几何特性与流线追踪相结合的地形结构线提取法
Geometry Characteristic and the Tracing of Flown Lines Combined to Extract Terrain Structure Lines
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摘要: 以距离变换为主要工具,建立了能追踪任意点流水线的数字地表流线模型。利用等高线几何特性分析法和DEM高程信息找出等高线上的山谷点,并以此作为起点进行流水线追踪,同时,用流线与等高线的交点是否符合山谷点的几何特性来决定流线追踪是否结束。这样,将山谷点的水总是顺谷而下的自然物理特性与山谷点所具有的几何特性紧密结合,得到山谷点的流线就是所求的山谷线。实验证明,该方法能有效地解决地形特征线段合理连接的问题,能控制结构线提取的详略程度。Abstract: A new method for automatic extraction of structure lines is developed by the new(idea) includes 3D physical analysis and 2D geometrical analysis.The new idea is based on the fact that the flown line whose start point is a valley point at upriver always flows along the lowest direction,and the flown line is also a valley line.A real contour map was used as testing data.As the result,the valley lines extracted automatically by this method can basically represent the topographic features of the corresponding topographical map.The new method takes advantages of 2D geometrical analysis and 3D terrain analysis and it is effective.
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