Examples with BoundedPropagator org.orekit.propagation.BoundedPropagator used on opensource projects

Example 31 with BoundedPropagator

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

the class EphemerisSegmentPropagatorTest method testPropagator.

/**
 * Check {@link EphemerisSegmentPropagator} and {@link EphemerisSegment#getPropagator()}.
 *
 * @throws Exception on error.
 */
@Test
public void testPropagator() throws Exception {
    // setup
    AbsoluteDate start = AbsoluteDate.J2000_EPOCH, end = start.shiftedBy(60);
    Frame frame = FramesFactory.getEME2000();
    List<TimeStampedPVCoordinates> coordinates = Arrays.asList(new TimeStampedPVCoordinates(start, new Vector3D(6778137, 0, 0), new Vector3D(0, 7.5e3, 0)), new TimeStampedPVCoordinates(start.shiftedBy(30), new Vector3D(6778137 + 1, 0, 0), new Vector3D(0, 7.5e3, 0)), new TimeStampedPVCoordinates(end, new Vector3D(6778137 + 3, 0, 0), new Vector3D(0, 7.5e3, 0)));
    EphemerisSegment ephemeris = new EphemerisSegment() {

        @Override
        public double getMu() {
            return Constants.EGM96_EARTH_MU;
        }

        @Override
        public String getFrameCenterString() {
            return null;
        }

        @Override
        public String getFrameString() {
            return null;
        }

        @Override
        public Frame getFrame() throws OrekitException {
            return frame;
        }

        @Override
        public String getTimeScaleString() {
            return null;
        }

        @Override
        public TimeScale getTimeScale() throws OrekitException {
            return null;
        }

        @Override
        public int getInterpolationSamples() {
            return 2;
        }

        @Override
        public CartesianDerivativesFilter getAvailableDerivatives() {
            return CartesianDerivativesFilter.USE_P;
        }

        @Override
        public List<TimeStampedPVCoordinates> getCoordinates() {
            return coordinates;
        }

        @Override
        public AbsoluteDate getStart() {
            return start;
        }

        @Override
        public AbsoluteDate getStop() {
            return end;
        }
    };
    // action
    BoundedPropagator propagator = ephemeris.getPropagator();
    // verify
    Assert.assertThat(propagator.getMinDate(), CoreMatchers.is(start));
    Assert.assertThat(propagator.getMaxDate(), CoreMatchers.is(end));
    Assert.assertThat(propagator.getFrame(), CoreMatchers.is(frame));
    int ulps = 0;
    PVCoordinates expected = new PVCoordinates(new Vector3D(6778137, 0, 0), new Vector3D(1.0 / 30, 0, 0));
    Assert.assertThat(propagator.propagate(start).getPVCoordinates(), OrekitMatchers.pvCloseTo(expected, ulps));
    Assert.assertThat(propagator.getPVCoordinates(start, frame), OrekitMatchers.pvCloseTo(expected, ulps));
    expected = new PVCoordinates(new Vector3D(6778137 + 2, 0, 0), new Vector3D(2 / 30.0, 0, 0));
    Assert.assertThat(propagator.propagate(start.shiftedBy(45)).getPVCoordinates(), OrekitMatchers.pvCloseTo(expected, ulps));
    Assert.assertThat(propagator.getPVCoordinates(start.shiftedBy(45), frame), OrekitMatchers.pvCloseTo(expected, ulps));
    expected = new PVCoordinates(new Vector3D(6778137 + 3, 0, 0), new Vector3D(2 / 30.0, 0, 0));
    Assert.assertThat(propagator.propagate(end).getPVCoordinates(), OrekitMatchers.pvCloseTo(expected, ulps));
    Assert.assertThat(propagator.getPVCoordinates(end, frame), OrekitMatchers.pvCloseTo(expected, ulps));
    // check reset state is prohibited
    SpacecraftState ic = propagator.propagate(start);
    try {
        propagator.resetInitialState(ic);
        Assert.fail("Expected Exception");
    } catch (OrekitException e) {
    // expected
    }
}

Example 32 with BoundedPropagator

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

the class OnBoardAntennaInterSatellitesRangeModifierTest method testEffect.

