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

Example 1 with NadirPointing

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

the class FieldOfViewTest method testFOVPartiallyTruncatedAtLimb.

@Test
public void testFOVPartiallyTruncatedAtLimb() throws OrekitException {
    Utils.setDataRoot("regular-data");
    FieldOfView fov = new FieldOfView(Vector3D.PLUS_K, Vector3D.PLUS_I, FastMath.toRadians(40.0), 6, 0.0);
    OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    KeplerianOrbit orbit = new KeplerianOrbit(new PVCoordinates(new Vector3D(7.0e6, 1.0e6, 4.0e6), new Vector3D(-500.0, 8000.0, 1000.0)), FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH, Constants.EIGEN5C_EARTH_MU);
    Propagator propagator = new KeplerianPropagator(orbit);
    propagator.setAttitudeProvider(new NadirPointing(orbit.getFrame(), earth));
    SpacecraftState state = propagator.propagate(orbit.getDate().shiftedBy(1000.0));
    Transform inertToBody = state.getFrame().getTransformTo(earth.getBodyFrame(), state.getDate());
    Transform fovToBody = new Transform(state.getDate(), state.toTransform().getInverse(), inertToBody);
    List<List<GeodeticPoint>> footprint = fov.getFootprint(fovToBody, earth, FastMath.toRadians(1.0));
    Vector3D subSat = earth.projectToGround(state.getPVCoordinates(earth.getBodyFrame()).getPosition(), state.getDate(), earth.getBodyFrame());
    Assert.assertEquals(1, footprint.size());
    List<GeodeticPoint> loop = footprint.get(0);
    Assert.assertEquals(246, loop.size());
    double minEl = Double.POSITIVE_INFINITY;
    double maxEl = 0;
    double minDist = Double.POSITIVE_INFINITY;
    double maxDist = 0;
    for (int i = 0; i < loop.size(); ++i) {
        Assert.assertEquals(0.0, loop.get(i).getAltitude(), 3.0e-7);
        TopocentricFrame topo = new TopocentricFrame(earth, loop.get(i), "atLimb");
        final double elevation = topo.getElevation(state.getPVCoordinates().getPosition(), state.getFrame(), state.getDate());
        minEl = FastMath.min(minEl, elevation);
        maxEl = FastMath.max(maxEl, elevation);
        final double dist = Vector3D.distance(subSat, earth.transform(loop.get(i)));
        minDist = FastMath.min(minDist, dist);
        maxDist = FastMath.max(maxDist, dist);
    }
    Assert.assertEquals(0.0, FastMath.toDegrees(minEl), 2.0e-12);
    Assert.assertEquals(7.8897, FastMath.toDegrees(maxEl), 0.001);
    Assert.assertEquals(4584829.6, minDist, 1.0);
    Assert.assertEquals(5347029.8, maxDist, 1.0);
}

Example 2 with NadirPointing

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

the class FieldOfViewTest method testFOVAwayFromEarth.

@Test
public void testFOVAwayFromEarth() throws OrekitException {
    Utils.setDataRoot("regular-data");
    FieldOfView fov = new FieldOfView(Vector3D.MINUS_K, Vector3D.PLUS_I, FastMath.toRadians(3.0), 6, 0.0);
    OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    KeplerianOrbit orbit = new KeplerianOrbit(new PVCoordinates(new Vector3D(7.0e6, 1.0e6, 4.0e6), new Vector3D(-500.0, 8000.0, 1000.0)), FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH, Constants.EIGEN5C_EARTH_MU);
    Propagator propagator = new KeplerianPropagator(orbit);
    propagator.setAttitudeProvider(new NadirPointing(orbit.getFrame(), earth));
    SpacecraftState state = propagator.propagate(orbit.getDate().shiftedBy(1000.0));
    Transform inertToBody = state.getFrame().getTransformTo(earth.getBodyFrame(), state.getDate());
    Transform fovToBody = new Transform(state.getDate(), state.toTransform().getInverse(), inertToBody);
    List<List<GeodeticPoint>> footprint = fov.getFootprint(fovToBody, earth, FastMath.toRadians(1.0));
    Assert.assertEquals(0, footprint.size());
}

Example 3 with NadirPointing

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

the class FieldOfViewDetectorTest method testStopOnExit.

/**
 * check the default behavior to stop propagation on FoV exit.
 */
@Test
public void testStopOnExit() throws OrekitException {
    // setup
    double pi = FastMath.PI;
    // arbitrary date
    AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
    AbsoluteDate endDate = date.shiftedBy(Constants.JULIAN_DAY);
    Frame eci = FramesFactory.getGCRF();
    Frame ecef = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    BodyShape earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, ecef);
    GeodeticPoint gp = new GeodeticPoint(FastMath.toRadians(39), FastMath.toRadians(77), 0);
    TopocentricFrame topo = new TopocentricFrame(earth, gp, "topo");
    // iss like orbit
    KeplerianOrbit orbit = new KeplerianOrbit(6378137 + 400e3, 0, FastMath.toRadians(51.65), 0, 0, 0, PositionAngle.TRUE, eci, date, Constants.EGM96_EARTH_MU);
    AttitudeProvider attitude = new NadirPointing(eci, earth);
    // action
    FieldOfView fov = new FieldOfView(Vector3D.PLUS_K, Vector3D.PLUS_I, pi / 3, 16, 0);
    FieldOfViewDetector fovDetector = new FieldOfViewDetector(topo, fov).withMaxCheck(5.0);
    EventsLogger logger = new EventsLogger();
    Propagator prop = new KeplerianPropagator(orbit, attitude);
    prop.addEventDetector(logger.monitorDetector(fovDetector));
    prop.propagate(endDate);
    List<LoggedEvent> actual = logger.getLoggedEvents();
    // verify
    // check we have an entry and an exit event.
    Assert.assertEquals(2, actual.size());
}

Example 4 with NadirPointing

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

the class FieldOfViewTest method testNadirHexagonalFootprint.

