Sudan and South Sudan HF model based on University of Khartoum ionospheric shells and their mathematical derivations

High frequency propagation model for Sudan and South Sudan in term of the optimum frequency was designed based on the International Reference Ionosphere (IRI). The model simulates the effect of changing atmospheric properties during day and night on the Sudanese ionospheric links in term of the optimum frequency. More than 140 HF links in Sudan were investigated on field to verify the model. The model is intended to be integrated with the Global Ionosphere Observatory Network (GIRO).