Examples with CartesianOrbit org.orekit.orbits.CartesianOrbit used on opensource projects

Example 36 with CartesianOrbit

use of org.orekit.orbits.CartesianOrbit in project Orekit by CS-SI.

the class OrekitEphemerisFileTest method testWritingToOEM.

@Test
public void testWritingToOEM() throws OrekitException, IOException {
    final double muTolerance = 1e-12;
    final double positionTolerance = 1e-8;
    final double velocityTolerance = 1e-8;
    final String satId = "SATELLITE1";
    final double sma = 10000000;
    final double inc = Math.toRadians(45.0);
    final double ecc = 0.001;
    final double raan = 0.0;
    final double pa = 0.0;
    final double ta = 0.0;
    final AbsoluteDate date = new AbsoluteDate();
    final Frame frame = FramesFactory.getGCRF();
    final CelestialBody body = CelestialBodyFactory.getEarth();
    final double mu = body.getGM();
    KeplerianOrbit initialOrbit = new KeplerianOrbit(sma, ecc, inc, pa, raan, ta, PositionAngle.TRUE, frame, date, mu);
    KeplerianPropagator propagator = new KeplerianPropagator(initialOrbit);
    final double propagationDurationSeconds = 86400.0;
    final double stepSizeSeconds = 60.0;
    List<SpacecraftState> states = new ArrayList<SpacecraftState>();
    for (double dt = 0.0; dt < propagationDurationSeconds; dt += stepSizeSeconds) {
        states.add(propagator.propagate(date.shiftedBy(dt)));
    }
    OrekitEphemerisFile ephemerisFile = new OrekitEphemerisFile();
    OrekitSatelliteEphemeris satellite = ephemerisFile.addSatellite(satId);
    satellite.addNewSegment(states);
    String tempOemFile = Files.createTempFile("OrekitEphemerisFileTest", ".oem").toString();
    new OEMWriter().write(tempOemFile, ephemerisFile);
    EphemerisFile ephemerisFromFile = new OEMParser().parse(tempOemFile);
    Files.delete(Paths.get(tempOemFile));
    EphemerisSegment segment = ephemerisFromFile.getSatellites().get(satId).getSegments().get(0);
    assertEquals(states.get(0).getDate(), segment.getStart());
    assertEquals(states.get(states.size() - 1).getDate(), segment.getStop());
    assertEquals(states.size(), segment.getCoordinates().size());
    assertEquals(frame, segment.getFrame());
    assertEquals(body.getName().toUpperCase(), segment.getFrameCenterString());
    assertEquals(body.getGM(), segment.getMu(), muTolerance);
    for (int i = 0; i < states.size(); i++) {
        TimeStampedPVCoordinates expected = states.get(i).getPVCoordinates();
        TimeStampedPVCoordinates actual = segment.getCoordinates().get(i);
        assertEquals(expected.getDate(), actual.getDate());
        assertEquals(0.0, Vector3D.distance(expected.getPosition(), actual.getPosition()), positionTolerance);
        assertEquals(0.0, Vector3D.distance(expected.getVelocity(), actual.getVelocity()), velocityTolerance);
    }
    // test ingested ephemeris generates access intervals
    final OneAxisEllipsoid parentShape = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    final double latitude = 0.0;
    final double longitude = 0.0;
    final double altitude = 0.0;
    final GeodeticPoint point = new GeodeticPoint(latitude, longitude, altitude);
    final TopocentricFrame topo = new TopocentricFrame(parentShape, point, "testPoint1");
    final ElevationDetector elevationDetector = new ElevationDetector(topo);
    final EphemerisSegmentPropagator ephemerisSegmentPropagator = new EphemerisSegmentPropagator(segment);
    final EventsLogger lookupLogger = new EventsLogger();
    ephemerisSegmentPropagator.addEventDetector(lookupLogger.monitorDetector(elevationDetector));
    final EventsLogger referenceLogger = new EventsLogger();
    propagator.clearEventsDetectors();
    propagator.addEventDetector(referenceLogger.monitorDetector(elevationDetector));
    propagator.propagate(segment.getStart(), segment.getStop());
    ephemerisSegmentPropagator.propagate(segment.getStart(), segment.getStop());
    final double dateEpsilon = 1.0e-9;
    assertTrue(referenceLogger.getLoggedEvents().size() > 0);
    assertEquals(referenceLogger.getLoggedEvents().size(), lookupLogger.getLoggedEvents().size());
    for (int i = 0; i < referenceLogger.getLoggedEvents().size(); i++) {
        LoggedEvent reference = referenceLogger.getLoggedEvents().get(i);
        LoggedEvent actual = lookupLogger.getLoggedEvents().get(i);
        assertEquals(0.0, FastMath.abs(reference.getState().getDate().durationFrom(actual.getState().getDate())), dateEpsilon);
    }
    final Propagator embeddedPropagator = segment.getPropagator();
    final EventsLogger embeddedPropLogger = new EventsLogger();
    embeddedPropagator.addEventDetector(embeddedPropLogger.monitorDetector(elevationDetector));
    embeddedPropagator.propagate(segment.getStart(), segment.getStop());
    assertEquals(referenceLogger.getLoggedEvents().size(), embeddedPropLogger.getLoggedEvents().size());
    for (int i = 0; i < referenceLogger.getLoggedEvents().size(); i++) {
        LoggedEvent reference = referenceLogger.getLoggedEvents().get(i);
        LoggedEvent actual = embeddedPropLogger.getLoggedEvents().get(i);
        assertEquals(0.0, FastMath.abs(reference.getState().getDate().durationFrom(actual.getState().getDate())), dateEpsilon);
    }
    final List<SpacecraftState> readInStates = new ArrayList<SpacecraftState>();
    segment.getCoordinates().forEach(c -> {
        try {
            readInStates.add(new SpacecraftState(new CartesianOrbit(c, frame, mu)));
        } catch (IllegalArgumentException | OrekitException e) {
            fail(e.getLocalizedMessage());
        }
    });
    final int interpolationPoints = 5;
    Ephemeris directEphemProp = new Ephemeris(readInStates, interpolationPoints);
    final EventsLogger directEphemPropLogger = new EventsLogger();
    directEphemProp.addEventDetector(directEphemPropLogger.monitorDetector(elevationDetector));
    directEphemProp.propagate(segment.getStart(), segment.getStop());
    assertEquals(referenceLogger.getLoggedEvents().size(), directEphemPropLogger.getLoggedEvents().size());
    for (int i = 0; i < referenceLogger.getLoggedEvents().size(); i++) {
        LoggedEvent reference = referenceLogger.getLoggedEvents().get(i);
        LoggedEvent actual = directEphemPropLogger.getLoggedEvents().get(i);
        assertEquals(0.0, FastMath.abs(reference.getState().getDate().durationFrom(actual.getState().getDate())), dateEpsilon);
    }
}

