@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);
}
@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);
}
@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);
}
}
@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(expected = OrekitException.class)
public void testNotInitialised2() throws OrekitException {
final AbstractIntegratedPropagator notInitialised =
new NumericalPropagator(new ClassicalRungeKuttaIntegrator(10.0));
notInitialised.propagate(AbsoluteDate.J2000_EPOCH, AbsoluteDate.J2000_EPOCH.shiftedBy(3600));
}