Search in sources :

Example 1 with ObservedMeasurement

use of org.orekit.estimation.measurements.ObservedMeasurement in project Orekit by CS-SI.

the class HarmonicParametricAccelerationTest method testCoefficientsDetermination.

@Test
public void testCoefficientsDetermination() throws OrekitException {
    final double mass = 2500;
    final Orbit orbit = new CircularOrbit(7500000.0, 1.0e-4, 1.0e-3, 1.7, 0.3, 0.5, PositionAngle.TRUE, FramesFactory.getEME2000(), new AbsoluteDate(new DateComponents(2004, 2, 3), TimeComponents.H00, TimeScalesFactory.getUTC()), Constants.EIGEN5C_EARTH_MU);
    final double period = orbit.getKeplerianPeriod();
    AttitudeProvider maneuverLaw = new LofOffset(orbit.getFrame(), LOFType.VNC);
    SpacecraftState initialState = new SpacecraftState(orbit, maneuverLaw.getAttitude(orbit, orbit.getDate(), orbit.getFrame()), mass);
    double dP = 10.0;
    double minStep = 0.001;
    double maxStep = 100;
    double[][] tolerance = NumericalPropagator.tolerances(dP, orbit, orbit.getType());
    // generate PV measurements corresponding to a tangential maneuver
    AdaptiveStepsizeIntegrator integrator0 = new DormandPrince853Integrator(minStep, maxStep, tolerance[0], tolerance[1]);
    integrator0.setInitialStepSize(60);
    final NumericalPropagator propagator0 = new NumericalPropagator(integrator0);
    propagator0.setInitialState(initialState);
    propagator0.setAttitudeProvider(maneuverLaw);
    ForceModel hpaRefX1 = new HarmonicParametricAcceleration(Vector3D.PLUS_I, true, "refX1", null, period, 1);
    ForceModel hpaRefY1 = new HarmonicParametricAcceleration(Vector3D.PLUS_J, true, "refY1", null, period, 1);
    ForceModel hpaRefZ2 = new HarmonicParametricAcceleration(Vector3D.PLUS_K, true, "refZ2", null, period, 2);
    hpaRefX1.getParametersDrivers()[0].setValue(2.4e-2);
    hpaRefX1.getParametersDrivers()[1].setValue(3.1);
    hpaRefY1.getParametersDrivers()[0].setValue(4.0e-2);
    hpaRefY1.getParametersDrivers()[1].setValue(0.3);
    hpaRefZ2.getParametersDrivers()[0].setValue(1.0e-2);
    hpaRefZ2.getParametersDrivers()[1].setValue(1.8);
    propagator0.addForceModel(hpaRefX1);
    propagator0.addForceModel(hpaRefY1);
    propagator0.addForceModel(hpaRefZ2);
    final List<ObservedMeasurement<?>> measurements = new ArrayList<>();
    propagator0.setMasterMode(10.0, (state, isLast) -> measurements.add(new PV(state.getDate(), state.getPVCoordinates().getPosition(), state.getPVCoordinates().getVelocity(), 1.0e-3, 1.0e-6, 1.0)));
    propagator0.propagate(orbit.getDate().shiftedBy(900));
    // set up an estimator to retrieve the maneuver as several harmonic accelerations in inertial frame
    final NumericalPropagatorBuilder propagatorBuilder = new NumericalPropagatorBuilder(orbit, new DormandPrince853IntegratorBuilder(minStep, maxStep, dP), PositionAngle.TRUE, dP);
    propagatorBuilder.addForceModel(new HarmonicParametricAcceleration(Vector3D.PLUS_I, true, "X1", null, period, 1));
    propagatorBuilder.addForceModel(new HarmonicParametricAcceleration(Vector3D.PLUS_J, true, "Y1", null, period, 1));
    propagatorBuilder.addForceModel(new HarmonicParametricAcceleration(Vector3D.PLUS_K, true, "Z2", null, period, 2));
