aticq¶
- erfa.aticq(ri, di, astrom)[source]¶
Quick CIRS RA,Dec to ICRS astrometric place, given the star- independent astrometry parameters.
- Parameters:
- ridouble array
- didouble array
- astromeraASTROM array
- Returns:
- rcdouble array
- dcdouble 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.