Struct Almanac
pub struct Almanac {
pub spk_data: [Option<GenericDAF<SPKSummaryRecord, Bytes>>; 32],
pub bpc_data: [Option<GenericDAF<BPCSummaryRecord, Bytes>>; 8],
pub planetary_data: DataSet<PlanetaryData, anise::::structure::PlanetaryDataSet::{constant#0}>,
pub spacecraft_data: DataSet<SpacecraftData, anise::::structure::SpacecraftDataSet::{constant#0}>,
pub euler_param_data: DataSet<EulerParameter, anise::::structure::EulerParameterDataSet::{constant#0}>,
}
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: [Option<GenericDAF<SPKSummaryRecord, Bytes>>; 32]
NAIF SPK is kept unchanged
bpc_data: [Option<GenericDAF<BPCSummaryRecord, Bytes>>; 8]
NAIF BPC is kept unchanged
planetary_data: DataSet<PlanetaryData, anise::::structure::PlanetaryDataSet::{constant#0}>
Dataset of planetary data
spacecraft_data: DataSet<SpacecraftData, anise::::structure::SpacecraftDataSet::{constant#0}>
Dataset of spacecraft data
euler_param_data: DataSet<EulerParameter, anise::::structure::EulerParameterDataSet::{constant#0}>
Dataset of euler parameters
Implementations§
§impl Almanac
impl Almanac
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.
:type rx: Orbit :type tx: Orbit :type obstructing_body: Frame, optional :type ab_corr: Aberration, optional :rtype: AzElRange
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_from_uid(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_from_uid(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 almanac.clone(),
190 )?;
191
192 // 2. Compare the difference in the radial-intrack-crosstrack frame between the high fidelity
193 // and Keplerian propagation. The RIC frame is commonly used to compute the difference in position
194 // and velocity of different spacecraft.
195 // 3. Compute the azimuth, elevation, range, and range-rate data of that spacecraft as seen from Boulder, CO, USA.
196
197 let boulder_station = GroundStation::from_point(
198 "Boulder, CO, USA".to_string(),
199 40.014984, // latitude in degrees
200 -105.270546, // longitude in degrees
201 1.6550, // altitude in kilometers
202 almanac.frame_from_uid(IAU_EARTH_FRAME)?,
203 );
204
205 // We iterate over the trajectory, grabbing a state every two minutes.
206 let mut offset_s = vec![];
207 let mut epoch_str = vec![];
208 let mut ric_x_km = vec![];
209 let mut ric_y_km = vec![];
210 let mut ric_z_km = vec![];
211 let mut ric_vx_km_s = vec![];
212 let mut ric_vy_km_s = vec![];
213 let mut ric_vz_km_s = vec![];
214
215 let mut azimuth_deg = vec![];
216 let mut elevation_deg = vec![];
217 let mut range_km = vec![];
218 let mut range_rate_km_s = vec![];
219 for state in trajectory.every(Unit::Minute * 2) {
220 // Try to compute the Keplerian/two body state just in time.
221 // This method occasionally fails to converge on an appropriate true anomaly
222 // from the mean anomaly. If that happens, we just skip this state.
223 // The high fidelity and Keplerian states diverge continuously, and we're curious
224 // about the divergence in this quick analysis.
225 let this_epoch = state.epoch();
226 match orbit.at_epoch(this_epoch) {
227 Ok(tb_then) => {
228 offset_s.push((this_epoch - orbit.epoch).to_seconds());
229 epoch_str.push(format!("{this_epoch}"));
230 // Compute the two body state just in time.
231 let ric = state.orbit.ric_difference(&tb_then)?;
232 ric_x_km.push(ric.radius_km.x);
233 ric_y_km.push(ric.radius_km.y);
234 ric_z_km.push(ric.radius_km.z);
235 ric_vx_km_s.push(ric.velocity_km_s.x);
236 ric_vy_km_s.push(ric.velocity_km_s.y);
237 ric_vz_km_s.push(ric.velocity_km_s.z);
238
239 // Compute the AER data for each state.
240 let aer = almanac.azimuth_elevation_range_sez(
241 state.orbit,
242 boulder_station.to_orbit(this_epoch, &almanac)?,
243 None,
244 None,
245 )?;
246 azimuth_deg.push(aer.azimuth_deg);
247 elevation_deg.push(aer.elevation_deg);
248 range_km.push(aer.range_km);
249 range_rate_km_s.push(aer.range_rate_km_s);
250 }
251 Err(e) => warn!("{} {e}", state.epoch()),
252 };
253 }
254
255 // Build the data frames.
256 let ric_df = df!(
257 "Offset (s)" => offset_s.clone(),
258 "Epoch" => epoch_str.clone(),
259 "RIC X (km)" => ric_x_km,
260 "RIC Y (km)" => ric_y_km,
261 "RIC Z (km)" => ric_z_km,
262 "RIC VX (km/s)" => ric_vx_km_s,
263 "RIC VY (km/s)" => ric_vy_km_s,
264 "RIC VZ (km/s)" => ric_vz_km_s,
265 )?;
266
267 println!("RIC difference at start\n{}", ric_df.head(Some(10)));
268 println!("RIC difference at end\n{}", ric_df.tail(Some(10)));
269
270 let aer_df = df!(
271 "Offset (s)" => offset_s.clone(),
272 "Epoch" => epoch_str.clone(),
273 "azimuth (deg)" => azimuth_deg,
274 "elevation (deg)" => elevation_deg,
275 "range (km)" => range_km,
276 "range rate (km/s)" => range_rate_km_s,
277 )?;
278
279 // Finally, let's see when the spacecraft is visible, assuming 15 degrees minimum elevation.
