Examples with ParameterDriver org.orekit.utils.ParameterDriver used on opensource projects

Example 31 with ParameterDriver

use of org.orekit.utils.ParameterDriver in project Orekit by CS-SI.

the class KalmanEstimatorTest method testKeplerianRange.

/**
 * Perfect range measurements with a biased start
 * Keplerian formalism
 * @throws OrekitException
 */
@Test
public void testKeplerianRange() throws OrekitException {
    // Create context
    Context context = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
    // Create initial orbit and propagator builder
    final OrbitType orbitType = OrbitType.KEPLERIAN;
    final PositionAngle positionAngle = PositionAngle.TRUE;
    final boolean perfectStart = true;
    final double minStep = 1.e-6;
    final double maxStep = 60.;
    final double dP = 1.;
    final NumericalPropagatorBuilder propagatorBuilder = context.createBuilder(orbitType, positionAngle, perfectStart, minStep, maxStep, dP);
    // Create perfect range measurements
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new RangeMeasurementCreator(context), 1.0, 4.0, 60.0);
    // Reference propagator for estimation performances
    final NumericalPropagator referencePropagator = propagatorBuilder.buildPropagator(propagatorBuilder.getSelectedNormalizedParameters());
    // Reference position/velocity at last measurement date
    final Orbit refOrbit = referencePropagator.propagate(measurements.get(measurements.size() - 1).getDate()).getOrbit();
    // Change semi-major axis of 1.2m as in the batch test
    ParameterDriver aDriver = propagatorBuilder.getOrbitalParametersDrivers().getDrivers().get(0);
    aDriver.setValue(aDriver.getValue() + 1.2);
    aDriver.setReferenceDate(AbsoluteDate.GALILEO_EPOCH);
    // Cartesian covariance matrix initialization
    // 100m on position / 1e-2m/s on velocity
    final RealMatrix cartesianP = MatrixUtils.createRealDiagonalMatrix(new double[] { 100., 100., 100., 1e-2, 1e-2, 1e-2 });
    // Jacobian of the orbital parameters w/r to Cartesian
    final Orbit initialOrbit = orbitType.convertType(context.initialOrbit);
    final double[][] dYdC = new double[6][6];
    initialOrbit.getJacobianWrtCartesian(PositionAngle.TRUE, dYdC);
    final RealMatrix Jac = MatrixUtils.createRealMatrix(dYdC);
    // Keplerian initial covariance matrix
    final RealMatrix initialP = Jac.multiply(cartesianP.multiply(Jac.transpose()));
    // Process noise matrix is set to 0 here
    RealMatrix Q = MatrixUtils.createRealMatrix(6, 6);
    // Build the Kalman filter
    final KalmanEstimatorBuilder kalmanBuilder = new KalmanEstimatorBuilder();
    kalmanBuilder.builder(propagatorBuilder);
    kalmanBuilder.estimatedMeasurementsParameters(new ParameterDriversList());
    kalmanBuilder.initialCovarianceMatrix(initialP);
    kalmanBuilder.processNoiseMatrixProvider(new ConstantProcessNoise(Q));
    final KalmanEstimator kalman = kalmanBuilder.build();
    // Filter the measurements and check the results
    final double expectedDeltaPos = 0.;
    final double posEps = 1.77e-4;
    final double expectedDeltaVel = 0.;
    final double velEps = 7.93e-8;
    final double[] expectedSigmasPos = { 0.742488, 0.281910, 0.563217 };
    final double sigmaPosEps = 1e-6;
    final double[] expectedSigmasVel = { 2.206622e-4, 1.306669e-4, 1.293996e-4 };
    final double sigmaVelEps = 1e-10;
    EstimationTestUtils.checkKalmanFit(context, kalman, measurements, refOrbit, positionAngle, expectedDeltaPos, posEps, expectedDeltaVel, velEps, expectedSigmasPos, sigmaPosEps, expectedSigmasVel, sigmaVelEps);
}

Example 32 with ParameterDriver

use of org.orekit.utils.ParameterDriver in project Orekit by CS-SI.

the class KalmanOrbitDeterminationTest method displayParametersChanges.

