
62 .build();
63
64 let prop_time = 180.0 * Unit::Day;
65
66 // Define the guidance law -- we're just using a Ruggiero controller as demonstrated in AAS-2004-5089.
67 let objectives = &[
68 Objective::within_tolerance(
69 StateParameter::Element(OrbitalElement::SemiMajorAxis),
70 42_165.0,
71 20.0,
72 ),
73 Objective::within_tolerance(
74 StateParameter::Element(OrbitalElement::Eccentricity),
75 0.001,
76 5e-5,
77 ),
78 Objective::within_tolerance(
79 StateParameter::Element(OrbitalElement::Inclination),
80 0.05,
81 1e-2,
82 ),
83 ];
84
85 // Ensure that we only thrust if we have more than 20% illumination.
86 let ruggiero_ctrl = Ruggiero::from_max_eclipse(objectives, sc, 0.2).unwrap();
87 println!("{ruggiero_ctrl}");
88
89 // Define the high fidelity dynamics
90
91 // Set up the spacecraft dynamics.
92
93 // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
94 // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
95 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
96
97 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
98 // We're using the JGM3 model here, which is the default in GMAT.
99 let mut jgm3_meta = MetaFile {
100 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
101 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
102 };
103 // And let's download it if we don't have it yet.
104 jgm3_meta.process(true)?;
105
106 // Build the spherical harmonics.
107 // The harmonics must be computed in the body fixed frame.
108 // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
109 let harmonics = Harmonics::from_stor(
110 almanac.frame_info(IAU_EARTH_FRAME)?,
111 HarmonicsMem::from_cof(&jgm3_meta.uri, 8, 8, true).unwrap(),
112 );
113
114 // Include the spherical harmonics into the orbital dynamics.
115 orbital_dyn.accel_models.push(harmonics);
116
117 // We define the solar radiation pressure, using the default solar flux and accounting only
118 // for the eclipsing caused by the Earth.
119 let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
120
121 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
122 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
123 let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
124 .with_guidance_law(ruggiero_ctrl.clone());
125
126 println!("{orbit:x}");
127
128 // We specify a minimum step in the propagator because the Ruggiero control would otherwise drive this step very low.
129 let (final_state, traj) = Propagator::rk89(
130 sc_dynamics.clone(),
131 IntegratorOptions::builder()
132 .min_step(10.0_f64.seconds())
133 .error_ctrl(ErrorControl::RSSCartesianStep)
134 .build(),
135 )
136 .with(sc, almanac.clone())
137 .for_duration_with_traj(prop_time)?;
138
139 let prop_usage = sc.mass.prop_mass_kg - final_state.mass.prop_mass_kg;
140 println!("{:x}", final_state.orbit);
141 println!("prop usage: {prop_usage:.3} kg");
142
143 // Finally, export the results for analysis, including the penumbra percentage throughout the orbit raise.
144 traj.to_parquet("./03_geo_raise.parquet", ExportCfg::default())?;
145
146 for status_line in ruggiero_ctrl.status(&final_state) {
147 println!("{status_line}");
148 }
149
150 ruggiero_ctrl
151 .achieved(&final_state)
152 .expect("objective not achieved");
153
154 Ok(())
155}34fn main() -> Result<(), Box<dyn Error>> {
35 pel::init();
36
37 // ====================== //
38 // === ALMANAC SET UP === //
39 // ====================== //
40
41 let manifest_dir =
42 PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap_or(".".to_string()));
43
44 let out = manifest_dir.join("data/04_output/");
45
46 let almanac = Arc::new(
47 Almanac::new(
48 &manifest_dir
49 .join("data/01_planetary/pck08.pca")
50 .to_string_lossy(),
51 )
52 .unwrap()
53 .load(
54 &manifest_dir
55 .join("data/01_planetary/de440s.bsp")
56 .to_string_lossy(),
57 )
58 .unwrap(),
59 );
60
61 let eme2k = almanac.frame_info(EARTH_J2000).unwrap();
62 let moon_iau = almanac.frame_info(IAU_MOON_FRAME).unwrap();
63
64 let epoch = Epoch::from_gregorian_tai(2021, 5, 29, 19, 51, 16, 852_000);
65 let nrho = Orbit::cartesian(
66 166_473.631_302_239_7,
67 -274_715.487_253_382_7,
68 -211_233.210_176_686_7,
69 0.933_451_604_520_018_4,
70 0.436_775_046_841_900_9,
71 -0.082_211_021_250_348_95,
72 epoch,
73 eme2k,
74 );
75
76 let tx_nrho_sc = Spacecraft::from(nrho);
77
78 let state_luna = almanac.transform_to(nrho, MOON_J2000, None).unwrap();
79 println!("Start state (dynamics: Earth, Moon, Sun gravity):\n{state_luna}");
80
81 let bodies = vec![EARTH, SUN];
82 let dynamics = SpacecraftDynamics::new(OrbitalDynamics::point_masses(bodies));
83
84 let setup = Propagator::rk89(
85 dynamics,
86 IntegratorOptions::builder().max_step(0.5.minutes()).build(),
87 );
88
89 /* == Propagate the NRHO vehicle == */
90 let prop_time = 1.1 * state_luna.period().unwrap();
91
92 let (nrho_final, mut tx_traj) = setup
93 .with(tx_nrho_sc, almanac.clone())
94 .for_duration_with_traj(prop_time)
95 .unwrap();
96
97 tx_traj.name = Some("NRHO Tx SC".to_string());
98
99 println!("{tx_traj}");
100
101 /* == Propagate an LLO vehicle == */
102 let llo_orbit =
103 Orbit::try_keplerian_altitude(110.0, 1e-4, 90.0, 0.0, 0.0, 0.0, epoch, moon_iau).unwrap();
104
105 let llo_sc = Spacecraft::builder().orbit(llo_orbit).build();
106
107 let (_, llo_traj) = setup
108 .with(llo_sc, almanac.clone())
109 .until_epoch_with_traj(nrho_final.epoch())
110 .unwrap();
111
112 // Export the subset of the first two hours.
113 llo_traj
114 .clone()
115 .filter_by_offset(..2.hours())
116 .to_parquet_simple(out.join("05_caps_llo_truth.pq"))?;
117
118 /* == Setup the interlink == */
119
120 let mut measurement_types = IndexSet::new();
121 measurement_types.insert(MeasurementType::Range);
122 measurement_types.insert(MeasurementType::Doppler);
123
124 let mut stochastics = IndexMap::new();
125
126 let sa45_csac_allan_dev = 1e-11;
127
128 stochastics.insert(
129 MeasurementType::Range,
130 StochasticNoise::from_hardware_range_km(
131 sa45_csac_allan_dev,
132 10.0.seconds(),
133 link_specific::ChipRate::StandardT4B,
134 link_specific::SN0::Average,
135 ),
136 );
137
138 stochastics.insert(
139 MeasurementType::Doppler,
140 StochasticNoise::from_hardware_doppler_km_s(
141 sa45_csac_allan_dev,
142 10.0.seconds(),
143 link_specific::CarrierFreq::SBand,
144 link_specific::CN0::Average,
145 ),
146 );
147
148 let interlink = InterlinkTxSpacecraft {
149 traj: tx_traj,
150 measurement_types,
151 integration_time: None,
152 timestamp_noise_s: None,
153 ab_corr: Aberration::LT,
154 stochastic_noises: Some(stochastics),
155 };
156
157 // Devices are the transmitter, which is our NRHO vehicle.
158 let mut devices = BTreeMap::new();
159 devices.insert("NRHO Tx SC".to_string(), interlink);
160
161 let mut configs = BTreeMap::new();
162 configs.insert(
163 "NRHO Tx SC".to_string(),
164 TrkConfig::builder()
165 .strands(vec![Strand {
166 start: epoch,
167 end: nrho_final.epoch(),
168 }])
169 .build(),
170 );
171
172 let mut trk_sim =
173 TrackingArcSim::with_seed(devices.clone(), llo_traj.clone(), configs, 0).unwrap();
174 println!("{trk_sim}");
175
176 let trk_data = trk_sim.generate_measurements(almanac.clone()).unwrap();
177 println!("{trk_data}");
178
179 trk_data
180 .to_parquet_simple(out.clone().join("nrho_interlink_msr.pq"))
181 .unwrap();
182
183 // Run a truth OD where we estimate the LLO position
184 let llo_uncertainty = SpacecraftUncertainty::builder()
185 .nominal(llo_sc)
186 .x_km(1.0)
187 .y_km(1.0)
188 .z_km(1.0)
189 .vx_km_s(1e-3)
190 .vy_km_s(1e-3)
191 .vz_km_s(1e-3)
192 .build();
193
194 let mut proc_devices = devices.clone();
195
196 // Define the initial estimate, randomized, seed for reproducibility
197 let mut initial_estimate = llo_uncertainty.to_estimate_randomized(Some(0)).unwrap();
198 // Inflate the covariance -- https://github.com/nyx-space/nyx/issues/339
199 initial_estimate.covar *= 2.5;
200
201 // Increase the noise in the devices to accept more measurements.
202
203 for link in proc_devices.values_mut() {
204 for noise in &mut link.stochastic_noises.as_mut().unwrap().values_mut() {
205 *noise.white_noise.as_mut().unwrap() *= 3.0;
206 }
207 }
208
209 let init_err = initial_estimate
210 .orbital_state()
211 .ric_difference(&llo_orbit)
212 .unwrap();
213
214 println!("initial estimate:\n{initial_estimate}");
215 println!("RIC errors = {init_err}",);
216
217 let odp = InterlinkKalmanOD::new(
218 setup.clone(),
219 KalmanVariant::ReferenceUpdate,
220 Some(ResidRejectCrit::default()),
221 proc_devices,
222 almanac.clone(),
223 );
224
225 // Shrink the data to process.
226 let arc = trk_data.filter_by_offset(..2.hours());
227
228 let od_sol = odp.process_arc(initial_estimate, &arc).unwrap();
229
230 println!("{od_sol}");
231
232 od_sol
233 .to_parquet(
234 out.join("05_caps_interlink_od_sol.pq"),
235 ExportCfg::default(),
236 )
237 .unwrap();
238
239 let od_traj = od_sol.to_traj().unwrap();
240
241 od_traj
242 .ric_diff_to_parquet(
243 &llo_traj,
244 out.join("05_caps_interlink_llo_est_error.pq"),
245 ExportCfg::default(),
246 )
247 .unwrap();
248
249 let final_est = od_sol.estimates.last().unwrap();
250 assert!(final_est.within_3sigma(), "should be within 3 sigma");
251
252 println!("ESTIMATE\n{final_est:x}\n");
253 let truth = llo_traj.at(final_est.epoch()).unwrap();
254 println!("TRUTH\n{truth:x}");
255
256 let final_err = truth
257 .orbit
258 .ric_difference(&final_est.orbital_state())
259 .unwrap();
260 println!("ERROR {final_err}");
261
262 // Build the residuals versus reference plot.
263 let rvr_sol = odp
264 .process_arc(initial_estimate, &arc.resid_vs_ref_check())
265 .unwrap();
266
267 rvr_sol
268 .to_parquet(
269 out.join("05_caps_interlink_resid_v_ref.pq"),
270 ExportCfg::default(),
271 )
272 .unwrap();
273
274 let final_rvr = rvr_sol.estimates.last().unwrap();
275
276 println!("RMAG error {:.3} m", final_err.rmag_km() * 1e3);
277 println!(
278 "Pure prop error {:.3} m",
279 final_rvr
280 .orbital_state()
281 .ric_difference(&final_est.orbital_state())
282 .unwrap()
283 .rmag_km()
284 * 1e3
285 );
286
287 Ok(())
288}26fn main() -> Result<(), Box<dyn Error>> {
27 pel::init();
28 // Dynamics models require planetary constants and ephemerides to be defined.
29 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
30 // This will automatically download the DE440s planetary ephemeris,
31 // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
32 // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
33 // planetary constants kernels.
34 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
35 // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
36 // references to many functions.
37 let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
38 // Define the orbit epoch
39 let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
40
41 // Define the orbit.
42 // First we need to fetch the Earth J2000 from information from the Almanac.
43 // This allows the frame to include the gravitational parameters and the shape of the Earth,
44 // defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
45 // by loading a different set of planetary constants.
46 let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
47
48 // Placing this GEO bird just above Colorado.
49 // In theory, the eccentricity is zero, but in practice, it's about 1e-5 to 1e-6 at best.
50 let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
51 // Print in in Keplerian form.
52 println!("{orbit:x}");
53
54 let state_bf = almanac.transform_to(orbit, IAU_EARTH_FRAME, None)?;
55 let (orig_lat_deg, orig_long_deg, orig_alt_km) = state_bf.latlongalt()?;
56
57 // Nyx is used for high fidelity propagation, not Keplerian propagation as above.
58 // Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
59 // models such as solar radiation pressure.
60
61 // Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
62 let sc = Spacecraft::builder()
63 .orbit(orbit)
64 .mass(Mass::from_dry_mass(9.60))
65 .srp(SRPData {
66 area_m2: 10e-4,
67 coeff_reflectivity: 1.1,
68 })
69 .build();
70 println!("{sc:x}");
71
72 // Set up the spacecraft dynamics.
73
74 // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
75 // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
76 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
77
78 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
79 // We're using the JGM3 model here, which is the default in GMAT.
80 let mut jgm3_meta = MetaFile {
81 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
82 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
83 };
84 // And let's download it if we don't have it yet.
85 jgm3_meta.process(true)?;
86
87 // Build the spherical harmonics.
88 // The harmonics must be computed in the body fixed frame.
89 // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
90 let harmonics_21x21 = Harmonics::from_stor(
91 almanac.frame_info(IAU_EARTH_FRAME)?,
92 HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
93 );
94
95 // Include the spherical harmonics into the orbital dynamics.
96 orbital_dyn.accel_models.push(harmonics_21x21);
97
98 // We define the solar radiation pressure, using the default solar flux and accounting only
99 // for the eclipsing caused by the Earth and Moon.
100 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
101
102 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
103 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
104 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
105
106 println!("{dynamics}");
107
108 // Finally, let's propagate this orbit to the same epoch as above.
109 // The first returned value is the spacecraft state at the final epoch.
110 // The second value is the full trajectory where the step size is variable step used by the propagator.
111 let (future_sc, trajectory) = Propagator::default(dynamics)
112 .with(sc, almanac.clone())
113 .until_epoch_with_traj(epoch + Unit::Century * 0.03)?;
114
115 println!("=== High fidelity propagation ===");
116 println!(
117 "SMA changed by {:.3} km",
118 orbit.sma_km()? - future_sc.orbit.sma_km()?
119 );
120 println!(
121 "ECC changed by {:.6}",
122 orbit.ecc()? - future_sc.orbit.ecc()?
123 );
124 println!(
125 "INC changed by {:.3e} deg",
126 orbit.inc_deg()? - future_sc.orbit.inc_deg()?
127 );
128 println!(
129 "RAAN changed by {:.3} deg",
130 orbit.raan_deg()? - future_sc.orbit.raan_deg()?
131 );
132 println!(
133 "AOP changed by {:.3} deg",
134 orbit.aop_deg()? - future_sc.orbit.aop_deg()?
135 );
136 println!(
137 "TA changed by {:.3} deg",
138 orbit.ta_deg()? - future_sc.orbit.ta_deg()?
139 );
140
141 // We also have access to the full trajectory throughout the propagation.
142 println!("{trajectory}");
143
144 println!("Spacecraft params after 3 years without active control:\n{future_sc:x}");
145
146 // With the trajectory, let's build a few data products.
147
148 // 1. Export the trajectory as a parquet file, which includes the Keplerian orbital elements.
149
150 let analysis_step = Unit::Minute * 5;
151
152 trajectory.to_parquet(
153 "./03_geo_hf_prop.parquet",
154 ExportCfg::builder().step(analysis_step).build(),
155 )?;
156
157 // 2. Compute the latitude, longitude, and altitude throughout the trajectory by rotating the spacecraft position into the Earth body fixed frame.
158
159 // We iterate over the trajectory, grabbing a state every two minutes.
160 let mut offset_s = vec![];
161 let mut epoch_str = vec![];
162 let mut longitude_deg = vec![];
163 let mut latitude_deg = vec![];
164 let mut altitude_km = vec![];
165
166 for state in trajectory.every(analysis_step) {
167 // Convert the GEO bird state into the body fixed frame, and keep track of its latitude, longitude, and altitude.
168 // These define the GEO stationkeeping box.
169
170 let this_epoch = state.epoch();
171
172 offset_s.push((this_epoch - orbit.epoch).to_seconds());
173 epoch_str.push(this_epoch.to_isoformat());
174
175 let state_bf = almanac.transform_to(state.orbit, IAU_EARTH_FRAME, None)?;
176 let (lat_deg, long_deg, alt_km) = state_bf.latlongalt()?;
177 longitude_deg.push(long_deg);
178 latitude_deg.push(lat_deg);
179 altitude_km.push(alt_km);
180 }
181
182 println!(
183 "Longitude changed by {:.3} deg -- Box is 0.1 deg E-W",
184 orig_long_deg - longitude_deg.last().unwrap()
185 );
186
187 println!(
188 "Latitude changed by {:.3} deg -- Box is 0.05 deg N-S",
189 orig_lat_deg - latitude_deg.last().unwrap()
190 );
191
192 println!(
193 "Altitude changed by {:.3} km -- Box is 30 km",
194 orig_alt_km - altitude_km.last().unwrap()
195 );
196
197 // Build the station keeping data frame.
198 let mut sk_df = df!(
199 "Offset (s)" => offset_s.clone(),
200 "Epoch (UTC)" => epoch_str.clone(),
201 "Longitude E-W (deg)" => longitude_deg,
202 "Latitude N-S (deg)" => latitude_deg,
203 "Altitude (km)" => altitude_km,
204
205 )?;
206
207 // Create a file to write the Parquet to
208 let file = File::create("./03_geo_lla.parquet").expect("Could not create file");
209
210 // Create a ParquetWriter and write the DataFrame to the file
211 ParquetWriter::new(file).finish(&mut sk_df)?;
212
213 Ok(())
214}30fn main() -> Result<(), Box<dyn Error>> {
31 pel::init();
32 // Dynamics models require planetary constants and ephemerides to be defined.
33 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
34 // This will automatically download the DE440s planetary ephemeris,
35 // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
36 // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
37 // planetary constants kernels.
38 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
39 // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
40 // references to many functions.
41 let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
42 // Define the orbit epoch
43 let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
44
45 // Define the orbit.
46 // First we need to fetch the Earth J2000 from information from the Almanac.
47 // This allows the frame to include the gravitational parameters and the shape of the Earth,
48 // defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
49 // by loading a different set of planetary constants.
50 let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
51
52 let orbit =
53 Orbit::try_keplerian_altitude(300.0, 0.015, 68.5, 65.2, 75.0, 0.0, epoch, earth_j2000)?;
54 // Print in in Keplerian form.
55 println!("{orbit:x}");
56
57 // There are two ways to propagate an orbit. We can make a quick approximation assuming only two-body
58 // motion. This is a useful first order approximation but it isn't used in real-world applications.
59
60 // This approach is a feature of ANISE.
61 let future_orbit_tb = orbit.at_epoch(epoch + Unit::Day * 3)?;
62 println!("{future_orbit_tb:x}");
63
64 // Two body propagation relies solely on Kepler's laws, so only the true anomaly will change.
65 println!(
66 "SMA changed by {:.3e} km",
67 orbit.sma_km()? - future_orbit_tb.sma_km()?
68 );
69 println!(
70 "ECC changed by {:.3e}",
71 orbit.ecc()? - future_orbit_tb.ecc()?
72 );
73 println!(
74 "INC changed by {:.3e} deg",
75 orbit.inc_deg()? - future_orbit_tb.inc_deg()?
76 );
77 println!(
78 "RAAN changed by {:.3e} deg",
79 orbit.raan_deg()? - future_orbit_tb.raan_deg()?
80 );
81 println!(
82 "AOP changed by {:.3e} deg",
83 orbit.aop_deg()? - future_orbit_tb.aop_deg()?
84 );
85 println!(
86 "TA changed by {:.3} deg",
87 orbit.ta_deg()? - future_orbit_tb.ta_deg()?
88 );
89
90 // Nyx is used for high fidelity propagation, not Keplerian propagation as above.
91 // Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
92 // models such as solar radiation pressure.
93
94 // Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
95 let sc = Spacecraft::builder()
96 .orbit(orbit)
97 .mass(Mass::from_dry_mass(9.60))
98 .srp(SRPData {
99 area_m2: 10e-4,
100 coeff_reflectivity: 1.1,
101 })
102 .build();
103 println!("{sc:x}");
104
105 // Set up the spacecraft dynamics.
106
107 // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
108 // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
109 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
110
111 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
112 // We're using the JGM3 model here, which is the default in GMAT.
113 let mut jgm3_meta = MetaFile {
114 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
115 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
116 };
117 // And let's download it if we don't have it yet.
118 jgm3_meta.process(true)?;
119
120 // Build the spherical harmonics.
121 // The harmonics must be computed in the body fixed frame.
