AIPS HELP file for MAPSHIFT in 31DEC25

As of Wed Mar 26 15:46:10 2025

HELP SECTION

MAPSHIFT
Type: Adverb  (Array(2))
Use:  The shift of the image center from the phase center of the uv
      data file.
      Adverb is only known after RUN MAPPR.

      RA,DEC shift of the phase center of image from the tangent point
      of the uv data in asec.  Map center = tangent point + shift.
      If X>0 shifts map center to east.  NOTE:
         MAPSHIFT(1) is a shift in RA scaled by cos (Dec_0) as
            Ra_new(i) = RA_0 + MAPSHIFT(1) / cos (Dec_0)
         where _0 => the tangent point in the uv data.
         Declination shift of map center from tangent point:
            Dec_new = Dec_0 + MAPSHIFT(2).  If MAPSHIFT(2)>0
         shifts map center to north.

Procedures:
   MAPPR.........Simplified access to IMAGR.

EXPLAIN SECTION