• Overview popular GNSS systems in the world and their development in the future in order to select the GNSS system that is suitable for Vietnam. Moreover the selected GNSS system aims to be suitable for monitoring construction subsidence that is built on the coastal regions.
• Research and propose the process of application the high accuracy GPS technology for monitoring construction movement. Implement of the process for surveying and calculating the movement in Cam Pha Cement company. 

Theorerical results

• The GNSS systems in the world included: GPS from USA, GLONASS from Russia, and 2 building systems are GALILEO from Europe, COMPASS from China. These GNSS systems are included 3 parts: space segment, control segment, use segment. Each system has particular characteristics as well as advantages and disadvantages. For Vietnam, the application GNSS systems for determination location and navigation by integrating all of 4 systems above is the good choice in the future.
• Propose the process of application of high accuracy GPS technology for monitoring coastal constructions movement. In this case, the survey network is divided to 2 level based on the level of stability of the foundation: control points and monitoring points. The 2 phase receivers for high accuracy survey are used to measure repeatedly over specific period on survey markers what are designed and built based on IGS standard. The BERNESE 5.0 software is used to calculate received data over period based on IGS coordinates.

Applied results

• At the present and near future (10 years later), GPS is till the most popular GNSS system for civil purposes in Vietnam. However, we have to prepare carefully to get good effects by doing following programs: Build, standardize geography database that is the foundation to combine with GPS services for particular applied fields. Build GPS base stations covers Vietnam. International cooperation in GNSS technology for handing over the technic, data, and training.
• The proposed process is applied for Cam Pha cement factory. The results of construction subsidence monitoring by GPS technology are compared with the results gotten by high accuracy Total station method due to accuracy assessment for GPS monitoring.
• The results of monitoring the subsidence in Cam Pha cement factory show that: The applied process made sure the accuracy of monitoring in horizontal aspect as well as vertical aspect. The Cam Pha factory is moving following the West, however the wharf which extended to the Bai Tu Long bay more than 4km is rotating following the North West direction. On the vertical, Cam Pha factory is subsiding suitable with its foundation structure, farther the main land, the more substantial subsidence.  

• Propose to select the GPS will be used as the main system for GNSS purposes in Vietnam in near future.
• Build the completed process for monitoring coastal constructions subsidence by applying the high accuracy GPS technology.
• Determine the systematic movement of Cam Pha cement factory.

• Scientific papers in referred journals: 02
• Technological products:

1. Full report of the research
2. The process of application high accuracy GPS technology for monitoring coastal construction subsidence
3. Data of monitoring the subsidence of Cam Pha cement factory over 5 survey periods by GPS technology and Total station technology
4. Survey markers and their coordinates for continuing researches
5. Other products: Methodology and survey data was used for defending successfully a master thesis in the name Application of the high accuracy GPS technology to research the movement of Cam Pha cement factory. 

The research process can be applied for other constructions which is similar foundation characteristics to Cam Pha cement factory.