122 // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
123 let harmonics_21x21 = Harmonics::from_stor(
124 almanac.frame_info(IAU_EARTH_FRAME)?,
125 HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
126 );
127
128 // Include the spherical harmonics into the orbital dynamics.
129 orbital_dyn.accel_models.push(harmonics_21x21);
130
131 // We define the solar radiation pressure, using the default solar flux and accounting only
132 // for the eclipsing caused by the Earth.
133 let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
134
135 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
136 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
137 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
138
139 println!("{dynamics}");
140
141 // Finally, let's propagate this orbit to the same epoch as above.
142 // The first returned value is the spacecraft state at the final epoch.
143 // The second value is the full trajectory where the step size is variable step used by the propagator.
144 let (future_sc, trajectory) = Propagator::default(dynamics)
145 .with(sc, almanac.clone())
146 .until_epoch_with_traj(future_orbit_tb.epoch)?;
147
148 println!("=== High fidelity propagation ===");
149 println!(
150 "SMA changed by {:.3} km",
151 orbit.sma_km()? - future_sc.orbit.sma_km()?
152 );
153 println!(
154 "ECC changed by {:.6}",
155 orbit.ecc()? - future_sc.orbit.ecc()?
156 );
157 println!(
158 "INC changed by {:.3e} deg",
159 orbit.inc_deg()? - future_sc.orbit.inc_deg()?
160 );
161 println!(
162 "RAAN changed by {:.3} deg",
163 orbit.raan_deg()? - future_sc.orbit.raan_deg()?
164 );
165 println!(
166 "AOP changed by {:.3} deg",
167 orbit.aop_deg()? - future_sc.orbit.aop_deg()?
168 );
169 println!(
170 "TA changed by {:.3} deg",
171 orbit.ta_deg()? - future_sc.orbit.ta_deg()?
172 );
173
174 // We also have access to the full trajectory throughout the propagation.
175 println!("{trajectory}");
176
177 // With the trajectory, let's build a few data products.
178
179 // 1. Export the trajectory as a CCSDS OEM version 2.0 file and as a parquet file, which includes the Keplerian orbital elements.
180
181 trajectory.to_oem_file(
182 "./01_cubesat_hf_prop.oem",
183 ExportCfg::builder().step(Unit::Minute * 2).build(),
184 )?;
185
186 trajectory.to_parquet_with_cfg(
187 "./01_cubesat_hf_prop.parquet",
188 ExportCfg::builder().step(Unit::Minute * 2).build(),
189 )?;
190
191 // 2. Compare the difference in the radial-intrack-crosstrack frame between the high fidelity
192 // and Keplerian propagation. The RIC frame is commonly used to compute the difference in position
193 // and velocity of different spacecraft.
194 // 3. Compute the azimuth, elevation, range, and range-rate data of that spacecraft as seen from Boulder, CO, USA.
195
196 let boulder_station = GroundStation::from_point(
197 "Boulder, CO, USA".to_string(),
198 40.014984, // latitude in degrees
199 -105.270546, // longitude in degrees
200 1.6550, // altitude in kilometers
201 almanac.frame_info(IAU_EARTH_FRAME)?,
202 );
203
204 // We iterate over the trajectory, grabbing a state every two minutes.
205 let mut offset_s = vec![];
206 let mut epoch_str = vec![];
207 let mut ric_x_km = vec![];
208 let mut ric_y_km = vec![];
209 let mut ric_z_km = vec![];
210 let mut ric_vx_km_s = vec![];
211 let mut ric_vy_km_s = vec![];
212 let mut ric_vz_km_s = vec![];
213
214 let mut azimuth_deg = vec![];
215 let mut elevation_deg = vec![];
216 let mut range_km = vec![];
217 let mut range_rate_km_s = vec![];
218 for state in trajectory.every(Unit::Minute * 2) {
219 // Try to compute the Keplerian/two body state just in time.
220 // This method occasionally fails to converge on an appropriate true anomaly
221 // from the mean anomaly. If that happens, we just skip this state.
222 // The high fidelity and Keplerian states diverge continuously, and we're curious
223 // about the divergence in this quick analysis.
224 let this_epoch = state.epoch();
225 match orbit.at_epoch(this_epoch) {
226 Ok(tb_then) => {
227 offset_s.push((this_epoch - orbit.epoch).to_seconds());
228 epoch_str.push(format!("{this_epoch}"));
229 // Compute the two body state just in time.
230 let ric = state.orbit.ric_difference(&tb_then)?;
231 ric_x_km.push(ric.radius_km.x);
232 ric_y_km.push(ric.radius_km.y);
233 ric_z_km.push(ric.radius_km.z);
234 ric_vx_km_s.push(ric.velocity_km_s.x);
235 ric_vy_km_s.push(ric.velocity_km_s.y);
236 ric_vz_km_s.push(ric.velocity_km_s.z);
237
238 // Compute the AER data for each state.
239 let aer = almanac.azimuth_elevation_range_sez(
240 state.orbit,
241 boulder_station.to_orbit(this_epoch, &almanac)?,
242 None,
243 None,
244 )?;
245 azimuth_deg.push(aer.azimuth_deg);
246 elevation_deg.push(aer.elevation_deg);
247 range_km.push(aer.range_km);
248 range_rate_km_s.push(aer.range_rate_km_s);
249 }
250 Err(e) => warn!("{} {e}", state.epoch()),
251 };
252 }
253
254 // Build the data frames.
255 let ric_df = df!(
256 "Offset (s)" => offset_s.clone(),
257 "Epoch" => epoch_str.clone(),
258 "RIC X (km)" => ric_x_km,
259 "RIC Y (km)" => ric_y_km,
260 "RIC Z (km)" => ric_z_km,
261 "RIC VX (km/s)" => ric_vx_km_s,
262 "RIC VY (km/s)" => ric_vy_km_s,
263 "RIC VZ (km/s)" => ric_vz_km_s,
264 )?;
265
266 println!("RIC difference at start\n{}", ric_df.head(Some(10)));
267 println!("RIC difference at end\n{}", ric_df.tail(Some(10)));
268
269 let aer_df = df!(
270 "Offset (s)" => offset_s.clone(),
271 "Epoch" => epoch_str.clone(),
272 "azimuth (deg)" => azimuth_deg,
273 "elevation (deg)" => elevation_deg,
274 "range (km)" => range_km,
275 "range rate (km/s)" => range_rate_km_s,
276 )?;
277
278 // Finally, let's see when the spacecraft is visible, assuming 15 degrees minimum elevation.
279 let mask = aer_df
280 .column("elevation (deg)")?
281 .gt(&Column::Scalar(ScalarColumn::new(
282 "elevation mask (deg)".into(),
283 Scalar::new(DataType::Float64, AnyValue::Float64(15.0)),
284 offset_s.len(),
285 )))?;
286 let cubesat_visible = aer_df.filter(&mask)?;
287
288 println!("{cubesat_visible}");
289
290 Ok(())
291}35fn main() -> Result<(), Box<dyn Error>> {
36 pel::init();
37
38 // ====================== //
39 // === ALMANAC SET UP === //
40 // ====================== //
41
42 // Dynamics models require planetary constants and ephemerides to be defined.
43 // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45 let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
46 .iter()
47 .collect();
48
49 let meta = data_folder.join("lro-dynamics.dhall");
50
51 // Load this ephem in the general Almanac we're using for this analysis.
52 let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
53 .map_err(Box::new)?
54 .process(true)
55 .map_err(Box::new)?;
56
57 let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
58 moon_pc.mu_km3_s2 = 4902.74987;
59 almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
60
61 let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
62 earth.mu_km3_s2 = 398600.436;
63 almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
64
65 // Save this new kernel for reuse.
66 // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
67 almanac
68 .planetary_data
69 .values()
70 .next()
71 .unwrap()
72 .save_as(&data_folder.join("lro-specific.pca"), true)?;
73
74 // Lock the almanac (an Arc is a read only structure).
75 let almanac = Arc::new(almanac);
76
77 // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
78 // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
79 // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
80 // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
81 let lro_frame = Frame::from_ephem_j2000(-85);
82
83 // To build the trajectory we need to provide a spacecraft template.
84 let sc_template = Spacecraft::builder()
85 .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
86 .srp(SRPData {
87 // SRP configuration is arbitrary, but we will be estimating it anyway.
88 area_m2: 3.9 * 2.7,
89 coeff_reflectivity: 0.96,
90 })
91 .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
92 .build();
93 // Now we can build the trajectory from the BSP file.
94 // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
95 let traj_as_flown = Traj::from_bsp(
96 lro_frame,
97 MOON_J2000,
98 almanac.clone(),
99 sc_template,
100 5.seconds(),
101 Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
102 Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
103 Aberration::LT,
104 Some("LRO".to_string()),
105 )?;
106
107 println!("{traj_as_flown}");
108
109 // ====================== //
110 // === MODEL MATCHING === //
111 // ====================== //
112
113 // Set up the spacecraft dynamics.
114
115 // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
116 // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
117 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
118
119 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
120 // We're using the GRAIL JGGRX model.
121 let mut jggrx_meta = MetaFile {
122 uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
123 crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
124 };
125 // And let's download it if we don't have it yet.
126 jggrx_meta.process(true)?;
127
128 // Build the spherical harmonics.
129 // The harmonics must be computed in the body fixed frame.
130 // We're using the long term prediction of the Moon principal axes frame.
131 let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
132 let sph_harmonics = Harmonics::from_stor(
133 almanac.frame_info(moon_pa_frame)?,
134 HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
135 );
136
137 // Include the spherical harmonics into the orbital dynamics.
138 orbital_dyn.accel_models.push(sph_harmonics);
139
140 // We define the solar radiation pressure, using the default solar flux and accounting only
141 // for the eclipsing caused by the Earth and Moon.
142 // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
143 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
144
145 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
146 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
147 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
148
149 println!("{dynamics}");
150
151 // Now we can build the propagator.
152 let setup = Propagator::default_dp78(dynamics.clone());
153
154 // For reference, let's build the trajectory with Nyx's models from that LRO state.
155 let (sim_final, traj_as_sim) = setup
156 .with(*traj_as_flown.first(), almanac.clone())
157 .until_epoch_with_traj(traj_as_flown.last().epoch())?;
158
159 println!("SIM INIT: {:x}", traj_as_flown.first());
160 println!("SIM FINAL: {sim_final:x}");
161 // Compute RIC difference between SIM and LRO ephem
162 let sim_lro_delta = sim_final
163 .orbit
164 .ric_difference(&traj_as_flown.last().orbit)?;
165 println!("{traj_as_sim}");
166 println!(
167 "SIM v LRO - RIC Position (m): {:.3}",
168 sim_lro_delta.radius_km * 1e3
169 );
170 println!(
171 "SIM v LRO - RIC Velocity (m/s): {:.3}",
172 sim_lro_delta.velocity_km_s * 1e3
173 );
174
175 traj_as_sim.ric_diff_to_parquet(
176 &traj_as_flown,
177 "./data/04_output/04_lro_sim_truth_error.parquet",
178 ExportCfg::default(),
179 )?;
180
181 // ==================== //
182 // === OD SIMULATOR === //
183 // ==================== //
184
185 // After quite some time trying to exactly match the model, we still end up with an oscillatory difference on the order of 150 meters between the propagated state
186 // and the truth LRO state.
187
188 // Therefore, we will actually run an estimation from a dispersed LRO state.
189 // The sc_seed is the true LRO state from the BSP.
190 let sc_seed = *traj_as_flown.first();
191
192 // Load the Deep Space Network ground stations.
193 // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
194 let ground_station_file: PathBuf = [
195 env!("CARGO_MANIFEST_DIR"),
196 "examples",
197 "04_lro_od",
198 "dsn-network.yaml",
199 ]
200 .iter()
201 .collect();
202
203 let devices = GroundStation::load_named(ground_station_file)?;
204
205 let mut proc_devices = devices.clone();
206
207 // Increase the noise in the devices to accept more measurements.
208 for gs in proc_devices.values_mut() {
209 if let Some(noise) = &mut gs
210 .stochastic_noises
211 .as_mut()
212 .unwrap()
213 .get_mut(&MeasurementType::Range)
214 {
215 *noise.white_noise.as_mut().unwrap() *= 3.0;
216 }
217 }
218
219 // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
220 // Nyx can build a tracking schedule for you based on the first station with access.
221 let trkconfg_yaml: PathBuf = [
222 env!("CARGO_MANIFEST_DIR"),
223 "examples",
224 "04_lro_od",
225 "tracking-cfg.yaml",
226 ]
227 .iter()
228 .collect();
229
230 let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
231
232 // Build the tracking arc simulation to generate a "standard measurement".
233 let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
234 devices.clone(),
235 traj_as_flown.clone(),
236 configs,
237 123, // Set a seed for reproducibility
238 )?;
239
240 trk.build_schedule(almanac.clone())?;
241 let arc = trk.generate_measurements(almanac.clone())?;
242 // Save the simulated tracking data
243 arc.to_parquet_simple("./data/04_output/04_lro_simulated_tracking.parquet")?;
244
245 // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
246 println!("{arc}");
247
248 // Now that we have simulated measurements, we'll run the orbit determination.
249
250 // ===================== //
251 // === OD ESTIMATION === //
252 // ===================== //
253
254 let sc = SpacecraftUncertainty::builder()
255 .nominal(sc_seed)
256 .frame(LocalFrame::RIC)
257 .x_km(0.5)
258 .y_km(0.5)
259 .z_km(0.5)
260 .vx_km_s(5e-3)
261 .vy_km_s(5e-3)
262 .vz_km_s(5e-3)
263 .build();
264
265 // Build the filter initial estimate, which we will reuse in the filter.
266 let mut initial_estimate = sc.to_estimate()?;
267 initial_estimate.covar *= 3.0;
268
269 println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
270
271 // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
272 let process_noise = ProcessNoise3D::from_velocity_km_s(
273 &[1e-10, 1e-10, 1e-10],
274 1 * Unit::Hour,
275 10 * Unit::Minute,
276 None,
277 );
278
279 println!("{process_noise}");
280
281 // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
282 let odp = SpacecraftKalmanOD::new(
283 setup,
284 KalmanVariant::ReferenceUpdate,
285 Some(ResidRejectCrit::default()),
286 proc_devices,
287 almanac.clone(),
288 )
289 .with_process_noise(process_noise);
290
291 let od_sol = odp.process_arc(initial_estimate, &arc)?;
292
293 let final_est = od_sol.estimates.last().unwrap();
294
295 println!("{final_est}");
296
297 let ric_err = traj_as_flown
298 .at(final_est.epoch())?
299 .orbit
300 .ric_difference(&final_est.orbital_state())?;
301 println!("== RIC at end ==");
302 println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
303 println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
304
305 println!(
306 "Num residuals rejected: #{}",
307 od_sol.rejected_residuals().len()
308 );
309 println!(
310 "Percentage within +/-3: {}",
311 od_sol.residual_ratio_within_threshold(3.0).unwrap()
312 );
313 println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
314
315 od_sol.to_parquet(
316 "./data/04_output/04_lro_od_results.parquet",
317 ExportCfg::default(),
318 )?;
319
320 // Create the ephemeris
321 let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
322 let ephem_start = ephem.start_epoch().unwrap();
323 let ephem_end = ephem.end_epoch().unwrap();
324 // Check that the covariance is PSD throughout the ephemeris by interpolating it.
325 for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
326 ephem
327 .covar_at(
328 epoch,
329 anise::ephemerides::ephemeris::LocalFrame::RIC,
330 &almanac,
331 )
332 .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
333 }
334 // Export as BSP!
335 ephem
336 .write_spice_bsp(-85, "./data/04_output/04_lro_rebuilt.bsp", None)
337 .expect("could not built BSP");
338 let new_almanac = Almanac::default()
339 .load("./data/04_output/04_lro_rebuilt.bsp")
340 .unwrap();
341 new_almanac.describe(None, None, None, None, None, None, None, None);
342 let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
343
344 assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
345 assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
346
347 // In our case, we have the truth trajectory from NASA.
348 // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
349 // Export the OD trajectory first.
350 let od_trajectory = od_sol.to_traj()?;
351 // Build the RIC difference.
352 od_trajectory.ric_diff_to_parquet(
353 &traj_as_flown,
354 "./data/04_output/04_lro_od_truth_error.parquet",
355 ExportCfg::default(),
356 )?;
357
358 Ok(())
359}pub fn get_planetary_data_from_id(
&self,
id: i32,
) -> Result<PlanetaryData, PlanetaryDataError>
pub fn get_planetary_data_from_id( &self, id: i32, ) -> Result<PlanetaryData, PlanetaryDataError>
Returns the plantary from its ID, searching through all loaded planetary datasets in reverse order.
Examples found in repository?
35fn main() -> Result<(), Box<dyn Error>> {
36 pel::init();
37
38 // ====================== //
39 // === ALMANAC SET UP === //
40 // ====================== //
41
42 // Dynamics models require planetary constants and ephemerides to be defined.
43 // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45 let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
46 .iter()
47 .collect();
48
49 let meta = data_folder.join("lro-dynamics.dhall");
50
51 // Load this ephem in the general Almanac we're using for this analysis.
52 let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
53 .map_err(Box::new)?
54 .process(true)
55 .map_err(Box::new)?;
56
57 let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
58 moon_pc.mu_km3_s2 = 4902.74987;
59 almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
60
61 let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
62 earth.mu_km3_s2 = 398600.436;
63 almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
64
65 // Save this new kernel for reuse.
66 // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
67 almanac
68 .planetary_data
69 .values()
70 .next()
71 .unwrap()
72 .save_as(&data_folder.join("lro-specific.pca"), true)?;
73
74 // Lock the almanac (an Arc is a read only structure).
75 let almanac = Arc::new(almanac);
76
77 // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
78 // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
79 // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
80 // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
81 let lro_frame = Frame::from_ephem_j2000(-85);
82
83 // To build the trajectory we need to provide a spacecraft template.
84 let sc_template = Spacecraft::builder()
85 .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
86 .srp(SRPData {
87 // SRP configuration is arbitrary, but we will be estimating it anyway.
88 area_m2: 3.9 * 2.7,
89 coeff_reflectivity: 0.96,
90 })
91 .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
92 .build();
93 // Now we can build the trajectory from the BSP file.
94 // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
95 let traj_as_flown = Traj::from_bsp(
96 lro_frame,
97 MOON_J2000,
98 almanac.clone(),
99 sc_template,
100 5.seconds(),
101 Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
102 Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
103 Aberration::LT,
104 Some("LRO".to_string()),
105 )?;
106
107 println!("{traj_as_flown}");
108
109 // ====================== //
110 // === MODEL MATCHING === //
111 // ====================== //
112
113 // Set up the spacecraft dynamics.
114
115 // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
116 // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
117 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
118
119 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
120 // We're using the GRAIL JGGRX model.
121 let mut jggrx_meta = MetaFile {
122 uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
123 crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
124 };
125 // And let's download it if we don't have it yet.
126 jggrx_meta.process(true)?;
127
128 // Build the spherical harmonics.
129 // The harmonics must be computed in the body fixed frame.
130 // We're using the long term prediction of the Moon principal axes frame.
131 let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
132 let sph_harmonics = Harmonics::from_stor(
133 almanac.frame_info(moon_pa_frame)?,
134 HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
135 );
136
137 // Include the spherical harmonics into the orbital dynamics.
138 orbital_dyn.accel_models.push(sph_harmonics);
139
140 // We define the solar radiation pressure, using the default solar flux and accounting only
141 // for the eclipsing caused by the Earth and Moon.
142 // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
143 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
144
145 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
146 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
147 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
148
149 println!("{dynamics}");
150
151 // Now we can build the propagator.
152 let setup = Propagator::default_dp78(dynamics.clone());
153
154 // For reference, let's build the trajectory with Nyx's models from that LRO state.
155 let (sim_final, traj_as_sim) = setup
156 .with(*traj_as_flown.first(), almanac.clone())
157 .until_epoch_with_traj(traj_as_flown.last().epoch())?;
158
159 println!("SIM INIT: {:x}", traj_as_flown.first());
160 println!("SIM FINAL: {sim_final:x}");
161 // Compute RIC difference between SIM and LRO ephem
162 let sim_lro_delta = sim_final
163 .orbit
164 .ric_difference(&traj_as_flown.last().orbit)?;
165 println!("{traj_as_sim}");
166 println!(
167 "SIM v LRO - RIC Position (m): {:.3}",
168 sim_lro_delta.radius_km * 1e3
169 );
170 println!(
171 "SIM v LRO - RIC Velocity (m/s): {:.3}",
172 sim_lro_delta.velocity_km_s * 1e3
173 );
174
175 traj_as_sim.ric_diff_to_parquet(
176 &traj_as_flown,
177 "./data/04_output/04_lro_sim_truth_error.parquet",
178 ExportCfg::default(),
179 )?;
180
181 // ==================== //
182 // === OD SIMULATOR === //
183 // ==================== //
184
185 // After quite some time trying to exactly match the model, we still end up with an oscillatory difference on the order of 150 meters between the propagated state
186 // and the truth LRO state.
