Examples with ThirdBodyAttraction org.orekit.forces.gravity.ThirdBodyAttraction used on opensource projects

Example 1 with ThirdBodyAttraction

use of org.orekit.forces.gravity.ThirdBodyAttraction in project Orekit by CS-SI.

the class FieldNumericalPropagatorTest method createPropagator.

private static <T extends RealFieldElement<T>> FieldNumericalPropagator<T> createPropagator(FieldSpacecraftState<T> spacecraftState, OrbitType orbitType, PositionAngle angleType) throws OrekitException {
    final Field<T> field = spacecraftState.getDate().getField();
    final T zero = field.getZero();
    final double minStep = 0.001;
    final double maxStep = 120.0;
    final T positionTolerance = zero.add(0.1);
    final int degree = 20;
    final int order = 20;
    final double spacecraftArea = 1.0;
    final double spacecraftDragCoefficient = 2.0;
    final double spacecraftReflectionCoefficient = 2.0;
    // propagator main configuration
    final double[][] tol = FieldNumericalPropagator.tolerances(positionTolerance, spacecraftState.getOrbit(), orbitType);
    final FieldODEIntegrator<T> integrator = new DormandPrince853FieldIntegrator<>(field, minStep, maxStep, tol[0], tol[1]);
    final FieldNumericalPropagator<T> np = new FieldNumericalPropagator<>(field, integrator);
    np.setOrbitType(orbitType);
    np.setPositionAngleType(angleType);
    np.setInitialState(spacecraftState);
    // Earth gravity field
    final OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    final NormalizedSphericalHarmonicsProvider harmonicsGravityProvider = GravityFieldFactory.getNormalizedProvider(degree, order);
    np.addForceModel(new HolmesFeatherstoneAttractionModel(earth.getBodyFrame(), harmonicsGravityProvider));
    // Sun and Moon attraction
    np.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getSun()));
    np.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getMoon()));
    // atmospheric drag
    MarshallSolarActivityFutureEstimation msafe = new MarshallSolarActivityFutureEstimation("Jan2000F10-edited-data\\.txt", MarshallSolarActivityFutureEstimation.StrengthLevel.AVERAGE);
    DataProvidersManager.getInstance().feed(msafe.getSupportedNames(), msafe);
    DTM2000 atmosphere = new DTM2000(msafe, CelestialBodyFactory.getSun(), earth);
    np.addForceModel(new DragForce(atmosphere, new IsotropicDrag(spacecraftArea, spacecraftDragCoefficient)));
    // solar radiation pressure
    np.addForceModel(new SolarRadiationPressure(CelestialBodyFactory.getSun(), earth.getEquatorialRadius(), new IsotropicRadiationSingleCoefficient(spacecraftArea, spacecraftReflectionCoefficient)));
    return np;
}

Example 2 with ThirdBodyAttraction

use of org.orekit.forces.gravity.ThirdBodyAttraction in project Orekit by CS-SI.

the class PartialDerivativesTest method testWrongParametersDimension.

@Test
public void testWrongParametersDimension() throws OrekitException {
    Orbit initialOrbit = new KeplerianOrbit(8000000.0, 0.01, 0.1, 0.7, 0, 1.2, PositionAngle.TRUE, FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH, Constants.EIGEN5C_EARTH_MU);
    double dP = 0.001;
    ForceModel sunAttraction = new ThirdBodyAttraction(CelestialBodyFactory.getSun());
    sunAttraction.getParameterDriver("Sun attraction coefficient").setSelected(true);
    ForceModel moonAttraction = new ThirdBodyAttraction(CelestialBodyFactory.getMoon());
    NumericalPropagator propagator = setUpPropagator(initialOrbit, dP, OrbitType.EQUINOCTIAL, PositionAngle.TRUE, sunAttraction, moonAttraction);
    PartialDerivativesEquations partials = new PartialDerivativesEquations("partials", propagator);
    try {
        partials.setInitialJacobians(new SpacecraftState(initialOrbit), new double[6][6], new double[6][3]);
        partials.computeDerivatives(new SpacecraftState(initialOrbit), new double[6]);
        Assert.fail("an exception should have been thrown");
    } catch (OrekitException oe) {
        Assert.assertEquals(OrekitMessages.INITIAL_MATRIX_AND_PARAMETERS_NUMBER_MISMATCH, oe.getSpecifier());
    }
}

