Examples with Orbit org.orekit.orbits.Orbit used on opensource projects

Example 21 with Orbit

use of org.orekit.orbits.Orbit in project Orekit by CS-SI.

the class BoxAndSolarArraySpacecraftTest method setUp.

@Before
public void setUp() {
    try {
        Utils.setDataRoot("regular-data");
        mu = 3.9860047e14;
        double ae = 6.378137e6;
        double c20 = -1.08263e-3;
        double c30 = 2.54e-6;
        double c40 = 1.62e-6;
        double c50 = 2.3e-7;
        double c60 = -5.5e-7;
        AbsoluteDate date = new AbsoluteDate(new DateComponents(1970, 7, 1), new TimeComponents(13, 59, 27.816), TimeScalesFactory.getUTC());
        // Satellite position as circular parameters, raan chosen to have sun elevation with
        // respect to orbit plane roughly evolving roughly from 15 to 15.2 degrees in the test range
        Orbit circ = new CircularOrbit(7178000.0, 0.5e-4, -0.5e-4, FastMath.toRadians(50.), FastMath.toRadians(280), FastMath.toRadians(10.0), PositionAngle.MEAN, FramesFactory.getEME2000(), date, mu);
        propagator = new EcksteinHechlerPropagator(circ, new LofOffset(circ.getFrame(), LOFType.VVLH), ae, mu, c20, c30, c40, c50, c60);
    } catch (OrekitException oe) {
        Assert.fail(oe.getLocalizedMessage());
    }
}

Example 22 with Orbit

use of org.orekit.orbits.Orbit in project Orekit by CS-SI.

the class EstimationTestUtils method checkKalmanFit.

/**
 * Checker for Kalman estimator validation
 * @param context context used for the test
 * @param kalman Kalman filter
 * @param measurements List of observed measurements to be processed by the Kalman
 * @param refOrbit Reference orbit at last measurement date
 * @param expectedDeltaPos Expected position difference between estimated orbit and reference orbit
 * @param posEps Tolerance on expected position difference
 * @param expectedDeltaVel Expected velocity difference between estimated orbit and reference orbit
 * @param velEps Tolerance on expected velocity difference
 * @param expectedSigmasPos Expected values for covariance matrix on position
 * @param sigmaPosEps Tolerance on expected covariance matrix on position
 * @param expectedSigmasVel Expected values for covariance matrix on velocity
 * @param sigmaVelEps Tolerance on expected covariance matrix on velocity
 * @throws OrekitException
 */
public static void checkKalmanFit(final Context context, final KalmanEstimator kalman, final List<ObservedMeasurement<?>> measurements, final Orbit refOrbit, final PositionAngle positionAngle, final double expectedDeltaPos, final double posEps, final double expectedDeltaVel, final double velEps, final double[] expectedSigmasPos, final double sigmaPosEps, final double[] expectedSigmasVel, final double sigmaVelEps) throws OrekitException {
    // Add the measurements to the Kalman filter
    NumericalPropagator estimated = kalman.processMeasurements(measurements);
    // Check the number of measurements processed by the filter
    Assert.assertEquals(measurements.size(), kalman.getCurrentMeasurementNumber());
    // Get the last estimation
    final Orbit estimatedOrbit = estimated.getInitialState().getOrbit();
    final Vector3D estimatedPosition = estimatedOrbit.getPVCoordinates().getPosition();
    final Vector3D estimatedVelocity = estimatedOrbit.getPVCoordinates().getVelocity();
    // Get the last covariance matrix estimation
    final RealMatrix estimatedP = kalman.getPhysicalEstimatedCovarianceMatrix();
    // Convert the orbital part to Cartesian formalism
    // Assuming all 6 orbital parameters are estimated by the filter
    final double[][] dCdY = new double[6][6];
    estimatedOrbit.getJacobianWrtParameters(positionAngle, dCdY);
    final RealMatrix Jacobian = MatrixUtils.createRealMatrix(dCdY);
    final RealMatrix estimatedCartesianP = Jacobian.multiply(estimatedP.getSubMatrix(0, 5, 0, 5)).multiply(Jacobian.transpose());
    // Get the final sigmas (ie.sqrt of the diagonal of the Cartesian orbital covariance matrix)
    final double[] sigmas = new double[6];
    for (int i = 0; i < 6; i++) {
        sigmas[i] = FastMath.sqrt(estimatedCartesianP.getEntry(i, i));
    }
    // // FIXME: debug
    // final double dPos = Vector3D.distance(refOrbit.getPVCoordinates().getPosition(), estimatedPosition);
    // final double dVel = Vector3D.distance(refOrbit.getPVCoordinates().getVelocity(), estimatedVelocity);
    // System.out.println("Nb Meas = " + kalman.getCurrentMeasurementNumber());
    // System.out.println("dPos    = " + dPos + " m");
    // System.out.println("dVel    = " + dVel + " m/s");
    // System.out.println("sigmas  = " + sigmas[0] + " "
    // + sigmas[1] + " "
    // + sigmas[2] + " "
    // + sigmas[3] + " "
    // + sigmas[4] + " "
    // + sigmas[5]);
    // //debug
    // Check the final orbit estimation & PV sigmas
    Assert.assertEquals(expectedDeltaPos, Vector3D.distance(refOrbit.getPVCoordinates().getPosition(), estimatedPosition), posEps);
    Assert.assertEquals(expectedDeltaVel, Vector3D.distance(refOrbit.getPVCoordinates().getVelocity(), estimatedVelocity), velEps);
    for (int i = 0; i < 3; i++) {
        Assert.assertEquals(expectedSigmasPos[i], sigmas[i], sigmaPosEps);
        Assert.assertEquals(expectedSigmasVel[i], sigmas[i + 3], sigmaVelEps);
    }
}

