The existing global network of continuously operating stand-alone GNSS reference stations provides an opportunity to estimate total electron content (TEC) from raw Global Positioning System (GPS) measurements. The TEC driven from a local GPS network in Pakistan was compared to two international models: IRI-2016 and IRI-PLAS 2017. The performance was analyzed statistically based on residual analysis, RMSE and correlation. It is observed that the TEC estimated by all three methods follows the same diurnal trend where it maximizes around noon (\(12:00 {-} 14:00 LT\)) and reduces in the afternoon (\(15:00 {-} 17:00 LT\)). Both empirical models provide a better estimation of nighttime TEC as compared to daytime TEC and exhibit maximum deviation in the month of April with the lowest deviation in December. The IRI-2016 underestimates TEC by \(5 - 10 TECU,\) whereas the IRI-PLAS 2017 overestimates TEC by \(10 - 22 TECU\). However, the IRI-2016 conforms better to GPS-TEC (\(\overline{\gamma } = 0.9710\)) as compared to IRI-PLAS 2017 (\(\overline{\gamma } = 0.8337\)). The study shows that local GNSS stations in collaboration with TEC estimated from global models may be used in development of an efficient local TEC model over Pakistan which will not only assist in local ionosphere studies but also aid in improving the positioning accuracy.

连续运行的独立GNSS参考站的现有全球网络为从原始全球定位系统（GPS）测量值估算总电子含量（TEC）提供了机会。将来自巴基斯坦本地GPS网络的TEC与两个国际模型进行了比较：IRI-2016和IRI-PLAS2017。对性能进行了基于残差分析，RMSE和相关性的统计分析。可以观察到，通过这三种方法估算的TEC都遵循相同的昼夜趋势，即在中午左右（\（12:00 {-} 14:00 LT \））最大化，而在下午（\（15:00 {- } LT 17：00 \））。与白天的TEC相比，这两种经验模型都提供了更好的夜间TEC估算值，并且在4月份呈现最大偏差，而12月份呈现出最小偏差。IRI-2016低估TEC为\（5-10 TECU，\），而IRI-PLAS 2017高估TEC为\（10-22 TECU \）。然而，IRI-2016符合更好的GPS-TEC（\（\划线{\伽马} = 0.9710 \） ）相比，IRI-PLAS 2017（\（\划线{\伽马} = 0.8337 \） ）。研究表明，与全球模型估计的TEC配合使用的本地GNSS台站可用于在巴基斯坦上开发有效的本地TEC模型，这不仅有助于当地电离层研究，而且有助于提高定位精度。