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MetaAlmanac

Struct MetaAlmanac 

pub struct MetaAlmanac {
    pub files: Vec<MetaFile>,
}
Expand description

A structure to set up an Almanac, with automatic downloading, local storage, checksum checking, and more.

§Behavior

If the URI is a local path, relative or absolute, nothing will be fetched from a remote. Relative paths are relative to the execution folder (i.e. the current working directory). If the URI is a remote path, the MetaAlmanac will first check if the file exists locally. If it exists, it will check that the CRC32 checksum of this file matches that of the specs. If it does not match, the file will be downloaded again. If no CRC32 is provided but the file exists, then the MetaAlmanac will fetch the remote file and overwrite the existing file. The downloaded path will be stored in the “AppData” folder.

:type maybe_path: str, optional :rtype: MetaAlmanac

Fields§

§files: Vec<MetaFile>

Implementations§

§

impl MetaAlmanac

pub fn new(path: &str) -> Result<MetaAlmanac, MetaAlmanacError>

Loads the provided path as a Dhall configuration file and processes each file.

Examples found in repository?
nyx-core/examples/06_lunar_orbit_determination/main.rs (line 56)
35fn main() -> Result<(), Box<dyn Error>> {
36    pel::init();
37
38    // ====================== //
39    // === ALMANAC SET UP === //
40    // ====================== //
41
42    // Dynamics models require planetary constants and ephemerides to be defined.
43    // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45    let data_folder: PathBuf = [
46        env!("CARGO_MANIFEST_DIR"),
47        "examples",
48        "06_lunar_orbit_determination",
49    ]
50    .iter()
51    .collect();
52
53    let meta = data_folder.join("metaalmanac.dhall");
54
55    // Load this ephem in the general Almanac we're using for this analysis.
56    let almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
57        .map_err(Box::new)?
58        .process(true)
59        .map_err(Box::new)?;
60
61    // Lock the almanac (an Arc is a read only structure).
62    let almanac = Arc::new(almanac);
63
64    // Build a nominal trajectory
65    // TODO: Switch this to a sequence once the OD over a spacecraft sequence is implemented.
66
67    let epoch = Epoch::from_gregorian_utc_at_noon(2024, 2, 29);
68    let moon_j2000 = almanac.frame_info(MOON_J2000)?;
69
70    // To build the trajectory we need to provide a spacecraft template.
71    let orbiter = Spacecraft::builder()
72        .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0))
73        .srp(SRPData {
74            area_m2: 3.9 * 2.7,
75            coeff_reflectivity: 0.96,
76        })
77        .orbit(Orbit::try_keplerian_altitude(
78            150.0, 0.00212, 33.6, 45.0, 45.0, 0.0, epoch, moon_j2000,
79        )?) // Setting a zero orbit here because it's just a template
80        .build();
81
82    // ========================== //
83    // === BUILD NOMINAL TRAJ === //
84    // ========================== //
85
86    // Set up the spacecraft dynamics.
87
88    // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
89    // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
90    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
91
92    // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
93    // We're using the GRAIL JGGRX model.
94    let mut jggrx_meta = MetaFile {
95        uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
96        crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
97    };
98    // And let's download it if we don't have it yet.
99    jggrx_meta.process(true)?;
100
101    // Build the spherical harmonics.
102    // The harmonics must be computed in the body fixed frame.
103    // We're using the long term prediction of the Moon principal axes frame.
104    let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
105    let sph_harmonics = GravityField::new(GravityFieldData::from_shadr(
106        &jggrx_meta.uri,
107        80,
108        80,
109        true,
110        almanac.frame_info(moon_pa_frame)?,
111    )?);
112
113    // Include the spherical harmonics into the orbital dynamics.
114    orbital_dyn.accel_models.push(sph_harmonics);
115
116    // We define the solar radiation pressure, using the default solar flux and accounting only
117    // for the eclipsing caused by the Earth and Moon.
118    // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
119    let srp_dyn = SolarPressure::new(vec![MOON_J2000], &almanac)?;
120
121    // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
122    // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
123    let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
124
125    println!("{dynamics}");
126
127    let setup = Propagator::rk89(dynamics.clone(), IntegratorOptions::default());
128
129    let truth_traj = setup
130        .with(orbiter, almanac.clone())
131        .for_duration_with_traj(Unit::Day * 2)?
132        .1;
133
134    // ==================== //
135    // === OD SIMULATOR === //
136    // ==================== //
137
138    // Load the Deep Space Network ground stations.
139    // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
140    let ground_station_file = data_folder.join("dsn-network.yaml");
141    let devices = GroundStation::load_named(ground_station_file)?;
142
143    let proc_devices = devices.clone();
144
145    // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
146    // Nyx can build a tracking schedule for you based on the first station with access.
147    let configs: BTreeMap<String, TrkConfig> =
148        TrkConfig::load_named(data_folder.join("tracking-cfg.yaml"))?;
149
150    // Build the tracking arc simulation to generate a "standard measurement".
151    let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
152        devices.clone(),
153        truth_traj.clone(),
154        configs,
155        123, // Set a seed for reproducibility
156    )?;
157
158    trk.build_schedule(almanac.clone())?;
159    let arc = trk.generate_measurements(almanac.clone())?;
160    // Save the simulated tracking data
161    arc.to_parquet_simple("./data/04_output/06_lunar_simulated_tracking.parquet")?;
162
163    // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
164    println!("{arc}");
165
166    // Now that we have simulated measurements, we'll run the orbit determination.
167
168    // ===================== //
169    // === OD ESTIMATION === //
170    // ===================== //
171
172    let sc = SpacecraftUncertainty::builder()
173        .nominal(orbiter)
174        .frame(LocalFrame::RIC)
175        .x_km(0.5)
176        .y_km(0.5)
177        .z_km(0.5)
178        .vx_km_s(5e-3)
179        .vy_km_s(5e-3)
180        .vz_km_s(5e-3)
181        .build();
182
183    // Build the filter initial estimate, which we will reuse in the filter.
184    let initial_estimate = sc.to_estimate()?;
185
186    println!("== FILTER STATE ==\n{orbiter:x}\n{initial_estimate}");
187
188    // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
189    let process_noise = ProcessNoise3D::from_velocity_km_s(
190        &[1e-14, 1e-14, 1e-14],
191        1 * Unit::Hour,
192        10 * Unit::Minute,
193        None,
194    );
195
196    println!("{process_noise}");
197
198    // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
199    let odp = SpacecraftKalmanScalarOD::new(
200        setup,
201        KalmanVariant::ReferenceUpdate,
202        Some(ResidRejectCrit::default()),
203        proc_devices,
204        almanac.clone(),
205    )
206    .with_process_noise(process_noise);
207
208    let od_sol = odp.process_arc(initial_estimate, &arc)?;
209
210    let final_est = od_sol.estimates.last().unwrap();
211
212    println!("{final_est}");
213
214    let ric_err = truth_traj
215        .at(final_est.epoch())?
216        .orbit
217        .ric_difference(&final_est.orbital_state())?;
218    println!("== RIC at end ==");
219    println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
220    println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
221
222    println!(
223        "Num residuals rejected: #{}",
224        od_sol.rejected_residuals().len()
225    );
226    println!(
227        "Percentage within +/-3: {}",
228        od_sol.residual_ratio_within_threshold(3.0).unwrap()
229    );
230    println!("Whitened residuals normal? {}", od_sol.is_normal(None)?);
231    println!("NIS test success? {}", od_sol.is_nis_consistent(None)?);
232
233    od_sol.to_parquet(
234        "./data/04_output/06_lunar_od_results.parquet",
235        ExportCfg::default(),
236    )?;
237
238    let od_trajectory = od_sol.to_traj()?;
239    // Build the RIC difference.
240    od_trajectory.ric_diff_to_parquet(
241        &truth_traj,
242        "./data/04_output/06_lunar_od_truth_error.parquet",
243        ExportCfg::default(),
244    )?;
245
246    Ok(())
247}
More examples
Hide additional examples
nyx-core/examples/04_lro_od/main.rs (line 56)
35fn main() -> Result<(), Box<dyn Error>> {
36    pel::init();
37
38    // ====================== //
39    // === ALMANAC SET UP === //
40    // ====================== //
41
42    // Dynamics models require planetary constants and ephemerides to be defined.
43    // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45    let output_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "../data", "04_output"]
46        .iter()
47        .collect();
48
49    let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
50        .iter()
51        .collect();
52
53    let meta = data_folder.join("lro-dynamics.dhall");
54
55    // Load this ephem in the general Almanac we're using for this analysis.
56    let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
57        .map_err(Box::new)?
58        .process(true)
59        .map_err(Box::new)?;
60
61    let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
62    moon_pc.mu_km3_s2 = 4902.74987;
63    almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
64
65    let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
66    earth.mu_km3_s2 = 398600.436;
67    almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
68
69    // Save this new kernel for reuse.
70    // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
71    almanac
72        .planetary_data
73        .values()
74        .next()
75        .unwrap()
76        .save_as(&data_folder.join("lro-specific.pca"), true)?;
77
78    // Lock the almanac (an Arc is a read only structure).
79    let almanac = Arc::new(almanac);
80
81    // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
82    // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
83    // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
84    // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