    final BatchLSEstimator estimator = new BatchLSEstimator(new LevenbergMarquardtOptimizer(), propagatorBuilder);
    estimator.setParametersConvergenceThreshold(1.0e-2);
    estimator.setMaxIterations(20);
    estimator.setMaxEvaluations(100);
    for (final ObservedMeasurement<?> measurement : measurements) {
        estimator.addMeasurement(measurement);
    }
    // we will estimate only the force model parameters, not the orbit
    for (final ParameterDriver d : estimator.getOrbitalParametersDrivers(false).getDrivers()) {
        d.setSelected(false);
    }
    setParameter(estimator, "X1 γ", 1.0e-2);
    setParameter(estimator, "X1 φ", 4.0);
    setParameter(estimator, "Y1 γ", 1.0e-2);
    setParameter(estimator, "Y1 φ", 0.0);
    setParameter(estimator, "Z2 γ", 1.0e-2);
    setParameter(estimator, "Z2 φ", 1.0);
    estimator.estimate();
    Assert.assertTrue(estimator.getIterationsCount() < 15);
    Assert.assertTrue(estimator.getEvaluationsCount() < 15);
    Assert.assertEquals(0.0, estimator.getOptimum().getRMS(), 1.0e-5);
    Assert.assertEquals(hpaRefX1.getParametersDrivers()[0].getValue(), getParameter(estimator, "X1 γ"), 1.e-12);
    Assert.assertEquals(hpaRefX1.getParametersDrivers()[1].getValue(), getParameter(estimator, "X1 φ"), 1.e-12);
    Assert.assertEquals(hpaRefY1.getParametersDrivers()[0].getValue(), getParameter(estimator, "Y1 γ"), 1.e-12);
    Assert.assertEquals(hpaRefY1.getParametersDrivers()[1].getValue(), getParameter(estimator, "Y1 φ"), 1.e-12);
    Assert.assertEquals(hpaRefZ2.getParametersDrivers()[0].getValue(), getParameter(estimator, "Z2 γ"), 1.e-12);
    Assert.assertEquals(hpaRefZ2.getParametersDrivers()[1].getValue(), getParameter(estimator, "Z2 φ"), 1.e-12);
}
Also used : CartesianOrbit(org.orekit.orbits.CartesianOrbit) KeplerianOrbit(org.orekit.orbits.KeplerianOrbit) Orbit(org.orekit.orbits.Orbit) CircularOrbit(org.orekit.orbits.CircularOrbit) PV(org.orekit.estimation.measurements.PV) AdaptiveStepsizeIntegrator(org.hipparchus.ode.nonstiff.AdaptiveStepsizeIntegrator) ArrayList(java.util.ArrayList) DateComponents(org.orekit.time.DateComponents) ParameterDriver(org.orekit.utils.ParameterDriver) FieldAbsoluteDate(org.orekit.time.FieldAbsoluteDate) AbsoluteDate(org.orekit.time.AbsoluteDate) BatchLSEstimator(org.orekit.estimation.leastsquares.BatchLSEstimator) SpacecraftState(org.orekit.propagation.SpacecraftState) FieldSpacecraftState(org.orekit.propagation.FieldSpacecraftState) LevenbergMarquardtOptimizer(org.hipparchus.optim.nonlinear.vector.leastsquares.LevenbergMarquardtOptimizer) CircularOrbit(org.orekit.orbits.CircularOrbit) NumericalPropagator(org.orekit.propagation.numerical.NumericalPropagator) FieldNumericalPropagator(org.orekit.propagation.numerical.FieldNumericalPropagator) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) DormandPrince853IntegratorBuilder(org.orekit.propagation.conversion.DormandPrince853IntegratorBuilder) DormandPrince853Integrator(org.hipparchus.ode.nonstiff.DormandPrince853Integrator) LofOffset(org.orekit.attitudes.LofOffset) AttitudeProvider(org.orekit.attitudes.AttitudeProvider) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) Test(org.junit.Test)