Example 37 with CartesianOrbit

use of org.orekit.orbits.CartesianOrbit in project Orekit by CS-SI.

the class RelativityTest method testJacobianVs80Implementation.

@Test
public void testJacobianVs80Implementation() throws OrekitException {
    double gm = Constants.EIGEN5C_EARTH_MU;
    Relativity relativity = new Relativity(gm);
    final Vector3D p = new Vector3D(3777828.75000531, -5543949.549783845, 2563117.448578311);
    final Vector3D v = new Vector3D(489.0060271721, -2849.9328929417, -6866.4671013153);
    SpacecraftState s = new SpacecraftState(new CartesianOrbit(new PVCoordinates(p, v), frame, date, gm));
    checkStateJacobianVs80Implementation(s, relativity, new LofOffset(s.getFrame(), LOFType.VVLH), 1.0e-50, false);
}

Example 38 with CartesianOrbit

use of org.orekit.orbits.CartesianOrbit in project Orekit by CS-SI.

the class RelativityTest method testAcceleration.

/**
 * check the acceleration from relativity
 *
 * @throws OrekitException on error
 */
@Test
public void testAcceleration() throws OrekitException {
    double gm = Constants.EIGEN5C_EARTH_MU;
    Relativity relativity = new Relativity(gm);
    Assert.assertFalse(relativity.dependsOnPositionOnly());
    final Vector3D p = new Vector3D(3777828.75000531, -5543949.549783845, 2563117.448578311);
    final Vector3D v = new Vector3D(489.0060271721, -2849.9328929417, -6866.4671013153);
    SpacecraftState s = new SpacecraftState(new CartesianOrbit(new PVCoordinates(p, v), frame, date, gm));
    // action
    Vector3D acceleration = relativity.acceleration(s, relativity.getParameters());
    // verify
    // force is ~1e-8 so this give ~3 sig figs.
    double tol = 2e-11;
    Vector3D circularApproximation = p.normalize().scalarMultiply(gm / p.getNormSq() * 3 * v.getNormSq() / (c * c));
    Assert.assertEquals(0, acceleration.subtract(circularApproximation).getNorm(), tol);
    // check derivatives
    FieldSpacecraftState<DerivativeStructure> sDS = toDS(s, new LofOffset(s.getFrame(), LOFType.VVLH));
    final Vector3D actualDerivatives = relativity.acceleration(sDS, relativity.getParameters(sDS.getDate().getField())).toVector3D();
    Assert.assertEquals(0, actualDerivatives.subtract(circularApproximation).getNorm(), tol);
}

Example 39 with CartesianOrbit

use of org.orekit.orbits.CartesianOrbit in project Orekit by CS-SI.

the class OnBoardAntennaInterSatellitesRangeModifierTest method testEffect.