85    let lro_frame = Frame::from_ephem_j2000(-85);
86
87    // To build the trajectory we need to provide a spacecraft template.
88    let sc_template = Spacecraft::builder()
89        .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
90        .srp(SRPData {
91            // SRP configuration is arbitrary, but we will be estimating it anyway.
92            area_m2: 3.9 * 2.7,
93            coeff_reflectivity: 0.96,
94        })
95        .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
96        .build();
97    // Now we can build the trajectory from the BSP file.
98    // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
99    let traj_as_flown = Traj::from_bsp(
100        lro_frame,
101        MOON_J2000,
102        almanac.clone(),
103        sc_template,
104        5.seconds(),
105        Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
106        Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
107        Aberration::LT,
108        Some("LRO".to_string()),
109    )?;
110
111    println!("{traj_as_flown}");
112
113    // ====================== //
114    // === MODEL MATCHING === //
115    // ====================== //
116
117    // Set up the spacecraft dynamics.
118
119    // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
120    // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
121    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
122
123    // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
124    // We're using the GRAIL JGGRX model.
125    let mut jggrx_meta = MetaFile {
126        uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
127        crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
128    };
129    // And let's download it if we don't have it yet.
130    jggrx_meta.process(true)?;
131
132    // Build the spherical harmonics.
133    // The harmonics must be computed in the body fixed frame.
134    // We're using the long term prediction of the Moon principal axes frame.
135    let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
136    let sph_harmonics = GravityField::new(GravityFieldData::from_shadr(
137        &jggrx_meta.uri,
138        80,
139        80,
140        true,
141        almanac.frame_info(moon_pa_frame)?,
142    )?);
143
144    // Include the spherical harmonics into the orbital dynamics.
145    orbital_dyn.accel_models.push(sph_harmonics);
146
147    // We define the solar radiation pressure, using the default solar flux and accounting only
148    // for the eclipsing caused by the Earth and Moon.
149    // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
150    let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], &almanac)?;
151
152    // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
153    // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
154    let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
155
156    println!("{dynamics}");
157
158    // Now we can build the propagator.
159    let setup = Propagator::default_dp78(dynamics.clone());
160
161    // For reference, let's build the trajectory with Nyx's models from that LRO state.
162    let (sim_final, traj_as_sim) = setup
163        .with(*traj_as_flown.first(), almanac.clone())
164        .until_epoch_with_traj(traj_as_flown.last().epoch())?;
165
166    println!("SIM INIT:  {:x}", traj_as_flown.first());
167    println!("SIM FINAL: {sim_final:x}");
168    // Compute RIC difference between SIM and LRO ephem
169    let sim_lro_delta = sim_final
170        .orbit
171        .ric_difference(&traj_as_flown.last().orbit)?;
172    println!("{traj_as_sim}");
173    println!(
174        "SIM v LRO - RIC Position (m): {:.3}",
175        sim_lro_delta.radius_km * 1e3
176    );
177    println!(
178        "SIM v LRO - RIC Velocity (m/s): {:.3}",
179        sim_lro_delta.velocity_km_s * 1e3
180    );
181
182    traj_as_sim.ric_diff_to_parquet(
183        &traj_as_flown,
184        output_folder.join("./04_lro_sim_truth_error.parquet"),
185        ExportCfg::default(),
186    )?;
187
188    // ==================== //
189    // === OD SIMULATOR === //
190    // ==================== //
191
192    // 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
193    // and the truth LRO state.
194
195    // Therefore, we will actually run an estimation from a dispersed LRO state.
196    // The sc_seed is the true LRO state from the BSP.
197    let sc_seed = *traj_as_flown.first();
198
199    // Load the Deep Space Network ground stations.
200    // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
201    let ground_station_file: PathBuf = [
202        env!("CARGO_MANIFEST_DIR"),
203        "examples",
204        "04_lro_od",
205        "dsn-network.yaml",
206    ]
207    .iter()
208    .collect();
209
210    let devices = GroundStation::load_named(ground_station_file)?;
211
212    let mut proc_devices = devices.clone();
213
214    // Increase the noise in the devices to accept more measurements.
215    for gs in proc_devices.values_mut() {
216        if let Some(noise) = &mut gs
217            .stochastic_noises
218            .as_mut()
219            .unwrap()
220            .get_mut(&MeasurementType::Range)
221        {
222            *noise.white_noise.as_mut().unwrap() *= 3.0;
223        }
224    }
225
226    // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
227    // Nyx can build a tracking schedule for you based on the first station with access.
228    let trkconfg_yaml: PathBuf = [
229        env!("CARGO_MANIFEST_DIR"),
230        "examples",
231        "04_lro_od",
232        "tracking-cfg.yaml",
233    ]
234    .iter()
235    .collect();
236
237    let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
238
239    // Build the tracking arc simulation to generate a "standard measurement".
240    let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
241        devices.clone(),
242        traj_as_flown.clone(),
243        configs,
244        123, // Set a seed for reproducibility
245    )?;
246
247    trk.build_schedule(almanac.clone())?;
248    let arc = trk.generate_measurements(almanac.clone())?;
249    // Save the simulated tracking data
250    arc.to_parquet_simple(output_folder.join("04_lro_simulated_tracking.parquet"))?;
251
252    // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
253    println!("{arc}");
254
255    // Now that we have simulated measurements, we'll run the orbit determination.
256
257    // ===================== //
258    // === OD ESTIMATION === //
259    // ===================== //
260
261    let sc = SpacecraftUncertainty::builder()
262        .nominal(sc_seed)
263        .frame(LocalFrame::RIC)
264        .x_km(0.5)
265        .y_km(0.5)
266        .z_km(0.5)
267        .vx_km_s(5e-3)
268        .vy_km_s(5e-3)
269        .vz_km_s(5e-3)
270        .build();
271
272    // Build the filter initial estimate, which we will reuse in the filter.
273    let mut initial_estimate = sc.to_estimate()?;
274    initial_estimate.covar *= 3.0;
275
276    println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
277
278    // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
279    let process_noise = ProcessNoise3D::from_velocity_km_s(
280        &[1e-12, 1e-12, 1e-12],
281        1 * Unit::Hour,
282        10 * Unit::Minute,
283        None,
284    );
285
286    println!("{process_noise}");
287
288    // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
289    let odp = SpacecraftKalmanOD::new(
290        setup,
291        KalmanVariant::ReferenceUpdate,
292        Some(ResidRejectCrit::default()),
293        proc_devices,
294        almanac.clone(),
295    )
296    .with_process_noise(process_noise);
297
298    let od_sol = odp.process_arc(initial_estimate, &arc)?;
299
300    let final_est = od_sol.estimates.last().unwrap();
301
302    println!("{final_est}");
303
304    let ric_err = traj_as_flown
305        .at(final_est.epoch())?
306        .orbit
307        .ric_difference(&final_est.orbital_state())?;
308    println!("== RIC at end ==");
309    println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
310    println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
311
312    println!(
313        "Num residuals rejected: #{}",
314        od_sol.rejected_residuals().len()
315    );
316    println!(
317        "Percentage within +/-3: {}",
318        od_sol.residual_ratio_within_threshold(3.0).unwrap()
319    );
320    println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
321
322    od_sol.to_parquet(
323        output_folder.join("04_lro_od_results.parquet"),
324        ExportCfg::default(),
325    )?;
326
327    // Create the ephemeris
328    let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
329    let ephem_start = ephem.start_epoch().unwrap();
330    let ephem_end = ephem.end_epoch().unwrap();
331    // Check that the covariance is PSD throughout the ephemeris by interpolating it.
332    for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
333        ephem
334            .covar_at(
335                epoch,
336                anise::ephemerides::ephemeris::LocalFrame::RIC,
337                &almanac,
338            )
339            .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
340    }
341    // Export as BSP!
342    ephem
343        .write_spice_bsp(
344            -85,
345            output_folder.join("04_lro_rebuilt.bsp").to_str().unwrap(),
346            None,
347        )
348        .expect("could not built BSP");
349    let new_almanac = Almanac::default()
350        .load(output_folder.join("04_lro_rebuilt.bsp").to_str().unwrap())
351        .unwrap();
352    new_almanac.describe(None, None, None, None, None, None, None, None);
353    let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
354
355    assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
356    assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
357
358    // In our case, we have the truth trajectory from NASA.
359    // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
360    // Export the OD trajectory first.
361    let od_trajectory = od_sol.to_traj()?;
362    // Build the RIC difference.
363    od_trajectory.ric_diff_to_parquet(
364        &traj_as_flown,
365        output_folder.join("04_lro_od_truth_error.parquet"),
366        ExportCfg::default(),
367    )?;
368
369    Ok(())
370}

pub fn process(&mut self, autodelete: bool) -> Result<Almanac, AlmanacError>

Fetch all of the URIs and return a loaded Almanac When downloading the data, ANISE will create a temporarily lock file to prevent race conditions where multiple processes download the data at the same time. Set autodelete to true to delete this lock file if a dead lock is detected after 10 seconds. Set this flag to false if you have more than ten processes which may attempt to download files in parallel.

