def test_obsgeo_cartesian(dkist_location):
obstime = Time("2021-05-21T03:00:00")
wcs = WCS(naxis=2)
wcs.wcs.obsgeo = list(dkist_location.to_value(u.m).tolist()) + [0, 0, 0]
wcs.wcs.dateobs = obstime.isot
frame = obsgeo_to_frame(wcs.wcs.obsgeo, obstime)
assert isinstance(frame, ITRS)
assert frame.x == dkist_location.x
assert frame.y == dkist_location.y
assert frame.z == dkist_location.z
def test_obsgeo_spherical(dkist_location):
obstime = Time("2021-05-21T03:00:00")
dkist_location = dkist_location.get_itrs(obstime)
loc_sph = dkist_location.spherical
wcs = WCS(naxis=2)
wcs.wcs.obsgeo = [0, 0, 0] + [
loc_sph.lon.value, loc_sph.lat.value, loc_sph.distance.value
]
wcs.wcs.dateobs = obstime.isot
frame = obsgeo_to_frame(wcs.wcs.obsgeo, obstime)
assert isinstance(frame, ITRS)
assert u.allclose(frame.x, dkist_location.x)
assert u.allclose(frame.y, dkist_location.y)
assert u.allclose(frame.z, dkist_location.z)
def test_obsgeo_invalid(obsgeo):
with pytest.raises(ValueError):
obsgeo_to_frame(obsgeo, None)
def solar_wcs_frame_mapping(wcs):
"""
This function registers the coordinates frames to their FITS-WCS coordinate
type values in the `astropy.wcs.utils.wcs_to_celestial_frame` registry.
Parameters
----------
wcs : astropy.wcs.WCS
Returns
-------
astropy.coordinates.BaseCoordinateFrame
"""
if hasattr(wcs, "coordinate_frame"):
return wcs.coordinate_frame
dateobs = wcs.wcs.dateobs or None
# Get observer coordinate from the WCS auxillary information
required_attrs = {
HeliographicStonyhurst: ['hgln_obs', 'hglt_obs', 'dsun_obs'],
HeliographicCarrington: ['crln_obs', 'hglt_obs', 'dsun_obs']
}
# Get rsun from the WCS auxillary information
rsun = wcs.wcs.aux.rsun_ref
if rsun is not None:
rsun *= u.m
# TODO: remove these errors in sunpy 4.1
bad_attrs = [
f'.{attr}' for attr in ['rsun', 'heliographic_observer']
if hasattr(wcs, attr)
]
if len(bad_attrs):
raise ValueError(
f"The {' and '.join(bad_attrs)} attribute(s) on a WCS "
"are no longer supported.")
observer = None
for frame, attr_names in required_attrs.items():
attrs = [getattr(wcs.wcs.aux, attr_name) for attr_name in attr_names]
if all([attr is not None for attr in attrs]):
kwargs = {'obstime': dateobs}
if rsun is not None:
kwargs['rsun'] = rsun
if issubclass(frame, HeliographicCarrington):
kwargs['observer'] = 'self'
observer = frame(attrs[0] * u.deg, attrs[1] * u.deg,
attrs[2] * u.m, **kwargs)
# Read the observer out of obsgeo for ground based observers
if observer is None:
try:
observer = obsgeo_to_frame(wcs.wcs.obsgeo, dateobs)
observer = SkyCoord(observer, rsun=rsun)
except ValueError as e:
# The helper function assumes you know the obsgeo coords you are
# parsing are good, we are not sure, so catch the error.
# This approach could lead to an invalid observer (i.e. one of the
# coords being NaN), but only if the WCS has been constructed like that.
log.debug(f"Could not parse obsgeo coordinates from WCS:\n{e}")
# Collect all of the possible frame attributes, although some may be removed later
frame_args = {'obstime': dateobs}
if observer is not None:
frame_args['observer'] = observer
if rsun is not None:
frame_args['rsun'] = rsun
frame_class = _sunpy_frame_class_from_ctypes(wcs.wcs.ctype)
if frame_class:
if frame_class == HeliographicStonyhurst:
frame_args.pop('observer', None)
if frame_class == Heliocentric:
frame_args.pop('rsun', None)
return frame_class(**frame_args)
def solar_wcs_frame_mapping(wcs):
"""
This function registers the coordinates frames to their FITS-WCS coordinate
type values in the `astropy.wcs.utils.wcs_to_celestial_frame` registry.
