PRO head_apo, fitshead, wave, time

  ; extract keywords from APO header and decode
  ; to obtain wavelength and timeing arrays


  nwave =  FXPAR(fitshead, 'NAXIS1')
  wave   = fltarr(nwave)


  w0 =  FXPAR(fitshead, 'WAVE_0')
  w1 =  FXPAR(fitshead, 'WAVE_1')
  w2 =  FXPAR(fitshead, 'WAVE_2')
  w3 =  FXPAR(fitshead, 'WAVE_3')
  w4 =  FXPAR(fitshead, 'WAVE_4')
  FOR iw = 0,nwave-1 DO BEGIN
   wave(iw) = w0 + w1*iw + w2*iw*iw + w3*iw*iw*iw + w4*iw*iw*iw*iw
  ENDFOR
  wave = alog10 (wave) 
    print,w0,w1

  ntime = FXPAR(fitshead, 'NAXIS2')
  time  = dblarr(ntime)

  ; sort times out !!!!

  obsdate = FXPAR(fitshead, 'DATE-OBS')
    obs = date_conv(obsdate,'V')
  ;  print,obs
    ydn2md,obs(0),obs(1),mth,day
    ;  conversion from OBSDATE (TAI) into UTC
    ut0 =  obs(2) + (obs(3)+(obs(4)-32.)/60.)/60.  ; hours
    ;  extraction of julian date
    jdcnv, obs(0), mth, day, ut0, jd
      j0 = floor(jd-0.5) - 2452000. ; days

  dt =  FXPAR(fitshead, 'TIME_STE')

   ;  print,obs(0),mth,day,jd,j0,ut0,dt

  FOR it = 0,ntime-1 DO BEGIN
    time(it) = j0 + ut0/24. + ( dt*it ) / 86400.
  ENDFOR

END