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

Example 11 with Orbit

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

the class HolmesFeatherstoneAttractionModelTest method testCompleteWithCunninghamReference.

@Test
@Deprecated
public void testCompleteWithCunninghamReference() throws OrekitException {
    Utils.setDataRoot("regular-data:potential/grgs-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new GRGSFormatReader("grim4s4_gr", true));
    // initialization
    AbsoluteDate date = new AbsoluteDate(new DateComponents(2000, 07, 01), new TimeComponents(13, 59, 27.816), TimeScalesFactory.getUTC());
    double i = FastMath.toRadians(98.7);
    double omega = FastMath.toRadians(93.0);
    double OMEGA = FastMath.toRadians(15.0 * 22.5);
    Orbit orbit = new KeplerianOrbit(7201009.7124401, 1e-3, i, omega, OMEGA, 0, PositionAngle.MEAN, FramesFactory.getEME2000(), date, mu);
    double[][] tolerances = NumericalPropagator.tolerances(0.01, orbit, OrbitType.CARTESIAN);
    AbsoluteDate targetDate = date.shiftedBy(3 * Constants.JULIAN_DAY);
    propagator = new NumericalPropagator(new DormandPrince853Integrator(1.0e-3, 120, tolerances[0], tolerances[1]));
    propagator.setOrbitType(OrbitType.CARTESIAN);
    propagator.addForceModel(new HolmesFeatherstoneAttractionModel(itrf, GravityFieldFactory.getNormalizedProvider(69, 69)));
    propagator.setInitialState(new SpacecraftState(orbit));
    SpacecraftState hfOrb = propagator.propagate(targetDate);
    propagator.removeForceModels();
    propagator.addForceModel(new CunninghamAttractionModel(itrf, GravityFieldFactory.getUnnormalizedProvider(69, 69)));
    propagator.setInitialState(new SpacecraftState(orbit));
    SpacecraftState cOrb = propagator.propagate(targetDate);
    Vector3D dif = hfOrb.getPVCoordinates().getPosition().subtract(cOrb.getPVCoordinates().getPosition());
    Assert.assertEquals(0, dif.getNorm(), 4e-5);
}

Example 12 with Orbit

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

the class OceanTidesTest method testDefaultInterpolation.

@Test
public void testDefaultInterpolation() throws OrekitException {
    IERSConventions conventions = IERSConventions.IERS_2010;
    Frame eme2000 = FramesFactory.getEME2000();
    Frame itrf = FramesFactory.getITRF(conventions, true);
    TimeScale utc = TimeScalesFactory.getUTC();
    UT1Scale ut1 = TimeScalesFactory.getUT1(conventions, true);
    AstronomicalAmplitudeReader aaReader = new AstronomicalAmplitudeReader("hf-fes2004.dat", 5, 2, 3, 1.0);
    DataProvidersManager.getInstance().feed(aaReader.getSupportedNames(), aaReader);
    Map<Integer, Double> map = aaReader.getAstronomicalAmplitudesMap();
    GravityFieldFactory.addOceanTidesReader(new FESCHatEpsilonReader("fes2004-7x7.dat", 0.01, FastMath.toRadians(1.0), OceanLoadDeformationCoefficients.IERS_2010, map));
    NormalizedSphericalHarmonicsProvider gravityField = GravityFieldFactory.getConstantNormalizedProvider(5, 5);
    // initialization
    AbsoluteDate date = new AbsoluteDate(1970, 07, 01, 13, 59, 27.816, 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, gravityField.getMu());
    AbsoluteDate target = date.shiftedBy(7 * Constants.JULIAN_DAY);
    ForceModel hf = new HolmesFeatherstoneAttractionModel(itrf, gravityField);
    SpacecraftState raw = propagate(orbit, target, hf, new OceanTides(itrf, gravityField.getAe(), gravityField.getMu(), true, Double.NaN, -1, 6, 6, conventions, ut1));
    SpacecraftState interpolated = propagate(orbit, target, hf, new OceanTides(itrf, gravityField.getAe(), gravityField.getMu(), 6, 6, IERSConventions.IERS_2010, ut1));
    Assert.assertEquals(0.0, Vector3D.distance(raw.getPVCoordinates().getPosition(), interpolated.getPVCoordinates().getPosition()), // threshold would be 3.4e-5 for 30 days propagation
    9.9e-6);
}

