Neural network based TEC model using multistation GPS-TEC around the northern crest of equatorial ionization anomaly

The highest Total Electron Content (TEC) values in the world normally occur at Equatorial Anomaly region resulting in largest ionospheric range delay values observed for any potential SBAS system. The location and magnitude of the very high TEC values are directly related to the strength of the Equatorial Electrojet (EEJ) on day to day basis. The day to day variability of the location of the anomaly peak and its intensity is very large. This imposes severe limitations on the applicability of commonly used ionospheric models to the low latitude regions. A model is developed based on real time low latitude GPS-TEC data measured around the northern crest of the Equatorial Ionization Anomaly (EIA) during 2007 through 2011. This model is compared with standard ionospheric models like International Reference Ionosphere (IRI) and Parameterized Ionospheric Model (PIM) to establish its utility and applicability in the equatorial region for accurate predictions.