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.
§Limitations
The stack space required depends on the maximum number of each type that can be loaded.
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,
) -> Result<AzElRange, AlmanacError>
pub fn azimuth_elevation_range_sez( &self, rx: CartesianState, tx: CartesianState, ) -> 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.
§Algorithm
- Compute the SEZ (South East Zenith) frame of the transmitter.
- Rotate the receiver position vector into the transmitter SEZ frame.
- Rotate the transmitter position vector into that same SEZ frame.
- Compute the range as the norm of the difference between these two position vectors.
- Compute the elevation, and ensure it is between +/- 180 degrees.
- Compute the azimuth with a quadrant check, and ensure it is between 0 and 360 degrees.
Examples found in repository?
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// This will automatically download the DE440s planetary ephemeris,
// the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
// parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
// planetary constants kernels.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
// references to many functions.
let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
// Define the orbit epoch
let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
// Define the orbit.
// First we need to fetch the Earth J2000 from information from the Almanac.
// This allows the frame to include the gravitational parameters and the shape of the Earth,
// defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
// by loading a different set of planetary constants.
let earth_j2000 = almanac.frame_from_uid(EARTH_J2000)?;
let orbit =
Orbit::try_keplerian_altitude(300.0, 0.015, 68.5, 65.2, 75.0, 0.0, epoch, earth_j2000)?;
// Print in in Keplerian form.
println!("{orbit:x}");
// There are two ways to propagate an orbit. We can make a quick approximation assuming only two-body
// motion. This is a useful first order approximation but it isn't used in real-world applications.
// This approach is a feature of ANISE.
let future_orbit_tb = orbit.at_epoch(epoch + Unit::Day * 3)?;
println!("{future_orbit_tb:x}");
// Two body propagation relies solely on Kepler's laws, so only the true anomaly will change.
println!(
"SMA changed by {:.3e} km",
orbit.sma_km()? - future_orbit_tb.sma_km()?
);
println!(
"ECC changed by {:.3e}",
orbit.ecc()? - future_orbit_tb.ecc()?
);
println!(
"INC changed by {:.3e} deg",
orbit.inc_deg()? - future_orbit_tb.inc_deg()?
);
println!(
"RAAN changed by {:.3e} deg",
orbit.raan_deg()? - future_orbit_tb.raan_deg()?
);
println!(
"AOP changed by {:.3e} deg",
orbit.aop_deg()? - future_orbit_tb.aop_deg()?
);
println!(
"TA changed by {:.3} deg",
orbit.ta_deg()? - future_orbit_tb.ta_deg()?
);
// Nyx is used for high fidelity propagation, not Keplerian propagation as above.
// Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
// models such as solar radiation pressure.
// Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
let sc = Spacecraft::builder()
.orbit(orbit)
.dry_mass_kg(9.60)
.srp(SrpConfig {
area_m2: 10e-4,
cr: 1.1,
})
.build();
println!("{sc:x}");
// Set up the spacecraft dynamics.
// Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
// The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
// We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
// We're using the JGM3 model here, which is the default in GMAT.
let mut jgm3_meta = MetaFile {
uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
};
// And let's download it if we don't have it yet.
jgm3_meta.process()?;
// Build the spherical harmonics.
// The harmonics must be computed in the body fixed frame.
// We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
let harmonics_21x21 = Harmonics::from_stor(
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
);
// Include the spherical harmonics into the orbital dynamics.
orbital_dyn.accel_models.push(harmonics_21x21);
// We define the solar radiation pressure, using the default solar flux and accounting only
// for the eclipsing caused by the Earth.
let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
// Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
// acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
println!("{dynamics}");
// Finally, let's propagate this orbit to the same epoch as above.
// The first returned value is the spacecraft state at the final epoch.
// The second value is the full trajectory where the step size is variable step used by the propagator.
let (future_sc, trajectory) = Propagator::default(dynamics)
.with(sc, almanac.clone())
.until_epoch_with_traj(future_orbit_tb.epoch)?;
println!("=== High fidelity propagation ===");
println!(
"SMA changed by {:.3} km",
orbit.sma_km()? - future_sc.orbit.sma_km()?
);
println!(
"ECC changed by {:.6}",
orbit.ecc()? - future_sc.orbit.ecc()?
);
println!(
"INC changed by {:.3e} deg",
orbit.inc_deg()? - future_sc.orbit.inc_deg()?
);
println!(
"RAAN changed by {:.3} deg",
orbit.raan_deg()? - future_sc.orbit.raan_deg()?
);
println!(
"AOP changed by {:.3} deg",
orbit.aop_deg()? - future_sc.orbit.aop_deg()?
);
println!(
"TA changed by {:.3} deg",
orbit.ta_deg()? - future_sc.orbit.ta_deg()?
);
// We also have access to the full trajectory throughout the propagation.
println!("{trajectory}");
// With the trajectory, let's build a few data products.
// 1. Export the trajectory as a CCSDS OEM version 2.0 file and as a parquet file, which includes the Keplerian orbital elements.
trajectory.to_oem_file(
"./01_cubesat_hf_prop.oem",
ExportCfg::builder().step(Unit::Minute * 2).build(),
)?;
trajectory.to_parquet_with_cfg(
"./01_cubesat_hf_prop.parquet",
ExportCfg::builder().step(Unit::Minute * 2).build(),
almanac.clone(),
)?;
// 2. Compare the difference in the radial-intrack-crosstrack frame between the high fidelity
// and Keplerian propagation. The RIC frame is commonly used to compute the difference in position
// and velocity of different spacecraft.
// 3. Compute the azimuth, elevation, range, and range-rate data of that spacecraft as seen from Boulder, CO, USA.
let boulder_station = GroundStation::from_point(
"Boulder, CO, USA".to_string(),
40.014984, // latitude in degrees
-105.270546, // longitude in degrees
1.6550, // altitude in kilometers
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
);
// We iterate over the trajectory, grabbing a state every two minutes.
let mut offset_s = vec![];
let mut epoch_str = vec![];
let mut ric_x_km = vec![];
let mut ric_y_km = vec![];
let mut ric_z_km = vec![];
let mut ric_vx_km_s = vec![];
let mut ric_vy_km_s = vec![];
let mut ric_vz_km_s = vec![];
let mut azimuth_deg = vec![];
let mut elevation_deg = vec![];
let mut range_km = vec![];
let mut range_rate_km_s = vec![];
for state in trajectory.every(Unit::Minute * 2) {
// Try to compute the Keplerian/two body state just in time.
// This method occasionally fails to converge on an appropriate true anomaly
// from the mean anomaly. If that happens, we just skip this state.
