Examples with Propagator org.orekit.propagation.Propagator used on opensource projects

Example 81 with Propagator

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

the class LongitudeCrossingDetectorTest method testRegularCrossing.

@Test
public void testRegularCrossing() throws OrekitException {
    final OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    LongitudeCrossingDetector d = new LongitudeCrossingDetector(earth, FastMath.toRadians(10.0)).withMaxCheck(60).withThreshold(1.e-6).withHandler(new ContinueOnEvent<LongitudeCrossingDetector>());
    Assert.assertEquals(60.0, d.getMaxCheckInterval(), 1.0e-15);
    Assert.assertEquals(1.0e-6, d.getThreshold(), 1.0e-15);
    Assert.assertEquals(10.0, FastMath.toDegrees(d.getLongitude()), 1.0e-14);
    Assert.assertEquals(AbstractDetector.DEFAULT_MAX_ITER, d.getMaxIterationCount());
    Assert.assertSame(earth, d.getBody());
    final TimeScale utc = TimeScalesFactory.getUTC();
    final Vector3D position = new Vector3D(-6142438.668, 3492467.56, -25767.257);
    final Vector3D velocity = new Vector3D(505.848, 942.781, 7435.922);
    final AbsoluteDate date = new AbsoluteDate(2003, 9, 16, utc);
    final Orbit orbit = new EquinoctialOrbit(new PVCoordinates(position, velocity), FramesFactory.getEME2000(), date, Constants.EIGEN5C_EARTH_MU);
    Propagator propagator = new EcksteinHechlerPropagator(orbit, Constants.EIGEN5C_EARTH_EQUATORIAL_RADIUS, Constants.EIGEN5C_EARTH_MU, Constants.EIGEN5C_EARTH_C20, Constants.EIGEN5C_EARTH_C30, Constants.EIGEN5C_EARTH_C40, Constants.EIGEN5C_EARTH_C50, Constants.EIGEN5C_EARTH_C60);
    EventsLogger logger = new EventsLogger();
    propagator.addEventDetector(logger.monitorDetector(d));
    propagator.propagate(date.shiftedBy(Constants.JULIAN_DAY));
    AbsoluteDate previous = null;
    for (LoggedEvent e : logger.getLoggedEvents()) {
        SpacecraftState state = e.getState();
        double longitude = earth.transform(state.getPVCoordinates(earth.getBodyFrame()).getPosition(), earth.getBodyFrame(), null).getLongitude();
        Assert.assertEquals(10.0, FastMath.toDegrees(longitude), 1.6e-7);
        if (previous != null) {
            // same time interval regardless of increasing/decreasing,
            // as increasing/decreasing flag is irrelevant for this detector
            Assert.assertEquals(4954.70, state.getDate().durationFrom(previous), 1e10);
        }
        previous = state.getDate();
    }
    Assert.assertEquals(16, logger.getLoggedEvents().size());
}

Example 82 with Propagator

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

the class LongitudeExtremumDetectorTest method testNoCrossing.

@Test
public void testNoCrossing() throws OrekitException {
    final OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    LongitudeExtremumDetector d = new LongitudeExtremumDetector(earth).withMaxCheck(60).withThreshold(1.e-6).withHandler(new ContinueOnEvent<LongitudeExtremumDetector>());
    Assert.assertEquals(60.0, d.getMaxCheckInterval(), 1.0e-15);
    Assert.assertEquals(1.0e-6, d.getThreshold(), 1.0e-15);
    Assert.assertEquals(AbstractDetector.DEFAULT_MAX_ITER, d.getMaxIterationCount());
    Assert.assertSame(earth, d.getBody());
    final TimeScale utc = TimeScalesFactory.getUTC();
    final Vector3D position = new Vector3D(-6142438.668, 3492467.56, -25767.257);
    final Vector3D velocity = new Vector3D(505.848, 942.781, 7435.922);
    final AbsoluteDate date = new AbsoluteDate(2003, 9, 16, utc);
    final Orbit orbit = new EquinoctialOrbit(new PVCoordinates(position, velocity), FramesFactory.getEME2000(), date, Constants.EIGEN5C_EARTH_MU);
    Propagator propagator = new EcksteinHechlerPropagator(orbit, Constants.EIGEN5C_EARTH_EQUATORIAL_RADIUS, Constants.EIGEN5C_EARTH_MU, Constants.EIGEN5C_EARTH_C20, Constants.EIGEN5C_EARTH_C30, Constants.EIGEN5C_EARTH_C40, Constants.EIGEN5C_EARTH_C50, Constants.EIGEN5C_EARTH_C60);
    EventsLogger logger = new EventsLogger();
    propagator.addEventDetector(logger.monitorDetector(d));
    propagator.propagate(date.shiftedBy(Constants.JULIAN_DAY));
    Assert.assertEquals(0, logger.getLoggedEvents().size());
}

