@Test
public void testGroundToGroundIssue181() throws OrekitException {
Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
Frame eme2000 = FramesFactory.getEME2000();
OneAxisEllipsoid model =
new OneAxisEllipsoid(
Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, itrf);
TimeStampedPVCoordinates initPV =
new TimeStampedPVCoordinates(
AbsoluteDate.J2000_EPOCH.shiftedBy(584.),
new Vector3D(3220103., 69623., 6449822.),
new Vector3D(6414.7, -2006., -3180.),
Vector3D.ZERO);
TimeStampedPVCoordinates body =
itrf.getTransformTo(eme2000, initPV.getDate()).transformPVCoordinates(initPV);
TimeStampedPVCoordinates ground1 = model.projectToGround(body, itrf);
TimeStampedPVCoordinates ground2 = model.projectToGround(ground1, itrf);
Assert.assertEquals(
0.0, Vector3D.distance(ground1.getPosition(), ground2.getPosition()), 1.0e-12);
Assert.assertEquals(
0.0, Vector3D.distance(ground1.getVelocity(), ground2.getVelocity()), 1.0e-12);
Assert.assertEquals(
0.0, Vector3D.distance(ground1.getAcceleration(), ground2.getAcceleration()), 1.0e-12);
}
private static List<GeodeticPoint> computeCircle(
double latitude,
double longitude,
double altitude,
String name,
double minElevation,
double radius,
int points)
throws OrekitException {
// define Earth shape, using WGS84 model
BodyShape earth =
new OneAxisEllipsoid(
Constants.WGS84_EARTH_EQUATORIAL_RADIUS,
Constants.WGS84_EARTH_FLATTENING,
FramesFactory.getITRF(IERSConventions.IERS_2010, false));
// define an array of ground stations
TopocentricFrame station =
new TopocentricFrame(earth, new GeodeticPoint(latitude, longitude, altitude), name);
// compute the visibility circle
List<GeodeticPoint> circle = new ArrayList<GeodeticPoint>();
for (int i = 0; i < points; ++i) {
double azimuth = i * (2.0 * FastMath.PI / points);
circle.add(station.computeLimitVisibilityPoint(radius, azimuth, minElevation));
}
// return the computed points
return circle;
}
@Test
public void testNoLineIntersection() throws OrekitException {
AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
Frame frame = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
OneAxisEllipsoid model = new OneAxisEllipsoid(100.0, 0.9, frame);
Vector3D point = new Vector3D(0.0, 93.7139699, 3.5930796);
Vector3D direction = new Vector3D(0.0, 9.0, -2.0);
Line line = new Line(point, point.add(direction), 1.0e-10);
Assert.assertNull(model.getIntersectionPoint(line, point, frame, date));
}
@Test
public void testFarPoint() throws OrekitException {
AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
Frame frame = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
OneAxisEllipsoid model = new OneAxisEllipsoid(90.0, 5.0 / 9.0, frame);
Vector3D point = new Vector3D(1.0e15, 2.0e15, -1.0e12);
GeodeticPoint gp = model.transform(point, frame, date);
Vector3D rebuilt = model.transform(gp);
Assert.assertEquals(0.0, rebuilt.distance(point), 1.0e-15 * point.getNorm());
}
@Test
public void testGeoCar() throws OrekitException {
OneAxisEllipsoid model =
new OneAxisEllipsoid(
6378137.0, 1.0 / 298.257222101, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
GeodeticPoint nsp = new GeodeticPoint(0.852479154923577, 0.0423149994747243, 111.6);
Vector3D p = model.transform(nsp);
Assert.assertEquals(4201866.69291890, p.getX(), 1.0e-6);
Assert.assertEquals(177908.184625686, p.getY(), 1.0e-6);
Assert.assertEquals(4779203.64408617, p.getZ(), 1.0e-6);
}
@Test
public void testOnSurface() throws OrekitException {
Vector3D surfacePoint =
new Vector3D(-1092200.775949484, -3944945.7282234835, 4874931.946956173);
OneAxisEllipsoid earthShape =
new OneAxisEllipsoid(
6378136.460, 1 / 298.257222101, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
GeodeticPoint gp =
earthShape.transform(surfacePoint, earthShape.getBodyFrame(), AbsoluteDate.J2000_EPOCH);
Vector3D rebuilt = earthShape.transform(gp);
Assert.assertEquals(0, rebuilt.distance(surfacePoint), 3.0e-9);
}
@Test
public void testEquatorialInside() throws OrekitException {
AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
Frame frame = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
OneAxisEllipsoid model = new OneAxisEllipsoid(90.0, 5.0 / 9.0, frame);
for (double rho = 0; rho < model.getEquatorialRadius(); rho += 0.01) {
