ABSTRACT
The engineers use various softwares for observation processing and GPS networks, generally everyone who uses a device, he uses softwares with the same brand for the processing of it GPS processing networks by defined default parameters and models. The most outstanding issue is that, it should be understood, the application of which kinds of softwares will help us to gain the desirable accuracy and whether the accuracy of coordinate estimation is acceptable in all commercial softwares or not. In this article, we compared a series of softwares which engineers use for their data processing with powerful scientific software that meanwhile it is too hard and time consuming to learn it. We have considered accuracy and validity of scientific software, which gives acceptable results, as a baseline to see how much errors and difference is between this software and the commercial softwares, so we selected Bernese as a scientific software and LGO, Ashtech Solutions, CGO softwares as commercial softwares and we analyzed them and compared the applied models of the softwares with each other. To do so, we choose a GPS network from Tehran city and discussed it, in order to evaluate the measured accuracy for baselines and also coordinate system that after data processing, it was understood that if the polygon of a network is small, commercial softwares can be utilized with very high acceptable accuracies and even by Ephemerides Precise data, their accuracy will increase more, but if our network is more extended and bigger, there is no other choice except using scientific softwares to calculate coordinate that performs a processing by many parameters.