Examples found in repository?
nyx-core/examples/06_lunar_orbit_determination/main.rs (line 58)
35fn main() -> Result<(), Box<dyn Error>> {
36    pel::init();
37
38    // ====================== //
39    // === ALMANAC SET UP === //
40    // ====================== //
41
42    // Dynamics models require planetary constants and ephemerides to be defined.
43    // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45    let data_folder: PathBuf = [
46        env!("CARGO_MANIFEST_DIR"),
47        "examples",
48        "06_lunar_orbit_determination",
49    ]
50    .iter()
51    .collect();
52
53    let meta = data_folder.join("metaalmanac.dhall");
54
55    // Load this ephem in the general Almanac we're using for this analysis.
56    let almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
57        .map_err(Box::new)?
58        .process(true)
59        .map_err(Box::new)?;
60
61    // Lock the almanac (an Arc is a read only structure).
62    let almanac = Arc::new(almanac);
63
64    // Build a nominal trajectory
65    // TODO: Switch this to a sequence once the OD over a spacecraft sequence is implemented.
66
67    let epoch = Epoch::from_gregorian_utc_at_noon(2024, 2, 29);
68    let moon_j2000 = almanac.frame_info(MOON_J2000)?;
69
70    // To build the trajectory we need to provide a spacecraft template.
71    let orbiter = Spacecraft::builder()
72        .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0))
73        .srp(SRPData {
74            area_m2: 3.9 * 2.7,
75            coeff_reflectivity: 0.96,
76        })
77        .orbit(Orbit::try_keplerian_altitude(
78            150.0, 0.00212, 33.6, 45.0, 45.0, 0.0, epoch, moon_j2000,
79        )?) // Setting a zero orbit here because it's just a template
80        .build();
81
82    // ========================== //
83    // === BUILD NOMINAL TRAJ === //
84    // ========================== //
85
86    // Set up the spacecraft dynamics.
87
88    // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
89    // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
90    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
91
92    // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
93    // We're using the GRAIL JGGRX model.
94    let mut jggrx_meta = MetaFile {
95        uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
96        crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
97    };
98    // And let's download it if we don't have it yet.
99    jggrx_meta.process(true)?;
100
101    // Build the spherical harmonics.
102    // The harmonics must be computed in the body fixed frame.
103    // We're using the long term prediction of the Moon principal axes frame.
104    let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
105    let sph_harmonics = GravityField::new(GravityFieldData::from_shadr(
106        &jggrx_meta.uri,
107        80,
108        80,
109        true,
110        almanac.frame_info(moon_pa_frame)?,
111    )?);
112
113    // Include the spherical harmonics into the orbital dynamics.
114    orbital_dyn.accel_models.push(sph_harmonics);
115
116    // We define the solar radiation pressure, using the default solar flux and accounting only
117    // for the eclipsing caused by the Earth and Moon.
118    // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
119    let srp_dyn = SolarPressure::new(vec![MOON_J2000], &almanac)?;
120
121    // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
122    // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
123    let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
124
125    println!("{dynamics}");
126
127    let setup = Propagator::rk89(dynamics.clone(), IntegratorOptions::default());
128
129    let truth_traj = setup
130        .with(orbiter, almanac.clone())
131        .for_duration_with_traj(Unit::Day * 2)?
132        .1;
133
134    // ==================== //
135    // === OD SIMULATOR === //
136    // ==================== //
137
138    // Load the Deep Space Network ground stations.
139    // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
140    let ground_station_file = data_folder.join("dsn-network.yaml");
141    let devices = GroundStation::load_named(ground_station_file)?;
142
143    let proc_devices = devices.clone();
144
145    // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
146    // Nyx can build a tracking schedule for you based on the first station with access.
147    let configs: BTreeMap<String, TrkConfig> =
148        TrkConfig::load_named(data_folder.join("tracking-cfg.yaml"))?;
149
150    // Build the tracking arc simulation to generate a "standard measurement".
151    let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
152        devices.clone(),
153        truth_traj.clone(),
154        configs,
155        123, // Set a seed for reproducibility
156    )?;
157
158    trk.build_schedule(almanac.clone())?;
159    let arc = trk.generate_measurements(almanac.clone())?;
160    // Save the simulated tracking data
161    arc.to_parquet_simple("./data/04_output/06_lunar_simulated_tracking.parquet")?;
162
163    // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
164    println!("{arc}");
165
166    // Now that we have simulated measurements, we'll run the orbit determination.
167
168    // ===================== //
169    // === OD ESTIMATION === //
170    // ===================== //
171
172    let sc = SpacecraftUncertainty::builder()
173        .nominal(orbiter)
174        .frame(LocalFrame::RIC)
175        .x_km(0.5)
176        .y_km(0.5)
177        .z_km(0.5)
178        .vx_km_s(5e-3)
179        .vy_km_s(5e-3)
180        .vz_km_s(5e-3)
181        .build();
182
183    // Build the filter initial estimate, which we will reuse in the filter.
184    let initial_estimate = sc.to_estimate()?;
185
186    println!("== FILTER STATE ==\n{orbiter:x}\n{initial_estimate}");
187
188    // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
189    let process_noise = ProcessNoise3D::from_velocity_km_s(
190        &[1e-14, 1e-14, 1e-14],
191        1 * Unit::Hour,
192        10 * Unit::Minute,
193        None,
194    );
195
196    println!("{process_noise}");
197
198    // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
199    let odp = SpacecraftKalmanScalarOD::new(
200        setup,
201        KalmanVariant::ReferenceUpdate,
202        Some(ResidRejectCrit::default()),
203        proc_devices,
204        almanac.clone(),
205    )
206    .with_process_noise(process_noise);
207
208    let od_sol = odp.process_arc(initial_estimate, &arc)?;
209
210    let final_est = od_sol.estimates.last().unwrap();
211
212    println!("{final_est}");
213
214    let ric_err = truth_traj
215        .at(final_est.epoch())?
216        .orbit
217        .ric_difference(&final_est.orbital_state())?;
218    println!("== RIC at end ==");
219    println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
220    println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
221
222    println!(
223        "Num residuals rejected: #{}",
224        od_sol.rejected_residuals().len()
225    );
226    println!(
227        "Percentage within +/-3: {}",
228        od_sol.residual_ratio_within_threshold(3.0).unwrap()
229    );
230    println!("Whitened residuals normal? {}", od_sol.is_normal(None)?);
231    println!("NIS test success? {}", od_sol.is_nis_consistent(None)?);
232
233    od_sol.to_parquet(
234        "./data/04_output/06_lunar_od_results.parquet",
235        ExportCfg::default(),
236    )?;
237
238    let od_trajectory = od_sol.to_traj()?;
239    // Build the RIC difference.
240    od_trajectory.ric_diff_to_parquet(
241        &truth_traj,
242        "./data/04_output/06_lunar_od_truth_error.parquet",
243        ExportCfg::default(),
244    )?;
245
246    Ok(())
247}
More examples
Hide additional examples
nyx-core/examples/04_lro_od/main.rs (line 58)
35fn main() -> Result<(), Box<dyn Error>> {
36    pel::init();
37
38    // ====================== //
39    // === ALMANAC SET UP === //
40    // ====================== //
41
42    // Dynamics models require planetary constants and ephemerides to be defined.
43    // Let's start by grabbing those by using ANISE's MetaAlmanac.
44
45    let output_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "../data", "04_output"]
46        .iter()
47        .collect();
48
49    let data_folder: PathBuf = [env!("CARGO_MANIFEST_DIR"), "examples", "04_lro_od"]
50        .iter()
51        .collect();
52
53    let meta = data_folder.join("lro-dynamics.dhall");
54
55    // Load this ephem in the general Almanac we're using for this analysis.
56    let mut almanac = MetaAlmanac::new(meta.to_string_lossy().as_ref())
57        .map_err(Box::new)?
58        .process(true)
59        .map_err(Box::new)?;
60
61    let mut moon_pc = almanac.get_planetary_data_from_id(MOON).unwrap();
62    moon_pc.mu_km3_s2 = 4902.74987;
63    almanac.set_planetary_data_from_id(MOON, moon_pc).unwrap();
64
65    let mut earth = almanac.get_planetary_data_from_id(EARTH).unwrap();
66    earth.mu_km3_s2 = 398600.436;
67    almanac.set_planetary_data_from_id(EARTH, earth).unwrap();
68
69    // Save this new kernel for reuse.
70    // In an operational context, this would be part of the "Lock" process, and should not change throughout the mission.
71    almanac
72        .planetary_data
73        .values()
74        .next()
75        .unwrap()
76        .save_as(&data_folder.join("lro-specific.pca"), true)?;
77
78    // Lock the almanac (an Arc is a read only structure).
79    let almanac = Arc::new(almanac);
80
81    // Orbit determination requires a Trajectory structure, which can be saved as parquet file.
82    // In our case, the trajectory comes from the BSP file, so we need to build a Trajectory from the almanac directly.
83    // To query the Almanac, we need to build the LRO frame in the J2000 orientation in our case.
84    // Inspecting the LRO BSP in the ANISE GUI shows us that NASA has assigned ID -85 to LRO.
85    let lro_frame = Frame::from_ephem_j2000(-85);
86
87    // To build the trajectory we need to provide a spacecraft template.
88    let sc_template = Spacecraft::builder()
89        .mass(Mass::from_dry_and_prop_masses(1018.0, 900.0)) // Launch masses
90        .srp(SRPData {
91            // SRP configuration is arbitrary, but we will be estimating it anyway.
92            area_m2: 3.9 * 2.7,
93            coeff_reflectivity: 0.96,
94        })
95        .orbit(Orbit::zero(MOON_J2000)) // Setting a zero orbit here because it's just a template