Example 2 with ObservedMeasurement

use of org.orekit.estimation.measurements.ObservedMeasurement in project Orekit by CS-SI.

the class IonoModifierTest method testRangeRateIonoModifier.

@Test
public void testRangeRateIonoModifier() 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);
    // create perfect range measurements
    for (final GroundStation station : context.stations) {
        station.getEastOffsetDriver().setSelected(true);
        station.getNorthOffsetDriver().setSelected(true);
        station.getZenithOffsetDriver().setSelected(true);
    }
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new RangeRateMeasurementCreator(context, false), 1.0, 3.0, 300.0);
    propagator.setSlaveMode();
    final RangeRateIonosphericDelayModifier modifier = new RangeRateIonosphericDelayModifier(model, true);
    for (final ObservedMeasurement<?> measurement : measurements) {
        final AbsoluteDate date = measurement.getDate();
        final SpacecraftState refstate = propagator.propagate(date);
        RangeRate rangeRate = (RangeRate) measurement;
        EstimatedMeasurement<RangeRate> evalNoMod = rangeRate.estimate(0, 0, new SpacecraftState[] { refstate });
        // add modifier
        rangeRate.addModifier(modifier);
        // 
        EstimatedMeasurement<RangeRate> eval = rangeRate.estimate(0, 0, new SpacecraftState[] { refstate });
        final double diffMetersSec = eval.getEstimatedValue()[0] - evalNoMod.getEstimatedValue()[0];
        // TODO: check threshold
        Assert.assertEquals(0.0, diffMetersSec, 0.016);
    }
}
Also used : Context(org.orekit.estimation.Context) GroundStation(org.orekit.estimation.measurements.GroundStation) RangeRateIonosphericDelayModifier(org.orekit.estimation.measurements.modifiers.RangeRateIonosphericDelayModifier) AbsoluteDate(org.orekit.time.AbsoluteDate) SpacecraftState(org.orekit.propagation.SpacecraftState) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) Propagator(org.orekit.propagation.Propagator) RangeRate(org.orekit.estimation.measurements.RangeRate) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) RangeRateMeasurementCreator(org.orekit.estimation.measurements.RangeRateMeasurementCreator) Test(org.junit.Test)

Example 3 with ObservedMeasurement

use of org.orekit.estimation.measurements.ObservedMeasurement in project Orekit by CS-SI.

the class IonoModifierTest method testTurnAroundRangeIonoModifier.

@Test
public void testTurnAroundRangeIonoModifier() 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);
    // Create perfect turn-around measurements
    for (Map.Entry<GroundStation, GroundStation> entry : context.TARstations.entrySet()) {
        final GroundStation masterStation = entry.getKey();
        final GroundStation slaveStation = entry.getValue();
        masterStation.getEastOffsetDriver().setSelected(true);
        masterStation.getNorthOffsetDriver().setSelected(true);
        masterStation.getZenithOffsetDriver().setSelected(true);
        slaveStation.getEastOffsetDriver().setSelected(true);
        slaveStation.getNorthOffsetDriver().setSelected(true);
        slaveStation.getZenithOffsetDriver().setSelected(true);
    }
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new TurnAroundRangeMeasurementCreator(context), 1.0, 3.0, 300.0);
    propagator.setSlaveMode();
    final TurnAroundRangeIonosphericDelayModifier modifier = new TurnAroundRangeIonosphericDelayModifier(model);
    for (final ObservedMeasurement<?> measurement : measurements) {
        final AbsoluteDate date = measurement.getDate();
        final SpacecraftState refstate = propagator.propagate(date);
        TurnAroundRange turnAroundRange = (TurnAroundRange) measurement;
        EstimatedMeasurement<TurnAroundRange> evalNoMod = turnAroundRange.estimate(12, 17, new SpacecraftState[] { refstate });
        Assert.assertEquals(12, evalNoMod.getIteration());
        Assert.assertEquals(17, evalNoMod.getCount());
        // Add modifier
        turnAroundRange.addModifier(modifier);
        boolean found = false;
        for (final EstimationModifier<TurnAroundRange> existing : turnAroundRange.getModifiers()) {
            found = found || existing == modifier;
        }
        Assert.assertTrue(found);
        // 
        EstimatedMeasurement<TurnAroundRange> eval = turnAroundRange.estimate(12, 17, new SpacecraftState[] { refstate });
        Assert.assertEquals(evalNoMod.getStatus(), eval.getStatus());
        eval.setStatus(EstimatedMeasurement.Status.REJECTED);
        Assert.assertEquals(EstimatedMeasurement.Status.REJECTED, eval.getStatus());
        eval.setStatus(evalNoMod.getStatus());
        try {
            eval.getParameterDerivatives(new ParameterDriver("extra", 0, 1, -1, +1));
            Assert.fail("an exception should have been thrown");
        } catch (OrekitIllegalArgumentException oiae) {
            Assert.assertEquals(OrekitMessages.UNSUPPORTED_PARAMETER_NAME, oiae.getSpecifier());
        }
        final double diffMeters = eval.getEstimatedValue()[0] - evalNoMod.getEstimatedValue()[0];
        // TODO: check threshold
        Assert.assertEquals(0.0, diffMeters, 30.0);
    }
}
Also used : Context(org.orekit.estimation.Context) GroundStation(org.orekit.estimation.measurements.GroundStation) TurnAroundRangeIonosphericDelayModifier(org.orekit.estimation.measurements.modifiers.TurnAroundRangeIonosphericDelayModifier) ParameterDriver(org.orekit.utils.ParameterDriver) AbsoluteDate(org.orekit.time.AbsoluteDate) OrekitIllegalArgumentException(org.orekit.errors.OrekitIllegalArgumentException) SpacecraftState(org.orekit.propagation.SpacecraftState) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) Propagator(org.orekit.propagation.Propagator) TurnAroundRange(org.orekit.estimation.measurements.TurnAroundRange) Map(java.util.Map) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) TurnAroundRangeMeasurementCreator(org.orekit.estimation.measurements.TurnAroundRangeMeasurementCreator) Test(org.junit.Test)