187
188 // Therefore, we will actually run an estimation from a dispersed LRO state.
189 // The sc_seed is the true LRO state from the BSP.
190 let sc_seed = *traj_as_flown.first();
191
192 // Load the Deep Space Network ground stations.
193 // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
194 let ground_station_file: PathBuf = [
195 env!("CARGO_MANIFEST_DIR"),
196 "examples",
197 "04_lro_od",
198 "dsn-network.yaml",
199 ]
200 .iter()
201 .collect();
202
203 let devices = GroundStation::load_named(ground_station_file)?;
204
205 let mut proc_devices = devices.clone();
206
207 // Increase the noise in the devices to accept more measurements.
208 for gs in proc_devices.values_mut() {
209 if let Some(noise) = &mut gs
210 .stochastic_noises
211 .as_mut()
212 .unwrap()
213 .get_mut(&MeasurementType::Range)
214 {
215 *noise.white_noise.as_mut().unwrap() *= 3.0;
216 }
217 }
218
219 // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
220 // Nyx can build a tracking schedule for you based on the first station with access.
221 let trkconfg_yaml: PathBuf = [
222 env!("CARGO_MANIFEST_DIR"),
223 "examples",
224 "04_lro_od",
225 "tracking-cfg.yaml",
226 ]
227 .iter()
228 .collect();
229
230 let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
231
232 // Build the tracking arc simulation to generate a "standard measurement".
233 let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
234 devices.clone(),
235 traj_as_flown.clone(),
236 configs,
237 123, // Set a seed for reproducibility
238 )?;
239
240 trk.build_schedule(almanac.clone())?;
241 let arc = trk.generate_measurements(almanac.clone())?;
242 // Save the simulated tracking data
243 arc.to_parquet_simple("./data/04_output/04_lro_simulated_tracking.parquet")?;
244
245 // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
246 println!("{arc}");
247
248 // Now that we have simulated measurements, we'll run the orbit determination.
249
250 // ===================== //
251 // === OD ESTIMATION === //
252 // ===================== //
253
254 let sc = SpacecraftUncertainty::builder()
255 .nominal(sc_seed)
256 .frame(LocalFrame::RIC)
257 .x_km(0.5)
258 .y_km(0.5)
259 .z_km(0.5)
260 .vx_km_s(5e-3)
261 .vy_km_s(5e-3)
262 .vz_km_s(5e-3)
263 .build();
264
265 // Build the filter initial estimate, which we will reuse in the filter.
266 let mut initial_estimate = sc.to_estimate()?;
267 initial_estimate.covar *= 3.0;
268
269 println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
270
271 // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
272 let process_noise = ProcessNoise3D::from_velocity_km_s(
273 &[1e-10, 1e-10, 1e-10],
274 1 * Unit::Hour,
275 10 * Unit::Minute,
276 None,
277 );
278
279 println!("{process_noise}");
280
281 // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
282 let odp = SpacecraftKalmanOD::new(
283 setup,
284 KalmanVariant::ReferenceUpdate,
285 Some(ResidRejectCrit::default()),
286 proc_devices,
287 almanac.clone(),
288 )
289 .with_process_noise(process_noise);
290
291 let od_sol = odp.process_arc(initial_estimate, &arc)?;
292
293 let final_est = od_sol.estimates.last().unwrap();
294
295 println!("{final_est}");
296
297 let ric_err = traj_as_flown
298 .at(final_est.epoch())?
299 .orbit
300 .ric_difference(&final_est.orbital_state())?;
301 println!("== RIC at end ==");
302 println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
303 println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
304
305 println!(
306 "Num residuals rejected: #{}",
307 od_sol.rejected_residuals().len()
308 );
309 println!(
310 "Percentage within +/-3: {}",
311 od_sol.residual_ratio_within_threshold(3.0).unwrap()
312 );
313 println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
314
315 od_sol.to_parquet(
316 "./data/04_output/04_lro_od_results.parquet",
317 ExportCfg::default(),
318 )?;
319
320 // Create the ephemeris
321 let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
322 let ephem_start = ephem.start_epoch().unwrap();
323 let ephem_end = ephem.end_epoch().unwrap();
324 // Check that the covariance is PSD throughout the ephemeris by interpolating it.
325 for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
326 ephem
327 .covar_at(
328 epoch,
329 anise::ephemerides::ephemeris::LocalFrame::RIC,
330 &almanac,
331 )
332 .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
333 }
334 // Export as BSP!
335 ephem
336 .write_spice_bsp(-85, "./data/04_output/04_lro_rebuilt.bsp", None)
337 .expect("could not built BSP");
338 let new_almanac = Almanac::default()
339 .load("./data/04_output/04_lro_rebuilt.bsp")
340 .unwrap();
341 new_almanac.describe(None, None, None, None, None, None, None, None);
342 let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
343
344 assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
345 assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
346
347 // In our case, we have the truth trajectory from NASA.
348 // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
349 // Export the OD trajectory first.
350 let od_trajectory = od_sol.to_traj()?;
351 // Build the RIC difference.
352 od_trajectory.ric_diff_to_parquet(
353 &traj_as_flown,
354 "./data/04_output/04_lro_od_truth_error.parquet",
355 ExportCfg::default(),
356 )?;
357
358 Ok(())
359}pub fn set_planetary_data_from_id(
&mut self,
id: i32,
planetary_data: PlanetaryData,
) -> Result<(), PlanetaryDataError>
pub fn set_planetary_data_from_id( &mut self, id: i32, planetary_data: PlanetaryData, ) -> Result<(), PlanetaryDataError>
Returns the plantary from its ID, searching through all loaded planetary datasets in reverse order.
Examples found in repository?
35fn main() -> Result<(), Box<dyn Error>> {
36 pel::init();
37
38 // ====================== //
39 // === ALMANAC SET UP === //
40 // ====================== //
41
42 // Dynamics models require planetary constants and ephemerides to be defined.
43 // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45 let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
46 .iter()
47 .collect();
48
49 let meta = data_folder.join("lro-dynamics.dhall");
50
51 // Load this ephem in the general Almanac we're using for this analysis.
52 let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
53 .map_err(Box::new)?
54 .process(true)
55 .map_err(Box::new)?;
56
57 let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
58 moon_pc.mu_km3_s2 = 4902.74987;
59 almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
60
61 let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
62 earth.mu_km3_s2 = 398600.436;
63 almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
64
65 // Save this new kernel for reuse.
66 // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
67 almanac
68 .planetary_data
69 .values()
70 .next()
71 .unwrap()
72 .save_as(&data_folder.join("lro-specific.pca"), true)?;
73
74 // Lock the almanac (an Arc is a read only structure).
75 let almanac = Arc::new(almanac);
76
77 // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
78 // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
79 // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
80 // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
81 let lro_frame = Frame::from_ephem_j2000(-85);
82
83 // To build the trajectory we need to provide a spacecraft template.
84 let sc_template = Spacecraft::builder()
85 .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
86 .srp(SRPData {
87 // SRP configuration is arbitrary, but we will be estimating it anyway.
88 area_m2: 3.9 * 2.7,
89 coeff_reflectivity: 0.96,
90 })
91 .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
92 .build();
93 // Now we can build the trajectory from the BSP file.
94 // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
95 let traj_as_flown = Traj::from_bsp(
96 lro_frame,
97 MOON_J2000,
98 almanac.clone(),
99 sc_template,
100 5.seconds(),
101 Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
102 Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
103 Aberration::LT,
104 Some("LRO".to_string()),
105 )?;
106
107 println!("{traj_as_flown}");
108
109 // ====================== //
110 // === MODEL MATCHING === //
111 // ====================== //
112
113 // Set up the spacecraft dynamics.
114
115 // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
116 // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
117 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
118
119 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
120 // We're using the GRAIL JGGRX model.
121 let mut jggrx_meta = MetaFile {
122 uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
123 crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
124 };
125 // And let's download it if we don't have it yet.
126 jggrx_meta.process(true)?;
127
128 // Build the spherical harmonics.
129 // The harmonics must be computed in the body fixed frame.
130 // We're using the long term prediction of the Moon principal axes frame.
131 let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
132 let sph_harmonics = Harmonics::from_stor(
133 almanac.frame_info(moon_pa_frame)?,
134 HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
135 );
136
137 // Include the spherical harmonics into the orbital dynamics.
138 orbital_dyn.accel_models.push(sph_harmonics);
139
140 // We define the solar radiation pressure, using the default solar flux and accounting only
141 // for the eclipsing caused by the Earth and Moon.
142 // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
143 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
144
145 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
146 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
147 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
148
149 println!("{dynamics}");
150
151 // Now we can build the propagator.
152 let setup = Propagator::default_dp78(dynamics.clone());
153
154 // For reference, let's build the trajectory with Nyx's models from that LRO state.
155 let (sim_final, traj_as_sim) = setup
156 .with(*traj_as_flown.first(), almanac.clone())
157 .until_epoch_with_traj(traj_as_flown.last().epoch())?;
158
159 println!("SIM INIT: {:x}", traj_as_flown.first());
160 println!("SIM FINAL: {sim_final:x}");
161 // Compute RIC difference between SIM and LRO ephem
162 let sim_lro_delta = sim_final
163 .orbit
164 .ric_difference(&traj_as_flown.last().orbit)?;
165 println!("{traj_as_sim}");
166 println!(
167 "SIM v LRO - RIC Position (m): {:.3}",
168 sim_lro_delta.radius_km * 1e3
169 );
170 println!(
171 "SIM v LRO - RIC Velocity (m/s): {:.3}",
172 sim_lro_delta.velocity_km_s * 1e3
173 );
174
175 traj_as_sim.ric_diff_to_parquet(
176 &traj_as_flown,
177 "./data/04_output/04_lro_sim_truth_error.parquet",
178 ExportCfg::default(),
179 )?;
180
181 // ==================== //
182 // === OD SIMULATOR === //
183 // ==================== //
184
185 // After quite some time trying to exactly match the model, we still end up with an oscillatory difference on the order of 150 meters between the propagated state
186 // and the truth LRO state.
187
188 // Therefore, we will actually run an estimation from a dispersed LRO state.
189 // The sc_seed is the true LRO state from the BSP.
190 let sc_seed = *traj_as_flown.first();
191
192 // Load the Deep Space Network ground stations.
193 // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
194 let ground_station_file: PathBuf = [
195 env!("CARGO_MANIFEST_DIR"),
196 "examples",
197 "04_lro_od",
198 "dsn-network.yaml",
199 ]
200 .iter()
201 .collect();
202
203 let devices = GroundStation::load_named(ground_station_file)?;
204
205 let mut proc_devices = devices.clone();
206
207 // Increase the noise in the devices to accept more measurements.
208 for gs in proc_devices.values_mut() {
209 if let Some(noise) = &mut gs
210 .stochastic_noises
211 .as_mut()
212 .unwrap()
213 .get_mut(&MeasurementType::Range)
214 {
215 *noise.white_noise.as_mut().unwrap() *= 3.0;
216 }
217 }
218
219 // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
220 // Nyx can build a tracking schedule for you based on the first station with access.
221 let trkconfg_yaml: PathBuf = [
222 env!("CARGO_MANIFEST_DIR"),
223 "examples",
224 "04_lro_od",
225 "tracking-cfg.yaml",
226 ]
227 .iter()
228 .collect();
229
230 let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
231
232 // Build the tracking arc simulation to generate a "standard measurement".
233 let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
234 devices.clone(),
235 traj_as_flown.clone(),
236 configs,
237 123, // Set a seed for reproducibility
238 )?;
239
240 trk.build_schedule(almanac.clone())?;
241 let arc = trk.generate_measurements(almanac.clone())?;
242 // Save the simulated tracking data
243 arc.to_parquet_simple("./data/04_output/04_lro_simulated_tracking.parquet")?;
244
245 // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
246 println!("{arc}");
247
248 // Now that we have simulated measurements, we'll run the orbit determination.
249
250 // ===================== //
251 // === OD ESTIMATION === //
252 // ===================== //
253
254 let sc = SpacecraftUncertainty::builder()
255 .nominal(sc_seed)
256 .frame(LocalFrame::RIC)
257 .x_km(0.5)
258 .y_km(0.5)
259 .z_km(0.5)
260 .vx_km_s(5e-3)
261 .vy_km_s(5e-3)
262 .vz_km_s(5e-3)
263 .build();
264
265 // Build the filter initial estimate, which we will reuse in the filter.
266 let mut initial_estimate = sc.to_estimate()?;
267 initial_estimate.covar *= 3.0;
268
269 println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
270
271 // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
272 let process_noise = ProcessNoise3D::from_velocity_km_s(
273 &[1e-10, 1e-10, 1e-10],
274 1 * Unit::Hour,
275 10 * Unit::Minute,
276 None,
277 );
278
279 println!("{process_noise}");
280
281 // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
282 let odp = SpacecraftKalmanOD::new(
283 setup,
284 KalmanVariant::ReferenceUpdate,
285 Some(ResidRejectCrit::default()),
286 proc_devices,
287 almanac.clone(),
288 )
289 .with_process_noise(process_noise);
290
291 let od_sol = odp.process_arc(initial_estimate, &arc)?;
292
293 let final_est = od_sol.estimates.last().unwrap();
294
295 println!("{final_est}");
296
297 let ric_err = traj_as_flown
298 .at(final_est.epoch())?
299 .orbit
300 .ric_difference(&final_est.orbital_state())?;
301 println!("== RIC at end ==");
302 println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
303 println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
304
305 println!(
306 "Num residuals rejected: #{}",
307 od_sol.rejected_residuals().len()
308 );
309 println!(
310 "Percentage within +/-3: {}",
311 od_sol.residual_ratio_within_threshold(3.0).unwrap()
312 );
313 println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
314
315 od_sol.to_parquet(
316 "./data/04_output/04_lro_od_results.parquet",
317 ExportCfg::default(),
318 )?;
319
320 // Create the ephemeris
321 let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
322 let ephem_start = ephem.start_epoch().unwrap();
323 let ephem_end = ephem.end_epoch().unwrap();
324 // Check that the covariance is PSD throughout the ephemeris by interpolating it.
325 for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
326 ephem
327 .covar_at(
328 epoch,
329 anise::ephemerides::ephemeris::LocalFrame::RIC,
330 &almanac,
331 )
332 .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
333 }
334 // Export as BSP!
335 ephem
336 .write_spice_bsp(-85, "./data/04_output/04_lro_rebuilt.bsp", None)
337 .expect("could not built BSP");
338 let new_almanac = Almanac::default()
339 .load("./data/04_output/04_lro_rebuilt.bsp")
340 .unwrap();
341 new_almanac.describe(None, None, None, None, None, None, None, None);
342 let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
343
344 assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
345 assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
346
347 // In our case, we have the truth trajectory from NASA.
348 // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
349 // Export the OD trajectory first.
350 let od_trajectory = od_sol.to_traj()?;
351 // Build the RIC difference.
352 od_trajectory.ric_diff_to_parquet(
353 &traj_as_flown,
354 "./data/04_output/04_lro_od_truth_error.parquet",
355 ExportCfg::default(),
356 )?;
357
358 Ok(())
359}pub fn with_planetary_data(
self,
planetary_data: DataSet<PlanetaryData>,
) -> Almanac
pub fn with_planetary_data( self, planetary_data: DataSet<PlanetaryData>, ) -> Almanac
Loads the provided planetary data.
pub fn with_planetary_data_as(
self,
planetary_data: DataSet<PlanetaryData>,
alias: Option<String>,
) -> Almanac
pub fn with_planetary_data_as( self, planetary_data: DataSet<PlanetaryData>, alias: Option<String>, ) -> Almanac
Loads the provided planetary data.
§impl Almanac
impl Almanac
pub fn sun_angle_deg(
&self,
target_id: i32,
observer_id: i32,
epoch: Epoch,
ab_corr: Option<Aberration>,
) -> Result<f64, EphemerisError>
pub fn sun_angle_deg( &self, target_id: i32, observer_id: i32, epoch: Epoch, ab_corr: Option<Aberration>, ) -> Result<f64, EphemerisError>
Returns the angular separation (between 0 and 180 degrees) between the observer and the Sun, and the observer and the target body ID. This is formally known as the “solar elongation”. This computes the Sun Probe Earth angle (SPE) if the probe is in a loaded SPK, its ID is the “observer_id”, and the target is set to its central body.
§Geometry
If the SPE is greater than 90 degrees, then the celestial object below the probe is in sunlight.
This angle determines the illumination phase of the target as seen by the observer:
- ~0° (Conjunction): The Target is in the same direction as the Sun. The observer sees the unlit side (“New Moon”).
- ~180° (Opposition): The Target is in the opposite direction of the Sun. The observer sees the fully lit side (“Full Moon”).
- > 90°: The observer is generally on the “day” side of the target.
§Sunrise at nadir
Sun
| \
| \
| \
Obs. -- Target§Sun high at nadir
Sun
\
\ __ θ > 90
\ \
Obs. ---------- Target§Sunset at nadir
Sun
/
/ __ θ < 90
/ /
Obs. -- Target§Algorithm
- Compute the position of the Sun as seen from the observer
- Compute the position of the target as seen from the observer
- Return the arccosine of the dot product of the norms of these vectors.
:type target_id: int :type observer_id: int :type epoch: Epoch :type ab_corr: Aberration :rtype: float
pub fn sun_angle_deg_from_frame(
&self,
target: Frame,
observer: Frame,
epoch: Epoch,
ab_corr: Option<Aberration>,
) -> Result<f64, EphemerisError>
pub fn sun_angle_deg_from_frame( &self, target: Frame, observer: Frame, epoch: Epoch, ab_corr: Option<Aberration>, ) -> Result<f64, EphemerisError>
Convenience function that calls sun_angle_deg with the provided frames instead of the ephemeris ID.
:type target: Frame :type observer: Frame :type epoch: Epoch :type ab_corr: Aberration :rtype: float
§impl Almanac
impl Almanac
pub fn from_spk(spk: DAF<SPKSummaryRecord>) -> Almanac
pub fn with_spk(self, spk: DAF<SPKSummaryRecord>) -> Almanac
pub fn with_spk(self, spk: DAF<SPKSummaryRecord>) -> Almanac
Loads a new SPK file into a new context, using the system time as the alias. If the time is not availble, then 0 TAI is used. This new context is needed to satisfy the unloading of files. In fact, to unload a file, simply let the newly loaded context drop out of scope and Rust will clean it up.
pub fn with_spk_as(
self,
spk: DAF<SPKSummaryRecord>,
alias: Option<String>,
) -> Almanac
pub fn with_spk_as( self, spk: DAF<SPKSummaryRecord>, alias: Option<String>, ) -> Almanac
Loads a new SPK file into a new context, naming it with the provided alias, or the current system time if no alias is provided. To unload a file, call spk_unload.
pub fn spk_unload(&mut self, alias: &str) -> Result<(), EphemerisError>
pub fn spk_unload(&mut self, alias: &str) -> Result<(), EphemerisError>
Unloads the SPK with the provided alias. WARNING: This causes the order of the loaded files to be perturbed, which may be an issue if several SPKs with the same IDs are loaded.
§impl Almanac
impl Almanac
pub fn num_loaded_spk(&self) -> usize
pub fn spk_summary_from_name_at_epoch(
&self,
name: &str,
epoch: Epoch,
) -> Result<(&SPKSummaryRecord, usize, Option<usize>, usize), EphemerisError>
pub fn spk_summary_from_name_at_epoch( &self, name: &str, epoch: Epoch, ) -> Result<(&SPKSummaryRecord, usize, Option<usize>, usize), EphemerisError>
Returns the summary given the name of the summary record if that summary has data defined at the requested epoch and the SPK where this name was found to be valid at that epoch.
pub fn spk_summary_at_epoch(
&self,
id: i32,
epoch: Epoch,
) -> Result<(&SPKSummaryRecord, usize, Option<usize>, usize), EphemerisError>
pub fn spk_summary_at_epoch( &self, id: i32, epoch: Epoch, ) -> Result<(&SPKSummaryRecord, usize, Option<usize>, usize), EphemerisError>
Returns the summary given the name of the summary record if that summary has data defined at the requested epoch
§impl Almanac
impl Almanac
pub fn spk_summaries(
&self,
id: i32,
) -> Result<Vec<SPKSummaryRecord>, EphemerisError>
pub fn spk_summaries( &self, id: i32, ) -> Result<Vec<SPKSummaryRecord>, EphemerisError>
Returns a vector of the summaries whose ID matches the desired id, in the order in which they will be used, i.e. in reverse loading order.
§Warning
This function performs a memory allocation.
:type id: int :rtype: typing.List
pub fn spk_domain(&self, id: i32) -> Result<(Epoch, Epoch), EphemerisError>
pub fn spk_domain(&self, id: i32) -> Result<(Epoch, Epoch), EphemerisError>
Returns the applicable domain of the request id, i.e. start and end epoch that the provided id has loaded data.
:type id: int :rtype: typing.Tuple
Examples found in repository?
26fn main() -> Result<(), Box<dyn Error>> {
27 pel::init();
28 // Dynamics models require planetary constants and ephemerides to be defined.