Example 3 with ThirdBodyAttraction

use of org.orekit.forces.gravity.ThirdBodyAttraction in project Orekit by CS-SI.

the class SecularAndHarmonicTest method createPropagator.

private NumericalPropagator createPropagator(CircularOrbit orbit) throws OrekitException {
    OrbitType type = OrbitType.CIRCULAR;
    double[][] tolerances = NumericalPropagator.tolerances(0.1, orbit, type);
    DormandPrince853Integrator integrator = new DormandPrince853Integrator(1.0, 600, tolerances[0], tolerances[1]);
    integrator.setInitialStepSize(60.0);
    NumericalPropagator propagator = new NumericalPropagator(integrator);
    propagator.addForceModel(new HolmesFeatherstoneAttractionModel(earth.getBodyFrame(), gravityField));
    propagator.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getSun()));
    propagator.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getMoon()));
    propagator.setOrbitType(type);
    propagator.resetInitialState(new SpacecraftState(orbit));
    return propagator;
}

Example 4 with ThirdBodyAttraction

use of org.orekit.forces.gravity.ThirdBodyAttraction in project Orekit by CS-SI.

the class FieldPropagation method main.

/**
 * Program entry point.
 * @param args program arguments (unused here)
 * @throws IOException
 * @throws OrekitException
 */
public static void main(String[] args) throws IOException, OrekitException {
    // the goal of this example is to make a Montecarlo simulation giving an error on the semiaxis,
    // the inclination and the RAAN. The interest of doing it with Orekit based on the
    // DerivativeStructure is that instead of doing a large number of propagation around the initial
    // point we will do a single propagation of the initial state, and thanks to the Taylor expansion
    // we will see the evolution of the std deviation of the position, which is divided in the
    // CrossTrack, the LongTrack and the Radial error.
    // configure Orekit
    File home = new File(System.getProperty("user.home"));
    File orekitData = new File(home, "orekit-data");
    if (!orekitData.exists()) {
        System.err.format(Locale.US, "Failed to find %s folder%n", orekitData.getAbsolutePath());
        System.err.format(Locale.US, "You need to download %s from the %s page and unzip it in %s for this tutorial to work%n", "orekit-data.zip", "https://www.orekit.org/forge/projects/orekit/files", home.getAbsolutePath());
        System.exit(1);
    }
    DataProvidersManager manager = DataProvidersManager.getInstance();
    manager.addProvider(new DirectoryCrawler(orekitData));
    // output file in user's home directory
    File workingDir = new File(System.getProperty("user.home"));
    File errorFile = new File(workingDir, "error.txt");
    System.out.println("Output file is in : " + errorFile.getAbsolutePath());
    PrintWriter PW = new PrintWriter(errorFile, "UTF-8");
    PW.printf("time \t\tCrossTrackErr \tLongTrackErr  \tRadialErr \tTotalErr%n");
    // setting the parameters of the simulation
    // Order of derivation of the DerivativeStructures
    int params = 3;
    int order = 3;
    DSFactory factory = new DSFactory(params, order);
    // number of samples of the montecarlo simulation
    int montecarlo_size = 100;
    // nominal values of the Orbital parameters
    double a_nominal = 7.278E6;
    double e_nominal = 1e-3;
    double i_nominal = FastMath.toRadians(98.3);
    double pa_nominal = FastMath.PI / 2;
    double raan_nominal = 0.0;
    double ni_nominal = 0.0;
    // mean of the gaussian curve for each of the errors around the nominal values
    // {a, i, RAAN}
    double[] mean = { 0, 0, 0 };
    // standard deviation of the gaussian curve for each of the errors around the nominal values
    // {dA, dI, dRaan}
    double[] dAdIdRaan = { 5, FastMath.toRadians(1e-3), FastMath.toRadians(1e-3) };
    // time of integration
    double final_Dt = 1 * 60 * 60;
    // number of steps per orbit