Vector3D point = new Vector3D(rho, 0.0, 0.0);
GeodeticPoint gp = model.transform(point, frame, date);
Vector3D rebuilt = model.transform(gp);
Assert.assertEquals(0.0, rebuilt.distance(point), 1.0e-10);
}
}
@Test
public void testPropagationTypesHyperbolic() throws OrekitException, ParseException, IOException {
SpacecraftState state =
new SpacecraftState(
new KeplerianOrbit(
-10000000.0,
2.5,
0.3,
0,
0,
0.0,
PositionAngle.TRUE,
FramesFactory.getEME2000(),
initDate,
mu));
ForceModel gravityField =
new HolmesFeatherstoneAttractionModel(
FramesFactory.getITRF(IERSConventions.IERS_2010, true),
GravityFieldFactory.getNormalizedProvider(5, 5));
propagator.addForceModel(gravityField);
// Propagation of the initial at t + dt
final PVCoordinates pv = state.getPVCoordinates();
final double dP = 0.001;
final double dV =
state.getMu() * dP / (pv.getPosition().getNormSq() * pv.getVelocity().getNorm());
final PVCoordinates pvcM = propagateInType(state, dP, OrbitType.CARTESIAN, PositionAngle.MEAN);
final PVCoordinates pvkM = propagateInType(state, dP, OrbitType.KEPLERIAN, PositionAngle.MEAN);
final PVCoordinates pvcE =
propagateInType(state, dP, OrbitType.CARTESIAN, PositionAngle.ECCENTRIC);
final PVCoordinates pvkE =
propagateInType(state, dP, OrbitType.KEPLERIAN, PositionAngle.ECCENTRIC);
final PVCoordinates pvcT = propagateInType(state, dP, OrbitType.CARTESIAN, PositionAngle.TRUE);
final PVCoordinates pvkT = propagateInType(state, dP, OrbitType.KEPLERIAN, PositionAngle.TRUE);
Assert.assertEquals(0, pvcM.getPosition().subtract(pvkT.getPosition()).getNorm() / dP, 0.3);
Assert.assertEquals(0, pvcM.getVelocity().subtract(pvkT.getVelocity()).getNorm() / dV, 0.4);
Assert.assertEquals(0, pvkM.getPosition().subtract(pvkT.getPosition()).getNorm() / dP, 0.2);
Assert.assertEquals(0, pvkM.getVelocity().subtract(pvkT.getVelocity()).getNorm() / dV, 0.3);
Assert.assertEquals(0, pvcE.getPosition().subtract(pvkT.getPosition()).getNorm() / dP, 0.3);
Assert.assertEquals(0, pvcE.getVelocity().subtract(pvkT.getVelocity()).getNorm() / dV, 0.4);
Assert.assertEquals(0, pvkE.getPosition().subtract(pvkT.getPosition()).getNorm() / dP, 0.009);
Assert.assertEquals(0, pvkE.getVelocity().subtract(pvkT.getVelocity()).getNorm() / dV, 0.006);
Assert.assertEquals(0, pvcT.getPosition().subtract(pvkT.getPosition()).getNorm() / dP, 0.3);
Assert.assertEquals(0, pvcT.getVelocity().subtract(pvkT.getVelocity()).getNorm() / dV, 0.4);
}
@Test
public void testLineIntersection() throws OrekitException {
AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
Frame frame = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
OneAxisEllipsoid model = new OneAxisEllipsoid(100.0, 0.9, frame);
Vector3D point = new Vector3D(0.0, 93.7139699, 3.5930796);
Vector3D direction = new Vector3D(0.0, 1.0, 1.0);
Line line = new Line(point, point.add(direction), 1.0e-10);
GeodeticPoint gp = model.getIntersectionPoint(line, point, frame, date);
Assert.assertEquals(gp.getAltitude(), 0.0, 1.0e-12);
Assert.assertTrue(line.contains(model.transform(gp)));
model = new OneAxisEllipsoid(100.0, 0.9, frame);
point = new Vector3D(0.0, -93.7139699, -3.5930796);
direction = new Vector3D(0.0, -1.0, -1.0);
line = new Line(point, point.add(direction), 1.0e-10).revert();
gp = model.getIntersectionPoint(line, point, frame, date);
Assert.assertTrue(line.contains(model.transform(gp)));
model = new OneAxisEllipsoid(100.0, 0.9, frame);
point = new Vector3D(0.0, -93.7139699, 3.5930796);
direction = new Vector3D(0.0, -1.0, 1.0);
line = new Line(point, point.add(direction), 1.0e-10);
gp = model.getIntersectionPoint(line, point, frame, date);
Assert.assertTrue(line.contains(model.transform(gp)));
model = new OneAxisEllipsoid(100.0, 0.9, frame);
point = new Vector3D(-93.7139699, 0.0, 3.5930796);
direction = new Vector3D(-1.0, 0.0, 1.0);
line = new Line(point, point.add(direction), 1.0e-10);
gp = model.getIntersectionPoint(line, point, frame, date);
Assert.assertTrue(line.contains(model.transform(gp)));
Assert.assertFalse(line.contains(new Vector3D(0, 0, 7000000)));
point = new Vector3D(0.0, 0.0, 110);
direction = new Vector3D(0.0, 0.0, 1.0);
line = new Line(point, point.add(direction), 1.0e-10);