96        .build();
97    // Now we can build the trajectory from the BSP file.
98    // We'll arbitrarily set the tracking arc to 24 hours with a five second time step.
99    let traj_as_flown = Traj::from_bsp(
100        lro_frame,
101        MOON_J2000,
102        almanac.clone(),
103        sc_template,
104        5.seconds(),
105        Some(Epoch::from_str("2024-01-01 00:00:00 UTC")?),
106        Some(Epoch::from_str("2024-01-02 00:00:00 UTC")?),
107        Aberration::LT,
108        Some("LRO".to_string()),
109    )?;
110
111    println!("{traj_as_flown}");
112
113    // ====================== //
114    // === MODEL MATCHING === //
115    // ====================== //
116
117    // Set up the spacecraft dynamics.
118
119    // Specify that the orbital dynamics must account for the graviational pull of the Earth and the Sun.
120    // The gravity of the Moon will also be accounted for since the spaceraft in a lunar orbit.
121    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![EARTH, SUN, JUPITER_BARYCENTER]);
122
123    // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
124    // We're using the GRAIL JGGRX model.
125    let mut jggrx_meta = MetaFile {
126        uri: "http://public-data.nyxspace.com/nyx/models/Luna_jggrx_1500e_sha.tab.gz".to_string(),
127        crc32: Some(0x6bcacda8), // Specifying the CRC32 avoids redownloading it if it's cached.
128    };
129    // And let's download it if we don't have it yet.
130    jggrx_meta.process(true)?;
131
132    // Build the spherical harmonics.
133    // The harmonics must be computed in the body fixed frame.
134    // We're using the long term prediction of the Moon principal axes frame.
135    let moon_pa_frame = MOON_PA_FRAME.with_orient(31008);
136    let sph_harmonics = GravityField::new(GravityFieldData::from_shadr(
137        &jggrx_meta.uri,
138        80,
139        80,
140        true,
141        almanac.frame_info(moon_pa_frame)?,
142    )?);
143
144    // Include the spherical harmonics into the orbital dynamics.
145    orbital_dyn.accel_models.push(sph_harmonics);
146
147    // We define the solar radiation pressure, using the default solar flux and accounting only
148    // for the eclipsing caused by the Earth and Moon.
149    // Note that by default, enabling the SolarPressure model will also enable the estimation of the coefficient of reflectivity.
150    let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], &almanac)?;
151
152    // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
153    // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
154    let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
155
156    println!("{dynamics}");
157
158    // Now we can build the propagator.
159    let setup = Propagator::default_dp78(dynamics.clone());
160
161    // For reference, let's build the trajectory with Nyx's models from that LRO state.
162    let (sim_final, traj_as_sim) = setup
163        .with(*traj_as_flown.first(), almanac.clone())
164        .until_epoch_with_traj(traj_as_flown.last().epoch())?;
165
166    println!("SIM INIT:  {:x}", traj_as_flown.first());
167    println!("SIM FINAL: {sim_final:x}");
168    // Compute RIC difference between SIM and LRO ephem
169    let sim_lro_delta = sim_final
170        .orbit
171        .ric_difference(&traj_as_flown.last().orbit)?;
172    println!("{traj_as_sim}");
173    println!(
174        "SIM v LRO - RIC Position (m): {:.3}",
175        sim_lro_delta.radius_km * 1e3
176    );
177    println!(
178        "SIM v LRO - RIC Velocity (m/s): {:.3}",
179        sim_lro_delta.velocity_km_s * 1e3
180    );
181
182    traj_as_sim.ric_diff_to_parquet(
183        &traj_as_flown,
184        output_folder.join("./04_lro_sim_truth_error.parquet"),
185        ExportCfg::default(),
186    )?;
187
188    // ==================== //
189    // === OD SIMULATOR === //
190    // ==================== //
191
192    // 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
193    // and the truth LRO state.
194
195    // Therefore, we will actually run an estimation from a dispersed LRO state.
196    // The sc_seed is the true LRO state from the BSP.
197    let sc_seed = *traj_as_flown.first();
198
199    // Load the Deep Space Network ground stations.
200    // Nyx allows you to build these at runtime but it's pretty static so we can just load them from YAML.
201    let ground_station_file: PathBuf = [
202        env!("CARGO_MANIFEST_DIR"),
203        "examples",
204        "04_lro_od",
205        "dsn-network.yaml",
206    ]
207    .iter()
208    .collect();
209
210    let devices = GroundStation::load_named(ground_station_file)?;
211
212    let mut proc_devices = devices.clone();
213
214    // Increase the noise in the devices to accept more measurements.
215    for gs in proc_devices.values_mut() {
216        if let Some(noise) = &mut gs
217            .stochastic_noises
218            .as_mut()
219            .unwrap()
220            .get_mut(&MeasurementType::Range)
221        {
222            *noise.white_noise.as_mut().unwrap() *= 3.0;
223        }
224    }
225
226    // Typical OD software requires that you specify your own tracking schedule or you'll have overlapping measurements.
227    // Nyx can build a tracking schedule for you based on the first station with access.
228    let trkconfg_yaml: PathBuf = [
229        env!("CARGO_MANIFEST_DIR"),
230        "examples",
231        "04_lro_od",
232        "tracking-cfg.yaml",
233    ]
234    .iter()
235    .collect();
236
237    let configs: BTreeMap<String, TrkConfig> = TrkConfig::load_named(trkconfg_yaml)?;
238
239    // Build the tracking arc simulation to generate a "standard measurement".
240    let mut trk = TrackingArcSim::<Spacecraft, GroundStation>::with_seed(
241        devices.clone(),
242        traj_as_flown.clone(),
243        configs,
244        123, // Set a seed for reproducibility
245    )?;
246
247    trk.build_schedule(almanac.clone())?;
248    let arc = trk.generate_measurements(almanac.clone())?;
249    // Save the simulated tracking data
250    arc.to_parquet_simple(output_folder.join("04_lro_simulated_tracking.parquet"))?;
251
252    // We'll note that in our case, we have continuous coverage of LRO when the vehicle is not behind the Moon.
253    println!("{arc}");
254
255    // Now that we have simulated measurements, we'll run the orbit determination.
256
257    // ===================== //
258    // === OD ESTIMATION === //
259    // ===================== //
260
261    let sc = SpacecraftUncertainty::builder()
262        .nominal(sc_seed)
263        .frame(LocalFrame::RIC)
264        .x_km(0.5)
265        .y_km(0.5)
266        .z_km(0.5)
267        .vx_km_s(5e-3)
268        .vy_km_s(5e-3)
269        .vz_km_s(5e-3)
270        .build();
271
272    // Build the filter initial estimate, which we will reuse in the filter.
273    let mut initial_estimate = sc.to_estimate()?;
274    initial_estimate.covar *= 3.0;
275
276    println!("== FILTER STATE ==\n{sc_seed:x}\n{initial_estimate}");
277
278    // Build the SNC in the Moon J2000 frame, specified as a velocity noise over time.
279    let process_noise = ProcessNoise3D::from_velocity_km_s(
280        &[1e-12, 1e-12, 1e-12],
281        1 * Unit::Hour,
282        10 * Unit::Minute,
283        None,
284    );
285
286    println!("{process_noise}");
287
288    // We'll set up the OD process to reject measurements whose residuals are move than 3 sigmas away from what we expect.
289    let odp = SpacecraftKalmanOD::new(
290        setup,
291        KalmanVariant::ReferenceUpdate,
292        Some(ResidRejectCrit::default()),
293        proc_devices,
294        almanac.clone(),
295    )
296    .with_process_noise(process_noise);
297
298    let od_sol = odp.process_arc(initial_estimate, &arc)?;
299
300    let final_est = od_sol.estimates.last().unwrap();
301
302    println!("{final_est}");
303
304    let ric_err = traj_as_flown
305        .at(final_est.epoch())?
306        .orbit
307        .ric_difference(&final_est.orbital_state())?;
308    println!("== RIC at end ==");
309    println!("RIC Position (m): {:.3}", ric_err.radius_km * 1e3);
310    println!("RIC Velocity (m/s): {:.3}", ric_err.velocity_km_s * 1e3);
311
312    println!(
313        "Num residuals rejected: #{}",
314        od_sol.rejected_residuals().len()
315    );
316    println!(
317        "Percentage within +/-3: {}",
318        od_sol.residual_ratio_within_threshold(3.0).unwrap()
319    );
320    println!("Ratios normal? {}", od_sol.is_normal(None).unwrap());
321
322    od_sol.to_parquet(
323        output_folder.join("04_lro_od_results.parquet"),
324        ExportCfg::default(),
325    )?;
326
327    // Create the ephemeris
328    let ephem = od_sol.to_ephemeris("LRO rebuilt".to_string());
329    let ephem_start = ephem.start_epoch().unwrap();
330    let ephem_end = ephem.end_epoch().unwrap();
331    // Check that the covariance is PSD throughout the ephemeris by interpolating it.
332    for epoch in TimeSeries::inclusive(ephem_start, ephem_end, Unit::Minute * 5) {
333        ephem
334            .covar_at(
335                epoch,
336                anise::ephemerides::ephemeris::LocalFrame::RIC,
337                &almanac,
338            )
339            .unwrap_or_else(|e| panic!("covar not PSD at {epoch}: {e}"));
340    }
341    // Export as BSP!
342    ephem
343        .write_spice_bsp(
344            -85,
345            output_folder.join("04_lro_rebuilt.bsp").to_str().unwrap(),
346            None,
347        )
348        .expect("could not built BSP");
349    let new_almanac = Almanac::default()
350        .load(output_folder.join("04_lro_rebuilt.bsp").to_str().unwrap())
351        .unwrap();
352    new_almanac.describe(None, None, None, None, None, None, None, None);
353    let (spk_start, spk_end) = new_almanac.spk_domain(-85).unwrap();
354
355    assert!((ephem_start - spk_start).abs() < Unit::Microsecond * 1);
356    assert!((ephem_end - spk_end).abs() < Unit::Microsecond * 1);
357
358    // In our case, we have the truth trajectory from NASA.
359    // So we can compute the RIC state difference between the real LRO ephem and what we've just estimated.
360    // Export the OD trajectory first.
361    let od_trajectory = od_sol.to_traj()?;
362    // Build the RIC difference.
363    od_trajectory.ric_diff_to_parquet(
364        &traj_as_flown,
365        output_folder.join("04_lro_od_truth_error.parquet"),
366        ExportCfg::default(),
367    )?;
368
369    Ok(())
370}

