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authorJoseph Hunkeler <jhunkeler@gmail.com>2015-07-08 20:46:52 -0400
committerJoseph Hunkeler <jhunkeler@gmail.com>2015-07-08 20:46:52 -0400
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treebdda434976bc09c864f2e4fa6f16ba1952b1e555 /math/slalib/map.f
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+ 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