Examples with GRGSFormatReader org.orekit.forces.gravity.potential.GRGSFormatReader used on opensource projects

Example 6 with GRGSFormatReader

use of org.orekit.forces.gravity.potential.GRGSFormatReader in project Orekit by CS-SI.

the class EstimationTestUtils method geoStationnaryContext.

public static Context geoStationnaryContext(final String dataRoot) throws OrekitException {
    Utils.setDataRoot(dataRoot);
    Context context = new Context();
    context.conventions = IERSConventions.IERS_2010;
    context.utc = TimeScalesFactory.getUTC();
    context.ut1 = TimeScalesFactory.getUT1(context.conventions, true);
    context.displacements = new StationDisplacement[0];
    String Myframename = "MyEarthFrame";
    final AbsoluteDate datedef = new AbsoluteDate(2000, 1, 1, 12, 0, 0.0, context.utc);
    final double omega = Constants.WGS84_EARTH_ANGULAR_VELOCITY;
    final Vector3D rotationRate = new Vector3D(0.0, 0.0, omega);
    TransformProvider MyEarthFrame = new TransformProvider() {

        private static final long serialVersionUID = 1L;

        public Transform getTransform(final AbsoluteDate date) {
            final double rotationduration = date.durationFrom(datedef);
            final Vector3D alpharot = new Vector3D(rotationduration, rotationRate);
            final Rotation rotation = new Rotation(Vector3D.PLUS_K, -alpharot.getZ(), RotationConvention.VECTOR_OPERATOR);
            return new Transform(date, rotation, rotationRate);
        }

        public <T extends RealFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
            final T rotationduration = date.durationFrom(datedef);
            final FieldVector3D<T> alpharot = new FieldVector3D<>(rotationduration, rotationRate);
            final FieldRotation<T> rotation = new FieldRotation<>(FieldVector3D.getPlusK(date.getField()), alpharot.getZ().negate(), RotationConvention.VECTOR_OPERATOR);
            return new FieldTransform<>(date, rotation, new FieldVector3D<>(date.getField(), rotationRate));
        }
    };
    Frame FrameTest = new Frame(FramesFactory.getEME2000(), MyEarthFrame, Myframename, true);
    // Earth is spherical, rotating in one sidereal day
    context.earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, 0.0, FrameTest);
    context.sun = CelestialBodyFactory.getSun();
    context.moon = CelestialBodyFactory.getMoon();
    context.radiationSensitive = new IsotropicRadiationClassicalConvention(2.0, 0.2, 0.8);
    context.dragSensitive = new IsotropicDrag(2.0, 1.2);
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    AstronomicalAmplitudeReader aaReader = new AstronomicalAmplitudeReader("hf-fes2004.dat", 5, 2, 3, 1.0);
    DataProvidersManager.getInstance().feed(aaReader.getSupportedNames(), aaReader);
    Map<Integer, Double> map = aaReader.getAstronomicalAmplitudesMap();
    GravityFieldFactory.addOceanTidesReader(new FESCHatEpsilonReader("fes2004-7x7.dat", 0.01, FastMath.toRadians(1.0), OceanLoadDeformationCoefficients.IERS_2010, map));
    context.gravity = GravityFieldFactory.getNormalizedProvider(20, 20);
    // semimajor axis for a geostationnary satellite
    double da = FastMath.cbrt(context.gravity.getMu() / (omega * omega));
    // context.stations = Arrays.asList(context.createStation(  0.0,  0.0, 0.0, "Lat0_Long0"),
    // context.createStation( 62.29639,   -7.01250,  880.0, "Slættaratindur")
    // );
    context.stations = Arrays.asList(context.createStation(0.0, 0.0, 0.0, "Lat0_Long0"));
    // Station position & velocity in EME2000
    final Vector3D geovelocity = new Vector3D(0., 0., 0.);
    // Compute the frames transformation from station frame to EME2000
    Transform topoToEME = context.stations.get(0).getBaseFrame().getTransformTo(FramesFactory.getEME2000(), new AbsoluteDate(2000, 1, 1, 12, 0, 0.0, context.utc));
    // Station position in EME2000 at reference date
    Vector3D stationPositionEME = topoToEME.transformPosition(Vector3D.ZERO);
    // Satellite position and velocity in Station Frame
    final Vector3D sat_pos = new Vector3D(0., 0., da - stationPositionEME.getNorm());
    final Vector3D acceleration = new Vector3D(-context.gravity.getMu(), sat_pos);
    final PVCoordinates pv_sat_topo = new PVCoordinates(sat_pos, geovelocity, acceleration);
    // satellite position in EME2000
    final PVCoordinates pv_sat_iner = topoToEME.transformPVCoordinates(pv_sat_topo);
    // Geo-stationary Satellite Orbit, tightly above the station (l0-L0)
    context.initialOrbit = new KeplerianOrbit(pv_sat_iner, FramesFactory.getEME2000(), new AbsoluteDate(2000, 1, 1, 12, 0, 0.0, context.utc), context.gravity.getMu());
    context.stations = Arrays.asList(context.createStation(10.0, 45.0, 0.0, "Lat10_Long45"));
    // Turn-around range stations
    // Map entry = master station
    // Map value = slave station associated
    context.TARstations = new HashMap<GroundStation, GroundStation>();
    context.TARstations.put(context.createStation(41.977, 13.600, 671.354, "Fucino"), context.createStation(43.604, 1.444, 263.0, "Toulouse"));
    context.TARstations.put(context.createStation(49.867, 8.65, 144.0, "Darmstadt"), context.createStation(-25.885, 27.707, 1566.633, "Pretoria"));
    return context;
}

