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Example 1 with CartesianOrbit

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

the class OnBoardAntennaInterSatellitesRangeModifierTest method testPreliminary.

@Test
public void testPreliminary() throws OrekitException {
    // this test does not check OnBoardAntennaInterSatellitesRangeModifier at all,
    // it just checks InterSatellitesRangeMeasurementCreator behaves as necessary for the other test
    // the *real* test is testEffect below
    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 double xOffset1 = -2.5;
    final double yOffset2 = 0.8;
    final Propagator p2 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> antennaCenteredMeasurements = EstimationTestUtils.createMeasurements(p2, new InterSatellitesRangeMeasurementCreator(ephemeris, new Vector3D(xOffset1, 0, 0), new Vector3D(0, yOffset2, 0)), 1.0, 3.0, 300.0);
    for (int i = 0; i < spacecraftCenteredMeasurements.size(); ++i) {
        InterSatellitesRange sr = (InterSatellitesRange) spacecraftCenteredMeasurements.get(i);
        InterSatellitesRange ar = (InterSatellitesRange) antennaCenteredMeasurements.get(i);
        Assert.assertEquals(0.0, sr.getDate().durationFrom(ar.getDate()), 2.0e-8);
        Assert.assertTrue(ar.getObservedValue()[0] - sr.getObservedValue()[0] >= -1.0);
        Assert.assertTrue(ar.getObservedValue()[0] - sr.getObservedValue()[0] <= -0.36);
    }
}
Also used : Context(org.orekit.estimation.Context) CartesianOrbit(org.orekit.orbits.CartesianOrbit) CartesianOrbit(org.orekit.orbits.CartesianOrbit) Orbit(org.orekit.orbits.Orbit) TimeStampedPVCoordinates(org.orekit.utils.TimeStampedPVCoordinates) InterSatellitesRange(org.orekit.estimation.measurements.InterSatellitesRange) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) BoundedPropagator(org.orekit.propagation.BoundedPropagator) Propagator(org.orekit.propagation.Propagator) InterSatellitesRangeMeasurementCreator(org.orekit.estimation.measurements.InterSatellitesRangeMeasurementCreator) LofOffset(org.orekit.attitudes.LofOffset) BoundedPropagator(org.orekit.propagation.BoundedPropagator) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) Test(org.junit.Test)

Example 2 with CartesianOrbit

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

the class HolmesFeatherstoneAttractionModelTest method testIssue97.

@Test
@Deprecated
public void testIssue97() throws OrekitException {
    Utils.setDataRoot("regular-data:potential/grgs-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    // pos-vel (from a ZOOM ephemeris reference)
    final Vector3D pos = new Vector3D(6.46885878304673824e+06, -1.88050918456274318e+06, -1.32931592294715829e+04);
    final Vector3D vel = new Vector3D(2.14718074509906819e+03, 7.38239351251748485e+03, -1.14097953925384523e+01);
    final SpacecraftState state = new SpacecraftState(new CartesianOrbit(new PVCoordinates(pos, vel), FramesFactory.getGCRF(), new AbsoluteDate(2005, 3, 5, 0, 24, 0.0, TimeScalesFactory.getTAI()), GravityFieldFactory.getUnnormalizedProvider(1, 1).getMu()));
    for (int i = 2; i <= 69; i++) {
        final ForceModel holmesFeatherstoneModel = new HolmesFeatherstoneAttractionModel(FramesFactory.getITRF(IERSConventions.IERS_2010, true), GravityFieldFactory.getNormalizedProvider(i, i));
        final ForceModel cunninghamModel = new CunninghamAttractionModel(FramesFactory.getITRF(IERSConventions.IERS_2010, true), GravityFieldFactory.getUnnormalizedProvider(i, i));
        double relativeError = accelerationRelativeError(holmesFeatherstoneModel, cunninghamModel, state);
        Assert.assertEquals(0.0, relativeError, 8.0e-15);
    }
}
Also used : SpacecraftState(org.orekit.propagation.SpacecraftState) FieldSpacecraftState(org.orekit.propagation.FieldSpacecraftState) CartesianOrbit(org.orekit.orbits.CartesianOrbit) ForceModel(org.orekit.forces.ForceModel) AbstractForceModel(org.orekit.forces.AbstractForceModel) FieldVector3D(org.hipparchus.geometry.euclidean.threed.FieldVector3D) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) PVCoordinates(org.orekit.utils.PVCoordinates) FieldPVCoordinates(org.orekit.utils.FieldPVCoordinates) FieldAbsoluteDate(org.orekit.time.FieldAbsoluteDate) AbsoluteDate(org.orekit.time.AbsoluteDate) GRGSFormatReader(org.orekit.forces.gravity.potential.GRGSFormatReader) AbstractLegacyForceModelTest(org.orekit.forces.AbstractLegacyForceModelTest) Test(org.junit.Test)

Example 3 with CartesianOrbit

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

the class HolmesFeatherstoneAttractionModelTest method testTimeDependentField.

