插值是数字高程模型的核心分析方法,也是构建数字高程模型的常用手段.面对海量的离散点云数据,插值生成DEM的过程需消耗大量的时间,将并行计算运用到插值计算中会显著缩短计算时间.结合点云数据分布不均匀的特点,本文提出了一套针对离散点云并行插值生成格网DEM的数据划分方法,将读取、搜索邻域、插值计算、输出4个过程的处理时间量化,保证划分后形成的子块处理时间均衡,提高了并行计算效率.
Interpolation is the core analysis method of the digital elevation model,which is also a common means of the con- struction of the digital elevation model. It consumes a lot of time to generate an interpolated DEM when discrete point cloud data is magnitude. Applied parallel computing to interpolation calculation can significantly shorten the calculation time. Taking the point cloud data distribution characteristics into consideration,this paper raises a data partition method, which is used for parallel interpolation of discrete cloud points to generate grid DEM. This approach quantifies the processing time of four procedures, such as input, searching neighborhood, interpolation calculation and output. This method can keep the balance of the processing time of the sub-blocks thereby improving the efficiency of parallel interpolation.