Three-dimensional Modeling And Visualization Based On S-57 Standard Chart Data And NASA Data

The oceans cover about 70%of the earth's surface and are rich in resources.Coastal zones,islands and reefs in the ocean occupy a special position in the United Nations convention on the law of the sea.The environment around islands and coastal zones is important and complex.Three-dimensional modeling can promote the development of "digital ocean" and provide a training environment for the laboratory submarine simulator to simulate the sea area.Because of the rapid development of computer technology and the continuous improvement and perfection of computer graphics and other technologies,it is possible to visualize the three-dimensional terrain of coastal zone.In this paper,we use two-dimensional vector information of electronic chart to construct three-dimensional ocean topography,and combine it with NASA data to construct coastal zone model,and display it in three-dimensional.In this paper,combined with electronic chart and geographic information system,the three-dimensional terrain of training sea area is modeled.OpenGL is used to realize three-dimensional visualization,which has a strong sense of reality.This research method is applied to the navigation simulator of the Navigation Simulation Dynamic Laboratory of Dalian Maritime University.(1)based on s-57 standard electronic chart data,data such as water depth point,coastline and isobaric line are extracted for distribution and management,and improved growth network algorithm is proposed to construct digital elevation model by using the extracted water depth point data.(2)singularity processing of NASA data,interception of NASA data using shoreline chart data,and three-dimensional visualization of NASA data.(3)the datum of NASA data and s-57 standard chart data was unified,and several inconsistencies of land and ocean multi-source data were studied in depth.Based on the unified plane datum,vertical datum,data structure and expression model of the two data,the 3d modeling and visual expression of the coastal zone and surrounding terrain are carried out to eliminate the differences between them.(4)OpenGL three-dimensional rendering engine is used to render and visualize terrain,add texture and illumination to improve the accuracy and reality of navigation simulator three-dimensional scene,which has strong practical application value.