A renewed version of the model of the total electron content in the ionosphere, GEMTEC, is pre sented, aimed at an increase in the accuracy of positioning of single frequency equipment of satellite radio navigation systems. The results of testing of this model in comparison with the standard method of compen sation of the ionospheric delay of radio signals using the Klobuchar model are presented. It is shown that the proposed model is much more accurate than the Klobuchar model.