Examples with LofOffset org.orekit.attitudes.LofOffset used on opensource projects

Example 1 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class HarmonicParametricAccelerationTest method testEquivalentTangentialOverriddenManeuver.

@Test
public void testEquivalentTangentialOverriddenManeuver() throws OrekitException {
    final double mass = 2500;
    final double isp = Double.POSITIVE_INFINITY;
    final double duration = 4000;
    final double f = 400;
    final AttitudeProvider maneuverLaw = new LofOffset(initialOrbit.getFrame(), LOFType.VNC);
    ConstantThrustManeuver maneuver = new ConstantThrustManeuver(initialOrbit.getDate().shiftedBy(-10.0), duration, f, isp, Vector3D.PLUS_I);
    final AttitudeProvider accelerationLaw = new CelestialBodyPointed(initialOrbit.getFrame(), CelestialBodyFactory.getSun(), Vector3D.PLUS_K, Vector3D.PLUS_I, Vector3D.PLUS_K);
    final HarmonicParametricAcceleration lofAcceleration = new HarmonicParametricAcceleration(Vector3D.PLUS_I, maneuverLaw, "prefix", null, Double.POSITIVE_INFINITY, 1);
    lofAcceleration.getParametersDrivers()[0].setValue(f / mass);
    lofAcceleration.getParametersDrivers()[1].setValue(0.5 * FastMath.PI);
    doTestEquivalentManeuver(mass, maneuverLaw, maneuver, accelerationLaw, lofAcceleration, 1.0e-15);
}

Example 2 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class HarmonicParametricAccelerationTest method testEquivalentTangentialManeuverField.

@Test
public void testEquivalentTangentialManeuverField() throws OrekitException {
    final double mass = 2500;
    final double isp = Double.POSITIVE_INFINITY;
    final double duration = 4000;
    final double f = 400;
    final AttitudeProvider commonLaw = new LofOffset(initialOrbit.getFrame(), LOFType.VNC);
    ConstantThrustManeuver maneuver = new ConstantThrustManeuver(initialOrbit.getDate().shiftedBy(-10.0), duration, f, isp, Vector3D.PLUS_I);
    final HarmonicParametricAcceleration lofAcceleration = new HarmonicParametricAcceleration(Vector3D.PLUS_I, false, "", null, Double.POSITIVE_INFINITY, 1);
    lofAcceleration.getParametersDrivers()[0].setValue(f / mass);
    lofAcceleration.getParametersDrivers()[1].setValue(0.5 * FastMath.PI);
    doTestEquivalentManeuver(Decimal64Field.getInstance(), mass, commonLaw, maneuver, commonLaw, lofAcceleration, 1.0e-15);
}

Example 3 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class HarmonicParametricAccelerationTest method testCoefficientsDetermination.

