Examples with ClassicalRungeKuttaIntegrator org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator used on opensource projects

Example 1 with ClassicalRungeKuttaIntegrator

use of org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator in project Orekit by CS-SI.

the class DragForceTest 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, 7e6);
    DerivativeStructure e_0 = factory.variable(1, 0.01);
    DerivativeStructure i_0 = factory.variable(2, 1.2);
    DerivativeStructure R_0 = factory.variable(3, 0.7);
    DerivativeStructure O_0 = factory.variable(4, 0.5);
    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();
    ClassicalRungeKuttaFieldIntegrator<DerivativeStructure> integrator = new ClassicalRungeKuttaFieldIntegrator<>(field, zero.add(6));
    ClassicalRungeKuttaIntegrator RIntegrator = new ClassicalRungeKuttaIntegrator(6);
    OrbitType type = OrbitType.EQUINOCTIAL;
    FieldNumericalPropagator<DerivativeStructure> FNP = new FieldNumericalPropagator<>(field, integrator);
    FNP.setOrbitType(type);
    FNP.setInitialState(initialState);
    NumericalPropagator NP = new NumericalPropagator(RIntegrator);
    NP.setOrbitType(type);
    NP.setInitialState(iSR);
    final DragForce forceModel = new DragForce(new HarrisPriester(CelestialBodyFactory.getSun(), new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true))), new BoxAndSolarArraySpacecraft(1.5, 2.0, 1.8, CelestialBodyFactory.getSun(), 20.0, Vector3D.PLUS_J, 1.2, 0.7, 0.2));
    FNP.addForceModel(forceModel);
    NP.addForceModel(forceModel);
    FieldAbsoluteDate<DerivativeStructure> target = J2000.shiftedBy(1000.);
    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[] { 1e3, 0.005, 0.005, 0.01, 0.01, 0.01 }, 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.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]);
        // System.out.println(pos_DS.getX().getPartialDerivative(1));
        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-5);
        Assert.assertEquals(y_DS, y, FastMath.abs(y - pos_DS.getY().getReal()) * 1e-5);
        Assert.assertEquals(z_DS, z, FastMath.abs(z - pos_DS.getZ().getReal()) * 1e-5);
        // 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-7);
        Assert.assertEquals(vy_DS, vy, FastMath.abs(vy) * 1e-7);
        Assert.assertEquals(vz_DS, vz, FastMath.abs(vz) * 1e-7);
        // 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-5);
        Assert.assertEquals(ay_DS, ay, FastMath.abs(ay) * 1e-5);
        Assert.assertEquals(az_DS, az, FastMath.abs(az) * 1e-5);
    }
}

Example 2 with ClassicalRungeKuttaIntegrator

use of org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator in project Orekit by CS-SI.

the class NumericalPropagatorTest method testNotInitialised2.

@Test(expected = OrekitException.class)
public void testNotInitialised2() throws OrekitException {
    final AbstractIntegratedPropagator notInitialised = new NumericalPropagator(new ClassicalRungeKuttaIntegrator(10.0));
    notInitialised.propagate(AbsoluteDate.J2000_EPOCH, AbsoluteDate.J2000_EPOCH.shiftedBy(3600));
}

Example 3 with ClassicalRungeKuttaIntegrator

use of org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator in project Orekit by CS-SI.

the class NumericalPropagatorTest method testNotInitialised1.

@Test(expected = OrekitException.class)
public void testNotInitialised1() throws OrekitException {
    final AbstractIntegratedPropagator notInitialised = new NumericalPropagator(new ClassicalRungeKuttaIntegrator(10.0));
    notInitialised.propagate(AbsoluteDate.J2000_EPOCH);
}

Example 4 with ClassicalRungeKuttaIntegrator

use of org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator in project Orekit by CS-SI.

the class DSSTPropagatorTest method testPropagationWithSolarRadiationPressure.

