An improved plane fitting based filtering algorithm for airborne lidar data

Due to the strengths and weaknesses of the existing filtering methods, an improved plane fitting algorithm is presented for filtering of airborne LIDAR data in the paper. Firstly, resampled LIDAR data were segmented using region growing method, and the largest connected region was selected as the initial ground area. Secondly, non-ground points in the initial ground area were removed by a slope threshold, which is suitable for the study area. Finally, the ground points were interpolated using Kriging method and the filtering results were gained. The dataset provided by International Society for Photogrammetry and Remote Sensing (ISPRS) was selected as the test data. The influences of different slope thresholds on the filtering results were given after filtering experiments. The result shows that the optimal slope threshold in this area was 0.5 and the overall error rate was only 4.29%. Contrast to the traditional filtering method based on plane fitting, the proposed method is more simple and practical.