NAME: mkastinfo PURPOSE: (one line only) Generate a simple astrometric description of an image DESCRIPTION: CATEGORY: Astrometry 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.