Example 83 with Propagator

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

the class PositionAngleDetectorTest method doTest.

private void doTest(final OrbitType orbitType, final PositionAngle positionAngle, final double angle, final int expectedCrossings) throws OrekitException {
    PositionAngleDetector d = new PositionAngleDetector(orbitType, positionAngle, angle).withMaxCheck(60).withThreshold(1.e-10).withHandler(new ContinueOnEvent<PositionAngleDetector>());
    Assert.assertEquals(60.0, d.getMaxCheckInterval(), 1.0e-15);
    Assert.assertEquals(1.0e-10, d.getThreshold(), 1.0e-15);
    Assert.assertEquals(orbitType, d.getOrbitType());
    Assert.assertEquals(positionAngle, d.getPositionAngle());
    Assert.assertEquals(angle, d.getAngle(), 1.0e-14);
    Assert.assertEquals(AbstractDetector.DEFAULT_MAX_ITER, d.getMaxIterationCount());
    final TimeScale utc = TimeScalesFactory.getUTC();
    final Vector3D position = new Vector3D(-6142438.668, 3492467.56, -25767.257);
    final Vector3D velocity = new Vector3D(506.0, 943.0, 7450);
    final AbsoluteDate date = new AbsoluteDate(2003, 9, 16, utc);
    final Orbit orbit = new CartesianOrbit(new PVCoordinates(position, velocity), FramesFactory.getEME2000(), date, Constants.EIGEN5C_EARTH_MU);
    Propagator propagator = new EcksteinHechlerPropagator(orbit, Constants.EIGEN5C_EARTH_EQUATORIAL_RADIUS, Constants.EIGEN5C_EARTH_MU, Constants.EIGEN5C_EARTH_C20, Constants.EIGEN5C_EARTH_C30, Constants.EIGEN5C_EARTH_C40, Constants.EIGEN5C_EARTH_C50, Constants.EIGEN5C_EARTH_C60);
    EventsLogger logger = new EventsLogger();
    propagator.addEventDetector(logger.monitorDetector(d));
    propagator.propagate(date.shiftedBy(Constants.JULIAN_DAY));
    double[] array = new double[6];
    for (LoggedEvent e : logger.getLoggedEvents()) {
        SpacecraftState state = e.getState();
        orbitType.mapOrbitToArray(state.getOrbit(), positionAngle, array, null);
        Assert.assertEquals(angle, MathUtils.normalizeAngle(array[5], angle), 1.0e-10);
    }
    Assert.assertEquals(15, logger.getLoggedEvents().size());
}

Example 84 with Propagator

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

the class NadirPointingTest method testSpin.

