CALL SEQUENCE...
       spgdev  SPIN SPOUT OUTPUT
 
 
      DESCRIPTION...
       spgdev - SETS SPECTRAL MEANS TO ZERO
 
 
      AUTHOR  - S.Lambert, SEPT 1979.
      LAST REVISION: $Header: Autres-corrections-d-usages-de-MAXW-NWDS-modifs-dans-GGSIGN-SIGNAG @ 2018-06-05 17:00:06 -0400 (dugas) $
 
 
      PURPOSE - SETS THE SURFACE MEAN OF EACH FIELD IN A SPECTRAL FILE 
                TO ZERO LEAVING THE DEVIATION FROM THIS MEAN.
 
 
      INPUT FILE...
       SPIN  = GLOBAL SPECTRAL FIELDS
 
      OUTPUT FILE...
       SPOUT = DEVIATION OF SPECTRAL FIELDS
 
 
      EXIT CONDITIONS...
        0 NO PROBLEMS
        1 PROBLEMS READING SPIN