280 let mask = aer_df
281 .column("elevation (deg)")?
282 .gt(&Column::Scalar(ScalarColumn::new(
283 "elevation mask (deg)".into(),
284 Scalar::new(DataType::Float64, AnyValue::Float64(15.0)),
285 offset_s.len(),
286 )))?;
287 let cubesat_visible = aer_df.filter(&mask)?;
288
289 println!("{cubesat_visible}");
290
291 Ok(())
292}
§impl Almanac
impl Almanac
pub fn from_bpc( bpc: GenericDAF<BPCSummaryRecord, Bytes>, ) -> Result<Almanac, OrientationError>
pub fn with_bpc(
&self,
bpc: GenericDAF<BPCSummaryRecord, Bytes>,
) -> Result<Almanac, OrientationError>
pub fn with_bpc( &self, bpc: GenericDAF<BPCSummaryRecord, Bytes>, ) -> Result<Almanac, OrientationError>
Loads a Binary Planetary Constants kernel.
pub fn num_loaded_bpc(&self) -> usize
pub fn bpc_summary_from_name_at_epoch(
&self,
name: &str,
epoch: Epoch,
) -> Result<(&BPCSummaryRecord, usize, usize), OrientationError>
pub fn bpc_summary_from_name_at_epoch( &self, name: &str, epoch: Epoch, ) -> Result<(&BPCSummaryRecord, 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, usize), OrientationError>
pub fn bpc_summary_at_epoch( &self, id: i32, epoch: Epoch, ) -> Result<(&BPCSummaryRecord, usize, usize), OrientationError>
Returns the summary given the name of the summary record if that summary has data defined at the requested epoch
pub fn bpc_summary_from_name(
&self,
name: &str,
) -> Result<(&BPCSummaryRecord, usize, usize), OrientationError>
pub fn bpc_summary_from_name( &self, name: &str, ) -> Result<(&BPCSummaryRecord, usize, usize), OrientationError>
Returns the summary given the name of the summary record.
pub fn bpc_summary(
&self,
id: i32,
) -> Result<(&BPCSummaryRecord, usize, usize), OrientationError>
pub fn bpc_summary( &self, id: i32, ) -> Result<(&BPCSummaryRecord, 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:
o
represents 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.):
r1
andr2
are the transformed radii of the observed and observer objects, respectively.r1sq
andr2sq
are the squared magnitudes of these vectors.r1dotr2
is the dot product ofr1
andr2
.tau
is 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^2
checks if the line of sight is within the obstructing body’s radius, indicating an obstruction.
:type observer: Orbit :type observed: Orbit :type obstructing_body: Frame :type ab_corr: Aberration, optional :rtype: bool
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.
:type back_frame: Frame :type front_frame: Frame :type observer: Orbit :type ab_corr: Aberration, optional :rtype: Occultation
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
§impl Almanac
impl Almanac
pub fn frame_from_uid<U>(&self, uid: U) -> Result<Frame, PlanetaryDataError>
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
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_from_uid(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(StateParameter::SMA, 42_164.0, 5.0), // 5 km
58 Objective::within_tolerance(StateParameter::Eccentricity, 0.001, 5e-5),
59 Objective::within_tolerance(StateParameter::Inclination, 0.05, 1e-2),
60 ];
61
62 let ruggiero_ctrl = Ruggiero::from_max_eclipse(objectives, sc, 0.2)?;
63 println!("{ruggiero_ctrl}");
64
65 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
66
67 let mut jgm3_meta = MetaFile {
68 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
69 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
70 };
71 jgm3_meta.process(true)?;
72
73 let harmonics = Harmonics::from_stor(
74 almanac.frame_from_uid(IAU_EARTH_FRAME)?,
75 HarmonicsMem::from_cof(&jgm3_meta.uri, 8, 8, true)?,
76 );
77 orbital_dyn.accel_models.push(harmonics);
78
79 let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
80 let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
81 .with_guidance_law(ruggiero_ctrl.clone());
82
83 println!("{sc_dynamics}");
84
85 // Finally, let's use the Monte Carlo framework built into Nyx to propagate spacecraft.
86
87 // Let's start by defining the dispersion.
88 // 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.
89 // Note that additional validation on the MVN is in progress -- https://github.com/nyx-space/nyx/issues/339.
90 let mc_rv = MvnSpacecraft::new(
91 sc,
92 vec![StateDispersion::zero_mean(StateParameter::SMA, 3.0)],
93 )?;
94
95 let my_mc = MonteCarlo::new(
96 sc, // Nominal state
97 mc_rv,
98 "03_geo_sk".to_string(), // Scenario name
99 None, // No specific seed specified, so one will be drawn from the computer's entropy.
100 );
101
102 // Build the propagator setup.
103 let setup = Propagator::rk89(
104 sc_dynamics.clone(),
105 IntegratorOptions::builder()
106 .min_step(10.0_f64.seconds())
107 .error_ctrl(ErrorControl::RSSCartesianStep)
108 .build(),
109 );
110
111 let num_runs = 25;
112 let rslts = my_mc.run_until_epoch(setup, almanac.clone(), sc.epoch() + prop_time, num_runs);
113
114 assert_eq!(rslts.runs.len(), num_runs);
115
116 // For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
117
118 rslts.to_parquet(
119 "03_geo_sk.parquet",
120 Some(vec![
121 &EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
122 ]),
123 ExportCfg::default(),
124 almanac,
125 )?;
126
127 Ok(())
128}
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_from_uid(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(StateParameter::SMA, 42_165.0, 20.0),
69 Objective::within_tolerance(StateParameter::Eccentricity, 0.001, 5e-5),
70 Objective::within_tolerance(StateParameter::Inclination, 0.05, 1e-2),
71 ];
72
73 // Ensure that we only thrust if we have more than 20% illumination.
