中文摘要：

从在空中的激光扫描获得的点云的赤裸的地球上的点的抽取是为数字地面模型(DTM ) 的产生的最重要的步骤之一。这个过程被称为“过滤”。然而，大多数当前的过滤器侵蚀在陡峭的倾斜的风景并且在断绝的赤裸的地球，并且他们保留低植被。因此，为提取地面的一个新过滤方法基于距离限制指在这篇论文被建议。角度标准被用来保证算法的坚韧性。试验性的结果证明建议过滤方法罐头有效地在复杂城市的区域从点云导出扎根的点。

英文摘要：

The extraction of points on the bare earth from point clouds acquired by airborne laser scanning is one of the most important steps for the generation of digital terrain models （DTM）. This process is called ＂filtering＂. However, most of the cur- rent filters erode the bare earth in steep sloped landscapes and at discontinuities, and they retain low vegetation. Therefore, a new filtering method for extracting ground points based on a distance limit is proposed in this paper. The angle criterion is used to assure the robustness of the algorithm. The experimental results show that the proposed filtering method can effectively derive the ground points from point clouds in complex urban areas.