July 13, 2005

MEMORANDUM TO:  Record
FROM:           Dennis A. Keyser -- NP22
Subject:        Changes to IBM-CCS Data Preprocessor (PREPDATA)
                (September 9, 2004 Version -- UPDATE # 2)


The September 9, 2004 data preprocessor program (PREPDATA) was
updated for a second time.  UPDATE #2 was implemented on the
IBM-CCS-II machine at 12Z on July 13, 2005.  The changes below affect only
the NAM, GFS and GDAS.

*************** I B M - C C S   U P D A T E   # 2 **************


I.  OPERATIONAL CHANGES SPECIFIC TO A DATA TYPE

   A. CHANGES TO DROPWINSONDE DATA PROCESSING
      
     1) Will now encode a value of 2 into the report subtype (stored in
PREPBUFR under mnemonic TSB).  This allows dropwinsondes to be differentiated
from reconnaissance aircraft in the PREPBUFR file because both have the same
PREPBUFR report type (mnemonic TYP set to 132 for mass and 232 from wind) and
both have the same DUMP/input report type (mnemonic T29 set to 31).

   B.  CHANGES TO RECONAISSANCE DATA PROCESSING

     1) Will now encode a value of 1 into the report subtype (stored in
PREPBUFR under mnemonic TSB).  This allows reconnaissance aircraft to be
differentiated from dropwinsondes in the PREPBUFR file because both have the
same PREPBUFR report type (mnemonic TYP set to 132 for mass and 232 from
wind) and both have the same DUMP/input report type (mnemonic T29 set to 31).