Examples with Frame org.orekit.frames.Frame used on opensource projects

Example 41 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class DSSTPropagatorTest method testPropagationWithCentralBody.

@Test
public void testPropagationWithCentralBody() throws Exception {
    // Central Body geopotential 4x4
    final UnnormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getUnnormalizedProvider(4, 4);
    final Frame earthFrame = CelestialBodyFactory.getEarth().getBodyOrientedFrame();
    // GPS Orbit
    final AbsoluteDate initDate = new AbsoluteDate(2007, 4, 16, 0, 46, 42.400, TimeScalesFactory.getUTC());
    final Orbit orbit = new KeplerianOrbit(26559890., 0.0041632, FastMath.toRadians(55.2), FastMath.toRadians(315.4985), FastMath.toRadians(130.7562), FastMath.toRadians(44.2377), PositionAngle.MEAN, FramesFactory.getEME2000(), initDate, provider.getMu());
    // Set propagator with state and force model
    setDSSTProp(new SpacecraftState(orbit));
    dsstProp.addForceModel(new DSSTZonal(provider, 4, 3, 9));
    dsstProp.addForceModel(new DSSTTesseral(earthFrame, Constants.WGS84_EARTH_ANGULAR_VELOCITY, provider, 4, 4, 4, 8, 4, 4, 2));
    // 5 days propagation
    final SpacecraftState state = dsstProp.propagate(initDate.shiftedBy(5. * 86400.));
    // Ref GTDS_DSST:
    // a    = 26559.92081 km
    // h/ey =   0.2731622444E-03
    // k/ex =   0.4164167597E-02
    // p/hy =  -0.3399607878
    // q/hx =   0.3971568634
    // lM   = 140.6375352°
    Assert.assertEquals(26559920.81, state.getA(), 1.e-1);
    Assert.assertEquals(0.2731622444E-03, state.getEquinoctialEx(), 2.e-8);
    Assert.assertEquals(0.4164167597E-02, state.getEquinoctialEy(), 2.e-8);
    Assert.assertEquals(-0.3399607878, state.getHx(), 5.e-8);
    Assert.assertEquals(0.3971568634, state.getHy(), 2.e-6);
    Assert.assertEquals(140.6375352, FastMath.toDegrees(MathUtils.normalizeAngle(state.getLM(), FastMath.PI)), 5.e-3);
}

Example 42 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class DSSTPropagatorTest method testIssueMeanInclination.

@Test
public void testIssueMeanInclination() throws OrekitException {
    final double earthAe = 6378137.0;
    final double earthMu = 3.9860044E14;
    final double earthJ2 = 0.0010826;
    // Initialize the DSST propagator with only J2 perturbation
    Orbit orb = new KeplerianOrbit(new TimeStampedPVCoordinates(new AbsoluteDate("1992-10-08T15:20:38.821", TimeScalesFactory.getUTC()), new Vector3D(5392808.809823, -4187618.3357927715, -44206.638015847195), new Vector3D(2337.4472786270794, 2474.0146611860464, 6778.507766114648)), FramesFactory.getTOD(false), earthMu);
    final SpacecraftState ss = new SpacecraftState(orb);
    final UnnormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getUnnormalizedProvider(earthAe, earthMu, TideSystem.UNKNOWN, new double[][] { { 0.0 }, { 0.0 }, { -earthJ2 } }, new double[][] { { 0.0 }, { 0.0 }, { 0.0 } });
    final Frame earthFrame = CelestialBodyFactory.getEarth().getBodyOrientedFrame();
    DSSTForceModel zonal = new DSSTZonal(provider, 2, 1, 5);
    DSSTForceModel tesseral = new DSSTTesseral(earthFrame, Constants.WGS84_EARTH_ANGULAR_VELOCITY, provider, 2, 0, 0, 2, 2, 0, 0);
    final Collection<DSSTForceModel> forces = new ArrayList<DSSTForceModel>();
    forces.add(zonal);
    forces.add(tesseral);
    // Computes J2 mean elements using the DSST osculating to mean converter
    final Orbit meanOrb = DSSTPropagator.computeMeanState(ss, null, forces).getOrbit();
    Assert.assertEquals(0.0164196, FastMath.toDegrees(orb.getI() - meanOrb.getI()), 1.0e-7);
}

Example 43 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class DSSTPropagatorTest method testOsculatingToMeanState.

@Test
public void testOsculatingToMeanState() throws IllegalArgumentException, OrekitException {
    final SpacecraftState meanState = getGEOState();
    final UnnormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getUnnormalizedProvider(2, 0);
    final Frame earthFrame = CelestialBodyFactory.getEarth().getBodyOrientedFrame();
    DSSTForceModel zonal = new DSSTZonal(provider, 2, 1, 5);
    DSSTForceModel tesseral = new DSSTTesseral(earthFrame, Constants.WGS84_EARTH_ANGULAR_VELOCITY, provider, 2, 0, 0, 2, 2, 0, 0);
    final Collection<DSSTForceModel> forces = new ArrayList<DSSTForceModel>();
    forces.add(zonal);
    forces.add(tesseral);
    final SpacecraftState osculatingState = DSSTPropagator.computeOsculatingState(meanState, null, forces);
    // there are no Gaussian force models, we don't need an attitude provider
    final SpacecraftState computedMeanState = DSSTPropagator.computeMeanState(osculatingState, null, forces);
    Assert.assertEquals(meanState.getA(), computedMeanState.getA(), 2.0e-8);
    Assert.assertEquals(0.0, Vector3D.distance(meanState.getPVCoordinates().getPosition(), computedMeanState.getPVCoordinates().getPosition()), 2.0e-8);
}

Example 44 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class OrbitDetermination method createBody.

/**
 * 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 body frame cannot be created
 */
private OneAxisEllipsoid createBody(final KeyValueFileParser<ParameterKey> parser) throws NoSuchElementException, OrekitException {
    final Frame bodyFrame;
    if (!parser.containsKey(ParameterKey.BODY_FRAME)) {
        bodyFrame = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    } else {
        bodyFrame = parser.getEarthFrame(ParameterKey.BODY_FRAME);
    }
    final double equatorialRadius;
    if (!parser.containsKey(ParameterKey.BODY_EQUATORIAL_RADIUS)) {
        equatorialRadius = Constants.WGS84_EARTH_EQUATORIAL_RADIUS;
    } else {
        equatorialRadius = parser.getDouble(ParameterKey.BODY_EQUATORIAL_RADIUS);
    }
    final double flattening;
    if (!parser.containsKey(ParameterKey.BODY_INVERSE_FLATTENING)) {
        flattening = Constants.WGS84_EARTH_FLATTENING;
    } else {
        flattening = 1.0 / parser.getDouble(ParameterKey.BODY_INVERSE_FLATTENING);
    }
    return new OneAxisEllipsoid(equatorialRadius, flattening, bodyFrame);
}

Example 45 with Frame

use of org.orekit.frames.Frame 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();
}