gp = model.getIntersectionPoint(line, point, frame, date);
Assert.assertEquals(gp.getLatitude(), FastMath.PI / 2, 1.0e-12);
point = new Vector3D(0.0, 110, 0);
direction = new Vector3D(0.0, 1.0, 0.0);
line = new Line(point, point.add(direction), 1.0e-10);
gp = model.getIntersectionPoint(line, point, frame, date);
Assert.assertEquals(gp.getLatitude(), 0, 1.0e-12);
}
@Test
public void testFrance() throws OrekitException {
final BodyShape earth =
new OneAxisEllipsoid(
Constants.WGS84_EARTH_EQUATORIAL_RADIUS,
Constants.WGS84_EARTH_FLATTENING,
FramesFactory.getITRF(IERSConventions.IERS_2010, true));
GeographicZoneDetector d =
new GeographicZoneDetector(20.0, 1.e-3, earth, buildFrance(), FastMath.toRadians(0.5))
.withHandler(new ContinueOnEvent<GeographicZoneDetector>());
Assert.assertEquals(20.0, d.getMaxCheckInterval(), 1.0e-15);
Assert.assertEquals(1.0e-3, d.getThreshold(), 1.0e-15);
Assert.assertEquals(0.5, FastMath.toDegrees(d.getMargin()), 1.0e-15);
Assert.assertEquals(AbstractDetector.DEFAULT_MAX_ITER, d.getMaxIterationCount());
final TimeScale utc = TimeScalesFactory.getUTC();
final Vector3D position = new Vector3D(-6142438.668, 3492467.56, -25767.257);
final Vector3D velocity = new Vector3D(505.848, 942.781, 7435.922);
final AbsoluteDate date = new AbsoluteDate(2003, 9, 16, utc);
final Orbit orbit =
new EquinoctialOrbit(
new PVCoordinates(position, velocity),
FramesFactory.getEME2000(),
date,
Constants.EIGEN5C_EARTH_MU);
Propagator propagator =
new EcksteinHechlerPropagator(
orbit,
Constants.EIGEN5C_EARTH_EQUATORIAL_RADIUS,
Constants.EIGEN5C_EARTH_MU,
Constants.EIGEN5C_EARTH_C20,
Constants.EIGEN5C_EARTH_C30,
Constants.EIGEN5C_EARTH_C40,
Constants.EIGEN5C_EARTH_C50,
Constants.EIGEN5C_EARTH_C60);
EventsLogger logger = new EventsLogger();
propagator.addEventDetector(logger.monitorDetector(d));
propagator.propagate(date.shiftedBy(10 * Constants.JULIAN_DAY));
Assert.assertEquals(26, logger.getLoggedEvents().size());
}
@Test
public void testSerialization()
throws IOException, ClassNotFoundException, NoSuchFieldException, IllegalAccessException,
OrekitException {
final double r = Constants.WGS84_EARTH_EQUATORIAL_RADIUS;
final BodyShape earth =
new OneAxisEllipsoid(
r,
Constants.WGS84_EARTH_FLATTENING,
FramesFactory.getITRF(IERSConventions.IERS_2010, true));
GeographicZoneDetector d =
new GeographicZoneDetector(20.0, 1.e-3, earth, buildFrance(), FastMath.toRadians(0.5))
.withMargin(FastMath.toRadians(0.75))
.withHandler(new ContinueOnEvent<GeographicZoneDetector>());
Assert.assertEquals(r, ((OneAxisEllipsoid) d.getBody()).getEquatorialRadius(), 1.0e-12);
Assert.assertEquals(0.75, FastMath.toDegrees(d.getMargin()), 1.0e-12);
Assert.assertEquals(5.6807e11, d.getZone().getSize() * r * r, 1.0e9);
Assert.assertEquals(4.0289e6, d.getZone().getBoundarySize() * r, 1.0e3);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.writeObject(d);
Assert.assertTrue(bos.size() > 2100);
Assert.assertTrue(bos.size() < 2200);
ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
ObjectInputStream ois = new ObjectInputStream(bis);
GeographicZoneDetector deserialized = (GeographicZoneDetector) ois.readObject();
Assert.assertEquals(d.getZone().getSize(), deserialized.getZone().getSize(), 1.0e-3);
Assert.assertEquals(
d.getZone().getBoundarySize(), deserialized.getZone().getBoundarySize(), 1.0e-3);
Assert.assertEquals(d.getZone().getTolerance(), deserialized.getZone().getTolerance(), 1.0e-15);
Assert.assertEquals(d.getMaxCheckInterval(), deserialized.getMaxCheckInterval(), 1.0e-15);
Assert.assertEquals(d.getThreshold(), deserialized.getThreshold(), 1.0e-15);
Assert.assertEquals(d.getMaxIterationCount(), deserialized.getMaxIterationCount());
Assert.assertTrue(
new RegionFactory<Sphere2D>().difference(d.getZone(), deserialized.getZone()).isEmpty());
}
private void checkCartesianToEllipsoidic(
double ae,
double f,
double x,
double y,
double z,
double longitude,
double latitude,
double altitude)
throws OrekitException {
AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
Frame frame = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
OneAxisEllipsoid model = new OneAxisEllipsoid(ae, f, frame);
GeodeticPoint gp = model.transform(new Vector3D(x, y, z), frame, date);