74 let ruggiero_ctrl = Ruggiero::from_max_eclipse(objectives, sc, 0.2).unwrap();
75 println!("{ruggiero_ctrl}");
76
77 // Define the high fidelity dynamics
78
79 // Set up the spacecraft dynamics.
80
81 // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
82 // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
83 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
84
85 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
86 // We're using the JGM3 model here, which is the default in GMAT.
87 let mut jgm3_meta = MetaFile {
88 uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
89 crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
90 };
91 // And let's download it if we don't have it yet.
92 jgm3_meta.process(true)?;
93
94 // Build the spherical harmonics.
95 // The harmonics must be computed in the body fixed frame.
96 // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
97 let harmonics = Harmonics::from_stor(
98 almanac.frame_from_uid(IAU_EARTH_FRAME)?,
99 HarmonicsMem::from_cof(&jgm3_meta.uri, 8, 8, true).unwrap(),
100 );
101
102 // Include the spherical harmonics into the orbital dynamics.
103 orbital_dyn.accel_models.push(harmonics);
104
105 // We define the solar radiation pressure, using the default solar flux and accounting only
106 // for the eclipsing caused by the Earth.
107 let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
108
109 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
110 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
111 let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
112 .with_guidance_law(ruggiero_ctrl.clone());
113
114 println!("{:x}", orbit);
115
116 // We specify a minimum step in the propagator because the Ruggiero control would otherwise drive this step very low.
117 let (final_state, traj) = Propagator::rk89(
118 sc_dynamics.clone(),
119 IntegratorOptions::builder()
120 .min_step(10.0_f64.seconds())
121 .error_ctrl(ErrorControl::RSSCartesianStep)
122 .build(),
123 )
124 .with(sc, almanac.clone())
125 .for_duration_with_traj(prop_time)?;
126
127 let prop_usage = sc.mass.prop_mass_kg - final_state.mass.prop_mass_kg;
128 println!("{:x}", final_state.orbit);
129 println!("prop usage: {:.3} kg", prop_usage);
130
131 // Finally, export the results for analysis, including the penumbra percentage throughout the orbit raise.
132 traj.to_parquet(
133 "./03_geo_raise.parquet",
134 Some(vec![
135 &EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
136 ]),
137 ExportCfg::default(),
138 almanac,
139 )?;
140
141 for status_line in ruggiero_ctrl.status(&final_state) {
142 println!("{status_line}");
143 }
144
145 ruggiero_ctrl
146 .achieved(&final_state)
147 .expect("objective not achieved");
148
149 Ok(())
150}
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_from_uid(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_from_uid(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 Some(vec![
155 &EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
156 ]),
157 ExportCfg::builder().step(analysis_step).build(),
158 almanac.clone(),
159 )?;
160
161 // 2. Compute the latitude, longitude, and altitude throughout the trajectory by rotating the spacecraft position into the Earth body fixed frame.
162
163 // We iterate over the trajectory, grabbing a state every two minutes.
164 let mut offset_s = vec![];
165 let mut epoch_str = vec![];
166 let mut longitude_deg = vec![];
167 let mut latitude_deg = vec![];
168 let mut altitude_km = vec![];
169
170 for state in trajectory.every(analysis_step) {
171 // Convert the GEO bird state into the body fixed frame, and keep track of its latitude, longitude, and altitude.
172 // These define the GEO stationkeeping box.
173
174 let this_epoch = state.epoch();
175
176 offset_s.push((this_epoch - orbit.epoch).to_seconds());
177 epoch_str.push(this_epoch.to_isoformat());
178
179 let state_bf = almanac.transform_to(state.orbit, IAU_EARTH_FRAME, None)?;
180 let (lat_deg, long_deg, alt_km) = state_bf.latlongalt()?;
181 longitude_deg.push(long_deg);
182 latitude_deg.push(lat_deg);
183 altitude_km.push(alt_km);
184 }
185
186 println!(
187 "Longitude changed by {:.3} deg -- Box is 0.1 deg E-W",
188 orig_long_deg - longitude_deg.last().unwrap()
189 );
190
191 println!(
192 "Latitude changed by {:.3} deg -- Box is 0.05 deg N-S",
193 orig_lat_deg - latitude_deg.last().unwrap()
194 );
195
196 println!(
197 "Altitude changed by {:.3} km -- Box is 30 km",
198 orig_alt_km - altitude_km.last().unwrap()
199 );
200
201 // Build the station keeping data frame.
202 let mut sk_df = df!(
203 "Offset (s)" => offset_s.clone(),
204 "Epoch (UTC)" => epoch_str.clone(),
205 "Longitude E-W (deg)" => longitude_deg,
206 "Latitude N-S (deg)" => latitude_deg,
207 "Altitude (km)" => altitude_km,
208
209 )?;
210
211 // Create a file to write the Parquet to
212 let file = File::create("./03_geo_lla.parquet").expect("Could not create file");
213
214 // Create a ParquetWriter and write the DataFrame to the file
215 ParquetWriter::new(file).finish(&mut sk_df)?;
216
217 Ok(())
218}
33fn main() -> Result<(), Box<dyn Error>> {
34 pel::init();
35
36 // ====================== //
37 // === ALMANAC SET UP === //
38 // ====================== //
39
40 // Dynamics models require planetary constants and ephemerides to be defined.
