use of org.orekit.propagation.conversion.NumericalPropagatorBuilder in project Orekit by CS-SI.
the class RangeTest method genericTestStateDerivatives.
void genericTestStateDerivatives(final boolean isModifier, final boolean printResults, final double refErrorsPMedian, final double refErrorsPMean, final double refErrorsPMax, final double refErrorsVMedian, final double refErrorsVMean, final double refErrorsVMax) 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
final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new RangeMeasurementCreator(context), 1.0, 3.0, 300.0);
// Lists for results' storage - Used only for derivatives with respect to state
// "final" value to be seen by "handleStep" function of the propagator
final List<Double> errorsP = new ArrayList<Double>();
final List<Double> errorsV = new ArrayList<Double>();
// Set master mode
// Use a lambda function to implement "handleStep" function
propagator.setMasterMode((OrekitStepInterpolator interpolator, boolean isLast) -> {
for (final ObservedMeasurement<?> measurement : measurements) {
// Play test if the measurement date is between interpolator previous and current date
if ((measurement.getDate().durationFrom(interpolator.getPreviousState().getDate()) > 0.) && (measurement.getDate().durationFrom(interpolator.getCurrentState().getDate()) <= 0.)) {
// Add modifiers if test implies it
final RangeTroposphericDelayModifier modifier = new RangeTroposphericDelayModifier(SaastamoinenModel.getStandardModel());
if (isModifier) {
((Range) measurement).addModifier(modifier);
}
// We intentionally propagate to a date which is close to the
// real spacecraft state but is *not* the accurate date, by
// compensating only part of the downlink delay. This is done
// in order to validate the partial derivatives with respect
// to velocity. If we had chosen the proper state date, the
// range would have depended only on the current position but
// not on the current velocity.
final double meanDelay = measurement.getObservedValue()[0] / Constants.SPEED_OF_LIGHT;
final AbsoluteDate date = measurement.getDate().shiftedBy(-0.75 * meanDelay);
final SpacecraftState state = interpolator.getInterpolatedState(date);
final double[][] jacobian = measurement.estimate(0, 0, new SpacecraftState[] { state }).getStateDerivatives(0);
// Jacobian reference value
final double[][] jacobianRef;
// Compute a reference value using finite differences
jacobianRef = Differentiation.differentiate(new StateFunction() {
public double[] value(final SpacecraftState state) throws OrekitException {
return measurement.estimate(0, 0, new SpacecraftState[] { state }).getEstimatedValue();
}
}, measurement.getDimension(), propagator.getAttitudeProvider(), OrbitType.CARTESIAN, PositionAngle.TRUE, 2.0, 3).value(state);
Assert.assertEquals(jacobianRef.length, jacobian.length);
Assert.assertEquals(jacobianRef[0].length, jacobian[0].length);
// Errors & relative errors on the Jacobian
double[][] dJacobian = new double[jacobian.length][jacobian[0].length];
double[][] dJacobianRelative = new double[jacobian.length][jacobian[0].length];
for (int i = 0; i < jacobian.length; ++i) {
for (int j = 0; j < jacobian[i].length; ++j) {
dJacobian[i][j] = jacobian[i][j] - jacobianRef[i][j];
dJacobianRelative[i][j] = FastMath.abs(dJacobian[i][j] / jacobianRef[i][j]);
if (j < 3) {
errorsP.add(dJacobianRelative[i][j]);
} else {
errorsV.add(dJacobianRelative[i][j]);
}
}
}
// Print values in console ?
if (printResults) {
String stationName = ((Range) measurement).getStation().getBaseFrame().getName();
System.out.format(Locale.US, "%-15s %-23s %-23s " + "%10.3e %10.3e %10.3e " + "%10.3e %10.3e %10.3e " + "%10.3e %10.3e %10.3e " + "%10.3e %10.3e %10.3e%n", stationName, measurement.getDate(), date, dJacobian[0][0], dJacobian[0][1], dJacobian[0][2], dJacobian[0][3], dJacobian[0][4], dJacobian[0][5], dJacobianRelative[0][0], dJacobianRelative[0][1], dJacobianRelative[0][2], dJacobianRelative[0][3], dJacobianRelative[0][4], dJacobianRelative[0][5]);
}
}
// End if measurement date between previous and current interpolator step
}
// End for loop on the measurements
});
// Print results on console ?
