一种从高程格网中提取等高线的算法  

An algorithm for generating contour from gridded DEM

作　　者：王涛[1] 毋河海[2] 

机构地区：[1]中国测绘科学研究院,北京100039 [2]武汉大学资源与环境科学学院,武汉430079

出　　处：《测绘科学》2006年第2期108-110,共3页Science of Surveying and Mapping

基　　金：国家自然科学基金资助项目(40171079);地理工程信息工程国家测绘局实验室项目

摘　　要：对高程格网内插等高线的算法进行了优化,设计了新的遍历策略,使用两个变量控制内插的方向,在交叉网格处根据新的标准来决定下一步的走向,并且通过新的条件选择遍历开始的单元边,使得算法能够生成满足方向一致化要求的等高线。讨论了降低不规则等高线图形的方法。提出了进一步优化需要考虑的诸多因素。This paper designs a new algorithm for generating contour from Gridded DEM.Firstly we optimize the threading process by using two variables to control the direction of threading and give new criteria to handle the crossing cells.Secondly a novel strategy is proposed to select an appropriate starting grid cell for the threading.The strategy can ensure that all the generated contour are in the same direction,that is,each contour line's left area is higher than itself and right lower.In the third section,we discuss the exceptional cases when the grid cell's elevation is equal to the contour's elevation and the irregularities of the contour curve which is reduced by the smoothing process over the grid.

关 键 词：格网DEM 等高线 自动提取 算法 

分 类 号：P282[天文地球—地图制图学与地理信息工程] TP311[天文地球—测绘科学与技术]