Example 4 with ObservedMeasurement

use of org.orekit.estimation.measurements.ObservedMeasurement in project Orekit by CS-SI.

the class IonoModifierTest method testAngularIonoModifier.

@Test
public void testAngularIonoModifier() 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);
    // create perfect range measurements
    for (final GroundStation station : context.stations) {
        station.getEastOffsetDriver().setSelected(true);
        station.getNorthOffsetDriver().setSelected(true);
        station.getZenithOffsetDriver().setSelected(true);
    }
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new AngularAzElMeasurementCreator(context), 1.0, 3.0, 300.0);
    propagator.setSlaveMode();
    final AngularIonosphericDelayModifier modifier = new AngularIonosphericDelayModifier(model);
    for (final ObservedMeasurement<?> measurement : measurements) {
        final AbsoluteDate date = measurement.getDate();
        final SpacecraftState refstate = propagator.propagate(date);
        AngularAzEl angular = (AngularAzEl) measurement;
        EstimatedMeasurement<AngularAzEl> evalNoMod = angular.estimate(0, 0, new SpacecraftState[] { refstate });
        // add modifier
        angular.addModifier(modifier);
        // 
        EstimatedMeasurement<AngularAzEl> eval = angular.estimate(0, 0, new SpacecraftState[] { refstate });
        final double diffAz = MathUtils.normalizeAngle(eval.getEstimatedValue()[0], evalNoMod.getEstimatedValue()[0]) - evalNoMod.getEstimatedValue()[0];
        final double diffEl = MathUtils.normalizeAngle(eval.getEstimatedValue()[1], evalNoMod.getEstimatedValue()[1]) - evalNoMod.getEstimatedValue()[1];
        // TODO: check threshold
        Assert.assertEquals(0.0, diffAz, 5.0e-5);
        Assert.assertEquals(0.0, diffEl, 5.0e-6);
    }
}
Also used : Context(org.orekit.estimation.Context) GroundStation(org.orekit.estimation.measurements.GroundStation) AngularIonosphericDelayModifier(org.orekit.estimation.measurements.modifiers.AngularIonosphericDelayModifier) AbsoluteDate(org.orekit.time.AbsoluteDate) SpacecraftState(org.orekit.propagation.SpacecraftState) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) Propagator(org.orekit.propagation.Propagator) AngularAzElMeasurementCreator(org.orekit.estimation.measurements.AngularAzElMeasurementCreator) AngularAzEl(org.orekit.estimation.measurements.AngularAzEl) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) Test(org.junit.Test)

Example 5 with ObservedMeasurement

use of org.orekit.estimation.measurements.ObservedMeasurement in project Orekit by CS-SI.

the class OnBoardAntennaInterSatellitesRangeModifierTest method testPreliminary.

