Examples with NumericalPropagator org.orekit.propagation.numerical.NumericalPropagator used on opensource projects

Example 21 with NumericalPropagator

use of org.orekit.propagation.numerical.NumericalPropagator in project Orekit by CS-SI.

the class JacobianPropagatorConverter method getObjectiveFunction.

/**
 * {@inheritDoc}
 */
protected MultivariateVectorFunction getObjectiveFunction() {
    return new MultivariateVectorFunction() {

        /**
         * {@inheritDoc}
         */
        public double[] value(final double[] arg) throws IllegalArgumentException, OrekitExceptionWrapper {
            try {
                final double[] value = new double[getTargetSize()];
                final NumericalPropagator prop = builder.buildPropagator(arg);
                final int stateSize = isOnlyPosition() ? 3 : 6;
                final List<SpacecraftState> sample = getSample();
                for (int i = 0; i < sample.size(); ++i) {
                    final int row = i * stateSize;
                    if (prop.getInitialState().getDate().equals(sample.get(i).getDate())) {
                        // use initial state
                        fillRows(value, row, prop.getInitialState());
                    } else {
                        // use a date detector to pick up states
                        prop.addEventDetector(new DateDetector(sample.get(i).getDate()).withHandler(new EventHandler<DateDetector>() {

                            /**
                             * {@inheritDoc}
                             */
                            @Override
                            public Action eventOccurred(final SpacecraftState state, final DateDetector detector, final boolean increasing) throws OrekitException {
                                fillRows(value, row, state);
                                return row + stateSize >= getTargetSize() ? Action.STOP : Action.CONTINUE;
                            }
                        }));
                    }
                }
                prop.propagate(sample.get(sample.size() - 1).getDate().shiftedBy(10.0));
                return value;
            } catch (OrekitException ex) {
                throw new OrekitExceptionWrapper(ex);
            }
        }
    };
}

Example 22 with NumericalPropagator

use of org.orekit.propagation.numerical.NumericalPropagator in project Orekit by CS-SI.

the class JacobianPropagatorConverter method getModel.

/**
 * {@inheritDoc}
 */
protected MultivariateJacobianFunction getModel() {
    return new MultivariateJacobianFunction() {

        /**
         * {@inheritDoc}
         */
        public Pair<RealVector, RealMatrix> value(final RealVector point) throws IllegalArgumentException, OrekitExceptionWrapper {
            try {
                final RealVector value = new ArrayRealVector(getTargetSize());
                final RealMatrix jacobian = MatrixUtils.createRealMatrix(getTargetSize(), point.getDimension());
                final NumericalPropagator prop = builder.buildPropagator(point.toArray());
                final int stateSize = isOnlyPosition() ? 3 : 6;
                final ParameterDriversList orbitalParameters = builder.getOrbitalParametersDrivers();
                final PartialDerivativesEquations pde = new PartialDerivativesEquations("pde", prop);
                final ParameterDriversList propagationParameters = pde.getSelectedParameters();
                prop.setInitialState(pde.setInitialJacobians(prop.getInitialState()));
                final JacobiansMapper mapper = pde.getMapper();
                final List<SpacecraftState> sample = getSample();
                for (int i = 0; i < sample.size(); ++i) {
                    final int row = i * stateSize;
                    if (prop.getInitialState().getDate().equals(sample.get(i).getDate())) {
                        // use initial state and Jacobians
                        fillRows(value, jacobian, row, prop.getInitialState(), stateSize, orbitalParameters, propagationParameters, mapper);
                    } else {
                        // use a date detector to pick up state and Jacobians
                        prop.addEventDetector(new DateDetector(sample.get(i).getDate()).withHandler(new EventHandler<DateDetector>() {

                            /**
                             * {@inheritDoc}
                             */
                            @Override
                            public Action eventOccurred(final SpacecraftState state, final DateDetector detector, final boolean increasing) throws OrekitException {
                                fillRows(value, jacobian, row, state, stateSize, orbitalParameters, propagationParameters, mapper);
                                return row + stateSize >= getTargetSize() ? Action.STOP : Action.CONTINUE;
                            }
                        }));
                    }
                }
                prop.propagate(sample.get(sample.size() - 1).getDate().shiftedBy(10.0));
                return new Pair<RealVector, RealMatrix>(value, jacobian);
            } catch (OrekitException ex) {
                throw new OrekitExceptionWrapper(ex);
            }
        }
    };
}

Example 23 with NumericalPropagator

use of org.orekit.propagation.numerical.NumericalPropagator in project Orekit by CS-SI.

the class RelativityTest method testSmallEffectOnOrbit.

