A.M. Batakov

It is offered to introduce the notion of the efficiency of the ionosphere models with the reference to the conditions of propagation of decametre radio waves on the ionosphere paths. In this work, model characteristics are determined in terms of the maximum usable frequency (MUF). Two paths are chosen: Magadan - Irkutsk path and Norilsk - Irkutsk path. As standard models, experimental values on these paths are chosen that are obtained by method of tilted sounding. As models, whose efficiency is valued, we chose domestic model MUF of the long-term prediction and international model IRI. The data of the measurements for two days is processed by the formation of two arrays of the relative differences between the experiment and model. These arrays are scaled by calculations of two statistical invariants - average and dispersions. The nonlinear formula of the estimation of the efficiency, concluded in interval [0;1 ], is in the form of differences between unity and square root from amount of the square average and dispersions. The result of the calculation of the efficiency for two day intervals on the two paths show that all its values are comprised in interval [ 0,73; 0,87 ]. That is to say it is high enough for calm ionosphere ( Kp ≤ 3, no flashes ). It is essential that differences of the efficiency of the named models are not great: < 0,04. It is important that the experimental measurements of MUF have regular and casual variability. To estimate this factor, we calculated values of efficiency for experimental values of smoothed ( for 3 hours ) daily path of MUF. These values that are named autoefficiency in the work are so far closer to unity and are comprised within [ 0,93; 0,96 ]. The main conclusion of the work is that for calm ionosphere and one-hop paths the efficiency of the models of domestic MUF prediction and IRI model are similar to one another.