Articles | Volume 35, issue 1
Ann. Geophys., 35, 1–9, 2017

Special issue: The 14th International Symposium on Equatorial Aeronomy

Ann. Geophys., 35, 1–9, 2017

Regular paper 03 Jan 2017

Regular paper | 03 Jan 2017

Signature of ionospheric irregularities under different geophysical conditions on SBAS performance in the western African low-latitude region

Oladipo Emmanuel Abe1,2, Xurxo Otero Villamide1, Claudia Paparini1, Rodrigue Herbert Ngaya1, Sandro M. Radicella1, and Bruno Nava1 Oladipo Emmanuel Abe et al.
  • 1The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
  • 2Department of Physics, Federal University Oye-Ekiti, Oye-Ekiti, Ekiti State, Nigeria

Abstract. Rate of change of TEC (ROT) and its index (ROTI) are considered a good proxy to characterize the occurrence of ionospheric plasma irregularities like those observed after sunset at low latitudes. SBASs (satellite-based augmentation systems) are civil aviation systems that provide wide-area or regional improvement to single-frequency satellite navigation using GNSS (Global Navigation Satellite System) constellations. Plasma irregularities in the path of the GNSS signal after sunset cause severe phase fluctuations and loss of locks of the signals in GNSS receiver at low-latitude regions. ROTI is used in this paper to characterize plasma density ionospheric irregularities in central–western Africa under nominal and disturbed conditions and identified some days of irregularity inhibition. A specific low-latitude algorithm is used to emulate potential possible SBAS message using real GNSS data in the western African low-latitude region. The performance of a possible SBAS operation in the region under different ionospheric conditions is analysed. These conditions include effects of geomagnetic disturbed periods when SBAS performance appears to be enhanced due to ionospheric irregularity inhibition. The results of this paper could contribute to a feasibility assessment of a European Geostationary Navigation Overlay System-based SBAS in the sub-Saharan African region.