// The high fidelity and Keplerian states diverge continuously, and we're curious
// about the divergence in this quick analysis.
let this_epoch = state.epoch();
match orbit.at_epoch(this_epoch) {
Ok(tb_then) => {
offset_s.push((this_epoch - orbit.epoch).to_seconds());
epoch_str.push(format!("{this_epoch}"));
// Compute the two body state just in time.
let ric = state.orbit.ric_difference(&tb_then)?;
ric_x_km.push(ric.radius_km.x);
ric_y_km.push(ric.radius_km.y);
ric_z_km.push(ric.radius_km.z);
ric_vx_km_s.push(ric.velocity_km_s.x);
ric_vy_km_s.push(ric.velocity_km_s.y);
ric_vz_km_s.push(ric.velocity_km_s.z);
// Compute the AER data for each state.
let aer = almanac.azimuth_elevation_range_sez(
state.orbit,
boulder_station.to_orbit(this_epoch, &almanac)?,
)?;
azimuth_deg.push(aer.azimuth_deg);
elevation_deg.push(aer.elevation_deg);
range_km.push(aer.range_km);
range_rate_km_s.push(aer.range_rate_km_s);
}
Err(e) => warn!("{} {e}", state.epoch()),
};
}
// Build the data frames.
let ric_df = df!(
"Offset (s)" => offset_s.clone(),
"Epoch" => epoch_str.clone(),
"RIC X (km)" => ric_x_km,
"RIC Y (km)" => ric_y_km,
"RIC Z (km)" => ric_z_km,
"RIC VX (km/s)" => ric_vx_km_s,
"RIC VY (km/s)" => ric_vy_km_s,
"RIC VZ (km/s)" => ric_vz_km_s,
)?;
println!("RIC difference at start\n{}", ric_df.head(Some(10)));
println!("RIC difference at end\n{}", ric_df.tail(Some(10)));
let aer_df = df!(
"Offset (s)" => offset_s.clone(),
"Epoch" => epoch_str.clone(),
"azimuth (deg)" => azimuth_deg,
"elevation (deg)" => elevation_deg,
"range (km)" => range_km,
"range rate (km/s)" => range_rate_km_s,
)?;
// Finally, let's see when the spacecraft is visible, assuming 15 degrees minimum elevation.
let mask = aer_df.column("elevation (deg)")?.gt(15.0)?;
let cubesat_visible = aer_df.filter(&mask)?;
println!("{cubesat_visible}");
Ok(())
}
§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.
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.
§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?
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Set up the dynamics like in the orbit raise.
let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
// Define the GEO orbit, and we're just going to maintain it very tightly.
let earth_j2000 = almanac.frame_from_uid(EARTH_J2000)?;
let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
println!("{orbit:x}");
let sc = Spacecraft::builder()
.orbit(orbit)
.dry_mass_kg(1000.0) // 1000 kg of dry mass
.fuel_mass_kg(1000.0) // 1000 kg of fuel, totalling 2.0 tons
.srp(SrpConfig::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
.thruster(Thruster {
// "NEXT-STEP" row in Table 2
isp_s: 4435.0,
thrust_N: 0.472,
})
.mode(GuidanceMode::Thrust) // Start thrusting immediately.
.build();
// Set up the spacecraft dynamics like in the orbit raise example.
let prop_time = 30.0 * Unit::Day;
// Define the guidance law -- we're just using a Ruggiero controller as demonstrated in AAS-2004-5089.
let objectives = &[
Objective::within_tolerance(StateParameter::SMA, 42_164.0, 5.0), // 5 km
Objective::within_tolerance(StateParameter::Eccentricity, 0.001, 5e-5),
Objective::within_tolerance(StateParameter::Inclination, 0.05, 1e-2),
];
let ruggiero_ctrl = Ruggiero::from_max_eclipse(objectives, sc, EclipseState::Penumbra(0.2))?;
println!("{ruggiero_ctrl}");
let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
let mut jgm3_meta = MetaFile {
uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
};
jgm3_meta.process()?;
let harmonics = Harmonics::from_stor(
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
HarmonicsMem::from_cof(&jgm3_meta.uri, 8, 8, true)?,
);
orbital_dyn.accel_models.push(harmonics);
let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
.with_guidance_law(ruggiero_ctrl.clone());
println!("{sc_dynamics}");
// Finally, let's use the Monte Carlo framework built into Nyx to propagate spacecraft.
// Let's start by defining the dispersion.
// 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.
// Note that additional validation on the MVN is in progress -- https://github.com/nyx-space/nyx/issues/339.
let mc_rv = MultivariateNormal::new(
sc,
vec![StateDispersion::zero_mean(StateParameter::SMA, 3.0)],
)?;
let my_mc = MonteCarlo::new(
sc, // Nominal state
mc_rv,
"03_geo_sk".to_string(), // Scenario name
None, // No specific seed specified, so one will be drawn from the computer's entropy.
);
// Build the propagator setup.
let setup = Propagator::rk89(
sc_dynamics.clone(),
PropOpts::builder()
.min_step(10.0_f64.seconds())
.error_ctrl(RSSCartesianStep {})
.build(),
);
let num_runs = 25;
let rslts = my_mc.run_until_epoch(setup, almanac.clone(), sc.epoch() + prop_time, num_runs);
assert_eq!(rslts.runs.len(), num_runs);
// For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
rslts.to_parquet(
"03_geo_sk.parquet",
Some(vec![
&EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
]),
ExportCfg::default(),
almanac,
)?;
Ok(())
}
More examples
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// This will automatically download the DE440s planetary ephemeris,
// the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
// parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
// planetary constants kernels.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
// references to many functions.
let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
// Fetch the EME2000 frame from the Almabac
let eme2k = almanac.frame_from_uid(EARTH_J2000).unwrap();
// Define the orbit epoch
let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
// Build the spacecraft itself.
// Using slide 6 of https://aerospace.org/sites/default/files/2018-11/Davis-Mayberry_HPSEP_11212018.pdf
// for the "next gen" SEP characteristics.
// GTO start
let orbit = Orbit::keplerian(24505.9, 0.725, 7.05, 0.0, 0.0, 0.0, epoch, eme2k);
let sc = Spacecraft::builder()
.orbit(orbit)
.dry_mass_kg(1000.0) // 1000 kg of dry mass
.fuel_mass_kg(1000.0) // 1000 kg of fuel, totalling 2.0 tons
.srp(SrpConfig::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
.thruster(Thruster {
// "NEXT-STEP" row in Table 2
isp_s: 4435.0,
thrust_N: 0.472,
})
.mode(GuidanceMode::Thrust) // Start thrusting immediately.
.build();
let prop_time = 180.0 * Unit::Day;
// Define the guidance law -- we're just using a Ruggiero controller as demonstrated in AAS-2004-5089.
let objectives = &[
Objective::within_tolerance(StateParameter::SMA, 42_165.0, 20.0),
Objective::within_tolerance(StateParameter::Eccentricity, 0.001, 5e-5),
Objective::within_tolerance(StateParameter::Inclination, 0.05, 1e-2),
];
// Ensure that we only thrust if we have more than 20% illumination.
let ruggiero_ctrl =
Ruggiero::from_max_eclipse(objectives, sc, EclipseState::Penumbra(0.2)).unwrap();
println!("{ruggiero_ctrl}");
// Define the high fidelity dynamics
// Set up the spacecraft dynamics.
// Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
// The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
// We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
// We're using the JGM3 model here, which is the default in GMAT.
let mut jgm3_meta = MetaFile {
uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
};
// And let's download it if we don't have it yet.
jgm3_meta.process()?;
// Build the spherical harmonics.
// The harmonics must be computed in the body fixed frame.
