机载LiDAR点云密度对DEM精度的影响

doi:10.13474/j.cnki.11-2246.2022.0155

摘要/Abstract

摘要： 机载激光雷达技术(LiDAR)作为一项先进的遥感技术,是植被覆盖区DEM获取的重要手段之一,而不同地形坡度条件及点云密度对DEM产品质量有重要影响。本文以辽宁省某市的机载LiDAR数据为基础,选取5种不同地形坡度的点云数据,通过随机、等间距及基于曲率3种不同的点云抽稀方法,按照点云保留率为80%、60%、40%、20%和10%共5个不同梯度的抽稀倍数对原始点云进行抽稀简化处理,生成与之对应的DEM并对其进行精度评价,以此研究地形坡度、点云抽稀方法、抽稀倍数对DEM精度的影响。结果表明,DEM精度与地形坡度呈负相关关系,即RMSE随地形坡度升高不断增加;基于曲率的抽稀方法在地形坡度＞30°时,相较于其他两种方法RMSE较小,具有明显优势;40%的点云保留率是平衡DEM精度与数据存储效率的一个节点,当点云保留率<40%时,DEM的高程RMSE会迅速增大。该研究对于利用机载LiDAR进行大范围DEM生产具有一定的指导和借鉴意义。

关键词: 机载激光雷达, 数字高程模型, 点云密度, 精度, 点云抽稀

Abstract: As an advanced remote sensing technology, airborne LiDAR is one of the important means to obtain high-precision digital elevation models (DEM) of vegetation coverage area. Different terrain slope conditions and point cloud density have an important impact on the accuracy of DEM products. Based on airborne LiDAR point data from a city in Liaoning province, this paper selects the point cloud data with different terrain slopes from 0° to 50° and adopts three different point cloud thinning methods:random, equidistant and curvature. The original point cloud is thinned and simplified according to the thinning multiple of five different gradients with the point cloud retention rate of 80%,60%,40%,20% and 10%,and the corresponding DEM is generated and its accuracy is evaluated. Based on this, the influence of terrain gradient, point cloud thinning method and thinning multiple on DEM accuracy is studied. The results show that there is a negative correlation between DEM accuracy and terrain slope, that is the RMSE increases with the increase of terrain slope.Compared with the other two methods,the RMSE of curvature based thinning method is smaller when the terrain slope is greater than 30° and has obvious advantages.When the point cloud retention rate is less than 40%, the RMSE of DEM will increase rapidly.This research has certain guidance and reference significance for large-scale DEM production using airborne LiDAR.

Key words: airborne LiDAR, digital elevation model, point cloud density, accuracy, point cloud thinning

中图分类号:

P237

王道杰, 陈倍, 孙健辉. 机载LiDAR点云密度对DEM精度的影响[J]. 测绘通报, 2022, 0(5): 140-144,169.

WANG Daojie, CHEN Bei, SUN Jianhui. Study on the effects of point density on DEM accuracy of airborne LiDAR[J]. Bulletin of Surveying and Mapping, 2022, 0(5): 140-144,169.

参考文献

[1] 汤国安,李发源,刘学军.数字高程模型教程[M]. 3版.北京:科学出版社, 2016.
[2] 李德仁,丁霖,邵振峰.关于地理国情监测若干问题的思考[J].武汉大学学报(信息科学版),2016, 41(2):143-147.
[3] 李振洪,李鹏,丁咚,等.全球高分辨率数字高程模型研究进展与展望[J].武汉大学学报(信息科学版),2018, 43(12):1927-1942.
[4] TOMÁS R, LI Zhenhong. Earth observations for geohazards:present and future challenges[J]. Remote Sensing, 2017, 9(3):194.
[5] 程维明,周成虎,申元村,等.中国近40年来地貌学研究的回顾与展望[J].地理学报, 2017, 72(5):755-775.
[6] 汤国安,那嘉明,程维明.我国区域地貌数字地形分析研究进展[J].测绘学报, 2017, 46(10):1570-1591.
[7] 仝迟鸣,周成虎,程维明,等.基于DEM的黄土塬形态特征分析及发育阶段划分[J].地理科学进展, 2014,33(1):42-49.
[8] 杨昕,汤国安,袁宝印,等.黄土高原勺状沟壑特征及发育过程[J].地理研究, 2021, 40(7):1870-1886.
[9] KOU Pinglang, XU Qiang, YUNUS A P, et al. Multi-temporal UAV data for assessing rapid rill erosion in typical gully heads on the largest tableland of the Loess Plateau, China[J]. Bulletin of Engineering Geology and the Environment, 2020, 79(4):1861-1877.
[10] 田佳榕,代婷婷,徐雁南,等.基于地基激光雷达的采矿废弃地生态修复的植被参数提取[J].生态与农村环境学报, 2018, 34(8):686-691.
[11] XU Qiang, CHEN Wanlin, ZHAO Kuanyao, et al. Effects of land-use management on soil erosion:a case study in a typical watershed of the hilly and gully region on the Loess Plateau of China[J].CATENA,2021,206:105551.
[12] 杨辉山,雷丽珍.机载LiDAR点云获取与高精度DEM建设关键技术探讨[J].测绘通报, 2019(3):124-127.
[13] 胡翰,丁雨淋,朱庆,等.面向全球DEM生产的点云智能滤波与DEM泊松编辑方法[J].测绘学报, 2019, 48(3):374-383.
[14] 杜青松,李国玉,彭万林,等.利用InSAR技术获取高寒高海拔地区高精度DEM[J].测绘通报, 2021(3):44-49.
[15] 马洪超.激光雷达测量技术在地学中的若干应用[J].地球科学, 2011, 36(2):347-354.
[16] 马晓雪,吴中海,李家存. LiDAR技术在地质环境中的主要应用与展望[J].地质力学学报, 2016, 22(1):93-103.
[17] GÖRVM T. Landslide recognition and mapping in a mixed forest environment from airborne LiDAR data[J]. Engineering Geology, 2019, 258:105155.
[18] ROERING J J,MACKEY B H,MARSHALL J A,et al.'You are HERE':connecting the dots with airborne lidar for geomorphic fieldwork[J]. Geomorphology, 2013, 200:172-183.
[19] ANDERSON E S, THOMPSON J A, AUSTIN R E. LIDAR density and linear interpolator effects on elevation estimates[J]. International Journal of Remote Sensing, 2005, 26(18):3889-3900.
[20] LIU X,ZHANG Z,PETERSON J,et al.The effect of LiDAR data density on DEM accuracy[C]//Proceedings of 2007 International Congress on Modelling and Simulation.Christchurch:[s.n.],2007.
[21] JIA Yafei, LAN Tian, PENG Tao, et al. Effects of point density on DEM accuracy of airborne LiDAR[C]//Proceedings of 2013 IEEE International Geoscience and Remote Sensing Symposium-IGARSS. Melbourne:IEEE, 2013:493-496.
[22] 王康康,郑学东,赖旭东.机载LiDAR点云密度与DEM产品精度关系研究[J].测绘地理信息, 2021, 46(3):78-82.
[23] 杨明军,苏春梅,康冰锋,等.平原地区机载激光雷达数据的抽稀算法分析[J].测绘通报, 2019(1):101-107.