Example 13 with Orbit

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

the class OrbitDeterminationTest method run.

private ResultOD run(final File input, final boolean print) throws IOException, IllegalArgumentException, OrekitException, ParseException {
    // read input parameters
    KeyValueFileParser<ParameterKey> parser = new KeyValueFileParser<ParameterKey>(ParameterKey.class);
    parser.parseInput(input.getAbsolutePath(), new FileInputStream(input));
    // log file
    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
    final Orbit initialGuess = createOrbit(parser, gravityField.getMu());
    // 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);
    // estimator
    final BatchLSEstimator estimator = createEstimator(parser, propagatorBuilder);
    // 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)));
    }
    for (ObservedMeasurement<?> measurement : measurements) {
        estimator.addMeasurement(measurement);
    }
    if (print) {
        estimator.setObserver(new BatchLSObserver() {

            private PVCoordinates previousPV;

            {
                previousPV = initialGuess.getPVCoordinates();
                final String header = "iteration evaluations      ΔP(m)        ΔV(m/s)           RMS          nb Range    nb Range-rate  nb Angular     nb PV%n";
                System.out.format(Locale.US, header);
            }

            /**
             * {@inheritDoc}
             */
            @Override
            public void evaluationPerformed(final int iterationsCount, final int evaluationsCount, final Orbit[] orbits, final ParameterDriversList estimatedOrbitalParameters, final ParameterDriversList estimatedPropagatorParameters, final ParameterDriversList estimatedMeasurementsParameters, final EstimationsProvider evaluationsProvider, final LeastSquaresProblem.Evaluation lspEvaluation) {
                PVCoordinates currentPV = orbits[0].getPVCoordinates();
                final String format0 = "    %2d         %2d                                 %16.12f     %s       %s     %s     %s%n";
                final String format = "    %2d         %2d      %13.6f %12.9f %16.12f     %s       %s     %s     %s%n";
                final EvaluationCounter<Range> rangeCounter = new EvaluationCounter<Range>();
                final EvaluationCounter<RangeRate> rangeRateCounter = new EvaluationCounter<RangeRate>();
                final EvaluationCounter<AngularAzEl> angularCounter = new EvaluationCounter<AngularAzEl>();
                final EvaluationCounter<PV> pvCounter = new EvaluationCounter<PV>();
                for (final Map.Entry<ObservedMeasurement<?>, EstimatedMeasurement<?>> entry : estimator.getLastEstimations().entrySet()) {
                    if (entry.getKey() instanceof Range) {
                        @SuppressWarnings("unchecked") EstimatedMeasurement<Range> evaluation = (EstimatedMeasurement<Range>) entry.getValue();
                        rangeCounter.add(evaluation);
                    } else if (entry.getKey() instanceof RangeRate) {
                        @SuppressWarnings("unchecked") EstimatedMeasurement<RangeRate> evaluation = (EstimatedMeasurement<RangeRate>) entry.getValue();
                        rangeRateCounter.add(evaluation);
                    } else if (entry.getKey() instanceof AngularAzEl) {
                        @SuppressWarnings("unchecked") EstimatedMeasurement<AngularAzEl> evaluation = (EstimatedMeasurement<AngularAzEl>) entry.getValue();
                        angularCounter.add(evaluation);
                    } else if (entry.getKey() instanceof PV) {
                        @SuppressWarnings("unchecked") EstimatedMeasurement<PV> evaluation = (EstimatedMeasurement<PV>) entry.getValue();
                        pvCounter.add(evaluation);
                    }
                }
                if (evaluationsCount == 1) {
                    System.out.format(Locale.US, format0, iterationsCount, evaluationsCount, lspEvaluation.getRMS(), rangeCounter.format(8), rangeRateCounter.format(8), angularCounter.format(8), pvCounter.format(8));
                } else {
                    System.out.format(Locale.US, format, iterationsCount, evaluationsCount, Vector3D.distance(previousPV.getPosition(), currentPV.getPosition()), Vector3D.distance(previousPV.getVelocity(), currentPV.getVelocity()), lspEvaluation.getRMS(), rangeCounter.format(8), rangeRateCounter.format(8), angularCounter.format(8), pvCounter.format(8));
                }
                previousPV = currentPV;
            }
        });
    }
    Orbit estimated = estimator.estimate()[0].getInitialState().getOrbit();
    // compute some statistics
    for (final Map.Entry<ObservedMeasurement<?>, EstimatedMeasurement<?>> entry : estimator.getLastEstimations().entrySet()) {
        if (entry.getKey() instanceof Range) {
            @SuppressWarnings("unchecked") EstimatedMeasurement<Range> evaluation = (EstimatedMeasurement<Range>) entry.getValue();
            rangeLog.add(evaluation);
        } else if (entry.getKey() instanceof RangeRate) {
            @SuppressWarnings("unchecked") EstimatedMeasurement<RangeRate> evaluation = (EstimatedMeasurement<RangeRate>) entry.getValue();
            rangeRateLog.add(evaluation);
        } else if (entry.getKey() instanceof AngularAzEl) {
            @SuppressWarnings("unchecked") EstimatedMeasurement<AngularAzEl> evaluation = (EstimatedMeasurement<AngularAzEl>) entry.getValue();
            azimuthLog.add(evaluation);
            elevationLog.add(evaluation);
        } else if (entry.getKey() instanceof PV) {
            @SuppressWarnings("unchecked") EstimatedMeasurement<PV> evaluation = (EstimatedMeasurement<PV>) entry.getValue();
            positionLog.add(evaluation);
            velocityLog.add(evaluation);
        }
    }
    // parmaters and measurements.
    final ParameterDriversList propagatorParameters = estimator.getPropagatorParametersDrivers(true);
    final ParameterDriversList measurementsParameters = estimator.getMeasurementsParametersDrivers(true);
    // instation of results
    return new ResultOD(propagatorParameters, measurementsParameters, estimator.getIterationsCount(), estimator.getEvaluationsCount(), estimated.getPVCoordinates(), rangeLog.createStatisticsSummary(), rangeRateLog.createStatisticsSummary(), azimuthLog.createStatisticsSummary(), elevationLog.createStatisticsSummary(), positionLog.createStatisticsSummary(), velocityLog.createStatisticsSummary(), estimator.getPhysicalCovariances(1.0e-10));
}

