Examples with DSSTAtmosphericDrag org.orekit.propagation.semianalytical.dsst.forces.DSSTAtmosphericDrag used on opensource projects

Example 6 with DSSTAtmosphericDrag

use of org.orekit.propagation.semianalytical.dsst.forces.DSSTAtmosphericDrag in project Orekit by CS-SI.

the class DSSTPropagatorTest method testShortPeriodCoefficients.

@Test
public void testShortPeriodCoefficients() throws OrekitException {
    Utils.setDataRoot("regular-data:potential/icgem-format");
    GravityFieldFactory.addPotentialCoefficientsReader(new ICGEMFormatReader("^eigen-6s-truncated$", false));
    UnnormalizedSphericalHarmonicsProvider nshp = GravityFieldFactory.getUnnormalizedProvider(4, 4);
    Orbit orbit = new KeplerianOrbit(13378000, 0.05, 0, 0, FastMath.PI, 0, PositionAngle.MEAN, FramesFactory.getTOD(false), new AbsoluteDate(2003, 5, 6, TimeScalesFactory.getUTC()), nshp.getMu());
    double period = orbit.getKeplerianPeriod();
    double[][] tolerance = DSSTPropagator.tolerances(1.0, orbit);
    AdaptiveStepsizeIntegrator integrator = new DormandPrince853Integrator(period / 100, period * 100, tolerance[0], tolerance[1]);
    integrator.setInitialStepSize(10 * period);
    DSSTPropagator propagator = new DSSTPropagator(integrator, false);
    OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getGTOD(false));
    CelestialBody sun = CelestialBodyFactory.getSun();
    CelestialBody moon = CelestialBodyFactory.getMoon();
    propagator.addForceModel(new DSSTZonal(nshp, 4, 3, 9));
    propagator.addForceModel(new DSSTTesseral(earth.getBodyFrame(), Constants.WGS84_EARTH_ANGULAR_VELOCITY, nshp, 4, 4, 4, 8, 4, 4, 2));
    propagator.addForceModel(new DSSTThirdBody(sun));
    propagator.addForceModel(new DSSTThirdBody(moon));
    propagator.addForceModel(new DSSTAtmosphericDrag(new HarrisPriester(sun, earth), 2.1, 180));
    propagator.addForceModel(new DSSTSolarRadiationPressure(1.2, 180, sun, earth.getEquatorialRadius()));
    final AbsoluteDate finalDate = orbit.getDate().shiftedBy(30 * Constants.JULIAN_DAY);
    propagator.resetInitialState(new SpacecraftState(orbit, 45.0));
    final SpacecraftState stateNoConfig = propagator.propagate(finalDate);
    Assert.assertEquals(0, stateNoConfig.getAdditionalStates().size());
    propagator.setSelectedCoefficients(new HashSet<String>());
    propagator.resetInitialState(new SpacecraftState(orbit, 45.0));
    final SpacecraftState stateConfigEmpty = propagator.propagate(finalDate);
    Assert.assertEquals(234, stateConfigEmpty.getAdditionalStates().size());
    final Set<String> selected = new HashSet<String>();
    selected.add("DSST-3rd-body-Moon-s[7]");
    selected.add("DSST-central-body-tesseral-c[-2][3]");
    propagator.setSelectedCoefficients(selected);
    propagator.resetInitialState(new SpacecraftState(orbit, 45.0));
    final SpacecraftState stateConfigeSelected = propagator.propagate(finalDate);
    Assert.assertEquals(selected.size(), stateConfigeSelected.getAdditionalStates().size());
    propagator.setSelectedCoefficients(null);
    propagator.resetInitialState(new SpacecraftState(orbit, 45.0));
    final SpacecraftState stateConfigNull = propagator.propagate(finalDate);
    Assert.assertEquals(0, stateConfigNull.getAdditionalStates().size());
}

Example 7 with DSSTAtmosphericDrag

use of org.orekit.propagation.semianalytical.dsst.forces.DSSTAtmosphericDrag in project Orekit by CS-SI.

the class DSSTPropagatorTest method testPropagationWithDrag.

@Test
public void testPropagationWithDrag() throws OrekitException {
    // Central Body geopotential 2x0
    final UnnormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getUnnormalizedProvider(2, 0);
    final Frame earthFrame = CelestialBodyFactory.getEarth().getBodyOrientedFrame();
    DSSTForceModel zonal = new DSSTZonal(provider, 2, 0, 5);
    DSSTForceModel tesseral = new DSSTTesseral(earthFrame, Constants.WGS84_EARTH_ANGULAR_VELOCITY, provider, 2, 0, 0, 2, 2, 0, 0);
    // Drag Force Model
    final OneAxisEllipsoid earth = new OneAxisEllipsoid(provider.getAe(), Constants.WGS84_EARTH_FLATTENING, earthFrame);
    final Atmosphere atm = new HarrisPriester(CelestialBodyFactory.getSun(), earth, 6);
    final double cd = 2.0;
    final double area = 25.0;
    DSSTForceModel drag = new DSSTAtmosphericDrag(atm, cd, area);
    // LEO Orbit
    final AbsoluteDate initDate = new AbsoluteDate(2003, 7, 1, 0, 0, 00.000, TimeScalesFactory.getUTC());
    final Orbit orbit = new KeplerianOrbit(7204535.848109440, 0.0012402238462686, FastMath.toRadians(98.74341600466740), FastMath.toRadians(111.1990175076630), FastMath.toRadians(43.32990110790340), FastMath.toRadians(68.66852509725620), PositionAngle.MEAN, FramesFactory.getEME2000(), initDate, provider.getMu());
    // Set propagator with state and force model
    setDSSTProp(new SpacecraftState(orbit));
    dsstProp.addForceModel(zonal);
    dsstProp.addForceModel(tesseral);
    dsstProp.addForceModel(drag);
    // 5 days propagation
    final SpacecraftState state = dsstProp.propagate(initDate.shiftedBy(5. * 86400.));
    // Ref Standalone_DSST:
    // a    = 7204521.657141485 m
    // h/ey =  0.0007093755541595772
    // k/ex = -0.001016800430994036
    // p/hy =  0.8698955648709271
    // q/hx =  0.7757573478894775
    // lM   = 193°0939742953394
    Assert.assertEquals(7204521.657141485, state.getA(), 6.e-1);
    Assert.assertEquals(-0.001016800430994036, state.getEquinoctialEx(), 5.e-8);
    Assert.assertEquals(0.0007093755541595772, state.getEquinoctialEy(), 2.e-8);
    Assert.assertEquals(0.7757573478894775, state.getHx(), 5.e-8);
    Assert.assertEquals(0.8698955648709271, state.getHy(), 5.e-8);
    Assert.assertEquals(193.0939742953394, FastMath.toDegrees(MathUtils.normalizeAngle(state.getLM(), FastMath.PI)), 2.e-3);
    // Assert.assertEquals(((DSSTAtmosphericDrag)drag).getCd(), cd, 1e-9);
    // Assert.assertEquals(((DSSTAtmosphericDrag)drag).getArea(), area, 1e-9);
    Assert.assertEquals(((DSSTAtmosphericDrag) drag).getAtmosphere(), atm);
    // DSSTAtmosphericDrag.ATMOSPHERE_ALTITUDE_MAX
    final double atmosphericMaxConstant = 1000000.0;
    Assert.assertEquals(((DSSTAtmosphericDrag) drag).getRbar(), atmosphericMaxConstant + Constants.WGS84_EARTH_EQUATORIAL_RADIUS, 1e-9);
}