29 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
30 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
31
32 // Download the regularly update of the James Webb Space Telescope reconstucted (or definitive) ephemeris.
33 // Refer to https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/aareadme.txt for details.
34 let mut latest_jwst_ephem = MetaFile {
35 uri: "https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/jwst_rec.bsp".to_string(),
36 crc32: None,
37 };
38 latest_jwst_ephem.process(true)?;
39
40 // Load this ephem in the general Almanac we're using for this analysis.
41 let almanac = Arc::new(
42 MetaAlmanac::latest()
43 .map_err(Box::new)?
44 .load_from_metafile(latest_jwst_ephem, true)?,
45 );
46
47 // By loading this ephemeris file in the ANISE GUI or ANISE CLI, we can find the NAIF ID of the JWST
48 // in the BSP. We need this ID in order to query the ephemeris.
49 const JWST_NAIF_ID: i32 = -170;
50 // Let's build a frame in the J2000 orientation centered on the JWST.
51 const JWST_J2000: Frame = Frame::from_ephem_j2000(JWST_NAIF_ID);
52
53 // Since the ephemeris file is updated regularly, we'll just grab the latest state in the ephem.
54 let (earliest_epoch, latest_epoch) = almanac.spk_domain(JWST_NAIF_ID)?;
55 println!("JWST defined from {earliest_epoch} to {latest_epoch}");
56 // Fetch the state, printing it in the Earth J2000 frame.
57 let jwst_orbit = almanac.transform(JWST_J2000, EARTH_J2000, latest_epoch, None)?;
58 println!("{jwst_orbit:x}");
59
60 // Build the spacecraft
61 // SRP area assumed to be the full sunshield and mass if 6200.0 kg, c.f. https://webb.nasa.gov/content/about/faqs/facts.html
62 // SRP Coefficient of reflectivity assumed to be that of Kapton, i.e. 2 - 0.44 = 1.56, table 1 from https://amostech.com/TechnicalPapers/2018/Poster/Bengtson.pdf
63 let jwst = Spacecraft::builder()
64 .orbit(jwst_orbit)
65 .srp(SRPData {
66 area_m2: 21.197 * 14.162,
67 coeff_reflectivity: 1.56,
68 })
69 .mass(Mass::from_dry_mass(6200.0))
70 .build();
71
72 // Build up the spacecraft uncertainty builder.
73 // We can use the spacecraft uncertainty structure to build this up.
74 // We start by specifying the nominal state (as defined above), then the uncertainty in position and velocity
75 // in the RIC frame. We could also specify the Cr, Cd, and mass uncertainties, but these aren't accounted for until
76 // Nyx can also estimate the deviation of the spacecraft parameters.
77 let jwst_uncertainty = SpacecraftUncertainty::builder()
78 .nominal(jwst)
79 .frame(LocalFrame::RIC)
80 .x_km(0.5)
81 .y_km(0.3)
82 .z_km(1.5)
83 .vx_km_s(1e-4)
84 .vy_km_s(0.6e-3)
85 .vz_km_s(3e-3)
86 .build();
87
88 println!("{jwst_uncertainty}");
89
90 // Build the Kalman filter estimate.
91 // Note that we could have used the KfEstimate structure directly (as seen throughout the OD integration tests)
92 // but this approach requires quite a bit more boilerplate code.
93 let jwst_estimate = jwst_uncertainty.to_estimate()?;
94
95 // Set up the spacecraft dynamics.
96 // We'll use the point masses of the Earth, Sun, Jupiter (barycenter, because it's in the DE440), and the Moon.
97 // We'll also enable solar radiation pressure since the James Webb has a huge and highly reflective sun shield.
98
99 let orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN, JUPITER_BARYCENTER]);
100 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
101
102 // Finalize setting up the dynamics.
103 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
104
105 // Build the propagator set up to use for the whole analysis.
106 let setup = Propagator::default(dynamics);
107
108 // All of the analysis will use this duration.
109 let prediction_duration = 6.5 * Unit::Day;
110
111 // === Covariance mapping ===
112 // For the covariance mapping / prediction, we'll use the common orbit determination approach.
113 // This is done by setting up a spacecraft Kalman filter OD process, and predicting for the analysis duration.
114
115 // Build the propagation instance for the OD process.
116 let odp = SpacecraftKalmanOD::new(
117 setup.clone(),
118 KalmanVariant::DeviationTracking,
119 None,
120 BTreeMap::new(),
121 almanac.clone(),
122 );
123
124 // The prediction step is 1 minute by default, configured in the OD process, i.e. how often we want to know the covariance.
125 assert_eq!(odp.max_step, 1_i64.minutes());
126 // Finally, predict, and export the trajectory with covariance to a parquet file.
127 let od_sol = odp.predict_for(jwst_estimate, prediction_duration)?;
128 od_sol.to_parquet("./02_jwst_covar_map.parquet", ExportCfg::default())?;
129
130 // === Monte Carlo framework ===
131 // Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
132
133 let my_mc = MonteCarlo::new(
134 jwst, // Nominal state
135 jwst_estimate.to_random_variable()?,
136 "02_jwst".to_string(), // Scenario name
137 None, // No specific seed specified, so one will be drawn from the computer's entropy.
138 );
139
140 let num_runs = 5_000;
141 let rslts = my_mc.run_until_epoch(
142 setup,
143 almanac.clone(),
144 jwst.epoch() + prediction_duration,
145 num_runs,
146 );
147
148 assert_eq!(rslts.runs.len(), num_runs);
149 // Finally, export these results, computing the eclipse percentage for all of these results.
150
151 rslts.to_parquet("02_jwst_monte_carlo.parquet", ExportCfg::default())?;
152
153 Ok(())
154}More examples
35fn main() -> Result<(), Box<dyn Error>> {
36 pel::init();
37
38 // ====================== //
39 // === ALMANAC SET UP === //
40 // ====================== //
41
42 // Dynamics models require planetary constants and ephemerides to be defined.
43 // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45 let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
46 .iter()
47 .collect();
48
49 let meta = data_folder.join("lro-dynamics.dhall");
50
51 // Load this ephem in the general Almanac we're using for this analysis.
52 let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
53 .map_err(Box::new)?
54 .process(true)
55 .map_err(Box::new)?;
56
57 let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
58 moon_pc.mu_km3_s2 = 4902.74987;
59 almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
60
61 let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
62 earth.mu_km3_s2 = 398600.436;
63 almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
64
65 // Save this new kernel for reuse.
66 // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
67 almanac
68 .planetary_data
69 .values()
70 .next()
71 .unwrap()
72 .save_as(&data_folder.join("lro-specific.pca"), true)?;
73
74 // Lock the almanac (an Arc is a read only structure).
75 let almanac = Arc::new(almanac);
76
77 // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
78 // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
79 // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
80 // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
81 let lro_frame = Frame::from_ephem_j2000(-85);
82
83 // To build the trajectory we need to provide a spacecraft template.
84 let sc_template = Spacecraft::builder()
85 .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
86 .srp(SRPData {
87 // SRP configuration is arbitrary, but we will be estimating it anyway.
88 area_m2: 3.9 * 2.7,
89 coeff_reflectivity: 0.96,
90 })
91 .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
92 .build();
93 // Now we can build the trajectory from the BSP file.
94 // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
95 let traj_as_flown = Traj::from_bsp(
96 lro_frame,
97 MOON_J2000,
98 almanac.clone(),
99 sc_template,
100 5.seconds(),
101 Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
102 Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
103 Aberration::LT,
104 Some("LRO".to_string()),
105 )?;
106
107 println!("{traj_as_flown}");
108
109 // ====================== //
110 // === MODEL MATCHING === //
111 // ====================== //
112
113 // Set up the spacecraft dynamics.
114
115 // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
116 // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
117 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
118
119 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
120 // We're using the GRAIL JGGRX model.
121 let mut jggrx_meta = MetaFile {
122 uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
123 crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
124 };
125 // And let's download it if we don't have it yet.
126 jggrx_meta.process(true)?;
127
128 // Build the spherical harmonics.
129 // The harmonics must be computed in the body fixed frame.
130 // We're using the long term prediction of the Moon principal axes frame.
131 let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
132 let sph_harmonics = Harmonics::from_stor(
133 almanac.frame_info(moon_pa_frame)?,
134 HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
135 );
136
137 // Include the spherical harmonics into the orbital dynamics.
138 orbital_dyn.accel_models.push(sph_harmonics);
139
140 // We define the solar radiation pressure, using the default solar flux and accounting only
141 // for the eclipsing caused by the Earth and Moon.
142 // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
143 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
144
145 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
146 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
147 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
148
149 println!("{dynamics}");
150
151 // Now we can build the propagator.
152 let setup = Propagator::default_dp78(dynamics.clone());
153
154 // For reference, let's build the trajectory with Nyx's models from that LRO state.
155 let (sim_final, traj_as_sim) = setup
156 .with(*traj_as_flown.first(), almanac.clone())
157 .until_epoch_with_traj(traj_as_flown.last().epoch())?;
158
159 println!("SIM INIT: {:x}", traj_as_flown.first());
160 println!("SIM FINAL: {sim_final:x}");
161 // Compute RIC difference between SIM and LRO ephem
162 let sim_lro_delta = sim_final
163 .orbit
164 .ric_difference(&traj_as_flown.last().orbit)?;
165 println!("{traj_as_sim}");
166 println!(
167 "SIM v LRO - RIC Position (m): {:.3}",
168 sim_lro_delta.radius_km * 1e3
169 );
170 println!(
171 "SIM v LRO - RIC Velocity (m/s): {:.3}",
172 sim_lro_delta.velocity_km_s * 1e3
173 );
174
175 traj_as_sim.ric_diff_to_parquet(
176 &traj_as_flown,
177 "./data/04_output/04_lro_sim_truth_error.parquet",
178 ExportCfg::default(),
179 )?;
180
181 // ==================== //
182 // === OD SIMULATOR === //
183 // ==================== //
184
185 // After quite some time trying to exactly match the model, we still end up with an oscillatory difference on the order of 150 meters between the propagated state
186 // and the truth LRO state.
187
188 // Therefore, we will actually run an estimation from a dispersed LRO state.
189 // The sc_seed is the true LRO state from the BSP.
190 let sc_seed = *traj_as_flown.first();
191
192 // Load the Deep Space Network ground stations.
193 // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
194 let ground_station_file: PathBuf = [
195 env!("CARGO_MANIFEST_DIR"),
196 "examples",
197 "04_lro_od",
198 "dsn-network.yaml",
199 ]
200 .iter()
201 .collect();
202
203 let devices = GroundStation::load_named(ground_station_file)?;
204
205 let mut proc_devices = devices.clone();
206
207 // Increase the noise in the devices to accept more measurements.
208 for gs in proc_devices.values_mut() {
209 if let Some(noise) = &mut gs
210 .stochastic_noises
211 .as_mut()
212 .unwrap()
213 .get_mut(&MeasurementType::Range)
214 {
215 *noise.white_noise.as_mut().unwrap() *= 3.0;
216 }
217 }
218
219 // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
220 // Nyx can build a tracking schedule for you based on the first station with access.
221 let trkconfg_yaml: PathBuf = [
222 env!("CARGO_MANIFEST_DIR"),
223 "examples",
224 "04_lro_od",
225 "tracking-cfg.yaml",
226 ]
227 .iter()
228 .collect();
229
230 let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
231
232 // Build the tracking arc simulation to generate a "standard measurement".
233 let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
234 devices.clone(),
235 traj_as_flown.clone(),
236 configs,
237 123, // Set a seed for reproducibility
238 )?;
239
240 trk.build_schedule(almanac.clone())?;
241 let arc = trk.generate_measurements(almanac.clone())?;
242 // Save the simulated tracking data
243 arc.to_parquet_simple("./data/04_output/04_lro_simulated_tracking.parquet")?;
244
245 // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
246 println!("{arc}");
247
248 // Now that we have simulated measurements, we'll run the orbit determination.
249
250 // ===================== //
251 // === OD ESTIMATION === //
252 // ===================== //
253
254 let sc = SpacecraftUncertainty::builder()
255 .nominal(sc_seed)
256 .frame(LocalFrame::RIC)
257 .x_km(0.5)
258 .y_km(0.5)
259 .z_km(0.5)
260 .vx_km_s(5e-3)
261 .vy_km_s(5e-3)
262 .vz_km_s(5e-3)
263 .build();
264
265 // Build the filter initial estimate, which we will reuse in the filter.
266 let mut initial_estimate = sc.to_estimate()?;
267 initial_estimate.covar *= 3.0;
268
269 println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
270
271 // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
272 let process_noise = ProcessNoise3D::from_velocity_km_s(
273 &[1e-10, 1e-10, 1e-10],
274 1 * Unit::Hour,
275 10 * Unit::Minute,
276 None,
277 );
278
279 println!("{process_noise}");
280
281 // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
282 let odp = SpacecraftKalmanOD::new(
283 setup,
284 KalmanVariant::ReferenceUpdate,
285 Some(ResidRejectCrit::default()),
286 proc_devices,
287 almanac.clone(),
288 )
289 .with_process_noise(process_noise);
290
291 let od_sol = odp.process_arc(initial_estimate, &arc)?;
292
293 let final_est = od_sol.estimates.last().unwrap();
294
295 println!("{final_est}");
296
297 let ric_err = traj_as_flown
298 .at(final_est.epoch())?
299 .orbit
300 .ric_difference(&final_est.orbital_state())?;
301 println!("== RIC at end ==");
302 println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
303 println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
304
305 println!(
306 "Num residuals rejected: #{}",
307 od_sol.rejected_residuals().len()
308 );
309 println!(
310 "Percentage within +/-3: {}",
311 od_sol.residual_ratio_within_threshold(3.0).unwrap()
312 );
313 println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
314
315 od_sol.to_parquet(
316 "./data/04_output/04_lro_od_results.parquet",
317 ExportCfg::default(),
318 )?;
319
320 // Create the ephemeris
321 let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
322 let ephem_start = ephem.start_epoch().unwrap();
323 let ephem_end = ephem.end_epoch().unwrap();
324 // Check that the covariance is PSD throughout the ephemeris by interpolating it.
325 for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
326 ephem
327 .covar_at(
328 epoch,
329 anise::ephemerides::ephemeris::LocalFrame::RIC,
330 &almanac,
331 )
332 .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
333 }
334 // Export as BSP!
335 ephem
336 .write_spice_bsp(-85, "./data/04_output/04_lro_rebuilt.bsp", None)
337 .expect("could not built BSP");
338 let new_almanac = Almanac::default()
339 .load("./data/04_output/04_lro_rebuilt.bsp")
340 .unwrap();
341 new_almanac.describe(None, None, None, None, None, None, None, None);
342 let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
343
344 assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
345 assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
346
347 // In our case, we have the truth trajectory from NASA.
348 // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
349 // Export the OD trajectory first.
350 let od_trajectory = od_sol.to_traj()?;
351 // Build the RIC difference.
352 od_trajectory.ric_diff_to_parquet(
353 &traj_as_flown,
354 "./data/04_output/04_lro_od_truth_error.parquet",
355 ExportCfg::default(),
356 )?;
357
358 Ok(())
359}§impl Almanac
impl Almanac
pub fn transform(
&self,
target_frame: Frame,
observer_frame: Frame,
epoch: Epoch,
ab_corr: Option<Aberration>,
) -> Result<CartesianState, AlmanacError>
pub fn transform( &self, target_frame: Frame, observer_frame: Frame, epoch: Epoch, ab_corr: Option<Aberration>, ) -> Result<CartesianState, AlmanacError>
Returns the Cartesian state needed to transform the target_frame to the observer_frame.
§SPICE Compatibility
This function is the SPICE equivalent of spkezr: spkezr(TARGET_ID, EPOCH_TDB_S, ORIENTATION_ID, ABERRATION, OBSERVER_ID)
In ANISE, the TARGET_ID and ORIENTATION are provided in the first argument (TARGET_FRAME), as that frame includes BOTH
the target ID and the orientation of that target. The EPOCH_TDB_S is the epoch in the TDB time system, which is computed
in ANISE using Hifitime. THe ABERRATION is computed by providing the optional Aberration flag. Finally, the OBSERVER
argument is replaced by OBSERVER_FRAME: if the OBSERVER_FRAME argument has the same orientation as the TARGET_FRAME, then this call
will return exactly the same data as the spkerz SPICE call.
§Note
The units will be those of the underlying ephemeris data (typically km and km/s)
Examples found in repository?
26fn main() -> Result<(), Box<dyn Error>> {
27 pel::init();
28 // Dynamics models require planetary constants and ephemerides to be defined.
29 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
30 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
31
32 // Download the regularly update of the James Webb Space Telescope reconstucted (or definitive) ephemeris.
33 // Refer to https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/aareadme.txt for details.
34 let mut latest_jwst_ephem = MetaFile {
35 uri: "https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/jwst_rec.bsp".to_string(),
36 crc32: None,
37 };
38 latest_jwst_ephem.process(true)?;
39
40 // Load this ephem in the general Almanac we're using for this analysis.
41 let almanac = Arc::new(
42 MetaAlmanac::latest()
43 .map_err(Box::new)?
44 .load_from_metafile(latest_jwst_ephem, true)?,
45 );
46
47 // By loading this ephemeris file in the ANISE GUI or ANISE CLI, we can find the NAIF ID of the JWST
48 // in the BSP. We need this ID in order to query the ephemeris.
49 const JWST_NAIF_ID: i32 = -170;
50 // Let's build a frame in the J2000 orientation centered on the JWST.
51 const JWST_J2000: Frame = Frame::from_ephem_j2000(JWST_NAIF_ID);
52
53 // Since the ephemeris file is updated regularly, we'll just grab the latest state in the ephem.
54 let (earliest_epoch, latest_epoch) = almanac.spk_domain(JWST_NAIF_ID)?;
55 println!("JWST defined from {earliest_epoch} to {latest_epoch}");
56 // Fetch the state, printing it in the Earth J2000 frame.
57 let jwst_orbit = almanac.transform(JWST_J2000, EARTH_J2000, latest_epoch, None)?;
58 println!("{jwst_orbit:x}");
59
60 // Build the spacecraft
61 // SRP area assumed to be the full sunshield and mass if 6200.0 kg, c.f. https://webb.nasa.gov/content/about/faqs/facts.html
62 // SRP Coefficient of reflectivity assumed to be that of Kapton, i.e. 2 - 0.44 = 1.56, table 1 from https://amostech.com/TechnicalPapers/2018/Poster/Bengtson.pdf
63 let jwst = Spacecraft::builder()
64 .orbit(jwst_orbit)
65 .srp(SRPData {
66 area_m2: 21.197 * 14.162,
67 coeff_reflectivity: 1.56,
68 })
69 .mass(Mass::from_dry_mass(6200.0))
70 .build();
71
72 // Build up the spacecraft uncertainty builder.
73 // We can use the spacecraft uncertainty structure to build this up.
74 // We start by specifying the nominal state (as defined above), then the uncertainty in position and velocity
75 // in the RIC frame. We could also specify the Cr, Cd, and mass uncertainties, but these aren't accounted for until
76 // Nyx can also estimate the deviation of the spacecraft parameters.
77 let jwst_uncertainty = SpacecraftUncertainty::builder()
78 .nominal(jwst)
79 .frame(LocalFrame::RIC)
80 .x_km(0.5)
81 .y_km(0.3)
82 .z_km(1.5)
83 .vx_km_s(1e-4)
84 .vy_km_s(0.6e-3)
85 .vz_km_s(3e-3)
86 .build();
87
88 println!("{jwst_uncertainty}");
89
90 // Build the Kalman filter estimate.
91 // Note that we could have used the KfEstimate structure directly (as seen throughout the OD integration tests)
92 // but this approach requires quite a bit more boilerplate code.
93 let jwst_estimate = jwst_uncertainty.to_estimate()?;
94
95 // Set up the spacecraft dynamics.
96 // We'll use the point masses of the Earth, Sun, Jupiter (barycenter, because it's in the DE440), and the Moon.
97 // We'll also enable solar radiation pressure since the James Webb has a huge and highly reflective sun shield.
98
99 let orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN, JUPITER_BARYCENTER]);
100 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
101
102 // Finalize setting up the dynamics.
103 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
104
105 // Build the propagator set up to use for the whole analysis.
106 let setup = Propagator::default(dynamics);
107
108 // All of the analysis will use this duration.
109 let prediction_duration = 6.5 * Unit::Day;
110
111 // === Covariance mapping ===
112 // For the covariance mapping / prediction, we'll use the common orbit determination approach.
113 // This is done by setting up a spacecraft Kalman filter OD process, and predicting for the analysis duration.
114
115 // Build the propagation instance for the OD process.
116 let odp = SpacecraftKalmanOD::new(
117 setup.clone(),
118 KalmanVariant::DeviationTracking,
119 None,
120 BTreeMap::new(),
121 almanac.clone(),
122 );
123
124 // The prediction step is 1 minute by default, configured in the OD process, i.e. how often we want to know the covariance.
