Examples with EclipseDetector org.orekit.propagation.events.EclipseDetector used on opensource projects

Example 1 with EclipseDetector

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

the class AttitudesSequenceTest method doTestDayNightSwitchField.

private <T extends RealFieldElement<T>> void doTestDayNightSwitchField(final Field<T> field) throws OrekitException {
    // Initial state definition : date, orbit
    final FieldAbsoluteDate<T> initialDate = new FieldAbsoluteDate<>(field, 2004, 01, 01, 23, 30, 00.000, TimeScalesFactory.getUTC());
    final FieldVector3D<T> position = new FieldVector3D<>(field, new Vector3D(-6142438.668, 3492467.560, -25767.25680));
    final FieldVector3D<T> velocity = new FieldVector3D<>(field, new Vector3D(505.8479685, 942.7809215, 7435.922231));
    final FieldOrbit<T> initialOrbit = new FieldKeplerianOrbit<>(new FieldPVCoordinates<>(position, velocity), FramesFactory.getEME2000(), initialDate, Constants.EIGEN5C_EARTH_MU);
    // Attitudes sequence definition
    EventsLogger logger = new EventsLogger();
    final AttitudesSequence attitudesSequence = new AttitudesSequence();
    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 EclipseDetector ed = new EclipseDetector(sun, 696000000., earth, Constants.WGS84_EARTH_EQUATORIAL_RADIUS).withHandler(new ContinueOnEvent<EclipseDetector>() {

        private static final long serialVersionUID = 1L;

        int count = 0;

        public EventHandler.Action eventOccurred(final SpacecraftState s, final EclipseDetector d, final boolean increasing) {
            setInEclipse(s.getDate(), !increasing);
            if (count++ == 7) {
                return Action.STOP;
            } else {
                switch(count % 3) {
                    case 0:
                        return Action.CONTINUE;
                    case 1:
                        return Action.RESET_DERIVATIVES;
                    default:
                        return Action.RESET_STATE;
                }
            }
        }
    });
    final EventDetector monitored = logger.monitorDetector(ed);
    final Handler dayToNightHandler = new Handler(dayObservationLaw, nightRestingLaw);
    final Handler nightToDayHandler = new Handler(nightRestingLaw, dayObservationLaw);
    attitudesSequence.addSwitchingCondition(dayObservationLaw, nightRestingLaw, monitored, false, true, 300.0, AngularDerivativesFilter.USE_RRA, dayToNightHandler);
    attitudesSequence.addSwitchingCondition(nightRestingLaw, dayObservationLaw, monitored, true, false, 300.0, AngularDerivativesFilter.USE_RRA, nightToDayHandler);
    FieldSpacecraftState<T> initialState = new FieldSpacecraftState<>(initialOrbit);
    initialState = initialState.addAdditionalState("fortyTwo", field.getZero().add(42.0));
    if (ed.g(initialState.toSpacecraftState()) >= 0) {
        // initial position is in daytime
        setInEclipse(initialDate.toAbsoluteDate(), false);
        attitudesSequence.resetActiveProvider(dayObservationLaw);
    } else {
        // initial position is in nighttime
        setInEclipse(initialDate.toAbsoluteDate(), true);
        attitudesSequence.resetActiveProvider(nightRestingLaw);
    }
    // Propagator : consider the analytical Eckstein-Hechler model
    final FieldPropagator<T> propagator = new FieldEcksteinHechlerPropagator<T>(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(field, propagator);
    propagator.setMasterMode(field.getZero().add(60.0), new FieldOrekitFixedStepHandler<T>() {

        public void handleStep(FieldSpacecraftState<T> currentState, boolean isLast) throws OrekitException {
            // the Earth position in spacecraft frame should be along spacecraft Z axis
            // during night time and away from it during day time due to roll and pitch offsets
            final FieldVector3D<T> earth = currentState.toTransform().transformPosition(Vector3D.ZERO);
            final T pointingOffset = FieldVector3D.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 = ed.g(currentState.toSpacecraftState());
            if (currentState.getDate().durationFrom(lastChange).getReal() > 300) {
                if (inEclipse) {
                    Assert.assertTrue(eclipseAngle <= 0);
                    Assert.assertEquals(0.0, pointingOffset.getReal(), 1.0e-6);
                } else {
                    Assert.assertTrue(eclipseAngle >= 0);
                    Assert.assertEquals(0.767215, pointingOffset.getReal(), 1.0e-6);
                }
            } else {
                // we are in transition
                Assert.assertTrue(pointingOffset.getReal() + " " + (0.767215 - pointingOffset.getReal()), pointingOffset.getReal() <= 0.7672155);
            }
        }
    });
    // Propagate from the initial date for the fixed duration
    propagator.propagate(initialDate.shiftedBy(12600.));
    // as we have 2 switch events (even if they share the same underlying event detector),
    // and these events are triggered at both eclipse entry and exit, we get 8
    // raw events on 2 orbits
    Assert.assertEquals(8, logger.getLoggedEvents().size());
    // we have 4 attitudes switch on 2 orbits, 2 of each type
    Assert.assertEquals(2, dayToNightHandler.dates.size());
    Assert.assertEquals(2, nightToDayHandler.dates.size());
}

Example 2 with EclipseDetector

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

the class AttitudesSequenceTest method testDayNightSwitch.

