def test_from_coord_fails_if_no_time_differential(): pos = [30000, 0, 0] * u.km cartrep = CartesianRepresentation(*pos) # Method fails if coordinate instance doesn't contain a differential with # respect to time with pytest.raises(ValueError) as excinfo: Orbit.from_coords(Earth, SkyCoord(cartrep)) assert ( "ValueError: Coordinate instance doesn't have a differential with respect to time" in excinfo.exconly())
def test_from_coord_fails_if_no_time_differential(): pos = [30000, 0, 0] * u.km cartrep = CartesianRepresentation(*pos) # Method fails if coordinate instance doesn't contain a differential with # respect to time with pytest.raises(ValueError) as excinfo: Orbit.from_coords(Earth, SkyCoord(cartrep)) assert ( "ValueError: Coordinate instance doesn't have a differential with respect to time" in excinfo.exconly() )
def test_from_coord_fails_for_multiple_positions(obstime): cartdiff = CartesianDifferential([[0, 1, 0], [-0.1, 0.9, 0]] * u.km / u.s, xyz_axis=1) cartrep = CartesianRepresentation([[1, 0, 0], [0.9, 0.1, 0]] * u.km, differentials=cartdiff, xyz_axis=1) coords = GCRS(cartrep, representation_type=CartesianRepresentation, obstime=obstime) with pytest.raises(ValueError) as excinfo: Orbit.from_coords(Earth, coords) assert ( "ValueError: Coordinate instance must represents exactly 1 position, found: 2" in excinfo.exconly())
def test_from_coord_fails_for_multiple_positions(obstime): cartdiff = CartesianDifferential( [[0, 1, 0], [-0.1, 0.9, 0]] * u.km / u.s, xyz_axis=1 ) cartrep = CartesianRepresentation( [[1, 0, 0], [0.9, 0.1, 0]] * u.km, differentials=cartdiff, xyz_axis=1 ) coords = GCRS(cartrep, representation_type=CartesianRepresentation, obstime=obstime) with pytest.raises(ValueError) as excinfo: Orbit.from_coords(Earth, coords) assert ( "ValueError: Coordinate instance must represents exactly 1 position, found: 2" in excinfo.exconly() )
def test_orbit_creation_using_frame_obj(attractor, frame, obstime): vel = [0, 2, 0] * u.km / u.s cartdiff = CartesianDifferential(*vel) pos = [30000, 0, 0] * u.km cartrep = CartesianRepresentation(*pos, differentials=cartdiff) coord = frame(cartrep, obstime=obstime) o = Orbit.from_coords(attractor, coord) inertial_frame_at_body_centre = get_frame(attractor, Planes.EARTH_EQUATOR, obstime=coord.obstime) coord_transformed_to_irf = coord.transform_to( inertial_frame_at_body_centre) pos_transformed_to_irf = coord_transformed_to_irf.cartesian.xyz vel_transformed_to_irf = coord_transformed_to_irf.cartesian.differentials[ "s"].d_xyz assert_quantity_allclose(o.r, pos_transformed_to_irf, atol=1e-5 * u.km) assert_quantity_allclose(o.v, vel_transformed_to_irf, atol=1e-5 * u.km / u.s)
def findstrike(velocity, alt, az): ''' Parameters ---------- velocity : A `float` alt: A `float` az: A `float` Returns ------- A `tuple` of two floats ''' p = sphericalToCartesian(velocity, alt, az) vx = p[0] vy = p[1] vz = p[2] g = GCRS(x=0 * u.km, y=0 * u.km, z=(Earth.R.to(u.km).value + 8.848) * u.km, v_x=vx * u.km / u.s, v_y=vy * u.km / u.s, v_z=vz * u.km / u.s, representation_type=CartesianRepresentation, differential_type=CartesianDifferential) orb = Orbit.from_coords(Earth, g) tof = timeOfFlight(orb.ecc.value) orb2 = orb.propagate(tof) position = orb.r.value m = CartesianToSpherical(position[0], position[1], position[2]) alt = m[1] * u.rad az = m[2] * u.rad altd = alt.to(u.deg) azd = az.to(u.deg) return altd, azd
def test_from_coord_if_coord_is_not_of_shape_zero(): pos = [0, 1, 0] vel = [1, 0, 0] cartdiff = CartesianDifferential([vel] * u.km / u.s, xyz_axis=1) cartrep = CartesianRepresentation([pos] * u.km, differentials=cartdiff, xyz_axis=1) coords = GCRS(cartrep, representation_type=CartesianRepresentation, obstime=J2000) ss = Orbit.from_coords(Earth, coords) assert_quantity_allclose(ss.r, pos * u.km, rtol=1e-5) assert_quantity_allclose(ss.v, vel * u.km / u.s, rtol=1e-5)
def test_orbit_creation_using_skycoord(attractor): vel = [0, 2, 0] * u.km / u.s cartdiff = CartesianDifferential(*vel) pos = [30_000, 0, 0] * u.km cartrep = CartesianRepresentation(*pos, differentials=cartdiff) coord = SkyCoord(cartrep, frame="icrs") o = Orbit.from_coords(attractor, coord) inertial_frame_at_body_centre = get_frame( attractor, Planes.EARTH_EQUATOR, obstime=coord.obstime ) coord_transformed_to_irf = coord.transform_to(inertial_frame_at_body_centre) pos_transformed_to_irf = coord_transformed_to_irf.cartesian.xyz vel_transformed_to_irf = coord_transformed_to_irf.cartesian.differentials["s"].d_xyz assert (o.r == pos_transformed_to_irf).all() assert (o.v == vel_transformed_to_irf).all()
def test_orbit_creation_using_skycoord(attractor): vel = [0, 2, 0] * u.km / u.s cartdiff = CartesianDifferential(*vel) pos = [30000, 0, 0] * u.km cartrep = CartesianRepresentation(*pos, differentials=cartdiff) coord = SkyCoord(cartrep, frame="icrs") o = Orbit.from_coords(attractor, coord) inertial_frame_at_body_centre = get_frame( attractor, Planes.EARTH_EQUATOR, obstime=coord.obstime ) coord_transformed_to_irf = coord.transform_to(inertial_frame_at_body_centre) pos_transformed_to_irf = coord_transformed_to_irf.cartesian.xyz vel_transformed_to_irf = coord_transformed_to_irf.cartesian.differentials["s"].d_xyz assert (o.r == pos_transformed_to_irf).all() assert (o.v == vel_transformed_to_irf).all()
def test_orbit_creation_using_frame_obj(attractor, frame, obstime): vel = [0, 2, 0] * u.km / u.s cartdiff = CartesianDifferential(*vel) pos = [30000, 0, 0] * u.km cartrep = CartesianRepresentation(*pos, differentials=cartdiff) coord = frame(cartrep, obstime=obstime) o = Orbit.from_coords(attractor, coord) inertial_frame_at_body_centre = get_frame( attractor, Planes.EARTH_EQUATOR, obstime=coord.obstime ) coord_transformed_to_irf = coord.transform_to(inertial_frame_at_body_centre) pos_transformed_to_irf = coord_transformed_to_irf.cartesian.xyz vel_transformed_to_irf = coord_transformed_to_irf.cartesian.differentials["s"].d_xyz assert_quantity_allclose(o.r, pos_transformed_to_irf, atol=1e-5 * u.km) assert_quantity_allclose(o.v, vel_transformed_to_irf, atol=1e-5 * u.km / u.s)