Examples with Transform org.orekit.frames.Transform used on opensource projects

Example 56 with Transform

use of org.orekit.frames.Transform in project Orekit by CS-SI.

the class RangeMeasurementCreator method handleStep.

public void handleStep(final SpacecraftState currentState, final boolean isLast) throws OrekitException {
    try {
        for (final GroundStation station : context.stations) {
            final AbsoluteDate date = currentState.getDate();
            final Frame inertial = currentState.getFrame();
            final Vector3D position = currentState.toTransform().getInverse().transformPosition(antennaPhaseCenter);
            if (station.getBaseFrame().getElevation(position, inertial, date) > FastMath.toRadians(30.0)) {
                final UnivariateSolver solver = new BracketingNthOrderBrentSolver(1.0e-12, 5);
                final double downLinkDelay = solver.solve(1000, new UnivariateFunction() {

                    public double value(final double x) throws OrekitExceptionWrapper {
                        try {
                            final Transform t = station.getOffsetToInertial(inertial, date.shiftedBy(x));
                            final double d = Vector3D.distance(position, t.transformPosition(Vector3D.ZERO));
                            return d - x * Constants.SPEED_OF_LIGHT;
                        } catch (OrekitException oe) {
                            throw new OrekitExceptionWrapper(oe);
                        }
                    }
                }, -1.0, 1.0);
                final AbsoluteDate receptionDate = currentState.getDate().shiftedBy(downLinkDelay);
                final Vector3D stationAtReception = station.getOffsetToInertial(inertial, receptionDate).transformPosition(Vector3D.ZERO);
                final double downLinkDistance = Vector3D.distance(position, stationAtReception);
                final double upLinkDelay = solver.solve(1000, new UnivariateFunction() {

                    public double value(final double x) throws OrekitExceptionWrapper {
                        try {
                            final Transform t = station.getOffsetToInertial(inertial, date.shiftedBy(-x));
                            final double d = Vector3D.distance(position, t.transformPosition(Vector3D.ZERO));
                            return d - x * Constants.SPEED_OF_LIGHT;
                        } catch (OrekitException oe) {
                            throw new OrekitExceptionWrapper(oe);
                        }
                    }
                }, -1.0, 1.0);
                final AbsoluteDate emissionDate = currentState.getDate().shiftedBy(-upLinkDelay);
                final Vector3D stationAtEmission = station.getOffsetToInertial(inertial, emissionDate).transformPosition(Vector3D.ZERO);
                final double upLinkDistance = Vector3D.distance(position, stationAtEmission);
                addMeasurement(new Range(station, receptionDate, 0.5 * (downLinkDistance + upLinkDistance), 1.0, 10));
            }
        }
    } catch (OrekitExceptionWrapper oew) {
        throw new OrekitException(oew.getException());
    } catch (OrekitException oe) {
        throw new OrekitException(oe);
    }
}

Example 57 with Transform

use of org.orekit.frames.Transform in project Orekit by CS-SI.

the class RangeRateMeasurementCreator method handleStep.

public void handleStep(final SpacecraftState currentState, final boolean isLast) throws OrekitException {
    for (final GroundStation station : context.stations) {
        final AbsoluteDate date = currentState.getDate();
        final Frame inertial = currentState.getFrame();
        final Vector3D position = currentState.getPVCoordinates().getPosition();
        final Vector3D velocity = currentState.getPVCoordinates().getVelocity();
        if (station.getBaseFrame().getElevation(position, inertial, date) > FastMath.toRadians(30.0)) {
            final UnivariateSolver solver = new BracketingNthOrderBrentSolver(1.0e-12, 5);
            final double downLinkDelay = solver.solve(1000, new UnivariateFunction() {

                public double value(final double x) throws OrekitExceptionWrapper {
                    try {
                        final Transform t = station.getOffsetToInertial(inertial, date.shiftedBy(x));
                        final double d = Vector3D.distance(position, t.transformPosition(Vector3D.ZERO));
                        return d - x * Constants.SPEED_OF_LIGHT;
                    } catch (OrekitException oe) {
                        throw new OrekitExceptionWrapper(oe);
                    }
                }
            }, -1.0, 1.0);
            final AbsoluteDate receptionDate = currentState.getDate().shiftedBy(downLinkDelay);
            final PVCoordinates stationAtReception = station.getOffsetToInertial(inertial, receptionDate).transformPVCoordinates(PVCoordinates.ZERO);
            // line of sight at reception
            final Vector3D receptionLOS = (position.subtract(stationAtReception.getPosition())).normalize();
            // relative velocity, spacecraft-station, at the date of reception
            final Vector3D deltaVr = velocity.subtract(stationAtReception.getVelocity());
            final double upLinkDelay = solver.solve(1000, new UnivariateFunction() {

                public double value(final double x) throws OrekitExceptionWrapper {
                    try {
                        final Transform t = station.getOffsetToInertial(inertial, date.shiftedBy(-x));
                        final double d = Vector3D.distance(position, t.transformPosition(Vector3D.ZERO));
                        return d - x * Constants.SPEED_OF_LIGHT;
                    } catch (OrekitException oe) {
                        throw new OrekitExceptionWrapper(oe);
                    }
                }
            }, -1.0, 1.0);
            final AbsoluteDate emissionDate = currentState.getDate().shiftedBy(-upLinkDelay);
            final PVCoordinates stationAtEmission = station.getOffsetToInertial(inertial, emissionDate).transformPVCoordinates(PVCoordinates.ZERO);
            // line of sight at emission
            final Vector3D emissionLOS = (position.subtract(stationAtEmission.getPosition())).normalize();
            // relative velocity, spacecraft-station, at the date of emission
            final Vector3D deltaVe = velocity.subtract(stationAtEmission.getVelocity());
            // range rate at the date of reception
            final double rr = twoWay ? 0.5 * (deltaVr.dotProduct(receptionLOS) + deltaVe.dotProduct(emissionLOS)) : deltaVr.dotProduct(receptionLOS);
            addMeasurement(new RangeRate(station, date, rr, 1.0, 10, twoWay));
        }
    }
}

Example 58 with Transform

use of org.orekit.frames.Transform in project Orekit by CS-SI.

the class FieldOfViewTest method testNoFootprintInside.

@Test
public void testNoFootprintInside() 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));
    Transform fovToBody = new Transform(AbsoluteDate.J2000_EPOCH, new Vector3D(5e6, 3e6, 2e6));
    try {
        fov.getFootprint(fovToBody, earth, FastMath.toRadians(0.1));
        Assert.fail("an exception should have been thrown");
    } catch (OrekitException oe) {
        Assert.assertEquals(OrekitMessages.POINT_INSIDE_ELLIPSOID, oe.getSpecifier());
    }
}

Example 59 with Transform

use of org.orekit.frames.Transform 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 60 with Transform

use of org.orekit.frames.Transform 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);
}