Some Results on the Nonparametric Statistics of GPS Signal Scintillation

The study of ionospheric scintillation belongs to the class of problems dealing with wave diffraction and propagation through a random medium, and its complete theoretical solution is presently not available. Approximate solutions or models, such as the 'thin phase diffraction screen model' and the 'Rytov solution for weak scintillation', have been proposed and do apply under restrictive conditions. Some probability density functions (PDF) have been derived analytically, or semi-analytically, from the proposed models, such as log-normal, Rician and Nakagami functions for the amplitude scintillation and the normal function for phase scintillation, but all show some discrepancies to the measured scintillation histograms.