// We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
let harmonics = Harmonics::from_stor(
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
HarmonicsMem::from_cof(&jgm3_meta.uri, 8, 8, true).unwrap(),
);
// Include the spherical harmonics into the orbital dynamics.
orbital_dyn.accel_models.push(harmonics);
// We define the solar radiation pressure, using the default solar flux and accounting only
// for the eclipsing caused by the Earth.
let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
// Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
// acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
.with_guidance_law(ruggiero_ctrl.clone());
println!("{:x}", orbit);
// We specify a minimum step in the propagator because the Ruggiero control would otherwise drive this step very low.
let (final_state, traj) = Propagator::rk89(
sc_dynamics.clone(),
PropOpts::builder()
.min_step(10.0_f64.seconds())
.error_ctrl(RSSCartesianStep {})
.build(),
)
.with(sc, almanac.clone())
.for_duration_with_traj(prop_time)?;
let fuel_usage = sc.fuel_mass_kg - final_state.fuel_mass_kg;
println!("{:x}", final_state.orbit);
println!("fuel usage: {:.3} kg", fuel_usage);
// Finally, export the results for analysis, including the penumbra percentage throughout the orbit raise.
traj.to_parquet(
"./03_geo_raise.parquet",
Some(vec![
&EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
]),
ExportCfg::default(),
almanac,
)?;
for status_line in ruggiero_ctrl.status(&final_state) {
println!("{status_line}");
}
ruggiero_ctrl
.achieved(&final_state)
.expect("objective not achieved");
Ok(())
}
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// This will automatically download the DE440s planetary ephemeris,
// the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
// parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
// planetary constants kernels.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
// references to many functions.
let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
// Define the orbit epoch
let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
// Define the orbit.
// First we need to fetch the Earth J2000 from information from the Almanac.
// This allows the frame to include the gravitational parameters and the shape of the Earth,
// defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
// by loading a different set of planetary constants.
let earth_j2000 = almanac.frame_from_uid(EARTH_J2000)?;
// Placing this GEO bird just above Colorado.
// In theory, the eccentricity is zero, but in practice, it's about 1e-5 to 1e-6 at best.
let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
// Print in in Keplerian form.
println!("{orbit:x}");
let state_bf = almanac.transform_to(orbit, IAU_EARTH_FRAME, None)?;
let (orig_lat_deg, orig_long_deg, orig_alt_km) = state_bf.latlongalt()?;
// Nyx is used for high fidelity propagation, not Keplerian propagation as above.
// Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
// models such as solar radiation pressure.
// Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
let sc = Spacecraft::builder()
.orbit(orbit)
.dry_mass_kg(9.60)
.srp(SrpConfig {
area_m2: 10e-4,
cr: 1.1,
})
.build();
println!("{sc:x}");
// Set up the spacecraft dynamics.
// Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
// The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
// We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
// We're using the JGM3 model here, which is the default in GMAT.
let mut jgm3_meta = MetaFile {
uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
};
// And let's download it if we don't have it yet.
jgm3_meta.process()?;
// Build the spherical harmonics.
// The harmonics must be computed in the body fixed frame.
// We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
let harmonics_21x21 = Harmonics::from_stor(
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
);
// Include the spherical harmonics into the orbital dynamics.
orbital_dyn.accel_models.push(harmonics_21x21);
// We define the solar radiation pressure, using the default solar flux and accounting only
// for the eclipsing caused by the Earth and Moon.
let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
// Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
// acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
println!("{dynamics}");
// Finally, let's propagate this orbit to the same epoch as above.
// The first returned value is the spacecraft state at the final epoch.
// The second value is the full trajectory where the step size is variable step used by the propagator.
let (future_sc, trajectory) = Propagator::default(dynamics)
.with(sc, almanac.clone())
.until_epoch_with_traj(epoch + Unit::Century * 0.03)?;
println!("=== High fidelity propagation ===");
println!(
"SMA changed by {:.3} km",
orbit.sma_km()? - future_sc.orbit.sma_km()?
);
println!(
"ECC changed by {:.6}",
orbit.ecc()? - future_sc.orbit.ecc()?
);
println!(
"INC changed by {:.3e} deg",
orbit.inc_deg()? - future_sc.orbit.inc_deg()?
);
println!(
"RAAN changed by {:.3} deg",
orbit.raan_deg()? - future_sc.orbit.raan_deg()?
);
println!(
"AOP changed by {:.3} deg",
orbit.aop_deg()? - future_sc.orbit.aop_deg()?
);
println!(
"TA changed by {:.3} deg",
orbit.ta_deg()? - future_sc.orbit.ta_deg()?
);
// We also have access to the full trajectory throughout the propagation.
println!("{trajectory}");
println!("Spacecraft params after 3 years without active control:\n{future_sc:x}");
// With the trajectory, let's build a few data products.
// 1. Export the trajectory as a parquet file, which includes the Keplerian orbital elements.
let analysis_step = Unit::Minute * 5;
trajectory.to_parquet(
"./03_geo_hf_prop.parquet",
Some(vec![
&EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
]),
ExportCfg::builder().step(analysis_step).build(),
almanac.clone(),
)?;
// 2. Compute the latitude, longitude, and altitude throughout the trajectory by rotating the spacecraft position into the Earth body fixed frame.
// We iterate over the trajectory, grabbing a state every two minutes.
let mut offset_s = vec![];
let mut epoch_str = vec![];
let mut longitude_deg = vec![];
let mut latitude_deg = vec![];
let mut altitude_km = vec![];
for state in trajectory.every(analysis_step) {
// Convert the GEO bird state into the body fixed frame, and keep track of its latitude, longitude, and altitude.
// These define the GEO stationkeeping box.
let this_epoch = state.epoch();
offset_s.push((this_epoch - orbit.epoch).to_seconds());
epoch_str.push(this_epoch.to_isoformat());
let state_bf = almanac.transform_to(state.orbit, IAU_EARTH_FRAME, None)?;
let (lat_deg, long_deg, alt_km) = state_bf.latlongalt()?;
longitude_deg.push(long_deg);
latitude_deg.push(lat_deg);
altitude_km.push(alt_km);
}
println!(
"Longitude changed by {:.3} deg -- Box is 0.1 deg E-W",
orig_long_deg - longitude_deg.last().unwrap()
);
println!(
"Latitude changed by {:.3} deg -- Box is 0.05 deg N-S",
orig_lat_deg - latitude_deg.last().unwrap()
);
println!(
"Altitude changed by {:.3} km -- Box is 30 km",
orig_alt_km - altitude_km.last().unwrap()
);
// Build the station keeping data frame.
let mut sk_df = df!(
"Offset (s)" => offset_s.clone(),
"Epoch (UTC)" => epoch_str.clone(),
"Longitude E-W (deg)" => longitude_deg,
"Latitude N-S (deg)" => latitude_deg,
"Altitude (km)" => altitude_km,
)?;
// Create a file to write the Parquet to
let file = File::create("./03_geo_lla.parquet").expect("Could not create file");
// Create a ParquetWriter and write the DataFrame to the file
ParquetWriter::new(file).finish(&mut sk_df)?;
Ok(())
}
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// ====================== //
// === ALMANAC SET UP === //
// ====================== //
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's MetaAlmanac.
let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
.iter()
.collect();
let meta = data_folder.join("lro-dynamics.dhall");
// Load this ephem in the general Almanac we're using for this analysis.
let mut almanac = MetaAlmanac::new(meta.to_string_lossy().to_string())
.map_err(Box::new)?
.process()
.map_err(Box::new)?;
let mut moon_pc = almanac.planetary_data.get_by_id(MOON)?;
moon_pc.mu_km3_s2 = 4902.74987;
almanac.planetary_data.set_by_id(MOON, moon_pc)?;
let mut earth_pc = almanac.planetary_data.get_by_id(EARTH)?;
earth_pc.mu_km3_s2 = 398600.436;
almanac.planetary_data.set_by_id(EARTH, earth_pc)?;
// Save this new kernel for reuse.
// In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
almanac
.planetary_data
.save_as(&data_folder.join("lro-specific.pca"), true)?;
// Lock the almanac (an Arc is a read only structure).
let almanac = Arc::new(almanac);
// Orbit determination requires a Trajectory structure, which can be saved as parquet file.
