ABSTRACT

This paper examines the accuracy of the Global Positioning System (GPS) within the African low-latitude sector. We evaluated the vertical and horizontal of the single-point positioning (SPP) accuracy of GPS and critically analysed the effects of the equatorial ionospheric anomaly (EIA) over the region of study. Our results imply that using single-frequency GPS for any application could give a positioning error up to 45.00 m vertically and ~25.00 m horizontally. The study revealed that 54% of GNSS positioning errors during the night-time could be linked to ionospheric plasma irregularities. Also, positioning errors are higher in western Africa than in the eastern region. The influence of geomagnetic activities is not consistent with GPS positioning accuracy. However, positioning errors are lower during geomagnetically disturbed conditions in comparison to quiet conditions. The unique phenomena of the EIA can severely limit GPS services at night-time for positioning in the study area.

摘要

本文检验了全球定位系统 (GPS) 在非洲低纬度地区的准确性。我们评估了 GPS 单点定位 (SPP) 精度的垂直和水平精度，并严格分析了赤道电离层异常 (EIA) 对研究区域的影响。我们的结果表明，在任何应用中使用单频 GPS 可能会产生高达 45.00 m 的垂直定位误差和 ~25.00 m 的水平定位误差。该研究表明，夜间 54% 的 GNSS 定位误差可能与电离层等离子体不规则性有关。此外，西非的定位误差高于东部地区。地磁活动的影响与GPS定位精度不一致。然而，与安静条件相比，地磁干扰条件下的定位误差更低。EIA 的独特现象会严重限制夜间 GPS 服务在研究区域的定位。