Parameters
----------
wcs : astropy.wcs.WCS
Returns
-------
astropy.coordinates.BaseCoordinateFrame
"""
if hasattr(wcs, "coordinate_frame"):
return wcs.coordinate_frame
dateobs = wcs.wcs.dateobs or None
# Get observer coordinate from the WCS auxillary information
required_attrs = {
HeliographicStonyhurst: ['hgln_obs', 'hglt_obs', 'dsun_obs'],
HeliographicCarrington: ['crln_obs', 'hglt_obs', 'dsun_obs']
}
# Get rsun from the WCS auxillary information
rsun = wcs.wcs.aux.rsun_ref
if rsun is not None:
rsun *= u.m
# This custom attribute was always used in sunpy < 2.1; these warnings
# can be converted into errors in sunpy 3.1
if hasattr(wcs, 'rsun'):
warnings.warn(
'Support for the .rsun attribute on a WCS is deprecated. '
'Set observer keywords in the FITS header, or directly set the wcs.wcs.aux '
'values instead.', SunpyUserWarning)
if rsun is None:
rsun = wcs.rsun
else:
warnings.warn(
'rsun information present in WCS auxillary information, ignoring '
'.rsun', SunpyUserWarning)
observer = None
for frame, attr_names in required_attrs.items():
attrs = [getattr(wcs.wcs.aux, attr_name) for attr_name in attr_names]
if all([attr is not None for attr in attrs]):
kwargs = {'obstime': dateobs}
if rsun is not None:
kwargs['rsun'] = rsun
if issubclass(frame, HeliographicCarrington):
kwargs['observer'] = 'self'
observer = frame(attrs[0] * u.deg, attrs[1] * u.deg,
attrs[2] * u.m, **kwargs)
# Read the observer out of obsgeo for ground based observers
if observer is None:
try:
observer = obsgeo_to_frame(wcs.wcs.obsgeo, dateobs)
observer = SkyCoord(observer, rsun=rsun)
except ValueError as e:
# The helper function assumes you know the obsgeo coords you are
# parsing are good, we are not sure, so catch the error.
# This approach could lead to an invalid observer (i.e. one of the
# coords being NaN), but only if the WCS has been constructed like that.
log.debug(f"Could not parse obsgeo coordinates from WCS:\n{e}")
# This custom attribute was always used in sunpy < 2.1; these warnings
# can be converted into errors in sunpy 3.1
if hasattr(wcs, 'heliographic_observer'):
warnings.warn(
'Support for the .heliographic_observer attribute on a WCS is deprecated. '
'Set observer keywords in the FITS header, or directly set the wcs.wcs.aux '
'values instead.', SunpyUserWarning)
if observer is None:
observer = wcs.heliographic_observer
else:
warnings.warn(
'Observer information present in WCS auxillary information, ignoring '
'.heliographic_observer', SunpyUserWarning)
# Truncate the ctype to the first four letters
ctypes = {c[:4] for c in wcs.wcs.ctype}
if {'HPLN', 'HPLT'} <= ctypes:
return Helioprojective(obstime=dateobs, observer=observer, rsun=rsun)
if {'HGLN', 'HGLT'} <= ctypes:
return HeliographicStonyhurst(obstime=dateobs)
if {'CRLN', 'CRLT'} <= ctypes:
return HeliographicCarrington(obstime=dateobs, observer=observer)
if {'SOLX', 'SOLY'} <= ctypes:
return Heliocentric(obstime=dateobs, observer=observer)
