Examples with OrekitFixedStepHandler org.orekit.propagation.sampling.OrekitFixedStepHandler used on opensource projects

Example 11 with OrekitFixedStepHandler

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

the class TabulatedProviderTest method checkError.

private double checkError(final AbsoluteDate start, AbsoluteDate end, double checkingRate, final AttitudeProvider referenceProvider, TabulatedProvider provider) throws OrekitException {
    // prepare an interpolating provider, using only internal steps
    // (i.e. ignoring interpolation near boundaries)
    Propagator interpolatingPropagator = new KeplerianPropagator(circOrbit.shiftedBy(start.durationFrom(circOrbit.getDate())));
    interpolatingPropagator.setAttitudeProvider(provider);
    // compute interpolation error on the internal steps .
    final double[] error = new double[1];
    interpolatingPropagator.setMasterMode(checkingRate, new OrekitFixedStepHandler() {

        public void init(SpacecraftState s0, AbsoluteDate t, double step) {
            error[0] = 0.0;
        }

        public void handleStep(SpacecraftState currentState, boolean isLast) throws OrekitException {
            Attitude interpolated = currentState.getAttitude();
            Attitude reference = referenceProvider.getAttitude(currentState.getOrbit(), currentState.getDate(), currentState.getFrame());
            double localError = Rotation.distance(interpolated.getRotation(), reference.getRotation());
            error[0] = FastMath.max(error[0], localError);
        }
    });
    interpolatingPropagator.propagate(end);
    return error[0];
}

Example 12 with OrekitFixedStepHandler

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

the class EcksteinHechlerPropagatorTest method fixedStep.

@Test
public void fixedStep() throws OrekitException {
    final KeplerianOrbit orbit = new KeplerianOrbit(7.8e6, 0.032, 0.4, 0.1, 0.2, 0.3, PositionAngle.TRUE, FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH, 3.986004415e14);
    EcksteinHechlerPropagator propagator = new EcksteinHechlerPropagator(orbit, provider);
    final double step = 100.0;
    propagator.setMasterMode(step, new OrekitFixedStepHandler() {

        private AbsoluteDate previous;

        public void handleStep(SpacecraftState currentState, boolean isLast) throws OrekitException {
            if (previous != null) {
                Assert.assertEquals(step, currentState.getDate().durationFrom(previous), 1.0e-10);
            }
            previous = currentState.getDate();
        }
    });
    AbsoluteDate farTarget = AbsoluteDate.J2000_EPOCH.shiftedBy(10000.0);
    propagator.propagate(farTarget);
}

Example 13 with OrekitFixedStepHandler

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

the class EcksteinHechlerPropagatorTest method testIssue224Backward.

@Test
public void testIssue224Backward() throws OrekitException, IOException, ClassNotFoundException {
    AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(154.);
    Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    Frame eme2000 = FramesFactory.getEME2000();
    Vector3D pole = itrf.getTransformTo(eme2000, date).transformVector(Vector3D.PLUS_K);
    Frame poleAligned = new Frame(FramesFactory.getEME2000(), new Transform(date, new Rotation(pole, Vector3D.PLUS_K)), "pole aligned", true);
    CircularOrbit initial = new CircularOrbit(7208669.8179538045, 1.3740461966386876E-4, -3.2364250248363356E-5, FastMath.toRadians(97.40236024565775), FastMath.toRadians(166.15873160992115), FastMath.toRadians(90.1282370098961), PositionAngle.MEAN, poleAligned, date, provider.getMu());
    EcksteinHechlerPropagator propagator = new EcksteinHechlerPropagator(initial, new LofOffset(poleAligned, LOFType.VVLH), 1000.0, provider);
    propagator.addAdditionalStateProvider(new SevenProvider());
    propagator.setEphemerisMode();
    // Impulsive burns
    final AbsoluteDate burn1Date = initial.getDate().shiftedBy(-200);
    ImpulseManeuver<DateDetector> impulsiveBurn1 = new ImpulseManeuver<DateDetector>(new DateDetector(burn1Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn1);
    final AbsoluteDate burn2Date = initial.getDate().shiftedBy(-300);
    ImpulseManeuver<DateDetector> impulsiveBurn2 = new ImpulseManeuver<DateDetector>(new DateDetector(burn2Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn2);
    propagator.propagate(initial.getDate().shiftedBy(-400));
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    ObjectOutputStream oos = new ObjectOutputStream(bos);
    oos.writeObject(propagator.getGeneratedEphemeris());
    Assert.assertTrue(bos.size() > 2950);
    Assert.assertTrue(bos.size() < 3050);
    ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
    ObjectInputStream ois = new ObjectInputStream(bis);
    BoundedPropagator ephemeris = (BoundedPropagator) ois.readObject();
    ephemeris.setMasterMode(10, new OrekitFixedStepHandler() {

