use of org.orekit.orbits.Orbit 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);
}
}
use of org.orekit.orbits.Orbit in project Orekit by CS-SI.
the class HolmesFeatherstoneAttractionModelTest method testStateJacobianVs80Implementation.
@Test
public void testStateJacobianVs80Implementation() 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);
checkStateJacobianVs80Implementation(state, hfModel, new LofOffset(state.getFrame(), LOFType.VVLH), 2.0e-15, false);
}
use of org.orekit.orbits.Orbit in project Orekit by CS-SI.
the class HolmesFeatherstoneAttractionModelTest method testEcksteinHechlerReference.
// test the difference with the analytical extrapolator Eckstein Hechler
@Test
public void testEcksteinHechlerReference() throws OrekitException {
// Definition of initial conditions with position and velocity
AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(584.);
Vector3D position = new Vector3D(3220103., 69623., 6449822.);
Vector3D velocity = new Vector3D(6414.7, -2006., -3180.);
Transform itrfToEME2000 = itrf.getTransformTo(FramesFactory.getEME2000(), date);
Vector3D pole = itrfToEME2000.transformVector(Vector3D.PLUS_K);
Frame poleAligned = new Frame(FramesFactory.getEME2000(), new Transform(date, new Rotation(pole, Vector3D.PLUS_K)), "pole aligned", true);
Orbit initialOrbit = new EquinoctialOrbit(new PVCoordinates(position, velocity), poleAligned, date, mu);
propagator.addForceModel(new HolmesFeatherstoneAttractionModel(itrf, GravityFieldFactory.getNormalizedProvider(ae, mu, TideSystem.UNKNOWN, new double[][] { { 0.0 }, { 0.0 }, { normalizedC20 }, { normalizedC30 }, { normalizedC40 }, { normalizedC50 }, { normalizedC60 } }, new double[][] { { 0.0 }, { 0.0 }, { 0.0 }, { 0.0 }, { 0.0 }, { 0.0 }, { 0.0 } })));
// let the step handler perform the test
propagator.setInitialState(new SpacecraftState(initialOrbit));
propagator.setMasterMode(20, new EckStepHandler(initialOrbit, ae, unnormalizedC20, unnormalizedC30, unnormalizedC40, unnormalizedC50, unnormalizedC60));
propagator.propagate(date.shiftedBy(50000));
Assert.assertTrue(propagator.getCalls() < 1100);
}
use of org.orekit.orbits.Orbit in project Orekit by CS-SI.
the class HolmesFeatherstoneAttractionModelTest method testHelioSynchronous.
// rough test to determine if J2 alone creates heliosynchronism
@Test
public void testHelioSynchronous() throws OrekitException {
// initialization
AbsoluteDate date = new AbsoluteDate(new DateComponents(1970, 07, 01), new TimeComponents(13, 59, 27.816), TimeScalesFactory.getUTC());
Transform itrfToEME2000 = itrf.getTransformTo(FramesFactory.getEME2000(), date);
Vector3D pole = itrfToEME2000.transformVector(Vector3D.PLUS_K);
Frame poleAligned = new Frame(FramesFactory.getEME2000(), new Transform(date, new Rotation(pole, Vector3D.PLUS_K)), "pole aligned", true);
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, poleAligned, date, mu);
double[][] c = new double[3][1];
c[0][0] = 0.0;
c[2][0] = normalizedC20;
double[][] s = new double[3][1];
propagator.addForceModel(new HolmesFeatherstoneAttractionModel(itrf, GravityFieldFactory.getNormalizedProvider(6378136.460, mu, TideSystem.UNKNOWN, c, s)));
// let the step handler perform the test
propagator.setMasterMode(Constants.JULIAN_DAY, new SpotStepHandler(date, mu));
propagator.setInitialState(new SpacecraftState(orbit));
propagator.propagate(date.shiftedBy(7 * Constants.JULIAN_DAY));
Assert.assertTrue(propagator.getCalls() < 9200);
}
use of org.orekit.orbits.Orbit in project Orekit by CS-SI.
the class HolmesFeatherstoneAttractionModelTest method testStateJacobian.
@Test
public void testStateJacobian() 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);
OrbitType integrationType = OrbitType.CARTESIAN;
double[][] tolerances = NumericalPropagator.tolerances(0.01, orbit, integrationType);
propagator = new NumericalPropagator(new DormandPrince853Integrator(1.0e-3, 120, tolerances[0], tolerances[1]));
propagator.setOrbitType(integrationType);
HolmesFeatherstoneAttractionModel hfModel = new HolmesFeatherstoneAttractionModel(itrf, GravityFieldFactory.getNormalizedProvider(50, 50));
Assert.assertEquals(TideSystem.UNKNOWN, hfModel.getTideSystem());
propagator.addForceModel(hfModel);
SpacecraftState state0 = new SpacecraftState(orbit);
propagator.setInitialState(state0);
checkStateJacobian(propagator, state0, date.shiftedBy(3.5 * 3600.0), 50000, tolerances[0], 7.8e-6);
}
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