Search in sources :

Example 46 with ObservedMeasurement

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

the class EstimationTestUtils method createMeasurements.

public static List<ObservedMeasurement<?>> createMeasurements(final Propagator propagator, final MeasurementCreator creator, final double startPeriod, final double endPeriod, final double step) throws OrekitException {
    propagator.setMasterMode(step, creator);
    final double period = propagator.getInitialState().getKeplerianPeriod();
    final AbsoluteDate start = propagator.getInitialState().getDate().shiftedBy(startPeriod * period);
    final AbsoluteDate end = propagator.getInitialState().getDate().shiftedBy(endPeriod * period);
    propagator.propagate(start, end);
    final List<ObservedMeasurement<?>> measurements = creator.getMeasurements();
    for (final ObservedMeasurement<?> measurement : measurements) {
        for (final ParameterDriver driver : measurement.getParametersDrivers()) {
            if (driver.getReferenceDate() == null) {
                driver.setReferenceDate(propagator.getInitialState().getDate());
            }
        }
    }
    return measurements;
}
Also used : ParameterDriver(org.orekit.utils.ParameterDriver) FieldAbsoluteDate(org.orekit.time.FieldAbsoluteDate) AbsoluteDate(org.orekit.time.AbsoluteDate) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement)

Example 47 with ObservedMeasurement

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

the class IodLambertTest method testLambert.

@Test
public void testLambert() throws OrekitException {
    final Context context = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
    final double mu = context.initialOrbit.getMu();
    final Frame frame = context.initialOrbit.getFrame();
    final NumericalPropagatorBuilder propagatorBuilder = context.createBuilder(OrbitType.KEPLERIAN, PositionAngle.TRUE, true, 1.0e-6, 60.0, 0.001);
    // create perfect range measurements
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new PVMeasurementCreator(), 0.0, 1.0, 60.0);
    // measurement data 1
    final int idMeasure1 = 0;
    final AbsoluteDate date1 = measurements.get(idMeasure1).getDate();
    /*final Vector3D stapos1 = context.stations.get(0)  // FIXME we need to access the station of the measurement
                                    .getBaseFrame()
                                    .getPVCoordinates(date1, frame)
                                    .getPosition();*/
    final Vector3D position1 = new Vector3D(measurements.get(idMeasure1).getObservedValue()[0], measurements.get(idMeasure1).getObservedValue()[1], measurements.get(idMeasure1).getObservedValue()[2]);
    // measurement data 2
    final int idMeasure2 = 10;
    final AbsoluteDate date2 = measurements.get(idMeasure2).getDate();
    /*final Vector3D stapos2 = context.stations.get(0)  // FIXME we need to access the station of the measurement
                        .getBaseFrame()
                        .getPVCoordinates(date2, frame)
                        .getPosition();*/
    final Vector3D position2 = new Vector3D(measurements.get(idMeasure2).getObservedValue()[0], measurements.get(idMeasure2).getObservedValue()[1], measurements.get(idMeasure2).getObservedValue()[2]);
    final int nRev = 0;
    // instantiate the IOD method
    final IodLambert iod = new IodLambert(mu);
    final KeplerianOrbit orbit = iod.estimate(frame, true, nRev, /*stapos1.add*/
    (position1), date1, /*stapos2.add*/
    (position2), date2);
    Assert.assertEquals(orbit.getA(), context.initialOrbit.getA(), 1.0e-9 * context.initialOrbit.getA());
    Assert.assertEquals(orbit.getE(), context.initialOrbit.getE(), 1.0e-9 * context.initialOrbit.getE());
    Assert.assertEquals(orbit.getI(), context.initialOrbit.getI(), 1.0e-9 * context.initialOrbit.getI());
}
Also used : Context(org.orekit.estimation.Context) Frame(org.orekit.frames.Frame) AbsoluteDate(org.orekit.time.AbsoluteDate) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) TLEPropagator(org.orekit.propagation.analytical.tle.TLEPropagator) Propagator(org.orekit.propagation.Propagator) KeplerianOrbit(org.orekit.orbits.KeplerianOrbit) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) PVMeasurementCreator(org.orekit.estimation.measurements.PVMeasurementCreator) Test(org.junit.Test)

Example 48 with ObservedMeasurement

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

the class BatchLSEstimatorTest method testMultiSat.

