### ARD_WCS

Specify WCS information to be used in future calls to ARD_WORK

#### Description:

This routine can be used to specify the coordinate systems which can be used in subsequent calls to ARD_WORK. ARD descriptions passed to subsequent calls to ARD_WORK can include positions in any of the Frames included in the supplied FrameSet. The ARD description should include suitable COFRAME or WCS statements to indicate which coordinate system is being used. If no COFRAME or WCS statements are included in the ARD description, then it is assumed that positions within the ARD description are given in the current Frame of the supplied FrameSet, IWCS.

If this routine is not called prior to ARD_WORK (or if it is called with IWCS set AST__NULL), then the ARD description must provide (either directly or through a WCS statement) positions in pixel coordinates.

The FrameSet pointer supplied is simply stored by this routine. If any changes are subsequently made to the FrameSet by the calling routine, then these changes will be visible within ARD_WORK. In particular, if the calling routine annuls the FrameSet pointer, then ARD_WORK will fail.

The supplied FrameSet will be used by all subsequent calls to ARD_WORK until a new FrameSet is specified by calling ARD_WCS again.

#### Invocation

CALL ARD_WCS( IWCS, DOMAIN, STATUS )

#### Arguments

##### IWCS = INTEGER (Given)
An AST pointer to a FrameSet, or AST__NULL.
##### DOMAIN = CHARACTER $\ast$ ( $\ast$ ) (Given)
The Domain name corresponding to pixel coordinates within the mask array passed to routine ARD_WORK. If a blank value is supplied,  "PIXEL " will be used. The IWCS FrameSet (if supplied) must contain a Frame with this Domain. If the supplied string is longer than 40 characters, the trailing characters are ignored.
##### STATUS = INTEGER (Given and Returned)
The global status.