PRO read_frame, scope, folder, ffile, w, t, s

  ; Read Fits file and header

  file  = scope+'_'+folder+'/'+ffile+'.FITS_FINAL;1' 
  print,file
  frame = readfits( file, fitshead )
  window,0 &  tvscl,frame

  ; Construct wavelength scale and timings from FITS header

  IF scope EQ 'apo'  THEN head_apo,  fitshead, wave, time
  IF scope EQ 'twin' THEN head_twin, fitshead, wave, time

  nwave = n_elements(wave)
  ntime = n_elements(time)
  
  ; Resample each row onto a wavelength scale with
  ; equal increments in log lambda. 

  nw = n_elements(w)
  dw = (w(nw-1)-w(0)) / (nw-1)
  FOR it = 0,ntime-1 DO BEGIN
  resample, wave,frame(*,it),w(0),w(nw-1),dw
  ENDFOR  
    xs=fltarr(nw)
    window,1 &  tvscl,frame(0:nw-1,*)
    FOR iw = 0,nw-1 DO BEGIN & xs(iw)=total(frame(iw,*)) & ENDFOR
    window,2 & plot,w,xs



  ; Combine data with pre-existing data arrays and export
  
  IF keyword_set(t) THEN BEGIN
    IF t(0) GE 0 THEN BEGIN
      t  = [t,time]
      nt = n_elements(t)
      ss = s
      print,"nt, nw, nt*nw ",nt,nw,nt*nw,n_elements(ss)+(ntime*nw)
      s = fltarr(nw,nt)
      s(*,0:nt-ntime-1) = ss     
      s(*,nt-ntime:nt-1) = frame(0:nw-1,*)
    ENDIF ELSE BEGIN
      t = time
       s = frame(0:nw-1,*)
    ENDELSE  
  ENDIF ELSE BEGIN
    t = time
    s = frame(0:nw-1,*)
  ENDELSE



END