; DECSHIFT
;---------------------------------------------------------------
;! gives Y-coordinate shift of an image center from reference
;# ADVERB IMAGING
;-----------------------------------------------------------------------
;;  Copyright (C) 1995-1996, 1999, 2020
;;  Associated Universities, Inc. Washington DC, USA.
;;
;;  This program is free software; you can redistribute it and/or
;;  modify it under the terms of the GNU General Public License as
;;  published by the Free Software Foundation; either version 2 of
;;  the License, or (at your option) any later version.
;;
;;  This program is distributed in the hope that it will be useful,
;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;  GNU General Public License for more details.
;;
;;  You should have received a copy of the GNU General Public
;;  License along with this program; if not, write to the Free
;;  Software Foundation, Inc., 675 Massachusetts Ave, Cambridge,
;;  MA 02139, USA.
;;
;;  Correspondence concerning AIPS should be addressed as follows:
;;         Internet email: aipsmail@nrao.edu.
;;         Postal address: AIPS Project Office
;;                         National Radio Astronomy Observatory
;;                         520 Edgemont Road
;;                         Charlottesville, VA 22903-2475 USA
;-----------------------------------------------------------------------
DECSHIFT  LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
----------------------------------------------------------------
DECSHIFT
Type:  Adverb (Real array, 64 elements)
Use:   Specifies a change or shift of the declination (or Y) coordinate
       of an image, one per FIELD.  Specifies a shift Northward (larger
       Y-pixel value) of the map center.
       The actual new center Declination is given by
              Dec(i) = Dec_0 + DECSHIFT(i)
       where Dec_0 is the declination of the reference point.

       If more than 64 fields are needed use BOXFILE to specify the
       shifts or field centers.  DECSHIFT is used only if BOXFILE is
       not.

Null Value:  NONE  ( 0 => no shift)
Tasks:
   BOXES.......Adds Clean boxes to BOXFILE around sources from a list.
   CHKFC.......Makes images of Clean boxes from Boxfile.
   FIXBX.......Converts a BOXFILE to another for input to IMAGR.
   IMAGR.......Wide-field and/or wide-frequency Cleaning / imaging
               task.
   SCIMG.......Full-featured imaging plus self-calibration loop with
               editing.
   UVCON....   Generate sample UV coverage given a user defined array
               layout.
Procedures:
   CXPOLN......Procedure to make complex polarization images and beam.
   LINIMAGE....Build image cube from multi-IF data set.
----------------------------------------------------------------
