适用于将离散点云数据（.txt），转换为IGS格式- This procedure will be suitable for is separated the cloud data (txt), the transformation will be the IGS form-applied to discrete point cloud data (. Txt). Converting to IGS format - This procedure will be suitable for i s

针对.las或者.txt的点云数据进行处理，按照最小高程值构建地面点格网，最终完成DEM的构建。