“…To improve on estimations of climatologic models and still obtain a full 3-D picture of the ionosphere, tomography techniques have extensively been applied (e.g., Hong et al, 2017;Raymund et al, 1990;Saito et al, 2016;Seemala et al, 2014;Ssessanga et al, 2015Ssessanga et al, , 2017Tsai et al, 2002). However, ionosphere tomography techniques have a deficiency of not being able to adequately spread observation information within the grid, specifically over remote areas where measurements are lacking.…”