125 assert_eq!(odp.max_step, 1_i64.minutes());
126 // Finally, predict, and export the trajectory with covariance to a parquet file.
127 let od_sol = odp.predict_for(jwst_estimate, prediction_duration)?;
128 od_sol.to_parquet("./02_jwst_covar_map.parquet", ExportCfg::default())?;
129
130 // === Monte Carlo framework ===
131 // Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
132
133 let my_mc = MonteCarlo::new(
134 jwst, // Nominal state
135 jwst_estimate.to_random_variable()?,
136 "02_jwst".to_string(), // Scenario name
137 None, // No specific seed specified, so one will be drawn from the computer's entropy.
138 );
139
140 let num_runs = 5_000;
141 let rslts = my_mc.run_until_epoch(
142 setup,
143 almanac.clone(),
144 jwst.epoch() + prediction_duration,
145 num_runs,
146 );
147
148 assert_eq!(rslts.runs.len(), num_runs);
149 // Finally, export these results, computing the eclipse percentage for all of these results.
150
151 rslts.to_parquet("02_jwst_monte_carlo.parquet", ExportCfg::default())?;
152
153 Ok(())
154}pub fn transform_to(
&self,
state: CartesianState,
observer_frame: Frame,
ab_corr: Option<Aberration>,
) -> Result<CartesianState, AlmanacError>
pub fn transform_to( &self, state: CartesianState, observer_frame: Frame, ab_corr: Option<Aberration>, ) -> Result<CartesianState, AlmanacError>
Returns the provided state as seen from the observer frame, given the aberration.
Examples found in repository?
34fn main() -> Result<(), Box<dyn Error>> {
35 pel::init();
36
37 // ====================== //
38 // === ALMANAC SET UP === //
39 // ====================== //
40
41 let manifest_dir =
42 PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap_or(".".to_string()));
43
44 let out = manifest_dir.join("data/04_output/");
45
46 let almanac = Arc::new(
47 Almanac::new(
48 &manifest_dir
49 .join("data/01_planetary/pck08.pca")
50 .to_string_lossy(),
51 )
52 .unwrap()
53 .load(
54 &manifest_dir
55 .join("data/01_planetary/de440s.bsp")
56 .to_string_lossy(),
57 )
58 .unwrap(),
59 );
60
61 let eme2k = almanac.frame_info(EARTH_J2000).unwrap();
62 let moon_iau = almanac.frame_info(IAU_MOON_FRAME).unwrap();
63
64 let epoch = Epoch::from_gregorian_tai(2021, 5, 29, 19, 51, 16, 852_000);
65 let nrho = Orbit::cartesian(
66 166_473.631_302_239_7,
67 -274_715.487_253_382_7,
68 -211_233.210_176_686_7,
69 0.933_451_604_520_018_4,
70 0.436_775_046_841_900_9,
71 -0.082_211_021_250_348_95,
72 epoch,
73 eme2k,
74 );
75
76 let tx_nrho_sc = Spacecraft::from(nrho);
77
78 let state_luna = almanac.transform_to(nrho, MOON_J2000, None).unwrap();
79 println!("Start state (dynamics: Earth, Moon, Sun gravity):\n{state_luna}");
80
81 let bodies = vec![EARTH, SUN];
82 let dynamics = SpacecraftDynamics::new(OrbitalDynamics::point_masses(bodies));
83
84 let setup = Propagator::rk89(
85 dynamics,
86 IntegratorOptions::builder().max_step(0.5.minutes()).build(),
87 );
88
89 /* == Propagate the NRHO vehicle == */
90 let prop_time = 1.1 * state_luna.period().unwrap();
91
92 let (nrho_final, mut tx_traj) = setup
93 .with(tx_nrho_sc, almanac.clone())
94 .for_duration_with_traj(prop_time)
95 .unwrap();
96
97 tx_traj.name = Some("NRHO Tx SC".to_string());
98
99 println!("{tx_traj}");
100
101 /* == Propagate an LLO vehicle == */
102 let llo_orbit =
103 Orbit::try_keplerian_altitude(110.0, 1e-4, 90.0, 0.0, 0.0, 0.0, epoch, moon_iau).unwrap();
104
105 let llo_sc = Spacecraft::builder().orbit(llo_orbit).build();
106
107 let (_, llo_traj) = setup
108 .with(llo_sc, almanac.clone())
109 .until_epoch_with_traj(nrho_final.epoch())
110 .unwrap();
111
112 // Export the subset of the first two hours.
113 llo_traj
114 .clone()
115 .filter_by_offset(..2.hours())
116 .to_parquet_simple(out.join("05_caps_llo_truth.pq"))?;
117
118 /* == Setup the interlink == */
119
120 let mut measurement_types = IndexSet::new();
121 measurement_types.insert(MeasurementType::Range);
122 measurement_types.insert(MeasurementType::Doppler);
123
124 let mut stochastics = IndexMap::new();
125
126 let sa45_csac_allan_dev = 1e-11;
127
128 stochastics.insert(
129 MeasurementType::Range,
130 StochasticNoise::from_hardware_range_km(
131 sa45_csac_allan_dev,
132 10.0.seconds(),
133 link_specific::ChipRate::StandardT4B,
134 link_specific::SN0::Average,
135 ),
136 );
137
138 stochastics.insert(
139 MeasurementType::Doppler,
140 StochasticNoise::from_hardware_doppler_km_s(
141 sa45_csac_allan_dev,
142 10.0.seconds(),
143 link_specific::CarrierFreq::SBand,
144 link_specific::CN0::Average,
145 ),
146 );
147
148 let interlink = InterlinkTxSpacecraft {
149 traj: tx_traj,
150 measurement_types,
151 integration_time: None,
152 timestamp_noise_s: None,
153 ab_corr: Aberration::LT,
154 stochastic_noises: Some(stochastics),
155 };
156
157 // Devices are the transmitter, which is our NRHO vehicle.
158 let mut devices = BTreeMap::new();
159 devices.insert("NRHO Tx SC".to_string(), interlink);
160
161 let mut configs = BTreeMap::new();
162 configs.insert(
163 "NRHO Tx SC".to_string(),
164 TrkConfig::builder()
165 .strands(vec![Strand {
166 start: epoch,
167 end: nrho_final.epoch(),
168 }])
169 .build(),
170 );
171
172 let mut trk_sim =
173 TrackingArcSim::with_seed(devices.clone(), llo_traj.clone(), configs, 0).unwrap();
174 println!("{trk_sim}");
175
176 let trk_data = trk_sim.generate_measurements(almanac.clone()).unwrap();
177 println!("{trk_data}");
178
179 trk_data
180 .to_parquet_simple(out.clone().join("nrho_interlink_msr.pq"))
181 .unwrap();
182
183 // Run a truth OD where we estimate the LLO position
184 let llo_uncertainty = SpacecraftUncertainty::builder()
185 .nominal(llo_sc)
186 .x_km(1.0)
187 .y_km(1.0)
188 .z_km(1.0)
189 .vx_km_s(1e-3)
190 .vy_km_s(1e-3)
191 .vz_km_s(1e-3)
192 .build();
193
194 let mut proc_devices = devices.clone();
195
196 // Define the initial estimate, randomized, seed for reproducibility
197 let mut initial_estimate = llo_uncertainty.to_estimate_randomized(Some(0)).unwrap();
198 // Inflate the covariance -- https://github.com/nyx-space/nyx/issues/339
199 initial_estimate.covar *= 2.5;
200
201 // Increase the noise in the devices to accept more measurements.
202
203 for link in proc_devices.values_mut() {
204 for noise in &mut link.stochastic_noises.as_mut().unwrap().values_mut() {
205 *noise.white_noise.as_mut().unwrap() *= 3.0;
206 }
207 }
208
209 let init_err = initial_estimate
210 .orbital_state()
211 .ric_difference(&llo_orbit)
212 .unwrap();
213
214 println!("initial estimate:\n{initial_estimate}");
215 println!("RIC errors = {init_err}",);
216
217 let odp = InterlinkKalmanOD::new(
218 setup.clone(),
219 KalmanVariant::ReferenceUpdate,
220 Some(ResidRejectCrit::default()),
221 proc_devices,
222 almanac.clone(),
223 );
224
225 // Shrink the data to process.
226 let arc = trk_data.filter_by_offset(..2.hours());
227
228 let od_sol = odp.process_arc(initial_estimate, &arc).unwrap();
229
230 println!("{od_sol}");
231
232 od_sol
233 .to_parquet(
234 out.join("05_caps_interlink_od_sol.pq"),
235 ExportCfg::default(),
236 )
237 .unwrap();
238
239 let od_traj = od_sol.to_traj().unwrap();
240
241 od_traj
242 .ric_diff_to_parquet(
243 &llo_traj,
244 out.join("05_caps_interlink_llo_est_error.pq"),
245 ExportCfg::default(),
246 )
247 .unwrap();
248
249 let final_est = od_sol.estimates.last().unwrap();
250 assert!(final_est.within_3sigma(), "should be within 3 sigma");
251
252 println!("ESTIMATE\n{final_est:x}\n");
253 let truth = llo_traj.at(final_est.epoch()).unwrap();
254 println!("TRUTH\n{truth:x}");
255
256 let final_err = truth
257 .orbit
258 .ric_difference(&final_est.orbital_state())
259 .unwrap();
260 println!("ERROR {final_err}");
261
262 // Build the residuals versus reference plot.
263 let rvr_sol = odp
264 .process_arc(initial_estimate, &arc.resid_vs_ref_check())
265 .unwrap();
266
267 rvr_sol
268 .to_parquet(
269 out.join("05_caps_interlink_resid_v_ref.pq"),
270 ExportCfg::default(),
271 )
272 .unwrap();
273
274 let final_rvr = rvr_sol.estimates.last().unwrap();
275
276 println!("RMAG error {:.3} m", final_err.rmag_km() * 1e3);
277 println!(
278 "Pure prop error {:.3} m",
279 final_rvr
280 .orbital_state()
281 .ric_difference(&final_est.orbital_state())
282 .unwrap()
283 .rmag_km()
284 * 1e3
285 );
286
287 Ok(())
288}More examples
26fn main() -> Result<(), Box<dyn Error>> {
27 pel::init();
28 // Dynamics models require planetary constants and ephemerides to be defined.
29 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
30 // This will automatically download the DE440s planetary ephemeris,
31 // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
32 // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
33 // planetary constants kernels.
34 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
35 // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
36 // references to many functions.
37 let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
38 // Define the orbit epoch
39 let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
40
41 // Define the orbit.
42 // First we need to fetch the Earth J2000 from information from the Almanac.
43 // This allows the frame to include the gravitational parameters and the shape of the Earth,
44 // defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
45 // by loading a different set of planetary constants.
46 let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
47
48 // Placing this GEO bird just above Colorado.
49 // In theory, the eccentricity is zero, but in practice, it's about 1e-5 to 1e-6 at best.
50 let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
51 // Print in in Keplerian form.
52 println!("{orbit:x}");
53
54 let state_bf = almanac.transform_to(orbit, IAU_EARTH_FRAME, None)?;
55 let (orig_lat_deg, orig_long_deg, orig_alt_km) = state_bf.latlongalt()?;
56
57 // Nyx is used for high fidelity propagation, not Keplerian propagation as above.
58 // Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
59 // models such as solar radiation pressure.
60
61 // Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
62 let sc = Spacecraft::builder()
63 .orbit(orbit)
64 .mass(Mass::from_dry_mass(9.60))
65 .srp(SRPData {
66 area_m2: 10e-4,
67 coeff_reflectivity: 1.1,
68 })
69 .build();
70 println!("{sc:x}");
71
72 // Set up the spacecraft dynamics.
73
74 // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
75 // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
76 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
77
78 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
79 // We're using the JGM3 model here, which is the default in GMAT.
80 let mut jgm3_meta = MetaFile {
81 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
82 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
83 };
84 // And let's download it if we don't have it yet.
85 jgm3_meta.process(true)?;
86
87 // Build the spherical harmonics.
88 // The harmonics must be computed in the body fixed frame.
89 // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
90 let harmonics_21x21 = Harmonics::from_stor(
91 almanac.frame_info(IAU_EARTH_FRAME)?,
92 HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
93 );
94
95 // Include the spherical harmonics into the orbital dynamics.
96 orbital_dyn.accel_models.push(harmonics_21x21);
97
98 // We define the solar radiation pressure, using the default solar flux and accounting only
99 // for the eclipsing caused by the Earth and Moon.
100 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
101
102 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
103 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
104 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
105
106 println!("{dynamics}");
107
108 // Finally, let's propagate this orbit to the same epoch as above.
109 // The first returned value is the spacecraft state at the final epoch.
110 // The second value is the full trajectory where the step size is variable step used by the propagator.
111 let (future_sc, trajectory) = Propagator::default(dynamics)
112 .with(sc, almanac.clone())
113 .until_epoch_with_traj(epoch + Unit::Century * 0.03)?;
114
115 println!("=== High fidelity propagation ===");
116 println!(
117 "SMA changed by {:.3} km",
118 orbit.sma_km()? - future_sc.orbit.sma_km()?
119 );
120 println!(
121 "ECC changed by {:.6}",
122 orbit.ecc()? - future_sc.orbit.ecc()?
123 );
124 println!(
125 "INC changed by {:.3e} deg",
126 orbit.inc_deg()? - future_sc.orbit.inc_deg()?
127 );
128 println!(
129 "RAAN changed by {:.3} deg",
130 orbit.raan_deg()? - future_sc.orbit.raan_deg()?
131 );
132 println!(
133 "AOP changed by {:.3} deg",
134 orbit.aop_deg()? - future_sc.orbit.aop_deg()?
135 );
136 println!(
137 "TA changed by {:.3} deg",
138 orbit.ta_deg()? - future_sc.orbit.ta_deg()?
139 );
140
141 // We also have access to the full trajectory throughout the propagation.
142 println!("{trajectory}");
143
144 println!("Spacecraft params after 3 years without active control:\n{future_sc:x}");
145
146 // With the trajectory, let's build a few data products.
147
148 // 1. Export the trajectory as a parquet file, which includes the Keplerian orbital elements.
149
150 let analysis_step = Unit::Minute * 5;
151
152 trajectory.to_parquet(
153 "./03_geo_hf_prop.parquet",
154 ExportCfg::builder().step(analysis_step).build(),
155 )?;
156
157 // 2. Compute the latitude, longitude, and altitude throughout the trajectory by rotating the spacecraft position into the Earth body fixed frame.
158
159 // We iterate over the trajectory, grabbing a state every two minutes.
160 let mut offset_s = vec![];
161 let mut epoch_str = vec![];
162 let mut longitude_deg = vec![];
163 let mut latitude_deg = vec![];
164 let mut altitude_km = vec![];
165
166 for state in trajectory.every(analysis_step) {
167 // Convert the GEO bird state into the body fixed frame, and keep track of its latitude, longitude, and altitude.
168 // These define the GEO stationkeeping box.
169
170 let this_epoch = state.epoch();
171
172 offset_s.push((this_epoch - orbit.epoch).to_seconds());
173 epoch_str.push(this_epoch.to_isoformat());
174
175 let state_bf = almanac.transform_to(state.orbit, IAU_EARTH_FRAME, None)?;
176 let (lat_deg, long_deg, alt_km) = state_bf.latlongalt()?;
177 longitude_deg.push(long_deg);
178 latitude_deg.push(lat_deg);
179 altitude_km.push(alt_km);
180 }
181
182 println!(
183 "Longitude changed by {:.3} deg -- Box is 0.1 deg E-W",
184 orig_long_deg - longitude_deg.last().unwrap()
185 );
186
187 println!(
188 "Latitude changed by {:.3} deg -- Box is 0.05 deg N-S",
189 orig_lat_deg - latitude_deg.last().unwrap()
190 );
191
192 println!(
193 "Altitude changed by {:.3} km -- Box is 30 km",
194 orig_alt_km - altitude_km.last().unwrap()
195 );
196
197 // Build the station keeping data frame.
198 let mut sk_df = df!(
199 "Offset (s)" => offset_s.clone(),
200 "Epoch (UTC)" => epoch_str.clone(),
201 "Longitude E-W (deg)" => longitude_deg,
202 "Latitude N-S (deg)" => latitude_deg,
203 "Altitude (km)" => altitude_km,
204
205 )?;
206
207 // Create a file to write the Parquet to
208 let file = File::create("./03_geo_lla.parquet").expect("Could not create file");
209
210 // Create a ParquetWriter and write the DataFrame to the file
211 ParquetWriter::new(file).finish(&mut sk_df)?;
212
213 Ok(())
214}pub fn state_of(
&self,
object: i32,
observer: Frame,
epoch: Epoch,
ab_corr: Option<Aberration>,
) -> Result<CartesianState, AlmanacError>
pub fn state_of( &self, object: i32, observer: Frame, epoch: Epoch, ab_corr: Option<Aberration>, ) -> Result<CartesianState, AlmanacError>
Returns the Cartesian state of the object as seen from the provided observer frame (essentially spkezr).
§Note
The units will be those of the underlying ephemeris data (typically km and km/s)
pub fn spk_ezr(
&self,
target: i32,
epoch: Epoch,
frame: i32,
observer: i32,
ab_corr: Option<Aberration>,
) -> Result<CartesianState, AlmanacError>
pub fn spk_ezr( &self, target: i32, epoch: Epoch, frame: i32, observer: i32, ab_corr: Option<Aberration>, ) -> Result<CartesianState, AlmanacError>
Alias fo SPICE’s spkezr where the inputs must be the NAIF IDs of the objects and frames with the caveat that the aberration is moved to the last positional argument.
pub fn transform_state_to(
&self,
position: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>,
velocity: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
ab_corr: Option<Aberration>,
distance_unit: LengthUnit,
time_unit: Unit,
) -> Result<CartesianState, AlmanacError>
pub fn transform_state_to( &self, position: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, velocity: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, from_frame: Frame, to_frame: Frame, epoch: Epoch, ab_corr: Option<Aberration>, distance_unit: LengthUnit, time_unit: Unit, ) -> Result<CartesianState, AlmanacError>
Translates a state with its origin (to_frame) and given its units (distance_unit, time_unit), returns that state with respect to the requested frame
WARNING: This function only performs the translation and no rotation whatsoever. Use the transform_state_to function instead to include rotations.
pub fn unit_vector(
&self,
target_frame: Frame,
observer_frame: Frame,
epoch: Epoch,
ab_corr: Option<Aberration>,
) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, AlmanacError>
pub fn unit_vector( &self, target_frame: Frame, observer_frame: Frame, epoch: Epoch, ab_corr: Option<Aberration>, ) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, AlmanacError>
pub fn sun_unit_vector(
&self,
epoch: Epoch,
observer_frame: Frame,
ab_corr: Option<Aberration>,
) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, AlmanacError>
pub fn sun_unit_vector( &self, epoch: Epoch, observer_frame: Frame, ab_corr: Option<Aberration>, ) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, AlmanacError>
pub fn earth_sun_unit_vector(
&self,
epoch: Epoch,
ab_corr: Option<Aberration>,
) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, AlmanacError>
pub fn earth_sun_unit_vector( &self, epoch: Epoch, ab_corr: Option<Aberration>, ) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, AlmanacError>
Returns the unitary 3D vector between Earth and Sun at desired Epoch.
§impl Almanac
impl Almanac
pub fn load_from_metafile(
self,
metafile: MetaFile,
autodelete: bool,
) -> Result<Almanac, AlmanacError>
pub fn load_from_metafile( self, metafile: MetaFile, autodelete: bool, ) -> Result<Almanac, AlmanacError>
Load from the provided MetaFile, downloading it if necessary. Set autodelete to true to automatically delete lock files. Lock files are important in multi-threaded loads.
Examples found in repository?
26fn main() -> Result<(), Box<dyn Error>> {
27 pel::init();
28 // Dynamics models require planetary constants and ephemerides to be defined.
29 // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
30 // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
31
32 // Download the regularly update of the James Webb Space Telescope reconstucted (or definitive) ephemeris.
33 // Refer to https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/aareadme.txt for details.
34 let mut latest_jwst_ephem = MetaFile {
35 uri: "https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/jwst_rec.bsp".to_string(),
36 crc32: None,
37 };
38 latest_jwst_ephem.process(true)?;
39
40 // Load this ephem in the general Almanac we're using for this analysis.
41 let almanac = Arc::new(
42 MetaAlmanac::latest()
43 .map_err(Box::new)?
44 .load_from_metafile(latest_jwst_ephem, true)?,
45 );
46
47 // By loading this ephemeris file in the ANISE GUI or ANISE CLI, we can find the NAIF ID of the JWST
48 // in the BSP. We need this ID in order to query the ephemeris.
49 const JWST_NAIF_ID: i32 = -170;
50 // Let's build a frame in the J2000 orientation centered on the JWST.
51 const JWST_J2000: Frame = Frame::from_ephem_j2000(JWST_NAIF_ID);
52
53 // Since the ephemeris file is updated regularly, we'll just grab the latest state in the ephem.