    double num_step_orbit = 10;
    DerivativeStructure a_0 = factory.variable(0, a_nominal);
    DerivativeStructure e_0 = factory.constant(e_nominal);
    DerivativeStructure i_0 = factory.variable(1, i_nominal);
    DerivativeStructure pa_0 = factory.constant(pa_nominal);
    DerivativeStructure raan_0 = factory.variable(2, raan_nominal);
    DerivativeStructure ni_0 = factory.constant(ni_nominal);
    // sometimes we will need the field of the DerivativeStructure to build new instances
    Field<DerivativeStructure> field = a_0.getField();
    // sometimes we will need the zero of the DerivativeStructure to build new instances
    DerivativeStructure zero = field.getZero();
    // initializing the FieldAbsoluteDate with only the field it will generate the day J2000
    FieldAbsoluteDate<DerivativeStructure> date_0 = new FieldAbsoluteDate<>(field);
    // initialize a basic frame
    Frame frame = FramesFactory.getEME2000();
    // initialize the orbit
    double mu = 3.9860047e14;
    FieldKeplerianOrbit<DerivativeStructure> KO = new FieldKeplerianOrbit<>(a_0, e_0, i_0, pa_0, raan_0, ni_0, PositionAngle.ECCENTRIC, frame, date_0, mu);
    // step of integration (how many times per orbit we take the mesures)
    double int_step = KO.getKeplerianPeriod().getReal() / num_step_orbit;
    // random generator to conduct an
    long number = 23091991;
    RandomGenerator RG = new Well19937a(number);
    GaussianRandomGenerator NGG = new GaussianRandomGenerator(RG);
    UncorrelatedRandomVectorGenerator URVG = new UncorrelatedRandomVectorGenerator(mean, dAdIdRaan, NGG);
    double[][] rand_gen = new double[montecarlo_size][3];
    for (int jj = 0; jj < montecarlo_size; jj++) {
        rand_gen[jj] = URVG.nextVector();
    }
    // 
    FieldSpacecraftState<DerivativeStructure> SS_0 = new FieldSpacecraftState<>(KO);
    // adding force models
    ForceModel fModel_Sun = new ThirdBodyAttraction(CelestialBodyFactory.getSun());
    ForceModel fModel_Moon = new ThirdBodyAttraction(CelestialBodyFactory.getMoon());
    ForceModel fModel_HFAM = new HolmesFeatherstoneAttractionModel(FramesFactory.getITRF(IERSConventions.IERS_2010, true), GravityFieldFactory.getNormalizedProvider(18, 18));
    // setting an hipparchus field integrator
    OrbitType type = OrbitType.CARTESIAN;
    double[][] tolerance = NumericalPropagator.tolerances(0.001, KO.toOrbit(), type);
    AdaptiveStepsizeFieldIntegrator<DerivativeStructure> integrator = new DormandPrince853FieldIntegrator<>(field, 0.001, 200, tolerance[0], tolerance[1]);
    integrator.setInitialStepSize(zero.add(60));
    // setting of the field propagator, we used the numerical one in order to add the third body attraction
    // and the holmes featherstone force models
    FieldNumericalPropagator<DerivativeStructure> numProp = new FieldNumericalPropagator<>(field, integrator);
    numProp.setOrbitType(type);
    numProp.setInitialState(SS_0);
    numProp.addForceModel(fModel_Sun);
    numProp.addForceModel(fModel_Moon);
    numProp.addForceModel(fModel_HFAM);
    // with the master mode we will calulcate and print the error on every fixed step on the file error.txt
    // we defined the StepHandler to do that giving him the random number generator,
    // the size of the montecarlo simulation and the initial date
    numProp.setMasterMode(zero.add(int_step), new MyStepHandler<DerivativeStructure>(rand_gen, montecarlo_size, date_0, PW));
    // 
    long START = System.nanoTime();
    FieldSpacecraftState<DerivativeStructure> finalState = numProp.propagate(date_0.shiftedBy(final_Dt));
    long STOP = System.nanoTime();
    System.out.println((STOP - START) / 1E6 + " ms");
    System.out.println(finalState.getDate());
    PW.close();
}

Example 5 with ThirdBodyAttraction

use of org.orekit.forces.gravity.ThirdBodyAttraction in project Orekit by CS-SI.

the class KalmanOrbitDeterminationTest method createPropagatorBuilder.

