Simultaneous Observations of the Effects of Ionospheric Scintillations on GPS and EGNOS Signals over Equatorial Africa

This study simultaneously observes the impacts of ionospheric scintillations on GPS and EGNOS satellites signals over equatorial Africa. The data set covers January-December, 2013 at three stations; namely, Cape Verde Island, Dakar (Senegal) and Addis Ababa (Ethiopia). We suppressed multipath effects on the data by imposing a 30(0) elevation masking on the data. In another sets of the data, with the view of investigating the impacts of scintillations on the signals from each satellite, we binned the data on a satellite-by-satellite basis, considering all elevation angles. Overall, scintillation occurrences recorded the highest at Cape Verde, followed by Dakar, and least at Addis Ababa, making latitudinal dependence of scintillations evident. Furthermore, the coastal stations recorded higher scintillations than the land-locked station. Generally, on a seasonal note, scintillations recorded highest occurrences during equinoxes; during September equinox at Cape Verde and Dakar and during March equinox at Addis Ababa. The least occurrences were recorded during June solstice. Correspondingly, EGNOS satellites signals scintillated at Dakar and Addis Ababa during the time intervals when GPS satellites signals experienced scintillations. These results could support GPS and EGNOS service providers and designers, with a view to providing robust services for the African user community.