Example 23 with Orbit

use of org.orekit.orbits.Orbit in project Orekit by CS-SI.

the class EstimationTestUtils method checkFit.

/**
 * Checker for batch LS estimator validation
 * @param context Context used for the test
 * @param estimator Batch LS estimator
 * @param iterations Number of iterations expected
 * @param evaluations Number of evaluations expected
 * @param expectedRMS Expected RMS value
 * @param rmsEps Tolerance on expected RMS
 * @param expectedMax Expected weighted residual maximum
 * @param maxEps Tolerance on weighted residual maximum
 * @param expectedDeltaPos Expected position difference between estimated orbit and initial orbit
 * @param posEps Tolerance on expected position difference
 * @param expectedDeltaVel Expected velocity difference between estimated orbit and initial orbit
 * @param velEps Tolerance on expected velocity difference
 * @throws OrekitException
 */
public static void checkFit(final Context context, final BatchLSEstimator estimator, final int iterations, final int evaluations, final double expectedRMS, final double rmsEps, final double expectedMax, final double maxEps, final double expectedDeltaPos, final double posEps, final double expectedDeltaVel, final double velEps) throws OrekitException {
    final Orbit estimatedOrbit = estimator.estimate()[0].getInitialState().getOrbit();
    final Vector3D estimatedPosition = estimatedOrbit.getPVCoordinates().getPosition();
    final Vector3D estimatedVelocity = estimatedOrbit.getPVCoordinates().getVelocity();
    Assert.assertEquals(iterations, estimator.getIterationsCount());
    Assert.assertEquals(evaluations, estimator.getEvaluationsCount());
    Optimum optimum = estimator.getOptimum();
    Assert.assertEquals(iterations, optimum.getIterations());
    Assert.assertEquals(evaluations, optimum.getEvaluations());
    int k = 0;
    double sum = 0;
    double max = 0;
    for (final Map.Entry<ObservedMeasurement<?>, EstimatedMeasurement<?>> entry : estimator.getLastEstimations().entrySet()) {
        final ObservedMeasurement<?> m = entry.getKey();
        final EstimatedMeasurement<?> e = entry.getValue();
        final double[] weight = m.getBaseWeight();
        final double[] sigma = m.getTheoreticalStandardDeviation();
        final double[] observed = m.getObservedValue();
        final double[] theoretical = e.getEstimatedValue();
        for (int i = 0; i < m.getDimension(); ++i) {
            final double weightedResidual = weight[i] * (theoretical[i] - observed[i]) / sigma[i];
            ++k;
            sum += weightedResidual * weightedResidual;
            max = FastMath.max(max, FastMath.abs(weightedResidual));
        }
    }
    Assert.assertEquals(expectedRMS, FastMath.sqrt(sum / k), rmsEps);
    Assert.assertEquals(expectedMax, max, maxEps);
    Assert.assertEquals(expectedDeltaPos, Vector3D.distance(context.initialOrbit.getPVCoordinates().getPosition(), estimatedPosition), posEps);
    Assert.assertEquals(expectedDeltaVel, Vector3D.distance(context.initialOrbit.getPVCoordinates().getVelocity(), estimatedVelocity), velEps);
}

Example 24 with Orbit

use of org.orekit.orbits.Orbit in project Orekit by CS-SI.

the class BatchLSEstimatorTest method testMultiSatWithParameters.

