الفهرس 
Dissertation AbstractOnly 14 pages are availabe for public view
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Abstract
Introduction: - Recently, Global Positioning System (GPS) has been used widely in various engineering fields especially for survey works by different users. The online services which established and enhancement by various organizations and these sits are easy to use and just need to make a free membership and they have become an alternative choice to the high-cost scientific software which need experience and training to get high accuracy results and commercial software which have a cost lower than the scientific software but give accuracy less than the scientific one, to can get high accuracy results for post processing data of GNSS. When a high accuracy level reach to millimeters (mm) level are wanted to reach, that could be used in various qualities of the engineering applications through these services. Research scope: - This research aims to investigate the accuracy of the commercial software TBC 3.5 and the online services which used in the study (namely CSRS- PPP, APPS, TRIMBLE RTX, OPUS, and AUSPOS). Some of these services use relative solution technique and others use precise point positioning (PPP) solution technique. Research objective: - This thesis will investigate the accuracy of the online service which process the GNSS data and compare it with the commercial software TBC3 3.5 and show how can use the online service to get high accuracy results and show that the services could be a low cost alternative method for post processing the GNSS data with high accuracy level. Steps Study: - In this research, a test studies was done at Europe and Egypt network to investigate the accuracy of the commercial software TBC 3.5 and the online services which used in the study (namely CSRS-PPP, APPS, TRIMBLE RTX, OPUS, and AUSPOS). Some of these services use relative solution technique and others use precise point positioning (PPP) solution technique. In Europe test study, the coordinates of fourteen IGS stations were computed by using different online services and by The International Terrestrial Reference Frame (ITRF) web site which it taken as a reference from 24-hour GPS data in 1/1/2015 set and then the differences between the coordinate from online services and the ITRF web site result are calculated, In Egypt network the coordinates of seven points were computed by using different online services and by OPUS service which used in Egypt network as a reference solution as it give the most accurate results in the test in Europe network for 24-hour GPS data in static mode for tested points the seven points, points namely MNSR, SAID, BORG, ARSH, MTRH, ASWN, and ALAM on 26/1/2014 (epoch 2014.00) were selected for the accuracy analysis and the data- sampling interval was 30 second. Summary of Study:- Accurate positioning by using online service which use relative and precise point positioning technique and commercial software TBC 3.5 in Europe and Egypt network for static data have been extensively investigated in this thesis. This thesis analyzes the accuracy of each online service in fourteen I.G.S station in Europe network comparing to the ITRF web site solution which used as a reference solution to judge each service, then the online services are tested by applying it in seven points in Egypt network and comparing its results to OPUS service to judge it as this service give the best results in Europe network.