        public void handleStep(SpacecraftState currentState, boolean isLast) {
            if (currentState.getDate().durationFrom(burn1Date) > 0.001) {
                Assert.assertEquals(97.402, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn1Date) < -0.001 && currentState.getDate().durationFrom(burn2Date) > 0.001) {
                Assert.assertEquals(98.164, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn2Date) < -0.001) {
                Assert.assertEquals(99.273, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            }
        }
    });
    ephemeris.propagate(ephemeris.getMinDate());
}

Example 14 with OrekitFixedStepHandler

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

the class EcksteinHechlerPropagatorTest method testIssue224Forward.

@Test
public void testIssue224Forward() throws OrekitException, IOException, ClassNotFoundException {
    AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(154.);
    Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    Frame eme2000 = FramesFactory.getEME2000();
    Vector3D pole = itrf.getTransformTo(eme2000, date).transformVector(Vector3D.PLUS_K);
    Frame poleAligned = new Frame(FramesFactory.getEME2000(), new Transform(date, new Rotation(pole, Vector3D.PLUS_K)), "pole aligned", true);
    CircularOrbit initial = new CircularOrbit(7208669.8179538045, 1.3740461966386876E-4, -3.2364250248363356E-5, FastMath.toRadians(97.40236024565775), FastMath.toRadians(166.15873160992115), FastMath.toRadians(90.1282370098961), PositionAngle.MEAN, poleAligned, date, provider.getMu());
    EcksteinHechlerPropagator propagator = new EcksteinHechlerPropagator(initial, new LofOffset(poleAligned, LOFType.VVLH), 1000.0, provider);
    propagator.addAdditionalStateProvider(new SevenProvider());
    propagator.setEphemerisMode();
    // Impulsive burns
    final AbsoluteDate burn1Date = initial.getDate().shiftedBy(200);
    ImpulseManeuver<DateDetector> impulsiveBurn1 = new ImpulseManeuver<DateDetector>(new DateDetector(burn1Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn1);
    final AbsoluteDate burn2Date = initial.getDate().shiftedBy(300);
    ImpulseManeuver<DateDetector> impulsiveBurn2 = new ImpulseManeuver<DateDetector>(new DateDetector(burn2Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn2);
    propagator.propagate(initial.getDate().shiftedBy(400));
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    ObjectOutputStream oos = new ObjectOutputStream(bos);
    oos.writeObject(propagator.getGeneratedEphemeris());
    Assert.assertTrue(bos.size() > 2950);
    Assert.assertTrue(bos.size() < 3050);
    ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
    ObjectInputStream ois = new ObjectInputStream(bis);
    BoundedPropagator ephemeris = (BoundedPropagator) ois.readObject();
    ephemeris.setMasterMode(10, new OrekitFixedStepHandler() {

        public void handleStep(SpacecraftState currentState, boolean isLast) {
            if (currentState.getDate().durationFrom(burn1Date) < -0.001) {
                Assert.assertEquals(97.402, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn1Date) > 0.001 && currentState.getDate().durationFrom(burn2Date) < -0.001) {
                Assert.assertEquals(98.183, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn2Date) > 0.001) {
                Assert.assertEquals(99.310, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            }
        }
    });
    ephemeris.propagate(ephemeris.getMaxDate());
}

Example 15 with OrekitFixedStepHandler

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

the class EarthObservation method main.