@Test
public void testEffect() throws OrekitException {
    Context context = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
    final NumericalPropagatorBuilder propagatorBuilder = context.createBuilder(OrbitType.KEPLERIAN, PositionAngle.TRUE, true, 1.0e-6, 60.0, 0.001);
    propagatorBuilder.setAttitudeProvider(new LofOffset(propagatorBuilder.getFrame(), LOFType.LVLH));
    // create perfect inter-satellites range measurements without antenna offset
    final TimeStampedPVCoordinates original = context.initialOrbit.getPVCoordinates();
    final Orbit closeOrbit = new CartesianOrbit(new TimeStampedPVCoordinates(context.initialOrbit.getDate(), original.getPosition().add(new Vector3D(1000, 2000, 3000)), original.getVelocity().add(new Vector3D(-0.03, 0.01, 0.02))), context.initialOrbit.getFrame(), context.initialOrbit.getMu());
    final Propagator closePropagator = EstimationTestUtils.createPropagator(closeOrbit, propagatorBuilder);
    closePropagator.setEphemerisMode();
    closePropagator.propagate(context.initialOrbit.getDate().shiftedBy(3.5 * closeOrbit.getKeplerianPeriod()));
    final BoundedPropagator ephemeris = closePropagator.getGeneratedEphemeris();
    final Propagator p1 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> spacecraftCenteredMeasurements = EstimationTestUtils.createMeasurements(p1, new InterSatellitesRangeMeasurementCreator(ephemeris, Vector3D.ZERO, Vector3D.ZERO), 1.0, 3.0, 300.0);
    // create perfect inter-satellites range measurements with antenna offset
    final Vector3D apc1 = new Vector3D(-2.5, 0.0, 0);
    final Vector3D apc2 = new Vector3D(0.0, 0.8, 0);
    final Propagator p2 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> antennaCenteredMeasurements = EstimationTestUtils.createMeasurements(p2, new InterSatellitesRangeMeasurementCreator(ephemeris, apc1, apc2), 1.0, 3.0, 300.0);
    final Propagator p3 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    OnBoardAntennaInterSatellitesRangeModifier modifier = new OnBoardAntennaInterSatellitesRangeModifier(apc1, apc2);
    for (int i = 0; i < spacecraftCenteredMeasurements.size(); ++i) {
        InterSatellitesRange sr = (InterSatellitesRange) spacecraftCenteredMeasurements.get(i);
        sr.addModifier(modifier);
        EstimatedMeasurement<InterSatellitesRange> estimated = sr.estimate(0, 0, new SpacecraftState[] { p3.propagate(sr.getDate()), ephemeris.propagate(sr.getDate()) });
        InterSatellitesRange ar = (InterSatellitesRange) antennaCenteredMeasurements.get(i);
        Assert.assertEquals(0.0, sr.getDate().durationFrom(ar.getDate()), 2.0e-8);
        Assert.assertEquals(ar.getObservedValue()[0], estimated.getEstimatedValue()[0], 2.0e-5);
    }
}

Example 40 with CartesianOrbit

use of org.orekit.orbits.CartesianOrbit in project Orekit by CS-SI.

the class NumericalPropagatorTest method testEventDetectionBug.

@Test
public void testEventDetectionBug() throws OrekitException, IOException, ParseException {
    TimeScale utc = TimeScalesFactory.getUTC();
    AbsoluteDate initialDate = new AbsoluteDate(2005, 1, 1, 0, 0, 0.0, utc);
    double duration = 100000.;
    AbsoluteDate endDate = new AbsoluteDate(initialDate, duration);
    // Initialization of the frame EME2000
    Frame EME2000 = FramesFactory.getEME2000();
    // Initial orbit
    double a = 35786000. + 6378137.0;
    double e = 0.70;
    double rApogee = a * (1 + e);
    double vApogee = FastMath.sqrt(mu * (1 - e) / (a * (1 + e)));
    Orbit geo = new CartesianOrbit(new PVCoordinates(new Vector3D(rApogee, 0., 0.), new Vector3D(0., vApogee, 0.)), EME2000, initialDate, mu);
    duration = geo.getKeplerianPeriod();
    endDate = new AbsoluteDate(initialDate, duration);
    // Numerical Integration
    final double minStep = 0.001;
    final double maxStep = 1000;
    final double initStep = 60;
    final double[] absTolerance = { 0.001, 1.0e-9, 1.0e-9, 1.0e-6, 1.0e-6, 1.0e-6, 0.001 };
    final double[] relTolerance = { 1.0e-7, 1.0e-4, 1.0e-4, 1.0e-7, 1.0e-7, 1.0e-7, 1.0e-7 };
    AdaptiveStepsizeIntegrator integrator = new DormandPrince853Integrator(minStep, maxStep, absTolerance, relTolerance);
    integrator.setInitialStepSize(initStep);
    // Numerical propagator based on the integrator
    propagator = new NumericalPropagator(integrator);
    double mass = 1000.;
    SpacecraftState initialState = new SpacecraftState(geo, mass);
    propagator.setInitialState(initialState);
    propagator.setOrbitType(OrbitType.CARTESIAN);
    // Set the events Detectors
    ApsideDetector event1 = new ApsideDetector(geo);
    propagator.addEventDetector(event1);
    // Set the propagation mode
    propagator.setSlaveMode();
    // Propagate
    SpacecraftState finalState = propagator.propagate(endDate);
    // we should stop long before endDate
    Assert.assertTrue(endDate.durationFrom(finalState.getDate()) > 40000.0);
}