Spectral analysis of ionospheric phase scintillations using Hilbert — Huang transform at a low-latitude GNSS station

Radio frequency signals can be affected by different propagation impairments like rain attenuation, tropospheric scintillation, water vapour attenuation, cloud attenuation, and ionospheric scintillations. At L-band frequencies (1GHz-2 GHz), ionospheric scintillations are predominant and cause variations in the amplitude and/or phase of the GPS signals. In this paper, the Hilbert - Huang Transform (HHT) method has been proposed for mitigating the phase scintillation effects on GPS signal. Ionospheric data collected at KL University, Guntur have been considered for studying the effect of phase scintillations. The obtained results have been validated and compared with the results of the Wavelet Transform technique. The performance of HHT has been observed to be better than wavelet transform in reducing the scintillations.