@property
def radial_velocity(self):
    '\n        Radial velocity of target relative to the observer.\n\n        Returns\n        -------\n        `~astropy.units.Quantity`\n            Radial velocity of target.\n\n        Notes\n        -----\n        This is different from the ``.radial_velocity`` property of a\n        coordinate frame in that this calculates the radial velocity with\n        respect to the *observer*, not the origin of the frame.\n        '
    if ((self._observer is None) or (self._target is None)):
        if (self._radial_velocity is None):
            return (0 * KMS)
        else:
            return self._radial_velocity
    else:
        return self._calculate_radial_velocity(self._observer, self._target, as_scalar=True)
Radial velocity of target relative to the observer.

Returns
-------
`~astropy.units.Quantity`
    Radial velocity of target.

Notes
-----
This is different from the ``.radial_velocity`` property of a
coordinate frame in that this calculates the radial velocity with
respect to the *observer*, not the origin of the frame.
@property
def radial_velocity(self):
    '\n        Radial velocity of target relative to the observer.\n\n        Returns\n        -------\n        `~astropy.units.Quantity`\n            Radial velocity of target.\n\n        Notes\n        -----\n        This is different from the ``.radial_velocity`` property of a\n        coordinate frame in that this calculates the radial velocity with\n        respect to the *observer*, not the origin of the frame.\n        '
    if ((self._observer is None) or (self._target is None)):
        if (self._radial_velocity is None):
            return (0 * KMS)
        else:
            return self._radial_velocity
    else:
        return self._calculate_radial_velocity(self._observer, self._target, as_scalar=True)