@Test
public void testMultiSat() throws OrekitException {
    Context context = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
    final NumericalPropagatorBuilder propagatorBuilder1 = context.createBuilder(OrbitType.KEPLERIAN, PositionAngle.TRUE, true, 1.0e-6, 60.0, 1.0);
    final NumericalPropagatorBuilder propagatorBuilder2 = context.createBuilder(OrbitType.KEPLERIAN, PositionAngle.TRUE, true, 1.0e-6, 60.0, 1.0);
    // Create perfect inter-satellites range measurements
    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, propagatorBuilder2);
    closePropagator.setEphemerisMode();
    closePropagator.propagate(context.initialOrbit.getDate().shiftedBy(3.5 * closeOrbit.getKeplerianPeriod()));
    final BoundedPropagator ephemeris = closePropagator.getGeneratedEphemeris();
    Propagator propagator1 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder1);
    final List<ObservedMeasurement<?>> r12 = EstimationTestUtils.createMeasurements(propagator1, new InterSatellitesRangeMeasurementCreator(ephemeris), 1.0, 3.0, 300.0);
    // create perfect range measurements for first satellite
    propagator1 = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder1);
    final List<ObservedMeasurement<?>> r1 = EstimationTestUtils.createMeasurements(propagator1, new RangeMeasurementCreator(context), 1.0, 3.0, 300.0);
    // create orbit estimator
    final BatchLSEstimator estimator = new BatchLSEstimator(new LevenbergMarquardtOptimizer(), propagatorBuilder1, propagatorBuilder2);
    for (final ObservedMeasurement<?> interSat : r12) {
        estimator.addMeasurement(interSat);
    }
    for (final ObservedMeasurement<?> range : r1) {
        estimator.addMeasurement(range);
    }
    estimator.setParametersConvergenceThreshold(1.0e-2);
    estimator.setMaxIterations(10);
    estimator.setMaxEvaluations(20);
    estimator.setObserver(new BatchLSObserver() {

        int lastIter = 0;

        int lastEval = 0;