/**
 * Display parameters changes.
 * @param stream output stream
 * @param header header message
 * @param sort if true, parameters will be sorted lexicographically
 * @param parameters parameters list
 */
private void displayParametersChanges(final PrintStream out, final String header, final boolean sort, final int length, final ParameterDriversList parameters) {
    List<ParameterDriver> list = new ArrayList<ParameterDriver>(parameters.getDrivers());
    if (sort) {
        // sort the parameters lexicographically
        Collections.sort(list, new Comparator<ParameterDriver>() {

            /**
             * {@inheritDoc}
             */
            @Override
            public int compare(final ParameterDriver pd1, final ParameterDriver pd2) {
                return pd1.getName().compareTo(pd2.getName());
            }
        });
    }
    out.println(header);
    int index = 0;
    for (final ParameterDriver parameter : list) {
        if (parameter.isSelected()) {
            final double factor;
            if (parameter.getName().endsWith("/az bias") || parameter.getName().endsWith("/el bias")) {
                factor = FastMath.toDegrees(1.0);
            } else {
                factor = 1.0;
            }
            final double initial = parameter.getReferenceValue();
            final double value = parameter.getValue();
            out.format(Locale.US, "  %2d %s", ++index, parameter.getName());
            for (int i = parameter.getName().length(); i < length; ++i) {
                out.format(Locale.US, " ");
            }
            out.format(Locale.US, "  %+.12f  (final value:  % .12f)%n", factor * (value - initial), factor * value);
        }
    }
}

Example 33 with ParameterDriver

use of org.orekit.utils.ParameterDriver in project Orekit by CS-SI.

the class KalmanOrbitDeterminationTest method displayFinalCovariances.

