Fast Dynamic of Polar Ionosphere from GNSS SDR High Sampling Rate Measurements

Software Defined Radio (SDR) receivers are able to process Intermediate Frequency (IF) signals acquired by a front-end in order to generate Global Navigation Satellite Systems (GNSS) In-phase and Quadrature amplitude values at very high sampling rate (up to 1000 Hz). The analysis of GNSS signals at frequencies higher than the usual 50 Hz, provided by the traditional ionospheric scintillation receiver monitor, gives the possibility to describe the dynamics of the scintillation driven irregularities spanning a wider time scales range. In this work, a new spectral decomposition analysis technique named Adaptive Local Iterative Filter (ALIF) is applied to the data provided by a GNSS SDR developed by Politecnico di Torino in order to highlight the contributions to the scintillations characterized by frequencies higher than 50 Hz. The objective is to relate such contributions to the very fast dynamics processes typical of the ionosphere at polar regions that are not caught using the very well known scintillation indices S4 and sf that is calculated on 50 Hz samples. Results on scintillation case events using data from both SDR and Septentrio PolaRxS receivers installed in the South African Antarctica station SANAE IV (71° 40' S, 2° 50' W) in the framework of the DemoGRAPE project are here presented.