[rc, dc] = ERFA.aticq(ri, di, astrom)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, eraApcg, eraApco or eraApcs.
ri,di double CIRS RA,Dec (radians)
astrom ASTROM* 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)
rc,dc double ICRS astrometric RA,Dec (radians)
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Only the Sun is taken into account in the light deflection correction.
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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.
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) 2013-2021, NumFOCUS Foundation. Derived, with permission, from the SOFA library.