54 let (earliest_epoch, latest_epoch) = almanac.spk_domain(JWST_NAIF_ID)?;
55 println!("JWST defined from {earliest_epoch} to {latest_epoch}");
56 // Fetch the state, printing it in the Earth J2000 frame.
57 let jwst_orbit = almanac.transform(JWST_J2000, EARTH_J2000, latest_epoch, None)?;
58 println!("{jwst_orbit:x}");
59
60 // Build the spacecraft
61 // SRP area assumed to be the full sunshield and mass if 6200.0 kg, c.f. https://webb.nasa.gov/content/about/faqs/facts.html
62 // SRP Coefficient of reflectivity assumed to be that of Kapton, i.e. 2 - 0.44 = 1.56, table 1 from https://amostech.com/TechnicalPapers/2018/Poster/Bengtson.pdf
63 let jwst = Spacecraft::builder()
64 .orbit(jwst_orbit)
65 .srp(SRPData {
66 area_m2: 21.197 * 14.162,
67 coeff_reflectivity: 1.56,
68 })
69 .mass(Mass::from_dry_mass(6200.0))
70 .build();
71
72 // Build up the spacecraft uncertainty builder.
73 // We can use the spacecraft uncertainty structure to build this up.
74 // We start by specifying the nominal state (as defined above), then the uncertainty in position and velocity
75 // in the RIC frame. We could also specify the Cr, Cd, and mass uncertainties, but these aren't accounted for until
76 // Nyx can also estimate the deviation of the spacecraft parameters.
77 let jwst_uncertainty = SpacecraftUncertainty::builder()
78 .nominal(jwst)
79 .frame(LocalFrame::RIC)
80 .x_km(0.5)
81 .y_km(0.3)
82 .z_km(1.5)
83 .vx_km_s(1e-4)
84 .vy_km_s(0.6e-3)
85 .vz_km_s(3e-3)
86 .build();
87
88 println!("{jwst_uncertainty}");
89
90 // Build the Kalman filter estimate.
91 // Note that we could have used the KfEstimate structure directly (as seen throughout the OD integration tests)
92 // but this approach requires quite a bit more boilerplate code.
93 let jwst_estimate = jwst_uncertainty.to_estimate()?;
94
95 // Set up the spacecraft dynamics.
96 // We'll use the point masses of the Earth, Sun, Jupiter (barycenter, because it's in the DE440), and the Moon.
97 // We'll also enable solar radiation pressure since the James Webb has a huge and highly reflective sun shield.
98
99 let orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN, JUPITER_BARYCENTER]);
100 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
101
102 // Finalize setting up the dynamics.
103 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
104
105 // Build the propagator set up to use for the whole analysis.
106 let setup = Propagator::default(dynamics);
107
108 // All of the analysis will use this duration.
109 let prediction_duration = 6.5 * Unit::Day;
110
111 // === Covariance mapping ===
112 // For the covariance mapping / prediction, we'll use the common orbit determination approach.
113 // This is done by setting up a spacecraft Kalman filter OD process, and predicting for the analysis duration.
114
115 // Build the propagation instance for the OD process.
116 let odp = SpacecraftKalmanOD::new(
117 setup.clone(),
118 KalmanVariant::DeviationTracking,
119 None,
120 BTreeMap::new(),
121 almanac.clone(),
122 );
123
124 // The prediction step is 1 minute by default, configured in the OD process, i.e. how often we want to know the covariance.
125 assert_eq!(odp.max_step, 1_i64.minutes());
126 // Finally, predict, and export the trajectory with covariance to a parquet file.
127 let od_sol = odp.predict_for(jwst_estimate, prediction_duration)?;
128 od_sol.to_parquet("./02_jwst_covar_map.parquet", ExportCfg::default())?;
129
130 // === Monte Carlo framework ===
131 // Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
132
133 let my_mc = MonteCarlo::new(
134 jwst, // Nominal state
135 jwst_estimate.to_random_variable()?,
136 "02_jwst".to_string(), // Scenario name
137 None, // No specific seed specified, so one will be drawn from the computer's entropy.
138 );
139
140 let num_runs = 5_000;
141 let rslts = my_mc.run_until_epoch(
142 setup,
143 almanac.clone(),
144 jwst.epoch() + prediction_duration,
145 num_runs,
146 );
147
148 assert_eq!(rslts.runs.len(), num_runs);
149 // Finally, export these results, computing the eclipse percentage for all of these results.
150
151 rslts.to_parquet("02_jwst_monte_carlo.parquet", ExportCfg::default())?;
152
153 Ok(())
154}pub fn to_metaalmanac(&self) -> MetaAlmanac
pub fn to_metaalmanac(&self) -> MetaAlmanac
Saves the current configuration to a MetaAlmanac for future reloading from the local file system.
WARNING: If data was loaded from its raw bytes, or if a custom alias was used, then the MetaFile produced will not be usable. The alias used for each data type is expected to be a path. Further, all paths are ASSUMED to be loaded from the same directory. The Almanac does not resolve directories for you.
§impl Almanac
impl Almanac
pub fn new(path: &str) -> Result<Almanac, AlmanacError>
pub fn new(path: &str) -> Result<Almanac, AlmanacError>
Initializes a new Almanac from the provided file path, guessing at the file type
Examples found in repository?
34fn main() -> Result<(), Box<dyn Error>> {
35 pel::init();
36
37 // ====================== //
38 // === ALMANAC SET UP === //
39 // ====================== //
40
41 let manifest_dir =
42 PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap_or(".".to_string()));
43
44 let out = manifest_dir.join("data/04_output/");
45
46 let almanac = Arc::new(
47 Almanac::new(
48 &manifest_dir
49 .join("data/01_planetary/pck08.pca")
50 .to_string_lossy(),
51 )
52 .unwrap()
53 .load(
54 &manifest_dir
55 .join("data/01_planetary/de440s.bsp")
56 .to_string_lossy(),
57 )
58 .unwrap(),
59 );
60
61 let eme2k = almanac.frame_info(EARTH_J2000).unwrap();
62 let moon_iau = almanac.frame_info(IAU_MOON_FRAME).unwrap();
63
64 let epoch = Epoch::from_gregorian_tai(2021, 5, 29, 19, 51, 16, 852_000);
65 let nrho = Orbit::cartesian(
66 166_473.631_302_239_7,
67 -274_715.487_253_382_7,
68 -211_233.210_176_686_7,
69 0.933_451_604_520_018_4,
70 0.436_775_046_841_900_9,
71 -0.082_211_021_250_348_95,
72 epoch,
73 eme2k,
74 );
75
76 let tx_nrho_sc = Spacecraft::from(nrho);
77
78 let state_luna = almanac.transform_to(nrho, MOON_J2000, None).unwrap();
79 println!("Start state (dynamics: Earth, Moon, Sun gravity):\n{state_luna}");
80
81 let bodies = vec![EARTH, SUN];
82 let dynamics = SpacecraftDynamics::new(OrbitalDynamics::point_masses(bodies));
83
84 let setup = Propagator::rk89(
85 dynamics,
86 IntegratorOptions::builder().max_step(0.5.minutes()).build(),
87 );
88
89 /* == Propagate the NRHO vehicle == */
90 let prop_time = 1.1 * state_luna.period().unwrap();
91
92 let (nrho_final, mut tx_traj) = setup
93 .with(tx_nrho_sc, almanac.clone())
94 .for_duration_with_traj(prop_time)
95 .unwrap();
96
97 tx_traj.name = Some("NRHO Tx SC".to_string());
98
99 println!("{tx_traj}");
100
101 /* == Propagate an LLO vehicle == */
102 let llo_orbit =
103 Orbit::try_keplerian_altitude(110.0, 1e-4, 90.0, 0.0, 0.0, 0.0, epoch, moon_iau).unwrap();
104
105 let llo_sc = Spacecraft::builder().orbit(llo_orbit).build();
106
107 let (_, llo_traj) = setup
108 .with(llo_sc, almanac.clone())
109 .until_epoch_with_traj(nrho_final.epoch())
110 .unwrap();
111
112 // Export the subset of the first two hours.
113 llo_traj
114 .clone()
115 .filter_by_offset(..2.hours())
116 .to_parquet_simple(out.join("05_caps_llo_truth.pq"))?;
117
118 /* == Setup the interlink == */
119
120 let mut measurement_types = IndexSet::new();
121 measurement_types.insert(MeasurementType::Range);
122 measurement_types.insert(MeasurementType::Doppler);
123
124 let mut stochastics = IndexMap::new();
125
126 let sa45_csac_allan_dev = 1e-11;
127
128 stochastics.insert(
129 MeasurementType::Range,
130 StochasticNoise::from_hardware_range_km(
131 sa45_csac_allan_dev,
132 10.0.seconds(),
133 link_specific::ChipRate::StandardT4B,
134 link_specific::SN0::Average,
135 ),
136 );
137
138 stochastics.insert(
139 MeasurementType::Doppler,
140 StochasticNoise::from_hardware_doppler_km_s(
141 sa45_csac_allan_dev,
142 10.0.seconds(),
143 link_specific::CarrierFreq::SBand,
144 link_specific::CN0::Average,
145 ),
146 );
147
148 let interlink = InterlinkTxSpacecraft {
149 traj: tx_traj,
150 measurement_types,
151 integration_time: None,
152 timestamp_noise_s: None,
153 ab_corr: Aberration::LT,
154 stochastic_noises: Some(stochastics),
155 };
156
157 // Devices are the transmitter, which is our NRHO vehicle.
158 let mut devices = BTreeMap::new();
159 devices.insert("NRHO Tx SC".to_string(), interlink);
160
161 let mut configs = BTreeMap::new();
162 configs.insert(
163 "NRHO Tx SC".to_string(),
164 TrkConfig::builder()
165 .strands(vec![Strand {
166 start: epoch,
167 end: nrho_final.epoch(),
168 }])
169 .build(),
170 );
171
172 let mut trk_sim =
173 TrackingArcSim::with_seed(devices.clone(), llo_traj.clone(), configs, 0).unwrap();
174 println!("{trk_sim}");
175
176 let trk_data = trk_sim.generate_measurements(almanac.clone()).unwrap();
177 println!("{trk_data}");
178
179 trk_data
180 .to_parquet_simple(out.clone().join("nrho_interlink_msr.pq"))
181 .unwrap();
182
183 // Run a truth OD where we estimate the LLO position
184 let llo_uncertainty = SpacecraftUncertainty::builder()
185 .nominal(llo_sc)
186 .x_km(1.0)
187 .y_km(1.0)
188 .z_km(1.0)
189 .vx_km_s(1e-3)
190 .vy_km_s(1e-3)
191 .vz_km_s(1e-3)
192 .build();
193
194 let mut proc_devices = devices.clone();
195
196 // Define the initial estimate, randomized, seed for reproducibility
197 let mut initial_estimate = llo_uncertainty.to_estimate_randomized(Some(0)).unwrap();
198 // Inflate the covariance -- https://github.com/nyx-space/nyx/issues/339
199 initial_estimate.covar *= 2.5;
200
201 // Increase the noise in the devices to accept more measurements.
202
203 for link in proc_devices.values_mut() {
204 for noise in &mut link.stochastic_noises.as_mut().unwrap().values_mut() {
205 *noise.white_noise.as_mut().unwrap() *= 3.0;
206 }
207 }
208
209 let init_err = initial_estimate
210 .orbital_state()
211 .ric_difference(&llo_orbit)
212 .unwrap();
213
214 println!("initial estimate:\n{initial_estimate}");
215 println!("RIC errors = {init_err}",);
216
217 let odp = InterlinkKalmanOD::new(
218 setup.clone(),
219 KalmanVariant::ReferenceUpdate,
220 Some(ResidRejectCrit::default()),
221 proc_devices,
222 almanac.clone(),
223 );
224
225 // Shrink the data to process.
226 let arc = trk_data.filter_by_offset(..2.hours());
227
228 let od_sol = odp.process_arc(initial_estimate, &arc).unwrap();
229
230 println!("{od_sol}");
231
232 od_sol
233 .to_parquet(
234 out.join("05_caps_interlink_od_sol.pq"),
235 ExportCfg::default(),
236 )
237 .unwrap();
238
239 let od_traj = od_sol.to_traj().unwrap();
240
241 od_traj
242 .ric_diff_to_parquet(
243 &llo_traj,
244 out.join("05_caps_interlink_llo_est_error.pq"),
245 ExportCfg::default(),
246 )
247 .unwrap();
248
249 let final_est = od_sol.estimates.last().unwrap();
250 assert!(final_est.within_3sigma(), "should be within 3 sigma");
251
252 println!("ESTIMATE\n{final_est:x}\n");
253 let truth = llo_traj.at(final_est.epoch()).unwrap();
254 println!("TRUTH\n{truth:x}");
255
256 let final_err = truth
257 .orbit
258 .ric_difference(&final_est.orbital_state())
259 .unwrap();
260 println!("ERROR {final_err}");
261
262 // Build the residuals versus reference plot.
263 let rvr_sol = odp
264 .process_arc(initial_estimate, &arc.resid_vs_ref_check())
265 .unwrap();
266
267 rvr_sol
268 .to_parquet(
269 out.join("05_caps_interlink_resid_v_ref.pq"),
270 ExportCfg::default(),
271 )
272 .unwrap();
273
274 let final_rvr = rvr_sol.estimates.last().unwrap();
275
276 println!("RMAG error {:.3} m", final_err.rmag_km() * 1e3);
277 println!(
278 "Pure prop error {:.3} m",
279 final_rvr
280 .orbital_state()
281 .ric_difference(&final_est.orbital_state())
282 .unwrap()
283 .rmag_km()
284 * 1e3
285 );
286
287 Ok(())
288}pub fn with_spacecraft_data(
self,
spacecraft_data: DataSet<SpacecraftData>,
) -> Almanac
pub fn with_spacecraft_data( self, spacecraft_data: DataSet<SpacecraftData>, ) -> Almanac
Loads the provided spacecraft data.
pub fn with_spacecraft_data_as(
self,
spacecraft_data: DataSet<SpacecraftData>,
alias: Option<String>,
) -> Almanac
pub fn with_spacecraft_data_as( self, spacecraft_data: DataSet<SpacecraftData>, alias: Option<String>, ) -> Almanac
Loads the provided spacecraft data.
pub fn with_euler_parameters(
self,
ep_dataset: DataSet<EulerParameter>,
) -> Almanac
pub fn with_euler_parameters( self, ep_dataset: DataSet<EulerParameter>, ) -> Almanac
Loads the provided Euler parameter data into a clone of this original Almanac.
pub fn with_euler_parameters_as(
self,
ep_dataset: DataSet<EulerParameter>,
alias: Option<String>,
) -> Almanac
pub fn with_euler_parameters_as( self, ep_dataset: DataSet<EulerParameter>, alias: Option<String>, ) -> Almanac
Loads the provided Euler parameter data.
pub fn with_location_data(self, loc_dataset: DataSet<Location>) -> Almanac
pub fn with_location_data(self, loc_dataset: DataSet<Location>) -> Almanac
Loads the provided location data.
pub fn with_location_data_as(
self,
loc_dataset: DataSet<Location>,
alias: Option<String>,
) -> Almanac
pub fn with_location_data_as( self, loc_dataset: DataSet<Location>, alias: Option<String>, ) -> Almanac
Loads the provided location data.
pub fn with_instrument_data(self, dataset: DataSet<Instrument>) -> Almanac
pub fn with_instrument_data(self, dataset: DataSet<Instrument>) -> Almanac
Loads the provided instrument data.
pub fn with_instrument_data_as(
self,
dataset: DataSet<Instrument>,
alias: Option<String>,
) -> Almanac
pub fn with_instrument_data_as( self, dataset: DataSet<Instrument>, alias: Option<String>, ) -> Almanac
Loads the provided instrument data.
pub fn load_from_bytes(self, bytes: BytesMut) -> Result<Almanac, AlmanacError>
pub fn load_from_bytes(self, bytes: BytesMut) -> Result<Almanac, AlmanacError>
Loads the provides bytes as one of the data types supported in ANISE.
pub fn load(self, path: &str) -> Result<Almanac, AlmanacError>
pub fn load(self, path: &str) -> Result<Almanac, AlmanacError>
Generic function that tries to load the provided path guessing to the file type.
Examples found in repository?
34fn main() -> Result<(), Box<dyn Error>> {
35 pel::init();
36
37 // ====================== //
38 // === ALMANAC SET UP === //
39 // ====================== //
40
41 let manifest_dir =
42 PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap_or(".".to_string()));
43
44 let out = manifest_dir.join("data/04_output/");
45
46 let almanac = Arc::new(
47 Almanac::new(
48 &manifest_dir
49 .join("data/01_planetary/pck08.pca")
50 .to_string_lossy(),
51 )
52 .unwrap()
53 .load(
54 &manifest_dir
55 .join("data/01_planetary/de440s.bsp")
56 .to_string_lossy(),
57 )
58 .unwrap(),
59 );
60
61 let eme2k = almanac.frame_info(EARTH_J2000).unwrap();
62 let moon_iau = almanac.frame_info(IAU_MOON_FRAME).unwrap();
63
64 let epoch = Epoch::from_gregorian_tai(2021, 5, 29, 19, 51, 16, 852_000);
65 let nrho = Orbit::cartesian(
66 166_473.631_302_239_7,
67 -274_715.487_253_382_7,
68 -211_233.210_176_686_7,
69 0.933_451_604_520_018_4,
70 0.436_775_046_841_900_9,
71 -0.082_211_021_250_348_95,
72 epoch,
73 eme2k,
74 );
75
76 let tx_nrho_sc = Spacecraft::from(nrho);
77
78 let state_luna = almanac.transform_to(nrho, MOON_J2000, None).unwrap();
79 println!("Start state (dynamics: Earth, Moon, Sun gravity):\n{state_luna}");
80
81 let bodies = vec![EARTH, SUN];
82 let dynamics = SpacecraftDynamics::new(OrbitalDynamics::point_masses(bodies));
83
84 let setup = Propagator::rk89(
85 dynamics,
86 IntegratorOptions::builder().max_step(0.5.minutes()).build(),
87 );
88
89 /* == Propagate the NRHO vehicle == */
90 let prop_time = 1.1 * state_luna.period().unwrap();
91
92 let (nrho_final, mut tx_traj) = setup
93 .with(tx_nrho_sc, almanac.clone())
94 .for_duration_with_traj(prop_time)
95 .unwrap();
96
97 tx_traj.name = Some("NRHO Tx SC".to_string());
98
99 println!("{tx_traj}");
100
101 /* == Propagate an LLO vehicle == */
102 let llo_orbit =
103 Orbit::try_keplerian_altitude(110.0, 1e-4, 90.0, 0.0, 0.0, 0.0, epoch, moon_iau).unwrap();
104
105 let llo_sc = Spacecraft::builder().orbit(llo_orbit).build();
106
107 let (_, llo_traj) = setup
108 .with(llo_sc, almanac.clone())
109 .until_epoch_with_traj(nrho_final.epoch())
110 .unwrap();
111
112 // Export the subset of the first two hours.
113 llo_traj
114 .clone()
115 .filter_by_offset(..2.hours())
116 .to_parquet_simple(out.join("05_caps_llo_truth.pq"))?;
117
118 /* == Setup the interlink == */
119
120 let mut measurement_types = IndexSet::new();
121 measurement_types.insert(MeasurementType::Range);
122 measurement_types.insert(MeasurementType::Doppler);
123
124 let mut stochastics = IndexMap::new();
125
126 let sa45_csac_allan_dev = 1e-11;
127
128 stochastics.insert(
129 MeasurementType::Range,
130 StochasticNoise::from_hardware_range_km(
131 sa45_csac_allan_dev,
132 10.0.seconds(),
133 link_specific::ChipRate::StandardT4B,
134 link_specific::SN0::Average,
135 ),
136 );
137
138 stochastics.insert(
139 MeasurementType::Doppler,
140 StochasticNoise::from_hardware_doppler_km_s(
141 sa45_csac_allan_dev,
142 10.0.seconds(),
143 link_specific::CarrierFreq::SBand,
144 link_specific::CN0::Average,
145 ),
146 );
147
148 let interlink = InterlinkTxSpacecraft {
149 traj: tx_traj,
150 measurement_types,
151 integration_time: None,
152 timestamp_noise_s: None,
153 ab_corr: Aberration::LT,
154 stochastic_noises: Some(stochastics),
155 };
156
157 // Devices are the transmitter, which is our NRHO vehicle.
