MOF/MUF behavior over one European path

Many applications of HF propagation via the ionosphere (e.g. bearing-fingers, single station location, emergency systems and so on) demand an accurate description of ionospheric conditions. The International Reference Ionosphere (IRI) model is very often used for such a description. A lot of publications were devoted to the verification and improvement of this model. But most of them were based on data from vertical sounding (VS). Not so many comparisons with oblique sounding results have been reported. Specifically, this concerns parameters of the maximum usable frequency (MUF) and a ground range, D. In this paper errors of MUF and D determination by means of the IRI model are estimated on the example of the MOF data on Inskip-Rome path for December 2003. Adaptation of the model to current conditions by means of VS and total electron content TEC-GPS data is used to reduce these errors.