/**
 * check against example in Tapley, Schutz, and Born, p 65-66. They predict a
 * progression of perigee of 11 arcsec/year. To get the same results we must set the
 * propagation tolerances to 1e-5.
 *
 * @throws OrekitException on error
 */
@Test
public void testSmallEffectOnOrbit() throws OrekitException {
    // setup
    final double gm = Constants.EIGEN5C_EARTH_MU;
    Orbit orbit = new KeplerianOrbit(7500e3, 0.025, FastMath.toRadians(41.2), 0, 0, 0, PositionAngle.TRUE, frame, date, gm);
    double[][] tol = NumericalPropagator.tolerances(0.00001, orbit, OrbitType.CARTESIAN);
    AbstractIntegrator integrator = new DormandPrince853Integrator(1, 3600, tol[0], tol[1]);
    NumericalPropagator propagator = new NumericalPropagator(integrator);
    propagator.setOrbitType(OrbitType.CARTESIAN);
    propagator.addForceModel(new Relativity(gm));
    propagator.setInitialState(new SpacecraftState(orbit));
    // action: propagate a period
    AbsoluteDate end = orbit.getDate().shiftedBy(30 * Constants.JULIAN_DAY);
    PVCoordinates actual = propagator.getPVCoordinates(end, frame);
    // verify
    KeplerianOrbit endOrbit = new KeplerianOrbit(actual, frame, end, gm);
    KeplerianOrbit startOrbit = new KeplerianOrbit(orbit);
    double dp = endOrbit.getPerigeeArgument() - startOrbit.getPerigeeArgument();
    double dtYears = end.durationFrom(orbit.getDate()) / Constants.JULIAN_YEAR;
    double dpDeg = FastMath.toDegrees(dp);
    // change in argument of perigee in arcseconds per year
    double arcsecPerYear = dpDeg * 3600 / dtYears;
    Assert.assertEquals(11, arcsecPerYear, 0.5);
}

Example 24 with NumericalPropagator

use of org.orekit.propagation.numerical.NumericalPropagator in project Orekit by CS-SI.

the class RelativityTest method RealFieldExpectErrorTest.

/**
 *Same test as the previous one but not adding the ForceModel to the NumericalPropagator
 *        it is a test to validate the previous test.
 *        (to test if the ForceModel it's actually
 *        doing something in the Propagator and the FieldPropagator)
 */
@Test
public void RealFieldExpectErrorTest() throws OrekitException {
    DSFactory factory = new DSFactory(6, 0);
    DerivativeStructure a_0 = factory.variable(0, 7e7);
    DerivativeStructure e_0 = factory.variable(1, 0.4);
    DerivativeStructure i_0 = factory.variable(2, 85 * FastMath.PI / 180);
    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();
    OrbitType type = OrbitType.KEPLERIAN;
    double[][] tolerance = NumericalPropagator.tolerances(0.001, 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);
    final Relativity forceModel = new Relativity(Constants.EIGEN5C_EARTH_MU);
    FNP.addForceModel(forceModel);
    // NOT ADDING THE FORCE MODEL TO THE NUMERICAL PROPAGATOR   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(0, Vector3D.distance(finPVC_DS.toPVCoordinates().getPosition(), finPVC_R.getPosition()), 8.0e-13 * finPVC_R.getPosition().getNorm());
}

Example 25 with NumericalPropagator

use of org.orekit.propagation.numerical.NumericalPropagator in project Orekit by CS-SI.

the class SolidTidesTest method propagate.

private SpacecraftState propagate(Orbit orbit, AbsoluteDate target, ForceModel... forceModels) throws OrekitException {
    double[][] tolerances = NumericalPropagator.tolerances(10, orbit, OrbitType.KEPLERIAN);
    AbstractIntegrator integrator = new DormandPrince853Integrator(1.0e-3, 300, tolerances[0], tolerances[1]);
    NumericalPropagator propagator = new NumericalPropagator(integrator);
    for (ForceModel forceModel : forceModels) {
        propagator.addForceModel(forceModel);
    }
    propagator.setInitialState(new SpacecraftState(orbit));
    return propagator.propagate(target);
}