Assert.assertEquals(longitude, MathUtils.normalizeAngle(gp.getLongitude(), longitude), 1.0e-10);
Assert.assertEquals(latitude, gp.getLatitude(), 1.0e-10);
Assert.assertEquals(altitude, gp.getAltitude(), 1.0e-10 * FastMath.abs(ae));
Vector3D rebuiltNadir = Vector3D.crossProduct(gp.getSouth(), gp.getWest());
Assert.assertEquals(0, rebuiltNadir.subtract(gp.getNadir()).getNorm(), 1.0e-15);
}
@Test
public void testGroundProjectionDerivatives() throws OrekitException {
Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
Frame eme2000 = FramesFactory.getEME2000();
OneAxisEllipsoid model =
new OneAxisEllipsoid(
Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, itrf);
TimeStampedPVCoordinates initPV =
new TimeStampedPVCoordinates(
AbsoluteDate.J2000_EPOCH.shiftedBy(584.),
new Vector3D(3220103., 69623., 6449822.),
new Vector3D(6414.7, -2006., -3180.),
Vector3D.ZERO);
Orbit orbit = new EquinoctialOrbit(initPV, eme2000, Constants.EIGEN5C_EARTH_MU);
double[] errors = derivativesErrors(orbit, orbit.getDate(), eme2000, model);
Assert.assertEquals(0, errors[0], 1.0e-16);
Assert.assertEquals(0, errors[1], 1.0e-12);
Assert.assertEquals(0, errors[2], 2.0e-4);
}
@Before
public void setUp() throws OrekitException {
Utils.setDataRoot("regular-data");
earth =
new OneAxisEllipsoid(
Constants.WGS84_EARTH_EQUATORIAL_RADIUS,
Constants.WGS84_EARTH_FLATTENING,
FramesFactory.getITRF(IERSConventions.IERS_2010, true));
gp = new GeodeticPoint(FastMath.toRadians(51.0), FastMath.toRadians(66.6), 300.0);
final TimeScale utc = TimeScalesFactory.getUTC();
final Vector3D position = new Vector3D(-6142438.668, 3492467.56, -25767.257);
final Vector3D velocity = new Vector3D(505.848, 942.781, 7435.922);
final AbsoluteDate date = new AbsoluteDate(2003, 9, 16, utc);
orbit =
new EquinoctialOrbit(
new PVCoordinates(position, velocity),
FramesFactory.getEME2000(),
date,
Constants.EIGEN5C_EARTH_MU);
}
@Test
public void testGroundProjectionTaylor() throws OrekitException {
Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
Frame eme2000 = FramesFactory.getEME2000();
OneAxisEllipsoid model =
new OneAxisEllipsoid(
Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, itrf);
TimeStampedPVCoordinates initPV =
new TimeStampedPVCoordinates(
AbsoluteDate.J2000_EPOCH.shiftedBy(584.),
new Vector3D(3220103., 69623., 6449822.),
new Vector3D(6414.7, -2006., -3180.),
Vector3D.ZERO);
Orbit orbit = new EquinoctialOrbit(initPV, eme2000, Constants.EIGEN5C_EARTH_MU);
TimeStampedPVCoordinates pv0 = orbit.getPVCoordinates(orbit.getDate(), model.getBodyFrame());
PVCoordinatesProvider groundTaylor =
model.projectToGround(pv0, model.getBodyFrame()).toTaylorProvider(model.getBodyFrame());
TimeStampedPVCoordinates g0 =
groundTaylor.getPVCoordinates(orbit.getDate(), model.getBodyFrame());
Vector3D zenith = pv0.getPosition().subtract(g0.getPosition()).normalize();
Vector3D acrossTrack = Vector3D.crossProduct(zenith, g0.getVelocity()).normalize();
Vector3D alongTrack = Vector3D.crossProduct(acrossTrack, zenith).normalize();
for (double dt = -1; dt < 1; dt += 0.01) {
AbsoluteDate date = orbit.getDate().shiftedBy(dt);
Vector3D taylorP = groundTaylor.getPVCoordinates(date, model.getBodyFrame()).getPosition();
Vector3D refP =
model.projectToGround(
orbit.getPVCoordinates(date, model.getBodyFrame()).getPosition(),
date,
model.getBodyFrame());
Vector3D delta = taylorP.subtract(refP);
Assert.assertEquals(0.0, Vector3D.dotProduct(delta, alongTrack), 0.0015);
Assert.assertEquals(0.0, Vector3D.dotProduct(delta, acrossTrack), 0.0007);
Assert.assertEquals(0.0, Vector3D.dotProduct(delta, zenith), 0.00002);
}
}
@Before
public void setUp() {
try {
Utils.setDataRoot("regular-data");
// Computation date
date =
new AbsoluteDate(
new DateComponents(2008, 04, 07), TimeComponents.H00, TimeScalesFactory.getUTC());
// Body mu
mu = 3.9860047e14;
// Reference frame = ITRF
frameItrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
// Elliptic earth shape
earthSpheric = new OneAxisEllipsoid(6378136.460, 0., frameItrf);
} catch (OrekitException oe) {
Assert.fail(oe.getMessage());
}
}
@Test
public void testGroundProjectionPosition() throws OrekitException {
OneAxisEllipsoid model =
