FUNCTION asca_of_flight, flt_grade
; Compute an ASCA grade array from the flight grade array
; Use ASCA-Flight mapping from Appendix D of TARA User's guide
; which is excerpt from "ACIS Grading Scheme Recomendation"
;

; Form the look up table
  map = INTARR(256) + 7  ; default is 7
  map(0) = 0
  grade1 = [1,4,5,32,33,36,37,128, $
		129,132,133,160,161,164,165]
  map(grade1) = 1
  grade2 = [2,34,64,65,68,69,130,162]
  map(grade2) = 2
  grade3 = [8,12,136,140]
  map(grade3) = 3
  grade4 = [16,17,48,49]
  map(grade4) = 4
  grade5 = [3,6,9,13,20,21,35,38, $
		40,44,52,53,96,97,100, $
		101,131,134,137,141, $
		144,145,163,166, $
		168,172,176,177,192, $
		193,196,197]
  map(grade5) = 5
  grade6 = [10,11,18,22,50,54,72, $
		76,80,81,104,108,138, $
		139,208,209]
  map(grade6) = 6
; Do it
  asca_grade = flt_grade*0 + 7
  ie = LONG(0)
  while ie LE n_elements(flt_grade)-1 do begin
    asca_grade(ie) = map(flt_grade(ie))
    ie = ie + 1
  end
RETURN, asca_grade
END