Example 7 with GRGSFormatReader

use of org.orekit.forces.gravity.potential.GRGSFormatReader in project Orekit by CS-SI.

the class EstimationTestUtils method eccentricContext.

public static Context eccentricContext(final String dataRoot) throws OrekitException {
    Utils.setDataRoot(dataRoot);
    Context context = new Context();
    context.conventions = IERSConventions.IERS_2010;
    context.earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(context.conventions, true));
    context.sun = CelestialBodyFactory.getSun();
    context.moon = CelestialBodyFactory.getMoon();
    context.radiationSensitive = new IsotropicRadiationClassicalConvention(2.0, 0.2, 0.8);
    context.dragSensitive = new IsotropicDrag(2.0, 1.2);
    final EOPHistory eopHistory = FramesFactory.getEOPHistory(context.conventions, true);
    context.utc = TimeScalesFactory.getUTC();
    context.ut1 = TimeScalesFactory.getUT1(eopHistory);
    context.displacements = new StationDisplacement[] { new TidalDisplacement(Constants.EIGEN5C_EARTH_EQUATORIAL_RADIUS, Constants.JPL_SSD_SUN_EARTH_PLUS_MOON_MASS_RATIO, Constants.JPL_SSD_EARTH_MOON_MASS_RATIO, context.sun, context.moon, context.conventions, false) };
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    AstronomicalAmplitudeReader aaReader = new AstronomicalAmplitudeReader("hf-fes2004.dat", 5, 2, 3, 1.0);
    DataProvidersManager.getInstance().feed(aaReader.getSupportedNames(), aaReader);
    Map<Integer, Double> map = aaReader.getAstronomicalAmplitudesMap();
    GravityFieldFactory.addOceanTidesReader(new FESCHatEpsilonReader("fes2004-7x7.dat", 0.01, FastMath.toRadians(1.0), OceanLoadDeformationCoefficients.IERS_2010, map));
    context.gravity = GravityFieldFactory.getNormalizedProvider(20, 20);
    context.initialOrbit = new KeplerianOrbit(15000000.0, 0.125, 1.25, 0.250, 1.375, 0.0625, PositionAngle.TRUE, FramesFactory.getEME2000(), new AbsoluteDate(2000, 2, 24, 11, 35, 47.0, context.utc), context.gravity.getMu());
    context.stations = // context.createStation(-18.59146, -173.98363,   76.0, "Leimatu`a"),
    Arrays.asList(context.createStation(-53.05388, -75.01551, 1750.0, "Isla Desolación"), context.createStation(62.29639, -7.01250, 880.0, "Slættaratindur"));
    // Turn-around range stations
    // Map entry = master station
    // Map value = slave station associated
    context.TARstations = new HashMap<GroundStation, GroundStation>();
    context.TARstations.put(context.createStation(-53.05388, -75.01551, 1750.0, "Isla Desolación"), context.createStation(-54.815833, -68.317778, 6.0, "Ushuaïa"));
    context.TARstations.put(context.createStation(62.29639, -7.01250, 880.0, "Slættaratindur"), context.createStation(61.405833, -6.705278, 470.0, "Sumba"));
    return context;
}

Example 8 with GRGSFormatReader

use of org.orekit.forces.gravity.potential.GRGSFormatReader in project Orekit by CS-SI.

the class NumericalPropagatorTest method testParallelismIssue258.