pub fn latest() -> Result<Almanac, AlmanacError>

Returns an Almanac loaded from the latest NAIF data via the default MetaAlmanac. The MetaAlmanac will download the DE440s.bsp file, the PCK0008.PCA, the full Moon Principal Axis BPC (moon_pa_de440_200625) and the latest high precision Earth kernel from JPL.

§File list
§Reproducibility

Note that the earth_latest_high_prec.bpc file is updated daily (or so). As such, if queried at some future time, the Earth rotation parameters may have changed between two queries.

Examples found in repository?
nyx-core/examples/03_geo_analysis/stationkeeping.rs (line 31)
28fn main() -> Result<(), Box<dyn Error>> {
29    pel::init();
30    // Set up the dynamics like in the orbit raise.
31    let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
32    let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
33
34    // Define the GEO orbit, and we're just going to maintain it very tightly.
35    let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
36    let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
37    println!("{orbit:x}");
38
39    let sc = Spacecraft::builder()
40        .orbit(orbit)
41        .mass(Mass::from_dry_and_prop_masses(1000.0, 1000.0)) // 1000 kg of dry mass and prop, totalling 2.0 tons
42        .srp(SRPData::from_area(3.0 * 6.0)) // Assuming 1 kW/m^2 or 18 kW, giving a margin of 4.35 kW for on-propulsion consumption
43        .thruster(Thruster {
44            // "NEXT-STEP" row in Table 2
45            isp_s: 4435.0,
46            thrust_N: 0.472,
47        })
48        .mode(GuidanceMode::Thrust) // Start thrusting immediately.
49        .build();
50
51    // Set up the spacecraft dynamics like in the orbit raise example.
52
53    let prop_time = 30.0 * Unit::Day;
54
55    // Define the guidance law -- we're just using a Ruggiero controller as demonstrated in AAS-2004-5089.
56    let objectives = &[
57        Objective::within_tolerance(
58            StateParameter::Element(OrbitalElement::SemiMajorAxis),
59            42_165.0,
60            20.0,
61        ),
62        Objective::within_tolerance(
63            StateParameter::Element(OrbitalElement::Eccentricity),
64            0.001,
65            5e-5,
66        ),
67        Objective::within_tolerance(
68            StateParameter::Element(OrbitalElement::Inclination),
69            0.05,
70            1e-2,
71        ),
72    ];
73
74    let ruggiero_ctrl = Ruggiero::from_max_eclipse(objectives, sc, 0.2)?;
75    println!("{ruggiero_ctrl}");
76
77    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
78
79    let mut jgm3_meta = MetaFile {
80        uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
81        crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
82    };
83    jgm3_meta.process(true)?;
84
85    let harmonics = GravityField::new(GravityFieldData::from_cof(
86        &jgm3_meta.uri,
87        8,
88        8,
89        true,
90        almanac.frame_info(IAU_EARTH_FRAME)?,
91    )?);
92    orbital_dyn.accel_models.push(harmonics);
93
94    let srp_dyn = SolarPressure::default_flux(EARTH_J2000, &almanac)?;
95    let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
96        .with_guidance_law(ruggiero_ctrl.clone());
97
98    println!("{sc_dynamics}");
99
100    // Finally, let's use the Monte Carlo framework built into Nyx to propagate spacecraft.
101
102    // Let's start by defining the dispersion.
103    // 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.
104    // Note that additional validation on the MVN is in progress -- https://github.com/nyx-space/nyx/issues/339.
105    let mc_rv = MvnSpacecraft::new(
106        sc,
107        vec![StateDispersion::zero_mean(
108            StateParameter::Element(OrbitalElement::SemiMajorAxis),
109            3.0,
110        )],
111    )?;
112
113    let my_mc = MonteCarlo::new(
114        sc, // Nominal state
115        mc_rv,
116        "03_geo_sk".to_string(), // Scenario name
117        None, // No specific seed specified, so one will be drawn from the computer's entropy.
118    );
119
120    // Build the propagator setup.
121    let setup = Propagator::rk89(
122        sc_dynamics.clone(),
123        IntegratorOptions::builder()
124            .min_step(10.0_f64.seconds())
125            .error_ctrl(ErrorControl::RSSCartesianStep)
126            .build(),
127    );
128
129    let num_runs = 25;
130    let rslts = my_mc.run_until_epoch(setup, almanac.clone(), sc.epoch() + prop_time, num_runs);
131
132    assert_eq!(rslts.runs.len(), num_runs);
133
134    rslts.to_parquet("03_geo_sk.parquet", ExportCfg::default())?;
135
136    Ok(())
137}
More examples
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nyx-core/examples/03_geo_analysis/raise.rs (line 39)
27fn main() -> Result<(), Box<dyn Error>> {
28    pel::init();
29
30    // Dynamics models require planetary constants and ephemerides to be defined.
31    // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
32    // This will automatically download the DE440s planetary ephemeris,
33    // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
34    // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
35    // planetary constants kernels.
36    // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
37    // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
38    // references to many functions.
39    let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
40    // Fetch the EME2000 frame from the Almabac
41    let eme2k = almanac.frame_info(EARTH_J2000).unwrap();
42    // Define the orbit epoch
43    let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
44
45    // Build the spacecraft itself.
46    // Using slide 6 of https://aerospace.org/sites/default/files/2018-11/Davis-Mayberry_HPSEP_11212018.pdf
47    // for the "next gen" SEP characteristics.
48
49    // GTO start
50    let orbit = Orbit::keplerian(24505.9, 0.725, 7.05, 0.0, 0.0, 0.0, epoch, eme2k);
51
52    let sc = Spacecraft::builder()
53        .orbit(orbit)
54        .mass(Mass::from_dry_and_prop_masses(1000.0, 1000.0)) // 1000 kg of dry mass and prop, totalling 2.0 tons
55        .srp(SRPData::from_area(3.0 * 6.0)) // Assuming 1 kW/m^2 or 18 kW, giving a margin of 4.35 kW for on-propulsion consumption
56        .thruster(Thruster {
57            // "NEXT-STEP" row in Table 2
58            isp_s: 4435.0,
59            thrust_N: 0.472,
60        })
61        .mode(GuidanceMode::Thrust) // Start thrusting immediately.
62        .build();
63
64    let prop_time = 180.0 * Unit::Day;
65
66    // Define the guidance law -- we're just using a Ruggiero controller as demonstrated in AAS-2004-5089.
67    let objectives = &[
68        Objective::within_tolerance(
69            StateParameter::Element(OrbitalElement::SemiMajorAxis),
70            42_165.0,
71            20.0,
72        ),
73        Objective::within_tolerance(
74            StateParameter::Element(OrbitalElement::Eccentricity),
75            0.001,
76            5e-5,
77        ),
78        Objective::within_tolerance(
79            StateParameter::Element(OrbitalElement::Inclination),
80            0.05,
81            1e-2,
82        ),
83    ];
84
85    // Ensure that we only thrust if we have more than 20% illumination.
86    let ruggiero_ctrl = Ruggiero::from_max_eclipse(objectives, sc, 0.2).unwrap();
87    println!("{ruggiero_ctrl}");
88
89    // Define the high fidelity dynamics
90
91    // Set up the spacecraft dynamics.
92
93    // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
94    // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
95    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
96
97    // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
98    // We're using the JGM3 model here, which is the default in GMAT.
99    let mut jgm3_meta = MetaFile {
100        uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
101        crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
102    };
103    // And let's download it if we don't have it yet.
104    jgm3_meta.process(true)?;
105
106    // Build the spherical harmonics.
107    // The harmonics must be computed in the body fixed frame.
108    // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
109    let harmonics = GravityField::new(
110        GravityFieldData::from_cof(
111            &jgm3_meta.uri,
112            8,
113            8,
114            true,
115            almanac.frame_info(IAU_EARTH_FRAME)?,
116        )
117        .unwrap(),
118    );
119
120    // Include the spherical harmonics into the orbital dynamics.
121    orbital_dyn.accel_models.push(harmonics);
122
123    // We define the solar radiation pressure, using the default solar flux and accounting only
124    // for the eclipsing caused by the Earth.
125    let srp_dyn = SolarPressure::default_flux(EARTH_J2000, &almanac)?;
126
127    // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
128    // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
129    let sc_dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn)
130        .with_guidance_law(ruggiero_ctrl.clone());
131
132    println!("{orbit:x}");
133
134    // We specify a minimum step in the propagator because the Ruggiero control would otherwise drive this step very low.
135    let (final_state, traj) = Propagator::rk89(
136        sc_dynamics.clone(),
137        IntegratorOptions::builder()
138            .min_step(10.0_f64.seconds())
139            .error_ctrl(ErrorControl::RSSCartesianStep)
140            .build(),
141    )
142    .with(sc, almanac.clone())
143    .for_duration_with_traj(prop_time)?;
144
145    let prop_usage = sc.mass.prop_mass_kg - final_state.mass.prop_mass_kg;
146    println!("{:x}", final_state.orbit);
147    println!("prop usage: {prop_usage:.3} kg");
148
149    // Finally, export the results for analysis, including the penumbra percentage throughout the orbit raise.
150    traj.to_parquet("./03_geo_raise.parquet", ExportCfg::default())?;
151
152    for status_line in ruggiero_ctrl.status(&final_state) {
153        println!("{status_line}");
154    }
155
156    ruggiero_ctrl
157        .achieved(&final_state)
158        .expect("objective not achieved");
159
160    Ok(())
161}
nyx-core/examples/02_jwst_covar_monte_carlo/main.rs (line 42)
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)?;
101
102    // Finalize setting up the dynamics.
103    let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
104
105    // Build the propagator set up to use for the whole analysis.
106    let setup = Propagator::default(dynamics);
107
108    // All of the analysis will use this duration.
109    let prediction_duration = 6.5 * Unit::Day;
110
111    // === Covariance mapping ===
