Examples with LofOffset org.orekit.attitudes.LofOffset used on opensource projects

Example 51 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class AdapterPropagatorTest method testNonKeplerian.

@Test
public void testNonKeplerian() throws OrekitException, ParseException, IOException {
    Orbit leo = new CircularOrbit(7204319.233600575, 4.434564637450575E-4, 0.0011736728299091088, 1.7211611441767323, 5.5552084166959474, 24950.321259193086, PositionAngle.TRUE, FramesFactory.getEME2000(), new AbsoluteDate(new DateComponents(2003, 9, 16), new TimeComponents(23, 11, 20.264), TimeScalesFactory.getUTC()), Constants.EIGEN5C_EARTH_MU);
    double mass = 4093.0;
    AbsoluteDate t0 = new AbsoluteDate(new DateComponents(2003, 9, 16), new TimeComponents(23, 14, 40.264), TimeScalesFactory.getUTC());
    Vector3D dV = new Vector3D(0.0, 3.0, 0.0);
    double f = 40.0;
    double isp = 300.0;
    double vExhaust = Constants.G0_STANDARD_GRAVITY * isp;
    double dt = -(mass * vExhaust / f) * FastMath.expm1(-dV.getNorm() / vExhaust);
    // setup a specific coefficient file for gravity potential as it will also
    // try to read a corrupted one otherwise
    GravityFieldFactory.addPotentialCoefficientsReader(new ICGEMFormatReader("g007_eigen_05c_coef", false));
    NormalizedSphericalHarmonicsProvider gravityField = GravityFieldFactory.getNormalizedProvider(8, 8);
    BoundedPropagator withoutManeuver = getEphemeris(leo, mass, 10, new LofOffset(leo.getFrame(), LOFType.VNC), t0, Vector3D.ZERO, f, isp, true, true, gravityField);
    BoundedPropagator withManeuver = getEphemeris(leo, mass, 10, new LofOffset(leo.getFrame(), LOFType.VNC), t0, dV, f, isp, true, true, gravityField);
    // we set up a model that reverts the maneuvers
    AdapterPropagator adapterPropagator = new AdapterPropagator(withManeuver);
    SpacecraftState state0 = adapterPropagator.propagate(t0);
    AdapterPropagator.DifferentialEffect directEffect = new SmallManeuverAnalyticalModel(state0, dV.negate(), isp);
    AdapterPropagator.DifferentialEffect derivedEffect = new J2DifferentialEffect(state0, directEffect, false, GravityFieldFactory.getUnnormalizedProvider(gravityField));
    adapterPropagator.addEffect(directEffect);
    adapterPropagator.addEffect(derivedEffect);
    adapterPropagator.addAdditionalStateProvider(new AdditionalStateProvider() {

        public String getName() {
            return "dummy 3";
        }

        public double[] getAdditionalState(SpacecraftState state) {
            return new double[3];
        }
    });
    // the adapted propagators do not manage the additional states from the reference,
    // they simply forward them
    Assert.assertFalse(adapterPropagator.isAdditionalStateManaged("dummy 1"));
    Assert.assertFalse(adapterPropagator.isAdditionalStateManaged("dummy 2"));
    Assert.assertTrue(adapterPropagator.isAdditionalStateManaged("dummy 3"));
    double maxDelta = 0;
    double maxNominal = 0;
    for (AbsoluteDate t = t0.shiftedBy(0.5 * dt); t.compareTo(withoutManeuver.getMaxDate()) < 0; t = t.shiftedBy(600.0)) {
        PVCoordinates pvWithout = withoutManeuver.getPVCoordinates(t, leo.getFrame());
        PVCoordinates pvWith = withManeuver.getPVCoordinates(t, leo.getFrame());
        PVCoordinates pvReverted = adapterPropagator.getPVCoordinates(t, leo.getFrame());
        double nominal = new PVCoordinates(pvWithout, pvWith).getPosition().getNorm();
        double revertError = new PVCoordinates(pvWithout, pvReverted).getPosition().getNorm();
        maxDelta = FastMath.max(maxDelta, revertError);
        maxNominal = FastMath.max(maxNominal, nominal);
        Assert.assertEquals(2, adapterPropagator.propagate(t).getAdditionalState("dummy 1").length);
        Assert.assertEquals(1, adapterPropagator.propagate(t).getAdditionalState("dummy 2").length);
        Assert.assertEquals(3, adapterPropagator.propagate(t).getAdditionalState("dummy 3").length);
    }
    Assert.assertTrue(maxDelta < 120);
    Assert.assertTrue(maxNominal > 2800);
}

Example 52 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class AdapterPropagatorTest method testEccentricOrbit.