// In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
// To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
// Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
let lro_frame = Frame::from_ephem_j2000(-85);
// To build the trajectory we need to provide a spacecraft template.
let sc_template = Spacecraft::builder()
.dry_mass_kg(1018.0) // Launch masses
.fuel_mass_kg(900.0)
.srp(SrpConfig {
// SRP configuration is arbitrary, but we will be estimating it anyway.
area_m2: 3.9 * 2.7,
cr: 0.96,
})
.orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
.build();
// Now we can build the trajectory from the BSP file.
// We'll arbitrarily set the tracking arc to 48 hours with a one minute time step.
let traj_as_flown = Traj::from_bsp(
lro_frame,
MOON_J2000,
almanac.clone(),
sc_template,
5.seconds(),
Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
Aberration::LT,
Some("LRO".to_string()),
)?;
println!("{traj_as_flown}");
// ====================== //
// === MODEL MATCHING === //
// ====================== //
// Set up the spacecraft dynamics.
// Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
// The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
// We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
// We're using the GRAIL JGGRX model.
let mut jggrx_meta = MetaFile {
uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
};
// And let's download it if we don't have it yet.
jggrx_meta.process()?;
// Build the spherical harmonics.
// The harmonics must be computed in the body fixed frame.
// We're using the long term prediction of the Moon principal axes frame.
let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
// let moon_pa_frame = IAU_MOON_FRAME;
let sph_harmonics = Harmonics::from_stor(
almanac.frame_from_uid(moon_pa_frame)?,
HarmonicsMem::from_shadr(&jggrx_meta.uri, 80, 80, true)?,
);
// Include the spherical harmonics into the orbital dynamics.
orbital_dyn.accel_models.push(sph_harmonics);
// We define the solar radiation pressure, using the default solar flux and accounting only
// for the eclipsing caused by the Earth and Moon.
// Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
// Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
// acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
println!("{dynamics}");
// Now we can build the propagator.
let setup = Propagator::default_dp78(dynamics.clone());
// For reference, let's build the trajectory with Nyx's models from that LRO state.
let (sim_final, traj_as_sim) = setup
.with(*traj_as_flown.first(), almanac.clone())
.until_epoch_with_traj(traj_as_flown.last().epoch())?;
println!("SIM INIT: {:x}", traj_as_flown.first());
println!("SIM FINAL: {sim_final:x}");
// Compute RIC difference between SIM and LRO ephem
let sim_lro_delta = sim_final
.orbit
.ric_difference(&traj_as_flown.last().orbit)?;
println!("{traj_as_sim}");
println!(
"SIM v LRO - RIC Position (m): {:.3}",
sim_lro_delta.radius_km * 1e3
);
println!(
"SIM v LRO - RIC Velocity (m/s): {:.3}",
sim_lro_delta.velocity_km_s * 1e3
);
traj_as_sim.ric_diff_to_parquet(
&traj_as_flown,
"./04_lro_sim_truth_error.parquet",
ExportCfg::default(),
)?;
// ==================== //
// === OD SIMULATOR === //
// ==================== //
// 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
// and the truth LRO state.
// Therefore, we will actually run an estimation from a dispersed LRO state.
// The sc_seed is the true LRO state from the BSP.
let sc_seed = *traj_as_flown.first();
// Load the Deep Space Network ground stations.
// Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
let ground_station_file: PathBuf = [
env!("CARGO_MANIFEST_DIR"),
"examples",
"04_lro_od",
"dsn-network.yaml",
]
.iter()
.collect();
let devices = GroundStation::load_many(ground_station_file)?;
// Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
// Nyx can build a tracking schedule for you based on the first station with access.
let trkconfg_yaml: PathBuf = [
env!("CARGO_MANIFEST_DIR"),
"examples",
"04_lro_od",
"tracking-cfg.yaml",
]
.iter()
.collect();
let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
// Build the tracking arc simulation to generate a "standard measurement".
let mut trk = TrackingArcSim::<Spacecraft, RangeDoppler, _>::new(
devices,
traj_as_flown.clone(),
configs,
)?;
trk.build_schedule(almanac.clone())?;
let arc = trk.generate_measurements(almanac.clone())?;
// Save the simulated tracking data
arc.to_parquet_simple("./04_lro_simulated_tracking.parquet")?;
// We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
println!("{arc}");
// Now that we have simulated measurements, we'll run the orbit determination.
// ===================== //
// === OD ESTIMATION === //
// ===================== //
let sc = SpacecraftUncertainty::builder()
.nominal(sc_seed)
.frame(LocalFrame::RIC)
.x_km(0.5)
.y_km(0.5)
.z_km(0.5)
.vx_km_s(5e-3)
.vy_km_s(5e-3)
.vz_km_s(5e-3)
.build();
// Build the filter initial estimate, which we will reuse in the filter.
let initial_estimate = sc.to_estimate()?;
println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
let kf = KF::new(
// Increase the initial covariance to account for larger deviation.
initial_estimate,
// Until https://github.com/nyx-space/nyx/issues/351, we need to specify the SNC in the acceleration of the Moon J2000 frame.
SNC3::from_diagonal(10 * Unit::Minute, &[1e-11, 1e-11, 1e-11]),
);
// We'll set up the OD process to reject measurements whose residuals are mover than 4 sigmas away from what we expect.
let mut odp = ODProcess::ckf(
setup.with(initial_estimate.state().with_stm(), almanac.clone()),
kf,
Some(ResidRejectCrit::default()),
almanac.clone(),
);
odp.process_arc::<GroundStation>(&arc)?;
let ric_err = traj_as_flown
.at(odp.estimates.last().unwrap().epoch())?
.orbit
.ric_difference(&odp.estimates.last().unwrap().orbital_state())?;
println!("== RIC at end ==");
println!("RIC Position (m): {}", ric_err.radius_km * 1e3);
println!("RIC Velocity (m/s): {}", ric_err.velocity_km_s * 1e3);
odp.to_parquet("./04_lro_od_results.parquet", ExportCfg::default())?;
// In our case, we have the truth trajectory from NASA.
// So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
// Export the OD trajectory first.
let od_trajectory = odp.to_traj()?;
// Build the RIC difference.
od_trajectory.ric_diff_to_parquet(
&traj_as_flown,
"./04_lro_od_truth_error.parquet",
ExportCfg::default(),
)?;
Ok(())
}
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// This will automatically download the DE440s planetary ephemeris,
// the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
// parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
// planetary constants kernels.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
// references to many functions.
let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
// Define the orbit epoch
let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
// Define the orbit.
// First we need to fetch the Earth J2000 from information from the Almanac.
// This allows the frame to include the gravitational parameters and the shape of the Earth,
// defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
// by loading a different set of planetary constants.
let earth_j2000 = almanac.frame_from_uid(EARTH_J2000)?;
let orbit =
Orbit::try_keplerian_altitude(300.0, 0.015, 68.5, 65.2, 75.0, 0.0, epoch, earth_j2000)?;
// Print in in Keplerian form.
println!("{orbit:x}");
// There are two ways to propagate an orbit. We can make a quick approximation assuming only two-body
// motion. This is a useful first order approximation but it isn't used in real-world applications.
// This approach is a feature of ANISE.
let future_orbit_tb = orbit.at_epoch(epoch + Unit::Day * 3)?;
println!("{future_orbit_tb:x}");
// Two body propagation relies solely on Kepler's laws, so only the true anomaly will change.
println!(
"SMA changed by {:.3e} km",
orbit.sma_km()? - future_orbit_tb.sma_km()?