41 // Let's start by grabbing those by using ANISE's MetaAlmanac.
42
43 let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
44 .iter()
45 .collect();
46
47 let meta = data_folder.join("lro-dynamics.dhall");
48
49 // Load this ephem in the general Almanac we're using for this analysis.
50 let mut almanac = MetaAlmanac::new(meta.to_string_lossy().to_string())
51 .map_err(Box::new)?
52 .process(true)
53 .map_err(Box::new)?;
54
55 let mut moon_pc = almanac.planetary_data.get_by_id(MOON)?;
56 moon_pc.mu_km3_s2 = 4902.74987;
57 almanac.planetary_data.set_by_id(MOON, moon_pc)?;
58
59 let mut earth_pc = almanac.planetary_data.get_by_id(EARTH)?;
60 earth_pc.mu_km3_s2 = 398600.436;
61 almanac.planetary_data.set_by_id(EARTH, earth_pc)?;
62
63 // Save this new kernel for reuse.
64 // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
65 almanac
66 .planetary_data
67 .save_as(&data_folder.join("lro-specific.pca"), true)?;
68
69 // Lock the almanac (an Arc is a read only structure).
70 let almanac = Arc::new(almanac);
71
72 // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
73 // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
74 // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
75 // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
76 let lro_frame = Frame::from_ephem_j2000(-85);
77
78 // To build the trajectory we need to provide a spacecraft template.
79 let sc_template = Spacecraft::builder()
80 .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
81 .srp(SRPData {
82 // SRP configuration is arbitrary, but we will be estimating it anyway.
83 area_m2: 3.9 * 2.7,
84 coeff_reflectivity: 0.96,
85 })
86 .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
87 .build();
88 // Now we can build the trajectory from the BSP file.
89 // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
90 let traj_as_flown = Traj::from_bsp(
91 lro_frame,
92 MOON_J2000,
93 almanac.clone(),
94 sc_template,
95 5.seconds(),
96 Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
97 Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
98 Aberration::LT,
99 Some("LRO".to_string()),
100 )?;
101
102 println!("{traj_as_flown}");
103
104 // ====================== //
105 // === MODEL MATCHING === //
106 // ====================== //
107
108 // Set up the spacecraft dynamics.
109
110 // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
111 // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
112 let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
113
114 // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
115 // We're using the GRAIL JGGRX model.
116 let mut jggrx_meta = MetaFile {
117 uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
118 crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
119 };
120 // And let's download it if we don't have it yet.
121 jggrx_meta.process(true)?;
122
123 // Build the spherical harmonics.
124 // The harmonics must be computed in the body fixed frame.
125 // We're using the long term prediction of the Moon principal axes frame.
126 let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
127 let sph_harmonics = Harmonics::from_stor(
128 almanac.frame_from_uid(moon_pa_frame)?,
129 HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
130 );
131
132 // Include the spherical harmonics into the orbital dynamics.
133 orbital_dyn.accel_models.push(sph_harmonics);
134
135 // We define the solar radiation pressure, using the default solar flux and accounting only
136 // for the eclipsing caused by the Earth and Moon.
137 // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
138 let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
139
140 // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
141 // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
142 let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
143
144 println!("{dynamics}");
145
146 // Now we can build the propagator.
147 let setup = Propagator::default_dp78(dynamics.clone());
148
149 // For reference, let's build the trajectory with Nyx's models from that LRO state.
150 let (sim_final, traj_as_sim) = setup
151 .with(*traj_as_flown.first(), almanac.clone())
152 .until_epoch_with_traj(traj_as_flown.last().epoch())?;
153
154 println!("SIM INIT: {:x}", traj_as_flown.first());
155 println!("SIM FINAL: {sim_final:x}");
156 // Compute RIC difference between SIM and LRO ephem
157 let sim_lro_delta = sim_final
158 .orbit
159 .ric_difference(&traj_as_flown.last().orbit)?;
160 println!("{traj_as_sim}");
161 println!(
162 "SIM v LRO - RIC Position (m): {:.3}",
163 sim_lro_delta.radius_km * 1e3
164 );
165 println!(
166 "SIM v LRO - RIC Velocity (m/s): {:.3}",
167 sim_lro_delta.velocity_km_s * 1e3
168 );
169
170 traj_as_sim.ric_diff_to_parquet(
171 &traj_as_flown,
172 "./04_lro_sim_truth_error.parquet",
173 ExportCfg::default(),
174 )?;
175
176 // ==================== //
177 // === OD SIMULATOR === //
178 // ==================== //
179
180 // 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
181 // and the truth LRO state.
182
183 // Therefore, we will actually run an estimation from a dispersed LRO state.
184 // The sc_seed is the true LRO state from the BSP.
185 let sc_seed = *traj_as_flown.first();
186
187 // Load the Deep Space Network ground stations.
188 // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
189 let ground_station_file: PathBuf = [
190 env!("CARGO_MANIFEST_DIR"),
191 "examples",
192 "04_lro_od",
193 "dsn-network.yaml",
194 ]
195 .iter()
196 .collect();
197
198 let devices = GroundStation::load_named(ground_station_file)?;
199
200 // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
201 // Nyx can build a tracking schedule for you based on the first station with access.
