Ogunjo, Samuel T.Dada, Joseph B.Oluyamo, Sunday S.Fuwape, Ibiyinka A.2021-05-192021-05-192018-11-30http://repository.elizadeuniversity.edu.ng/handle/20.500.12398/995Staff DescriptionSatellite communication systems suffer from the systematic error of tropo- spheric delay. Accurate estimation of this delay is essential for communi- cation budget and planning. This study investigates the tropospheric de- lay in three Nigeria cities: Abuja, Lagos, Port-Harcourt using two different models (Saastominen and Hopfield). Three year atmospheric data for sur- face pressure, relative humidity and temperature obtained at 5-mins 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 season 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 values at high temperature. Theorems were proposed with proofs to explain the relationship observed between the two models.enTRODAN,Saastominen,Hopfield,tropospheric delay,radio refractivityArticle