);
println!(
"ECC changed by {:.3e}",
orbit.ecc()? - future_orbit_tb.ecc()?
);
println!(
"INC changed by {:.3e} deg",
orbit.inc_deg()? - future_orbit_tb.inc_deg()?
);
println!(
"RAAN changed by {:.3e} deg",
orbit.raan_deg()? - future_orbit_tb.raan_deg()?
);
println!(
"AOP changed by {:.3e} deg",
orbit.aop_deg()? - future_orbit_tb.aop_deg()?
);
println!(
"TA changed by {:.3} deg",
orbit.ta_deg()? - future_orbit_tb.ta_deg()?
);
// Nyx is used for high fidelity propagation, not Keplerian propagation as above.
// Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
// models such as solar radiation pressure.
// Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
let sc = Spacecraft::builder()
.orbit(orbit)
.dry_mass_kg(9.60)
.srp(SrpConfig {
area_m2: 10e-4,
cr: 1.1,
})
.build();
println!("{sc:x}");
// Set up the spacecraft dynamics.
// Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
// The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
// We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
// We're using the JGM3 model here, which is the default in GMAT.
let mut jgm3_meta = MetaFile {
uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
};
// And let's download it if we don't have it yet.
jgm3_meta.process()?;
// Build the spherical harmonics.
// The harmonics must be computed in the body fixed frame.
// We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
let harmonics_21x21 = Harmonics::from_stor(
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
);
// Include the spherical harmonics into the orbital dynamics.
orbital_dyn.accel_models.push(harmonics_21x21);
// We define the solar radiation pressure, using the default solar flux and accounting only
// for the eclipsing caused by the Earth.
let srp_dyn = SolarPressure::default(EARTH_J2000, almanac.clone())?;
// Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
// acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
println!("{dynamics}");
// Finally, let's propagate this orbit to the same epoch as above.
// The first returned value is the spacecraft state at the final epoch.
// The second value is the full trajectory where the step size is variable step used by the propagator.
let (future_sc, trajectory) = Propagator::default(dynamics)
.with(sc, almanac.clone())
.until_epoch_with_traj(future_orbit_tb.epoch)?;
println!("=== High fidelity propagation ===");
println!(
"SMA changed by {:.3} km",
orbit.sma_km()? - future_sc.orbit.sma_km()?
);
println!(
"ECC changed by {:.6}",
orbit.ecc()? - future_sc.orbit.ecc()?
);
println!(
"INC changed by {:.3e} deg",
orbit.inc_deg()? - future_sc.orbit.inc_deg()?
);
println!(
"RAAN changed by {:.3} deg",
orbit.raan_deg()? - future_sc.orbit.raan_deg()?
);
println!(
"AOP changed by {:.3} deg",
orbit.aop_deg()? - future_sc.orbit.aop_deg()?
);
println!(
"TA changed by {:.3} deg",
orbit.ta_deg()? - future_sc.orbit.ta_deg()?
);
// We also have access to the full trajectory throughout the propagation.
println!("{trajectory}");
// With the trajectory, let's build a few data products.
// 1. Export the trajectory as a CCSDS OEM version 2.0 file and as a parquet file, which includes the Keplerian orbital elements.
trajectory.to_oem_file(
"./01_cubesat_hf_prop.oem",
ExportCfg::builder().step(Unit::Minute * 2).build(),
)?;
trajectory.to_parquet_with_cfg(
"./01_cubesat_hf_prop.parquet",
ExportCfg::builder().step(Unit::Minute * 2).build(),
almanac.clone(),
)?;
// 2. Compare the difference in the radial-intrack-crosstrack frame between the high fidelity
// and Keplerian propagation. The RIC frame is commonly used to compute the difference in position
// and velocity of different spacecraft.
// 3. Compute the azimuth, elevation, range, and range-rate data of that spacecraft as seen from Boulder, CO, USA.
let boulder_station = GroundStation::from_point(
"Boulder, CO, USA".to_string(),
40.014984, // latitude in degrees
-105.270546, // longitude in degrees
1.6550, // altitude in kilometers
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
);
// We iterate over the trajectory, grabbing a state every two minutes.
let mut offset_s = vec![];
let mut epoch_str = vec![];
let mut ric_x_km = vec![];
let mut ric_y_km = vec![];
let mut ric_z_km = vec![];
let mut ric_vx_km_s = vec![];
let mut ric_vy_km_s = vec![];
let mut ric_vz_km_s = vec![];
let mut azimuth_deg = vec![];
let mut elevation_deg = vec![];
let mut range_km = vec![];
let mut range_rate_km_s = vec![];
for state in trajectory.every(Unit::Minute * 2) {
// Try to compute the Keplerian/two body state just in time.
// This method occasionally fails to converge on an appropriate true anomaly
// from the mean anomaly. If that happens, we just skip this state.
// The high fidelity and Keplerian states diverge continuously, and we're curious
// about the divergence in this quick analysis.
let this_epoch = state.epoch();
match orbit.at_epoch(this_epoch) {
Ok(tb_then) => {
offset_s.push((this_epoch - orbit.epoch).to_seconds());
epoch_str.push(format!("{this_epoch}"));
// Compute the two body state just in time.
let ric = state.orbit.ric_difference(&tb_then)?;
ric_x_km.push(ric.radius_km.x);
ric_y_km.push(ric.radius_km.y);
ric_z_km.push(ric.radius_km.z);
ric_vx_km_s.push(ric.velocity_km_s.x);
ric_vy_km_s.push(ric.velocity_km_s.y);
ric_vz_km_s.push(ric.velocity_km_s.z);
// Compute the AER data for each state.
let aer = almanac.azimuth_elevation_range_sez(
state.orbit,
boulder_station.to_orbit(this_epoch, &almanac)?,
)?;
azimuth_deg.push(aer.azimuth_deg);
elevation_deg.push(aer.elevation_deg);
range_km.push(aer.range_km);
range_rate_km_s.push(aer.range_rate_km_s);
}
Err(e) => warn!("{} {e}", state.epoch()),
};
}
// Build the data frames.
let ric_df = df!(
"Offset (s)" => offset_s.clone(),
"Epoch" => epoch_str.clone(),
"RIC X (km)" => ric_x_km,
"RIC Y (km)" => ric_y_km,
"RIC Z (km)" => ric_z_km,
"RIC VX (km/s)" => ric_vx_km_s,
"RIC VY (km/s)" => ric_vy_km_s,
"RIC VZ (km/s)" => ric_vz_km_s,
)?;
println!("RIC difference at start\n{}", ric_df.head(Some(10)));
println!("RIC difference at end\n{}", ric_df.tail(Some(10)));
let aer_df = df!(
"Offset (s)" => offset_s.clone(),
"Epoch" => epoch_str.clone(),
"azimuth (deg)" => azimuth_deg,
"elevation (deg)" => elevation_deg,
"range (km)" => range_km,
"range rate (km/s)" => range_rate_km_s,
)?;
// Finally, let's see when the spacecraft is visible, assuming 15 degrees minimum elevation.
let mask = aer_df.column("elevation (deg)")?.gt(15.0)?;
let cubesat_visible = aer_df.filter(&mask)?;
println!("{cubesat_visible}");
Ok(())
}
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.
§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.
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.
Examples found in repository?
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Download the regularly update of the James Webb Space Telescope reconstucted (or definitive) ephemeris.
// Refer to https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/aareadme.txt for details.
let mut latest_jwst_ephem = MetaFile {
uri: "https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/jwst_rec.bsp".to_string(),
crc32: None,
};
latest_jwst_ephem.process()?;
// Load this ephem in the general Almanac we're using for this analysis.
let almanac = Arc::new(
MetaAlmanac::latest()
.map_err(Box::new)?
