MKASTINFO

Name

mkastinfo

Purpose (one Line Only)

Generate a simple astrometric description of an image

Description

Calling Sequence

mkastinfo,racen,deccen,xcen,ycen,scale,info

Inputs

racen - Right ascension of the center of the array, also assumed to
be the tangent plane point for the xi,eta to ra,dec
transformation. Can be provided in radians or as a
sexigesimal string.
deccen - Declination of the array center. Same input options as racen.
xcen - X coordinate of the array center
ycen - Y coordinate of the array center
scale - Scale of the image in arcsec/pixel

Optional Input Parameters

XFLIP - flag, if set reverses the x axis
YFLIP - flag, if set reverses the y axis
POSANG - Rotation angle between x,y and xi,eta, in degrees, gives
the position angle of the y axis on the sky measured
east of north.
Note: the posang rotation is applied BEFORE either axis is flipped.
Then, the flip is applied to the rotated system.
RENORMFAC - Renormalization factor for the x,y coordinates. The default
is 1.0 and rarely needs to be otherwise for the synthetic
astrometric solution generated by this routine.

Keyword Input Parameters

Outputs

info - This is an anonymous structure compatible with the astrometry
routines (eg., astsn2xy, astsn2rd, and so on). This structure
defines a full, strictly linear coordinate transformation
intended for describing synthetic or linearized images.

Keyword Output Parameters

Common Blocks

Side Effects

Restrictions

This routine is not intended for fitting images so it does not attempt
to provide access and control of the full power of the transformation.
Only linear descriptions are generated and the tangent point is always
intended to be in the center of the array.

Procedure

Modification History

Written by Marc W. Buie, Southwest Research Institute, 2009/11/15
2009/12/02, MWB, changed to consolidate xiterms and etaterms into one.