Examples with NormalizedSphericalHarmonicsProvider org.orekit.forces.gravity.potential.NormalizedSphericalHarmonicsProvider used on opensource projects

Example 11 with NormalizedSphericalHarmonicsProvider

use of org.orekit.forces.gravity.potential.NormalizedSphericalHarmonicsProvider in project Orekit by CS-SI.

the class SolidTidesTest method testStateJacobianVs80ImplementationNoPoleTide.

@Test
public void testStateJacobianVs80ImplementationNoPoleTide() throws OrekitException {
    Frame eme2000 = FramesFactory.getEME2000();
    TimeScale utc = TimeScalesFactory.getUTC();
    AbsoluteDate date = new AbsoluteDate(2964, 8, 12, 11, 30, 00.000, utc);
    Orbit orbit = new KeplerianOrbit(7201009.7124401, 1e-3, FastMath.toRadians(98.7), FastMath.toRadians(93.0), FastMath.toRadians(15.0 * 22.5), 0, PositionAngle.MEAN, eme2000, date, Constants.EIGEN5C_EARTH_MU);
    Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    UT1Scale ut1 = TimeScalesFactory.getUT1(IERSConventions.IERS_2010, true);
    NormalizedSphericalHarmonicsProvider gravityField = GravityFieldFactory.getConstantNormalizedProvider(5, 5);
    ForceModel forceModel = new SolidTides(itrf, gravityField.getAe(), gravityField.getMu(), gravityField.getTideSystem(), false, SolidTides.DEFAULT_STEP, SolidTides.DEFAULT_POINTS, IERSConventions.IERS_2010, ut1, CelestialBodyFactory.getSun(), CelestialBodyFactory.getMoon());
    Assert.assertTrue(forceModel.dependsOnPositionOnly());
    checkStateJacobianVs80Implementation(new SpacecraftState(orbit), forceModel, new LofOffset(orbit.getFrame(), LOFType.VVLH), 2.0e-15, false);
}

Example 12 with NormalizedSphericalHarmonicsProvider

use of org.orekit.forces.gravity.potential.NormalizedSphericalHarmonicsProvider in project Orekit by CS-SI.

the class SolidTidesTest method testStateJacobianVsFiniteDifferencesNoPoleTide.

@Test
public void testStateJacobianVsFiniteDifferencesNoPoleTide() throws OrekitException {
    Frame eme2000 = FramesFactory.getEME2000();
    TimeScale utc = TimeScalesFactory.getUTC();
    AbsoluteDate date = new AbsoluteDate(2964, 8, 12, 11, 30, 00.000, utc);
    Orbit orbit = new KeplerianOrbit(7201009.7124401, 1e-3, FastMath.toRadians(98.7), FastMath.toRadians(93.0), FastMath.toRadians(15.0 * 22.5), 0, PositionAngle.MEAN, eme2000, date, Constants.EIGEN5C_EARTH_MU);
    Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    UT1Scale ut1 = TimeScalesFactory.getUT1(IERSConventions.IERS_2010, true);
    NormalizedSphericalHarmonicsProvider gravityField = GravityFieldFactory.getConstantNormalizedProvider(5, 5);
    ForceModel forceModel = new SolidTides(itrf, gravityField.getAe(), gravityField.getMu(), gravityField.getTideSystem(), false, SolidTides.DEFAULT_STEP, SolidTides.DEFAULT_POINTS, IERSConventions.IERS_2010, ut1, CelestialBodyFactory.getSun(), CelestialBodyFactory.getMoon());
    checkStateJacobianVsFiniteDifferences(new SpacecraftState(orbit), forceModel, Propagator.DEFAULT_LAW, 10.0, 2.0e-10, false);
}

Example 13 with NormalizedSphericalHarmonicsProvider

use of org.orekit.forces.gravity.potential.NormalizedSphericalHarmonicsProvider in project SpriteOrbits by ProjectPersephone.

the class SpriteProp method createPropagator.