112    // For the covariance mapping / prediction, we'll use the common orbit determination approach.
113    // This is done by setting up a spacecraft Kalman filter OD process, and predicting for the analysis duration.
114
115    // Build the propagation instance for the OD process.
116    let odp = SpacecraftKalmanOD::new(
117        setup.clone(),
118        KalmanVariant::DeviationTracking,
119        None,
120        BTreeMap::new(),
121        almanac.clone(),
122    );
123
124    // The prediction step is 1 minute by default, configured in the OD process, i.e. how often we want to know the covariance.
125    assert_eq!(odp.max_step, 1_i64.minutes());
126    // Finally, predict, and export the trajectory with covariance to a parquet file.
127    let od_sol = odp.predict_for(jwst_estimate, prediction_duration)?;
128    od_sol.to_parquet("./02_jwst_covar_map.parquet", ExportCfg::default())?;
129
130    // === Monte Carlo framework ===
131    // Nyx comes with a complete multi-threaded Monte Carlo frame. It's blazing fast.
132
133    let my_mc = MonteCarlo::new(
134        jwst, // Nominal state
135        jwst_estimate.to_random_variable()?,
136        "02_jwst".to_string(), // Scenario name
137        None, // No specific seed specified, so one will be drawn from the computer's entropy.
138    );
139
140    let num_runs = 5_000;
141    let rslts = my_mc.run_until_epoch(
142        setup,
143        almanac.clone(),
144        jwst.epoch() + prediction_duration,
145        num_runs,
146    );
147
148    assert_eq!(rslts.runs.len(), num_runs);
149    // Finally, export these results, computing the eclipse percentage for all of these results.
150
151    rslts.to_parquet("02_jwst_monte_carlo.parquet", ExportCfg::default())?;
152
153    Ok(())
154}
nyx-core/examples/03_geo_analysis/drift.rs (line 37)
26fn main() -> Result<(), Box<dyn Error>> {
27    pel::init();
28    // Dynamics models require planetary constants and ephemerides to be defined.
29    // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
30    // This will automatically download the DE440s planetary ephemeris,
31    // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
32    // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
33    // planetary constants kernels.
34    // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
35    // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
36    // references to many functions.
37    let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
38    // Define the orbit epoch
39    let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
40
41    // Define the orbit.
42    // First we need to fetch the Earth J2000 from information from the Almanac.
43    // This allows the frame to include the gravitational parameters and the shape of the Earth,
44    // defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
45    // by loading a different set of planetary constants.
46    let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
47
48    // Placing this GEO bird just above Colorado.
49    // In theory, the eccentricity is zero, but in practice, it's about 1e-5 to 1e-6 at best.
50    let orbit = Orbit::try_keplerian(42164.0, 1e-5, 0., 163.0, 75.0, 0.0, epoch, earth_j2000)?;
51    // Print in in Keplerian form.
52    println!("{orbit:x}");
53
54    let state_bf = almanac.transform_to(orbit, IAU_EARTH_FRAME, None)?;
55    let (orig_lat_deg, orig_long_deg, orig_alt_km) = state_bf.latlongalt()?;
56
57    // Nyx is used for high fidelity propagation, not Keplerian propagation as above.
58    // Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
59    // models such as solar radiation pressure.
60
61    // Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
62    let sc = Spacecraft::builder()
63        .orbit(orbit)
64        .mass(Mass::from_dry_mass(9.60))
65        .srp(SRPData {
66            area_m2: 10e-4,
67            coeff_reflectivity: 1.1,
68        })
69        .build();
70    println!("{sc:x}");
71
72    // Set up the spacecraft dynamics.
73
74    // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
75    // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
76    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
77
78    // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
79    // We're using the JGM3 model here, which is the default in GMAT.
80    let mut jgm3_meta = MetaFile {
81        uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
82        crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
83    };
84    // And let's download it if we don't have it yet.
85    jgm3_meta.process(true)?;
86
87    // Build the spherical harmonics.
88    // The harmonics must be computed in the body fixed frame.
89    // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
90    let harmonics_21x21 = GravityField::new(
91        GravityFieldData::from_cof(
92            &jgm3_meta.uri,
93            21,
94            21,
95            true,
96            almanac.frame_info(IAU_EARTH_FRAME)?,
97        )
98        .unwrap(),
99    );
100
101    // Include the spherical harmonics into the orbital dynamics.
102    orbital_dyn.accel_models.push(harmonics_21x21);
103
104    // We define the solar radiation pressure, using the default solar flux and accounting only
105    // for the eclipsing caused by the Earth and Moon.
106    let srp_dyn = SolarPressure::new(vec![EARTH_J2000, MOON_J2000], &almanac)?;
107
108    // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
109    // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
110    let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
111
112    println!("{dynamics}");
113
114    // Finally, let's propagate this orbit to the same epoch as above.
115    // The first returned value is the spacecraft state at the final epoch.
116    // The second value is the full trajectory where the step size is variable step used by the propagator.
117    let (future_sc, trajectory) = Propagator::default(dynamics)
118        .with(sc, almanac.clone())
119        .until_epoch_with_traj(epoch + Unit::Century * 0.03)?;
120
121    println!("=== High fidelity propagation ===");
122    println!(
123        "SMA changed by {:.3} km",
124        orbit.sma_km()? - future_sc.orbit.sma_km()?
125    );
126    println!(
127        "ECC changed by {:.6}",
128        orbit.ecc()? - future_sc.orbit.ecc()?
129    );
130    println!(
131        "INC changed by {:.3e} deg",
132        orbit.inc_deg()? - future_sc.orbit.inc_deg()?
133    );
134    println!(
135        "RAAN changed by {:.3} deg",
136        orbit.raan_deg()? - future_sc.orbit.raan_deg()?
137    );
138    println!(
139        "AOP changed by {:.3} deg",
140        orbit.aop_deg()? - future_sc.orbit.aop_deg()?
141    );
142    println!(
143        "TA changed by {:.3} deg",
144        orbit.ta_deg()? - future_sc.orbit.ta_deg()?
145    );
146
147    // We also have access to the full trajectory throughout the propagation.
148    println!("{trajectory}");
149
150    println!("Spacecraft params after 3 years without active control:\n{future_sc:x}");
151
152    // With the trajectory, let's build a few data products.
153
154    // 1. Export the trajectory as a parquet file, which includes the Keplerian orbital elements.
155
156    let analysis_step = Unit::Minute * 5;
157
158    trajectory.to_parquet(
159        "./03_geo_hf_prop.parquet",
160        ExportCfg::builder().step(analysis_step).build(),
161    )?;
162
163    // 2. Compute the latitude, longitude, and altitude throughout the trajectory by rotating the spacecraft position into the Earth body fixed frame.
164
165    // We iterate over the trajectory, grabbing a state every two minutes.
166    let mut offset_s = vec![];
167    let mut epoch_str = vec![];
168    let mut longitude_deg = vec![];
169    let mut latitude_deg = vec![];
170    let mut altitude_km = vec![];
171
172    for state in trajectory.every(analysis_step) {
173        // Convert the GEO bird state into the body fixed frame, and keep track of its latitude, longitude, and altitude.
174        // These define the GEO stationkeeping box.
175
176        let this_epoch = state.epoch();
177
178        offset_s.push((this_epoch - orbit.epoch).to_seconds());
179        epoch_str.push(this_epoch.to_isoformat());
180
181        let state_bf = almanac.transform_to(state.orbit, IAU_EARTH_FRAME, None)?;
182        let (lat_deg, long_deg, alt_km) = state_bf.latlongalt()?;
183        longitude_deg.push(long_deg);
184        latitude_deg.push(lat_deg);
185        altitude_km.push(alt_km);
186    }
187
188    println!(
189        "Longitude changed by {:.3} deg -- Box is 0.1 deg E-W",
190        orig_long_deg - longitude_deg.last().unwrap()
191    );
192
193    println!(
194        "Latitude changed by {:.3} deg -- Box is 0.05 deg N-S",
195        orig_lat_deg - latitude_deg.last().unwrap()
196    );
197
198    println!(
199        "Altitude changed by {:.3} km -- Box is 30 km",
200        orig_alt_km - altitude_km.last().unwrap()
201    );
202
203    // Build the station keeping data frame.
204    let mut sk_df = df!(
205        "Offset (s)" => offset_s.clone(),
206        "Epoch (UTC)" => epoch_str.clone(),
207        "Longitude E-W (deg)" => longitude_deg,
208        "Latitude N-S (deg)" => latitude_deg,
209        "Altitude (km)" => altitude_km,
210
211    )?;
212
213    // Create a file to write the Parquet to
214    let file = File::create("./03_geo_lla.parquet").expect("Could not create file");
215
216    // Create a ParquetWriter and write the DataFrame to the file
217    ParquetWriter::new(file).finish(&mut sk_df)?;
218
219    Ok(())
220}
nyx-core/examples/01_orbit_prop/main.rs (line 41)
30fn main() -> Result<(), Box<dyn Error>> {
31    pel::init();
32    // Dynamics models require planetary constants and ephemerides to be defined.
33    // Let's start by grabbing those by using ANISE's latest MetaAlmanac.
34    // This will automatically download the DE440s planetary ephemeris,
35    // the daily-updated Earth Orientation Parameters, the high fidelity Moon orientation
36    // parameters (for the Moon Mean Earth and Moon Principal Axes frames), and the PCK11
37    // planetary constants kernels.
38    // For details, refer to https://github.com/nyx-space/anise/blob/master/data/latest.dhall.
39    // Note that we place the Almanac into an Arc so we can clone it cheaply and provide read-only
40    // references to many functions.
41    let almanac = Arc::new(MetaAlmanac::latest().map_err(Box::new)?);
42    // Define the orbit epoch
43    let epoch = Epoch::from_gregorian_utc_hms(2024, 2, 29, 12, 13, 14);
44
45    // Define the orbit.
