Satellite communication systems suffer from the systematic error of tropospheric delay. Accurate estimation of this delay is essential for communication budget and planning. This study investigates the tropospheric delay in three Nigeria cities: Abuja, Lagos, Port Harcourt using two different models (Saastominen and Hopfield). Three-year atmospheric data for surface pressure, relative humidity and temperature obtained at 5-min interval were acquired from the Tropospheric Data Acquisition Network (TRODAN) archives. Computed radio refractivity values showed distinct seasonal dependence in Abuja with low and high values during the dry and wet seasons respectively. The Hopfield model predicts higher hydrostatic delay values than the Saastominen model. In the non-hydrostatic delay, the two models converge to a single value at high temperature. Theorems were proposed with proofs to explain the relationship observed between the two models.

卫星通信系统遭受对流层延迟的系统误差。准确估计此延迟对于通信预算和规划至关重要。本研究使用两种不同的模型（萨斯托米宁和霍普菲尔德）调查了尼日利亚三个城市的对流层延迟：阿布贾、拉各斯和哈科特港。从对流层数据采集网络 (TRODAN) 档案中获取以 5 分钟为间隔获得的三年大气数据，包括表面压力、相对湿度和温度。计算的无线电折光率值在阿布贾显示出明显的季节性依赖性，分别在旱季和雨季具有低值和高值。Hopfield 模型预测的流体静力延迟值高于 Saastominen 模型。在非流体静力延迟中，两个模型在高温下收敛到一个值。