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authorJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
committerJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
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+.help map Jun99 "Slalib Package"
+.nf
+
+ 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).
+
+ P.T.Wallace Starlink 19 January 1993
+
+ Copyright (C) 1995 Rutherford Appleton Laboratory
+ Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
+
+.fi
+.endhelp