.load_from_metafile(latest_jwst_ephem)?,
);
// By loading this ephemeris file in the ANISE GUI or ANISE CLI, we can find the NAIF ID of the JWST
// in the BSP. We need this ID in order to query the ephemeris.
const JWST_NAIF_ID: i32 = -170;
// Let's build a frame in the J2000 orientation centered on the JWST.
const JWST_J2000: Frame = Frame::from_ephem_j2000(JWST_NAIF_ID);
// Since the ephemeris file is updated regularly, we'll just grab the latest state in the ephem.
let (earliest_epoch, latest_epoch) = almanac.spk_domain(JWST_NAIF_ID)?;
println!("JWST defined from {earliest_epoch} to {latest_epoch}");
// Fetch the state, printing it in the Earth J2000 frame.
let jwst_orbit = almanac.transform(JWST_J2000, EARTH_J2000, latest_epoch, None)?;
println!("{jwst_orbit:x}");
// Build the spacecraft
// 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
// 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
let jwst = Spacecraft::builder()
.orbit(jwst_orbit)
.srp(SrpConfig {
area_m2: 21.197 * 14.162,
cr: 1.56,
})
.dry_mass_kg(6200.0)
.build();
// Build up the spacecraft uncertainty builder.
// We can use the spacecraft uncertainty structure to build this up.
// We start by specifying the nominal state (as defined above), then the uncertainty in position and velocity
// in the RIC frame. We could also specify the Cr, Cd, and mass uncertainties, but these aren't accounted for until
// Nyx can also estimate the deviation of the spacecraft parameters.
let jwst_uncertainty = SpacecraftUncertainty::builder()
.nominal(jwst)
.frame(LocalFrame::RIC)
.x_km(0.5)
.y_km(0.3)
.z_km(1.5)
.vx_km_s(1e-4)
.vy_km_s(0.6e-3)
.vz_km_s(3e-3)
.build();
println!("{jwst_uncertainty}");
// Build the Kalman filter estimate.
// Note that we could have used the KfEstimate structure directly (as seen throughout the OD integration tests)
// but this approach requires quite a bit more boilerplate code.
let jwst_estimate = jwst_uncertainty.to_estimate()?;
// Set up the spacecraft dynamics.
// We'll use the point masses of the Earth, Sun, Jupiter (barycenter, because it's in the DE440), and the Moon.
// We'll also enable solar radiation pressure since the James Webb has a huge and highly reflective sun shield.
let orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN, JUPITER_BARYCENTER]);
let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
// Finalize setting up the dynamics.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
// Build the propagator set up to use for the whole analysis.
let setup = Propagator::default(dynamics);
// All of the analysis will use this duration.
let prediction_duration = 6.5 * Unit::Day;
// === Covariance mapping ===
// For the covariance mapping / prediction, we'll use the common orbit determination approach.
// This is done by setting up a spacecraft OD process, and predicting for the analysis duration.
let ckf = KF::no_snc(jwst_estimate);
// Build the propagation instance for the OD process.
let prop = setup.with(jwst.with_stm(), almanac.clone());
let mut odp = SpacecraftODProcess::ckf(prop, ckf, None, almanac.clone());
// Define the prediction step, i.e. how often we want to know the covariance.
let step = 1_i64.minutes();
// Finally, predict, and export the trajectory with covariance to a parquet file.
odp.predict_for(step, prediction_duration)?;
odp.to_parquet("./02_jwst_covar_map.parquet", ExportCfg::default())?;
// === Monte Carlo framework ===
// Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
let my_mc = MonteCarlo::new(
jwst, // Nominal state
jwst_estimate.to_random_variable()?,
"02_jwst".to_string(), // Scenario name
None, // No specific seed specified, so one will be drawn from the computer's entropy.
);
let num_runs = 5_000;
let rslts = my_mc.run_until_epoch(
setup,
almanac.clone(),
jwst.epoch() + prediction_duration,
num_runs,
);
assert_eq!(rslts.runs.len(), num_runs);
// Finally, export these results, computing the eclipse percentage for all of these results.
// For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
let eclipse_loc = EclipseLocator::cislunar(almanac.clone());
let umbra_event = eclipse_loc.to_umbra_event();
let penumbra_event = eclipse_loc.to_penumbra_event();
rslts.to_parquet(
"02_jwst_monte_carlo.parquet",
Some(vec![&umbra_event, &penumbra_event]),
ExportCfg::default(),
almanac,
)?;
Ok(())
}
§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)
Examples found in repository?
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Download the regularly update of the James Webb Space Telescope reconstucted (or definitive) ephemeris.
// Refer to https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/aareadme.txt for details.
let mut latest_jwst_ephem = MetaFile {
uri: "https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/jwst_rec.bsp".to_string(),
crc32: None,
};
latest_jwst_ephem.process()?;
// Load this ephem in the general Almanac we're using for this analysis.
let almanac = Arc::new(
MetaAlmanac::latest()
.map_err(Box::new)?
.load_from_metafile(latest_jwst_ephem)?,
);
// By loading this ephemeris file in the ANISE GUI or ANISE CLI, we can find the NAIF ID of the JWST
// in the BSP. We need this ID in order to query the ephemeris.
const JWST_NAIF_ID: i32 = -170;
// Let's build a frame in the J2000 orientation centered on the JWST.
const JWST_J2000: Frame = Frame::from_ephem_j2000(JWST_NAIF_ID);
// Since the ephemeris file is updated regularly, we'll just grab the latest state in the ephem.
let (earliest_epoch, latest_epoch) = almanac.spk_domain(JWST_NAIF_ID)?;
println!("JWST defined from {earliest_epoch} to {latest_epoch}");
// Fetch the state, printing it in the Earth J2000 frame.
let jwst_orbit = almanac.transform(JWST_J2000, EARTH_J2000, latest_epoch, None)?;
println!("{jwst_orbit:x}");
// Build the spacecraft
// 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
// 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
let jwst = Spacecraft::builder()
.orbit(jwst_orbit)
.srp(SrpConfig {
area_m2: 21.197 * 14.162,
cr: 1.56,
})
.dry_mass_kg(6200.0)
.build();
// Build up the spacecraft uncertainty builder.
// We can use the spacecraft uncertainty structure to build this up.
// We start by specifying the nominal state (as defined above), then the uncertainty in position and velocity
// in the RIC frame. We could also specify the Cr, Cd, and mass uncertainties, but these aren't accounted for until
// Nyx can also estimate the deviation of the spacecraft parameters.
let jwst_uncertainty = SpacecraftUncertainty::builder()
.nominal(jwst)
.frame(LocalFrame::RIC)
.x_km(0.5)
.y_km(0.3)
.z_km(1.5)
.vx_km_s(1e-4)
.vy_km_s(0.6e-3)
.vz_km_s(3e-3)
.build();
println!("{jwst_uncertainty}");
// Build the Kalman filter estimate.
// Note that we could have used the KfEstimate structure directly (as seen throughout the OD integration tests)
// but this approach requires quite a bit more boilerplate code.
let jwst_estimate = jwst_uncertainty.to_estimate()?;
// Set up the spacecraft dynamics.
// We'll use the point masses of the Earth, Sun, Jupiter (barycenter, because it's in the DE440), and the Moon.
