Zonal Irregularity Drift Characteristics of Ionospheric Scintillations from two closely-spaced Global Navigation Satellite System receivers at an Indian Low Latitude location

The zonal drift velocity of small-scale ionospheric irregularities associated with the equatorial plasma bubbles (EPBs) of a low latitude station K L University campus (16°26’ N, 80°37’ E, 7.78° N dip latitude), Guntur, India is calculated using the spaced receiver method. The cross-correlation technique is used to calculate the drift velocity of the ionospheric irregularities from the carrier to noise ratio (C/N0) observations recorded at global positioning system (GPS) L1 frequency at two different ionospheric monitoring receivers spaced at a distance of 210m which is within the first Fresnel radius. The details of the cross-correlation technique with an example are illustrated. The results show an apparent eastward velocity with a maximum value above 220 m/s at 18:00 UT that decreased gradually towards midnight. The maximum S4 index on the geomagnetically disturbed day in October 2021 reached up to a level of 1. The analysis in this study is towards an improved understanding of drifting characteristics of ionospheric irregularities above the location. This may help in developing a suitable ionospheric scintillation mitigation algorithm for high-performance positioning and navigation accuracy in global navigation satellite system (GNSS) receivers.