DSS presents a global synoptic set of 6 hourly upper air reports operationally collected by the National Centers for Environmental Prediction (NCEP). These include radiosondes, pibals and aircraft reports from the Global Telecommunications System (GTS) and satellite data from the National Environmental Satellite, Data, and Information Service (NESDIS). The reports can include pressure, geopotential height, temperature, dewpoint depression, wind direction and speed. This data is the primary input to the Global Data Assimilation System (GDAS), which is used to make forecasts and the Final Analyses (FNL). DS353.4 has been derived from this dataset since April 2000.

The ADPUPA data includes land and ship launched radiosondes and pibals. This involves, at 00Z and 12Z, about 650 - 1000 stations, and at 06Z and 18Z (which are mostly pibals), about 150 - 400 stations. The counts have declined in recent years. Data may be available at up to 20 mandatory levels from 1000mb to 1mb, plus a few significant levels. The AIRCFT data includes commercial, some military and reconnaissance reports. They are flight level reports, numbering about 400 at 12 hourly intervals to, more recently, about 20000 at 6 hourly intervals. The SATWND data includes winds derived from cloud drift analysis. The AIRCAR data includes data from aircraft takeoff and landings, with between 5000 and 10000 reports every 6 hours.

This dataset is maintained in NCEP BUFR format, and updated monthly by DSS using weekly files prepared by NCEP. Software which extracts data from the BUFR file, and places it into a basic text file can be found in BUFRdecode_ADPuprair.tar. Data archived within this dataset spans the period from April 2000 to near current. DS353.4 provides the same data from 1973 to near current in NMC Office Note 29 (ON29) format. BUFR format reports contain additional information that is not carried over to ON29 format, including the the original raw GTS string reports.

NCEP does some operational Quality Control (QC) on the data which sets some QC flags in the reports to qualify, but not quantify any corrections. After the data is used to prepare the FNL analyses, no additional corrections are made. Older data is not reprocessed with newer procedures.

More information is available.