@Test
public void testDayNightSwitch() throws OrekitException {
    // 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);
    final EventsLogger // Attitudes sequence definition
    logger = new EventsLogger();
    final AttitudesSequence attitudesSequence = new AttitudesSequence();
    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 EclipseDetector ed = new EclipseDetector(sun, 696000000., earth, Constants.WGS84_EARTH_EQUATORIAL_RADIUS).withHandler(new ContinueOnEvent<EclipseDetector>() {

        private static final long serialVersionUID = 1L;

        public EventHandler.Action eventOccurred(final SpacecraftState s, final EclipseDetector d, final boolean increasing) {
            setInEclipse(s.getDate(), !increasing);
            return EventHandler.Action.RESET_STATE;
        }
    });
    final EventDetector monitored = logger.monitorDetector(ed);
    final Handler dayToNightHandler = new Handler(dayObservationLaw, nightRestingLaw);
    final Handler nightToDayHandler = new Handler(nightRestingLaw, dayObservationLaw);
    attitudesSequence.addSwitchingCondition(dayObservationLaw, nightRestingLaw, monitored, false, true, 300.0, AngularDerivativesFilter.USE_RRA, dayToNightHandler);
    attitudesSequence.addSwitchingCondition(nightRestingLaw, dayObservationLaw, monitored, true, false, 300.0, AngularDerivativesFilter.USE_RRA, nightToDayHandler);
    SpacecraftState initialState = new SpacecraftState(initialOrbit);
    initialState = initialState.addAdditionalState("fortyTwo", 42.0);
    if (ed.g(initialState) >= 0) {
        // initial position is in daytime
        setInEclipse(initialDate, false);
        attitudesSequence.resetActiveProvider(dayObservationLaw);
    } else {
        // initial position is in nighttime
        setInEclipse(initialDate, true);
        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(60.0, new OrekitFixedStepHandler() {

        public void handleStep(SpacecraftState currentState, boolean isLast) throws OrekitException {
            // the Earth position in spacecraft frame should be along spacecraft Z axis
            // during night time and away from it during day time 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 = ed.g(currentState);
            if (currentState.getDate().durationFrom(lastChange) > 300) {
                if (inEclipse) {
                    Assert.assertTrue(eclipseAngle <= 0);
                    Assert.assertEquals(0.0, pointingOffset, 1.0e-6);
                } else {
                    Assert.assertTrue(eclipseAngle >= 0);
                    Assert.assertEquals(0.767215, pointingOffset, 1.0e-6);
                }
            } else {
                // we are in transition
                Assert.assertTrue(pointingOffset + " " + (0.767215 - pointingOffset), pointingOffset <= 0.7672155);
            }
        }
    });
    // Propagate from the initial date for the fixed duration
    propagator.propagate(initialDate.shiftedBy(12600.));
    // as we have 2 switch events (even if they share the same underlying event detector),
    // and these events are triggered at both eclipse entry and exit, we get 8
    // raw events on 2 orbits
    Assert.assertEquals(8, logger.getLoggedEvents().size());
    // we have 4 attitudes switch on 2 orbits, 2 of each type
    Assert.assertEquals(2, dayToNightHandler.dates.size());
    Assert.assertEquals(2, nightToDayHandler.dates.size());
}

Example 3 with EclipseDetector

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

the class EphemerisEventsTest method buildEclipsDetector.

private EclipseDetector buildEclipsDetector(final OrbitType type) throws OrekitException {
    double sunRadius = 696000000.;
    double earthRadius = 6400000.;
    EclipseDetector ecl = new EclipseDetector(60., 1.e-3, CelestialBodyFactory.getSun(), sunRadius, CelestialBodyFactory.getEarth(), earthRadius).withHandler(new EventHandler<EclipseDetector>() {

        public Action eventOccurred(SpacecraftState s, EclipseDetector detector, boolean increasing) throws OrekitException {
            Assert.assertEquals(type, s.getOrbit().getType());
            if (increasing) {
                ++inEclipsecounter;
            } else {
                ++outEclipsecounter;
            }
            return Action.CONTINUE;
        }
    });
    return ecl;
}

Example 4 with EclipseDetector

use of org.orekit.propagation.events.EclipseDetector 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());
    }
}