Automatic ionospheric scintillation detector for global navigation satellite system receivers

Severe ionosphere scintillations have been known to affect the performance and measurement accuracy of Global Navigation Satellite System (GNSS) receivers. The scintillation in signal amplitude and phase reduces the number of available GNSS satellites by causing the loss of lock in GNSS receivers. Hence, the investigation of ionospheric scintillations is imperative for monitoring the activities of the atmosphere, ionosphere and space weather. Scintillations can be modelled as a function of scintillation indices like amplitude scintillation index (S4), phase scintillation index (σØ), C/N and elevation angle with respect to the time. In this study, the GNSS Ionospheric Scintillation and TEC monitor receiver located at the K L University, Vaddeswaram, India, sited in low latitudes, provided the data for the real-time analysis of ionospheric scintillations. This paper describes an ionospheric scintillation model (RTISM), which determines the automatic threshold for different scintillation signals using the Neyman Pearson detector. The results of the RTISM model include estimation, detection and mitigation of ionospheric scintillations using wavelet analysis, Hilbert-Huang transform and binary hypothesis test. The RTISM model has been tested for major scintillation events observed during the geomagnetic storms that occurred in the maximum solar activity periods of the 24th solar cycle (2013-2014).