/**
 * Create a numerical propagator for a state.
 * @param state state to propagate
 * @param attitudeProvider provider for the attitude
 * @param crossSection cross section of the object
 * @param dragCoeff drag coefficient
 */
private Propagator createPropagator(final SpacecraftState state, final AttitudeProvider attitudeProvider, final double crossSection, final double dragCoeff) throws OrekitException {
    // see https://www.orekit.org/static/architecture/propagation.html
    // steps limits
    final double minStep = 0.001;
    final double maxStep = 1000;
    final double initStep = 60;
    // error control parameters (absolute and relative)
    final double positionError = 10.0;
    // we will propagate in Cartesian coordinates
    final OrbitType orbitType = OrbitType.CARTESIAN;
    final double[][] tolerances = NumericalPropagator.tolerances(positionError, state.getOrbit(), orbitType);
    // set up mathematical integrator
    AdaptiveStepsizeIntegrator integrator = new DormandPrince853Integrator(minStep, maxStep, tolerances[0], tolerances[1]);
    integrator.setInitialStepSize(initStep);
    // set up space dynamics propagator
    NumericalPropagator propagator = new NumericalPropagator(integrator);
    propagator.setOrbitType(orbitType);
    // add gravity field force model
    final NormalizedSphericalHarmonicsProvider gravityProvider = GravityFieldFactory.getNormalizedProvider(8, 8);
    propagator.addForceModel(new HolmesFeatherstoneAttractionModel(earth.getBodyFrame(), gravityProvider));
    // add atmospheric drag force model
    propagator.addForceModel(new DragForce(new HarrisPriester(sun, earth), new SphericalSpacecraft(crossSection, dragCoeff, 0.0, 0.0)));
    // set attitude mode
    propagator.setAttitudeProvider(attitudeProvider);
    propagator.setInitialState(state);
    return propagator;
}

Example 14 with NormalizedSphericalHarmonicsProvider

use of org.orekit.forces.gravity.potential.NormalizedSphericalHarmonicsProvider in project Orekit by CS-SI.

the class KalmanOrbitDeterminationTest method runReference.

/**
 * Use the physical models in the input file
 * Incorporate the initial reference values
 * And run the propagation until the last measurement to get the reference orbit at the same date
 * as the Kalman filter
 * @param input Input configuration file
 * @param orbitType Orbit type to use (calculation and display)
 * @param refPosition Initial reference position
 * @param refVelocity Initial reference velocity
 * @param refPropagationParameters Reference propagation parameters
 * @param kalmanFinalDate The final date of the Kalman filter
 * @return The reference orbit at the same date as the Kalman filter
 * @throws IOException Input file cannot be opened
 * @throws IllegalArgumentException Issue in key/value reading of input file
 * @throws OrekitException An Orekit exception... should be explicit
 * @throws ParseException Parsing of the input file or measurement file failed
 */
private Orbit runReference(final File input, final OrbitType orbitType, final Vector3D refPosition, final Vector3D refVelocity, final ParameterDriversList refPropagationParameters, final AbsoluteDate kalmanFinalDate) throws IOException, IllegalArgumentException, OrekitException, ParseException {
    // Read input parameters
    KeyValueFileParser<ParameterKey> parser = new KeyValueFileParser<ParameterKey>(ParameterKey.class);
    parser.parseInput(input.getAbsolutePath(), new FileInputStream(input));
    // Gravity field
    GravityFieldFactory.addPotentialCoefficientsReader(new ICGEMFormatReader("eigen-5c.gfc", true));
    final NormalizedSphericalHarmonicsProvider gravityField = createGravityField(parser);
    // Orbit initial guess
    Orbit initialRefOrbit = new CartesianOrbit(new PVCoordinates(refPosition, refVelocity), parser.getInertialFrame(ParameterKey.INERTIAL_FRAME), parser.getDate(ParameterKey.ORBIT_DATE, TimeScalesFactory.getUTC()), gravityField.getMu());
    // Convert to desired orbit type
    initialRefOrbit = orbitType.convertType(initialRefOrbit);
    // IERS conventions
    final IERSConventions conventions;
    if (!parser.containsKey(ParameterKey.IERS_CONVENTIONS)) {
        conventions = IERSConventions.IERS_2010;
    } else {
        conventions = IERSConventions.valueOf("IERS_" + parser.getInt(ParameterKey.IERS_CONVENTIONS));
    }
    // Central body
    final OneAxisEllipsoid body = createBody(parser);
    // Propagator builder
    final NumericalPropagatorBuilder propagatorBuilder = createPropagatorBuilder(parser, conventions, gravityField, body, initialRefOrbit);
    // Force the selected propagation parameters to their reference values
    if (refPropagationParameters != null) {
        for (DelegatingDriver refDriver : refPropagationParameters.getDrivers()) {
            for (DelegatingDriver driver : propagatorBuilder.getPropagationParametersDrivers().getDrivers()) {
                if (driver.getName().equals(refDriver.getName())) {
                    driver.setValue(refDriver.getValue());
                }
            }
        }
    }
    // Build the reference propagator
    final NumericalPropagator propagator = propagatorBuilder.buildPropagator(propagatorBuilder.getSelectedNormalizedParameters());
    // Propagate until last date and return the orbit
    return propagator.propagate(kalmanFinalDate).getOrbit();
}

