Line-of-sight electron density gradients as deduced from an empirical ionospheric model

A topside ionospheric model (Bent Ionospheric Model) was developed for an accurate prediction of integrated total electron content (TEC), from a global data acquired for the years 1962 to 1969. In this paper the effects of line-of-sight electron density gradients on ground to satellite measurements are discussed. The results of analyses show that in the presence of increasing density gradients, deduced values of vertical electron content or slab thicknesses will be too large, while for decreasing gradients these values will be smaller than they should be.