Ionospheric providing of HF propagation in high latitudinal regions

For HF propagation providing, it is necessary to have the information on an ionospheric condition. The paper purpose was the estimation of possibility to use the IRI model in a high-latitude zone according to vertical and oblique sounding. It is shown that the new version IRI2016 of the model provides conformity of the modeling values of foF2 with experimental medians at level of middle-latitude values. Calculations of oblique ionograms were performed by a ray tracing method for two days 26.01.2016 (UT = 11:20) and 25.02.2016 (UT = 10:20) to which data were available. The greatest number of paths (17) was 25.02. The following results are obtained for these paths. For the initial IRI model, relative deviations of MUF from observational values MOF were 14.53% and 15.75% for one and two hops. Adaptation of the IRI model to data of current diagnostics has provided 7.93% and 6.68%. As foF2, SPIDR database was used, at absence - data of TEC. These estimates lay in limits for middle-latitude zones. Thus, in this case (quiet geomagnetic conditions) the initial IRI model provides acceptable results. Its adaptation to data of current diagnostics of vertical sounding and measurements of TEC allows increasing accuracy of MUF determination in 2 times.