对基于DEM数据库的可视域分析，该算法在时间复杂度较低的情况下大大减少了访问数据库的次数，取得了很好的效果。

For viewshed analysis based on DEM database, the algorithm having a good experimental effect reduces obviously the frequency of access to database with lower time complexity.

youdao

对基于DEM数据库的可视域分析，该算法在时间复杂度较低的情况下大大减少了访问数据库的次数，取得了很好的效果。

For viewshed analysis based on DEM database, the algorithm having a good experimental effect reduces obviously the frequency of access to database with lower time complexity.

youdao