Examples with LofOffset org.orekit.attitudes.LofOffset used on opensource projects

Example 56 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class EphemerisTest method testNonResettableState.

@Test
public void testNonResettableState() {
    try {
        propagator.setAttitudeProvider(new LofOffset(inertialFrame, LOFType.VVLH));
        List<SpacecraftState> states = new ArrayList<SpacecraftState>();
        for (double dt = 0; dt >= -1200; dt -= 60.0) {
            states.add(propagator.propagate(initDate.shiftedBy(dt)));
        }
        new Ephemeris(states, 2).resetInitialState(propagator.getInitialState());
        Assert.fail("an exception should have been thrown");
    } catch (OrekitException oe) {
        Assert.assertEquals(OrekitMessages.NON_RESETABLE_STATE, oe.getSpecifier());
    }
}

Example 57 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class EphemerisTest method testAdditionalStates.

@Test
public void testAdditionalStates() throws OrekitException {
    final String name1 = "dt0";
    final String name2 = "dt1";
    propagator.setAttitudeProvider(new LofOffset(inertialFrame, LOFType.VVLH));
    List<SpacecraftState> states = new ArrayList<SpacecraftState>();
    for (double dt = 0; dt >= -1200; dt -= 60.0) {
        final SpacecraftState original = propagator.propagate(initDate.shiftedBy(dt));
        final SpacecraftState expanded = original.addAdditionalState(name2, original.getDate().durationFrom(finalDate));
        states.add(expanded);
    }
    final Propagator ephem = new Ephemeris(states, 2);
    ephem.addAdditionalStateProvider(new AdditionalStateProvider() {

        public String getName() {
            return name1;
        }

        public double[] getAdditionalState(SpacecraftState state) {
            return new double[] { state.getDate().durationFrom(initDate) };
        }
    });
    final String[] additional = ephem.getManagedAdditionalStates();
    Arrays.sort(additional);
    Assert.assertEquals(2, additional.length);
    Assert.assertEquals(name1, ephem.getManagedAdditionalStates()[0]);
    Assert.assertEquals(name2, ephem.getManagedAdditionalStates()[1]);
    Assert.assertTrue(ephem.isAdditionalStateManaged(name1));
    Assert.assertTrue(ephem.isAdditionalStateManaged(name2));
    Assert.assertFalse(ephem.isAdditionalStateManaged("not managed"));
    SpacecraftState s = ephem.propagate(initDate.shiftedBy(-270.0));
    Assert.assertEquals(-270.0, s.getAdditionalState(name1)[0], 1.0e-15);
    Assert.assertEquals(-86670.0, s.getAdditionalState(name2)[0], 1.0e-15);
}

Example 58 with LofOffset

use of org.orekit.attitudes.LofOffset 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());
    }
}