HF radio channel simulation in the presence of the ionospheric F1 layer

Experience has shown that there are many occasions when HF propagation model performance is degraded because of difficulties surrounding the characterization of the F1 region of the ionosphere. This paper presents a brief description of the F1 layer and approach to ionogram simulations with the presence of F1 layer. The data obtained from [http://giro.uml.edu/didbase/scaled.php] GIRO website were used in simulations.