长江中下游河道岸滩低空机载LiDAR点云地形滤波算法
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摘要
探索新兴的低空机载Li DAR技术,解决长江中下游植被高覆盖、高遮挡区岸滩地形测绘难题。提出一种针对多层次、高密度植被覆盖区的低空机载Li DAR点云植被滤波算法,该算法通过多回波分析对点云进行粗滤波后,采用数学形态学运算获取地面种子点,对地形局部进行趋势面拟合,再通过随机采样一致性检测,剔除植被点,保留地面点,从而获取测区的数字高程模型(DEM)。典型测区试验表明,该滤波算法能解决长江中下游河道岸滩地区地形起伏较大、植被高覆盖区域植被点云智能化剥离难题。根据测区实际情况,设计针对性的滤波算法,即使是植被与地面点云高度混淆、激光穿透率低于15%的复杂情形,仍能有效分离出地面和非地面点。
This paper firstly explores and applies the newly low-altitude airborne Li DAR technology to solve the mapping problem of the middle-lower Yangtze River Riparian zone covered with multi-layer and high-density vegetation. A vegetation filtering algorithm is proposed for the low-attitude airborne Li DAR point clouds collected in the complex area with multi level and dense vegetation coverage. After the coarse filtering of point clouds by multiecho analysis,this algorithm extracts the ground seed points by morphological calculation,fits the trend surface of the local terrain,then eliminates the vegetation points and preserves the ground points using the Random Sample Consensus,thereby acquiring the DEM of measured area. The experimental results show that the proposed algorithm can intelligently remove the vegetation point clouds in the middle-lower Yangtze River riparian zone,where topographic relief is large and vegetation cover is dense. This research also shows that by designing a special filtering approach,it is possible to classify laser points into terrain and vegetation automatically even for thoroughly mixed vegetation and terrain points with low penetration rate of below 15%.
This paper firstly explores and applies the newly low-altitude airborne Li DAR technology to solve the mapping problem of the middle-lower Yangtze River Riparian zone covered with multi-layer and high-density vegetation. A vegetation filtering algorithm is proposed for the low-attitude airborne Li DAR point clouds collected in the complex area with multi level and dense vegetation coverage. After the coarse filtering of point clouds by multiecho analysis,this algorithm extracts the ground seed points by morphological calculation,fits the trend surface of the local terrain,then eliminates the vegetation points and preserves the ground points using the Random Sample Consensus,thereby acquiring the DEM of measured area. The experimental results show that the proposed algorithm can intelligently remove the vegetation point clouds in the middle-lower Yangtze River riparian zone,where topographic relief is large and vegetation cover is dense. This research also shows that by designing a special filtering approach,it is possible to classify laser points into terrain and vegetation automatically even for thoroughly mixed vegetation and terrain points with low penetration rate of below 15%.
引文
[1]丁贤荣,王文,杨涛,等.河道数字地形信息系统与长江镇扬河段GIS研制[J].河海大学学报(自然科学版),2001,29(4):116-119.(DING Xianrong,WANG Wen,YANG Tao,et al.River digital terrain information system and GIS for Zhengyang section of Yangtze River[J].Journal of Hohai University(Natural Sciences),2001,29(4):116-119.(in Chinese))
[2] SHAN J,APARAJITHAN S. Urban DEM generation from raw Li DAR data[J]. Photogrammetric Engineering and Remote Sensing,2005,71(2):217-226.
[3]POLAT N,UYSAL M. Investigating performance of airborne Li DAR data filtering algorithms for DTM generation[J].Measurement,2015,63:61-68.
[4] BLASZCZAK-BAK W,JANOWSKI A,KAMINSKI M,et al. Application of the M-split method for filtering airborne laser scanning data-sets to estimate digital terrain models[J].International Journal of Remote Sensing,2015,36(9):2421-2437.
[5]AXELSSON P. DEM generation from laser scanner data using adaptive TIN models[J]. International Archives of Photogrammetry and Remote Sensing,2000,33(B4/1):111-118.
[6]ZHANG Keqi,CHEN Shuching,WHITMAN D. A progressive morphological filter for removing nonground measurements from airborne Li DAR data[J]. IEEE Transactions on Geoscience and Remote Sensing,2003,41(4):872-882.
[7]ZHANG Keqi,WHITMAN D. Comparison of three algorithms for filtering airborne lidar data[J]. Photogrammetric Engineering and Remote Sensing,2005,71(3):313-324.
[8]SU Wei,SUN Zhongping,ZHONG Ruofei,et al. A new hierarchical moving curve-fitting algorithm for filtering lidar data for automatic DTM generation[J]. International Journal of Remote Sensing,2015,36(14):3616-3635.
[9]王明华,张小红,曾涛.机载Li DAR数据滤波预处理方法研究[J].武汉大学学报(信息科学版),2010,35(2):224-227.(WANG Minghua,ZHANG Xiaohong,ZENG Tao. Preprocessing algorithms for filtering airborne Li DAR data[J].Geomatics and Information Science of Wuhan University,2010,35(2):224-227.(in Chinese)).
