Subroutine: IRCO_NEWCOOR
Purpose: introduce a new coordinate system
Category WORLD COORDINATES, IRAS
File: irco.shl
Author: Do Kester
Person resp.: Do Kester
Address: guspace!do or rugfx4!do (uucp)
Use: call irco_newcoor(
refcoor I integer
pole_angle I doubleprecision
ref_asc_node I doubleprecision
new_asc_node I doubleprecision
newname I character*(*)
newcoor I/O integer )
refcoor reference coordinate system; see below.
pole_angle angle between the poles of the systems
ref_asc_node longitude of asc.node in reference system
new_asc_node longitude of asc.node in new system
newname to be assigned to the new system
newcoor input: 0 => output: free coordinate number
otherwise output = input
Description:
A new coordinate system will be created, defined with
respect to REFCOOR. Three angles are necessary to
define the new system: the distance between the north poles,
and the longitude of the ascending node in both the reference
and the new system. The angles are given in radians.
No epoch will be assigned to the new system which means
that the system can not be precessed.
If NEWCOOR equals REFCOOR or another existing coordinate number,
all existing transformation matrices that referred to that
coordinate number will be overwritten. If NEWCOOR
is 0 upon entry, a free coordinate number will be returned,
or 0 if none is available any more.
Upon output NEWCOOR contains the number of the new system.
The connection to coordinate system nr 1 is always made, so that
all connections with other systems will be present in one or
two steps.
Externals:
Updates: 5 jan 1990 DK, documentation only
17 DEC 1990 DK, make always connection with system nr 1