@Test
public void testEccentricOrbit() throws OrekitException, ParseException, IOException {
    Orbit heo = new KeplerianOrbit(90000000.0, 0.92, FastMath.toRadians(98.0), FastMath.toRadians(12.3456), FastMath.toRadians(123.456), FastMath.toRadians(1.23456), PositionAngle.MEAN, FramesFactory.getEME2000(), new AbsoluteDate(new DateComponents(2004, 01, 01), new TimeComponents(23, 30, 00.000), TimeScalesFactory.getUTC()), Constants.EIGEN5C_EARTH_MU);
    double mass = 5600.0;
    AbsoluteDate t0 = heo.getDate().shiftedBy(1000.0);
    Vector3D dV = new Vector3D(-0.01, 0.02, 0.03);
    double f = 20.0;
    double isp = 315.0;
    double vExhaust = Constants.G0_STANDARD_GRAVITY * isp;
    double dt = -(mass * vExhaust / f) * FastMath.expm1(-dV.getNorm() / vExhaust);
    BoundedPropagator withoutManeuver = getEphemeris(heo, mass, 5, new LofOffset(heo.getFrame(), LOFType.LVLH), t0, Vector3D.ZERO, f, isp, false, false, null);
    BoundedPropagator withManeuver = getEphemeris(heo, mass, 5, new LofOffset(heo.getFrame(), LOFType.LVLH), t0, dV, f, isp, false, false, null);
    // we set up a model that reverts the maneuvers
    AdapterPropagator adapterPropagator = new AdapterPropagator(withManeuver);
    AdapterPropagator.DifferentialEffect effect = new SmallManeuverAnalyticalModel(adapterPropagator.propagate(t0), dV.negate(), isp);
    adapterPropagator.addEffect(effect);
    adapterPropagator.addAdditionalStateProvider(new AdditionalStateProvider() {

        public String getName() {
            return "dummy 3";
        }

        public double[] getAdditionalState(SpacecraftState state) {
            return new double[3];
        }
    });
    // the adapted propagators do not manage the additional states from the reference,
    // they simply forward them
    Assert.assertFalse(adapterPropagator.isAdditionalStateManaged("dummy 1"));
    Assert.assertFalse(adapterPropagator.isAdditionalStateManaged("dummy 2"));
    Assert.assertTrue(adapterPropagator.isAdditionalStateManaged("dummy 3"));
    for (AbsoluteDate t = t0.shiftedBy(0.5 * dt); t.compareTo(withoutManeuver.getMaxDate()) < 0; t = t.shiftedBy(300.0)) {
        PVCoordinates pvWithout = withoutManeuver.getPVCoordinates(t, heo.getFrame());
        PVCoordinates pvReverted = adapterPropagator.getPVCoordinates(t, heo.getFrame());
        double revertError = Vector3D.distance(pvWithout.getPosition(), pvReverted.getPosition());
        Assert.assertEquals(0, revertError, 2.5e-5 * heo.getA());
        Assert.assertEquals(2, adapterPropagator.propagate(t).getAdditionalState("dummy 1").length);
        Assert.assertEquals(1, adapterPropagator.propagate(t).getAdditionalState("dummy 2").length);
        Assert.assertEquals(3, adapterPropagator.propagate(t).getAdditionalState("dummy 3").length);
    }
}

Example 53 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class EcksteinHechlerPropagatorTest method propagatedCartesian.

