January 31, 2002

MEMORANDUM TO:  Record
FROM:           Dennis A. Keyser -- NP22
Subject:        Changes to IBM-SP Data Preprocessor (PREPDATA)
                (February 17, 2000 Version -- UPDATE # 10)


The February 17, 2000 data preprocessor program (PREPDATA) was
updated for the tenth time.  UPDATE #10 was implemented on the
IBM-SP machine at 12Z on January 29, 2002.  Except where noted,
the changes below affect all five versions: ETA, AVN, FNL, RUC
and CDAS.

**************** I B M - S P   U P D A T E   # 10 ***************


I. GENERAL CHANGES

     1) Added new PREPBUFR processing step (Table D entry)
ACARSQC into the PREPBUFR mnemonic table.  This will handle
events in the future ACARS quality control program
PREPOBS_ACARSQC.  This step is assigned program code 14.
[BUFRTABLE}

     2) The units for NESDIS recursive filter flag (mnemonic
RFFL) in the PREPBUFR mnemonic table are changed from Code table 
to Numeric since this value is a number ranging from 1-100 as
assigned by NESDIS. [BUFRTABLE]


II. OERATIONAL CHANGES SPECIFIC TO A DATA TYPE

  A. CHANGES TO AIRCRAFT (AMDAR/ASDAR and ACARS) DATA PROCESSING

     1) The precision of temperature observation variable is now
returned in IW3UNPBF in units of degrees K * 100 (category 8,
code figure 915) since it is stored with 10**2 precision in
dumps.  Prior to this, it was stored as degrees K * 1,  with the
incorrect comment that it was a BUFR code table 0-08-005.  The
actual descriptor is 0-02-005. [IW3UNPBF]

     2) Reads precision of temperature observation from "AIRCAR"
and "AIRCFT" BUFR dump files and encodes this into PREPBUFR file
under mnemonic PCAT (BUFR descriptor 0-02-005).  This is needed
by the future ACARS quality control program (PREPOBS_ACARSQC).
[MAIN, GETC06, W3FIZZ, FIZZ01, BUFRTABLE]

     3) Added print for precision of temperature observation.
[MAIN, FILLX]

  B. CHANGES TO MARINE DRIFTING AND MOORED BUOY DATA PROCESSING

     1) RUC only: Corrected an error introduced with an
implementation on 1/9/2001 which resulted in no mass reports
being encoded into the RUC version of the PREPBUFR file for these
data types (affected only the RUC and only these data types). 
This implementation was meant to process moored and drifting
buoys with missing pressure data but valid wind data as PREPBUFR
report type 282 with pressure set to 1013.3 mb (exactly as is
done for ATLAS buoys in the Global system).  While this was
working properly, an error in the logic skipped over the
processing of reports with valid pressure and mass data. [MAIN,
SFCDTA]


  C. CHANGES TO VAD WIND DATA PROCESSING

     1) Effective 00Z 01/31/2002: Subroutine W3UNPKB7 now reads
in the value for ON29 wind quality mark (mnemonic QMWN) on each
level and sets the returned category 4 level wind quality mark to
this value if it is 12 (meaning on reject list) or 14 (meaning
the SDM has purged it).  If it is not 12 or 14 (then most likely
missing), then, as before, the category 4 wind quality mark is
based on a numerical representation of the RMS vector error in
the wind which is also decoded for each level (mnemonic RMSW). 
This change allows the SDMEDIT flags for rejecting or purging VAD
wind level data to be honored. [W3UNPKB7]

     2) Effective 00Z 01/31/2002: Recognizes that subroutine
W3UNPKB7 can return a category 4 level wind quality mark of 12 or
14 (see II.C.1 above) and encodes this value in the PREPBUFR file
for the level wind quality marker (mnemonic WQC).  This change
allows the SDMEDIT flags for rejecting or purging VAD wind level
data to be honored. [MAIN, GETUPA]


  D. CHANGES TO WIND PROFILER DATA PROCESSING

     1) Effective 00Z 01/31/2002: Subroutine W3UNPKB7 now reads
in the value for ON29 wind quality mark (mnemonic QMWN) on each
level and sets the returned category 11 level quality code to 14
if this value is either 12 (meaning on reject list) or 14
(meaning the SDM has purged it).  If it is not 12 or 14 (then
most likely missing), then, as before, the category 11 quality
code is based on the quality code indicator provided from FSL
which is also decoded for each level (mnemonic NPQC) .  This
change allows the SDMEDIT flags for rejecting or purging wind
profiler level data to be honored. [W3UNPKB7]


     2) Effective 00Z 01/31/2002: Recognizes that subroutine
W3UNPKB7 can return a category 11 level quality code of 14 (see
II.D.1 above) and encodes this value in the PREPBUFR file for the
level wind quality marker (mnemonic WQC).  This change allows the
SDMEDIT flags for rejecting or purging wind profiler level data
to be honored. [MAIN, GETUPA]