        /**
         * {@inheritDoc}
         */
        @Override
        public void evaluationPerformed(int iterationsCount, int evaluationscount, Orbit[] orbits, ParameterDriversList estimatedOrbitalParameters, ParameterDriversList estimatedPropagatorParameters, ParameterDriversList estimatedMeasurementsParameters, EstimationsProvider evaluationsProvider, Evaluation lspEvaluation) throws OrekitException {
            if (iterationsCount == lastIter) {
                Assert.assertEquals(lastEval + 1, evaluationscount);
            } else {
                Assert.assertEquals(lastIter + 1, iterationsCount);
            }
            lastIter = iterationsCount;
            lastEval = evaluationscount;
            Assert.assertEquals(r12.size() + r1.size(), evaluationsProvider.getNumber());
            try {
                evaluationsProvider.getEstimatedMeasurement(-1);
                Assert.fail("an exception should have been thrown");
            } catch (OrekitException oe) {
                Assert.assertEquals(LocalizedCoreFormats.OUT_OF_RANGE_SIMPLE, oe.getSpecifier());
            }
            try {
                evaluationsProvider.getEstimatedMeasurement(r12.size() + r1.size());
                Assert.fail("an exception should have been thrown");
            } catch (OrekitException oe) {
                Assert.assertEquals(LocalizedCoreFormats.OUT_OF_RANGE_SIMPLE, oe.getSpecifier());
            }
            AbsoluteDate previous = AbsoluteDate.PAST_INFINITY;
            for (int i = 0; i < evaluationsProvider.getNumber(); ++i) {
                AbsoluteDate current = evaluationsProvider.getEstimatedMeasurement(i).getDate();
                Assert.assertTrue(current.compareTo(previous) >= 0);
                previous = current;
            }
        }
    });
    List<DelegatingDriver> parameters = estimator.getOrbitalParametersDrivers(true).getDrivers();
    ParameterDriver a0Driver = parameters.get(0);
    Assert.assertEquals("a[0]", a0Driver.getName());
    a0Driver.setValue(a0Driver.getValue() + 1.2);
    a0Driver.setReferenceDate(AbsoluteDate.GALILEO_EPOCH);
    ParameterDriver a1Driver = parameters.get(6);
    Assert.assertEquals("a[1]", a1Driver.getName());
    a1Driver.setValue(a1Driver.getValue() - 5.4);
    a1Driver.setReferenceDate(AbsoluteDate.GALILEO_EPOCH);
    final Orbit before = new KeplerianOrbit(parameters.get(6).getValue(), parameters.get(7).getValue(), parameters.get(8).getValue(), parameters.get(9).getValue(), parameters.get(10).getValue(), parameters.get(11).getValue(), PositionAngle.TRUE, closeOrbit.getFrame(), closeOrbit.getDate(), closeOrbit.getMu());
    Assert.assertEquals(4.7246, Vector3D.distance(closeOrbit.getPVCoordinates().getPosition(), before.getPVCoordinates().getPosition()), 1.0e-3);
    Assert.assertEquals(0.0010514, Vector3D.distance(closeOrbit.getPVCoordinates().getVelocity(), before.getPVCoordinates().getVelocity()), 1.0e-6);
    EstimationTestUtils.checkFit(context, estimator, 2, 3, 0.0, 2.3e-06, 0.0, 6.6e-06, 0.0, 6.2e-07, 0.0, 2.8e-10);
    final Orbit determined = new KeplerianOrbit(parameters.get(6).getValue(), parameters.get(7).getValue(), parameters.get(8).getValue(), parameters.get(9).getValue(), parameters.get(10).getValue(), parameters.get(11).getValue(), PositionAngle.TRUE, closeOrbit.getFrame(), closeOrbit.getDate(), closeOrbit.getMu());
    Assert.assertEquals(0.0, Vector3D.distance(closeOrbit.getPVCoordinates().getPosition(), determined.getPVCoordinates().getPosition()), 1.6e-6);
    Assert.assertEquals(0.0, Vector3D.distance(closeOrbit.getPVCoordinates().getVelocity(), determined.getPVCoordinates().getVelocity()), 1.6e-9);
    // got a default one
    for (final ParameterDriver driver : estimator.getOrbitalParametersDrivers(true).getDrivers()) {
        if (driver.getName().startsWith("a[")) {
            // user-specified reference date
            Assert.assertEquals(0, driver.getReferenceDate().durationFrom(AbsoluteDate.GALILEO_EPOCH), 1.0e-15);
        } else {
            // default reference date
            Assert.assertEquals(0, driver.getReferenceDate().durationFrom(propagatorBuilder1.getInitialOrbitDate()), 1.0e-15);
        }
    }
}
Also used : CartesianOrbit(org.orekit.orbits.CartesianOrbit) TimeStampedPVCoordinates(org.orekit.utils.TimeStampedPVCoordinates) AbsoluteDate(org.orekit.time.AbsoluteDate) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) ParameterDriversList(org.orekit.utils.ParameterDriversList) BoundedPropagator(org.orekit.propagation.BoundedPropagator) Propagator(org.orekit.propagation.Propagator) OrekitException(org.orekit.errors.OrekitException) KeplerianOrbit(org.orekit.orbits.KeplerianOrbit) DelegatingDriver(org.orekit.utils.ParameterDriversList.DelegatingDriver) BoundedPropagator(org.orekit.propagation.BoundedPropagator) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) EstimationsProvider(org.orekit.estimation.measurements.EstimationsProvider) Context(org.orekit.estimation.Context) Evaluation(org.hipparchus.optim.nonlinear.vector.leastsquares.LeastSquaresProblem.Evaluation) Orbit(org.orekit.orbits.Orbit) CartesianOrbit(org.orekit.orbits.CartesianOrbit) KeplerianOrbit(org.orekit.orbits.KeplerianOrbit) ParameterDriver(org.orekit.utils.ParameterDriver) LevenbergMarquardtOptimizer(org.hipparchus.optim.nonlinear.vector.leastsquares.LevenbergMarquardtOptimizer) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) InterSatellitesRangeMeasurementCreator(org.orekit.estimation.measurements.InterSatellitesRangeMeasurementCreator) RangeMeasurementCreator(org.orekit.estimation.measurements.RangeMeasurementCreator) InterSatellitesRangeMeasurementCreator(org.orekit.estimation.measurements.InterSatellitesRangeMeasurementCreator) Test(org.junit.Test)

Example 49 with ObservedMeasurement

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

the class BatchLSEstimatorTest method testKeplerRangeWithOnBoardAntennaOffset.

/**
 * Perfect range measurements with a biased start and an on-board antenna range offset
 * @throws OrekitException
 */
@Test
public void testKeplerRangeWithOnBoardAntennaOffset() 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, 1.0);
    propagatorBuilder.setAttitudeProvider(new LofOffset(propagatorBuilder.getFrame(), LOFType.LVLH));
    final Vector3D antennaPhaseCenter = new Vector3D(-1.2, 2.3, -0.7);
    // create perfect range measurements with antenna offset
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new RangeMeasurementCreator(context, antennaPhaseCenter), 1.0, 3.0, 300.0);
    // create orbit estimator
    final BatchLSEstimator estimator = new BatchLSEstimator(new LevenbergMarquardtOptimizer(), propagatorBuilder);
    final OnBoardAntennaRangeModifier obaModifier = new OnBoardAntennaRangeModifier(antennaPhaseCenter);
    for (final ObservedMeasurement<?> range : measurements) {
        ((Range) range).addModifier(obaModifier);
        estimator.addMeasurement(range);
    }
    estimator.setParametersConvergenceThreshold(1.0e-2);
    estimator.setMaxIterations(10);
    estimator.setMaxEvaluations(20);
    estimator.setObserver(new BatchLSObserver() {

        int lastIter = 0;

        int lastEval = 0;

