pygaia/errors/astrometric.py
def properMotionMinError(G, vmini, extension=0.0):
  """
  Calculate the minimum proper motion errors from G and (V-I). These correspond to the sky regions with
  the smallest astrometric errors.

  NOTE! THE ERRORS ARE FOR PROPER MOTIONS IN THE ICRS (I.E., RIGHT ASCENSION, DECLINATION). MAKE SURE
  YOUR SIMULATED ASTROMETRY IS ALSO ON THE ICRS.

  Parameters
  ----------

  G     - Value(s) of G-band magnitude.
  vmini - Value(s) of (V-I) colour.

  Keywords
  --------

  extension - Add this amount of years to the mission lifetime and scale the errors accordingly.

  Returns
  -------

  The minimum error in mu_alpha* and the error in mu_delta, in that order, in micro-arcsecond/year.
  """
  factor = errorScalingMissionLength(extension, -1.5)
  parallaxError = parallaxErrorSkyAvg(G, vmini)*factor
  return _astrometricErrorFactors['muAlphaStar'].min()*parallaxError, \
         _astrometricErrorFactors['muDelta'].min()*parallaxError
def properMotionMinError(G, vmini, extension=0.0):
  """
  Calculate the minimum proper motion errors from G and (V-I). These correspond to the sky regions with
  the smallest astrometric errors.

  NOTE! THE ERRORS ARE FOR PROPER MOTIONS IN THE ICRS (I.E., RIGHT ASCENSION, DECLINATION). MAKE SURE
  YOUR SIMULATED ASTROMETRY IS ALSO ON THE ICRS.

  Parameters
  ----------

  G     - Value(s) of G-band magnitude.
  vmini - Value(s) of (V-I) colour.

  Keywords
  --------

  extension - Add this amount of years to the mission lifetime and scale the errors accordingly.

  Returns
  -------

  The minimum error in mu_alpha* and the error in mu_delta, in that order, in micro-arcsecond/year.
  """
  factor = errorScalingMissionLength(extension, -1.5)
  parallaxError = parallaxErrorSkyAvg(G, vmini)*factor
  return _astrometricErrorFactors['muAlphaStar'].min()*parallaxError, \
         _astrometricErrorFactors['muDelta'].min()*parallaxError
Calculate the minimum proper motion errors from G and (V-I). These correspond to the sky regions with
  the smallest astrometric errors.

  NOTE! THE ERRORS ARE FOR PROPER MOTIONS IN THE ICRS (I.E., RIGHT ASCENSION, DECLINATION). MAKE SURE
  YOUR SIMULATED ASTROMETRY IS ALSO ON THE ICRS.

  Parameters
  ----------

  G     - Value(s) of G-band magnitude.
  vmini - Value(s) of (V-I) colour.

  Keywords
  --------

  extension - Add this amount of years to the mission lifetime and scale the errors accordingly.

  Returns
  -------

  The minimum error in mu_alpha* and the error in mu_delta, in that order, in micro-arcsecond/year.