def test_spice_earth():
# Replace the ICRS->AltAz transform in astropy with one using SPICE.
# Confirm that star positions are the same as with the original transform
# to within the error due to relativistic aberration (~ 21 arcsec)
stars = ltests.get_catalog()
lat, lon = 30, 25
loc = EarthLocation.from_geodetic(lon, lat)
altaz = stars.transform_to(AltAz(location=loc))
trans_path, steps = frame_transform_graph.find_shortest_path(ICRS, AltAz)
assert steps == 2
# Make the Earth topo frame in spice.
framename, idnum, frame_dict, latlon = lunarsky.spice_utils.topo_frame_def(
lat, lon, moon=False)
# One more kernel is needed for the ITRF93 frame.
kname = 'pck/earth_latest_high_prec.bpc'
_naif_kernel_url = 'https://naif.jpl.nasa.gov/pub/naif/generic_kernels'
kurl = [_naif_kernel_url + '/' + kname]
kernpath = download_files_in_parallel(kurl,
cache=True,
show_progress=False,
pkgname='lunarsky')
spice.furnsh(kernpath)
frame_strs = ["{}={}".format(k, v) for (k, v) in frame_dict.items()]
spice.lmpool(frame_strs)
@frame_transform_graph.transform(FunctionTransformWithFiniteDifference,
ICRS, AltAz)
def icrs_to_mcmf(icrs_coo, mcmf_frame):
mat = spice.pxform('J2000', framename, 0)
newrepr = icrs_coo.cartesian.transform(mat)
return mcmf_frame.realize_frame(newrepr)
trans_path2, steps2 = frame_transform_graph.find_shortest_path(ICRS, AltAz)
assert steps2 == 1
altaz2 = stars.transform_to(AltAz(location=loc))
# Having done the transform, remove the spice transform from the graph
frame_transform_graph.remove_transform(ICRS, AltAz, None)
trans_path2, steps2 = frame_transform_graph.find_shortest_path(ICRS, AltAz)
assert steps2 == 2
assert ltests.positions_close(altaz, altaz2, Angle(25, 'arcsec'))
def test_unit_representation_subclass():
class Longitude180(Longitude):
def __new__(cls, angle, unit=None, wrap_angle=180*u.deg, **kwargs):
self = super(Longitude180, cls).__new__(cls, angle, unit=unit,
wrap_angle=wrap_angle, **kwargs)
return self
class UnitSphericalWrap180Representation(UnitSphericalRepresentation):
attr_classes = OrderedDict([('lon', Longitude180),
('lat', Latitude)])
recommended_units = {'lon': u.deg, 'lat': u.deg}
class SphericalWrap180Representation(SphericalRepresentation):
attr_classes = OrderedDict([('lon', Longitude180),
('lat', Latitude),
('distance', u.Quantity)])
recommended_units = {'lon': u.deg, 'lat': u.deg}
_unit_representation = UnitSphericalWrap180Representation
class myframe(ICRS):
default_representation = SphericalWrap180Representation
frame_specific_representation_info = {
'spherical': [RepresentationMapping('lon', 'ra'),
RepresentationMapping('lat', 'dec')]
}
frame_specific_representation_info['unitspherical'] = \
frame_specific_representation_info['unitsphericalwrap180'] = \
frame_specific_representation_info['sphericalwrap180'] = \
frame_specific_representation_info['spherical']
@frame_transform_graph.transform(FunctionTransform,
myframe, astropy.coordinates.ICRS)
def myframe_to_icrs(myframe_coo, icrs):
return icrs.realize_frame(myframe_coo._data)
f = myframe(10*u.deg, 10*u.deg)
assert isinstance(f._data, UnitSphericalWrap180Representation)
assert isinstance(f.ra, Longitude180)
g = f.transform_to(astropy.coordinates.ICRS)
assert isinstance(g, astropy.coordinates.ICRS)
assert isinstance(g._data, UnitSphericalWrap180Representation)
frame_transform_graph.remove_transform(myframe,
astropy.coordinates.ICRS,
None)
def test_unit_representation_subclass():
class Longitude180(Longitude):
def __new__(cls, angle, unit=None, wrap_angle=180 * u.deg, **kwargs):
self = super(Longitude180, cls).__new__(cls,
angle,
unit=unit,
wrap_angle=wrap_angle,
**kwargs)
return self
class UnitSphericalWrap180Representation(UnitSphericalRepresentation):
attr_classes = OrderedDict([('lon', Longitude180), ('lat', Latitude)])
recommended_units = {'lon': u.deg, 'lat': u.deg}
class SphericalWrap180Representation(SphericalRepresentation):
attr_classes = OrderedDict([('lon', Longitude180), ('lat', Latitude),
('distance', u.Quantity)])
recommended_units = {'lon': u.deg, 'lat': u.deg}
_unit_representation = UnitSphericalWrap180Representation
class myframe(ICRS):
default_representation = SphericalWrap180Representation
frame_specific_representation_info = {
'spherical': [
RepresentationMapping('lon', 'ra'),
RepresentationMapping('lat', 'dec')
]
}
frame_specific_representation_info['unitspherical'] = \
frame_specific_representation_info['unitsphericalwrap180'] = \
frame_specific_representation_info['sphericalwrap180'] = \
frame_specific_representation_info['spherical']
@frame_transform_graph.transform(FunctionTransform, myframe,
astropy.coordinates.ICRS)
def myframe_to_icrs(myframe_coo, icrs):
return icrs.realize_frame(myframe_coo._data)
f = myframe(10 * u.deg, 10 * u.deg)
assert isinstance(f._data, UnitSphericalWrap180Representation)
assert isinstance(f.ra, Longitude180)
g = f.transform_to(astropy.coordinates.ICRS)
assert isinstance(g, astropy.coordinates.ICRS)
assert isinstance(g._data, UnitSphericalWrap180Representation)
frame_transform_graph.remove_transform(myframe, astropy.coordinates.ICRS,
None)