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author | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-07-08 20:46:52 -0400 |
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committer | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-07-08 20:46:52 -0400 |
commit | fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 (patch) | |
tree | bdda434976bc09c864f2e4fa6f16ba1952b1e555 /math/slalib/map.f | |
download | iraf-linux-fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4.tar.gz |
Initial commit
Diffstat (limited to 'math/slalib/map.f')
-rw-r--r-- | math/slalib/map.f | 99 |
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diff --git a/math/slalib/map.f b/math/slalib/map.f new file mode 100644 index 00000000..5c019fcd --- /dev/null +++ b/math/slalib/map.f @@ -0,0 +1,99 @@ + SUBROUTINE slMAP (RM, DM, PR, PD, PX, RV, EQ, DATE, RA, DA) +*+ +* - - - - +* M A P +* - - - - +* +* Transform star RA,Dec from mean place to geocentric apparent +* +* The reference frames and timescales used are post IAU 1976. +* +* References: +* 1984 Astronomical Almanac, pp B39-B41. +* (also Lederle & Schwan, Astron. Astrophys. 134, +* 1-6, 1984) +* +* Given: +* RM,DM dp mean RA,Dec (rad) +* PR,PD dp proper motions: RA,Dec changes per Julian year +* PX dp parallax (arcsec) +* RV dp radial velocity (km/sec, +ve if receding) +* EQ dp epoch and equinox of star data (Julian) +* DATE dp TDB for apparent place (JD-2400000.5) +* +* Returned: +* RA,DA dp apparent RA,Dec (rad) +* +* Called: +* slMAPA star-independent parameters +* slMAPQ quick mean to apparent +* +* Notes: +* +* 1) EQ is the Julian epoch specifying both the reference frame and +* the epoch of the position - usually 2000. For positions where +* the epoch and equinox are different, use the routine slPM to +* apply proper motion corrections before using this routine. +* +* 2) The distinction between the required TDB and TT is always +* negligible. Moreover, for all but the most critical +* applications UTC is adequate. +* +* 3) The proper motions in RA are dRA/dt rather than cos(Dec)*dRA/dt. +* +* 4) This routine may be wasteful for some applications because it +* recomputes the Earth position/velocity and the precession- +* nutation matrix each time, and because it allows for parallax +* and proper motion. Where multiple transformations are to be +* carried out for one epoch, a faster method is to call the +* slMAPA routine once and then either the slMAPQ routine +* (which includes parallax and proper motion) or slMAPZ (which +* assumes zero parallax and proper motion). +* +* 5) The accuracy is sub-milliarcsecond, limited by the +* precession-nutation model (IAU 1976 precession, Shirai & +* Fukushima 2001 forced nutation and precession corrections). +* +* 6) The accuracy is further limited by the routine slEVP, called +* by slMAPA, which computes the Earth position and velocity +* using the methods of Stumpff. The maximum error is about +* 0.3 mas. +* +* P.T.Wallace Starlink 17 September 2001 +* +* Copyright (C) 2001 Rutherford Appleton Laboratory +* +* License: +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation; either version 2 of the License, or +* (at your option) any later version. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with this program (see SLA_CONDITIONS); if not, write to the +* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, +* Boston, MA 02110-1301 USA +* +* Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. +*- + + IMPLICIT NONE + + DOUBLE PRECISION RM,DM,PR,PD,PX,RV,EQ,DATE,RA,DA + + DOUBLE PRECISION AMPRMS(21) + + + +* Star-independent parameters + CALL slMAPA(EQ,DATE,AMPRMS) + +* Mean to apparent + CALL slMAPQ(RM,DM,PR,PD,PX,RV,AMPRMS,RA,DA) + + END |