@Test
public void testCoefficientsDetermination() throws OrekitException {
    final double mass = 2500;
    final Orbit orbit = new CircularOrbit(7500000.0, 1.0e-4, 1.0e-3, 1.7, 0.3, 0.5, PositionAngle.TRUE, FramesFactory.getEME2000(), new AbsoluteDate(new DateComponents(2004, 2, 3), TimeComponents.H00, TimeScalesFactory.getUTC()), Constants.EIGEN5C_EARTH_MU);
    final double period = orbit.getKeplerianPeriod();
    AttitudeProvider maneuverLaw = new LofOffset(orbit.getFrame(), LOFType.VNC);
    SpacecraftState initialState = new SpacecraftState(orbit, maneuverLaw.getAttitude(orbit, orbit.getDate(), orbit.getFrame()), mass);
    double dP = 10.0;
    double minStep = 0.001;
    double maxStep = 100;
    double[][] tolerance = NumericalPropagator.tolerances(dP, orbit, orbit.getType());
    // generate PV measurements corresponding to a tangential maneuver
    AdaptiveStepsizeIntegrator integrator0 = new DormandPrince853Integrator(minStep, maxStep, tolerance[0], tolerance[1]);
    integrator0.setInitialStepSize(60);
    final NumericalPropagator propagator0 = new NumericalPropagator(integrator0);
    propagator0.setInitialState(initialState);
    propagator0.setAttitudeProvider(maneuverLaw);
    ForceModel hpaRefX1 = new HarmonicParametricAcceleration(Vector3D.PLUS_I, true, "refX1", null, period, 1);
    ForceModel hpaRefY1 = new HarmonicParametricAcceleration(Vector3D.PLUS_J, true, "refY1", null, period, 1);
    ForceModel hpaRefZ2 = new HarmonicParametricAcceleration(Vector3D.PLUS_K, true, "refZ2", null, period, 2);
    hpaRefX1.getParametersDrivers()[0].setValue(2.4e-2);
    hpaRefX1.getParametersDrivers()[1].setValue(3.1);
    hpaRefY1.getParametersDrivers()[0].setValue(4.0e-2);
    hpaRefY1.getParametersDrivers()[1].setValue(0.3);
    hpaRefZ2.getParametersDrivers()[0].setValue(1.0e-2);
    hpaRefZ2.getParametersDrivers()[1].setValue(1.8);
    propagator0.addForceModel(hpaRefX1);
    propagator0.addForceModel(hpaRefY1);
    propagator0.addForceModel(hpaRefZ2);
    final List<ObservedMeasurement<?>> measurements = new ArrayList<>();
    propagator0.setMasterMode(10.0, (state, isLast) -> measurements.add(new PV(state.getDate(), state.getPVCoordinates().getPosition(), state.getPVCoordinates().getVelocity(), 1.0e-3, 1.0e-6, 1.0)));
    propagator0.propagate(orbit.getDate().shiftedBy(900));
    // set up an estimator to retrieve the maneuver as several harmonic accelerations in inertial frame
    final NumericalPropagatorBuilder propagatorBuilder = new NumericalPropagatorBuilder(orbit, new DormandPrince853IntegratorBuilder(minStep, maxStep, dP), PositionAngle.TRUE, dP);
    propagatorBuilder.addForceModel(new HarmonicParametricAcceleration(Vector3D.PLUS_I, true, "X1", null, period, 1));
    propagatorBuilder.addForceModel(new HarmonicParametricAcceleration(Vector3D.PLUS_J, true, "Y1", null, period, 1));
    propagatorBuilder.addForceModel(new HarmonicParametricAcceleration(Vector3D.PLUS_K, true, "Z2", null, period, 2));
    final BatchLSEstimator estimator = new BatchLSEstimator(new LevenbergMarquardtOptimizer(), propagatorBuilder);
    estimator.setParametersConvergenceThreshold(1.0e-2);
    estimator.setMaxIterations(20);
    estimator.setMaxEvaluations(100);
    for (final ObservedMeasurement<?> measurement : measurements) {
        estimator.addMeasurement(measurement);
    }
    // we will estimate only the force model parameters, not the orbit
    for (final ParameterDriver d : estimator.getOrbitalParametersDrivers(false).getDrivers()) {
        d.setSelected(false);
    }
    setParameter(estimator, "X1 γ", 1.0e-2);
    setParameter(estimator, "X1 φ", 4.0);
    setParameter(estimator, "Y1 γ", 1.0e-2);
    setParameter(estimator, "Y1 φ", 0.0);
    setParameter(estimator, "Z2 γ", 1.0e-2);
    setParameter(estimator, "Z2 φ", 1.0);
    estimator.estimate();
    Assert.assertTrue(estimator.getIterationsCount() < 15);
    Assert.assertTrue(estimator.getEvaluationsCount() < 15);
    Assert.assertEquals(0.0, estimator.getOptimum().getRMS(), 1.0e-5);
    Assert.assertEquals(hpaRefX1.getParametersDrivers()[0].getValue(), getParameter(estimator, "X1 γ"), 1.e-12);
    Assert.assertEquals(hpaRefX1.getParametersDrivers()[1].getValue(), getParameter(estimator, "X1 φ"), 1.e-12);
    Assert.assertEquals(hpaRefY1.getParametersDrivers()[0].getValue(), getParameter(estimator, "Y1 γ"), 1.e-12);
    Assert.assertEquals(hpaRefY1.getParametersDrivers()[1].getValue(), getParameter(estimator, "Y1 φ"), 1.e-12);
    Assert.assertEquals(hpaRefZ2.getParametersDrivers()[0].getValue(), getParameter(estimator, "Z2 γ"), 1.e-12);
    Assert.assertEquals(hpaRefZ2.getParametersDrivers()[1].getValue(), getParameter(estimator, "Z2 φ"), 1.e-12);
}

Example 4 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class PolynomialParametricAccelerationTest method testEquivalentTangentialOverriddenManeuver.

@Test
public void testEquivalentTangentialOverriddenManeuver() throws OrekitException {
    final double mass = 2500;
    final double isp = Double.POSITIVE_INFINITY;
    final double duration = 4000;
    final double f = 400;
    final AttitudeProvider maneuverLaw = new LofOffset(initialOrbit.getFrame(), LOFType.VNC);
    ConstantThrustManeuver maneuver = new ConstantThrustManeuver(initialOrbit.getDate().shiftedBy(-10.0), duration, f, isp, Vector3D.PLUS_I);
    final AttitudeProvider accelerationLaw = new CelestialBodyPointed(initialOrbit.getFrame(), CelestialBodyFactory.getSun(), Vector3D.PLUS_K, Vector3D.PLUS_I, Vector3D.PLUS_K);
    final PolynomialParametricAcceleration lofAcceleration = new PolynomialParametricAcceleration(Vector3D.PLUS_I, maneuverLaw, "prefix", null, 0);
    lofAcceleration.getParametersDrivers()[0].setValue(f / mass);
    doTestEquivalentManeuver(mass, maneuverLaw, maneuver, accelerationLaw, lofAcceleration, 1.0e-15);
}

Example 5 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class PolynomialParametricAccelerationTest method testEquivalentTangentialManeuverField.

@Test
public void testEquivalentTangentialManeuverField() throws OrekitException {
    final double mass = 2500;
    final double isp = Double.POSITIVE_INFINITY;
    final double duration = 4000;
    final double f = 400;
    final AttitudeProvider commonLaw = new LofOffset(initialOrbit.getFrame(), LOFType.VNC);
    ConstantThrustManeuver maneuver = new ConstantThrustManeuver(initialOrbit.getDate().shiftedBy(-10.0), duration, f, isp, Vector3D.PLUS_I);
    final PolynomialParametricAcceleration lofAcceleration = new PolynomialParametricAcceleration(Vector3D.PLUS_I, false, "", null, 0);
    lofAcceleration.getParametersDrivers()[0].setValue(f / mass);
    doTestEquivalentManeuver(Decimal64Field.getInstance(), mass, commonLaw, maneuver, commonLaw, lofAcceleration, 1.0e-15);
}