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author | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-03-04 21:21:30 -0500 |
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committer | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-03-04 21:21:30 -0500 |
commit | d54fe7c1f704a63824c5bfa0ece65245572e9b27 (patch) | |
tree | afc52015ffc2c74e0266653eecef1c8ef8ba5d91 /src/slalib/map.f | |
download | calfuse-d54fe7c1f704a63824c5bfa0ece65245572e9b27.tar.gz |
Initial commit
Diffstat (limited to 'src/slalib/map.f')
-rw-r--r-- | src/slalib/map.f | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/src/slalib/map.f b/src/slalib/map.f new file mode 100644 index 0000000..6046774 --- /dev/null +++ b/src/slalib/map.f @@ -0,0 +1,75 @@ + SUBROUTINE sla_MAP (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: +* sla_MAPPA star-independent parameters +* sla_MAPQK 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 sla_PM 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 sla_MAPPA routine +* once and then either the sla_MAPQK routine (which includes +* parallax and proper motion) or sla_MAPQKZ (which assumes +* zero parallax and proper motion). +* +* P.T.Wallace Starlink 19 January 1993 +* +* Copyright (C) 1995 Rutherford Appleton Laboratory +*- + + IMPLICIT NONE + + DOUBLE PRECISION RM,DM,PR,PD,PX,RV,EQ,DATE,RA,DA + + DOUBLE PRECISION AMPRMS(21) + + + +* Star-independent parameters + CALL sla_MAPPA(EQ,DATE,AMPRMS) + +* Mean to apparent + CALL sla_MAPQK(RM,DM,PR,PD,PX,RV,AMPRMS,RA,DA) + + END |