        /**
         * {@inheritDoc}
         */
        @Override
        public void evaluationPerformed(int iterationsCount, int evaluationscount, Orbit[] orbits, ParameterDriversList estimatedOrbitalParameters, ParameterDriversList estimatedPropagatorParameters, ParameterDriversList estimatedMeasurementsParameters, EstimationsProvider evaluationsProvider, Evaluation lspEvaluation) throws OrekitException {
            if (iterationsCount == lastIter) {
                Assert.assertEquals(lastEval + 1, evaluationscount);
            } else {
                Assert.assertEquals(lastIter + 1, iterationsCount);
            }
            lastIter = iterationsCount;
            lastEval = evaluationscount;
            Assert.assertEquals(measurements.size(), evaluationsProvider.getNumber());
            try {
                evaluationsProvider.getEstimatedMeasurement(-1);
                Assert.fail("an exception should have been thrown");
            } catch (OrekitException oe) {
                Assert.assertEquals(LocalizedCoreFormats.OUT_OF_RANGE_SIMPLE, oe.getSpecifier());
            }
            try {
                evaluationsProvider.getEstimatedMeasurement(measurements.size());
                Assert.fail("an exception should have been thrown");
            } catch (OrekitException oe) {
                Assert.assertEquals(LocalizedCoreFormats.OUT_OF_RANGE_SIMPLE, oe.getSpecifier());
            }
            AbsoluteDate previous = AbsoluteDate.PAST_INFINITY;
            for (int i = 0; i < evaluationsProvider.getNumber(); ++i) {
                AbsoluteDate current = evaluationsProvider.getEstimatedMeasurement(i).getDate();
                Assert.assertTrue(current.compareTo(previous) >= 0);
                previous = current;
            }
        }
    });
    ParameterDriver aDriver = estimator.getOrbitalParametersDrivers(true).getDrivers().get(0);
    Assert.assertEquals("a", aDriver.getName());
    aDriver.setValue(aDriver.getValue() + 1.2);
    aDriver.setReferenceDate(AbsoluteDate.GALILEO_EPOCH);
    EstimationTestUtils.checkFit(context, estimator, 2, 3, 0.0, 2.0e-5, 0.0, 5.2e-5, 0.0, 2.7e-5, 0.0, 1.1e-8);
    // got a default one
    for (final ParameterDriver driver : estimator.getOrbitalParametersDrivers(true).getDrivers()) {
        if ("a".equals(driver.getName())) {
            // user-specified reference date
            Assert.assertEquals(0, driver.getReferenceDate().durationFrom(AbsoluteDate.GALILEO_EPOCH), 1.0e-15);
        } else {
            // default reference date
            Assert.assertEquals(0, driver.getReferenceDate().durationFrom(propagatorBuilder.getInitialOrbitDate()), 1.0e-15);
        }
    }
}
Also used : Context(org.orekit.estimation.Context) Evaluation(org.hipparchus.optim.nonlinear.vector.leastsquares.LeastSquaresProblem.Evaluation) Orbit(org.orekit.orbits.Orbit) CartesianOrbit(org.orekit.orbits.CartesianOrbit) KeplerianOrbit(org.orekit.orbits.KeplerianOrbit) Range(org.orekit.estimation.measurements.Range) ParameterDriver(org.orekit.utils.ParameterDriver) AbsoluteDate(org.orekit.time.AbsoluteDate) LevenbergMarquardtOptimizer(org.hipparchus.optim.nonlinear.vector.leastsquares.LevenbergMarquardtOptimizer) OnBoardAntennaRangeModifier(org.orekit.estimation.measurements.modifiers.OnBoardAntennaRangeModifier) Vector3D(org.hipparchus.geometry.euclidean.threed.Vector3D) ParameterDriversList(org.orekit.utils.ParameterDriversList) NumericalPropagatorBuilder(org.orekit.propagation.conversion.NumericalPropagatorBuilder) BoundedPropagator(org.orekit.propagation.BoundedPropagator) Propagator(org.orekit.propagation.Propagator) OrekitException(org.orekit.errors.OrekitException) RangeMeasurementCreator(org.orekit.estimation.measurements.RangeMeasurementCreator) InterSatellitesRangeMeasurementCreator(org.orekit.estimation.measurements.InterSatellitesRangeMeasurementCreator) LofOffset(org.orekit.attitudes.LofOffset) ObservedMeasurement(org.orekit.estimation.measurements.ObservedMeasurement) EstimationsProvider(org.orekit.estimation.measurements.EstimationsProvider) 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