GAIM uses a physics-based model as the basis for assimilating a diverse set of near real-time ionospheric measurements. The ionospheric specifications and forecasts that GAIM generates are in the form of three-dimensional electron density distributions from 90 km to geosynchronous altitudes (35,000 km). The first operational version of GAIM, which went operational at AFWA in December 2006, assimilated slant-TEC observations from GPS ground receiver sites, bottom-side electron density profiles from ionosondes, and in-situ electron density observations from the operational Defense Meteorological Satellite Program (DMSP).
The new operational version of GAIM can assimilate ultraviolet (UV) observations from DMSP sensors, including the Special Sensor Ultraviolet Limb Imager (SSULI), which has been developed by NRL’s Space Science Division. Scientists at NRLs’ Space Science Division were instrumental in adding these additional assimilative capabilities to the new operational version of GAIM.
Source: Naval Research Laboratory