Study of Method to Compute Ionospheric S4 Index Based on GPS Signal

Ionospheric scintillations are rapid variations in the amplitude and phase of radio signals resulting from density irregularities in the ionosphere. Ionospheric scintillations influence adversely the performance of satellite communication system and the precision of navigation system. In this paper, the traditional computational method of ionospheric S4 index based on GPS signal is analyzed. In view of the insufficiency of the primitive S4 index computational method and the correction method, a new correction method is proposed. In order to test these methods, further study which is based on data from GPS receivers has been made. The result indicates that the primitive S4 index computational method and the correction method are feasible and reliable.