def to_geodetic(self, ellipsoid=None):
"""Convert to geodetic coordinates.
Parameters
----------
ellipsoid : str, optional
Reference ellipsoid to use. Default is the one the coordinates
were initialized with. Available are: 'WGS84', 'GRS80', 'WGS72'
Returns
-------
(lon, lat, height) : tuple
The tuple contains instances of `~astropy.coordinates.Longitude`,
`~astropy.coordinates.Latitude`, and `~astropy.units.Quantity`
Raises
------
ValueError
if ``ellipsoid`` is not recognized as among the ones implemented.
Notes
-----
For the conversion to geodetic coordinates, the ERFA routine
``gc2gd`` is used. See https://github.com/liberfa/erfa
"""
ellipsoid = _check_ellipsoid(ellipsoid, default=self.ellipsoid)
self_array = self.to(u.meter).view(self._array_dtype, np.ndarray)
lon, lat, height = erfa.gc2gd(getattr(erfa, ellipsoid), self_array)
return GeodeticLocation(
Longitude(lon * u.radian,
u.degree,
wrap_angle=180. * u.degree,
copy=False),
Latitude(lat * u.radian, u.degree, copy=False),
u.Quantity(height * u.meter, self.unit, copy=False))
def from_cartesian(cls, cart):
"""
Converts 3D rectangular cartesian coordinates (assumed geocentric) to
WGS84 geodetic coordinates.
"""
lon, lat, height = erfa.gc2gd(getattr(erfa, cls._ellipsoid),
cart.get_xyz(xyz_axis=-1))
return cls(lon, lat, height, copy=False)