Examples with IsotropicDrag org.orekit.forces.drag.IsotropicDrag used on opensource projects

Example 11 with IsotropicDrag

use of org.orekit.forces.drag.IsotropicDrag in project Orekit by CS-SI.

the class NumericalConverterTest method setUp.

@Before
public void setUp() throws OrekitException, IOException, ParseException {
    Utils.setDataRoot("regular-data:potential/shm-format");
    gravity = new HolmesFeatherstoneAttractionModel(FramesFactory.getITRF(IERSConventions.IERS_2010, true), GravityFieldFactory.getNormalizedProvider(2, 0));
    mu = gravity.getParameterDriver(NewtonianAttraction.CENTRAL_ATTRACTION_COEFFICIENT).getValue();
    minStep = 1.0;
    maxStep = 600.0;
    dP = 10.0;
    // use a orbit that comes close to Earth so the drag coefficient has an effect
    final Vector3D position = new Vector3D(7.0e6, 1.0e6, 4.0e6).normalize().scalarMultiply(Constants.WGS84_EARTH_EQUATORIAL_RADIUS + 300e3);
    final Vector3D velocity = new Vector3D(-500.0, 8000.0, 1000.0);
    final AbsoluteDate initDate = new AbsoluteDate(2010, 10, 10, 10, 10, 10.0, TimeScalesFactory.getUTC());
    orbit = new EquinoctialOrbit(new PVCoordinates(position, velocity), FramesFactory.getEME2000(), initDate, mu);
    final double[][] tol = NumericalPropagator.tolerances(dP, orbit, OrbitType.CARTESIAN);
    propagator = new NumericalPropagator(new DormandPrince853Integrator(minStep, maxStep, tol[0], tol[1]));
    propagator.setInitialState(new SpacecraftState(orbit));
    propagator.setOrbitType(OrbitType.CARTESIAN);
    final OneAxisEllipsoid earth = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
    earth.setAngularThreshold(1.e-7);
    atmosphere = new SimpleExponentialAtmosphere(earth, 0.0004, 42000.0, 7500.0);
    final double dragCoef = 2.0;
    crossSection = 10.0;
    drag = new DragForce(atmosphere, new IsotropicDrag(crossSection, dragCoef));
    propagator.addForceModel(gravity);
    propagator.addForceModel(drag);
}

Example 12 with IsotropicDrag

use of org.orekit.forces.drag.IsotropicDrag in project Orekit by CS-SI.

the class OrbitDetermination 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 13 with IsotropicDrag

use of org.orekit.forces.drag.IsotropicDrag in project Orekit by CS-SI.

the class DSSTPropagation method setForceModel.

/**
 * Set numerical propagator force models
 *
 *  @param parser  input file parser
 *  @param normalized spherical harmonics provider
 *  @param earthFrame Earth rotating frame
 *  @param numProp numerical propagator
 *  @throws IOException
 *  @throws OrekitException
 */
private void setForceModel(final KeyValueFileParser<ParameterKey> parser, final NormalizedSphericalHarmonicsProvider normalized, final Frame earthFrame, final NumericalPropagator numProp) throws IOException, OrekitException {
    final double ae = normalized.getAe();
    final int degree = parser.getInt(ParameterKey.CENTRAL_BODY_DEGREE);
    final int order = parser.getInt(ParameterKey.CENTRAL_BODY_ORDER);
    if (order > degree) {
        throw new IOException("Potential order cannot be higher than potential degree");
    }
    // Central Body (normalized coefficients)
    numProp.addForceModel(new HolmesFeatherstoneAttractionModel(earthFrame, normalized));
    // 3rd body (SUN)
    if (parser.containsKey(ParameterKey.THIRD_BODY_SUN) && parser.getBoolean(ParameterKey.THIRD_BODY_SUN)) {
        numProp.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getSun()));
    }
    // 3rd body (MOON)
    if (parser.containsKey(ParameterKey.THIRD_BODY_MOON) && parser.getBoolean(ParameterKey.THIRD_BODY_MOON)) {
        numProp.addForceModel(new ThirdBodyAttraction(CelestialBodyFactory.getMoon()));
    }
    // Drag
    if (parser.containsKey(ParameterKey.DRAG) && parser.getBoolean(ParameterKey.DRAG)) {
        final OneAxisEllipsoid earth = new OneAxisEllipsoid(ae, Constants.WGS84_EARTH_FLATTENING, earthFrame);
        final Atmosphere atm = new HarrisPriester(CelestialBodyFactory.getSun(), earth, 6);
        final DragSensitive ssc = new IsotropicDrag(parser.getDouble(ParameterKey.DRAG_SF), parser.getDouble(ParameterKey.DRAG_CD));
        numProp.addForceModel(new DragForce(atm, ssc));
    }
    // 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 RadiationSensitive ssc = new IsotropicRadiationSingleCoefficient(parser.getDouble(ParameterKey.SOLAR_RADIATION_PRESSURE_SF), cR);
        numProp.addForceModel(new SolarRadiationPressure(CelestialBodyFactory.getSun(), ae, ssc));
    }
}