new OneAxisEllipsoid(
Constants.WGS84_EARTH_EQUATORIAL_RADIUS,
Constants.WGS84_EARTH_FLATTENING,
FramesFactory.getITRF(IERSConventions.IERS_2010, true));
TimeStampedPVCoordinates initPV =
new TimeStampedPVCoordinates(
AbsoluteDate.J2000_EPOCH.shiftedBy(584.),
new Vector3D(3220103., 69623., 6449822.),
new Vector3D(6414.7, -2006., -3180.),
Vector3D.ZERO);
Frame eme2000 = FramesFactory.getEME2000();
Orbit orbit = new EquinoctialOrbit(initPV, eme2000, Constants.EIGEN5C_EARTH_MU);
for (double dt = 0; dt < 3600.0; dt += 60.0) {
TimeStampedPVCoordinates pv = orbit.getPVCoordinates(orbit.getDate().shiftedBy(dt), eme2000);
TimeStampedPVCoordinates groundPV = model.projectToGround(pv, eme2000);
Vector3D groundP = model.projectToGround(pv.getPosition(), pv.getDate(), eme2000);
// check methods projectToGround and transform are consistent with each other
Assert.assertEquals(
model.transform(pv.getPosition(), eme2000, pv.getDate()).getLatitude(),
model.transform(groundPV.getPosition(), eme2000, pv.getDate()).getLatitude(),
1.0e-10);
Assert.assertEquals(
model.transform(pv.getPosition(), eme2000, pv.getDate()).getLongitude(),
model.transform(groundPV.getPosition(), eme2000, pv.getDate()).getLongitude(),
1.0e-10);
Assert.assertEquals(
0.0, Vector3D.distance(groundP, groundPV.getPosition()), 1.0e-15 * groundP.getNorm());
}
}
@Test
public void testPropagationTypesElliptical() throws OrekitException, ParseException, IOException {
ForceModel gravityField =
new HolmesFeatherstoneAttractionModel(
FramesFactory.getITRF(IERSConventions.IERS_2010, true),
GravityFieldFactory.getNormalizedProvider(5, 5));
propagator.addForceModel(gravityField);
// Propagation of the initial at t + dt
final PVCoordinates pv = initialState.getPVCoordinates();
final double dP = 0.001;
final double dV =
initialState.getMu() * dP / (pv.getPosition().getNormSq() * pv.getVelocity().getNorm());
final PVCoordinates pvcM =
propagateInType(initialState, dP, OrbitType.CARTESIAN, PositionAngle.MEAN);
final PVCoordinates pviM =
propagateInType(initialState, dP, OrbitType.CIRCULAR, PositionAngle.MEAN);
final PVCoordinates pveM =
propagateInType(initialState, dP, OrbitType.EQUINOCTIAL, PositionAngle.MEAN);
final PVCoordinates pvkM =
propagateInType(initialState, dP, OrbitType.KEPLERIAN, PositionAngle.MEAN);
final PVCoordinates pvcE =
propagateInType(initialState, dP, OrbitType.CARTESIAN, PositionAngle.ECCENTRIC);
final PVCoordinates pviE =
propagateInType(initialState, dP, OrbitType.CIRCULAR, PositionAngle.ECCENTRIC);
final PVCoordinates pveE =
propagateInType(initialState, dP, OrbitType.EQUINOCTIAL, PositionAngle.ECCENTRIC);
final PVCoordinates pvkE =
propagateInType(initialState, dP, OrbitType.KEPLERIAN, PositionAngle.ECCENTRIC);
final PVCoordinates pvcT =
propagateInType(initialState, dP, OrbitType.CARTESIAN, PositionAngle.TRUE);
final PVCoordinates pviT =
propagateInType(initialState, dP, OrbitType.CIRCULAR, PositionAngle.TRUE);
final PVCoordinates pveT =
propagateInType(initialState, dP, OrbitType.EQUINOCTIAL, PositionAngle.TRUE);
final PVCoordinates pvkT =
propagateInType(initialState, dP, OrbitType.KEPLERIAN, PositionAngle.TRUE);
Assert.assertEquals(0, pvcM.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 3.0);
Assert.assertEquals(0, pvcM.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 2.0);
Assert.assertEquals(0, pviM.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.6);
Assert.assertEquals(0, pviM.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.4);
Assert.assertEquals(0, pvkM.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.5);
Assert.assertEquals(0, pvkM.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.3);
Assert.assertEquals(0, pveM.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.2);
Assert.assertEquals(0, pveM.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.2);
Assert.assertEquals(0, pvcE.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 3.0);
Assert.assertEquals(0, pvcE.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 2.0);
Assert.assertEquals(0, pviE.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.03);
Assert.assertEquals(0, pviE.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.04);
