September 21, 2001 MEMORANDUM TO: Record FROM: Dennis A. Keyser -- NP22 Subject: Changes to IBM-SP Data Preprocessor (PREPDATA) (February 17, 2000 Version -- UPDATE # 7) The February 17, 2000 data preprocessor program (PREPDATA) was updated for the seventh time. UPDATE #7 was implemented on the IBM-SP machine at 12Z on September 25, 2001. 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 # 7 *************** I. OPERATIONAL CHANGES SPECIFIC TO A DATA TYPE A. CHANGES TO RADIOSONDE DATA PROCESSING 1) Corrected an error in calculating radiosonde balloon drift d-time (balloon drift time minus PREPBUFR center time) for wind report pressure levels that are also found in the corresponding mass report. This time has always been calculated correctly for the mass report levels. This is encoded into the PREPBUFR file under mnemonic HRDR but is currently assimilated only by the GBL-SSI. [MAIN, FIZZ01] B. CHANGES TO SURFACE LAND AND MARINE PROCESSING 1) The report sequence number (encoded in the PRPEBUFR file header under mnemonic SQN) is now processed separately for surface land and marine reports. Prior to this, it was missing. This is not used by any analysis, but is useful for combining mass and wind reports for the same observation (since they have the same unique sequence number). [MAIN, SFCDTA] C. CHANGES TO SATELLITE-DERIVED WIND REPORT PROCESSING 1) The report sequence number (encoded in the PRPEBUFR file header under mnemonic SQN) is now processed for all satellite wind reports. Prior to this, it was missing. This is not used by any analysis, but is useful for combining mass and wind reports for the same observation (since they have the same unique sequence number). Currently this is not an issue since only wind data is processed for these data. [MAIN, GETC06] D. CHANGES TO RECONNAISSANCE DATA PROCESSING 1) The report sequence number (encoded in the PRPEBUFR file header under mnemonic SQN) is now processed separately for these data. Since they are included at the end of the ADPUPA message type in the PREPBUFR file, the sequence number of the LAST RAOB/PIBAL/DROPWINSONDE report processed earlier is stored in COMMON and the sequence numbers for the reconnaissance reports pick up from that point. This ensures that all reports in the ADPUPA message type have a unique sequence number. Prior to this, sequence number was missing for these data. This is not used by any analysis, but is useful for combining mass and wind reports for the same observation (since they have the same unique sequence number). [MAIN, STOROB, GETC06]