'Interpolate polar motions from IERS Table for given dates.
Parameters
jd1 : float, float array, or Time object
first part of two-part JD, or Time object
jd2 : float or float array, optional
second part of two-part JD.
Default is 0., ignored if jd1 is `~astropy.time.Time`.
return_status : bool
Whether to return status values.  If False (default),
raise ``IERSRangeError`` if any time is out of the range covered
by the IERS table.
Returns
PM_x : Quantity with angle units
x component of polar motion for the requested times
PM_y : Quantity with angle units
y component of polar motion for the requested times
status : int or int array
Status values (if ``return_status``=``True``)::
``iers.FROM_IERS_B``
``iers.FROM_IERS_A``
``iers.FROM_IERS_A_PREDICTION``
``iers.TIME_BEFORE_IERS_RANGE``
``iers.TIME_BEYOND_IERS_RANGE``'

def pm_xy(self, jd1, jd2=0.0, return_status=False):

    return self._interpolate(jd1, jd2, [u'PM_x', u'PM_y'], (self.pm_source if return_status else None))