// We'll also enable solar radiation pressure since the James Webb has a huge and highly reflective sun shield.
let orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN, JUPITER_BARYCENTER]);
let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
// Finalize setting up the dynamics.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
// Build the propagator set up to use for the whole analysis.
let setup = Propagator::default(dynamics);
// All of the analysis will use this duration.
let prediction_duration = 6.5 * Unit::Day;
// === Covariance mapping ===
// For the covariance mapping / prediction, we'll use the common orbit determination approach.
// This is done by setting up a spacecraft OD process, and predicting for the analysis duration.
let ckf = KF::no_snc(jwst_estimate);
// Build the propagation instance for the OD process.
let prop = setup.with(jwst.with_stm(), almanac.clone());
let mut odp = SpacecraftODProcess::ckf(prop, ckf, None, almanac.clone());
// Define the prediction step, i.e. how often we want to know the covariance.
let step = 1_i64.minutes();
// Finally, predict, and export the trajectory with covariance to a parquet file.
odp.predict_for(step, prediction_duration)?;
odp.to_parquet("./02_jwst_covar_map.parquet", ExportCfg::default())?;
// === Monte Carlo framework ===
// Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
let my_mc = MonteCarlo::new(
jwst, // Nominal state
jwst_estimate.to_random_variable()?,
"02_jwst".to_string(), // Scenario name
None, // No specific seed specified, so one will be drawn from the computer's entropy.
);
let num_runs = 5_000;
let rslts = my_mc.run_until_epoch(
setup,
almanac.clone(),
jwst.epoch() + prediction_duration,
num_runs,
);
assert_eq!(rslts.runs.len(), num_runs);
// Finally, export these results, computing the eclipse percentage for all of these results.
// For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
let eclipse_loc = EclipseLocator::cislunar(almanac.clone());
let umbra_event = eclipse_loc.to_umbra_event();
let penumbra_event = eclipse_loc.to_penumbra_event();
rslts.to_parquet(
"02_jwst_monte_carlo.parquet",
Some(vec![&umbra_event, &penumbra_event]),
ExportCfg::default(),
almanac,
)?;
Ok(())
}
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.
Examples found in repository?
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// This will automatically download the DE440s planetary ephemeris,
// the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
// parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
// planetary constants kernels.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
// references to many functions.
let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
// Define the orbit epoch
let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
// Define the orbit.
// First we need to fetch the Earth J2000 from information from the Almanac.
// This allows the frame to include the gravitational parameters and the shape of the Earth,
// defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
// by loading a different set of planetary constants.
let earth_j2000 = almanac.frame_from_uid(EARTH_J2000)?;
// Placing this GEO bird just above Colorado.
// In theory, the eccentricity is zero, but in practice, it's about 1e-5 to 1e-6 at best.
let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
// Print in in Keplerian form.
println!("{orbit:x}");
let state_bf = almanac.transform_to(orbit, IAU_EARTH_FRAME, None)?;
let (orig_lat_deg, orig_long_deg, orig_alt_km) = state_bf.latlongalt()?;
// Nyx is used for high fidelity propagation, not Keplerian propagation as above.
// Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
// models such as solar radiation pressure.
// Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
let sc = Spacecraft::builder()
.orbit(orbit)
.dry_mass_kg(9.60)
.srp(SrpConfig {
area_m2: 10e-4,
cr: 1.1,
})
.build();
println!("{sc:x}");
// Set up the spacecraft dynamics.
// Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
// The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
// We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
// We're using the JGM3 model here, which is the default in GMAT.
let mut jgm3_meta = MetaFile {
uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
};
// And let's download it if we don't have it yet.
jgm3_meta.process()?;
// Build the spherical harmonics.
// The harmonics must be computed in the body fixed frame.
// We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
let harmonics_21x21 = Harmonics::from_stor(
almanac.frame_from_uid(IAU_EARTH_FRAME)?,
HarmonicsMem::from_cof(&jgm3_meta.uri, 21, 21, true).unwrap(),
);
// Include the spherical harmonics into the orbital dynamics.
orbital_dyn.accel_models.push(harmonics_21x21);
// We define the solar radiation pressure, using the default solar flux and accounting only
// for the eclipsing caused by the Earth and Moon.
let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
// Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
// acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
println!("{dynamics}");
// Finally, let's propagate this orbit to the same epoch as above.
// The first returned value is the spacecraft state at the final epoch.
// The second value is the full trajectory where the step size is variable step used by the propagator.
let (future_sc, trajectory) = Propagator::default(dynamics)
.with(sc, almanac.clone())
.until_epoch_with_traj(epoch + Unit::Century * 0.03)?;
println!("=== High fidelity propagation ===");
println!(
"SMA changed by {:.3} km",
orbit.sma_km()? - future_sc.orbit.sma_km()?
);
println!(
"ECC changed by {:.6}",
orbit.ecc()? - future_sc.orbit.ecc()?
);
println!(
"INC changed by {:.3e} deg",
orbit.inc_deg()? - future_sc.orbit.inc_deg()?
);
println!(
"RAAN changed by {:.3} deg",
orbit.raan_deg()? - future_sc.orbit.raan_deg()?
);
println!(
"AOP changed by {:.3} deg",
orbit.aop_deg()? - future_sc.orbit.aop_deg()?
);
println!(
"TA changed by {:.3} deg",
orbit.ta_deg()? - future_sc.orbit.ta_deg()?
);
// We also have access to the full trajectory throughout the propagation.
println!("{trajectory}");
println!("Spacecraft params after 3 years without active control:\n{future_sc:x}");
// With the trajectory, let's build a few data products.
// 1. Export the trajectory as a parquet file, which includes the Keplerian orbital elements.
let analysis_step = Unit::Minute * 5;
trajectory.to_parquet(
"./03_geo_hf_prop.parquet",
Some(vec![
&EclipseLocator::cislunar(almanac.clone()).to_penumbra_event()
]),
ExportCfg::builder().step(analysis_step).build(),
almanac.clone(),
)?;
// 2. Compute the latitude, longitude, and altitude throughout the trajectory by rotating the spacecraft position into the Earth body fixed frame.
// We iterate over the trajectory, grabbing a state every two minutes.
let mut offset_s = vec![];
let mut epoch_str = vec![];
let mut longitude_deg = vec![];
let mut latitude_deg = vec![];
let mut altitude_km = vec![];
for state in trajectory.every(analysis_step) {
// Convert the GEO bird state into the body fixed frame, and keep track of its latitude, longitude, and altitude.
// These define the GEO stationkeeping box.
let this_epoch = state.epoch();
offset_s.push((this_epoch - orbit.epoch).to_seconds());
epoch_str.push(this_epoch.to_isoformat());
let state_bf = almanac.transform_to(state.orbit, IAU_EARTH_FRAME, None)?;
let (lat_deg, long_deg, alt_km) = state_bf.latlongalt()?;
longitude_deg.push(long_deg);
latitude_deg.push(lat_deg);
altitude_km.push(alt_km);
}
println!(
"Longitude changed by {:.3} deg -- Box is 0.1 deg E-W",
orig_long_deg - longitude_deg.last().unwrap()
);
println!(
"Latitude changed by {:.3} deg -- Box is 0.05 deg N-S",
orig_lat_deg - latitude_deg.last().unwrap()
);
println!(
"Altitude changed by {:.3} km -- Box is 30 km",
orig_alt_km - altitude_km.last().unwrap()
);
// Build the station keeping data frame.
let mut sk_df = df!(
"Offset (s)" => offset_s.clone(),
"Epoch (UTC)" => epoch_str.clone(),
"Longitude E-W (deg)" => longitude_deg,
"Latitude N-S (deg)" => latitude_deg,
"Altitude (km)" => altitude_km,
)?;
// Create a file to write the Parquet to
let file = File::create("./03_geo_lla.parquet").expect("Could not create file");
// Create a ParquetWriter and write the DataFrame to the file
ParquetWriter::new(file).finish(&mut sk_df)?;
Ok(())
}
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)
§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,
) -> Result<Almanac, AlmanacError>
pub fn load_from_metafile( &self, metafile: MetaFile, ) -> Result<Almanac, AlmanacError>
Load from the provided MetaFile, downloading it if necessary.
