use of org.orekit.utils.PVCoordinates in project Orekit by CS-SI.
the class HolmesFeatherstoneAttractionModelTest method RealFieldTest.
/**
*Testing if the propagation between the FieldPropagation and the propagation
* is equivalent.
* Also testing if propagating X+dX with the propagation is equivalent to
* propagation X with the FieldPropagation and then applying the taylor
* expansion of dX to the result.
*/
@Test
public void RealFieldTest() throws OrekitException {
DSFactory factory = new DSFactory(6, 4);
DerivativeStructure a_0 = factory.variable(0, 7201009.7124401);
DerivativeStructure e_0 = factory.variable(1, 1e-3);
DerivativeStructure i_0 = factory.variable(2, 98.7 * FastMath.PI / 180);
DerivativeStructure R_0 = factory.variable(3, 15.0 * 22.5 * FastMath.PI / 180);
DerivativeStructure O_0 = factory.variable(4, 93.0 * FastMath.PI / 180);
DerivativeStructure n_0 = factory.variable(5, 0.1);
Field<DerivativeStructure> field = a_0.getField();
DerivativeStructure zero = field.getZero();
FieldAbsoluteDate<DerivativeStructure> J2000 = new FieldAbsoluteDate<>(field);
Frame EME = FramesFactory.getEME2000();
FieldKeplerianOrbit<DerivativeStructure> FKO = new FieldKeplerianOrbit<>(a_0, e_0, i_0, R_0, O_0, n_0, PositionAngle.MEAN, EME, J2000, Constants.EIGEN5C_EARTH_MU);
FieldSpacecraftState<DerivativeStructure> initialState = new FieldSpacecraftState<>(FKO);
SpacecraftState iSR = initialState.toSpacecraftState();
OrbitType type = OrbitType.EQUINOCTIAL;
double[][] tolerance = NumericalPropagator.tolerances(10.0, FKO.toOrbit(), type);
AdaptiveStepsizeFieldIntegrator<DerivativeStructure> integrator = new DormandPrince853FieldIntegrator<>(field, 0.001, 200, tolerance[0], tolerance[1]);
integrator.setInitialStepSize(zero.add(60));
AdaptiveStepsizeIntegrator RIntegrator = new DormandPrince853Integrator(0.001, 200, tolerance[0], tolerance[1]);
RIntegrator.setInitialStepSize(60);
FieldNumericalPropagator<DerivativeStructure> FNP = new FieldNumericalPropagator<>(field, integrator);
FNP.setOrbitType(type);
FNP.setInitialState(initialState);
NumericalPropagator NP = new NumericalPropagator(RIntegrator);
NP.setOrbitType(type);
NP.setInitialState(iSR);
double[][] c = new double[3][1];
c[0][0] = 0.0;
c[2][0] = normalizedC20;
double[][] s = new double[3][1];
NormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getNormalizedProvider(6378136.460, mu, TideSystem.UNKNOWN, c, s);
HolmesFeatherstoneAttractionModel forceModel = new HolmesFeatherstoneAttractionModel(itrf, provider);
FNP.addForceModel(forceModel);
NP.addForceModel(forceModel);
FieldAbsoluteDate<DerivativeStructure> target = J2000.shiftedBy(1005.);
FieldSpacecraftState<DerivativeStructure> finalState_DS = FNP.propagate(target);
SpacecraftState finalState_R = NP.propagate(target.toAbsoluteDate());
FieldPVCoordinates<DerivativeStructure> finPVC_DS = finalState_DS.getPVCoordinates();
PVCoordinates finPVC_R = finalState_R.getPVCoordinates();
Assert.assertEquals(finPVC_DS.toPVCoordinates().getPosition().getX(), finPVC_R.getPosition().getX(), FastMath.abs(finPVC_R.getPosition().getX()) * 1e-11);
Assert.assertEquals(finPVC_DS.toPVCoordinates().getPosition().getY(), finPVC_R.getPosition().getY(), FastMath.abs(finPVC_R.getPosition().getY()) * 1e-11);
Assert.assertEquals(finPVC_DS.toPVCoordinates().getPosition().getZ(), finPVC_R.getPosition().getZ(), FastMath.abs(finPVC_R.getPosition().getZ()) * 1e-11);
long number = 23091991;
RandomGenerator RG = new Well19937a(number);
GaussianRandomGenerator NGG = new GaussianRandomGenerator(RG);