Example 15 with NormalizedSphericalHarmonicsProvider

use of org.orekit.forces.gravity.potential.NormalizedSphericalHarmonicsProvider in project Orekit by CS-SI.

the class KalmanOrbitDeterminationTest method run.

/**
 * Function running the Kalman filter estimation.
 * @param input Input configuration file
 * @param orbitType Orbit type to use (calculation and display)
 * @param print Choose whether the results are printed on console or not
 * @param cartesianOrbitalP Orbital part of the initial covariance matrix in Cartesian formalism
 * @param cartesianOrbitalQ Orbital part of the process noise matrix in Cartesian formalism
 * @param propagationP Propagation part of the initial covariance matrix
 * @param propagationQ Propagation part of the process noise matrix
 * @param measurementP Measurement part of the initial covariance matrix
 * @param measurementQ Measurement part of the process noise matrix
 */
private ResultKalman run(final File input, final OrbitType orbitType, final boolean print, final RealMatrix cartesianOrbitalP, final RealMatrix cartesianOrbitalQ, final RealMatrix propagationP, final RealMatrix propagationQ, final RealMatrix measurementP, final RealMatrix measurementQ) throws IOException, IllegalArgumentException, OrekitException, ParseException {
    // Read input parameters
    KeyValueFileParser<ParameterKey> parser = new KeyValueFileParser<ParameterKey>(ParameterKey.class);
    parser.parseInput(input.getAbsolutePath(), new FileInputStream(input));
    // Log files
    final RangeLog rangeLog = new RangeLog();
    final RangeRateLog rangeRateLog = new RangeRateLog();
    final AzimuthLog azimuthLog = new AzimuthLog();
    final ElevationLog elevationLog = new ElevationLog();
    final PositionLog positionLog = new PositionLog();
    final VelocityLog velocityLog = new VelocityLog();
    // Gravity field
    GravityFieldFactory.addPotentialCoefficientsReader(new ICGEMFormatReader("eigen-5c.gfc", true));
    final NormalizedSphericalHarmonicsProvider gravityField = createGravityField(parser);
    // Orbit initial guess
    Orbit initialGuess = createOrbit(parser, gravityField.getMu());
    // Convert to desired orbit type
    initialGuess = orbitType.convertType(initialGuess);
    // IERS conventions
    final IERSConventions conventions;
    if (!parser.containsKey(ParameterKey.IERS_CONVENTIONS)) {
        conventions = IERSConventions.IERS_2010;
    } else {
        conventions = IERSConventions.valueOf("IERS_" + parser.getInt(ParameterKey.IERS_CONVENTIONS));
    }
    // Central body
    final OneAxisEllipsoid body = createBody(parser);
    // Propagator builder
    final NumericalPropagatorBuilder propagatorBuilder = createPropagatorBuilder(parser, conventions, gravityField, body, initialGuess);
    // Measurements
    final List<ObservedMeasurement<?>> measurements = new ArrayList<ObservedMeasurement<?>>();
    for (final String fileName : parser.getStringsList(ParameterKey.MEASUREMENTS_FILES, ',')) {
