@Test
public void testMiss() throws OrekitException {
final CircularOrbit circ =
new CircularOrbit(
7178000.0,
0.5e-4,
-0.5e-4,
FastMath.toRadians(0.),
FastMath.toRadians(270.),
FastMath.toRadians(5.300),
PositionAngle.MEAN,
FramesFactory.getEME2000(),
date,
mu);
final LofOffset upsideDown =
new LofOffset(circ.getFrame(), LOFType.VVLH, RotationOrder.XYX, FastMath.PI, 0, 0);
final LofOffsetPointing pointing =
new LofOffsetPointing(earthSpheric, upsideDown, Vector3D.PLUS_K);
try {
pointing.getTargetPV(circ, date, circ.getFrame());
Assert.fail("an exception should have been thrown");
} catch (OrekitException oe) {
Assert.assertEquals(
OrekitMessages.ATTITUDE_POINTING_LAW_DOES_NOT_POINT_TO_GROUND, oe.getSpecifier());
}
}
private double[] stateToArray(
SpacecraftState state, OrbitType orbitType, PositionAngle angleType, boolean withMass) {
double[] array = new double[withMass ? 7 : 6];
switch (orbitType) {
case CARTESIAN:
{
CartesianOrbit cart = (CartesianOrbit) orbitType.convertType(state.getOrbit());
array[0] = cart.getPVCoordinates().getPosition().getX();
array[1] = cart.getPVCoordinates().getPosition().getY();
array[2] = cart.getPVCoordinates().getPosition().getZ();
array[3] = cart.getPVCoordinates().getVelocity().getX();
array[4] = cart.getPVCoordinates().getVelocity().getY();
array[5] = cart.getPVCoordinates().getVelocity().getZ();
}
break;
case CIRCULAR:
{
CircularOrbit circ = (CircularOrbit) orbitType.convertType(state.getOrbit());
array[0] = circ.getA();
array[1] = circ.getCircularEx();
array[2] = circ.getCircularEy();
array[3] = circ.getI();
array[4] = circ.getRightAscensionOfAscendingNode();
array[5] = circ.getAlpha(angleType);
}
break;
case EQUINOCTIAL:
{
EquinoctialOrbit equ = (EquinoctialOrbit) orbitType.convertType(state.getOrbit());
array[0] = equ.getA();
array[1] = equ.getEquinoctialEx();
array[2] = equ.getEquinoctialEy();
array[3] = equ.getHx();
array[4] = equ.getHy();
array[5] = equ.getL(angleType);
}
break;
case KEPLERIAN:
{
KeplerianOrbit kep = (KeplerianOrbit) orbitType.convertType(state.getOrbit());
array[0] = kep.getA();
array[1] = kep.getE();
array[2] = kep.getI();
array[3] = kep.getPerigeeArgument();
array[4] = kep.getRightAscensionOfAscendingNode();
array[5] = kep.getAnomaly(angleType);
}
break;
}
if (withMass) {
array[6] = state.getMass();
}
return array;
}
/** Test if both constructors are equivalent */
@Test
public void testLof() throws OrekitException {
// Satellite position
final CircularOrbit circ =
new CircularOrbit(
7178000.0,
0.5e-4,
-0.5e-4,
FastMath.toRadians(0.),
FastMath.toRadians(270.),
FastMath.toRadians(5.300),
PositionAngle.MEAN,
FramesFactory.getEME2000(),
date,
mu);
// Create lof aligned law
// ************************
final LofOffset lofLaw = new LofOffset(circ.getFrame(), LOFType.VVLH);
final LofOffsetPointing lofPointing =
new LofOffsetPointing(earthSpheric, lofLaw, Vector3D.PLUS_K);
final Rotation lofRot = lofPointing.getAttitude(circ, date, circ.getFrame()).getRotation();
// Compare to body center pointing law
// *************************************
final BodyCenterPointing centerLaw = new BodyCenterPointing(earthSpheric.getBodyFrame());
final Rotation centerRot = centerLaw.getAttitude(circ, date, circ.getFrame()).getRotation();
final double angleBodyCenter = centerRot.applyInverseTo(lofRot).getAngle();
Assert.assertEquals(0., angleBodyCenter, Utils.epsilonAngle);
// Compare to nadir pointing law
// *******************************
final NadirPointing nadirLaw = new NadirPointing(earthSpheric);
final Rotation nadirRot = nadirLaw.getAttitude(circ, date, circ.getFrame()).getRotation();
final double angleNadir = nadirRot.applyInverseTo(lofRot).getAngle();
Assert.assertEquals(0., angleNadir, Utils.epsilonAngle);
}
@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);
}
