Subroutine:     IRDS_ENQUIRE

Purpose:        returns some basic info about an existing IRDS

File:   	irds_basic.c

Author:         Do Kester

Use:    CALL IRDS_ENQUIRE( IRDS,     I     character*(*)
                           OBJECT,   O     character*(*)
                           INSTRU,   O     character*(*)
   	      		   NAXIS,    O	   integer
                           AXES,     O     integer array (naxis)
                           CENTER,   O     double array (2)
                           SIZE,     O     double array (2)
                           COOR,     O     character*(*)
                           EPOCHE,   O     real
                           STATUS )  O     integer

        IRDS    name of (existing) irds to open
	OBJECT	object identification
        INSTRU  instrument identification
	NAXIS	the number of axes of the IRDS
        AXES    length of the axes of the irds (fast to slow)
        CENTER  longitude & latitude of custum plate center
        SIZE    of custom plate in lon & lat direction
        COOR    coordinate system identification
	EPOCHE	the epoche of the coordinate system if applicable
        STATUS   0 : OK. 
                -1 : the irds does not exist
                -2 : not enough axes exist
		-3 : instru is missing
		-4 : center is missing
		-5 : size is missing
		-6 : coor is missing
                -7 : object is missing
                -8 : epoche is missing

Description:    
        irds_enquire tests whether a given irds exists and if so
        it returns information on the instrument, on the length
        of the axes in order fast to slow, on the center and the
        size of the custom plate and on the coordinate system
        these value are given in. 

        Both the instrument and the coordinate system are coded
        strings. (see IRDS_CREATE)

Externals:      gds_exist

Updates:        23/02/90 DK, document creation
		16/10/90 DK, documentation update