Design And Realization Of 3D Situation Display Based On Electronic Chart

With the progress of science and technology and the increasing demand of military and civilian affairs,the exploitation and utilization of Marine resources has become the focus of competition among countries.Navigation information is an important support and guarantee for the smooth completion of ship navigation and Marine development operations.The electronic chart can dynamically display the navigation information based on the chart background in real time and can assist the seafaring personnel to complete various tasks efficiently.However,the current electronic chart can only provide basic two-dimensional navigation information,for the three-dimensional seabed topography and Marine environment and other information can not be vividly described,still need seafaring personnel to manually process a lot of data received by various equipment.This not only fails to realize the effective analysis and grasp of the overall situation,but also reduces the efficiency of navigation operations.So how in two-dimensional electronic chart,on the basis of the implementation situation of information display at the same time this vessel submarine topography and the Marine environment,according to the three-dimensional information make the sailors use visual way to find out the rule and the hidden intrinsic phenomenon,better support navigation personnel to make decisions,many scholars have become the research focus.This paper mainly studies the design and implementation of three dimensional display system of submarine topography and Marine environment temperature field information based on electronic chart.Firstly,the development of electronic chart,offshore platform and software,and visualization of Marine environment data are reviewed.Aiming at the problems in the current practical application,the research problems and ideas of this paper are put forward.This paper briefly introduces the basic knowledge of electronic chart,including the basic concept of electronic chart and related coordinate system,classification of terrain visualization elevation model and 3d visualization method.Secondly,3d visualization of terrain is studied based on electronic chart data.The research mainly analyzes the realization process of 3d terrain model,including the acquisition of s-57 format electronic chart data and the grid establishment of elevation model,analyzes the interpolation method of elevation data model in detail,and proposes the adaptive improvement scheme on this basis,and designs the simulation verification.Thirdly,the ray projection algorithm is analyzed,aiming at the shortcoming of the low efficiency of resampling process caused by the traditional trilinear interpolation in the case of large amount of temperature field data,a method of determining the sampling point by using the property of spatial geometry and the vector extending outward is proposed to simplify the calculation.At the same time,a sampling method of variable step size is proposed for image synthesis to further optimize the sampling efficiency.Simulation experiment is designed to verify the improved algorithm.Finally,based on s-57 electronic chart data,the software of 3d visualization fusion display system of submarine topography and Marine environment temperature field is designed and implemented in VS2010 and Open GL development environments.The overall goal of the system is to realize the fusion display of the ship’s situation information,3d terrain information and ocean temperature field based on the electronic chart data.