/**
 * A modified version of the previous test with a selection of propagation drivers to estimate
 *  One common (µ)
 *  Some specifics for each satellite (Cr and Ca)
 *
 * @throws OrekitException
 */
@Test
public void testMultiSatWithParameters() throws OrekitException {
    // Test: Set the propagator drivers to estimate for each satellite
    final boolean muEstimated = true;
    final boolean crEstimated1 = true;
    final boolean caEstimated1 = true;
    final boolean crEstimated2 = true;
    final boolean caEstimated2 = false;
    // Builder sat 1
    final 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, Force.POTENTIAL, Force.SOLAR_RADIATION_PRESSURE);
    // Adding selection of parameters
    String satName = "sat 1";
    for (DelegatingDriver driver : propagatorBuilder1.getPropagationParametersDrivers().getDrivers()) {
        if (driver.getName().equals("central attraction coefficient")) {
            driver.setSelected(muEstimated);
        }
        if (driver.getName().equals(RadiationSensitive.REFLECTION_COEFFICIENT)) {
            driver.setName(driver.getName() + " " + satName);
            driver.setSelected(crEstimated1);
        }
        if (driver.getName().equals(RadiationSensitive.ABSORPTION_COEFFICIENT)) {
            driver.setName(driver.getName() + " " + satName);
            driver.setSelected(caEstimated1);
        }
    }
    // Builder for sat 2
    final Context context2 = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
    final NumericalPropagatorBuilder propagatorBuilder2 = context2.createBuilder(OrbitType.KEPLERIAN, PositionAngle.TRUE, true, 1.0e-6, 60.0, 1.0, Force.POTENTIAL, Force.SOLAR_RADIATION_PRESSURE);
    // Adding selection of parameters
    satName = "sat 2";
    for (ParameterDriver driver : propagatorBuilder2.getPropagationParametersDrivers().getDrivers()) {
        if (driver.getName().equals("central attraction coefficient")) {
            driver.setSelected(muEstimated);
        }
        if (driver.getName().equals(RadiationSensitive.REFLECTION_COEFFICIENT)) {
            driver.setName(driver.getName() + " " + satName);
            driver.setSelected(crEstimated2);
        }
        if (driver.getName().equals(RadiationSensitive.ABSORPTION_COEFFICIENT)) {
            driver.setName(driver.getName() + " " + satName);
            driver.setSelected(caEstimated2);
        }
    }
    // 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;
            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, 4, 5, 0.0, 6.0e-06, 0.0, 1.7e-05, 0.0, 4.4e-07, 0.0, 1.7e-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()), 5.8e-6);
    Assert.assertEquals(0.0, Vector3D.distance(closeOrbit.getPVCoordinates().getVelocity(), determined.getPVCoordinates().getVelocity()), 3.5e-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);
        }
    }
}

Example 25 with Orbit

use of org.orekit.orbits.Orbit in project Orekit by CS-SI.

the class BatchLSEstimatorTest method testWrappedException.

@Test
public void testWrappedException() 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);
    // 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);
    // create orbit estimator
    final BatchLSEstimator estimator = new BatchLSEstimator(new LevenbergMarquardtOptimizer(), propagatorBuilder);
    for (final ObservedMeasurement<?> range : measurements) {
        estimator.addMeasurement(range);
    }
    estimator.setParametersConvergenceThreshold(1.0e-2);
    estimator.setMaxIterations(10);
    estimator.setMaxEvaluations(20);
    estimator.setObserver(new BatchLSObserver() {

        /**
         * {@inheritDoc}
         */
        @Override
        public void evaluationPerformed(int iterationsCount, int evaluationscount, Orbit[] orbits, ParameterDriversList estimatedOrbitalParameters, ParameterDriversList estimatedPropagatorParameters, ParameterDriversList estimatedMeasurementsParameters, EstimationsProvider evaluationsProvider, Evaluation lspEvaluation) throws DummyException {
            throw new DummyException();
        }
    });
    try {
        EstimationTestUtils.checkFit(context, estimator, 3, 4, 0.0, 1.5e-6, 0.0, 3.2e-6, 0.0, 3.8e-7, 0.0, 1.5e-10);
        Assert.fail("an exception should have been thrown");
    } catch (DummyException de) {
    // expected
    }
}