SBAS-derived TEC maps: a new tool to forecast the spatial maps of maximum probable scintillation index over India
With the increase in the use of satellite-based navigation services, the forecasting of L band scintillation has turned out to be of paramount importance as it affects their accuracy and availability. Forecasting the time of occurrence or non-occurrence, strength and probable location of scintillation enables the service providers and users to take appropriate action to mitigate the effects and optimize the services. We use the recently developed method to retrieve TEC from the ionospheric correction data transmitted by the Indian satellite-based augmentation system (SBAS)–GAGAN. By making use of the established linear relation between the dusk time TEC and the maximum probable scintillation intensity (S4max), scintillation forecast maps have been generated as early as 1930 LT. The superposition of actual S4 measurements, obtained from the GAGAN network of receivers, on the forecasted S4max map shows that the actual measurements are less than the predicted S4max except on very few occasions. The potential of the simple technique to predict the 2 D maps of maximum probable scintillation index for the whole night has been demonstrated which with more refinements could evolve into a viable forecast or forewarning system.
KeywordsAmplitude scintillation S4 Satellite-based augmentation system GAGAN TEC EIA region
The data used in the study are part of the GAGAN project, a joint collaboration between AAI and ISRO. S.S. duly acknowledges the AAI for the support and SAC (ISRO) for hosting his position. R.S. duly recognize the National Academy of Sciences Allahabad for the NASI Sr. Scientist position and also director PRL for hosting the positions.
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