Program:       SKYTRANS

Purpose:       Transformation between equatorial, galactic, ecliptic and
               supergalactic coordinates.

Category:      COORDINATES, UTILITY

File:          skytrans.c

Author:        M.G.R. Vogelaar

Keywords:


   FILENAME=   Write output to file with name:   [skip writing]
               Write output to a file on disk. Output coordinates
               are written in degrees in two column format.
               You are not allowed to write to a file that already
               exists.               

   SKYSYSIN=   Give sky system of input *, G, E or S:  [*(=Equatorial)]
               * == equatorial system.
               G == Galactic system.
               E == Ecliptic system.
               S == Supergalactic system.

   EPOCHIN=    Give epoch of input:                            [1950.0]
               Precession correction for the year EPOCHIN= is applied
               for the Equatorial and Ecliptic system.

   SKYSYSOUT=  Give sky system of output *, G, E or S:       [Galactic]

   EPOCHOUT=   Give epoch of output:                           [1950.0]
               See remark at EPOCHIN=

   COORD=      Position RA,DEC as d d  or hms dms:               [stop]
               or:
               Position l,b as d d or dms dms:                   [stop]
              
               Positions can be given as coordinate pairs in
               degrees or in hms/dms notation (6 numbers needed).
               If you enter a negative declination in dms notation,
               only the first field needs the minus sign.

   QUIT=       Quit?                                             [Y]/N
               Quit program or enter new sky systems.


Description:   SKYTRANS is an coordinate transformation utility that
               performs transformations between equatorial, galactic,
               ecliptic and supergalactic coordinates. Input coordinate
               system is defined by SKYSYSIN= Known sky systems are:

               * == equatorial system.
               G == Galactic system.
               E == Ecliptic system.
               S == Supergalactic system.

               If the equatorial system is selected, an epoch is needed
               also. This number is in years after 0.0. The same
               remarks can be made for the output sky system.
               Positions can be given entered as:

               COORD=123.4 34.0        | Two numbers in degrees (all systems)
               COORD=4 23 23.3 5 34 0  | hms 4h23m23.3s dms 5d34m0s
                                         (equatorial)
               COORD=4 23 23.3 5 34 0  | dms 4d23m23.3s dms 5d34m0s
                                         (not equatorial)
               COORD=4 23 23.3 -5 34 0 | hms 4d23m23.3s dms -5d34m0s

Notes:

Example:       <USER> SKYTRANS
               SKYTRANS  Version 1.0  (Nov  4 1992)
               <USER> SKYTRANS SKYSYSIN=
               <USER> SKYTRANS EPOCHIN=
               <USER> SKYTRANS SKYSYSOUT=S

                      RA DEC (1950.0)       ==>    Super gal. l b
               ===============================================================
               <USER> SKYTRANS COORD=2 10 0 45 0 0
                2h10m 0.00s , 45d 0m  0.0s  ==>  344d50m 35.0s , - 2d 0m 19.3s
               ( 32.500000,  45.000000 deg. ==> 344.843068,  -2.005373 deg.)
               <USER> SKYTRANS COORD=
               <USER> SKYTRANS QUIT=
               <STATUS>  SKYTRANS   +++ FINISHED +++


Updates:       Nov 3,  1992: VOG, Document created.
               Sep 15, 1995: VOG, FILENAME= added.