@Test
public void testEffect() throws OrekitException {
    Context context = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
    final NumericalPropagatorBuilder propagatorBuilder = context.createBuilder(OrbitType.KEPLERIAN, PositionAngle.TRUE, true, 1.0e-6, 60.0, 0.001);
    propagatorBuilder.setAttitudeProvider(new LofOffset(propagatorBuilder.getFrame(), LOFType.LVLH));
    // create perfect inter-satellites range measurements without antenna offset
    final TimeStampedPVCoordinates original = context.initialOrbit.getPVCoordinates();
    final Orbit closeOrbit = new CartesianOrbit(new TimeStampedPVCoordinates(context.initialOrbit.getDate(), original.getPosition().add(new Vector3D(1000, 2000, 3000)), original.getVelocity().add(new Vector3D(-0.03, 0.01, 0.02))), context.initialOrbit.getFrame(), context.initialOrbit.getMu());
    final Propagator closePropagator = EstimationTestUtils.createPropagator(closeOrbit, propagatorBuilder);
    closePropagator.setEphemerisMode();
    closePropagator.propagate(context.initialOrbit.getDate().shiftedBy(3.5 * closeOrbit.getKeplerianPeriod()));
    final BoundedPropagator ephemeris = closePropagator.getGeneratedEphemeris();
    final Propagator p1 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> spacecraftCenteredMeasurements = EstimationTestUtils.createMeasurements(p1, new InterSatellitesRangeMeasurementCreator(ephemeris, Vector3D.ZERO, Vector3D.ZERO), 1.0, 3.0, 300.0);
    // create perfect inter-satellites range measurements with antenna offset
    final Vector3D apc1 = new Vector3D(-2.5, 0.0, 0);
    final Vector3D apc2 = new Vector3D(0.0, 0.8, 0);
    final Propagator p2 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> antennaCenteredMeasurements = EstimationTestUtils.createMeasurements(p2, new InterSatellitesRangeMeasurementCreator(ephemeris, apc1, apc2), 1.0, 3.0, 300.0);
    final Propagator p3 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    OnBoardAntennaInterSatellitesRangeModifier modifier = new OnBoardAntennaInterSatellitesRangeModifier(apc1, apc2);
    for (int i = 0; i < spacecraftCenteredMeasurements.size(); ++i) {
        InterSatellitesRange sr = (InterSatellitesRange) spacecraftCenteredMeasurements.get(i);
        sr.addModifier(modifier);
        EstimatedMeasurement<InterSatellitesRange> estimated = sr.estimate(0, 0, new SpacecraftState[] { p3.propagate(sr.getDate()), ephemeris.propagate(sr.getDate()) });
        InterSatellitesRange ar = (InterSatellitesRange) antennaCenteredMeasurements.get(i);
        Assert.assertEquals(0.0, sr.getDate().durationFrom(ar.getDate()), 2.0e-8);
        Assert.assertEquals(ar.getObservedValue()[0], estimated.getEstimatedValue()[0], 2.0e-5);
    }
}

Example 33 with BoundedPropagator

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

the class NumericalPropagatorTest method testEphemerisDatesBackward.

@Test
public void testEphemerisDatesBackward() throws OrekitException {
    // setup
    TimeScale tai = TimeScalesFactory.getTAI();
    AbsoluteDate initialDate = new AbsoluteDate("2015-07-05", tai);
    AbsoluteDate startDate = new AbsoluteDate("2015-07-03", tai).shiftedBy(-0.1);
    AbsoluteDate endDate = new AbsoluteDate("2015-07-04", tai);
    Frame eci = FramesFactory.getGCRF();
    KeplerianOrbit orbit = new KeplerianOrbit(600e3 + Constants.WGS84_EARTH_EQUATORIAL_RADIUS, 0, 0, 0, 0, 0, PositionAngle.TRUE, eci, initialDate, mu);
    OrbitType type = OrbitType.CARTESIAN;
    double[][] tol = NumericalPropagator.tolerances(1e-3, orbit, type);
    NumericalPropagator prop = new NumericalPropagator(new DormandPrince853Integrator(0.1, 500, tol[0], tol[1]));
    prop.setOrbitType(type);
    prop.resetInitialState(new SpacecraftState(new CartesianOrbit(orbit)));
    // action
    prop.setEphemerisMode();
    prop.propagate(endDate, startDate);
    BoundedPropagator ephemeris = prop.getGeneratedEphemeris();
    // verify
    TimeStampedPVCoordinates actualPV = ephemeris.getPVCoordinates(startDate, eci);
    TimeStampedPVCoordinates expectedPV = orbit.getPVCoordinates(startDate, eci);
    MatcherAssert.assertThat(actualPV.getPosition(), OrekitMatchers.vectorCloseTo(expectedPV.getPosition(), 1.0));
    MatcherAssert.assertThat(actualPV.getVelocity(), OrekitMatchers.vectorCloseTo(expectedPV.getVelocity(), 1.0));
    MatcherAssert.assertThat(ephemeris.getMinDate().durationFrom(startDate), OrekitMatchers.closeTo(0, 0));
    MatcherAssert.assertThat(ephemeris.getMaxDate().durationFrom(endDate), OrekitMatchers.closeTo(0, 0));
    // test date
    AbsoluteDate date = endDate.shiftedBy(-0.11);
    Assert.assertEquals(ephemeris.propagate(date).getDate().durationFrom(date), 0, 0);
}

Example 34 with BoundedPropagator

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

the class NumericalPropagatorTest method testEphemerisAdditionalState.