        measurements.addAll(readMeasurements(new File(input.getParentFile(), fileName), createStationsData(parser, body), createPVData(parser), createSatRangeBias(parser), createWeights(parser), createRangeOutliersManager(parser), createRangeRateOutliersManager(parser), createAzElOutliersManager(parser), createPVOutliersManager(parser)));
    }
    // Building the Kalman filter:
    // - Gather the estimated measurement parameters in a list
    // - Prepare the initial covariance matrix and the process noise matrix
    // - Build the Kalman filter
    // --------------------------------------------------------------------
    // Build the list of estimated measurements
    final ParameterDriversList estimatedMeasurementsParameters = new ParameterDriversList();
    for (ObservedMeasurement<?> measurement : measurements) {
        final List<ParameterDriver> drivers = measurement.getParametersDrivers();
        for (ParameterDriver driver : drivers) {
            if (driver.isSelected()) {
                // Add the driver
                estimatedMeasurementsParameters.add(driver);
            }
        }
    }
    // Sort the list lexicographically
    estimatedMeasurementsParameters.sort();
    // Orbital covariance matrix initialization
    // Jacobian of the orbital parameters w/r to Cartesian
    final double[][] dYdC = new double[6][6];
    initialGuess.getJacobianWrtCartesian(propagatorBuilder.getPositionAngle(), dYdC);
    final RealMatrix Jac = MatrixUtils.createRealMatrix(dYdC);
    RealMatrix orbitalP = Jac.multiply(cartesianOrbitalP.multiply(Jac.transpose()));
    // Orbital process noise matrix
    RealMatrix orbitalQ = Jac.multiply(cartesianOrbitalQ.multiply(Jac.transpose()));
    // Build the full covariance matrix and process noise matrix
    final int nbPropag = (propagationP != null) ? propagationP.getRowDimension() : 0;
    final int nbMeas = (measurementP != null) ? measurementP.getRowDimension() : 0;
    final RealMatrix initialP = MatrixUtils.createRealMatrix(6 + nbPropag + nbMeas, 6 + nbPropag + nbMeas);
    final RealMatrix Q = MatrixUtils.createRealMatrix(6 + nbPropag + nbMeas, 6 + nbPropag + nbMeas);
    // Orbital part
    initialP.setSubMatrix(orbitalP.getData(), 0, 0);
    Q.setSubMatrix(orbitalQ.getData(), 0, 0);
    // Propagation part
    if (propagationP != null) {
        initialP.setSubMatrix(propagationP.getData(), 6, 6);
        Q.setSubMatrix(propagationQ.getData(), 6, 6);
    }
    // Measurement part
    if (measurementP != null) {
        initialP.setSubMatrix(measurementP.getData(), 6 + nbPropag, 6 + nbPropag);
        Q.setSubMatrix(measurementQ.getData(), 6 + nbPropag, 6 + nbPropag);
    }
    // Build the Kalman
    KalmanEstimatorBuilder kalmanBuilder = new KalmanEstimatorBuilder();
    kalmanBuilder.builder(propagatorBuilder);
    kalmanBuilder.estimatedMeasurementsParameters(estimatedMeasurementsParameters);
    kalmanBuilder.initialCovarianceMatrix(initialP);
    kalmanBuilder.processNoiseMatrixProvider(new ConstantProcessNoise(Q));
    final KalmanEstimator kalman = kalmanBuilder.build();
    // Add an observer
    kalman.setObserver(new KalmanObserver() {

        /**
         * Date of the first measurement.
         */
        private AbsoluteDate t0;

