Fix some header keywords (CHECKSUM and DATASUM)

fix_fits_header.pro

+pro fix_fits_header, filename
+    fits_info, filename, n_ext = n_ext, /silent
+    for ext = 0, n_ext do begin
+        data = readfits(filename, header, exten_no = ext, /silent)
+        for k = 0, n_elements(header) - 1 do begin
+            while header[k].matches('\/  +') do begin
+                header[k] = header[k].replace('/  ', '/ ')
+            endwhile
+        endfor
+        fits_add_checksum, header, data
+        modfits, filename, 0, header, exten_no = ext
+    endfor
+end
\ No newline at end of file

metis_l1_prep.pro

 pro metis_l1_prep
-
     ; keyword defining if the detector reference frame must be used for the output
 
     ref_detector = 1
@@ -94,7 +93,7 @@ pro metis_l1_prep
 
     obt_beg = fxpar(primary_header, 'OBT_BEG')
     obt_end = fxpar(primary_header, 'OBT_END')
-	obt_avg = (obt_beg + obt_end)/2.0D
+    obt_avg = (obt_beg + obt_end) / 2.0d
 
     date_beg = solo_obt2utc(obt_beg)
     date_end = solo_obt2utc(obt_end)
@@ -282,7 +281,7 @@ pro metis_l1_prep
 
     if datatype le 2 then begin
         nsumexp = ndit * ndit1 * ndit2
-		xposure = dit/1000.D0 * nsumexp
+        xposure = dit / 1000.d0 * nsumexp
         data = long(data) * nsumexp
 
         if ~isa(comment) then comment = !null
@@ -293,7 +292,7 @@ pro metis_l1_prep
         journal, '  nsumexp = ' + string(nsumexp, format = '(I0)')
     endif else begin
         nsumexp = 1
-		xposure = dit/1000.D0
+        xposure = dit / 1000.d0
     endelse
 
     ; adjust the primary header (it is almost the same for all data product types)
@@ -360,7 +359,6 @@ pro metis_l1_prep
     empty_params = !null
 
     if datatype eq 0 or datatype eq 3 or datatype eq 5 then begin
-		
         ; patch to fix the lack of the keyword SEQ_NUM
 
         pol_id = fxpar(primary_header, 'POL_ID', missing = 0)
@@ -561,6 +559,10 @@ pro metis_l1_prep
 
     journal, 'HK binary-table extension correctly added.'
 
+    ; fix some header keywords
+
+    fix_fits_header, out_file_name
+
     ; unload the spice kernels
 
     load_spice_kernels, kernel_list = kernel_list, /unload