Comparison of theoretical scintillation spectra with equatorial GNSS data

The ionosphere influence on radio electric signals propagating from a satellite to the Earth can lead to rapid amplitude and phase variations for the receiver : the ionospheric scintillation. We developped an analytic propagation model to link the parameters of the ionosphere to the statistical quantities usually used to describe the ionospheric scintillation, especially the log-amplitude and phase spectra at the receiving end. That model is developped under the Rytov approximation. It is then valid for weak-scattering regime. The undesired effects brought by the processing of the signal at the receiver are modeled and quantified so that we are able to compare experimental data to our propagation model. Particularly, SAGAIE network is composed of several GNSS receivers on each side of the geomagnetic equator, an area significantly impacted by ionospheric scintillation. Ionospheric indices were processed and collected as well as amplitude time series, which can be processed to derive log-amplitude spectra. After a first analysis of the experimental data, we use our analytic model to retrieve the shape of the measured spectra and therefore assess the model's capacity to reproduce real measurements.