        /**
         * {@inheritDoc}
         * @throws OrekitException
         */
        @Override
        @SuppressWarnings("unchecked")
        public void evaluationPerformed(final KalmanEstimation estimation) throws OrekitException {
            // Current measurement number, date and status
            final EstimatedMeasurement<?> estimatedMeasurement = estimation.getCorrectedMeasurement();
            final int currentNumber = estimation.getCurrentMeasurementNumber();
            final AbsoluteDate currentDate = estimatedMeasurement.getDate();
            final EstimatedMeasurement.Status currentStatus = estimatedMeasurement.getStatus();
            // Current estimated measurement
            final ObservedMeasurement<?> observedMeasurement = estimatedMeasurement.getObservedMeasurement();
            // Measurement type & Station name
            String measType = "";
            String stationName = "";
            // Register the measurement in the proper measurement logger
            if (observedMeasurement instanceof Range) {
                // Add the tuple (estimation, prediction) to the log
                rangeLog.add(currentNumber, (EstimatedMeasurement<Range>) estimatedMeasurement);
                // Measurement type & Station name
                measType = "RANGE";
                stationName = ((EstimatedMeasurement<Range>) estimatedMeasurement).getObservedMeasurement().getStation().getBaseFrame().getName();
            } else if (observedMeasurement instanceof RangeRate) {
                rangeRateLog.add(currentNumber, (EstimatedMeasurement<RangeRate>) estimatedMeasurement);
                measType = "RANGE_RATE";
                stationName = ((EstimatedMeasurement<RangeRate>) estimatedMeasurement).getObservedMeasurement().getStation().getBaseFrame().getName();
            } else if (observedMeasurement instanceof AngularAzEl) {
                azimuthLog.add(currentNumber, (EstimatedMeasurement<AngularAzEl>) estimatedMeasurement);
                elevationLog.add(currentNumber, (EstimatedMeasurement<AngularAzEl>) estimatedMeasurement);
                measType = "AZ_EL";
                stationName = ((EstimatedMeasurement<AngularAzEl>) estimatedMeasurement).getObservedMeasurement().getStation().getBaseFrame().getName();
            } else if (observedMeasurement instanceof PV) {
                positionLog.add(currentNumber, (EstimatedMeasurement<PV>) estimatedMeasurement);
                velocityLog.add(currentNumber, (EstimatedMeasurement<PV>) estimatedMeasurement);
                measType = "PV";
            }
            // Header
            if (print) {
                if (currentNumber == 1) {
                    // Set t0 to first measurement date
                    t0 = currentDate;
                    // Print header
                    final String formatHeader = "%-4s\t%-25s\t%15s\t%-10s\t%-10s\t%-20s\t%20s\t%20s";
                    String header = String.format(Locale.US, formatHeader, "Nb", "Epoch", "Dt[s]", "Status", "Type", "Station", "DP Corr", "DV Corr");
                    // Orbital drivers
                    for (DelegatingDriver driver : estimation.getEstimatedOrbitalParameters().getDrivers()) {
                        header += String.format(Locale.US, "\t%20s", driver.getName());
                        header += String.format(Locale.US, "\t%20s", "D" + driver.getName());
                    }
                    // Propagation drivers
                    for (DelegatingDriver driver : estimation.getEstimatedPropagationParameters().getDrivers()) {
                        header += String.format(Locale.US, "\t%20s", driver.getName());
                        header += String.format(Locale.US, "\t%20s", "D" + driver.getName());
                    }
                    // Measurements drivers
                    for (DelegatingDriver driver : estimation.getEstimatedMeasurementsParameters().getDrivers()) {
                        header += String.format(Locale.US, "\t%20s", driver.getName());
                        header += String.format(Locale.US, "\t%20s", "D" + driver.getName());
                    }
                    // Print header
                    System.out.println(header);
                }
                // Print current measurement info in terminal
                String line = "";
                // Line format
                final String lineFormat = "%4d\t%-25s\t%15.3f\t%-10s\t%-10s\t%-20s\t%20.9e\t%20.9e";
                // Orbital correction = DP & DV between predicted orbit and estimated orbit
