Research And Implementation On Forestry Resource Data Fusion Based On 3D Terrain

Though there are numerous forest resources data, in a way, one kind of forest resources data can only reflect a certain characteristic of the object due to the existing different means and methods being used to obtain forest resources data.Therefore, the data fusion to forest resources multi-source data is very important to gain complete and accurate information.By using the MapX and OpenGL tools and taking the Zhejiang province Lin'an city as experiments region, this research not only built a three-dimensional terrain model, but also studied and implemented the forest resources heterogeneous data fusion. In this paper, the results achieved mainly in the following aspects:1. Detailedly analyzed the composition, sources and characteristics of forest resources data. It was the foundation for data fusion and integration.2. Proposed and implemented the integration and the establishment of the forest resources data fusion method based on the three-dimensional terrain model. In this paper, it used the Grid model to build the three-dimensional terrain model, took the DEM elevation data as quadrilateral's apex elevation data, then, after the set up of a reasonable light parameter and vector calculating method, a quadrilateral was constructed by using OpenGL. The approximation of the successive quadrilateral would generate the up and down 3D terrain which achieved a realistic vision of the forest resources data.3. Fused the remote sensing data by 3D terrain texture mapping mechanism. Considering the characteristics of forest resource data, the two-dimensional map was established by MapInfo, and three-dimensional window was constructed by OpenGL.Through the Gauss projection coordinates formula and anti-count formula, it realized the mutual conversion of the two-dimensional window geodetic coordinates (L , B) and three-dimensional coordinates of the window Gaussian plane (X, Y), then achieved the organic link between the two-dimensional and three-dimensional topographical map.4. Accessed to 3D attribute data. It obtained town boundary, village boundary and sub-compartment boundary characteristics by accessing to 2D maps used MapX components. Through two-dimensional and three-dimensional topographical map coordinates conversion mechanism, it converted all of the feature points and achieved the reasonable conversion method from two-dimensional map attribute data to 3D data.5. Effectively achieved the forest resources data fusion. Firstly, it converged different kinds of the three-dimensional topographical basis data including town boundary, village boundary and subcompartment boundary data. Secondly, it fused fire teams, forest fire prevention materials, and other fire data. Then, it implemented its two-dimensional and three-dimensional visualization.Meanwhile, it's modify, delete and query operation functions were provided. Finally, it also integrated GPS data and realized the review of the GPS track that provided the foundation for the calculation of the following fire site area.