UncorrelatedRandomVectorGenerator URVG = new UncorrelatedRandomVectorGenerator(new double[] { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 }, new double[] { 1e1, 0.001, 0.001, 0.001, 0.001, 0.001 }, NGG);
double a_R = a_0.getReal();
double e_R = e_0.getReal();
double i_R = i_0.getReal();
double R_R = R_0.getReal();
double O_R = O_0.getReal();
double n_R = n_0.getReal();
for (int ii = 0; ii < 1; ii++) {
double[] rand_next = URVG.nextVector();
double a_shift = a_R + rand_next[0];
double e_shift = e_R + rand_next[1];
double i_shift = i_R + rand_next[2];
double R_shift = R_R + rand_next[3];
double O_shift = O_R + rand_next[4];
double n_shift = n_R + rand_next[5];
KeplerianOrbit shiftedOrb = new KeplerianOrbit(a_shift, e_shift, i_shift, R_shift, O_shift, n_shift, PositionAngle.MEAN, EME, J2000.toAbsoluteDate(), Constants.EIGEN5C_EARTH_MU);
SpacecraftState shift_iSR = new SpacecraftState(shiftedOrb);
NumericalPropagator shift_NP = new NumericalPropagator(RIntegrator);
shift_NP.setOrbitType(type);
shift_NP.setInitialState(shift_iSR);
shift_NP.addForceModel(forceModel);
SpacecraftState finalState_shift = shift_NP.propagate(target.toAbsoluteDate());
PVCoordinates finPVC_shift = finalState_shift.getPVCoordinates();
// position check
FieldVector3D<DerivativeStructure> pos_DS = finPVC_DS.getPosition();
double x_DS = pos_DS.getX().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double y_DS = pos_DS.getY().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double z_DS = pos_DS.getZ().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double x = finPVC_shift.getPosition().getX();
double y = finPVC_shift.getPosition().getY();
double z = finPVC_shift.getPosition().getZ();
Assert.assertEquals(x_DS, x, FastMath.abs(x - pos_DS.getX().getReal()) * 1e-8);
Assert.assertEquals(y_DS, y, FastMath.abs(y - pos_DS.getY().getReal()) * 1e-8);
Assert.assertEquals(z_DS, z, FastMath.abs(z - pos_DS.getZ().getReal()) * 1e-8);
// velocity check
FieldVector3D<DerivativeStructure> vel_DS = finPVC_DS.getVelocity();
double vx_DS = vel_DS.getX().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double vy_DS = vel_DS.getY().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double vz_DS = vel_DS.getZ().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double vx = finPVC_shift.getVelocity().getX();
double vy = finPVC_shift.getVelocity().getY();
double vz = finPVC_shift.getVelocity().getZ();
Assert.assertEquals(vx_DS, vx, FastMath.abs(vx) * 1e-9);
Assert.assertEquals(vy_DS, vy, FastMath.abs(vy) * 1e-9);
Assert.assertEquals(vz_DS, vz, FastMath.abs(vz) * 1e-9);
// acceleration check
FieldVector3D<DerivativeStructure> acc_DS = finPVC_DS.getAcceleration();
double ax_DS = acc_DS.getX().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double ay_DS = acc_DS.getY().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double az_DS = acc_DS.getZ().taylor(rand_next[0], rand_next[1], rand_next[2], rand_next[3], rand_next[4], rand_next[5]);
double ax = finPVC_shift.getAcceleration().getX();
double ay = finPVC_shift.getAcceleration().getY();
double az = finPVC_shift.getAcceleration().getZ();
Assert.assertEquals(ax_DS, ax, FastMath.abs(ax) * 1e-9);
Assert.assertEquals(ay_DS, ay, FastMath.abs(ay) * 1e-9);
Assert.assertEquals(az_DS, az, FastMath.abs(az) * 1e-9);
}
}
use of org.orekit.utils.PVCoordinates 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);
}
}
use of org.orekit.utils.PVCoordinates 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);
}
use of org.orekit.utils.PVCoordinates 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);
}
use of org.orekit.utils.PVCoordinates 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);
}
}
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