/**
 * Display covariances and sigmas as predicted by a Kalman filter at date t.
 * @throws OrekitException
 */
private void displayFinalCovariances(final PrintStream logStream, final KalmanEstimator kalman) throws OrekitException {
    // // Get kalman estimated propagator
    // final NumericalPropagator kalmanProp = kalman.getProcessModel().getEstimatedPropagator();
    // 
    // // Link the partial derivatives to this propagator
    // final String equationName = "kalman-derivatives";
    // PartialDerivativesEquations kalmanDerivatives = new PartialDerivativesEquations(equationName, kalmanProp);
    // 
    // // Initialize the derivatives
    // final SpacecraftState rawState = kalmanProp.getInitialState();
    // final SpacecraftState stateWithDerivatives =
    // kalmanDerivatives.setInitialJacobians(rawState);
    // kalmanProp.resetInitialState(stateWithDerivatives);
    // 
    // // Propagate to target date
    // final SpacecraftState kalmanState = kalmanProp.propagate(targetDate);
    // 
    // // Compute STM
    // RealMatrix STM = kalman.getProcessModel().getErrorStateTransitionMatrix(kalmanState, kalmanDerivatives);
    // 
    // // Compute covariance matrix
    // RealMatrix P = kalman.getProcessModel().unNormalizeCovarianceMatrix(kalman.predictCovariance(STM,
    // kalman.getProcessModel().getProcessNoiseMatrix()));
    final RealMatrix P = kalman.getPhysicalEstimatedCovarianceMatrix();
    final String[] paramNames = new String[P.getRowDimension()];
    int index = 0;
    int paramSize = 0;
    for (final ParameterDriver driver : kalman.getOrbitalParametersDrivers(true).getDrivers()) {
        paramNames[index++] = driver.getName();
        paramSize = FastMath.max(paramSize, driver.getName().length());
    }
    for (final ParameterDriver driver : kalman.getPropagationParametersDrivers(true).getDrivers()) {
        paramNames[index++] = driver.getName();
        paramSize = FastMath.max(paramSize, driver.getName().length());
    }
    for (final ParameterDriver driver : kalman.getEstimatedMeasurementsParameters().getDrivers()) {
        paramNames[index++] = driver.getName();
        paramSize = FastMath.max(paramSize, driver.getName().length());
    }
    if (paramSize < 20) {
        paramSize = 20;
    }
    // Header
    logStream.format("\n%s\n", "Kalman Final Covariances:");
    // logStream.format(Locale.US, "\tDate: %-23s UTC\n",
    // targetDate.toString(TimeScalesFactory.getUTC()));
    logStream.format(Locale.US, "\tDate: %-23s UTC\n", kalman.getCurrentDate().toString(TimeScalesFactory.getUTC()));
    // Covariances
    String strFormat = String.format("%%%2ds  ", paramSize);
    logStream.format(strFormat, "Covariances:");
    for (int i = 0; i < P.getRowDimension(); i++) {
        logStream.format(Locale.US, strFormat, paramNames[i]);
    }
    logStream.println("");
    String numFormat = String.format("%%%2d.6f  ", paramSize);
    for (int i = 0; i < P.getRowDimension(); i++) {
        logStream.format(Locale.US, strFormat, paramNames[i]);
        for (int j = 0; j <= i; j++) {
            logStream.format(Locale.US, numFormat, P.getEntry(i, j));
        }
        logStream.println("");
    }
    // Correlation coeff
    final double[] sigmas = new double[P.getRowDimension()];
    for (int i = 0; i < P.getRowDimension(); i++) {
        sigmas[i] = FastMath.sqrt(P.getEntry(i, i));
    }
    logStream.format("\n" + strFormat, "Corr coef:");
    for (int i = 0; i < P.getRowDimension(); i++) {
        logStream.format(Locale.US, strFormat, paramNames[i]);
    }
    logStream.println("");
    for (int i = 0; i < P.getRowDimension(); i++) {
        logStream.format(Locale.US, strFormat, paramNames[i]);
        for (int j = 0; j <= i; j++) {
            logStream.format(Locale.US, numFormat, P.getEntry(i, j) / (sigmas[i] * sigmas[j]));
        }
        logStream.println("");
    }
    // Sigmas
    logStream.format("\n" + strFormat + "\n", "Sigmas: ");
    for (int i = 0; i < P.getRowDimension(); i++) {
        logStream.format(Locale.US, strFormat + numFormat + "\n", paramNames[i], sigmas[i]);
    }
    logStream.println("");
}

Example 34 with ParameterDriver

use of org.orekit.utils.ParameterDriver in project Orekit by CS-SI.

the class KalmanOrbitDeterminationTest method createPropagatorBuilder.

