DSS presents a global synoptic set of 6 hourly upper air data reports. These were operationally collected by NCEP. They include radiosondes, pibals and aircraft reports received via the Global Telecommunications System (GTS) and satellite data from the National Environmental Satellite, Data, and Information Service (NESDIS). This data is the primary input to the Global Data Assimilation System (GDAS), which is used to make forecasts and the Global Final Analyses (FNL). It was also a major input for the NCEP/NCAR and ECMWF Reanalysis Projects. NCEP uses Automated Data Processing (ADP), to decode and reformat the GTS reports. The NCEP document Observational Data Processing at NCEP and the NCAR document TN404 An Introduction to Atmospheric and Oceanographic Datasets, (chapter 3) discusses the collection of this data in greater detail.

The ADPUPA data includes land and ship launched radiosondes and pibals. This involves, at 00Z and 12Z, about 900 - 1000 stations, and at 06Z and 18Z (which are mostly pibals), about 300 - 400 stations. Data may be available at up to 20 mandatory levels from 1000mb to 1mb, plus a few significant levels. The AIRCFT data includes flight level reports from commercial, military and reconnaissance sources. There are about 1200 every 6 hours. The SIRSOB data includes infrared sounding data (discontinued in early 1978) The SATWND data includes winds derived from cloud drift analysis. The AIRCAR data includes data from aircraft takeoff and landings (beginning mid 1991) The reports may include pressure, geopotential height, temperature, dewpoint depression, wind direction and speed.

This dataset is in an ASCII character format, known as the NMC Office Note 29 (ON29) format. DSS has collected for users a variety of important usage details.