/**
 * Create a propagator builder from input parameters
 * @param parser input file parser
 * @param conventions IERS conventions to use
 * @param gravityField gravity field
 * @param body central body
 * @param orbit first orbit estimate
 * @return propagator builder
 * @throws NoSuchElementException if input parameters are missing
 * @throws OrekitException if body frame cannot be created
 */
private NumericalPropagatorBuilder createPropagatorBuilder(final KeyValueFileParser<ParameterKey> parser, final IERSConventions conventions, final NormalizedSphericalHarmonicsProvider gravityField, final OneAxisEllipsoid body, final Orbit orbit) throws NoSuchElementException, OrekitException {
    final double minStep;
    if (!parser.containsKey(ParameterKey.PROPAGATOR_MIN_STEP)) {
        minStep = 0.001;
    } else {
        minStep = parser.getDouble(ParameterKey.PROPAGATOR_MIN_STEP);
    }
    final double maxStep;
    if (!parser.containsKey(ParameterKey.PROPAGATOR_MAX_STEP)) {
        maxStep = 300;
    } else {
        maxStep = parser.getDouble(ParameterKey.PROPAGATOR_MAX_STEP);
    }
    final double dP;
    if (!parser.containsKey(ParameterKey.PROPAGATOR_POSITION_ERROR)) {
        dP = 10.0;
    } else {
        dP = parser.getDouble(ParameterKey.PROPAGATOR_POSITION_ERROR);
    }
    final double positionScale;
    if (!parser.containsKey(ParameterKey.ESTIMATOR_ORBITAL_PARAMETERS_POSITION_SCALE)) {
        positionScale = dP;
    } else {
        positionScale = parser.getDouble(ParameterKey.ESTIMATOR_ORBITAL_PARAMETERS_POSITION_SCALE);
    }
    final NumericalPropagatorBuilder propagatorBuilder = new NumericalPropagatorBuilder(orbit, new DormandPrince853IntegratorBuilder(minStep, maxStep, dP), PositionAngle.MEAN, positionScale);
    // initial mass
    final double mass;
    if (!parser.containsKey(ParameterKey.MASS)) {
        mass = 1000.0;
    } else {
        mass = parser.getDouble(ParameterKey.MASS);
    }
    propagatorBuilder.setMass(mass);
    // gravity field force model
    propagatorBuilder.addForceModel(new HolmesFeatherstoneAttractionModel(body.getBodyFrame(), gravityField));
    // ocean tides force model
    if (parser.containsKey(ParameterKey.OCEAN_TIDES_DEGREE) && parser.containsKey(ParameterKey.OCEAN_TIDES_ORDER)) {
        final int degree = parser.getInt(ParameterKey.OCEAN_TIDES_DEGREE);
        final int order = parser.getInt(ParameterKey.OCEAN_TIDES_ORDER);
        if (degree > 0 && order > 0) {
            propagatorBuilder.addForceModel(new OceanTides(body.getBodyFrame(), gravityField.getAe(), gravityField.getMu(), degree, order, conventions, TimeScalesFactory.getUT1(conventions, true)));
        }
    }
    // solid tides force model
    List<CelestialBody> solidTidesBodies = new ArrayList<CelestialBody>();
    if (parser.containsKey(ParameterKey.SOLID_TIDES_SUN) && parser.getBoolean(ParameterKey.SOLID_TIDES_SUN)) {
        solidTidesBodies.add(CelestialBodyFactory.getSun());
    }
    if (parser.containsKey(ParameterKey.SOLID_TIDES_MOON) && parser.getBoolean(ParameterKey.SOLID_TIDES_MOON)) {
        solidTidesBodies.add(CelestialBodyFactory.getMoon());
    }
    if (!solidTidesBodies.isEmpty()) {
        propagatorBuilder.addForceModel(new SolidTides(body.getBodyFrame(), gravityField.getAe(), gravityField.getMu(), gravityField.getTideSystem(), conventions, TimeScalesFactory.getUT1(conventions, true), solidTidesBodies.toArray(new CelestialBody[solidTidesBodies.size()])));
    }
    // third body attraction
    if (parser.containsKey(ParameterKey.THIRD_BODY_SUN) && parser.getBoolean(ParameterKey.THIRD_BODY_SUN)) {
        propagatorBuilder.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getSun()));
    }
    if (parser.containsKey(ParameterKey.THIRD_BODY_MOON) && parser.getBoolean(ParameterKey.THIRD_BODY_MOON)) {
