Error analysis for global positioning system network

The main objective of this paper is to study the influence of some errors effecting GPS observation on a geodetic network established in 1994 in the area surrounding the Gulf of Suez, the south and the middle of Sinai Peninsula. This network was firstly measured three times in 1994, 1995, and 1996 using Trimble 4000 SSE receivers. The date concerning the year 1996 campaign was taken and processed to study the effect of errors on precision for ten baselines with different lengths and in different days during the observation period. Secondly, a comparison study was made between the broadcast and the precise ephemeredes and their effect on the standard deviation values. Thirdly a model for tropospheric delay such as Hopfield model was used to study the effect of using such a model or ignoring it. Also, different elevation mask angles were used. From this paper it was found that precise ephemeredes was very accurate compares to the broadcast ephemeredes especially for lengths more than 150 km. It was proven that dealing with tropospheric effect by using model is highly advocated for high accuracy application. Finally, results showing that in case the estimated zenith delay state equals zero, in addition to increasing the period of measurements applying session time fixed for all baselines and campaign will improve the results.