@Test
public void testTimeDependentField() throws OrekitException {
    Utils.setDataRoot("regular-data:potential/icgem-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new ICGEMFormatReader("eigen-6s-truncated", true));
    final Vector3D pos = new Vector3D(6.46885878304673824e+06, -1.88050918456274318e+06, -1.32931592294715829e+04);
    final Vector3D vel = new Vector3D(2.14718074509906819e+03, 7.38239351251748485e+03, -1.14097953925384523e+01);
    final SpacecraftState spacecraftState = new SpacecraftState(new CartesianOrbit(new PVCoordinates(pos, vel), FramesFactory.getGCRF(), new AbsoluteDate(2005, 3, 5, 0, 24, 0.0, TimeScalesFactory.getTAI()), GravityFieldFactory.getUnnormalizedProvider(1, 1).getMu()));
    double dP = 0.1;
    double duration = 3 * Constants.JULIAN_DAY;
    BoundedPropagator fixedFieldEphemeris = createEphemeris(dP, spacecraftState, duration, GravityFieldFactory.getConstantNormalizedProvider(8, 8));
    BoundedPropagator varyingFieldEphemeris = createEphemeris(dP, spacecraftState, duration, GravityFieldFactory.getNormalizedProvider(8, 8));
    double step = 60.0;
    double maxDeltaT = 0;
    double maxDeltaN = 0;
    double maxDeltaW = 0;
    for (AbsoluteDate date = fixedFieldEphemeris.getMinDate(); date.compareTo(fixedFieldEphemeris.getMaxDate()) < 0; date = date.shiftedBy(step)) {
        PVCoordinates pvFixedField = fixedFieldEphemeris.getPVCoordinates(date, FramesFactory.getGCRF());
        PVCoordinates pvVaryingField = varyingFieldEphemeris.getPVCoordinates(date, FramesFactory.getGCRF());
        Vector3D t = pvFixedField.getVelocity().normalize();
        Vector3D w = pvFixedField.getMomentum().normalize();
        Vector3D n = Vector3D.crossProduct(w, t);
        Vector3D delta = pvVaryingField.getPosition().subtract(pvFixedField.getPosition());
        maxDeltaT = FastMath.max(maxDeltaT, FastMath.abs(Vector3D.dotProduct(delta, t)));
        maxDeltaN = FastMath.max(maxDeltaN, FastMath.abs(Vector3D.dotProduct(delta, n)));
        maxDeltaW = FastMath.max(maxDeltaW, FastMath.abs(Vector3D.dotProduct(delta, w)));
    }
    Assert.assertTrue(maxDeltaT > 0.15);
    Assert.assertTrue(maxDeltaT < 0.25);
    Assert.assertTrue(maxDeltaN > 0.01);
    Assert.assertTrue(maxDeltaN < 0.02);
    Assert.assertTrue(maxDeltaW > 0.05);
    Assert.assertTrue(maxDeltaW < 0.10);
}
Also used : SpacecraftState(org.orekit.propagation.SpacecraftState) FieldSpacecraftState(org.orekit.propagation.FieldSpacecraftState) CartesianOrbit(org.orekit.orbits.CartesianOrbit) ICGEMFormatReader(org.orekit.forces.gravity.potential.ICGEMFormatReader) FieldVector3D(org.hipparchus.geometry.euclidean.threed.FieldVector3D) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) PVCoordinates(org.orekit.utils.PVCoordinates) FieldPVCoordinates(org.orekit.utils.FieldPVCoordinates) BoundedPropagator(org.orekit.propagation.BoundedPropagator) FieldAbsoluteDate(org.orekit.time.FieldAbsoluteDate) AbsoluteDate(org.orekit.time.AbsoluteDate) AbstractLegacyForceModelTest(org.orekit.forces.AbstractLegacyForceModelTest) Test(org.junit.Test)

Example 4 with CartesianOrbit

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

the class HolmesFeatherstoneAttractionModelTest method testParameterDerivative.