46    // First we need to fetch the Earth J2000 from information from the Almanac.
47    // This allows the frame to include the gravitational parameters and the shape of the Earth,
48    // defined as a tri-axial ellipoid. Note that this shape can be changed manually or in the Almanac
49    // by loading a different set of planetary constants.
50    let earth_j2000 = almanac.frame_info(EARTH_J2000)?;
51
52    let orbit =
53        Orbit::try_keplerian_altitude(300.0, 0.015, 68.5, 65.2, 75.0, 0.0, epoch, earth_j2000)?;
54    // Print in in Keplerian form.
55    println!("{orbit:x}");
56
57    // There are two ways to propagate an orbit. We can make a quick approximation assuming only two-body
58    // motion. This is a useful first order approximation but it isn't used in real-world applications.
59
60    // This approach is a feature of ANISE.
61    let future_orbit_tb = orbit.at_epoch(epoch + Unit::Day * 3)?;
62    println!("{future_orbit_tb:x}");
63
64    // Two body propagation relies solely on Kepler's laws, so only the true anomaly will change.
65    println!(
66        "SMA changed by {:.3e} km",
67        orbit.sma_km()? - future_orbit_tb.sma_km()?
68    );
69    println!(
70        "ECC changed by {:.3e}",
71        orbit.ecc()? - future_orbit_tb.ecc()?
72    );
73    println!(
74        "INC changed by {:.3e} deg",
75        orbit.inc_deg()? - future_orbit_tb.inc_deg()?
76    );
77    println!(
78        "RAAN changed by {:.3e} deg",
79        orbit.raan_deg()? - future_orbit_tb.raan_deg()?
80    );
81    println!(
82        "AOP changed by {:.3e} deg",
83        orbit.aop_deg()? - future_orbit_tb.aop_deg()?
84    );
85    println!(
86        "TA changed by {:.3} deg",
87        orbit.ta_deg()? - future_orbit_tb.ta_deg()?
88    );
89
90    // Nyx is used for high fidelity propagation, not Keplerian propagation as above.
91    // Nyx only propagates Spacecraft at the moment, which allows it to account for acceleration
92    // models such as solar radiation pressure.
93
94    // Let's build a cubesat sized spacecraft, with an SRP area of 10 cm^2 and a mass of 9.6 kg.
95    let sc = Spacecraft::builder()
96        .orbit(orbit)
97        .mass(Mass::from_dry_mass(9.60))
98        .srp(SRPData {
99            area_m2: 10e-4,
100            coeff_reflectivity: 1.1,
101        })
102        .build();
103    println!("{sc:x}");
104
105    // Set up the spacecraft dynamics.
106
107    // Specify that the orbital dynamics must account for the graviational pull of the Moon and the Sun.
108    // The gravity of the Earth will also be accounted for since the spaceraft in an Earth orbit.
109    let mut orbital_dyn = OrbitalDynamics::point_masses(vec![MOON, SUN]);
110
111    // We want to include the spherical harmonics, so let's download the gravitational data from the Nyx Cloud.
112    // We're using the JGM3 model here, which is the default in GMAT.
113    let mut jgm3_meta = MetaFile {
114        uri: "http://public-data.nyxspace.com/nyx/models/JGM3.cof.gz".to_string(),
115        crc32: Some(0xF446F027), // Specifying the CRC32 avoids redownloading it if it's cached.
116    };
117    // And let's download it if we don't have it yet.
118    jgm3_meta.process(true)?;
119
120    // Build the spherical harmonics.
121    // The harmonics must be computed in the body fixed frame.
122    // We're using the long term prediction of the Earth centered Earth fixed frame, IAU Earth.
123    let harmonics_21x21 = GravityField::new(
124        GravityFieldData::from_cof(
125            &jgm3_meta.uri,
126            21,
127            21,
128            true,
129            almanac.frame_info(IAU_EARTH_FRAME)?,
130        )
131        .unwrap(),
132    );
133
134    // Include the spherical harmonics into the orbital dynamics.
135    orbital_dyn.accel_models.push(harmonics_21x21);
136
137    // We define the solar radiation pressure, using the default solar flux and accounting only
138    // for the eclipsing caused by the Earth.
139    let srp_dyn = SolarPressure::default_flux(EARTH_J2000, &almanac)?;
140
141    // Finalize setting up the dynamics, specifying the force models (orbital_dyn) separately from the
142    // acceleration models (SRP in this case). Use `from_models` to specify multiple accel models.
143    let dynamics = SpacecraftDynamics::from_model(orbital_dyn, srp_dyn);
144
145    println!("{dynamics}");
146
147    // Finally, let's propagate this orbit to the same epoch as above.
148    // The first returned value is the spacecraft state at the final epoch.
149    // The second value is the full trajectory where the step size is variable step used by the propagator.
150    let (future_sc, trajectory) = Propagator::default(dynamics)
151        .with(sc, almanac.clone())
152        .until_epoch_with_traj(future_orbit_tb.epoch)?;
153
154    println!("=== High fidelity propagation ===");
155    println!(
156        "SMA changed by {:.3} km",
157        orbit.sma_km()? - future_sc.orbit.sma_km()?
158    );
159    println!(
160        "ECC changed by {:.6}",
161        orbit.ecc()? - future_sc.orbit.ecc()?
162    );
163    println!(
164        "INC changed by {:.3e} deg",
165        orbit.inc_deg()? - future_sc.orbit.inc_deg()?
166    );
167    println!(
168        "RAAN changed by {:.3} deg",
169        orbit.raan_deg()? - future_sc.orbit.raan_deg()?
170    );
171    println!(
172        "AOP changed by {:.3} deg",
173        orbit.aop_deg()? - future_sc.orbit.aop_deg()?
174    );
175    println!(
176        "TA changed by {:.3} deg",
177        orbit.ta_deg()? - future_sc.orbit.ta_deg()?
178    );
179
180    // We also have access to the full trajectory throughout the propagation.
181    println!("{trajectory}");
182
183    // With the trajectory, let's build a few data products.
184
185    // 1. Export the trajectory as a CCSDS OEM version 2.0 file and as a parquet file, which includes the Keplerian orbital elements.
186
187    trajectory.to_oem_file(
188        "./01_cubesat_hf_prop.oem",
189        "CUBESAT-ID".to_string(),
190        Some("Nyx Space".to_string()),
191        Some("CUBESAT".to_string()),
192        ExportCfg::builder().step(Unit::Minute * 2).build(),
193    )?;
194
195    trajectory.to_parquet_with_cfg(
196        "./01_cubesat_hf_prop.parquet",
197        ExportCfg::builder().step(Unit::Minute * 2).build(),
198    )?;
199
200    // 2. Compare the difference in the radial-intrack-crosstrack frame between the high fidelity
201    // and Keplerian propagation. The RIC frame is commonly used to compute the difference in position
202    // and velocity of different spacecraft.
203    // 3. Compute the azimuth, elevation, range, and range-rate data of that spacecraft as seen from Boulder, CO, USA.
204
205    let boulder_station = GroundStation::from_point(
206        "Boulder, CO, USA".to_string(),
207        40.014984,   // latitude in degrees
208        -105.270546, // longitude in degrees
209        1.6550,      // altitude in kilometers
210        almanac.frame_info(IAU_EARTH_FRAME)?,
211    );
212
213    // We iterate over the trajectory, grabbing a state every two minutes.
214    let mut offset_s = vec![];
215    let mut epoch_str = vec![];
216    let mut ric_x_km = vec![];
217    let mut ric_y_km = vec![];
218    let mut ric_z_km = vec![];
219    let mut ric_vx_km_s = vec![];
220    let mut ric_vy_km_s = vec![];
221    let mut ric_vz_km_s = vec![];
222
223    let mut azimuth_deg = vec![];
224    let mut elevation_deg = vec![];
225    let mut range_km = vec![];
226    let mut range_rate_km_s = vec![];
227    for state in trajectory.every(Unit::Minute * 2) {
228        // Try to compute the Keplerian/two body state just in time.
229        // This method occasionally fails to converge on an appropriate true anomaly
230        // from the mean anomaly. If that happens, we just skip this state.
231        // The high fidelity and Keplerian states diverge continuously, and we're curious
232        // about the divergence in this quick analysis.
233        let this_epoch = state.epoch();
234        match orbit.at_epoch(this_epoch) {
235            Ok(tb_then) => {
236                offset_s.push((this_epoch - orbit.epoch).to_seconds());
237                epoch_str.push(format!("{this_epoch}"));
238                // Compute the two body state just in time.
239                let ric = state.orbit.ric_difference(&tb_then)?;
240                ric_x_km.push(ric.radius_km.x);
241                ric_y_km.push(ric.radius_km.y);
242                ric_z_km.push(ric.radius_km.z);
243                ric_vx_km_s.push(ric.velocity_km_s.x);
244                ric_vy_km_s.push(ric.velocity_km_s.y);
245                ric_vz_km_s.push(ric.velocity_km_s.z);
246
247                // Compute the AER data for each state.
248                let aer = almanac.azimuth_elevation_range_sez(
249                    state.orbit,
250                    boulder_station.to_orbit(this_epoch, &almanac)?,
251                    None,
252                    None,
253                )?;
254                azimuth_deg.push(aer.azimuth_deg);
255                elevation_deg.push(aer.elevation_deg);
256                range_km.push(aer.range_km);
257                range_rate_km_s.push(aer.range_rate_km_s);
258            }
259            Err(e) => warn!("{} {e}", state.epoch()),
260        };
261    }
262
263    // Build the data frames.
264    let ric_df = df!(
265        "Offset (s)" => offset_s.clone(),
266        "Epoch" => epoch_str.clone(),
267        "RIC X (km)" => ric_x_km,
268        "RIC Y (km)" => ric_y_km,
269        "RIC Z (km)" => ric_z_km,
270        "RIC VX (km/s)" => ric_vx_km_s,
271        "RIC VY (km/s)" => ric_vy_km_s,
272        "RIC VZ (km/s)" => ric_vz_km_s,
273    )?;
274
275    println!("RIC difference at start\n{}", ric_df.head(Some(10)));
276    println!("RIC difference at end\n{}", ric_df.tail(Some(10)));
277
278    let aer_df = df!(
279        "Offset (s)" => offset_s.clone(),
280        "Epoch" => epoch_str.clone(),
281        "azimuth (deg)" => azimuth_deg,
282        "elevation (deg)" => elevation_deg,
283        "range (km)" => range_km,
284        "range rate (km/s)" => range_rate_km_s,
285    )?;
286
287    // Finally, let's see when the spacecraft is visible, assuming 15 degrees minimum elevation.
288    let mask = aer_df
289        .column("elevation (deg)")?
290        .gt(&Column::Scalar(ScalarColumn::new(
291            "elevation mask (deg)".into(),
292            Scalar::new(DataType::Float64, AnyValue::Float64(15.0)),
293            offset_s.len(),
294        )))?;
295    let cubesat_visible = aer_df.filter(&mask)?;
296
297    println!("{cubesat_visible}");
298
299    Ok(())
300}

