The SSUSI Ground Data Analysis Software creates SSUSI level 1B data (geolocated, calibrated, background subtracted instrument resolution radiances), grids that data into SSUSI Sensor Data Records (SDRs), and then uses the gridded data to retrieve environmnetal parameters in Environmental Data Records (EDRs). The algorithms for each stage of the processing are described in the SSUSI Data Product Algorithm Documentation. This documentation describes in some detail the data preparation and retrieval algorithms used in the SSUSI GDAS.
All SSUSI data products contain a file header. The SSUSI GDAS standard header uniquely identifies each L1B, SDR, & EDR file, by date, universal time and position at start and end of each data product, instrument mode, as well as regions included (auroral, day, and/or night), solar index and related activity level, and geomagnetic index and related activity level. The header also contains versioning information about software, product, and calibration versions applied to the data.
The SSUSI data products are generally divided by location (disk and limb parts of the scans are separated and processed separately), and region (day, night, or auroral). These divisions serve to define the different data products. Within the EDRs, further refinements are made to ensure that the environment where the routines are applied are valid for the algorithm. There are Data Quality Indices (DQI) in the data products that indicate where the algorithms may be outside the range of verified validity. The variables inside the file are described in the Data Format section.