The SSUSI Ground Data Analysis Software will create SSUSI Sensor Data Records (SDRs) and Environmental Data Records (EDRs). The SDRs contain data directly measured by the sensors, such as photometer counts, uncertainties, light intensities and pointing information derived from the SSUSI raw sensor data, the DMSP Satellite ephemeris data, and data obtained from the Air Force relational databases. The EDRs contain environmental parameters which are derived from the sensor data< by scientific algorithms specific to day, night, and auroral regions.

All SSUSI data products contain a file header. The SSUSI GDAS standard header uniquely identifies each SDR & EDR file, by date, universal time and position at start and end of each quarter orbit segment, 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 SSUSI SDR files will be stored in quarter orbit increments according to the satellite number (for one of five DMSP Block 5D-3 or higher satellites), date, revolution number, and quarter orbit. SDR files consist of pairs of records, except for the End-of-File record. Record pairs consist of a Record Type Indicator Record and a data record of the indicated type.

SDRs contain the calibrated, gridded, geolocated sensor data. The SDR data are gridded in increments of along-track orbit angle, phi, and either

• cross-track nadir angle, theta for image data,
• spectral wavelength, lambda for spectrograph data, or
• no lateral grid increments for photometer data.

The data stored in each SDR user grid pixel has data from any overlapping scan pixels averaged. The number of pixels in a quarter orbit disk grid and hence is 22,848 when in full scan mode (408 pixels along track x 56 across track) and 17,952 in reduced scan mode (408 along track x 44 across track). The quarter orbit limb grid has 408 pixels along-track with 24 altitudes in the profile at each pixel. The maximum number of records in the SDR files is equal to the number of pixels or pixel-profile elements, respectively. All latitudes and longitudes in the files are geodetic.

The SSUSI EDR Files will be produced for all day, night and auroral region SDRs in image mode. EDRs will be stored in quarter orbit increments according to the satellite number, for one of five DMSP Block 5D-3 or higher satellites, date, revolution number, and quarter orbit.

EDRs are the gridded geolocated environmental parameters derived from the SDRs. EDR pixels are regridded from the SDR pixels. A single EDR pixel may consist of as many as 16 SDR pixels. All latitudes and longitudes in the files are geodetic coordinates.

When all pixels are either day, night, or auroral, the maximum number of records that may occur in EDR files, is as follows:

The Disk EDR file is composed of pairs of records, except for the End-of-File record. A record pair consists of a 'record type indicator record' and a 'data record'. The type and number of record in a file depend on the type of pixels in an EDR grid and presence of valid data products, along with a SSUSI header record and an End-of-File record. The pairs of records for day disk data occur in the file after the entire day record, followed by auroral data pairs, and night disk data pairs, if data of those type are present in the EDR grid.

The Limb EDR file does not contain auroral boundary data. It contains profile level altitudes, pairs of day limb data, night limb data, and an End-of-File record.