@Test
public void testEphemerisAdditionalState() throws OrekitException, IOException {
    // Propagation of the initial at t + dt
    final double dt = -3200;
    final double rate = 2.0;
    propagator.addAdditionalStateProvider(new AdditionalStateProvider() {

        public String getName() {
            return "squaredA";
        }

        public double[] getAdditionalState(SpacecraftState state) {
            return new double[] { state.getA() * state.getA() };
        }
    });
    propagator.addAdditionalEquations(new AdditionalEquations() {

        public String getName() {
            return "extra";
        }

        public double[] computeDerivatives(SpacecraftState s, double[] pDot) {
            pDot[0] = rate;
            return null;
        }
    });
    propagator.setInitialState(propagator.getInitialState().addAdditionalState("extra", 1.5));
    propagator.setOrbitType(OrbitType.CARTESIAN);
    propagator.setEphemerisMode();
    propagator.propagate(initDate.shiftedBy(dt));
    final BoundedPropagator ephemeris1 = propagator.getGeneratedEphemeris();
    Assert.assertEquals(initDate.shiftedBy(dt), ephemeris1.getMinDate());
    Assert.assertEquals(initDate, ephemeris1.getMaxDate());
    try {
        ephemeris1.propagate(ephemeris1.getMinDate().shiftedBy(-10.0));
        Assert.fail("an exception should have been thrown");
    } catch (OrekitException pe) {
        Assert.assertEquals(OrekitMessages.OUT_OF_RANGE_EPHEMERIDES_DATE, pe.getSpecifier());
    }
    try {
        ephemeris1.propagate(ephemeris1.getMaxDate().shiftedBy(+10.0));
        Assert.fail("an exception should have been thrown");
    } catch (OrekitException pe) {
        Assert.assertEquals(OrekitMessages.OUT_OF_RANGE_EPHEMERIDES_DATE, pe.getSpecifier());
    }
    double shift = -60;
    SpacecraftState s = ephemeris1.propagate(initDate.shiftedBy(shift));
    Assert.assertEquals(2, s.getAdditionalStates().size());
    Assert.assertTrue(s.hasAdditionalState("squaredA"));
    Assert.assertTrue(s.hasAdditionalState("extra"));
    Assert.assertEquals(s.getA() * s.getA(), s.getAdditionalState("squaredA")[0], 1.0e-10);
    Assert.assertEquals(1.5 + shift * rate, s.getAdditionalState("extra")[0], 1.0e-10);
    try {
        ephemeris1.resetInitialState(s);
        Assert.fail("an exception should have been thrown");
    } catch (OrekitException oe) {
        Assert.assertEquals(OrekitMessages.NON_RESETABLE_STATE, oe.getSpecifier());
    }
}

Example 35 with BoundedPropagator

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

the class IntegratedEphemerisTest method testPartialDerivativesIssue16.

@Test
public void testPartialDerivativesIssue16() throws OrekitException {
    final String eqName = "derivatives";
    numericalPropagator.setEphemerisMode();
    numericalPropagator.setOrbitType(OrbitType.CARTESIAN);
    final PartialDerivativesEquations derivatives = new PartialDerivativesEquations(eqName, numericalPropagator);
    final SpacecraftState initialState = derivatives.setInitialJacobians(new SpacecraftState(initialOrbit));
    final JacobiansMapper mapper = derivatives.getMapper();
    numericalPropagator.setInitialState(initialState);
    numericalPropagator.propagate(initialOrbit.getDate().shiftedBy(3600.0));
    BoundedPropagator ephemeris = numericalPropagator.getGeneratedEphemeris();
    ephemeris.setMasterMode(new OrekitStepHandler() {

        private final Array2DRowRealMatrix dYdY0 = new Array2DRowRealMatrix(6, 6);

        public void handleStep(OrekitStepInterpolator interpolator, boolean isLast) throws OrekitException {
            SpacecraftState state = interpolator.getCurrentState();
            Assert.assertEquals(mapper.getAdditionalStateDimension(), state.getAdditionalState(eqName).length);
            mapper.getStateJacobian(state, dYdY0.getDataRef());
            // no parameters, this is a no-op and should work
            mapper.getParametersJacobian(state, null);
            RealMatrix deltaId = dYdY0.subtract(MatrixUtils.createRealIdentityMatrix(6));
            Assert.assertTrue(deltaId.getNorm() > 100);
            Assert.assertTrue(deltaId.getNorm() < 3100);
        }
    });
    ephemeris.propagate(initialOrbit.getDate().shiftedBy(1800.0));
}