/**
 * Program entry point.
 * @param args program arguments (unused here)
 */
public static void main(String[] args) {
    try {
        // 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));
        final SortedSet<String> output = new TreeSet<String>();
        // Initial state definition : date, orbit
        final AbsoluteDate initialDate = new AbsoluteDate(2004, 01, 01, 23, 30, 00.000, TimeScalesFactory.getUTC());
        final Vector3D position = new Vector3D(-6142438.668, 3492467.560, -25767.25680);
        final Vector3D velocity = new Vector3D(505.8479685, 942.7809215, 7435.922231);
        final Orbit initialOrbit = new KeplerianOrbit(new PVCoordinates(position, velocity), FramesFactory.getEME2000(), initialDate, Constants.EIGEN5C_EARTH_MU);
        // Attitudes sequence definition
        final AttitudeProvider dayObservationLaw = new LofOffset(initialOrbit.getFrame(), LOFType.VVLH, RotationOrder.XYZ, FastMath.toRadians(20), FastMath.toRadians(40), 0);
        final AttitudeProvider nightRestingLaw = new LofOffset(initialOrbit.getFrame(), LOFType.VVLH);
        final PVCoordinatesProvider sun = CelestialBodyFactory.getSun();
        final PVCoordinatesProvider earth = CelestialBodyFactory.getEarth();
        final EventDetector dayNightEvent = new EclipseDetector(sun, 696000000., earth, Constants.WGS84_EARTH_EQUATORIAL_RADIUS).withHandler(new ContinueOnEvent<EclipseDetector>());
        final EventDetector nightDayEvent = new EclipseDetector(sun, 696000000., earth, Constants.WGS84_EARTH_EQUATORIAL_RADIUS).withHandler(new ContinueOnEvent<EclipseDetector>());
        final AttitudesSequence attitudesSequence = new AttitudesSequence();
        final AttitudesSequence.SwitchHandler switchHandler = new AttitudesSequence.SwitchHandler() {

            public void switchOccurred(AttitudeProvider preceding, AttitudeProvider following, SpacecraftState s) {
                if (preceding == dayObservationLaw) {
                    output.add(s.getDate() + ": switching to night law");
                } else {
                    output.add(s.getDate() + ": switching to day law");
                }
            }
        };
        attitudesSequence.addSwitchingCondition(dayObservationLaw, nightRestingLaw, dayNightEvent, false, true, 10.0, AngularDerivativesFilter.USE_R, switchHandler);
        attitudesSequence.addSwitchingCondition(nightRestingLaw, dayObservationLaw, nightDayEvent, true, false, 10.0, AngularDerivativesFilter.USE_R, switchHandler);
        if (dayNightEvent.g(new SpacecraftState(initialOrbit)) >= 0) {
            // initial position is in daytime
            attitudesSequence.resetActiveProvider(dayObservationLaw);
        } else {
            // initial position is in nighttime
            attitudesSequence.resetActiveProvider(nightRestingLaw);
        }
        // Propagator : consider the analytical Eckstein-Hechler model
        final Propagator propagator = new EcksteinHechlerPropagator(initialOrbit, attitudesSequence, 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);
        // Register the switching events to the propagator
        attitudesSequence.registerSwitchEvents(propagator);
        propagator.setMasterMode(180.0, new OrekitFixedStepHandler() {

            public void init(final SpacecraftState s0, final AbsoluteDate t) {
            }

            public void handleStep(SpacecraftState currentState, boolean isLast) throws OrekitException {
                DecimalFormatSymbols angleDegree = new DecimalFormatSymbols(Locale.US);
                angleDegree.setDecimalSeparator('\u00b0');
                DecimalFormat ad = new DecimalFormat(" 00.000;-00.000", angleDegree);
                // the Earth position in spacecraft frame should be along spacecraft Z axis
                // during nigthtime and away from it during daytime due to roll and pitch offsets
                final Vector3D earth = currentState.toTransform().transformPosition(Vector3D.ZERO);
                final double pointingOffset = Vector3D.angle(earth, Vector3D.PLUS_K);
                // the g function is the eclipse indicator, its an angle between Sun and Earth limb,
                // positive when Sun is outside of Earth limb, negative when Sun is hidden by Earth limb
                final double eclipseAngle = dayNightEvent.g(currentState);
                output.add(currentState.getDate() + " " + ad.format(FastMath.toDegrees(eclipseAngle)) + " " + ad.format(FastMath.toDegrees(pointingOffset)));
            }
        });
        // Propagate from the initial date for the fixed duration
        SpacecraftState finalState = propagator.propagate(initialDate.shiftedBy(12600.));
        // to make sure out of orders calls between step handler and event handlers don't mess things up
        for (final String line : output) {
            System.out.println(line);
        }
        System.out.println("Propagation ended at " + finalState.getDate());
    } catch (OrekitException oe) {
        System.err.println(oe.getMessage());
    }
}