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# aticq

erfa.aticq(ri, di, astrom)

  Quick CIRS RA,Dec to ICRS astrometric place, given the star- independent astrometry parameters.

  Parameters:
    ri double array
    di double array
    astrom eraASTROM array
  Returns:
    rc double array
    dc double array

  Notes

  Wraps ERFA function `eraAticq`. The ERFA documentation is:

      - - - - - - - - -
       e r a A t i c q
      - - - - - - - - -

      Quick CIRS RA,Dec to ICRS astrometric place, given the star-
      independent astrometry parameters.

      Use of this function is appropriate when efficiency is important and
      where many star positions are all to be transformed for one date.
      The star-independent astrometry parameters can be obtained by
      calling one of the functions eraApci[13], eraApcg[13], eraApco[13]
      or eraApcs[13].

      Given:
         ri,di  double     CIRS RA,Dec (radians)
         astrom eraASTROM* star-independent astrometry parameters:
          pmt    double       PM time interval (SSB, Julian years)
          eb     double[3]    SSB to observer (vector, au)
          eh     double[3]    Sun to observer (unit vector)
          em     double       distance from Sun to observer (au)
          v      double[3]    barycentric observer velocity (vector, c)
          bm1    double       sqrt(1-|v|^2): reciprocal of Lorenz factor
          bpn    double[3][3] bias-precession-nutation matrix
          along  double       longitude + s' (radians)
          xpl    double       polar motion xp wrt local meridian (radians)
          ypl    double       polar motion yp wrt local meridian (radians)
          sphi   double       sine of geodetic latitude
          cphi   double       cosine of geodetic latitude
          diurab double       magnitude of diurnal aberration vector
          eral   double       "local" Earth rotation angle (radians)
          refa   double       refraction constant A (radians)
          refb   double       refraction constant B (radians)

      Returned:
         rc,dc  double     ICRS astrometric RA,Dec (radians)

      Notes:

      1) Only the Sun is taken into account in the light deflection
         correction.

      2) Iterative techniques are used for the aberration and light
         deflection corrections so that the functions eraAtic13 (or
         eraAticq) and eraAtci13 (or eraAtciq) are accurate inverses;
         even at the edge of the Sun's disk the discrepancy is only about
         1 nanoarcsecond.

      Called:
         eraS2c       spherical coordinates to unit vector
         eraTrxp      product of transpose of r-matrix and p-vector
         eraZp        zero p-vector
         eraAb        stellar aberration
         eraLdsun     light deflection by the Sun
         eraC2s       p-vector to spherical
         eraAnp       normalize angle into range +/- pi

      This revision:   2013 October 9

      Copyright (C) 2013-2023, NumFOCUS Foundation.
      Derived, with permission, from the SOFA library.  See notes at end of file.