202 let trkconfg_yaml: PathBuf = [
203 env!("CARGO_MANIFEST_DIR"),
204 "examples",
205 "04_lro_od",
206 "tracking-cfg.yaml",
207 ]
208 .iter()
209 .collect();
210
211 let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
212
213 // Build the tracking arc simulation to generate a "standard measurement".
214 let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::new(
215 devices.clone(),
216 traj_as_flown.clone(),
217 configs,
218 )?;
219
220 trk.build_schedule(almanac.clone())?;
221 let arc = trk.generate_measurements(almanac.clone())?;
222 // Save the simulated tracking data
223 arc.to_parquet_simple("./04_lro_simulated_tracking.parquet")?;
224
225 // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
226 println!("{arc}");
227
228 // Now that we have simulated measurements, we'll run the orbit determination.
229
230 // ===================== //
231 // === OD ESTIMATION === //
232 // ===================== //
233
234 let sc = SpacecraftUncertainty::builder()
235 .nominal(sc_seed)
236 .frame(LocalFrame::RIC)
237 .x_km(0.5)
238 .y_km(0.5)
239 .z_km(0.5)
240 .vx_km_s(5e-3)
241 .vy_km_s(5e-3)
242 .vz_km_s(5e-3)
243 .build();
244
245 // Build the filter initial estimate, which we will reuse in the filter.
246 let initial_estimate = sc.to_estimate()?;
247
248 println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
249
250 let kf = KF::new(
251 // Increase the initial covariance to account for larger deviation.
252 initial_estimate,
253 // Until https://github.com/nyx-space/nyx/issues/351, we need to specify the SNC in the acceleration of the Moon J2000 frame.
254 SNC3::from_diagonal(10 * Unit::Minute, &[1e-12, 1e-12, 1e-12]),
255 );
256
257 // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
258 let mut odp = SpacecraftODProcess::ckf(
259 setup.with(initial_estimate.state().with_stm(), almanac.clone()),
260 kf,
261 devices,
262 Some(ResidRejectCrit::default()),
263 almanac.clone(),
264 );
265
266 odp.process_arc(&arc)?;
267
268 let ric_err = traj_as_flown
269 .at(odp.estimates.last().unwrap().epoch())?
270 .orbit
271 .ric_difference(&odp.estimates.last().unwrap().orbital_state())?;
272 println!("== RIC at end ==");
273 println!("RIC Position (m): {}", ric_err.radius_km * 1e3);
274 println!("RIC Velocity (m/s): {}", ric_err.velocity_km_s * 1e3);
275
276 odp.to_parquet(&arc, "./04_lro_od_results.parquet", ExportCfg::default())?;
277
278 // In our case, we have the truth trajectory from NASA.
279 // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
280 // Export the OD trajectory first.
281 let od_trajectory = odp.to_traj()?;
282 // Build the RIC difference.
283 od_trajectory.ric_diff_to_parquet(
284 &traj_as_flown,
285 "./04_lro_od_truth_error.parquet",
286 ExportCfg::default(),
287 )?;
288
289 Ok(())
290}
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_from_uid(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_from_uid(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 almanac.clone(),
190 )?;
191
192 // 2. Compare the difference in the radial-intrack-crosstrack frame between the high fidelity
193 // and Keplerian propagation. The RIC frame is commonly used to compute the difference in position
194 // and velocity of different spacecraft.
195 // 3. Compute the azimuth, elevation, range, and range-rate data of that spacecraft as seen from Boulder, CO, USA.
196
197 let boulder_station = GroundStation::from_point(
198 "Boulder, CO, USA".to_string(),
199 40.014984, // latitude in degrees
200 -105.270546, // longitude in degrees
201 1.6550, // altitude in kilometers
202 almanac.frame_from_uid(IAU_EARTH_FRAME)?,
203 );
204
205 // We iterate over the trajectory, grabbing a state every two minutes.
206 let mut offset_s = vec![];
207 let mut epoch_str = vec![];
208 let mut ric_x_km = vec![];
209 let mut ric_y_km = vec![];
210 let mut ric_z_km = vec![];
211 let mut ric_vx_km_s = vec![];
212 let mut ric_vy_km_s = vec![];
213 let mut ric_vz_km_s = vec![];
214
215 let mut azimuth_deg = vec![];
216 let mut elevation_deg = vec![];
217 let mut range_km = vec![];
218 let mut range_rate_km_s = vec![];
219 for state in trajectory.every(Unit::Minute * 2) {
220 // Try to compute the Keplerian/two body state just in time.
221 // This method occasionally fails to converge on an appropriate true anomaly
222 // from the mean anomaly. If that happens, we just skip this state.
223 // The high fidelity and Keplerian states diverge continuously, and we're curious
224 // about the divergence in this quick analysis.
225 let this_epoch = state.epoch();
226 match orbit.at_epoch(this_epoch) {
227 Ok(tb_then) => {
228 offset_s.push((this_epoch - orbit.epoch).to_seconds());
229 epoch_str.push(format!("{this_epoch}"));
230 // Compute the two body state just in time.
231 let ric = state.orbit.ric_difference(&tb_then)?;
232 ric_x_km.push(ric.radius_km.x);
233 ric_y_km.push(ric.radius_km.y);
234 ric_z_km.push(ric.radius_km.z);
235 ric_vx_km_s.push(ric.velocity_km_s.x);
236 ric_vy_km_s.push(ric.velocity_km_s.y);
237 ric_vz_km_s.push(ric.velocity_km_s.z);
238
239 // Compute the AER data for each state.
