pygaia/errors/astrometric.py
def positionErrorSkyAvg(G, vmini, extension=0.0):
  """
  Calculate the sky averaged position errors from G and (V-I).

  NOTE! THE ERRORS ARE FOR SKY POSITIONS 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 error in alpha* and the error in delta, in that order, in micro-arcsecond.
  """
  parallaxError = parallaxErrorSkyAvg(G, vmini, extension=extension)
  return _scalingForPositions['AlphaStar']*parallaxError, \
         _scalingForPositions['Delta']*parallaxError
def positionErrorSkyAvg(G, vmini, extension=0.0):
  """
  Calculate the sky averaged position errors from G and (V-I).

  NOTE! THE ERRORS ARE FOR SKY POSITIONS 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 error in alpha* and the error in delta, in that order, in micro-arcsecond.
  """
  parallaxError = parallaxErrorSkyAvg(G, vmini, extension=extension)
  return _scalingForPositions['AlphaStar']*parallaxError, \
         _scalingForPositions['Delta']*parallaxError
Calculate the sky averaged position errors from G and (V-I).

  NOTE! THE ERRORS ARE FOR SKY POSITIONS 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 error in alpha* and the error in delta, in that order, in micro-arcsecond.