if (printResults) {
System.out.format(Locale.US, "%-15s %-23s %-23s " + "%10s %10s %10s " + "%10s %10s %10s " + "%10s %10s %10s " + "%10s %10s %10s%n", "Station", "Measurement Date", "State Date", "ΔdPx", "ΔdPy", "ΔdPz", "ΔdVx", "ΔdVy", "ΔdVz", "rel ΔdPx", "rel ΔdPy", "rel ΔdPz", "rel ΔdVx", "rel ΔdVy", "rel ΔdVz");
}
// Rewind the propagator to initial date
propagator.propagate(context.initialOrbit.getDate());
// Sort measurements chronologically
measurements.sort(new ChronologicalComparator());
// Propagate to final measurement's date
propagator.propagate(measurements.get(measurements.size() - 1).getDate());
// Convert lists to double[] and evaluate some statistics
final double[] relErrorsP = errorsP.stream().mapToDouble(Double::doubleValue).toArray();
final double[] relErrorsV = errorsV.stream().mapToDouble(Double::doubleValue).toArray();
final double errorsPMedian = new Median().evaluate(relErrorsP);
final double errorsPMean = new Mean().evaluate(relErrorsP);
final double errorsPMax = new Max().evaluate(relErrorsP);
final double errorsVMedian = new Median().evaluate(relErrorsV);
final double errorsVMean = new Mean().evaluate(relErrorsV);
final double errorsVMax = new Max().evaluate(relErrorsV);
// Print the results on console ?
if (printResults) {
System.out.println();
System.out.format(Locale.US, "Relative errors dR/dP -> Median: %6.3e / Mean: %6.3e / Max: %6.3e%n", errorsPMedian, errorsPMean, errorsPMax);
System.out.format(Locale.US, "Relative errors dR/dV -> Median: %6.3e / Mean: %6.3e / Max: %6.3e%n", errorsVMedian, errorsVMean, errorsVMax);
}
Assert.assertEquals(0.0, errorsPMedian, refErrorsPMedian);
Assert.assertEquals(0.0, errorsPMean, refErrorsPMean);
Assert.assertEquals(0.0, errorsPMax, refErrorsPMax);
Assert.assertEquals(0.0, errorsVMedian, refErrorsVMedian);
Assert.assertEquals(0.0, errorsVMean, refErrorsVMean);
Assert.assertEquals(0.0, errorsVMax, refErrorsVMax);
}
use of org.orekit.propagation.conversion.NumericalPropagatorBuilder in project Orekit by CS-SI.
the class Context method createBuilder.
public NumericalPropagatorBuilder createBuilder(final OrbitType orbitType, final PositionAngle positionAngle, final boolean perfectStart, final double minStep, final double maxStep, final double dP, final Force... forces) throws OrekitException {
final Orbit startOrbit;
if (perfectStart) {
// orbit estimation will start from a perfect orbit
startOrbit = initialOrbit;
} else {
// orbit estimation will start from a wrong point
final Vector3D initialPosition = initialOrbit.getPVCoordinates().getPosition();
final Vector3D initialVelocity = initialOrbit.getPVCoordinates().getVelocity();
final Vector3D wrongPosition = initialPosition.add(new Vector3D(1000.0, 0, 0));
final Vector3D wrongVelocity = initialVelocity.add(new Vector3D(0, 0, 0.01));
startOrbit = new CartesianOrbit(new PVCoordinates(wrongPosition, wrongVelocity), initialOrbit.getFrame(), initialOrbit.getDate(), initialOrbit.getMu());
}
final NumericalPropagatorBuilder propagatorBuilder = new NumericalPropagatorBuilder(orbitType.convertType(startOrbit), new DormandPrince853IntegratorBuilder(minStep, maxStep, dP), positionAngle, dP);
for (Force force : forces) {
propagatorBuilder.addForceModel(force.getForceModel(this));
}
return propagatorBuilder;
}
use of org.orekit.propagation.conversion.NumericalPropagatorBuilder 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());
}
use of org.orekit.propagation.conversion.NumericalPropagatorBuilder 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);
}
}
}
use of org.orekit.propagation.conversion.NumericalPropagatorBuilder 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);
}
}
}
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