Assert.assertEquals(0, pvkE.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.4);
Assert.assertEquals(0, pvkE.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.3);
Assert.assertEquals(0, pveE.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.2);
Assert.assertEquals(0, pveE.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.07);
Assert.assertEquals(0, pvcT.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 3.0);
Assert.assertEquals(0, pvcT.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 2.0);
Assert.assertEquals(0, pviT.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.3);
Assert.assertEquals(0, pviT.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.2);
Assert.assertEquals(0, pvkT.getPosition().subtract(pveT.getPosition()).getNorm() / dP, 0.4);
Assert.assertEquals(0, pvkT.getVelocity().subtract(pveT.getVelocity()).getNorm() / dV, 0.2);
}
@Test
public void testPropagationTypesElliptical() throws OrekitException, ParseException, IOException {
NormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getNormalizedProvider(5, 5);
ForceModel gravityField =
new HolmesFeatherstoneAttractionModel(
FramesFactory.getITRF(IERSConventions.IERS_2010, true), provider);
Orbit initialOrbit =
new KeplerianOrbit(
8000000.0,
0.01,
0.1,
0.7,
0,
1.2,
PositionAngle.TRUE,
FramesFactory.getEME2000(),
AbsoluteDate.J2000_EPOCH,
provider.getMu());
double dt = 900;
double dP = 0.001;
for (OrbitType orbitType : OrbitType.values()) {
for (PositionAngle angleType : PositionAngle.values()) {
// compute state Jacobian using PartialDerivatives
NumericalPropagator propagator =
setUpPropagator(initialOrbit, dP, orbitType, angleType, gravityField);
PartialDerivativesEquations partials =
new PartialDerivativesEquations("partials", propagator);
final SpacecraftState initialState =
partials.setInitialJacobians(new SpacecraftState(initialOrbit), 6, 0);
propagator.setInitialState(initialState);
final JacobiansMapper mapper = partials.getMapper();
PickUpHandler pickUp = new PickUpHandler(mapper, null);
propagator.setMasterMode(pickUp);
propagator.propagate(initialState.getDate().shiftedBy(dt));
double[][] dYdY0 = pickUp.getdYdY0();
// compute reference state Jacobian using finite differences
double[][] dYdY0Ref = new double[6][6];
AbstractIntegratedPropagator propagator2 =
setUpPropagator(initialOrbit, dP, orbitType, angleType, gravityField);
double[] steps = NumericalPropagator.tolerances(1000000 * dP, initialOrbit, orbitType)[0];
for (int i = 0; i < 6; ++i) {
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, -4 * steps[i], i));
SpacecraftState sM4h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, -3 * steps[i], i));
SpacecraftState sM3h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, -2 * steps[i], i));
SpacecraftState sM2h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, -1 * steps[i], i));
SpacecraftState sM1h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, 1 * steps[i], i));
SpacecraftState sP1h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, 2 * steps[i], i));
SpacecraftState sP2h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, 3 * steps[i], i));
SpacecraftState sP3h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
propagator2.resetInitialState(
shiftState(initialState, orbitType, angleType, 4 * steps[i], i));
SpacecraftState sP4h = propagator2.propagate(initialState.getDate().shiftedBy(dt));
fillJacobianColumn(
dYdY0Ref, i, orbitType, angleType, steps[i], sM4h, sM3h, sM2h, sM1h, sP1h, sP2h, sP3h,
sP4h);
}
for (int i = 0; i < 6; ++i) {
for (int j = 0; j < 6; ++j) {
double error = FastMath.abs((dYdY0[i][j] - dYdY0Ref[i][j]) / dYdY0Ref[i][j]);
Assert.assertEquals(0, error, 6.0e-2);
}
}
}
}
}
@Test
public void testWithOriginalTestsCases() throws OrekitException, ParseException {
Frame itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
PVCoordinatesProvider sun = CelestialBodyFactory.getSun();
OneAxisEllipsoid earth = new OneAxisEllipsoid(6378136.460, 1.0 / 298.257222101, itrf);
SolarInputs97to05 in = SolarInputs97to05.getInstance();
earth.setAngularThreshold(1e-10);
DTM2000 atm = new DTM2000(in, sun, earth);
double roTestCase;
double tzTestCase;
double tinfTestCase;
double myRo;
// Inputs :
// alt=800.
