def test_icrs_body_position_to_planetary_frame_yields_zeros(body, frame):
with solar_system_ephemeris.set("builtin"):
epoch = J2000
vector = get_body_barycentric(body.name, epoch)
vector_result = (ICRS(vector).transform_to(
frame(obstime=epoch)).represent_as(CartesianRepresentation))
assert_quantity_allclose(vector_result.xyz, [0, 0, 0] * u.km,
atol=1e-7 * u.km)
def test_planetary_icrs_frame_is_just_translation(body, frame):
epoch = J2000
vector = CartesianRepresentation(x=100 * u.km, y=100 * u.km, z=100 * u.km)
vector_result = (
frame(vector, obstime=epoch)
.transform_to(ICRS())
.represent_as(CartesianRepresentation)
)
expected_result = get_body_barycentric(body.name, epoch) + vector
assert_quantity_allclose(vector_result.xyz, expected_result.xyz)
def test_orbit_from_ephem_is_in_icrs_frame(body):
ss = Orbit.from_body_ephem(body)
assert ss.get_frame().is_equivalent_frame(ICRS())