@Test
public void testPreliminary() throws OrekitException {
    // this test does not check OnBoardAntennaInterSatellitesRangeModifier at all,
    // it just checks InterSatellitesRangeMeasurementCreator behaves as necessary for the other test
    // the *real* test is testEffect below
    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 double xOffset1 = -2.5;
    final double yOffset2 = 0.8;
    final Propagator p2 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> antennaCenteredMeasurements = EstimationTestUtils.createMeasurements(p2, new InterSatellitesRangeMeasurementCreator(ephemeris, new Vector3D(xOffset1, 0, 0), new Vector3D(0, yOffset2, 0)), 1.0, 3.0, 300.0);
    for (int i = 0; i < spacecraftCenteredMeasurements.size(); ++i) {
        InterSatellitesRange sr = (InterSatellitesRange) spacecraftCenteredMeasurements.get(i);
        InterSatellitesRange ar = (InterSatellitesRange) antennaCenteredMeasurements.get(i);
        Assert.assertEquals(0.0, sr.getDate().durationFrom(ar.getDate()), 2.0e-8);
        Assert.assertTrue(ar.getObservedValue()[0] - sr.getObservedValue()[0] >= -1.0);
        Assert.assertTrue(ar.getObservedValue()[0] - sr.getObservedValue()[0] <= -0.36);
    }
}
Also used : Context(org.orekit.estimation.Context) CartesianOrbit(org.orekit.orbits.CartesianOrbit) CartesianOrbit(org.orekit.orbits.CartesianOrbit) Orbit(org.orekit.orbits.Orbit) TimeStampedPVCoordinates(org.orekit.utils.TimeStampedPVCoordinates) InterSatellitesRange(org.orekit.estimation.measurements.InterSatellitesRange) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) BoundedPropagator(org.orekit.propagation.BoundedPropagator) Propagator(org.orekit.propagation.Propagator) InterSatellitesRangeMeasurementCreator(org.orekit.estimation.measurements.InterSatellitesRangeMeasurementCreator) LofOffset(org.orekit.attitudes.LofOffset) BoundedPropagator(org.orekit.propagation.BoundedPropagator) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) Test(org.junit.Test)

Aggregations

ObservedMeasurement (org.orekit.estimation.measurements.ObservedMeasurement)49 NumericalPropagatorBuilder (org.orekit.propagation.conversion.NumericalPropagatorBuilder)44 Test (org.junit.Test)41 Context (org.orekit.estimation.Context)40 Propagator (org.orekit.propagation.Propagator)40 Orbit (org.orekit.orbits.Orbit)20 AbsoluteDate (org.orekit.time.AbsoluteDate)19 ParameterDriversList (org.orekit.utils.ParameterDriversList)19 RangeMeasurementCreator (org.orekit.estimation.measurements.RangeMeasurementCreator)17 Vector3D (org.hipparchus.geometry.euclidean.threed.Vector3D)16 ParameterDriver (org.orekit.utils.ParameterDriver)15 Range (org.orekit.estimation.measurements.Range)14 KeplerianOrbit (org.orekit.orbits.KeplerianOrbit)13 RealMatrix (org.hipparchus.linear.RealMatrix)12 ArrayList (java.util.ArrayList)11 LevenbergMarquardtOptimizer (org.hipparchus.optim.nonlinear.vector.leastsquares.LevenbergMarquardtOptimizer)11 CartesianOrbit (org.orekit.orbits.CartesianOrbit)11 BoundedPropagator (org.orekit.propagation.BoundedPropagator)11 SpacecraftState (org.orekit.propagation.SpacecraftState)11 GroundStation (org.orekit.estimation.measurements.GroundStation)10