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;;; Line-dependent integration time correction for HRI IR in Mode 5 (ALTFF)
;;;
;;; Keywords:
;;;
;;;   MODE     LONG, HRI IR instrument mode (1-7)
;;;            - if not present, keyword FITSHDR will be used
;;;
;;;   FITSHDR  STRING[], FITS header, for searching for MODE via SXPAR
;;;            - ignored if MODE is used
;;;            - mode keyword is IMGMODE
;;;
;;; Return value:
;;;
;;;   ***N.B. UNITS of return value is ms (milliseconds)
;;;
;;;   IF mode is 5, THEN return an array DOUBLE[512,256] containing
;;;   offsets to be ADDED to the nominal integration time
;;;
;;;   ELSE return scalar zero (DOUBLE 0d0, i.e. no correction)
;;;
;;; Description:
;;;
;;;   HRI IR data pixel taken in Mode 5 (ALTFF) have line-dependent
;;;   integration times which vary by 46ms from the first row to the
;;;   last row, decreasing with increasing row.  This function implements
;;;   that variation as an offset to be added to the nominal integration.
;;;   time, typically keyword INTTIME.
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function dicalir_varinttime, mode=modeArg, fitsHdr=fitsHdr

  mode = n_elements(modeArg) eq 1L ? long(modeArg[0]) : SXPAR(fitsHdr,'IMGMODE')

  return $
  , mode NE 5L $
    ?  0d0 $
    :  ( replicate(-1d0,512) # (46d0 * (dindgen(256)-127.5d0) / 255d0) )

end