pro gte_makebin,filename,data,header,units,ADD_TIME=ADD_TIME,_extra=e


   ; raw structure for program converting a data array into a binary file

   ; data must be as read with readdata.pro (vars, obs)
   ; mgs, 04/27/99

; _EXTRA keywords passed to GTE_WRITEBIN:
;        EXPERIMENT_NAME -> A string containing the name of the experiment.
;            This should not be longer than 40 characters since it will
;            be stored together with EXPERIMENT_NUMBER, ORIGINAL_FILE,
;            and REVISION_DATE as first comment line.
;
;        EXPERIMENT_NUMBER -> number of the experiment or flight number
;
;        EXPERIMENT_DATE -> date of experiment
;
;        ORIGINAL_FILE -> filename of original ASCII file
;
;        REVISION_DATE -> data revision date as contained in the
;            file descriptor of a GTE ASCII file.
;
;        COMMENTS -> A string (array) with comments to be stored in the
;            file. If any of the above four keywords is supplied, it
;            will be added to comments as first line.

   if (n_elements(header) eq 0) then begin
      print,'gte_makebin: USAGE  gte_makebin,filename,data,header,units'
      return
   endif

   ; add dummy time variables to data if requested
   if (keyword_set(ADD_TIME)) then begin
      jday = 0.*data[0,*]
      starth = 0.*data[0,*]
      starts = transpose( findgen(n_elements(data[0,*])) )
      stops  = starts + 1.
      tmpdata = [ jday, starth, starts, stops ]
      tmpdata = transpose( [ tmpdata, data ] )
      tmpheader = [ 'JDAY', 'STARTHOUR', 'STARTSEC', 'STOPSEC', header ]
   endif else begin
      tmpdata = transpose(data)
      tmpheader = header
   endelse



   ; create dummy units if not given
   if (n_elements(units) eq 0) then units = replicate('unknown',n_elements(tmpheader))

   ; create variable descriptors
   vardesc = gte_vardesc(n_elements(tmpheader))
   vardesc.name = tmpheader
   vardesc.unit = units

   ; rename ALT to ALTP
   ind = where(tmpheader eq 'ALT')
   if (ind[0] ge 0) then vardesc[ind].name = 'ALTP'


   ; convert missing code to binary standard
   ind = where(tmpdata eq -9.999 OR tmpdata eq -9.9999 OR tmpdata eq -99.999 $
               OR tmpdata eq -999.9 OR tmpdata eq -999.99)
   if (ind[0] ge 0) then tmpdata[ind] = -9.99E30


   ; get data range
   for i=0,n_elements(tmpheader)-1 do begin
      okind = where(tmpdata[*,i] ne -9.99E30)
      dmin = min(data[okind,i],max=dmax)
      vardesc[i].range = [dmin, dmax]
   endfor

; help,vardesc,tmpdata

   gte_writebin,filename,tmpdata,vardesc,_extra=e

   return
end