Examples found in repository?
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fn main() -> Result<(), Box<dyn Error>> {
pel::init();
// Dynamics models require planetary constants and ephemerides to be defined.
// Let's start by grabbing those by using ANISE's latest MetaAlmanac.
// For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
// Download the regularly update of the James Webb Space Telescope reconstucted (or definitive) ephemeris.
// Refer to https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/aareadme.txt for details.
let mut latest_jwst_ephem = MetaFile {
uri: "https://naif.jpl.nasa.gov/pub/naif/JWST/kernels/spk/jwst_rec.bsp".to_string(),
crc32: None,
};
latest_jwst_ephem.process()?;
// Load this ephem in the general Almanac we're using for this analysis.
let almanac = Arc::new(
MetaAlmanac::latest()
.map_err(Box::new)?
.load_from_metafile(latest_jwst_ephem)?,
);
// By loading this ephemeris file in the ANISE GUI or ANISE CLI, we can find the NAIF ID of the JWST
// in the BSP. We need this ID in order to query the ephemeris.
const JWST_NAIF_ID: i32 = -170;
// Let's build a frame in the J2000 orientation centered on the JWST.
const JWST_J2000: Frame = Frame::from_ephem_j2000(JWST_NAIF_ID);
// Since the ephemeris file is updated regularly, we'll just grab the latest state in the ephem.
let (earliest_epoch, latest_epoch) = almanac.spk_domain(JWST_NAIF_ID)?;
println!("JWST defined from {earliest_epoch} to {latest_epoch}");
// Fetch the state, printing it in the Earth J2000 frame.
let jwst_orbit = almanac.transform(JWST_J2000, EARTH_J2000, latest_epoch, None)?;
println!("{jwst_orbit:x}");
// Build the spacecraft
// 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
// 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
let jwst = Spacecraft::builder()
.orbit(jwst_orbit)
.srp(SrpConfig {
area_m2: 21.197 * 14.162,
cr: 1.56,
})
.dry_mass_kg(6200.0)
.build();
// Build up the spacecraft uncertainty builder.
// We can use the spacecraft uncertainty structure to build this up.
// We start by specifying the nominal state (as defined above), then the uncertainty in position and velocity
// in the RIC frame. We could also specify the Cr, Cd, and mass uncertainties, but these aren't accounted for until
// Nyx can also estimate the deviation of the spacecraft parameters.
let jwst_uncertainty = SpacecraftUncertainty::builder()
.nominal(jwst)
.frame(LocalFrame::RIC)
.x_km(0.5)
.y_km(0.3)
.z_km(1.5)
.vx_km_s(1e-4)
.vy_km_s(0.6e-3)
.vz_km_s(3e-3)
.build();
println!("{jwst_uncertainty}");
// Build the Kalman filter estimate.
// Note that we could have used the KfEstimate structure directly (as seen throughout the OD integration tests)
// but this approach requires quite a bit more boilerplate code.
let jwst_estimate = jwst_uncertainty.to_estimate()?;
// Set up the spacecraft dynamics.
// We'll use the point masses of the Earth, Sun, Jupiter (barycenter, because it's in the DE440), and the Moon.
// We'll also enable solar radiation pressure since the James Webb has a huge and highly reflective sun shield.
let orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN, JUPITER_BARYCENTER]);
let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], almanac.clone())?;
// Finalize setting up the dynamics.
let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
// Build the propagator set up to use for the whole analysis.
let setup = Propagator::default(dynamics);
// All of the analysis will use this duration.
let prediction_duration = 6.5 * Unit::Day;
// === Covariance mapping ===
// For the covariance mapping / prediction, we'll use the common orbit determination approach.
// This is done by setting up a spacecraft OD process, and predicting for the analysis duration.
let ckf = KF::no_snc(jwst_estimate);
// Build the propagation instance for the OD process.
let prop = setup.with(jwst.with_stm(), almanac.clone());
let mut odp = SpacecraftODProcess::ckf(prop, ckf, None, almanac.clone());
// Define the prediction step, i.e. how often we want to know the covariance.
let step = 1_i64.minutes();
// Finally, predict, and export the trajectory with covariance to a parquet file.
odp.predict_for(step, prediction_duration)?;
odp.to_parquet("./02_jwst_covar_map.parquet", ExportCfg::default())?;
// === Monte Carlo framework ===
// Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
let my_mc = MonteCarlo::new(
jwst, // Nominal state
jwst_estimate.to_random_variable()?,
"02_jwst".to_string(), // Scenario name
None, // No specific seed specified, so one will be drawn from the computer's entropy.
);
let num_runs = 5_000;
let rslts = my_mc.run_until_epoch(
setup,
almanac.clone(),
jwst.epoch() + prediction_duration,
num_runs,
);
assert_eq!(rslts.runs.len(), num_runs);
// Finally, export these results, computing the eclipse percentage for all of these results.
// For all of the resulting trajectories, we'll want to compute the percentage of penumbra and umbra.
let eclipse_loc = EclipseLocator::cislunar(almanac.clone());
let umbra_event = eclipse_loc.to_umbra_event();
let penumbra_event = eclipse_loc.to_penumbra_event();
rslts.to_parquet(
"02_jwst_monte_carlo.parquet",
Some(vec![&umbra_event, &penumbra_event]),
ExportCfg::default(),
almanac,
)?;
Ok(())
}
§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>
§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.
pub fn describe(
&self,
spk: Option<bool>,
bpc: Option<bool>,
planetary: Option<bool>,
time_scale: Option<TimeScale>,
round_time: Option<bool>,
)
pub fn describe( &self, spk: Option<bool>, bpc: Option<bool>, planetary: 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.
§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.
§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].
pub fn translate_geometric(
&self,
target_frame: Frame,
observer_frame: Frame,
epoch: Epoch,
) -> Result<CartesianState, EphemerisError>
pub fn translate_geometric( &self, target_frame: Frame, observer_frame: Frame, epoch: Epoch, ) -> Result<CartesianState, EphemerisError>
Returns the geometric position vector, velocity vector, and acceleration vector needed to translate the from_frame
to the to_frame
, where the distance is in km, the velocity in km/s, and the acceleration in km/s^2.
pub fn translate_to(
&self,
state: CartesianState,
observer_frame: Frame,
ab_corr: Option<Aberration>,
) -> Result<CartesianState, EphemerisError>
pub fn translate_to( &self, state: CartesianState, observer_frame: Frame, ab_corr: Option<Aberration>, ) -> Result<CartesianState, EphemerisError>
Translates the provided Cartesian state into the requested observer frame
WARNING: This function only performs the translation and no rotation whatsoever. Use the transform_to
function instead to include rotations.
§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_from_to(
&self,
from_frame: Frame,
to_frame: Frame,
epoch: Epoch,
) -> Result<DCM, OrientationError>
pub fn rotate_from_to( &self, from_frame: Frame, to_frame: Frame, epoch: Epoch, ) -> Result<DCM, 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>
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>
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.
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
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