A New Organization and Indexing Method Of Multibeam Point Cloud Data In 3D Marine GIS

摘要

Multibeam sounding system can be used for the acquisition of high-precision digital seabed terrain model, it brings new opportunities for the development of 3D marine GIS (Geographic Information System). But its massive point cloud data poses great challenge for its storage and visualization. This paper proposes a new storage strategy and gives an optimized visualization method specifically for the storage strategy. First, we take advantage of the point cloud coordinate's regularity to sort these points according to certain rules and efficiently organize it through multiple spatial index. Vertically, a multi-level pyramid index is established. We generate a number of levels data with different level of detail and different scale, namely the static level of detail (LOD) model, in this way, a trade-off between appropriate redundant storage space and efficient data retrieve is achieved. Horizontally, for all levels of the pyramid model, we establish a tiled quadtree index, and generate a cache image for each tile. Secondly, an optimized visualization method in accordance with the storage strategy is also designed. Based on the current area of interest and data dispatch algorithm, we calculate the corresponding tile location and directly load the cache image to lessen the workload of complex spatial data operation, reduce the rendering burden of spatial data. We can generate customized dynamic cache with specific area of interest and scale, to improve the visual effect, too.