@Test
public void testSpin() throws OrekitException {
    // Elliptic earth shape
    OneAxisEllipsoid earthShape = new OneAxisEllipsoid(6378136.460, 1 / 298.257222101, itrf);
    // Create earth center pointing attitude provider
    NadirPointing law = new NadirPointing(FramesFactory.getEME2000(), earthShape);
    // Satellite on any position
    KeplerianOrbit orbit = new KeplerianOrbit(7178000.0, 1.e-4, FastMath.toRadians(50.), FastMath.toRadians(10.), FastMath.toRadians(20.), FastMath.toRadians(30.), PositionAngle.MEAN, FramesFactory.getEME2000(), date, mu);
    Propagator propagator = new KeplerianPropagator(orbit, law, mu, 2500.0);
    double h = 0.1;
    SpacecraftState sMinus = propagator.propagate(date.shiftedBy(-h));
    SpacecraftState s0 = propagator.propagate(date);
    SpacecraftState sPlus = propagator.propagate(date.shiftedBy(h));
    // check spin is consistent with attitude evolution
    double errorAngleMinus = Rotation.distance(sMinus.shiftedBy(h).getAttitude().getRotation(), s0.getAttitude().getRotation());
    double evolutionAngleMinus = Rotation.distance(sMinus.getAttitude().getRotation(), s0.getAttitude().getRotation());
    Assert.assertEquals(0.0, errorAngleMinus, 5.3e-9 * evolutionAngleMinus);
    double errorAnglePlus = Rotation.distance(s0.getAttitude().getRotation(), sPlus.shiftedBy(-h).getAttitude().getRotation());
    double evolutionAnglePlus = Rotation.distance(s0.getAttitude().getRotation(), sPlus.getAttitude().getRotation());
    Assert.assertEquals(0.0, errorAnglePlus, 8.1e-9 * evolutionAnglePlus);
    Vector3D spin0 = s0.getAttitude().getSpin();
    Rotation rM = sMinus.getAttitude().getRotation();
    Rotation rP = sPlus.getAttitude().getRotation();
    Vector3D reference = AngularCoordinates.estimateRate(rM, rP, 2 * h);
    Assert.assertTrue(Rotation.distance(rM, rP) > 2.0e-4);
    Assert.assertEquals(0.0, spin0.subtract(reference).getNorm(), 2.0e-6);
}

Example 85 with Propagator

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

the class InertialAttitudeTest method testSpin.

@Test
public void testSpin() throws OrekitException {
    AbsoluteDate date = new AbsoluteDate(new DateComponents(1970, 01, 01), new TimeComponents(3, 25, 45.6789), TimeScalesFactory.getUTC());
    AttitudeProvider law = new InertialProvider(new Rotation(new Vector3D(-0.64, 0.6, 0.48), 0.2, RotationConvention.VECTOR_OPERATOR));
    KeplerianOrbit orbit = new KeplerianOrbit(7178000.0, 1.e-4, FastMath.toRadians(50.), FastMath.toRadians(10.), FastMath.toRadians(20.), FastMath.toRadians(30.), PositionAngle.MEAN, FramesFactory.getEME2000(), date, 3.986004415e14);
    Propagator propagator = new KeplerianPropagator(orbit, law);
    double h = 100.0;
    SpacecraftState sMinus = propagator.propagate(date.shiftedBy(-h));
    SpacecraftState s0 = propagator.propagate(date);
    SpacecraftState sPlus = propagator.propagate(date.shiftedBy(h));
    // check spin is consistent with attitude evolution
    double errorAngleMinus = Rotation.distance(sMinus.shiftedBy(h).getAttitude().getRotation(), s0.getAttitude().getRotation());
    double evolutionAngleMinus = Rotation.distance(sMinus.getAttitude().getRotation(), s0.getAttitude().getRotation());
    Assert.assertEquals(0.0, errorAngleMinus, 1.0e-6 * evolutionAngleMinus);
    double errorAnglePlus = Rotation.distance(s0.getAttitude().getRotation(), sPlus.shiftedBy(-h).getAttitude().getRotation());
    double evolutionAnglePlus = Rotation.distance(s0.getAttitude().getRotation(), sPlus.getAttitude().getRotation());
    Assert.assertEquals(0.0, errorAnglePlus, 1.0e-6 * evolutionAnglePlus);
    // compute spin axis using finite differences
    Rotation rMinus = sMinus.getAttitude().getRotation();
    Rotation rPlus = sPlus.getAttitude().getRotation();
    Rotation dr = rPlus.compose(rMinus.revert(), RotationConvention.VECTOR_OPERATOR);
    Assert.assertEquals(0, dr.getAngle(), 1.0e-10);
    Vector3D spin0 = s0.getAttitude().getSpin();
    Assert.assertEquals(0, spin0.getNorm(), 1.0e-10);
}