@Test
public void testPropagationWithSolarRadiationPressure() throws OrekitException {
    // Central Body geopotential 2x0
    final UnnormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getUnnormalizedProvider(2, 0);
    DSSTForceModel zonal = new DSSTZonal(provider, 2, 1, 5);
    DSSTForceModel tesseral = new DSSTTesseral(CelestialBodyFactory.getEarth().getBodyOrientedFrame(), Constants.WGS84_EARTH_ANGULAR_VELOCITY, provider, 2, 0, 0, 2, 2, 0, 0);
    // SRP Force Model
    DSSTForceModel srp = new DSSTSolarRadiationPressure(1.2, 100., CelestialBodyFactory.getSun(), Constants.WGS84_EARTH_EQUATORIAL_RADIUS);
    // GEO Orbit
    final AbsoluteDate initDate = new AbsoluteDate(2003, 9, 16, 0, 0, 00.000, TimeScalesFactory.getUTC());
    final Orbit orbit = new KeplerianOrbit(42166258., 0.0001, FastMath.toRadians(0.001), FastMath.toRadians(315.4985), FastMath.toRadians(130.7562), FastMath.toRadians(44.2377), PositionAngle.MEAN, FramesFactory.getGCRF(), initDate, provider.getMu());
    // Set propagator with state and force model
    dsstProp = new DSSTPropagator(new ClassicalRungeKuttaIntegrator(86400.));
    dsstProp.setInitialState(new SpacecraftState(orbit), false);
    dsstProp.addForceModel(zonal);
    dsstProp.addForceModel(tesseral);
    dsstProp.addForceModel(srp);
    // 10 days propagation
    final SpacecraftState state = dsstProp.propagate(initDate.shiftedBy(10. * 86400.));
    // Ref Standalone_DSST:
    // a    = 42166257.99807995 m
    // h/ey = -0.1191876027555493D-03
    // k/ex = -0.1781865038201885D-05
    // p/hy =  0.6618387121369373D-05
    // q/hx = -0.5624363171289686D-05
    // lM   = 140°3496229467104
    Assert.assertEquals(42166257.99807995, state.getA(), 0.8);
    Assert.assertEquals(-0.1781865038201885e-05, state.getEquinoctialEx(), 3.e-7);
    Assert.assertEquals(-0.1191876027555493e-03, state.getEquinoctialEy(), 4.e-6);
    Assert.assertEquals(-0.5624363171289686e-05, state.getHx(), 4.e-9);
    Assert.assertEquals(0.6618387121369373e-05, state.getHy(), 3.e-10);
    Assert.assertEquals(140.3496229467104, FastMath.toDegrees(MathUtils.normalizeAngle(state.getLM(), FastMath.PI)), 2.e-4);
}

Example 5 with ClassicalRungeKuttaIntegrator

use of org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator in project Orekit by CS-SI.

the class OrekitStepHandlerTest method testIsInterpolated.

/**
 * Check {@link OrekitStepInterpolator#isPreviousStateInterpolated()} and {@link
 * OrekitStepInterpolator#isCurrentStateInterpolated()}.
 *
 * @throws OrekitException on error.
 */
@Test
public void testIsInterpolated() throws OrekitException {
    // setup
    NumericalPropagator propagator = new NumericalPropagator(new ClassicalRungeKuttaIntegrator(60));
    AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
    Frame eci = FramesFactory.getGCRF();
    SpacecraftState ic = new SpacecraftState(new KeplerianOrbit(6378137 + 500e3, 1e-3, 0, 0, 0, 0, PositionAngle.TRUE, eci, date, Constants.EIGEN5C_EARTH_MU));
    propagator.setInitialState(ic);
    propagator.setOrbitType(OrbitType.CARTESIAN);
    // detector triggers half way through second step
    DateDetector detector = new DateDetector(date.shiftedBy(90)).withHandler(new ContinueOnEvent<>());
    propagator.addEventDetector(detector);
    // action and verify
    Queue<Boolean> expected = new ArrayDeque<>(Arrays.asList(false, false, false, true, true, false));
    propagator.setMasterMode(new OrekitStepHandler() {

        @Override
        public void handleStep(OrekitStepInterpolator interpolator, boolean isLast) {
            assertEquals(expected.poll(), interpolator.isPreviousStateInterpolated());
            assertEquals(expected.poll(), interpolator.isCurrentStateInterpolated());
        }
    });
    final AbsoluteDate end = date.shiftedBy(120);
    assertEquals(end, propagator.propagate(end).getDate());
}