namely the Saastamoinen model, Hopfield model and Simplified Hopfield model. In this study, both short and medium
length baseline data sets were tested. In addition, each baseline data set is further divided into two scenarios, flat
terrain and rough terrain. Overall results indicate that there are no statistically significant differences in the
performance of the three tropospheric models. However, the use of the Saastamoinen and the Hopfield models
tends to produce more reliable results than the use of the Simplified Hopfield model.