@Test
public void testParameterDerivative() throws OrekitException {
    Utils.setDataRoot("regular-data:potential/grgs-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    // pos-vel (from a ZOOM ephemeris reference)
    final Vector3D pos = new Vector3D(6.46885878304673824e+06, -1.88050918456274318e+06, -1.32931592294715829e+04);
    final Vector3D vel = new Vector3D(2.14718074509906819e+03, 7.38239351251748485e+03, -1.14097953925384523e+01);
    final SpacecraftState state = new SpacecraftState(new CartesianOrbit(new PVCoordinates(pos, vel), FramesFactory.getGCRF(), new AbsoluteDate(2005, 3, 5, 0, 24, 0.0, TimeScalesFactory.getTAI()), GravityFieldFactory.getUnnormalizedProvider(1, 1).getMu()));
    final HolmesFeatherstoneAttractionModel holmesFeatherstoneModel = new HolmesFeatherstoneAttractionModel(FramesFactory.getITRF(IERSConventions.IERS_2010, true), GravityFieldFactory.getNormalizedProvider(20, 20));
    final String name = NewtonianAttraction.CENTRAL_ATTRACTION_COEFFICIENT;
    checkParameterDerivative(state, holmesFeatherstoneModel, name, 1.0e-5, 5.0e-12);
}
Also used : SpacecraftState(org.orekit.propagation.SpacecraftState) FieldSpacecraftState(org.orekit.propagation.FieldSpacecraftState) CartesianOrbit(org.orekit.orbits.CartesianOrbit) FieldVector3D(org.hipparchus.geometry.euclidean.threed.FieldVector3D) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) PVCoordinates(org.orekit.utils.PVCoordinates) FieldPVCoordinates(org.orekit.utils.FieldPVCoordinates) FieldAbsoluteDate(org.orekit.time.FieldAbsoluteDate) AbsoluteDate(org.orekit.time.AbsoluteDate) GRGSFormatReader(org.orekit.forces.gravity.potential.GRGSFormatReader) AbstractLegacyForceModelTest(org.orekit.forces.AbstractLegacyForceModelTest) Test(org.junit.Test)

Example 5 with CartesianOrbit

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

the class OrbitDeterminationTest method createOrbit.

