Research On The Surveying Techniques Of Seashore Islands And Reefs Based On GNSS And Geophysical Methods

With the rising strategy status of the maritime, Island reefs are the the base station. Island topographic survey and getting the geology data accurately are the basis of the’digital ocean’. Some basic measurement tasks of sea reefs coming to an end, to make the map integration and expression of sea reefs and land come true. Height datum transfer among island reefs and building a seamless vertical datum transformation model could be the problems to solve.Tidal reefs due to restrictions by environmental conditions such as survey, a comprehensive survey and mapping tools proven in a limited time, to identify seabed geological structures, geotechnical data provide the basis for the structures on the offshore reefs. In this thesis, the research base on offshore reefs survey and verify the method of vertical datum transformation by experiment. And integrated geophysical techniques are used in geological tectonic survey. The experiment get the principle of the island reefs stratify and the detection result.The content of this thesis mainly has the following several aspects:Firstly, elaborate the related technology and theory of the island topographic survey, Demonstrates the theoretical basis of the GNSS and the geoid refinement techniques apply to the height datum transformation and a seamless vertical datum transformation model, and it’s feasibility and practicality.Secondly, introduce the Geophysical principles and techniques suitable for shallow and marine. The idea of using integrated geophysical techniques which combine the GNSS to survey the seabed is proposed.Finally, Theory and technical methods were validated in the island reefs experiment. The research can be the reference of some similar projects.The results of the paper can solve some problems of the vertical datum transfer in island surveying projects, the feasibility of the method and the reliability of the results are demonstrated in the experiment. The method can be effectively applied in the islands which lack of gravity data.And it has a certain practical value and significance of generalization.