240 let aer = almanac.azimuth_elevation_range_sez(
241 state.orbit,
242 boulder_station.to_orbit(this_epoch, &almanac)?,
243 None,
244 None,
245 )?;
246 azimuth_deg.push(aer.azimuth_deg);
247 elevation_deg.push(aer.elevation_deg);
248 range_km.push(aer.range_km);
249 range_rate_km_s.push(aer.range_rate_km_s);
250 }
251 Err(e) => warn!("{} {e}", state.epoch()),
252 };
253 }
254
255 // Build the data frames.
256 let ric_df = df!(
257 "Offset (s)" => offset_s.clone(),
258 "Epoch" => epoch_str.clone(),
259 "RIC X (km)" => ric_x_km,
260 "RIC Y (km)" => ric_y_km,
261 "RIC Z (km)" => ric_z_km,
262 "RIC VX (km/s)" => ric_vx_km_s,
263 "RIC VY (km/s)" => ric_vy_km_s,
264 "RIC VZ (km/s)" => ric_vz_km_s,
265 )?;
266
267 println!("RIC difference at start\n{}", ric_df.head(Some(10)));
268 println!("RIC difference at end\n{}", ric_df.tail(Some(10)));
269
270 let aer_df = df!(
271 "Offset (s)" => offset_s.clone(),
272 "Epoch" => epoch_str.clone(),
273 "azimuth (deg)" => azimuth_deg,
274 "elevation (deg)" => elevation_deg,
275 "range (km)" => range_km,
276 "range rate (km/s)" => range_rate_km_s,
277 )?;
278
279 // Finally, let's see when the spacecraft is visible, assuming 15 degrees minimum elevation.
280 let mask = aer_df
281 .column("elevation (deg)")?
282 .gt(&Column::Scalar(ScalarColumn::new(
283 "elevation mask (deg)".into(),
284 Scalar::new(DataType::Float64, AnyValue::Float64(15.0)),
285 offset_s.len(),
286 )))?;
287 let cubesat_visible = aer_df.filter(&mask)?;
288
289 println!("{cubesat_visible}");
290
291 Ok(())
292}
pub fn with_planetary_data(
&self,
planetary_data: DataSet<PlanetaryData, anise::::structure::PlanetaryDataSet::{constant#0}>,
) -> Almanac
pub fn with_planetary_data( &self, planetary_data: DataSet<PlanetaryData, anise::::structure::PlanetaryDataSet::{constant#0}>, ) -> Almanac
Loads the provided planetary data into a clone of this original Almanac.
§impl Almanac
impl Almanac
pub fn sun_angle_deg(
&self,
target_id: i32,
observer_id: i32,
epoch: Epoch,
) -> Result<f64, EphemerisError>
pub fn sun_angle_deg( &self, target_id: i32, observer_id: i32, epoch: Epoch, ) -> Result<f64, EphemerisError>
Returns the angle (between 0 and 180 degrees) between the observer and the Sun, and the observer and the target body ID. 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.
§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 :rtype: float
§impl Almanac
impl Almanac
pub fn from_spk( spk: GenericDAF<SPKSummaryRecord, Bytes>, ) -> Result<Almanac, EphemerisError>
pub fn with_spk(
&self,
spk: GenericDAF<SPKSummaryRecord, Bytes>,
) -> Result<Almanac, EphemerisError>
pub fn with_spk( &self, spk: GenericDAF<SPKSummaryRecord, Bytes>, ) -> Result<Almanac, EphemerisError>
Loads a new SPK file into a new context. 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.
§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, usize), EphemerisError>
pub fn spk_summary_from_name_at_epoch( &self, name: &str, epoch: Epoch, ) -> Result<(&SPKSummaryRecord, 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, usize), EphemerisError>
pub fn spk_summary_at_epoch( &self, id: i32, epoch: Epoch, ) -> Result<(&SPKSummaryRecord, usize, usize), EphemerisError>
Returns the summary given the name of the summary record if that summary has data defined at the requested epoch
pub fn spk_summary_from_name(
&self,
name: &str,
) -> Result<(&SPKSummaryRecord, usize, usize), EphemerisError>
pub fn spk_summary_from_name( &self, name: &str, ) -> Result<(&SPKSummaryRecord, usize, usize), EphemerisError>
Returns the most recently loaded summary by its name, if any with that ID are available
pub fn spk_summary(
&self,
id: i32,
) -> Result<(&SPKSummaryRecord, usize, usize), EphemerisError>
pub fn spk_summary( &self, id: i32, ) -> Result<(&SPKSummaryRecord, usize, usize), EphemerisError>
Returns the most recently loaded summary by its ID, if any with that ID are available
§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 OD process, and predicting for the analysis duration.
114
115 let ckf = KF::no_snc(jwst_estimate);
116
117 // Build the propagation instance for the OD process.
118 let prop = setup.with(jwst.with_stm(), almanac.clone());
119 let mut odp = SpacecraftODProcess::ckf(prop, ckf, BTreeMap::new(), None, almanac.clone());
120
121 // Define the prediction step, i.e. how often we want to know the covariance.
122 let step = 1_i64.minutes();
123 // Finally, predict, and export the trajectory with covariance to a parquet file.
