A Comparative Study of Different Phase Detrending Algorithms for Scintillation Monitoring

Rapid and sudden fluctuations of phase and amplitude in Global Navigation Satellite System (GNSS) signals due to diffraction of the ionosphere phase components when signals passing through small-scale irregularities (less than hundreds meters) are commonly so-called ionospheric scintillation. The aim of the paper is to analyze the implementation and compare the performance of different phase detrending algorithms to improve scintillation monitoring. Three different phase detrending methods, namely, three cascaded second-order high pass filters, six order Butterworth filter conducted by cascading six first-order high pass Butterworth filters, and Fast Iterative Filter (FIF) are considered in this paper. The study exploits real GNSS signals (GPS L1, Galileo E1b) affected by significant phase scintillation effects, collected in early September 2017 at Brazilian Centro de Radioastronomia e Astrofisica Mackenzie (CRAAM) monitoring station and at Adventdalen (Svalbard, Norway) research station. In this study, a software defined radio (SDR) based GNSS receiver is used to process GNSS signals and to implement the aforementioned detrending algorithms.