pub fn from_dhall(repr: &str) -> Result<MetaAlmanac, MetaAlmanacError>

Loads this Meta Almanac from its Dhall string representation

pub fn to_dhall(&self) -> Result<String, MetaAlmanacError>

Serializes the configurated Meta Almanac into a Dhall string

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impl MetaAlmanac

pub fn dumps(&self) -> Result<String, MetaAlmanacError>

Dumps the configured Meta Almanac into a Dhall string. Equivalent to to_dhall().

:rtype: str

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impl MetaAlmanac

pub fn py_new( maybe_path: Option<String>, ) -> Result<MetaAlmanac, MetaAlmanacError>

Loads the provided path as a Dhall file. If no path is provided, creates an empty MetaAlmanac that can store MetaFiles.

pub fn py_process( &mut self, py: Python<'_>, autodelete: Option<bool>, ) -> Result<Almanac, AlmanacError>

Fetch all of the URIs and return a loaded Almanac. When downloading the data, ANISE will create a temporarily lock file to prevent race conditions where multiple processes download the data at the same time. Set autodelete to true to delete this lock file if a dead lock is detected after 10 seconds. Set this flag to false if you have more than ten processes which may attempt to download files in parallel.

:type autodelete: bool, optional :rtype: Almanac

Trait Implementations§

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impl Clone for MetaAlmanac

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fn clone(&self) -> MetaAlmanac

Returns a duplicate of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for MetaAlmanac

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fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter. Read more
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impl Default for MetaAlmanac

By default, the MetaAlmanac will download the DE440s.bsp file, the PCK0008.PCA, the full Moon Principal Axis BPC (moon_pa_de440_200625) and the latest high precision Earth kernel from JPL.

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fn default() -> MetaAlmanac

Returns the “default value” for a type. Read more
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impl DerefToPyAny for MetaAlmanac

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impl<'de> Deserialize<'de> for MetaAlmanac

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fn deserialize<__D>( __deserializer: __D, ) -> Result<MetaAlmanac, <__D as Deserializer<'de>>::Error>
where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more
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impl<'a, 'py> FromPyObject<'a, 'py> for MetaAlmanac

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type Error = PyClassGuardError<'a, 'py>

The type returned in the event of a conversion error. Read more
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fn extract( obj: Borrowed<'a, 'py, PyAny>, ) -> Result<MetaAlmanac, <MetaAlmanac as FromPyObject<'a, 'py>>::Error>

Extracts Self from the bound smart pointer obj. Read more
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impl FromStr for MetaAlmanac

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type Err = MetaAlmanacError

The associated error which can be returned from parsing.
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fn from_str(s: &str) -> Result<MetaAlmanac, <MetaAlmanac as FromStr>::Err>

Parses a string s to return a value of this type. Read more
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impl<'py> IntoPyObject<'py> for MetaAlmanac

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type Target = MetaAlmanac

The Python output type
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type Output = Bound<'py, <MetaAlmanac as IntoPyObject<'py>>::Target>

The smart pointer type to use. Read more
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type Error = PyErr

The type returned in the event of a conversion error.
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fn into_pyobject( self, py: Python<'py>, ) -> Result<<MetaAlmanac as IntoPyObject<'py>>::Output, <MetaAlmanac as IntoPyObject<'py>>::Error>

Performs the conversion.
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impl PartialEq for MetaAlmanac

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fn eq(&self, other: &MetaAlmanac) -> bool

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl PyClass for MetaAlmanac

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const NAME: &'static str = "MetaAlmanac"

Name of the class. Read more
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type Frozen = False

Whether the pyclass is frozen. Read more
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impl PyTypeInfo for MetaAlmanac

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const NAME: &'static str = <Self as ::pyo3::PyClass>::NAME

👎Deprecated since 0.28.0:

prefer using ::type_object(py).name() to get the correct runtime value

Class name.
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const MODULE: Option<&'static str> = <Self as ::pyo3::impl_::pyclass::PyClassImpl>::MODULE

👎Deprecated since 0.28.0:

prefer using ::type_object(py).module() to get the correct runtime value

Module name, if any.
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fn type_object_raw(py: Python<'_>) -> *mut PyTypeObject

Returns the PyTypeObject instance for this type.
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fn type_object(py: Python<'_>) -> Bound<'_, PyType>

Returns the safe abstraction over the type object.
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fn is_type_of(object: &Bound<'_, PyAny>) -> bool

Checks if object is an instance of this type or a subclass of this type.
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fn is_exact_type_of(object: &Bound<'_, PyAny>) -> bool

Checks if object is an instance of this type.
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impl Serialize for MetaAlmanac

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fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>
where __S: Serializer,

Serialize this value into the given Serde serializer. Read more
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impl StaticType for MetaAlmanac
where Vec<MetaFile>: StaticType,

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fn static_type() -> SimpleType

Return the Dhall type that represents this type. Read more
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impl StructuralPartialEq for MetaAlmanac

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Gets the TypeId of self. Read more
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Immutably borrows from an owned value. Read more
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Mutably borrows from an owned value. Read more
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where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. Read more
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impl<T> DeserializeOwned for T
where T: for<'de> Deserialize<'de>,

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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fn from_dhall(v: &Value) -> Result<T, Error>

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impl<'py, T> FromPyObjectOwned<'py> for T
where T: for<'a> FromPyObject<'a, 'py>,

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Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
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Calls U::from(self).

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Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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Converts self into an owned Python object, dropping type information.
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