[10]VOSSELMAN G. Slope based filtering of laser altimetry data[J]. International Archives of Photogrammetry and Remote Sensing,2000,33(B3/2):935-942.
[11]UYSAL M,POLAT N. Investigating performance of airborne Li DAR data filtering with triangular irregular network(TIN)algorithm[J]. The International Archives of Photogrammetry(Remote Sensing and Spatial Information Sciences),2014,40(7):199-202.
[12]MENG Xuelian,CURRIT Nate,ZHAO Kaiguang. Ground filtering algorithms for airborne Li DAR data:a review of critical issues[J]. Remote Sensing,2010,2(3):833-860.
[13] FRANCESCO P,ALBERTO G,ANTONIO V. Ground filtering and vegetation mapping using multi-return terrestrial laser scanning[J]. ISPRS Journal of Photogrammetry and Remote Sensing,2013,76(2):56-63.
[14]WALLACE L,LUCIEER A,WATSON C,et al. Development of a UAV-LiDAR system with application to forest inventory[J].Remote Sensing,2012,4(6):1519-1543.
[15]GEORGE S,GEORGE V. Experimental comparison of filter algorithms for bare-earth extraction from airborne laser scanning point clouds[J]. ISPRS Journal of Photogrammetry and Remote Sensing,2004,59(12):85-101.
[16]黄先锋,李卉,王潇.机载Li DAR数据滤波方法评述[J].测绘学报,2009,38(5):465-469.(HUANG Xianfeng,LI Hui,WANG Xiao. Filter algorithms of airborne Li DAR data:review and prospects[J].Acta Geodaetica et Cartographica Sinica,2009,38(5):465-469.(in Chinese))
[2] SHAN J,APARAJITHAN S. Urban DEM generation from raw Li DAR data[J]. Photogrammetric Engineering and Remote Sensing,2005,71(2):217-226.
[3]POLAT N,UYSAL M. Investigating performance of airborne Li DAR data filtering algorithms for DTM generation[J].Measurement,2015,63:61-68.
[4] BLASZCZAK-BAK W,JANOWSKI A,KAMINSKI M,et al. Application of the M-split method for filtering airborne laser scanning data-sets to estimate digital terrain models[J].International Journal of Remote Sensing,2015,36(9):2421-2437.
[5]AXELSSON P. DEM generation from laser scanner data using adaptive TIN models[J]. International Archives of Photogrammetry and Remote Sensing,2000,33(B4/1):111-118.
[6]ZHANG Keqi,CHEN Shuching,WHITMAN D. A progressive morphological filter for removing nonground measurements from airborne Li DAR data[J]. IEEE Transactions on Geoscience and Remote Sensing,2003,41(4):872-882.
[7]ZHANG Keqi,WHITMAN D. Comparison of three algorithms for filtering airborne lidar data[J]. Photogrammetric Engineering and Remote Sensing,2005,71(3):313-324.
[8]SU Wei,SUN Zhongping,ZHONG Ruofei,et al. A new hierarchical moving curve-fitting algorithm for filtering lidar data for automatic DTM generation[J]. International Journal of Remote Sensing,2015,36(14):3616-3635.
[9]王明华,张小红,曾涛.机载Li DAR数据滤波预处理方法研究[J].武汉大学学报(信息科学版),2010,35(2):224-227.(WANG Minghua,ZHANG Xiaohong,ZENG Tao. Preprocessing algorithms for filtering airborne Li DAR data[J].Geomatics and Information Science of Wuhan University,2010,35(2):224-227.(in Chinese)).
[10]VOSSELMAN G. Slope based filtering of laser altimetry data[J]. International Archives of Photogrammetry and Remote Sensing,2000,33(B3/2):935-942.
[11]UYSAL M,POLAT N. Investigating performance of airborne Li DAR data filtering with triangular irregular network(TIN)algorithm[J]. The International Archives of Photogrammetry(Remote Sensing and Spatial Information Sciences),2014,40(7):199-202.
[12]MENG Xuelian,CURRIT Nate,ZHAO Kaiguang. Ground filtering algorithms for airborne Li DAR data:a review of critical issues[J]. Remote Sensing,2010,2(3):833-860.
[13] FRANCESCO P,ALBERTO G,ANTONIO V. Ground filtering and vegetation mapping using multi-return terrestrial laser scanning[J]. ISPRS Journal of Photogrammetry and Remote Sensing,2013,76(2):56-63.
[14]WALLACE L,LUCIEER A,WATSON C,et al. Development of a UAV-LiDAR system with application to forest inventory[J].Remote Sensing,2012,4(6):1519-1543.
[15]GEORGE S,GEORGE V. Experimental comparison of filter algorithms for bare-earth extraction from airborne laser scanning point clouds[J]. ISPRS Journal of Photogrammetry and Remote Sensing,2004,59(12):85-101.
[16]黄先锋,李卉,王潇.机载Li DAR数据滤波方法评述[J].测绘学报,2009,38(5):465-469.(HUANG Xianfeng,LI Hui,WANG Xiao. Filter algorithms of airborne Li DAR data:review and prospects[J].Acta Geodaetica et Cartographica Sinica,2009,38(5):465-469.(in Chinese))