158 let mut devices = BTreeMap::new();
159 devices.insert("NRHO Tx SC".to_string(), interlink);
160
161 let mut configs = BTreeMap::new();
162 configs.insert(
163 "NRHO Tx SC".to_string(),
164 TrkConfig::builder()
165 .strands(vec![Strand {
166 start: epoch,
167 end: nrho_final.epoch(),
168 }])
169 .build(),
170 );
171
172 let mut trk_sim =
173 TrackingArcSim::with_seed(devices.clone(), llo_traj.clone(), configs, 0).unwrap();
174 println!("{trk_sim}");
175
176 let trk_data = trk_sim.generate_measurements(almanac.clone()).unwrap();
177 println!("{trk_data}");
178
179 trk_data
180 .to_parquet_simple(out.clone().join("nrho_interlink_msr.pq"))
181 .unwrap();
182
183 // Run a truth OD where we estimate the LLO position
184 let llo_uncertainty = SpacecraftUncertainty::builder()
185 .nominal(llo_sc)
186 .x_km(1.0)
187 .y_km(1.0)
188 .z_km(1.0)
189 .vx_km_s(1e-3)
190 .vy_km_s(1e-3)
191 .vz_km_s(1e-3)
192 .build();
193
194 let mut proc_devices = devices.clone();
195
196 // Define the initial estimate, randomized, seed for reproducibility
197 let mut initial_estimate = llo_uncertainty.to_estimate_randomized(Some(0)).unwrap();
198 // Inflate the covariance -- https://github.com/nyx-space/nyx/issues/339
199 initial_estimate.covar *= 2.5;
200
201 // Increase the noise in the devices to accept more measurements.
202
203 for link in proc_devices.values_mut() {
204 for noise in &mut link.stochastic_noises.as_mut().unwrap().values_mut() {
205 *noise.white_noise.as_mut().unwrap() *= 3.0;
206 }
207 }
208
209 let init_err = initial_estimate
210 .orbital_state()
211 .ric_difference(&llo_orbit)
212 .unwrap();
213
214 println!("initial estimate:\n{initial_estimate}");
215 println!("RIC errors = {init_err}",);
216
217 let odp = InterlinkKalmanOD::new(
218 setup.clone(),
219 KalmanVariant::ReferenceUpdate,
220 Some(ResidRejectCrit::default()),
221 proc_devices,
222 almanac.clone(),
223 );
224
225 // Shrink the data to process.
226 let arc = trk_data.filter_by_offset(..2.hours());
227
228 let od_sol = odp.process_arc(initial_estimate, &arc).unwrap();
229
230 println!("{od_sol}");
231
232 od_sol
233 .to_parquet(
234 out.join("05_caps_interlink_od_sol.pq"),
235 ExportCfg::default(),
236 )
237 .unwrap();
238
239 let od_traj = od_sol.to_traj().unwrap();
240
241 od_traj
242 .ric_diff_to_parquet(
243 &llo_traj,
244 out.join("05_caps_interlink_llo_est_error.pq"),
245 ExportCfg::default(),
246 )
247 .unwrap();
248
249 let final_est = od_sol.estimates.last().unwrap();
250 assert!(final_est.within_3sigma(), "should be within 3 sigma");
251
252 println!("ESTIMATE\n{final_est:x}\n");
253 let truth = llo_traj.at(final_est.epoch()).unwrap();
254 println!("TRUTH\n{truth:x}");
255
256 let final_err = truth
257 .orbit
258 .ric_difference(&final_est.orbital_state())
259 .unwrap();
260 println!("ERROR {final_err}");
261
262 // Build the residuals versus reference plot.
263 let rvr_sol = odp
264 .process_arc(initial_estimate, &arc.resid_vs_ref_check())
265 .unwrap();
266
267 rvr_sol
268 .to_parquet(
269 out.join("05_caps_interlink_resid_v_ref.pq"),
270 ExportCfg::default(),
271 )
272 .unwrap();
273
274 let final_rvr = rvr_sol.estimates.last().unwrap();
275
276 println!("RMAG error {:.3} m", final_err.rmag_km() * 1e3);
277 println!(
278 "Pure prop error {:.3} m",
279 final_rvr
280 .orbital_state()
281 .ric_difference(&final_est.orbital_state())
282 .unwrap()
283 .rmag_km()
284 * 1e3
285 );
286
287 Ok(())
288}More examples
35fn main() -> Result<(), Box<dyn Error>> {
36 pel::init();
37
38 // ====================== //
39 // === ALMANAC SET UP === //
40 // ====================== //
41
42 // Dynamics models require planetary constants and ephemerides to be defined.
43 // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45 let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
46 .iter()
47 .collect();
48
49 let meta = data_folder.join("lro-dynamics.dhall");
50
51 // Load this ephem in the general Almanac we're using for this analysis.
52 let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
53 .map_err(Box::new)?
54 .process(true)
55 .map_err(Box::new)?;
56
57 let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
58 moon_pc.mu_km3_s2 = 4902.74987;
59 almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
60
61 let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
62 earth.mu_km3_s2 = 398600.436;
63 almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
64
65 // Save this new kernel for reuse.
66 // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
67 almanac
68 .planetary_data
69 .values()
70 .next()
71 .unwrap()
72 .save_as(&data_folder.join("lro-specific.pca"), true)?;
73
74 // Lock the almanac (an Arc is a read only structure).
75 let almanac = Arc::new(almanac);
76
77 // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
78 // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
79 // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
80 // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
81 let lro_frame = Frame::from_ephem_j2000(-85);
82
83 // To build the trajectory we need to provide a spacecraft template.
84 let sc_template = Spacecraft::builder()
85 .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
86 .srp(SRPData {
87 // SRP configuration is arbitrary, but we will be estimating it anyway.
88 area_m2: 3.9 * 2.7,
89 coeff_reflectivity: 0.96,
90 })
91 .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
92 .build();
93 // Now we can build the trajectory from the BSP file.
94 // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
95 let traj_as_flown = Traj::from_bsp(
96 lro_frame,
97 MOON_J2000,
98 almanac.clone(),
99 sc_template,
100 5.seconds(),
101 Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
102 Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
103 Aberration::LT,
104 Some("LRO".to_string()),
105 )?;
106
107 println!("{traj_as_flown}");
108
109 // ====================== //
110 // === MODEL MATCHING === //
111 // ====================== //
112
113 // Set up the spacecraft dynamics.
114
115 // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
116 // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
117 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
118
119 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
120 // We're using the GRAIL JGGRX model.
121 let mut jggrx_meta = MetaFile {
122 uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
123 crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
124 };
125 // And let's download it if we don't have it yet.
126 jggrx_meta.process(true)?;
127
128 // Build the spherical harmonics.
129 // The harmonics must be computed in the body fixed frame.
130 // We're using the long term prediction of the Moon principal axes frame.
131 let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
132 let sph_harmonics = Harmonics::from_stor(
133 almanac.frame_info(moon_pa_frame)?,
134 HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
135 );
136
137 // Include the spherical harmonics into the orbital dynamics.
138 orbital_dyn.accel_models.push(sph_harmonics);
139
140 // We define the solar radiation pressure, using the default solar flux and accounting only
141 // for the eclipsing caused by the Earth and Moon.
142 // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
143 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
144
145 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
146 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
147 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
148
149 println!("{dynamics}");
150
151 // Now we can build the propagator.
152 let setup = Propagator::default_dp78(dynamics.clone());
153
154 // For reference, let's build the trajectory with Nyx's models from that LRO state.
155 let (sim_final, traj_as_sim) = setup
156 .with(*traj_as_flown.first(), almanac.clone())
157 .until_epoch_with_traj(traj_as_flown.last().epoch())?;
158
159 println!("SIM INIT: {:x}", traj_as_flown.first());
160 println!("SIM FINAL: {sim_final:x}");
161 // Compute RIC difference between SIM and LRO ephem
162 let sim_lro_delta = sim_final
163 .orbit
164 .ric_difference(&traj_as_flown.last().orbit)?;
165 println!("{traj_as_sim}");
166 println!(
167 "SIM v LRO - RIC Position (m): {:.3}",
168 sim_lro_delta.radius_km * 1e3
169 );
170 println!(
171 "SIM v LRO - RIC Velocity (m/s): {:.3}",
172 sim_lro_delta.velocity_km_s * 1e3
173 );
174
175 traj_as_sim.ric_diff_to_parquet(
176 &traj_as_flown,
177 "./data/04_output/04_lro_sim_truth_error.parquet",
178 ExportCfg::default(),
179 )?;
180
181 // ==================== //
182 // === OD SIMULATOR === //
183 // ==================== //
184
185 // After quite some time trying to exactly match the model, we still end up with an oscillatory difference on the order of 150 meters between the propagated state
186 // and the truth LRO state.
187
188 // Therefore, we will actually run an estimation from a dispersed LRO state.
189 // The sc_seed is the true LRO state from the BSP.
190 let sc_seed = *traj_as_flown.first();
191
192 // Load the Deep Space Network ground stations.
193 // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
194 let ground_station_file: PathBuf = [
195 env!("CARGO_MANIFEST_DIR"),
196 "examples",
197 "04_lro_od",
198 "dsn-network.yaml",
199 ]
200 .iter()
201 .collect();
202
203 let devices = GroundStation::load_named(ground_station_file)?;
204
205 let mut proc_devices = devices.clone();
206
207 // Increase the noise in the devices to accept more measurements.
208 for gs in proc_devices.values_mut() {
209 if let Some(noise) = &mut gs
210 .stochastic_noises
211 .as_mut()
212 .unwrap()
213 .get_mut(&MeasurementType::Range)
214 {
215 *noise.white_noise.as_mut().unwrap() *= 3.0;
216 }
217 }
218
219 // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
220 // Nyx can build a tracking schedule for you based on the first station with access.
221 let trkconfg_yaml: PathBuf = [
222 env!("CARGO_MANIFEST_DIR"),
223 "examples",
224 "04_lro_od",
225 "tracking-cfg.yaml",
226 ]
227 .iter()
228 .collect();
229
230 let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
231
232 // Build the tracking arc simulation to generate a "standard measurement".
233 let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
234 devices.clone(),
235 traj_as_flown.clone(),
236 configs,
237 123, // Set a seed for reproducibility
238 )?;
239
240 trk.build_schedule(almanac.clone())?;
241 let arc = trk.generate_measurements(almanac.clone())?;
242 // Save the simulated tracking data
243 arc.to_parquet_simple("./data/04_output/04_lro_simulated_tracking.parquet")?;
244
245 // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
246 println!("{arc}");
247
248 // Now that we have simulated measurements, we'll run the orbit determination.
249
250 // ===================== //
251 // === OD ESTIMATION === //
252 // ===================== //
253
254 let sc = SpacecraftUncertainty::builder()
255 .nominal(sc_seed)
256 .frame(LocalFrame::RIC)
257 .x_km(0.5)
258 .y_km(0.5)
259 .z_km(0.5)
260 .vx_km_s(5e-3)
261 .vy_km_s(5e-3)
262 .vz_km_s(5e-3)
263 .build();
264
265 // Build the filter initial estimate, which we will reuse in the filter.
266 let mut initial_estimate = sc.to_estimate()?;
267 initial_estimate.covar *= 3.0;
268
269 println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
270
271 // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
272 let process_noise = ProcessNoise3D::from_velocity_km_s(
273 &[1e-10, 1e-10, 1e-10],
274 1 * Unit::Hour,
275 10 * Unit::Minute,
276 None,
277 );
278
279 println!("{process_noise}");
280
281 // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
282 let odp = SpacecraftKalmanOD::new(
283 setup,
284 KalmanVariant::ReferenceUpdate,
285 Some(ResidRejectCrit::default()),
286 proc_devices,
287 almanac.clone(),
288 )
289 .with_process_noise(process_noise);
290
291 let od_sol = odp.process_arc(initial_estimate, &arc)?;
292
293 let final_est = od_sol.estimates.last().unwrap();
294
295 println!("{final_est}");
296
297 let ric_err = traj_as_flown
298 .at(final_est.epoch())?
299 .orbit
300 .ric_difference(&final_est.orbital_state())?;
301 println!("== RIC at end ==");
302 println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
303 println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
304
305 println!(
306 "Num residuals rejected: #{}",
307 od_sol.rejected_residuals().len()
308 );
309 println!(
310 "Percentage within +/-3: {}",
311 od_sol.residual_ratio_within_threshold(3.0).unwrap()
312 );
313 println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
314
315 od_sol.to_parquet(
316 "./data/04_output/04_lro_od_results.parquet",
317 ExportCfg::default(),
318 )?;
319
320 // Create the ephemeris
321 let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
322 let ephem_start = ephem.start_epoch().unwrap();
323 let ephem_end = ephem.end_epoch().unwrap();
324 // Check that the covariance is PSD throughout the ephemeris by interpolating it.
325 for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
326 ephem
327 .covar_at(
328 epoch,
329 anise::ephemerides::ephemeris::LocalFrame::RIC,
330 &almanac,
331 )
332 .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
333 }
334 // Export as BSP!
335 ephem
336 .write_spice_bsp(-85, "./data/04_output/04_lro_rebuilt.bsp", None)
337 .expect("could not built BSP");
338 let new_almanac = Almanac::default()
339 .load("./data/04_output/04_lro_rebuilt.bsp")
340 .unwrap();
341 new_almanac.describe(None, None, None, None, None, None, None, None);
342 let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
343
344 assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
345 assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
346
347 // In our case, we have the truth trajectory from NASA.
348 // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
349 // Export the OD trajectory first.
350 let od_trajectory = od_sol.to_traj()?;
351 // Build the RIC difference.
352 od_trajectory.ric_diff_to_parquet(
353 &traj_as_flown,
354 "./data/04_output/04_lro_od_truth_error.parquet",
355 ExportCfg::default(),
356 )?;
357
358 Ok(())
359}pub fn describe(
&self,
spk: Option<bool>,
bpc: Option<bool>,
planetary: Option<bool>,
spacecraft: Option<bool>,
eulerparams: Option<bool>,
locations: Option<bool>,
time_scale: Option<TimeScale>,
round_time: Option<bool>,
)
pub fn describe( &self, spk: Option<bool>, bpc: Option<bool>, planetary: Option<bool>, spacecraft: Option<bool>, eulerparams: Option<bool>, locations: Option<bool>, time_scale: Option<TimeScale>, round_time: Option<bool>, )
Pretty prints the description of this Almanac, showing everything by default. Default time scale is TDB. If any parameter is set to true, then nothing other than that will be printed.
Examples found in repository?
35fn main() -> Result<(), Box<dyn Error>> {
36 pel::init();
37
38 // ====================== //
39 // === ALMANAC SET UP === //
40 // ====================== //
41
42 // Dynamics models require planetary constants and ephemerides to be defined.
43 // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45 let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
46 .iter()
47 .collect();
48
49 let meta = data_folder.join("lro-dynamics.dhall");
50
51 // Load this ephem in the general Almanac we're using for this analysis.
52 let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
53 .map_err(Box::new)?
54 .process(true)
55 .map_err(Box::new)?;
56
57 let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
58 moon_pc.mu_km3_s2 = 4902.74987;
59 almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
60
61 let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
62 earth.mu_km3_s2 = 398600.436;
63 almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
64
65 // Save this new kernel for reuse.
66 // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
67 almanac
68 .planetary_data
69 .values()
70 .next()
71 .unwrap()
72 .save_as(&data_folder.join("lro-specific.pca"), true)?;
73
74 // Lock the almanac (an Arc is a read only structure).
75 let almanac = Arc::new(almanac);
76
77 // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
78 // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
79 // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
80 // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
81 let lro_frame = Frame::from_ephem_j2000(-85);
82
83 // To build the trajectory we need to provide a spacecraft template.
84 let sc_template = Spacecraft::builder()
85 .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
86 .srp(SRPData {
87 // SRP configuration is arbitrary, but we will be estimating it anyway.
88 area_m2: 3.9 * 2.7,
89 coeff_reflectivity: 0.96,
90 })
91 .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
92 .build();
93 // Now we can build the trajectory from the BSP file.
94 // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
95 let traj_as_flown = Traj::from_bsp(
96 lro_frame,
97 MOON_J2000,
98 almanac.clone(),
99 sc_template,
100 5.seconds(),
101 Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
102 Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
103 Aberration::LT,
104 Some("LRO".to_string()),
105 )?;
106
107 println!("{traj_as_flown}");
108
109 // ====================== //
110 // === MODEL MATCHING === //
111 // ====================== //
112
113 // Set up the spacecraft dynamics.
114
115 // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
116 // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
117 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
118
119 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
120 // We're using the GRAIL JGGRX model.
121 let mut jggrx_meta = MetaFile {
122 uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
123 crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
124 };
125 // And let's download it if we don't have it yet.
126 jggrx_meta.process(true)?;
127
128 // Build the spherical harmonics.
129 // The harmonics must be computed in the body fixed frame.
130 // We're using the long term prediction of the Moon principal axes frame.
131 let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
132 let sph_harmonics = Harmonics::from_stor(
133 almanac.frame_info(moon_pa_frame)?,
134 HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
135 );
136
137 // Include the spherical harmonics into the orbital dynamics.
138 orbital_dyn.accel_models.push(sph_harmonics);
139
140 // We define the solar radiation pressure, using the default solar flux and accounting only
141 // for the eclipsing caused by the Earth and Moon.
142 // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
143 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
144
145 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
146 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
147 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
148
149 println!("{dynamics}");
150
151 // Now we can build the propagator.
152 let setup = Propagator::default_dp78(dynamics.clone());
153
154 // For reference, let's build the trajectory with Nyx's models from that LRO state.
155 let (sim_final, traj_as_sim) = setup
156 .with(*traj_as_flown.first(), almanac.clone())
157 .until_epoch_with_traj(traj_as_flown.last().epoch())?;
158
159 println!("SIM INIT: {:x}", traj_as_flown.first());
160 println!("SIM FINAL: {sim_final:x}");
161 // Compute RIC difference between SIM and LRO ephem
162 let sim_lro_delta = sim_final
163 .orbit
164 .ric_difference(&traj_as_flown.last().orbit)?;
165 println!("{traj_as_sim}");
166 println!(
167 "SIM v LRO - RIC Position (m): {:.3}",
168 sim_lro_delta.radius_km * 1e3
169 );
170 println!(
171 "SIM v LRO - RIC Velocity (m/s): {:.3}",
172 sim_lro_delta.velocity_km_s * 1e3
173 );
174
175 traj_as_sim.ric_diff_to_parquet(
176 &traj_as_flown,
177 "./data/04_output/04_lro_sim_truth_error.parquet",
178 ExportCfg::default(),
179 )?;
180
181 // ==================== //
182 // === OD SIMULATOR === //
183 // ==================== //
184
185 // After quite some time trying to exactly match the model, we still end up with an oscillatory difference on the order of 150 meters between the propagated state
186 // and the truth LRO state.
187
188 // Therefore, we will actually run an estimation from a dispersed LRO state.
189 // The sc_seed is the true LRO state from the BSP.
190 let sc_seed = *traj_as_flown.first();
191
192 // Load the Deep Space Network ground stations.
193 // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
194 let ground_station_file: PathBuf = [
195 env!("CARGO_MANIFEST_DIR"),
196 "examples",
197 "04_lro_od",
198 "dsn-network.yaml",
199 ]
200 .iter()
201 .collect();
202
203 let devices = GroundStation::load_named(ground_station_file)?;
204
205 let mut proc_devices = devices.clone();
206
207 // Increase the noise in the devices to accept more measurements.
208 for gs in proc_devices.values_mut() {
209 if let Some(noise) = &mut gs
210 .stochastic_noises
211 .as_mut()
212 .unwrap()
213 .get_mut(&MeasurementType::Range)
214 {
215 *noise.white_noise.as_mut().unwrap() *= 3.0;
216 }
217 }
218
219 // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
220 // Nyx can build a tracking schedule for you based on the first station with access.
221 let trkconfg_yaml: PathBuf = [
222 env!("CARGO_MANIFEST_DIR"),
223 "examples",
224 "04_lro_od",
225 "tracking-cfg.yaml",
226 ]
227 .iter()
228 .collect();
229
230 let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
231
232 // Build the tracking arc simulation to generate a "standard measurement".
233 let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
234 devices.clone(),
235 traj_as_flown.clone(),
236 configs,
237 123, // Set a seed for reproducibility
238 )?;
239
240 trk.build_schedule(almanac.clone())?;
241 let arc = trk.generate_measurements(almanac.clone())?;
242 // Save the simulated tracking data
243 arc.to_parquet_simple("./data/04_output/04_lro_simulated_tracking.parquet")?;
244
245 // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
246 println!("{arc}");
247
248 // Now that we have simulated measurements, we'll run the orbit determination.
249
250 // ===================== //
251 // === OD ESTIMATION === //
252 // ===================== //
253
254 let sc = SpacecraftUncertainty::builder()
255 .nominal(sc_seed)
256 .frame(LocalFrame::RIC)
257 .x_km(0.5)
258 .y_km(0.5)
259 .z_km(0.5)
260 .vx_km_s(5e-3)
261 .vy_km_s(5e-3)
262 .vz_km_s(5e-3)
263 .build();
264
265 // Build the filter initial estimate, which we will reuse in the filter.
266 let mut initial_estimate = sc.to_estimate()?;
267 initial_estimate.covar *= 3.0;
268
269 println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
270
271 // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
272 let process_noise = ProcessNoise3D::from_velocity_km_s(
273 &[1e-10, 1e-10, 1e-10],
274 1 * Unit::Hour,
275 10 * Unit::Minute,
276 None,
277 );
278
279 println!("{process_noise}");
280
281 // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
282 let odp = SpacecraftKalmanOD::new(
283 setup,
284 KalmanVariant::ReferenceUpdate,
285 Some(ResidRejectCrit::default()),
286 proc_devices,
287 almanac.clone(),
288 )
289 .with_process_noise(process_noise);
290
291 let od_sol = odp.process_arc(initial_estimate, &arc)?;
292
293 let final_est = od_sol.estimates.last().unwrap();
294
295 println!("{final_est}");
296
297 let ric_err = traj_as_flown
298 .at(final_est.epoch())?