                final Vector3D predictedP = estimation.getPredictedSpacecraftStates()[0].getPVCoordinates().getPosition();
                final Vector3D predictedV = estimation.getPredictedSpacecraftStates()[0].getPVCoordinates().getVelocity();
                final Vector3D estimatedP = estimation.getCorrectedSpacecraftStates()[0].getPVCoordinates().getPosition();
                final Vector3D estimatedV = estimation.getCorrectedSpacecraftStates()[0].getPVCoordinates().getVelocity();
                final double DPcorr = Vector3D.distance(predictedP, estimatedP);
                final double DVcorr = Vector3D.distance(predictedV, estimatedV);
                line = String.format(Locale.US, lineFormat, currentNumber, currentDate.toString(), currentDate.durationFrom(t0), currentStatus.toString(), measType, stationName, DPcorr, DVcorr);
                // Handle parameters printing (value and error)
                int jPar = 0;
                final RealMatrix Pest = estimation.getPhysicalEstimatedCovarianceMatrix();
                // Orbital drivers
                for (DelegatingDriver driver : estimation.getEstimatedOrbitalParameters().getDrivers()) {
                    line += String.format(Locale.US, "\t%20.9f", driver.getValue());
                    line += String.format(Locale.US, "\t%20.9e", FastMath.sqrt(Pest.getEntry(jPar, jPar)));
                    jPar++;
                }
                // Propagation drivers
                for (DelegatingDriver driver : estimation.getEstimatedPropagationParameters().getDrivers()) {
                    line += String.format(Locale.US, "\t%20.9f", driver.getValue());
                    line += String.format(Locale.US, "\t%20.9e", FastMath.sqrt(Pest.getEntry(jPar, jPar)));
                    jPar++;
                }
                // Measurements drivers
                for (DelegatingDriver driver : estimatedMeasurementsParameters.getDrivers()) {
                    line += String.format(Locale.US, "\t%20.9f", driver.getValue());
                    line += String.format(Locale.US, "\t%20.9e", FastMath.sqrt(Pest.getEntry(jPar, jPar)));
                    jPar++;
                }
                // Print the line
                System.out.println(line);
            }
        }
    });
    // Process the list measurements
    final Orbit estimated = kalman.processMeasurements(measurements).getInitialState().getOrbit();
    // Get the last estimated physical covariances
    final RealMatrix covarianceMatrix = kalman.getPhysicalEstimatedCovarianceMatrix();
    // Parameters and measurements.
    final ParameterDriversList propagationParameters = kalman.getPropagationParametersDrivers(true);
    final ParameterDriversList measurementsParameters = kalman.getEstimatedMeasurementsParameters();
    // Eventually, print parameter changes, statistics and covariances
    if (print) {
        // Display parameter change for non orbital drivers
        int length = 0;
        for (final ParameterDriver parameterDriver : propagationParameters.getDrivers()) {
            length = FastMath.max(length, parameterDriver.getName().length());
        }
        for (final ParameterDriver parameterDriver : measurementsParameters.getDrivers()) {
            length = FastMath.max(length, parameterDriver.getName().length());
        }
        if (propagationParameters.getNbParams() > 0) {
            displayParametersChanges(System.out, "Estimated propagator parameters changes: ", true, length, propagationParameters);
        }
        if (measurementsParameters.getNbParams() > 0) {
            displayParametersChanges(System.out, "Estimated measurements parameters changes: ", true, length, measurementsParameters);
        }
        // Measurements statistics summary
        System.out.println("");
        rangeLog.displaySummary(System.out);
        rangeRateLog.displaySummary(System.out);
        azimuthLog.displaySummary(System.out);
        elevationLog.displaySummary(System.out);
        positionLog.displaySummary(System.out);
        velocityLog.displaySummary(System.out);
        // Covariances and sigmas
        displayFinalCovariances(System.out, kalman);
    }
    // Instantiation of the results
    return new ResultKalman(propagationParameters, measurementsParameters, kalman.getCurrentMeasurementNumber(), estimated.getPVCoordinates(), rangeLog.createStatisticsSummary(), rangeRateLog.createStatisticsSummary(), azimuthLog.createStatisticsSummary(), elevationLog.createStatisticsSummary(), positionLog.createStatisticsSummary(), velocityLog.createStatisticsSummary(), covarianceMatrix);
}