/**
 * Create an orbit from input parameters
 * @param parser input file parser
 * @param mu     central attraction coefficient
 * @throws NoSuchElementException if input parameters are missing
 * @throws OrekitException if inertial frame cannot be created
 */
private Orbit createOrbit(final KeyValueFileParser<ParameterKey> parser, final double mu) throws NoSuchElementException, OrekitException {
    final Frame frame;
    if (!parser.containsKey(ParameterKey.INERTIAL_FRAME)) {
        frame = FramesFactory.getEME2000();
    } else {
        frame = parser.getInertialFrame(ParameterKey.INERTIAL_FRAME);
    }
    // Orbit definition
    PositionAngle angleType = PositionAngle.MEAN;
    if (parser.containsKey(ParameterKey.ORBIT_ANGLE_TYPE)) {
        angleType = PositionAngle.valueOf(parser.getString(ParameterKey.ORBIT_ANGLE_TYPE).toUpperCase());
    }
    if (parser.containsKey(ParameterKey.ORBIT_KEPLERIAN_A)) {
        return new KeplerianOrbit(parser.getDouble(ParameterKey.ORBIT_KEPLERIAN_A), parser.getDouble(ParameterKey.ORBIT_KEPLERIAN_E), parser.getAngle(ParameterKey.ORBIT_KEPLERIAN_I), parser.getAngle(ParameterKey.ORBIT_KEPLERIAN_PA), parser.getAngle(ParameterKey.ORBIT_KEPLERIAN_RAAN), parser.getAngle(ParameterKey.ORBIT_KEPLERIAN_ANOMALY), angleType, frame, parser.getDate(ParameterKey.ORBIT_DATE, TimeScalesFactory.getUTC()), mu);
    } else if (parser.containsKey(ParameterKey.ORBIT_EQUINOCTIAL_A)) {
        return new EquinoctialOrbit(parser.getDouble(ParameterKey.ORBIT_EQUINOCTIAL_A), parser.getDouble(ParameterKey.ORBIT_EQUINOCTIAL_EX), parser.getDouble(ParameterKey.ORBIT_EQUINOCTIAL_EY), parser.getDouble(ParameterKey.ORBIT_EQUINOCTIAL_HX), parser.getDouble(ParameterKey.ORBIT_EQUINOCTIAL_HY), parser.getAngle(ParameterKey.ORBIT_EQUINOCTIAL_LAMBDA), angleType, frame, parser.getDate(ParameterKey.ORBIT_DATE, TimeScalesFactory.getUTC()), mu);
    } else if (parser.containsKey(ParameterKey.ORBIT_CIRCULAR_A)) {
        return new CircularOrbit(parser.getDouble(ParameterKey.ORBIT_CIRCULAR_A), parser.getDouble(ParameterKey.ORBIT_CIRCULAR_EX), parser.getDouble(ParameterKey.ORBIT_CIRCULAR_EY), parser.getAngle(ParameterKey.ORBIT_CIRCULAR_I), parser.getAngle(ParameterKey.ORBIT_CIRCULAR_RAAN), parser.getAngle(ParameterKey.ORBIT_CIRCULAR_ALPHA), angleType, frame, parser.getDate(ParameterKey.ORBIT_DATE, TimeScalesFactory.getUTC()), mu);
    } else if (parser.containsKey(ParameterKey.ORBIT_TLE_LINE_1)) {
        final String line1 = parser.getString(ParameterKey.ORBIT_TLE_LINE_1);
        final String line2 = parser.getString(ParameterKey.ORBIT_TLE_LINE_2);
        final TLE tle = new TLE(line1, line2);
        TLEPropagator propagator = TLEPropagator.selectExtrapolator(tle);
        // propagator.setEphemerisMode();
        AbsoluteDate initDate = tle.getDate();
        SpacecraftState initialState = propagator.getInitialState();
        // Transformation from TEME to frame.
        Transform t = FramesFactory.getTEME().getTransformTo(FramesFactory.getEME2000(), initDate.getDate());
        return new CartesianOrbit(t.transformPVCoordinates(initialState.getPVCoordinates()), frame, initDate, mu);
    } else {
        final double[] pos = { parser.getDouble(ParameterKey.ORBIT_CARTESIAN_PX), parser.getDouble(ParameterKey.ORBIT_CARTESIAN_PY), parser.getDouble(ParameterKey.ORBIT_CARTESIAN_PZ) };
        final double[] vel = { parser.getDouble(ParameterKey.ORBIT_CARTESIAN_VX), parser.getDouble(ParameterKey.ORBIT_CARTESIAN_VY), parser.getDouble(ParameterKey.ORBIT_CARTESIAN_VZ) };
        return new CartesianOrbit(new PVCoordinates(new Vector3D(pos), new Vector3D(vel)), frame, parser.getDate(ParameterKey.ORBIT_DATE, TimeScalesFactory.getUTC()), mu);
    }
}
Also used : Frame(org.orekit.frames.Frame) TopocentricFrame(org.orekit.frames.TopocentricFrame) CartesianOrbit(org.orekit.orbits.CartesianOrbit) PositionAngle(org.orekit.orbits.PositionAngle) PVCoordinates(org.orekit.utils.PVCoordinates) TimeStampedPVCoordinates(org.orekit.utils.TimeStampedPVCoordinates) TLEPropagator(org.orekit.propagation.analytical.tle.TLEPropagator) TLE(org.orekit.propagation.analytical.tle.TLE) AbsoluteDate(org.orekit.time.AbsoluteDate) SpacecraftState(org.orekit.propagation.SpacecraftState) CircularOrbit(org.orekit.orbits.CircularOrbit) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) EquinoctialOrbit(org.orekit.orbits.EquinoctialOrbit) KeplerianOrbit(org.orekit.orbits.KeplerianOrbit) Transform(org.orekit.frames.Transform)

Aggregations

CartesianOrbit (org.orekit.orbits.CartesianOrbit)57 Vector3D (org.hipparchus.geometry.euclidean.threed.Vector3D)48 AbsoluteDate (org.orekit.time.AbsoluteDate)43 SpacecraftState (org.orekit.propagation.SpacecraftState)38 Test (org.junit.Test)37 PVCoordinates (org.orekit.utils.PVCoordinates)32 TimeStampedPVCoordinates (org.orekit.utils.TimeStampedPVCoordinates)28 FieldVector3D (org.hipparchus.geometry.euclidean.threed.FieldVector3D)25 FieldSpacecraftState (org.orekit.propagation.FieldSpacecraftState)22 KeplerianOrbit (org.orekit.orbits.KeplerianOrbit)20 Orbit (org.orekit.orbits.Orbit)20 Frame (org.orekit.frames.Frame)17 FieldAbsoluteDate (org.orekit.time.FieldAbsoluteDate)15 OrekitException (org.orekit.errors.OrekitException)14 AbstractLegacyForceModelTest (org.orekit.forces.AbstractLegacyForceModelTest)14 FieldPVCoordinates (org.orekit.utils.FieldPVCoordinates)13 BoundedPropagator (org.orekit.propagation.BoundedPropagator)11 Propagator (org.orekit.propagation.Propagator)10 TimeScale (org.orekit.time.TimeScale)10 DormandPrince853Integrator (org.hipparchus.ode.nonstiff.DormandPrince853Integrator)9