// lat=40.
// day=185.
// hl=16.
// xlon=0.
// fm(1)=150.
// f(1) =fm(1)
// fm(2)=0.
// f(2)=0.
// akp(1)=0.
// akp(2)=0.
// akp(3)=0.
// akp(4)=0.
// Outputs :
roTestCase = 1.8710001353820e-17 * 1000;
tzTestCase = 1165.4839828984;
tinfTestCase = 1165.4919505608;
// Computation and results
myRo =
atm.getDensity(
185, 800 * 1000, 0, FastMath.toRadians(40), 16 * FastMath.PI / 12, 150, 150, 0, 0);
Assert.assertEquals(0, (roTestCase - myRo) / roTestCase, 1e-14);
Assert.assertEquals(0, (tzTestCase - atm.getT()) / tzTestCase, 1e-13);
Assert.assertEquals(0, (tinfTestCase - atm.getTinf()) / tinfTestCase, 1e-13);
// IDEM., day=275
roTestCase = 2.8524195214905e-17 * 1000;
tzTestCase = 1157.1872001392;
tinfTestCase = 1157.1933514185;
myRo =
atm.getDensity(
275, 800 * 1000, 0, FastMath.toRadians(40), 16 * FastMath.PI / 12, 150, 150, 0, 0);
Assert.assertEquals(0, (roTestCase - myRo) / roTestCase, 1e-14);
Assert.assertEquals(0, (tzTestCase - atm.getT()) / tzTestCase, 1e-13);
Assert.assertEquals(0, (tinfTestCase - atm.getTinf()) / tinfTestCase, 1e-13);
// IDEM., day=355
roTestCase = 1.7343324462212e-17 * 1000;
tzTestCase = 1033.0277846356;
tinfTestCase = 1033.0282703200;
myRo =
atm.getDensity(
355, 800 * 1000, 0, FastMath.toRadians(40), 16 * FastMath.PI / 12, 150, 150, 0, 0);
Assert.assertEquals(0, (roTestCase - myRo) / roTestCase, 2e-14);
Assert.assertEquals(0, (tzTestCase - atm.getT()) / tzTestCase, 1e-13);
Assert.assertEquals(0, (tinfTestCase - atm.getTinf()) / tinfTestCase, 1e-13);
// IDEM., day=85
roTestCase = 2.9983740796297e-17 * 1000;
tzTestCase = 1169.5405086196;
tinfTestCase = 1169.5485768345;
myRo =
atm.getDensity(
85, 800 * 1000, 0, FastMath.toRadians(40), 16 * FastMath.PI / 12, 150, 150, 0, 0);
Assert.assertEquals(0, (roTestCase - myRo) / roTestCase, 1e-14);
Assert.assertEquals(0, (tzTestCase - atm.getT()) / tzTestCase, 1e-13);
Assert.assertEquals(0, (tinfTestCase - atm.getTinf()) / tinfTestCase, 1e-13);
// alt=500.
// lat=-70. NB: the subroutine requires latitude in rad
// day=15.
// hl=16. NB: the subroutine requires local time in rad (0hr=0 rad)
// xlon=0.
// fm(1)=70.
// f(1) =fm(1)
// fm(2)=0.
// f(2)=0.
// akp(1)=0.
// akp(2)=0.
// akp(3)=0.
// akp(4)=0.
// ro= 1.3150282384722D-16
// tz= 793.65487014559
// tinf= 793.65549802348
// roTestCase = 1.3150282384722E-16;
// tzTestCase= 793.65487014559;
// tinfTestCase= 793.65549802348;
atm.getDensity(15, 500 * 1000, 0, FastMath.toRadians(-70), 16 * FastMath.PI / 12, 70, 70, 0, 0);
// IDEM., alt=800.