124 odp.predict_for(step, prediction_duration)?;
125 odp.to_parquet(
126 &TrackingDataArc::default(),
127 "./02_jwst_covar_map.parquet",
128 ExportCfg::default(),
129 )?;
130
131 // === Monte Carlo framework ===
132 // Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
133
134 let my_mc = MonteCarlo::new(
135 jwst, // Nominal state
136 jwst_estimate.to_random_variable()?,
137 "02_jwst".to_string(), // Scenario name
138 None, // No specific seed specified, so one will be drawn from the computer's entropy.
139 );
140
141 let num_runs = 5_000;
142 let rslts = my_mc.run_until_epoch(
143 setup,
144 almanac.clone(),
145 jwst.epoch() + prediction_duration,
146 num_runs,
147 );
148
149 assert_eq!(rslts.runs.len(), num_runs);
150 // Finally, export these results, computing the eclipse percentage for all of these results.
151
152 // For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
153 let eclipse_loc = EclipseLocator::cislunar(almanac.clone());
154 let umbra_event = eclipse_loc.to_umbra_event();
155 let penumbra_event = eclipse_loc.to_penumbra_event();
156
157 rslts.to_parquet(
158 "02_jwst_monte_carlo.parquet",
159 Some(vec![&umbra_event, &penumbra_event]),
160 ExportCfg::default(),
161 almanac,
162 )?;
163
164 Ok(())
165}
§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 from_frame
to the to_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)
:type target_frame: Orbit :type observer_frame: Frame :type epoch: Epoch :type ab_corr: Aberration, optional :rtype: Orbit
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 OD process, and predicting for the analysis duration.
114
115 let ckf = KF::no_snc(jwst_estimate);
116
117 // Build the propagation instance for the OD process.
118 let prop = setup.with(jwst.with_stm(), almanac.clone());
119 let mut odp = SpacecraftODProcess::ckf(prop, ckf, BTreeMap::new(), None, almanac.clone());
120
121 // Define the prediction step, i.e. how often we want to know the covariance.
122 let step = 1_i64.minutes();
123 // Finally, predict, and export the trajectory with covariance to a parquet file.
124 odp.predict_for(step, prediction_duration)?;
125 odp.to_parquet(
126 &TrackingDataArc::default(),
127 "./02_jwst_covar_map.parquet",
128 ExportCfg::default(),
129 )?;
130
131 // === Monte Carlo framework ===
132 // Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
133
134 let my_mc = MonteCarlo::new(
135 jwst, // Nominal state
136 jwst_estimate.to_random_variable()?,
137 "02_jwst".to_string(), // Scenario name
138 None, // No specific seed specified, so one will be drawn from the computer's entropy.
139 );
140
141 let num_runs = 5_000;
142 let rslts = my_mc.run_until_epoch(
143 setup,
144 almanac.clone(),
145 jwst.epoch() + prediction_duration,
146 num_runs,
147 );
148
149 assert_eq!(rslts.runs.len(), num_runs);
150 // Finally, export these results, computing the eclipse percentage for all of these results.
151
152 // For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
153 let eclipse_loc = EclipseLocator::cislunar(almanac.clone());
154 let umbra_event = eclipse_loc.to_umbra_event();
155 let penumbra_event = eclipse_loc.to_penumbra_event();
156
157 rslts.to_parquet(
158 "02_jwst_monte_carlo.parquet",
159 Some(vec![&umbra_event, &penumbra_event]),
160 ExportCfg::default(),
161 almanac,
162 )?;
163
164 Ok(())
165}
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>
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.
:type state: Orbit :type observer_frame: Frame :type ab_corr: Aberration, optional :rtype: Orbit
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 // 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_from_uid(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_from_uid(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 Some(vec![
155 &EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
156 ]),
157 ExportCfg::builder().step(analysis_step).build(),
158 almanac.clone(),
159 )?;
160
161 // 2. Compute the latitude, longitude, and altitude throughout the trajectory by rotating the spacecraft position into the Earth body fixed frame.
162
163 // We iterate over the trajectory, grabbing a state every two minutes.
164 let mut offset_s = vec![];
165 let mut epoch_str = vec![];
166 let mut longitude_deg = vec![];
167 let mut latitude_deg = vec![];
168 let mut altitude_km = vec![];
169
170 for state in trajectory.every(analysis_step) {
171 // Convert the GEO bird state into the body fixed frame, and keep track of its latitude, longitude, and altitude.
172 // These define the GEO stationkeeping box.
173
174 let this_epoch = state.epoch();
175
176 offset_s.push((this_epoch - orbit.epoch).to_seconds());
177 epoch_str.push(this_epoch.to_isoformat());
178
179 let state_bf = almanac.transform_to(state.orbit, IAU_EARTH_FRAME, None)?;
180 let (lat_deg, long_deg, alt_km) = state_bf.latlongalt()?;
181 longitude_deg.push(long_deg);
182 latitude_deg.push(lat_deg);
183 altitude_km.push(alt_km);
184 }
185
186 println!(
187 "Longitude changed by {:.3} deg -- Box is 0.1 deg E-W",
188 orig_long_deg - longitude_deg.last().unwrap()
189 );
190
191 println!(
192 "Latitude changed by {:.3} deg -- Box is 0.05 deg N-S",
193 orig_lat_deg - latitude_deg.last().unwrap()
194 );
195
196 println!(
197 "Altitude changed by {:.3} km -- Box is 30 km",
198 orig_alt_km - altitude_km.last().unwrap()
199 );
200
201 // Build the station keeping data frame.