Example 14 with Orbit

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

the class InterSatellitesRangeTest method genericTestStateDerivatives.

void genericTestStateDerivatives(final boolean printResults, final int index, 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 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, propagatorBuilder);
    closePropagator.setEphemerisMode();
    closePropagator.propagate(context.initialOrbit.getDate().shiftedBy(3.5 * closeOrbit.getKeplerianPeriod()));
    final BoundedPropagator ephemeris = closePropagator.getGeneratedEphemeris();
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new InterSatellitesRangeMeasurementCreator(ephemeris), 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.)) {
                // 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.
                final double meanDelay = measurement.getObservedValue()[0] / Constants.SPEED_OF_LIGHT;
                final AbsoluteDate date = measurement.getDate().shiftedBy(-0.75 * meanDelay);
                final SpacecraftState[] states = { interpolator.getInterpolatedState(date), ephemeris.propagate(date) };
                final double[][] jacobian = measurement.estimate(0, 0, states).getStateDerivatives(index);
                // 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 {
                        final SpacecraftState[] s = states.clone();
                        s[index] = state;
                        return measurement.estimate(0, 0, s).getEstimatedValue();
                    }
                }, measurement.getDimension(), propagator.getAttitudeProvider(), OrbitType.CARTESIAN, PositionAngle.TRUE, 2.0, 3).value(states[index]);
                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) {
                    System.out.format(Locale.US, "%-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", 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, "%-23s  %-23s  " + "%10s  %10s  %10s  " + "%10s  %10s  %10s  " + "%10s  %10s  %10s  " + "%10s  %10s  %10s%n", "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);
}

Example 15 with Orbit

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

the class InterSatellitesRangeTest method genericTestValues.