// ro= 1.9556768571305D-18
// tz= 793.65549797919
// tinf= 793.65549802348
atm.getDensity(15, 800 * 1000, 0, FastMath.toRadians(-70), 16 * FastMath.PI / 12, 70, 70, 0, 0);
}
@Test
public void testIntersectionFromPoints() throws OrekitException {
AbsoluteDate date =
new AbsoluteDate(
new DateComponents(2008, 03, 21), TimeComponents.H12, TimeScalesFactory.getUTC());
Frame frame = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
OneAxisEllipsoid earth = new OneAxisEllipsoid(6378136.460, 1 / 298.257222101, frame);
// Satellite on polar position
// ***************************
final double mu = 3.9860047e14;
CircularOrbit circ =
new CircularOrbit(
7178000.0,
0.5e-4,
0.,
FastMath.toRadians(90.),
FastMath.toRadians(60.),
FastMath.toRadians(90.),
PositionAngle.MEAN,
FramesFactory.getEME2000(),
date,
mu);
// Transform satellite position to position/velocity parameters in EME2000 and ITRF200B
PVCoordinates pvSatEME2000 = circ.getPVCoordinates();
PVCoordinates pvSatItrf =
frame.getTransformTo(FramesFactory.getEME2000(), date).transformPVCoordinates(pvSatEME2000);
Vector3D pSatItrf = pvSatItrf.getPosition();
// Test first visible surface points
GeodeticPoint geoPoint =
new GeodeticPoint(FastMath.toRadians(70.), FastMath.toRadians(60.), 0.);
Vector3D pointItrf = earth.transform(geoPoint);
Line line = new Line(pSatItrf, pointItrf, 1.0e-10);
GeodeticPoint geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(geoPoint.getLongitude(), geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(geoPoint.getLatitude(), geoInter.getLatitude(), Utils.epsilonAngle);
// Test second visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(65.), FastMath.toRadians(-120.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(geoPoint.getLongitude(), geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(geoPoint.getLatitude(), geoInter.getLatitude(), Utils.epsilonAngle);
// Test non visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(30.), FastMath.toRadians(60.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
// For polar satellite position, intersection point is at the same longitude but different
// latitude
Assert.assertEquals(1.04437199, geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(1.36198012, geoInter.getLatitude(), Utils.epsilonAngle);
// Satellite on equatorial position
// ********************************
circ =
new CircularOrbit(
7178000.0,
0.5e-4,
0.,
FastMath.toRadians(1.e-4),
FastMath.toRadians(0.),
FastMath.toRadians(0.),
PositionAngle.MEAN,
FramesFactory.getEME2000(),
date,
mu);
// Transform satellite position to position/velocity parameters in EME2000 and ITRF200B
pvSatEME2000 = circ.getPVCoordinates();
pvSatItrf =
frame.getTransformTo(FramesFactory.getEME2000(), date).transformPVCoordinates(pvSatEME2000);
pSatItrf = pvSatItrf.getPosition();
// Test first visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(5.), FastMath.toRadians(0.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
Assert.assertTrue(line.toSubSpace(pSatItrf).getX() < 0);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(geoPoint.getLongitude(), geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(geoPoint.getLatitude(), geoInter.getLatitude(), Utils.epsilonAngle);
// With the point opposite to satellite point along the line
GeodeticPoint geoInter2 =
earth.getIntersectionPoint(
line, line.toSpace(new Vector1D(-line.toSubSpace(pSatItrf).getX())), frame, date);
Assert.assertTrue(
FastMath.abs(geoInter.getLongitude() - geoInter2.getLongitude()) > FastMath.toRadians(0.1));
Assert.assertTrue(
FastMath.abs(geoInter.getLatitude() - geoInter2.getLatitude()) > FastMath.toRadians(0.1));
// Test second visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(-5.), FastMath.toRadians(0.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(geoPoint.getLongitude(), geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(geoPoint.getLatitude(), geoInter.getLatitude(), Utils.epsilonAngle);
// Test non visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(40.), FastMath.toRadians(0.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(-0.00768481, geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(0.32180410, geoInter.getLatitude(), Utils.epsilonAngle);
// Satellite on any position
// *************************
circ =
new CircularOrbit(
7178000.0,
0.5e-4,
0.,
FastMath.toRadians(50.),
FastMath.toRadians(0.),
FastMath.toRadians(90.),
PositionAngle.MEAN,
FramesFactory.getEME2000(),
date,
mu);
// Transform satellite position to position/velocity parameters in EME2000 and ITRF200B
pvSatEME2000 = circ.getPVCoordinates();
pvSatItrf =
frame.getTransformTo(FramesFactory.getEME2000(), date).transformPVCoordinates(pvSatEME2000);
pSatItrf = pvSatItrf.getPosition();
// Test first visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(40.), FastMath.toRadians(90.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(geoPoint.getLongitude(), geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(geoPoint.getLatitude(), geoInter.getLatitude(), Utils.epsilonAngle);
// Test second visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(60.), FastMath.toRadians(90.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(geoPoint.getLongitude(), geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(geoPoint.getLatitude(), geoInter.getLatitude(), Utils.epsilonAngle);
// Test non visible surface points
geoPoint = new GeodeticPoint(FastMath.toRadians(0.), FastMath.toRadians(90.), 0.);
pointItrf = earth.transform(geoPoint);
line = new Line(pSatItrf, pointItrf, 1.0e-10);
geoInter = earth.getIntersectionPoint(line, pSatItrf, frame, date);
Assert.assertEquals(
FastMath.toRadians(89.5364061088196), geoInter.getLongitude(), Utils.epsilonAngle);
Assert.assertEquals(
FastMath.toRadians(35.555543683351125), geoInter.getLatitude(), Utils.epsilonAngle);
}