@Test
public void testNadirHexagonalFootprint() throws OrekitException {
    Utils.setDataRoot("regular-data");
    FieldOfView fov = new FieldOfView(Vector3D.PLUS_K, Vector3D.PLUS_I, FastMath.toRadians(3.0), 6, 0.0);
    OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    KeplerianOrbit orbit = new KeplerianOrbit(new PVCoordinates(new Vector3D(7.0e6, 1.0e6, 4.0e6), new Vector3D(-500.0, 8000.0, 1000.0)), FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH, Constants.EIGEN5C_EARTH_MU);
    Propagator propagator = new KeplerianPropagator(orbit);
    propagator.setAttitudeProvider(new NadirPointing(orbit.getFrame(), earth));
    SpacecraftState state = propagator.propagate(orbit.getDate().shiftedBy(1000.0));
    Transform inertToBody = state.getFrame().getTransformTo(earth.getBodyFrame(), state.getDate());
    Transform fovToBody = new Transform(state.getDate(), state.toTransform().getInverse(), inertToBody);
    List<List<GeodeticPoint>> footprint = fov.getFootprint(fovToBody, earth, FastMath.toRadians(0.1));
    Vector3D subSat = earth.projectToGround(state.getPVCoordinates(earth.getBodyFrame()).getPosition(), state.getDate(), earth.getBodyFrame());
    Assert.assertEquals(1, footprint.size());
    List<GeodeticPoint> loop = footprint.get(0);
    Assert.assertEquals(210, loop.size());
    double minEl = Double.POSITIVE_INFINITY;
    double maxEl = 0;
    double minDist = Double.POSITIVE_INFINITY;
    double maxDist = 0;
    for (int i = 0; i < loop.size(); ++i) {
        Assert.assertEquals(0.0, loop.get(i).getAltitude(), 1.0e-15);
        TopocentricFrame topo = new TopocentricFrame(earth, loop.get(i), "atLimb");
        final double elevation = topo.getElevation(state.getPVCoordinates().getPosition(), state.getFrame(), state.getDate());
        minEl = FastMath.min(minEl, elevation);
        maxEl = FastMath.max(maxEl, elevation);
        final double dist = Vector3D.distance(subSat, earth.transform(loop.get(i)));
        minDist = FastMath.min(minDist, dist);
        maxDist = FastMath.max(maxDist, dist);
    }
    Assert.assertEquals(84.6497, FastMath.toDegrees(minEl), 0.001);
    Assert.assertEquals(85.3729, FastMath.toDegrees(maxEl), 0.001);
    Assert.assertEquals(181052.2, minDist, 1.0);
    Assert.assertEquals(209092.8, maxDist, 1.0);
}

Example 5 with NadirPointing

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

the class FieldOfViewTest method testFOVLargerThanEarth.

@Test
public void testFOVLargerThanEarth() throws OrekitException {
    Utils.setDataRoot("regular-data");
    FieldOfView fov = new FieldOfView(Vector3D.PLUS_K, Vector3D.PLUS_I, FastMath.toRadians(45.0), 6, 0.0);
    OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    KeplerianOrbit orbit = new KeplerianOrbit(new PVCoordinates(new Vector3D(7.0e6, 1.0e6, 4.0e6), new Vector3D(-500.0, 8000.0, 1000.0)), FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH, Constants.EIGEN5C_EARTH_MU);
    Propagator propagator = new KeplerianPropagator(orbit);
    propagator.setAttitudeProvider(new NadirPointing(orbit.getFrame(), earth));
    SpacecraftState state = propagator.propagate(orbit.getDate().shiftedBy(1000.0));
    Transform inertToBody = state.getFrame().getTransformTo(earth.getBodyFrame(), state.getDate());
    Transform fovToBody = new Transform(state.getDate(), state.toTransform().getInverse(), inertToBody);
    List<List<GeodeticPoint>> footprint = fov.getFootprint(fovToBody, earth, FastMath.toRadians(1.0));
    Vector3D subSat = earth.projectToGround(state.getPVCoordinates(earth.getBodyFrame()).getPosition(), state.getDate(), earth.getBodyFrame());
    Assert.assertEquals(1, footprint.size());
    List<GeodeticPoint> loop = footprint.get(0);
    Assert.assertEquals(234, loop.size());
    double minEl = Double.POSITIVE_INFINITY;
    double maxEl = 0;
    double minDist = Double.POSITIVE_INFINITY;
    double maxDist = 0;
    for (int i = 0; i < loop.size(); ++i) {
        Assert.assertEquals(0.0, loop.get(i).getAltitude(), 3.0e-7);
        TopocentricFrame topo = new TopocentricFrame(earth, loop.get(i), "atLimb");
        final double elevation = topo.getElevation(state.getPVCoordinates().getPosition(), state.getFrame(), state.getDate());
        minEl = FastMath.min(minEl, elevation);
        maxEl = FastMath.max(maxEl, elevation);
        final double dist = Vector3D.distance(subSat, earth.transform(loop.get(i)));
        minDist = FastMath.min(minDist, dist);
        maxDist = FastMath.max(maxDist, dist);
    }
    Assert.assertEquals(0.0, FastMath.toDegrees(minEl), 2.0e-12);
    Assert.assertEquals(0.0, FastMath.toDegrees(maxEl), 1.7e-12);
    Assert.assertEquals(5323036.6, minDist, 1.0);
    Assert.assertEquals(5347029.8, maxDist, 1.0);
}