@Test
public void testParallelismIssue258() throws OrekitException, InterruptedException, ExecutionException, FileNotFoundException {
    Utils.setDataRoot("regular-data:atmosphere:potential/grgs-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    final double mu = GravityFieldFactory.getNormalizedProvider(2, 2).getMu();
    // Geostationary transfer orbit
    // semi major axis in meters
    final double a = 24396159;
    // eccentricity
    final double e = 0.72831215;
    // inclination
    final double i = FastMath.toRadians(7);
    // perigee argument
    final double omega = FastMath.toRadians(180);
    // right ascension of ascending node
    final double raan = FastMath.toRadians(261);
    // mean anomaly
    final double lM = 0;
    final Frame inertialFrame = FramesFactory.getEME2000();
    final TimeScale utc = TimeScalesFactory.getUTC();
    final AbsoluteDate initialDate = new AbsoluteDate(2003, 1, 1, 00, 00, 00.000, utc);
    final Orbit initialOrbit = new CartesianOrbit(new KeplerianOrbit(a, e, i, omega, raan, lM, PositionAngle.MEAN, inertialFrame, initialDate, mu));
    final SpacecraftState initialState = new SpacecraftState(initialOrbit, 1000);
    // initialize the testing points
    final List<SpacecraftState> states = new ArrayList<SpacecraftState>();
    final NumericalPropagator propagator = createPropagator(initialState, OrbitType.CARTESIAN, PositionAngle.TRUE);
    final double samplingStep = 10000.0;
    propagator.setMasterMode(samplingStep, (state, isLast) -> states.add(state));
    propagator.propagate(initialDate.shiftedBy(5 * samplingStep));
    // compute reference errors, using serial computation in a for loop
    final double[][] referenceErrors = new double[states.size() - 1][];
    for (int startIndex = 0; startIndex < states.size() - 1; ++startIndex) {
        referenceErrors[startIndex] = recomputeFollowing(startIndex, states);
    }
    final Consumer<SpacecraftState> checker = point -> {
        try {
            final int startIndex = states.indexOf(point);
            double[] errors = recomputeFollowing(startIndex, states);
            for (int k = 0; k < errors.length; ++k) {
                Assert.assertEquals(startIndex + " to " + (startIndex + k + 1), referenceErrors[startIndex][k], errors[k], 1.0e-9);
            }
        } catch (OrekitException oe) {
            Assert.fail(oe.getLocalizedMessage());
        }
    };
    // serial propagation using Stream
    states.stream().forEach(checker);
    // parallel propagation using parallelStream
    states.parallelStream().forEach(checker);
}

Example 9 with GRGSFormatReader

use of org.orekit.forces.gravity.potential.GRGSFormatReader in project Orekit by CS-SI.

the class NumericalPropagatorTest method doTestShift.

private static void doTestShift(final CartesianOrbit orbit, final OrbitType orbitType, final PositionAngle angleType, final boolean withDerivatives, final double error60s, final double error120s, final double error300s, final double error600s, final double error900s) throws OrekitException {
    Utils.setDataRoot("regular-data:atmosphere:potential/grgs-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    final NumericalPropagator np = createPropagator(new SpacecraftState(orbit), orbitType, angleType);
    // the reference date for shifts is set at 60s, so the propagator can provide derivatives if needed
    // (derivatives are not available in the initial orbit)
    final AbsoluteDate reference = orbit.getDate().shiftedBy(60.0);
    final ShiftChecker checker = new ShiftChecker(withDerivatives, orbitType, angleType, error60s, error120s, error300s, error600s, error900s);
    np.addEventDetector(new DateDetector(30.0, 1.0e-9, reference, reference.shiftedBy(60.0), reference.shiftedBy(120.0), reference.shiftedBy(300.0), reference.shiftedBy(600.0), reference.shiftedBy(900.0)).withHandler(checker));
    np.propagate(reference.shiftedBy(1000.0));
}

Example 10 with GRGSFormatReader

use of org.orekit.forces.gravity.potential.GRGSFormatReader in project Orekit by CS-SI.

the class HolmesFeatherstoneAttractionModelTest method testStateJacobianVsFiniteDifferences.

@Test
public void testStateJacobianVsFiniteDifferences() throws OrekitException {
    Utils.setDataRoot("regular-data:potential/grgs-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    // initialization
    AbsoluteDate date = new AbsoluteDate(new DateComponents(2000, 07, 01), new TimeComponents(13, 59, 27.816), TimeScalesFactory.getUTC());
    double i = FastMath.toRadians(98.7);
    double omega = FastMath.toRadians(93.0);
    double OMEGA = FastMath.toRadians(15.0 * 22.5);
    Orbit orbit = new KeplerianOrbit(7201009.7124401, 1e-3, i, omega, OMEGA, 0, PositionAngle.MEAN, FramesFactory.getEME2000(), date, mu);
    HolmesFeatherstoneAttractionModel hfModel = new HolmesFeatherstoneAttractionModel(itrf, GravityFieldFactory.getNormalizedProvider(50, 50));
    Assert.assertEquals(TideSystem.UNKNOWN, hfModel.getTideSystem());
    SpacecraftState state = new SpacecraftState(orbit);
    checkStateJacobianVsFiniteDifferences(state, hfModel, Propagator.DEFAULT_LAW, 10.0, 2.0e-10, false);
}