Abstract Ionospheric scintillation is quite a common phenomenon over the low latitude regions and in East Africa it is often monitored using measurements from the SCIntillation Network Decision Aid (SCINDA) receivers. The SCINDA receivers over East Africa are characterized by long base lines and data paucity thus offering a huge challenge in the long term scintillation characterization over the region. To alleviate this challenge, we implemented the use of data from the dual frequency GPS receivers of the IGS network in combination with data from the SCINDA receiver at Nairobi, Kenya to model amplitude scintillation. The data from the SCINDA (geographic coordinates 36.808oE, −1.274oN) and GPS (geographic coordinates 36.893oE, −1.221oN) receivers were used to derive S4 index and its proxy respectively. Comparison of the S4 and its proxy revealed a high correlation coefficient between the two datasets. Scintillation occurrence was observed to peak during the equinox months of March–April and September–October. The vernal equinox was observed to have less frequent scintillation events than the autumnal equinox. The local time (LT) scintillation occurrence shows a peak between 20:00 LT and 23:00 LT. An empirical hybrid amplitude scintillation occurrence probability model was then developed. The results show that the model predicted values were in good agreement with the observed amplitude scintillation occurrence probabilities from the SCINDA receiver. This observation suggests that the model is a useful tool for approximating amplitude scintillation occurrence probabilities at L-band frequencies at African equatorial latitudes.

中文翻译：

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GPS 衍生的振幅闪烁代理模型：东非低纬度站的案例

摘要 电离层闪烁是低纬度地区非常普遍的现象，在东非，经常使用 SCIntillation 网络决策辅助 (SCINDA) 接收器的测量值对其进行监测。东非的 SCINDA 接收器具有基线长和数据稀少的特点，因此对该地区的长期闪烁表征提出了巨大挑战。为了缓解这一挑战，我们将来自 IGS 网络的双频 GPS 接收器的数据与来自肯尼亚内罗毕 SCINDA 接收器的数据结合使用，以模拟振幅闪烁。来自 SCINDA（地理坐标 36.808oE，-1.274oN）和 GPS（地理坐标 36.893oE，-1.221oN）接收器的数据分别用于导出 S4 指数及其代理。S4 及其代理的比较揭示了两个数据集之间的高相关系数。观察到闪烁发生在 3 月至 4 月和 9 月至 10 月的春分月份达到峰值。观察到春分比秋分具有更少的闪烁事件。当地时间 (LT) 闪烁出现在 20:00 LT 和 23:00 LT 之间出现峰值。然后开发了经验混合振幅闪烁发生概率模型。结果表明，模型预测值与从 SCINDA 接收机观测到的幅度闪烁发生概率非常吻合。这一观察结果表明，该模型是估算非洲赤道纬度 L 波段频率振幅闪烁发生概率的有用工具。