@Test
public void propagatedCartesian() throws OrekitException {
    // Definition of initial conditions with position and velocity
    // ------------------------------------------------------------
    // with e around e = 1.4e-4 and i = 1.7 rad
    Vector3D position = new Vector3D(3220103., 69623., 6449822.);
    Vector3D velocity = new Vector3D(6414.7, -2006., -3180.);
    AbsoluteDate initDate = AbsoluteDate.J2000_EPOCH.shiftedBy(584.);
    Orbit initialOrbit = new EquinoctialOrbit(new PVCoordinates(position, velocity), FramesFactory.getEME2000(), initDate, provider.getMu());
    // Extrapolator definition
    // -----------------------
    EcksteinHechlerPropagator extrapolator = new EcksteinHechlerPropagator(initialOrbit, new LofOffset(initialOrbit.getFrame(), LOFType.VNC, RotationOrder.XYZ, 0, 0, 0), provider);
    // Extrapolation at a final date different from initial date
    // ---------------------------------------------------------
    // extrapolation duration in seconds
    double delta_t = 100000.0;
    AbsoluteDate extrapDate = initDate.shiftedBy(delta_t);
    SpacecraftState finalOrbit = extrapolator.propagate(extrapDate);
    Assert.assertEquals(0.0, finalOrbit.getDate().durationFrom(extrapDate), 1.0e-9);
    // computation of M final orbit
    double LM = finalOrbit.getLE() - finalOrbit.getEquinoctialEx() * FastMath.sin(finalOrbit.getLE()) + finalOrbit.getEquinoctialEy() * FastMath.cos(finalOrbit.getLE());
    Assert.assertEquals(LM, finalOrbit.getLM(), Utils.epsilonAngle * FastMath.abs(finalOrbit.getLM()));
    // test of tan ((LE - Lv)/2) :
    Assert.assertEquals(FastMath.tan((finalOrbit.getLE() - finalOrbit.getLv()) / 2.), tangLEmLv(finalOrbit.getLv(), finalOrbit.getEquinoctialEx(), finalOrbit.getEquinoctialEy()), Utils.epsilonAngle);
    // test of evolution of M vs E: LM = LE - ex*sin(LE) + ey*cos(LE)
    double deltaM = finalOrbit.getLM() - initialOrbit.getLM();
    double deltaE = finalOrbit.getLE() - initialOrbit.getLE();
    double delta = finalOrbit.getEquinoctialEx() * FastMath.sin(finalOrbit.getLE()) - initialOrbit.getEquinoctialEx() * FastMath.sin(initialOrbit.getLE()) - finalOrbit.getEquinoctialEy() * FastMath.cos(finalOrbit.getLE()) + initialOrbit.getEquinoctialEy() * FastMath.cos(initialOrbit.getLE());
    Assert.assertEquals(deltaM, deltaE - delta, Utils.epsilonAngle * FastMath.abs(deltaE - delta));
    // for final orbit
    double ex = finalOrbit.getEquinoctialEx();
    double ey = finalOrbit.getEquinoctialEy();
    double hx = finalOrbit.getHx();
    double hy = finalOrbit.getHy();
    double LE = finalOrbit.getLE();
    double ex2 = ex * ex;
    double ey2 = ey * ey;
    double hx2 = hx * hx;
    double hy2 = hy * hy;
    double h2p1 = 1. + hx2 + hy2;
    double beta = 1. / (1. + FastMath.sqrt(1. - ex2 - ey2));
    double x3 = -ex + (1. - beta * ey2) * FastMath.cos(LE) + beta * ex * ey * FastMath.sin(LE);
    double y3 = -ey + (1. - beta * ex2) * FastMath.sin(LE) + beta * ex * ey * FastMath.cos(LE);
    Vector3D U = new Vector3D((1. + hx2 - hy2) / h2p1, (2. * hx * hy) / h2p1, (-2. * hy) / h2p1);
    Vector3D V = new Vector3D((2. * hx * hy) / h2p1, (1. - hx2 + hy2) / h2p1, (2. * hx) / h2p1);
    Vector3D r = new Vector3D(finalOrbit.getA(), (new Vector3D(x3, U, y3, V)));
    Assert.assertEquals(finalOrbit.getPVCoordinates().getPosition().getNorm(), r.getNorm(), Utils.epsilonTest * r.getNorm());
}

Example 54 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class EcksteinHechlerPropagatorTest method testIssue224Backward.

@Test
public void testIssue224Backward() throws OrekitException, IOException, ClassNotFoundException {
    AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(154.);
    Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    Frame eme2000 = FramesFactory.getEME2000();
    Vector3D pole = itrf.getTransformTo(eme2000, date).transformVector(Vector3D.PLUS_K);
    Frame poleAligned = new Frame(FramesFactory.getEME2000(), new Transform(date, new Rotation(pole, Vector3D.PLUS_K)), "pole aligned", true);
    CircularOrbit initial = new CircularOrbit(7208669.8179538045, 1.3740461966386876E-4, -3.2364250248363356E-5, FastMath.toRadians(97.40236024565775), FastMath.toRadians(166.15873160992115), FastMath.toRadians(90.1282370098961), PositionAngle.MEAN, poleAligned, date, provider.getMu());
    EcksteinHechlerPropagator propagator = new EcksteinHechlerPropagator(initial, new LofOffset(poleAligned, LOFType.VVLH), 1000.0, provider);
    propagator.addAdditionalStateProvider(new SevenProvider());
    propagator.setEphemerisMode();
    // Impulsive burns
    final AbsoluteDate burn1Date = initial.getDate().shiftedBy(-200);
    ImpulseManeuver<DateDetector> impulsiveBurn1 = new ImpulseManeuver<DateDetector>(new DateDetector(burn1Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn1);
    final AbsoluteDate burn2Date = initial.getDate().shiftedBy(-300);
    ImpulseManeuver<DateDetector> impulsiveBurn2 = new ImpulseManeuver<DateDetector>(new DateDetector(burn2Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn2);
    propagator.propagate(initial.getDate().shiftedBy(-400));
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    ObjectOutputStream oos = new ObjectOutputStream(bos);
    oos.writeObject(propagator.getGeneratedEphemeris());
    Assert.assertTrue(bos.size() > 2950);
    Assert.assertTrue(bos.size() < 3050);
    ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
    ObjectInputStream ois = new ObjectInputStream(bis);
    BoundedPropagator ephemeris = (BoundedPropagator) ois.readObject();
    ephemeris.setMasterMode(10, new OrekitFixedStepHandler() {