202 let mut sk_df = df!(
203 "Offset (s)" => offset_s.clone(),
204 "Epoch (UTC)" => epoch_str.clone(),
205 "Longitude E-W (deg)" => longitude_deg,
206 "Latitude N-S (deg)" => latitude_deg,
207 "Altitude (km)" => altitude_km,
208
209 )?;
210
211 // Create a file to write the Parquet to
212 let file = File::create("./03_geo_lla.parquet").expect("Could not create file");
213
214 // Create a ParquetWriter and write the DataFrame to the file
215 ParquetWriter::new(file).finish(&mut sk_df)?;
216
217 Ok(())
218}
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)
:type object: int :type observer: Frame :type epoch: Epoch :type ab_corr: Aberration, optional :rtype: Orbit
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.
:type target: int :type epoch: Epoch :type frame: int :type observer: int :type ab_corr: Aberration, optional :rtype: Orbit
§impl Almanac
impl Almanac
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.
§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 OD process, and predicting for the analysis duration.
114
115 let ckf = KF::no_snc(jwst_estimate);
116
117 // Build the propagation instance for the OD process.
118 let prop = setup.with(jwst.with_stm(), almanac.clone());
119 let mut odp = SpacecraftODProcess::ckf(prop, ckf, BTreeMap::new(), None, almanac.clone());
120
121 // Define the prediction step, i.e. how often we want to know the covariance.
122 let step = 1_i64.minutes();
123 // Finally, predict, and export the trajectory with covariance to a parquet file.
124 odp.predict_for(step, prediction_duration)?;
125 odp.to_parquet(
126 &TrackingDataArc::default(),
127 "./02_jwst_covar_map.parquet",
128 ExportCfg::default(),
129 )?;
130
131 // === Monte Carlo framework ===
132 // Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
133
134 let my_mc = MonteCarlo::new(
135 jwst, // Nominal state
136 jwst_estimate.to_random_variable()?,
137 "02_jwst".to_string(), // Scenario name
138 None, // No specific seed specified, so one will be drawn from the computer's entropy.
139 );
140
141 let num_runs = 5_000;
142 let rslts = my_mc.run_until_epoch(
143 setup,
144 almanac.clone(),
145 jwst.epoch() + prediction_duration,
146 num_runs,
147 );
148
149 assert_eq!(rslts.runs.len(), num_runs);
150 // Finally, export these results, computing the eclipse percentage for all of these results.
151
152 // For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
153 let eclipse_loc = EclipseLocator::cislunar(almanac.clone());
154 let umbra_event = eclipse_loc.to_umbra_event();
155 let penumbra_event = eclipse_loc.to_penumbra_event();
156
157 rslts.to_parquet(
158 "02_jwst_monte_carlo.parquet",
159 Some(vec![&umbra_event, &penumbra_event]),
160 ExportCfg::default(),
161 almanac,
162 )?;
163
164 Ok(())
165}
§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
pub fn with_spacecraft_data(
&self,
spacecraft_data: DataSet<SpacecraftData, anise::::structure::SpacecraftDataSet::{constant#0}>,
) -> Almanac
pub fn with_spacecraft_data( &self, spacecraft_data: DataSet<SpacecraftData, anise::::structure::SpacecraftDataSet::{constant#0}>, ) -> Almanac
Loads the provided spacecraft data into a clone of this original Almanac.
pub fn with_euler_parameters(
&self,
ep_dataset: DataSet<EulerParameter, anise::::structure::EulerParameterDataSet::{constant#0}>,
) -> Almanac
pub fn with_euler_parameters( &self, ep_dataset: DataSet<EulerParameter, anise::::structure::EulerParameterDataSet::{constant#0}>, ) -> Almanac
Loads the provided Euler parameter data into a clone of this original Almanac.
pub fn load_from_bytes(&self, bytes: Bytes) -> Result<Almanac, AlmanacError>
pub fn load_from_bytes(&self, bytes: Bytes) -> Result<Almanac, AlmanacError>
Loads the provides bytes as one of the data types supported in ANISE.
§impl Almanac
impl Almanac
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.
:type path: str :rtype: Almanac
pub fn describe(
&self,
spk: Option<bool>,
bpc: Option<bool>,
planetary: Option<bool>,
eulerparams: Option<bool>,
time_scale: Option<TimeScale>,
round_time: Option<bool>,
)
pub fn describe( &self, spk: Option<bool>, bpc: Option<bool>, planetary: Option<bool>, eulerparams: 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.
:type spk: bool, optional :type bpc: bool, optional :type planetary: bool, optional :type time_scale: TimeScale, optional :type round_time: bool, optional :rtype: None
§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
╰─> Earth
And the “to” frame is Moon, whose path is:
Solar System barycenter
╰─> Earth Moon Barycenter
╰─> Moon
╰─> LRO
Then 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].
:type target_frame: Orbit :type observer_frame: Frame :type epoch: Epoch :type ab_corr: Aberration, optional :rtype: Orbit
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.
:type target_frame: Orbit :type observer_frame: Frame :type epoch: Epoch :rtype: Orbit
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.
:type state: Orbit :type observer_frame: Frame :type ab_corr: Aberration, optional :rtype: Orbit
§impl Almanac
impl Almanac
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>
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.
§impl Almanac
impl Almanac
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§
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T: ?Sized,
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T: Clone,
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T: Clone,
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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>
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into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
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§impl<SS, SP> SupersetOf<SS> for SPwhere
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impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
§fn to_subset(&self) -> Option<SS>
fn to_subset(&self) -> Option<SS>
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from the equivalent element of its
superset. Read more§fn is_in_subset(&self) -> bool
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is actually part of its subset T
(and can be converted to it).§fn to_subset_unchecked(&self) -> SS
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but without any property checks. Always succeeds.§fn from_subset(element: &SS) -> SP
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to the equivalent element of its superset.