Analysis of Ionospheric Scintillations Measurement on NavIC Signals

Ionospheric scintillation is a rapid change in amplitude and phase of an electromagnetic signal in the ionospheric environment. Amplitude scintillations indicated by S4 index and phase scintillations by. Low latitude regions are prone to ionosphere scintillation. Since India is a low latitude region, ionospheric scintillations must be analysed. Indian NavIC or IRNSS planned and implemented by the Indian Space Research Organization (ISRO). In this paper S4 index is investigated for NavIC L5 (1.17645 GHz) and S1 (2.492028 GHz) signals (1B,1C,1D,1E,1F,1G). For the analysis Guntur station (Lat:16.44N, Lon:80.62E) and Hyderabad station (Lat:17°24’28.10″N, Lon: 78°31′4.22″E) IGS receiver data is considered. The S4 index is calculated using carrier to noise ratio of IRNSS L5 and S band signals. From the results it is observed that S4 index is more for L5 band signals compared to S band signals, as ionospheric scintillations are frequency dependent. Guntur station S4 average value is low for all (L5 and S) band satellite signals compared to Hyderabad station satellite signals. Over Indian region, it shows latitude-dependent scintillations.