observed_from_icrs

rubin_sim.utils.observed_from_icrs(ra, dec, pm_ra=None, pm_dec=None, parallax=None, v_rad=None, obs_metadata=None, epoch=None, include_refraction=True)

Convert mean position (RA, Dec) in the International Celestial Reference Frame to observed (RA, Dec).

included are precession-nutation, aberration, proper motion, parallax, refraction, radial velocity, diurnal aberration.

This method works in degrees.

@param [in] ra is the unrefracted RA in degrees (ICRS). Can be a numpy array or a number.

@param [in] dec is the unrefracted Dec in degrees (ICRS). Can be a numpy array or a number.

@param [in] pm_ra is proper motion in RA multiplied by cos(Dec) (arcsec/yr) Can be a numpy array or a number or None (default=None).

@param [in] pm_dec is proper motion in dec (arcsec/yr) Can be a numpy array or a number or None (default=None).

@param [in] parallax is parallax in arcsec Can be a numpy array or a number or None (default=None).

@param [in] v_rad is radial velocity (km/s) Can be a numpy array or a number or None (default=None).

@param [in] obs_metadata is an ObservationMetaData object describing the telescope pointing.

@param [in] epoch is the julian epoch (in years) against which the mean equinoxes are measured.

@param [in] include_refraction toggles whether or not to correct for refraction

@param [out] a 2-D numpy array in which the first row is the observed RA and the second row is the observed Dec (both in degrees)