299 .orbit
300 .ric_difference(&final_est.orbital_state())?;
301 println!("== RIC at end ==");
302 println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
303 println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
304
305 println!(
306 "Num residuals rejected: #{}",
307 od_sol.rejected_residuals().len()
308 );
309 println!(
310 "Percentage within +/-3: {}",
311 od_sol.residual_ratio_within_threshold(3.0).unwrap()
312 );
313 println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
314
315 od_sol.to_parquet(
316 "./data/04_output/04_lro_od_results.parquet",
317 ExportCfg::default(),
318 )?;
319
320 // Create the ephemeris
321 let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
322 let ephem_start = ephem.start_epoch().unwrap();
323 let ephem_end = ephem.end_epoch().unwrap();
324 // Check that the covariance is PSD throughout the ephemeris by interpolating it.
325 for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
326 ephem
327 .covar_at(
328 epoch,
329 anise::ephemerides::ephemeris::LocalFrame::RIC,
330 &almanac,
331 )
332 .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
333 }
334 // Export as BSP!
335 ephem
336 .write_spice_bsp(-85, "./data/04_output/04_lro_rebuilt.bsp", None)
337 .expect("could not built BSP");
338 let new_almanac = Almanac::default()
339 .load("./data/04_output/04_lro_rebuilt.bsp")
340 .unwrap();
341 new_almanac.describe(None, None, None, None, None, None, None, None);
342 let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
343
344 assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
345 assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
346
347 // In our case, we have the truth trajectory from NASA.
348 // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
349 // Export the OD trajectory first.
350 let od_trajectory = od_sol.to_traj()?;
351 // Build the RIC difference.
352 od_trajectory.ric_diff_to_parquet(
353 &traj_as_flown,
354 "./data/04_output/04_lro_od_truth_error.parquet",
355 ExportCfg::default(),
356 )?;
357
358 Ok(())
359}pub fn list_kernels(
&self,
spk: Option<bool>,
bpc: Option<bool>,
planetary: Option<bool>,
spacecraft: Option<bool>,
eulerparams: Option<bool>,
locations: Option<bool>,
) -> Vec<String>
pub fn list_kernels( &self, spk: Option<bool>, bpc: Option<bool>, planetary: Option<bool>, spacecraft: Option<bool>, eulerparams: Option<bool>, locations: Option<bool>, ) -> Vec<String>
Returns the list of loaded kernels
pub fn set_crc32(&mut self)
pub fn set_crc32(&mut self)
Set the CRC32 of all loaded DAF files
pub fn spk_swap(
&mut self,
alias: &str,
new_spk_path: &str,
new_alias: String,
) -> Result<(), AlmanacError>
pub fn spk_swap( &mut self, alias: &str, new_spk_path: &str, new_alias: String, ) -> Result<(), AlmanacError>
Load a new DAF/SPK file in place of the one in the provided alias.
This reuses the existing memory buffer, growing it only if the new file is larger than the previous capacity. This effectively adopts a “high watermark” memory strategy, where the memory usage for this slot is determined by the largest file ever loaded into it.
pub fn bpc_swap(
&mut self,
alias: &str,
new_bpc_path: &str,
new_alias: String,
) -> Result<(), AlmanacError>
pub fn bpc_swap( &mut self, alias: &str, new_bpc_path: &str, new_alias: String, ) -> Result<(), AlmanacError>
Load a new DAF/BPC file in place of the one in the provided alias.
This reuses the existing memory buffer, growing it only if the new file is larger than the previous capacity. This effectively adopts a “high watermark” memory strategy, where the memory usage for this slot is determined by the largest file ever loaded into it.
§impl Almanac
impl Almanac
pub fn report_events<S>(
&self,
state_spec: &S,
event: &Event,
start_epoch: Epoch,
end_epoch: Epoch,
) -> Result<Vec<EventDetails>, AnalysisError>where
S: StateSpecTrait,
pub fn report_events<S>(
&self,
state_spec: &S,
event: &Event,
start_epoch: Epoch,
end_epoch: Epoch,
) -> Result<Vec<EventDetails>, AnalysisError>where
S: StateSpecTrait,
Report all of the states when the provided event happens. This method may only be used for equality events, minimum, and maximum events. For spanned events (e.g. Less Than/Greater Than), use report_event_arcs.
§Method
The report event function starts by lineraly scanning the whole state spec from the start to the end epoch. This uses an adaptive step scan modeled on the Runge Kutta adaptive step integrator, but the objective is to ensure that the scalar expression of the event is evaluated at steps where it is linearly changing (to within 10% of linearity). This allows finding coarse brackets where the expression changes signs exactly once. Then, each bracket it sent in parallel to a Brent’s method root finder to find the exact time of the event.
§Limitation
While this approach is both very robust and very fast, if you think the finder may be missing some events, you should reduce the epoch precision of the event as a multiplicative factor of that precision is used to scan the trajectory linearly. Alternatively, you may export the scalars at a fixed interval using the report_scalars or report_scalars_flat function and manually analyze the results of the scalar expression.
pub fn report_event_arcs<S>(
&self,
state_spec: &S,
event: &Event,
start_epoch: Epoch,
end_epoch: Epoch,
) -> Result<Vec<EventArc>, AnalysisError>where
S: StateSpecTrait,
pub fn report_event_arcs<S>(
&self,
state_spec: &S,
event: &Event,
start_epoch: Epoch,
end_epoch: Epoch,
) -> Result<Vec<EventArc>, AnalysisError>where
S: StateSpecTrait,
Report the rising and falling edges/states where the event arc happens.
For example, for a scalar expression less than X, this will report all of the times when the expression falls below X and rises above X. This method uses the report_events function under the hood.
pub fn report_visibility_arcs<S>(
&self,
state_spec: &S,
location_id: i32,
start_epoch: Epoch,
end_epoch: Epoch,
sample_rate: Duration,
obstructing_body: Option<Frame>,
) -> Result<Vec<VisibilityArc>, AnalysisError>where
S: StateSpecTrait,
pub fn report_visibility_arcs<S>(
&self,
state_spec: &S,
location_id: i32,
start_epoch: Epoch,
end_epoch: Epoch,
sample_rate: Duration,
obstructing_body: Option<Frame>,
) -> Result<Vec<VisibilityArc>, AnalysisError>where
S: StateSpecTrait,
Report the list of visibility arcs for the desired location ID.
§impl Almanac
impl Almanac
pub fn report_scalars<S>(
&self,
report: &ReportScalars<S>,
time_series: TimeSeries,
) -> HashMap<Epoch, Result<HashMap<String, Result<f64, AnalysisError>>, AnalysisError>>where
S: StateSpecTrait,
pub fn report_scalars<S>(
&self,
report: &ReportScalars<S>,
time_series: TimeSeries,
) -> HashMap<Epoch, Result<HashMap<String, Result<f64, AnalysisError>>, AnalysisError>>where
S: StateSpecTrait,
Report a set of scalar expressions, optionally with aliases, at a fixed time step defined in the TimeSeries.
pub fn report_scalars_flat<S>(
&self,
report: &ReportScalars<S>,
time_series: TimeSeries,
) -> Result<ScalarsTable, AnalysisError>where
S: StateSpecTrait,
pub fn report_scalars_flat<S>(
&self,
report: &ReportScalars<S>,
time_series: TimeSeries,
) -> Result<ScalarsTable, AnalysisError>where
S: StateSpecTrait,
Report a set of scalar expressions, optionally with aliases, at a fixed time step defined in the TimeSeries, as a flat table that can be serialized in columnal form.
§impl Almanac
impl Almanac
pub fn build_ephemeris(
&self,
target_frame: Frame,
observer_frame: Frame,
time_series: TimeSeries,
ab_corr: Option<Aberration>,
object_id: String,
) -> Ephemeris
pub fn build_ephemeris( &self, target_frame: Frame, observer_frame: Frame, time_series: TimeSeries, ab_corr: Option<Aberration>, object_id: String, ) -> Ephemeris
Builds the ephemeris of the target seen from the observer with the provided aberration throughout the time series.
§impl Almanac
impl Almanac
pub fn try_find_ephemeris_root(&self) -> Result<i32, EphemerisError>
pub fn try_find_ephemeris_root(&self) -> Result<i32, EphemerisError>
Returns the root of all of the loaded ephemerides, typically this should be the Solar System Barycenter.
§Algorithm
- For each loaded SPK, iterated in reverse order (to mimic SPICE behavior)
- For each summary record in each SPK, follow the ephemeris branch all the way up until the end of this SPK or until the SSB.
pub fn ephemeris_path_to_root(
&self,
source: Frame,
epoch: Epoch,
) -> Result<(usize, [Option<i32>; 8]), EphemerisError>
pub fn ephemeris_path_to_root( &self, source: Frame, epoch: Epoch, ) -> Result<(usize, [Option<i32>; 8]), EphemerisError>
Try to construct the path from the source frame all the way to the root ephemeris of this context.
pub fn common_ephemeris_path(
&self,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
) -> Result<(usize, [Option<i32>; 8], i32), EphemerisError>
pub fn common_ephemeris_path( &self, from_frame: Frame, to_frame: Frame, epoch: Epoch, ) -> Result<(usize, [Option<i32>; 8], i32), EphemerisError>
Returns the ephemeris path between two frames and the common node. This may return a DisjointRoots error if the frames do not share a common root, which is considered a file integrity error.
§Example
If the “from” frame is Earth Barycenter whose path to the ANISE root is the following:
Solar System barycenter
╰─> Earth Moon Barycenter
╰─> EarthAnd the “to” frame is Moon, whose path is:
Solar System barycenter
╰─> Earth Moon Barycenter
╰─> Moon
╰─> LROThen this function will return the path an array of hashes of up to [MAX_TREE_DEPTH] items. In this example, the array with the hashes of the “Earth Moon Barycenter” and “Moon”.
§Note
A proper ANISE file should only have a single root and if two paths are empty, then they should be the same frame. If a DisjointRoots error is reported here, it means that the ANISE file is invalid.
§Time complexity
This can likely be simplified as this as a time complexity of O(n×m) where n, m are the lengths of the paths from the ephemeris up to the root. This can probably be optimized to avoid rewinding the entire frame path up to the root frame
§impl Almanac
impl Almanac
pub fn translate_to_parent(
&self,
source: Frame,
epoch: Epoch,
) -> Result<CartesianState, EphemerisError>
pub fn translate_to_parent( &self, source: Frame, epoch: Epoch, ) -> Result<CartesianState, EphemerisError>
Performs the GEOMETRIC translation to the parent. Use translate_from_to for aberration.
:type source: Frame :type epoch: Epoch :rtype: Orbit
§impl Almanac
impl Almanac
pub fn translate(
&self,
target_frame: Frame,
observer_frame: Frame,
epoch: Epoch,
ab_corr: Option<Aberration>,
) -> Result<CartesianState, EphemerisError>
pub fn translate( &self, target_frame: Frame, observer_frame: Frame, epoch: Epoch, ab_corr: Option<Aberration>, ) -> Result<CartesianState, EphemerisError>
Returns the Cartesian state of the target frame as seen from the observer frame at the provided epoch, and optionally given the aberration correction.
§SPICE Compatibility
This function is the SPICE equivalent of spkezr: spkezr(TARGET_ID, EPOCH_TDB_S, ORIENTATION_ID, ABERRATION, OBSERVER_ID)
In ANISE, the TARGET_ID and ORIENTATION are provided in the first argument (TARGET_FRAME), as that frame includes BOTH
the target ID and the orientation of that target. The EPOCH_TDB_S is the epoch in the TDB time system, which is computed
in ANISE using Hifitime. THe ABERRATION is computed by providing the optional Aberration flag. Finally, the OBSERVER
argument is replaced by OBSERVER_FRAME: if the OBSERVER_FRAME argument has the same orientation as the TARGET_FRAME, then this call
will return exactly the same data as the spkerz SPICE call.
§Warning
This function only performs the translation and no rotation whatsoever. Use the transform function instead to include rotations.
§Note
This function performs a recursion of no more than twice the [MAX_TREE_DEPTH].
§Algorithm
- Find the common ancestor of the
target_frameandobserver_framein the ephemeris tree usingcommon_ephemeris_path. - Initialize the state vectors for both the forward (observer to common ancestor) and backward (target to common ancestor) paths.
- Iteratively traverse the ephemeris tree from the observer and target frames up to the common ancestor, accumulating the state vectors at each step using
translation_parts_to_parent. - If aberration corrections are requested, calculate the one-way light time and apply the correction to the target’s position.
- The final state is the difference between the backward and forward state vectors.
pub fn translate_geometric(
&self,
target_frame: Frame,
observer_frame: Frame,
epoch: Epoch,
) -> Result<CartesianState, EphemerisError>
pub fn translate_geometric( &self, target_frame: Frame, observer_frame: Frame, epoch: Epoch, ) -> Result<CartesianState, EphemerisError>
Returns the geometric position vector, velocity vector, and acceleration vector needed to translate the from_frame to the to_frame, where the distance is in km, the velocity in km/s, and the acceleration in km/s^2.
pub fn translate_to(
&self,
state: CartesianState,
observer_frame: Frame,
ab_corr: Option<Aberration>,
) -> Result<CartesianState, EphemerisError>
pub fn translate_to( &self, state: CartesianState, observer_frame: Frame, ab_corr: Option<Aberration>, ) -> Result<CartesianState, EphemerisError>
Translates the provided Cartesian state into the requested observer frame
WARNING: This function only performs the translation and no rotation whatsoever. Use the transform_to function instead to include rotations.
pub fn translate_state_to(
&self,
position: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>,
velocity: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>,
from_frame: Frame,
observer_frame: Frame,
epoch: Epoch,
ab_corr: Option<Aberration>,
distance_unit: LengthUnit,
time_unit: Unit,
) -> Result<CartesianState, EphemerisError>
pub fn translate_state_to( &self, position: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, velocity: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, from_frame: Frame, observer_frame: Frame, epoch: Epoch, ab_corr: Option<Aberration>, distance_unit: LengthUnit, time_unit: Unit, ) -> Result<CartesianState, EphemerisError>
Translates a state with its origin (to_frame) and given its units (distance_unit, time_unit), returns that state with respect to the requested frame
WARNING: This function only performs the translation and no rotation whatsoever. Use the transform_state_to function instead to include rotations.
§impl Almanac
impl Almanac
pub fn try_find_orientation_root(&self) -> Result<i32, OrientationError>
pub fn try_find_orientation_root(&self) -> Result<i32, OrientationError>
Returns the root of all of the loaded orientations (BPC or planetary), typically this should be J2000.
§Algorithm
- For each loaded BPC, iterated in reverse order (to mimic SPICE behavior)
- For each summary record in each BPC, follow the orientation branch all the way up until the end of this BPC or until the J2000.
pub fn orientation_path_to_root(
&self,
source: Frame,
epoch: Epoch,
) -> Result<(usize, [Option<i32>; 8]), OrientationError>
pub fn orientation_path_to_root( &self, source: Frame, epoch: Epoch, ) -> Result<(usize, [Option<i32>; 8]), OrientationError>
Try to construct the path from the source frame all the way to the root orientation of this context.
pub fn common_orientation_path(
&self,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
) -> Result<(usize, [Option<i32>; 8], i32), OrientationError>
pub fn common_orientation_path( &self, from_frame: Frame, to_frame: Frame, epoch: Epoch, ) -> Result<(usize, [Option<i32>; 8], i32), OrientationError>
Returns the orientation path between two frames and the common node. This may return a DisjointRoots error if the frames do not share a common root, which is considered a file integrity error.
§impl Almanac
impl Almanac
pub fn rotation_to_parent(
&self,
source: Frame,
epoch: Epoch,
) -> Result<DCM, OrientationError>
pub fn rotation_to_parent( &self, source: Frame, epoch: Epoch, ) -> Result<DCM, OrientationError>
Returns the direct cosine matrix (DCM) to rotate from the source to its parent in the orientation hierarchy at the provided epoch,
§Example
If the ephemeris stores position interpolation coefficients in kilometer but this function is called with millimeters as a distance unit, the output vectors will be in mm, mm/s, mm/s^2 respectively.
§Errors
- As of now, some interpolation types are not supported, and if that were to happen, this would return an error.
WARNING: This function only performs the rotation and no translation whatsoever. Use the transform_to_parent_from function instead to include rotations.
§impl Almanac
impl Almanac
pub fn rotate(
&self,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
) -> Result<DCM, OrientationError>
pub fn rotate( &self, from_frame: Frame, to_frame: Frame, epoch: Epoch, ) -> Result<DCM, OrientationError>
Returns the 6x6 DCM needed to rotation the from_frame to the to_frame.
§Warning
This function only performs the rotation and no translation whatsoever. Use the transform_from_to function instead to include rotations.
§Note
This function performs a recursion of no more than twice the MAX_TREE_DEPTH.
§Algorithm
- Find the common ancestor of the
from_frameandto_framein the orientation tree usingcommon_orientation_path. - Initialize the DCMs for both the forward (from to common ancestor) and backward (to to common ancestor) paths.
- Iteratively traverse the orientation tree from the
fromandtoframes up to the common ancestor, composing the DCMs at each step usingrotation_to_parent. - The final DCM is the composition of the forward and backward DCMs.
pub fn rotate_to(
&self,
state: CartesianState,
observer_frame: Frame,
) -> Result<CartesianState, OrientationError>
pub fn rotate_to( &self, state: CartesianState, observer_frame: Frame, ) -> Result<CartesianState, OrientationError>
Rotates the provided Cartesian state into the requested observer frame
WARNING: This function only performs the translation and no rotation whatsoever. Use the transform_to function instead to include rotations.
pub fn angular_velocity_rad_s(
&self,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
pub fn angular_velocity_rad_s( &self, from_frame: Frame, to_frame: Frame, epoch: Epoch, ) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
Returns the angular velocity vector in rad/s of the from_frame wrt to the to_frame.
This can be used to compute the angular velocity of the Earth ITRF93 frame with respect to the J2000 frame for example.
pub fn angular_velocity_wrt_j2000_rad_s(
&self,
from_frame: Frame,
epoch: Epoch,
) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
pub fn angular_velocity_wrt_j2000_rad_s( &self, from_frame: Frame, epoch: Epoch, ) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
Returns the angular velocity vector in rad/s of the from_frame wrt to the J2000 frame.
pub fn angular_velocity_deg_s(
&self,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
pub fn angular_velocity_deg_s( &self, from_frame: Frame, to_frame: Frame, epoch: Epoch, ) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
Returns the angular velocity vector in deg/s of the from_frame wrt to the to_frame.
This can be used to compute the angular velocity of the Earth ITRF93 frame with respect to the J2000 frame for example.
pub fn angular_velocity_wrt_j2000_deg_s(
&self,
from_frame: Frame,
epoch: Epoch,
) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
pub fn angular_velocity_wrt_j2000_deg_s( &self, from_frame: Frame, epoch: Epoch, ) -> Result<Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, OrientationError>
Returns the angular velocity vector in deg/s of the from_frame wrt to the J2000 frame.
pub fn rotate_state_to(
&self,
position: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>,
velocity: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
distance_unit: LengthUnit,
time_unit: Unit,
) -> Result<CartesianState, OrientationError>
pub fn rotate_state_to( &self, position: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, velocity: Matrix<f64, Const<3>, Const<1>, ArrayStorage<f64, 3, 1>>, from_frame: Frame, to_frame: Frame, epoch: Epoch, distance_unit: LengthUnit, time_unit: Unit, ) -> Result<CartesianState, OrientationError>
Rotates a state with its origin (to_frame) and given its units (distance_unit, time_unit), returns that state with respect to the requested frame
WARNING: This function only performs the translation and no rotation whatsoever. Use the transform_state_to function instead to include rotations.
Trait Implementations§
Auto Trait Implementations§
impl Freeze for Almanac
impl RefUnwindSafe for Almanac
impl Send for Almanac
impl Sync for Almanac
impl Unpin for Almanac
impl UnwindSafe for Almanac
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
§impl<T> Instrument for T
impl<T> Instrument for T
§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left is true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left(&self) returns true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read more§impl<T> Pointable for T
impl<T> Pointable for T
§impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
§fn to_subset(&self) -> Option<SS>
fn to_subset(&self) -> Option<SS>
self from the equivalent element of its
superset. Read more§fn is_in_subset(&self) -> bool
fn is_in_subset(&self) -> bool
self is actually part of its subset T (and can be converted to it).§fn to_subset_unchecked(&self) -> SS
fn to_subset_unchecked(&self) -> SS
self.to_subset but without any property checks. Always succeeds.§fn from_subset(element: &SS) -> SP
fn from_subset(element: &SS) -> SP
self to the equivalent element of its superset.