/**
 * Generic test function for values of the inter-satellites range
 * @param printResults Print the results ?
 * @throws OrekitException
 */
void genericTestValues(final boolean printResults) 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 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, propagatorBuilder);
    closePropagator.setEphemerisMode();
    closePropagator.propagate(context.initialOrbit.getDate().shiftedBy(3.5 * closeOrbit.getKeplerianPeriod()));
    final BoundedPropagator ephemeris = closePropagator.getGeneratedEphemeris();
    final Propagator propagator = EstimationTestUtils.createPropagator(context.initialOrbit, propagatorBuilder);
    final List<ObservedMeasurement<?>> measurements = EstimationTestUtils.createMeasurements(propagator, new InterSatellitesRangeMeasurementCreator(ephemeris), 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> absoluteErrors = new ArrayList<Double>();
    final List<Double> relativeErrors = 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.)) {
                // 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.
                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);
                // Values of the Range & errors
                final double RangeObserved = measurement.getObservedValue()[0];
                final EstimatedMeasurement<?> estimated = measurement.estimate(0, 0, new SpacecraftState[] { state, ephemeris.propagate(state.getDate()) });
                // the real state used for estimation is adjusted according to downlink delay
                double adjustment = state.getDate().durationFrom(estimated.getStates()[0].getDate());
                Assert.assertTrue(adjustment > 0.000006);
                Assert.assertTrue(adjustment < 0.0003);
                final double RangeEstimated = estimated.getEstimatedValue()[0];
                final double absoluteError = RangeEstimated - RangeObserved;
                absoluteErrors.add(absoluteError);
                relativeErrors.add(FastMath.abs(absoluteError) / FastMath.abs(RangeObserved));
                // Print results on console ?
                if (printResults) {
                    final AbsoluteDate measurementDate = measurement.getDate();
                    System.out.format(Locale.US, "%-23s  %-23s  %19.6f  %19.6f  %13.6e  %13.6e%n", measurementDate, date, RangeObserved, RangeEstimated, FastMath.abs(RangeEstimated - RangeObserved), FastMath.abs((RangeEstimated - RangeObserved) / RangeObserved));
                }
            }
        // End if measurement date between previous and current interpolator step
        }
    // End for loop on the measurements
    });
    // Print results on console ? Header
    if (printResults) {
        System.out.format(Locale.US, "%-23s  %-23s  %19s  %19s  %13s  %13s%n", "Measurement Date", "State Date", "Range observed [m]", "Range estimated [m]", "ΔRange [m]", "rel ΔRange");
    }
    // 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 array
    final double[] absErrors = absoluteErrors.stream().mapToDouble(Double::doubleValue).toArray();
    final double[] relErrors = relativeErrors.stream().mapToDouble(Double::doubleValue).toArray();
    // Statistics' assertion
    final double absErrorsMedian = new Median().evaluate(absErrors);
    final double absErrorsMin = new Min().evaluate(absErrors);
    final double absErrorsMax = new Max().evaluate(absErrors);
    final double relErrorsMedian = new Median().evaluate(relErrors);
    final double relErrorsMax = new Max().evaluate(relErrors);
    // Print the results on console ? Final results
    if (printResults) {
        System.out.println();
        System.out.println("Absolute errors median: " + absErrorsMedian);
        System.out.println("Absolute errors min   : " + absErrorsMin);
        System.out.println("Absolute errors max   : " + absErrorsMax);
        System.out.println("Relative errors median: " + relErrorsMedian);
        System.out.println("Relative errors max   : " + relErrorsMax);
    }
    Assert.assertEquals(0.0, absErrorsMedian, 1.3e-7);
    Assert.assertEquals(0.0, absErrorsMin, 7.3e-7);
    Assert.assertEquals(0.0, absErrorsMax, 1.8e-7);
    Assert.assertEquals(0.0, relErrorsMedian, 1.0e-12);
    Assert.assertEquals(0.0, relErrorsMax, 3.2e-12);
}