        propagatorBuilder.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getMoon()));
    }
    // drag
    if (parser.containsKey(ParameterKey.DRAG) && parser.getBoolean(ParameterKey.DRAG)) {
        final double cd = parser.getDouble(ParameterKey.DRAG_CD);
        final double area = parser.getDouble(ParameterKey.DRAG_AREA);
        final boolean cdEstimated = parser.getBoolean(ParameterKey.DRAG_CD_ESTIMATED);
        MarshallSolarActivityFutureEstimation msafe = new MarshallSolarActivityFutureEstimation("(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\\p{Digit}\\p{Digit}\\p{Digit}\\p{Digit}F10\\.(?:txt|TXT)", MarshallSolarActivityFutureEstimation.StrengthLevel.AVERAGE);
        DataProvidersManager manager = DataProvidersManager.getInstance();
        manager.feed(msafe.getSupportedNames(), msafe);
        Atmosphere atmosphere = new DTM2000(msafe, CelestialBodyFactory.getSun(), body);
        propagatorBuilder.addForceModel(new DragForce(atmosphere, new IsotropicDrag(area, cd)));
        if (cdEstimated) {
            for (final ParameterDriver driver : propagatorBuilder.getPropagationParametersDrivers().getDrivers()) {
                if (driver.getName().equals(DragSensitive.DRAG_COEFFICIENT)) {
                    driver.setSelected(true);
                }
            }
        }
    }
    // solar radiation pressure
    if (parser.containsKey(ParameterKey.SOLAR_RADIATION_PRESSURE) && parser.getBoolean(ParameterKey.SOLAR_RADIATION_PRESSURE)) {
        final double cr = parser.getDouble(ParameterKey.SOLAR_RADIATION_PRESSURE_CR);
        final double area = parser.getDouble(ParameterKey.SOLAR_RADIATION_PRESSURE_AREA);
        final boolean cREstimated = parser.getBoolean(ParameterKey.SOLAR_RADIATION_PRESSURE_CR_ESTIMATED);
        propagatorBuilder.addForceModel(new SolarRadiationPressure(CelestialBodyFactory.getSun(), body.getEquatorialRadius(), new IsotropicRadiationSingleCoefficient(area, cr)));
        if (cREstimated) {
            for (final ParameterDriver driver : propagatorBuilder.getPropagationParametersDrivers().getDrivers()) {
                if (driver.getName().equals(RadiationSensitive.REFLECTION_COEFFICIENT)) {
                    driver.setSelected(true);
                }
            }
        }
    }
    // post-Newtonian correction force due to general relativity
    if (parser.containsKey(ParameterKey.GENERAL_RELATIVITY) && parser.getBoolean(ParameterKey.GENERAL_RELATIVITY)) {
        propagatorBuilder.addForceModel(new Relativity(gravityField.getMu()));
    }
    // extra polynomial accelerations
    if (parser.containsKey(ParameterKey.POLYNOMIAL_ACCELERATION_NAME)) {
        final String[] names = parser.getStringArray(ParameterKey.POLYNOMIAL_ACCELERATION_NAME);
        final Vector3D[] directions = parser.getVectorArray(ParameterKey.POLYNOMIAL_ACCELERATION_DIRECTION_X, ParameterKey.POLYNOMIAL_ACCELERATION_DIRECTION_Y, ParameterKey.POLYNOMIAL_ACCELERATION_DIRECTION_Z);
        final List<String>[] coefficients = parser.getStringsListArray(ParameterKey.POLYNOMIAL_ACCELERATION_COEFFICIENTS, ',');
        final boolean[] estimated = parser.getBooleanArray(ParameterKey.POLYNOMIAL_ACCELERATION_ESTIMATED);
        for (int i = 0; i < names.length; ++i) {
            final PolynomialParametricAcceleration ppa = new PolynomialParametricAcceleration(directions[i], true, names[i], null, coefficients[i].size() - 1);
            for (int k = 0; k < coefficients[i].size(); ++k) {
                final ParameterDriver driver = ppa.getParameterDriver(names[i] + "[" + k + "]");
                driver.setValue(Double.parseDouble(coefficients[i].get(k)));
                driver.setSelected(estimated[i]);
            }
            propagatorBuilder.addForceModel(ppa);
        }
    }
    return propagatorBuilder;
}