/**
 * Create a propagator builder from input parameters
 * @param parser input file parser
 * @param conventions IERS conventions to use
 * @param gravityField gravity field
 * @param body central body
 * @param orbit first orbit estimate
 * @return propagator builder
 * @throws NoSuchElementException if input parameters are missing
 * @throws OrekitException if body frame cannot be created
 */
private NumericalPropagatorBuilder createPropagatorBuilder(final KeyValueFileParser<ParameterKey> parser, final IERSConventions conventions, final NormalizedSphericalHarmonicsProvider gravityField, final OneAxisEllipsoid body, final Orbit orbit) throws NoSuchElementException, OrekitException {
    final double minStep;
    if (!parser.containsKey(ParameterKey.PROPAGATOR_MIN_STEP)) {
        minStep = 0.001;
    } else {
        minStep = parser.getDouble(ParameterKey.PROPAGATOR_MIN_STEP);
    }
    final double maxStep;
    if (!parser.containsKey(ParameterKey.PROPAGATOR_MAX_STEP)) {
        maxStep = 300;
    } else {
        maxStep = parser.getDouble(ParameterKey.PROPAGATOR_MAX_STEP);
    }
    final double dP;
    if (!parser.containsKey(ParameterKey.PROPAGATOR_POSITION_ERROR)) {
        dP = 10.0;
    } else {
        dP = parser.getDouble(ParameterKey.PROPAGATOR_POSITION_ERROR);
    }
    final double positionScale;
    if (!parser.containsKey(ParameterKey.ESTIMATOR_ORBITAL_PARAMETERS_POSITION_SCALE)) {
        positionScale = dP;
    } else {
        positionScale = parser.getDouble(ParameterKey.ESTIMATOR_ORBITAL_PARAMETERS_POSITION_SCALE);
    }
    final NumericalPropagatorBuilder propagatorBuilder = new NumericalPropagatorBuilder(orbit, new DormandPrince853IntegratorBuilder(minStep, maxStep, dP), PositionAngle.MEAN, positionScale);
    // initial mass
    final double mass;
    if (!parser.containsKey(ParameterKey.MASS)) {
        mass = 1000.0;
    } else {
        mass = parser.getDouble(ParameterKey.MASS);
    }
    propagatorBuilder.setMass(mass);
    // gravity field force model
    propagatorBuilder.addForceModel(new HolmesFeatherstoneAttractionModel(body.getBodyFrame(), gravityField));
    // ocean tides force model
    if (parser.containsKey(ParameterKey.OCEAN_TIDES_DEGREE) && parser.containsKey(ParameterKey.OCEAN_TIDES_ORDER)) {
        final int degree = parser.getInt(ParameterKey.OCEAN_TIDES_DEGREE);
        final int order = parser.getInt(ParameterKey.OCEAN_TIDES_ORDER);
        if (degree > 0 && order > 0) {
            propagatorBuilder.addForceModel(new OceanTides(body.getBodyFrame(), gravityField.getAe(), gravityField.getMu(), degree, order, conventions, TimeScalesFactory.getUT1(conventions, true)));
        }
    }
    // solid tides force model
    List<CelestialBody> solidTidesBodies = new ArrayList<CelestialBody>();
    if (parser.containsKey(ParameterKey.SOLID_TIDES_SUN) && parser.getBoolean(ParameterKey.SOLID_TIDES_SUN)) {
        solidTidesBodies.add(CelestialBodyFactory.getSun());
    }
    if (parser.containsKey(ParameterKey.SOLID_TIDES_MOON) && parser.getBoolean(ParameterKey.SOLID_TIDES_MOON)) {
        solidTidesBodies.add(CelestialBodyFactory.getMoon());
    }
    if (!solidTidesBodies.isEmpty()) {
        propagatorBuilder.addForceModel(new SolidTides(body.getBodyFrame(), gravityField.getAe(), gravityField.getMu(), gravityField.getTideSystem(), conventions, TimeScalesFactory.getUT1(conventions, true), solidTidesBodies.toArray(new CelestialBody[solidTidesBodies.size()])));
    }
    // third body attraction
    if (parser.containsKey(ParameterKey.THIRD_BODY_SUN) && parser.getBoolean(ParameterKey.THIRD_BODY_SUN)) {
        propagatorBuilder.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getSun()));
    }
    if (parser.containsKey(ParameterKey.THIRD_BODY_MOON) && parser.getBoolean(ParameterKey.THIRD_BODY_MOON)) {
        propagatorBuilder.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getMoon()));