        public void handleStep(SpacecraftState currentState, boolean isLast) {
            if (currentState.getDate().durationFrom(burn1Date) > 0.001) {
                Assert.assertEquals(97.402, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn1Date) < -0.001 && currentState.getDate().durationFrom(burn2Date) > 0.001) {
                Assert.assertEquals(98.164, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn2Date) < -0.001) {
                Assert.assertEquals(99.273, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            }
        }
    });
    ephemeris.propagate(ephemeris.getMinDate());
}

Example 55 with LofOffset

use of org.orekit.attitudes.LofOffset in project Orekit by CS-SI.

the class EcksteinHechlerPropagatorTest method testIssue224Forward.

@Test
public void testIssue224Forward() throws OrekitException, IOException, ClassNotFoundException {
    AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(154.);
    Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
    Frame eme2000 = FramesFactory.getEME2000();
    Vector3D pole = itrf.getTransformTo(eme2000, date).transformVector(Vector3D.PLUS_K);
    Frame poleAligned = new Frame(FramesFactory.getEME2000(), new Transform(date, new Rotation(pole, Vector3D.PLUS_K)), "pole aligned", true);
    CircularOrbit initial = new CircularOrbit(7208669.8179538045, 1.3740461966386876E-4, -3.2364250248363356E-5, FastMath.toRadians(97.40236024565775), FastMath.toRadians(166.15873160992115), FastMath.toRadians(90.1282370098961), PositionAngle.MEAN, poleAligned, date, provider.getMu());
    EcksteinHechlerPropagator propagator = new EcksteinHechlerPropagator(initial, new LofOffset(poleAligned, LOFType.VVLH), 1000.0, provider);
    propagator.addAdditionalStateProvider(new SevenProvider());
    propagator.setEphemerisMode();
    // Impulsive burns
    final AbsoluteDate burn1Date = initial.getDate().shiftedBy(200);
    ImpulseManeuver<DateDetector> impulsiveBurn1 = new ImpulseManeuver<DateDetector>(new DateDetector(burn1Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn1);
    final AbsoluteDate burn2Date = initial.getDate().shiftedBy(300);
    ImpulseManeuver<DateDetector> impulsiveBurn2 = new ImpulseManeuver<DateDetector>(new DateDetector(burn2Date), new Vector3D(0.0, 500.0, 0.0), 320);
    propagator.addEventDetector(impulsiveBurn2);
    propagator.propagate(initial.getDate().shiftedBy(400));
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    ObjectOutputStream oos = new ObjectOutputStream(bos);
    oos.writeObject(propagator.getGeneratedEphemeris());
    Assert.assertTrue(bos.size() > 2950);
    Assert.assertTrue(bos.size() < 3050);
    ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
    ObjectInputStream ois = new ObjectInputStream(bis);
    BoundedPropagator ephemeris = (BoundedPropagator) ois.readObject();
    ephemeris.setMasterMode(10, new OrekitFixedStepHandler() {

        public void handleStep(SpacecraftState currentState, boolean isLast) {
            if (currentState.getDate().durationFrom(burn1Date) < -0.001) {
                Assert.assertEquals(97.402, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn1Date) > 0.001 && currentState.getDate().durationFrom(burn2Date) < -0.001) {
                Assert.assertEquals(98.183, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            } else if (currentState.getDate().durationFrom(burn2Date) > 0.001) {
                Assert.assertEquals(99.310, FastMath.toDegrees(currentState.getI()), 1.0e-3);
            }
        }
    });
    ephemeris.propagate(ephemeris.getMaxDate());
}