The study examined the ionospheric total electron content (TEC) variation based on global navigation satellites system (GNSS) stations located inside the Arabian Peninsula. An interpolation technique known as cubic spline is used and numerical investigation of TEC variation has been carried out from 2015 to 2017. First, global ionospheric map (GIM) data is interpolated with the help of the cubic spline interpolation method and then compared with observed GNSS TEC values. Correlation coefficients between observed and interpolated GIM TEC are very high (about 0.95), indicating a strong relationship. Normal correlation coefficients were not enough to establish their relationship; hence, the wavelet plot of the first four principal components of each series is plotted and again their correlation coefficients are studied. Although their correlation is good enough, the wavelet analysis points out the variability of each series, that they are not quite same. The low and high peaks of each series are different; which means, the lowest and highest peaks of both series do not occur at the same time. This can happen because there are few international GNSS service stations available over the Arabian Peninsula that becomes a cause of error in the interpolation of GIM data. This type of study indicates only simple comparisons such as correlation coefficient and a standard deviation is not enough for comparative analysis; we need to study it in depth by using suitable statistical tools.

该研究基于位于阿拉伯半岛内的全球导航卫星系统 (GNSS) 站检查了电离层总电子含量 (TEC) 的变化。使用称为三次样条的插值技术，并对 2015 年至 2017 年的 TEC 变化进行了数值研究。 首先，借助三次样条插值方法对全球电离层图 (GIM) 数据进行插值，然后与观测到的 GNSS 进行比较TEC 值。观察到的和内插的 GIM TEC 之间的相关系数非常高（约 0.95），表明存在很强的相关性。正态相关系数不足以建立它们的关系；因此，绘制了每个序列的前四个主成分的小波图，并再次研究了它们的相关系数。虽然它们的相关性足够好，但小波分析指出每个序列的可变性，它们并不完全相同。每个系列的低峰值和高峰值不同；这意味着，两个系列的最低和最高峰值不会同时出现。之所以会发生这种情况，是因为阿拉伯半岛上可用的国际 GNSS 服务站很少，这会导致 GIM 数据插值出现错误。这种类型的研究表明，只有相关系数和标准差等简单比较不足以进行比较分析；我们需要使用合适的统计工具对其进行深入研究。两个系列的最低和最高峰值不会同时出现。之所以会发生这种情况，是因为阿拉伯半岛上可用的国际 GNSS 服务站很少，这会导致 GIM 数据插值出现错误。这种类型的研究表明，只有相关系数和标准差等简单比较不足以进行比较分析；我们需要使用合适的统计工具对其进行深入研究。两个系列的最低和最高峰值不会同时出现。之所以会发生这种情况，是因为阿拉伯半岛上可用的国际 GNSS 服务站很少，这会导致 GIM 数据插值出现错误。这种类型的研究表明，只有相关系数和标准差等简单比较不足以进行比较分析；我们需要使用合适的统计工具对其进行深入研究。