    }
    // drag
    if (parser.containsKey(ParameterKey.DRAG) && parser.getBoolean(ParameterKey.DRAG)) {
        final double cd = parser.getDouble(ParameterKey.DRAG_CD);
        final double area = parser.getDouble(ParameterKey.DRAG_AREA);
        final boolean cdEstimated = parser.getBoolean(ParameterKey.DRAG_CD_ESTIMATED);
        MarshallSolarActivityFutureEstimation msafe = new MarshallSolarActivityFutureEstimation("(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\\p{Digit}\\p{Digit}\\p{Digit}\\p{Digit}F10\\.(?:txt|TXT)", MarshallSolarActivityFutureEstimation.StrengthLevel.AVERAGE);
        DataProvidersManager manager = DataProvidersManager.getInstance();
        manager.feed(msafe.getSupportedNames(), msafe);
        Atmosphere atmosphere = new DTM2000(msafe, CelestialBodyFactory.getSun(), body);
        propagatorBuilder.addForceModel(new DragForce(atmosphere, new IsotropicDrag(area, cd)));
        if (cdEstimated) {
            for (final ParameterDriver driver : propagatorBuilder.getPropagationParametersDrivers().getDrivers()) {
                if (driver.getName().equals(DragSensitive.DRAG_COEFFICIENT)) {
                    driver.setSelected(true);
                }
            }
        }
    }
    // solar radiation pressure
    if (parser.containsKey(ParameterKey.SOLAR_RADIATION_PRESSURE) && parser.getBoolean(ParameterKey.SOLAR_RADIATION_PRESSURE)) {
        final double cr = parser.getDouble(ParameterKey.SOLAR_RADIATION_PRESSURE_CR);
        final double area = parser.getDouble(ParameterKey.SOLAR_RADIATION_PRESSURE_AREA);
        final boolean cREstimated = parser.getBoolean(ParameterKey.SOLAR_RADIATION_PRESSURE_CR_ESTIMATED);
        propagatorBuilder.addForceModel(new SolarRadiationPressure(CelestialBodyFactory.getSun(), body.getEquatorialRadius(), new IsotropicRadiationSingleCoefficient(area, cr)));
        if (cREstimated) {
            for (final ParameterDriver driver : propagatorBuilder.getPropagationParametersDrivers().getDrivers()) {
                if (driver.getName().equals(RadiationSensitive.REFLECTION_COEFFICIENT)) {
                    driver.setSelected(true);
                }
            }
        }
    }
    // post-Newtonian correction force due to general relativity
    if (parser.containsKey(ParameterKey.GENERAL_RELATIVITY) && parser.getBoolean(ParameterKey.GENERAL_RELATIVITY)) {
        propagatorBuilder.addForceModel(new Relativity(gravityField.getMu()));
    }
    // extra polynomial accelerations
    if (parser.containsKey(ParameterKey.POLYNOMIAL_ACCELERATION_NAME)) {
        final String[] names = parser.getStringArray(ParameterKey.POLYNOMIAL_ACCELERATION_NAME);
        final Vector3D[] directions = parser.getVectorArray(ParameterKey.POLYNOMIAL_ACCELERATION_DIRECTION_X, ParameterKey.POLYNOMIAL_ACCELERATION_DIRECTION_Y, ParameterKey.POLYNOMIAL_ACCELERATION_DIRECTION_Z);
        final List<String>[] coefficients = parser.getStringsListArray(ParameterKey.POLYNOMIAL_ACCELERATION_COEFFICIENTS, ',');
        final boolean[] estimated = parser.getBooleanArray(ParameterKey.POLYNOMIAL_ACCELERATION_ESTIMATED);
        for (int i = 0; i < names.length; ++i) {
            final PolynomialParametricAcceleration ppa = new PolynomialParametricAcceleration(directions[i], true, names[i], null, coefficients[i].size() - 1);
            for (int k = 0; k < coefficients[i].size(); ++k) {
                final ParameterDriver driver = ppa.getParameterDriver(names[i] + "[" + k + "]");
                driver.setValue(Double.parseDouble(coefficients[i].get(k)));
                driver.setSelected(estimated[i]);
            }
            propagatorBuilder.addForceModel(ppa);
        }
    }
    return propagatorBuilder;
}

Example 35 with ParameterDriver

use of org.orekit.utils.ParameterDriver 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);
}