SIMPLIFIED IONOSPHERIC REGIONAL MODEL FOR TELECOMMUNICATION APPLICATIONS

A simplified model of the key ionospheric characteristics of vertical incidence such as foF2, M(3000)F2, h'F, foF1, and foE that are used fo r prediction of operational parameters of HF telecommunication systems in a restricted area has been developed. The simplified ionospheric r egional model (SIRM), is based upon the Fourier analysis of the monthl y median values of these characteristics from seven ionospheric statio ns in Europe. It is shown that only 12 dominant Fourier coefficients, expressed as a function of local time (LT), solar activity and geograp hic latitude are sufficient to reproduce the main features of the diur nal, seasonal, and solar cycle behavior of the mid-latitude ionosphere under median conditions. The model is in a very suitable form for dig ital computer calculation of the characteristics for a given position, instant of time, and solar activity.