Effect of Grid Size Variation on the Interpolation of the Total Electron Content over the Indian Region

Abstract

Satellite Based Augmentation Systems (SBAS) for navigational services rely heavily on the accurate estimation of the Total Electron Content (TEC) along the slant ray path. The Wide Area Augmentation System (WAAS) estimates and transmits the delay corrections by assuming a 5Â5 degree ionospheric grid (in latitude and longitude) at 350 km altitude using a single shell model. The user interpolates these delay values at his/her position using bilinear interpolation. In this paper, the effect of the variation of grid size on the interpolation of the TEC is analyzed using TEC data from the year 2005. It is observed that the reduction of grid size from 5Â5 to 1Â1 degree and the choice of Kriging technique to interpolate the TEC both at the IGP as well as at the user side result in more accurate estimation of the delay for the GPS Aided Geo Augmented Navigation (GAGAN) system over the Indian region.

Obtaining Ionospheric Conditions according to Data of Navigation Satellites

“…In view of importance of this parameter, the great attention is given to increase of accuracy of its determination (e.g. [5,6]). More exact determination of the ionospheric parameters is returned for more exact navigation decision (e.g.…”