机载激光雷达测量系统误差检校方法研究
摘要
机载激光雷达测量技术是将全球定位技术、惯性导航技术以及激光扫描测距技术有效集成,具有受天气影响小、自动化程度高、成图周期短等特点。目前国内许多家研究单位和公司已经引进了国外高性能的机载小光斑激光雷达系统,但这种引进模式存在明显的弊端,如价格昂贵、软件算法保密等问题,因此研制具有自主知识产权的高精度机载激光雷达测量系统迫在眉睫。然而目前,不论国际还是国内在激光雷达测量技术上都迫切需要解决的问题是消除系统误差的影响。基于此,本文开展了机载激光雷达测量系统误差检校方法的研究。
机载激光雷达测量系统在对地定位过程中受到来自激光扫描仪的测距、测角误差,POS (Position and Orientation System)的姿态和位置测量误差,系统集成误差等各种因素的影响。本文分析了机载激光雷达测量系统各组成部分的工作原理以及机载激光雷达测量系统所涉及的坐标系统及其测量原理,详细讨论了机载激光雷达测量系统中的各种误差源,以国产轻小型机载激光雷达测量系统为基础,重点阐述了激光扫描仪检校、IMU(Inertial Measurement Unit)标定以及基于地面模拟飞行试验场的系统安置角误差检校的方法。本文的具体内容包括以下几个方面：
(1)分析了机载激光雷达测量系统对地测量原理,归纳并总结了目前主要的商业化机载激光雷达测量系统及其技术指标,比较了机载激光雷达与摄影测量、机载InSAR技术的异同点
(2)对机载激光雷达测量系统的误差源进行了汇总,分析了国内外在系统误差检校方面的研究现状,指出了目前主流的系统误差检校方法；
(3)探讨了激光扫描仪的单机检校方案,主要包括激光扫描仪的测距和测角误差检校方案,检校后的激光扫描仪测距和测角精度分别为3cm和1%度；
(4)研究了IMU精度的标定方法,主要完成了三项指标的标定：初始对准精度、静态漂移精度和动态跟踪精度的标定
(5)建立了基于地面模拟飞行试验场的机载激光雷达测量系统安置角误差检校模型,通过已知坐标的地而标志点精确反求系统安置角,最终得到在航高50m情况下的激光脚点三维坐标中误差均在2cm以内。
The airborne LiDAR (Light Detection And Ranging) is an earth observation technology of representing an available collection of laser scanning technology, global positioning technology, and inertial navigation technology. The airborne LiDAR has many characteristics, such as less impacted from weather, high automation degree and shorter mapping cycle. At present many domestic research institutes and companies have introduced high-performance airborne LiDAR systems with small footprint from foreign counties. However, this import model has its disadvantages of high price and secret software algorithms. Thus it urgently needs to develop high accuracy airborne LiDAR system with our own intellectual property rights. However, no metter international or domestic LiDAR technology needs to eliminate systematic errors instantly, which is the key point this paper discusses.
The performance of airborne LiDAR is affected from several factors, such as laser scanner's range and angle measurement errors, POS' position and orientation measurement errors and system integration errors and so on. The working principle of each part of airborne LiDAR system, the coordinate systems related to LiDAR system and its surveying principle are analyzed in this paper. Based on the domestic light-small airborne LiDAR system, this paper particularly studies the error sources of the airborne LiDAR system, states the error correction methods of laser scanner's range and angle measurements, IMU's measurements, and the systematic mounting-angle calibration method based on ground test field of flight simulation with relevant error correction models. The specific contents of this paper are as follows:
1. The airborne LiDAR system surveying principle, several international typical commercial airborne LiDAR systems and comparation with photogremmetry and airborne InSAR will be presented in this paper;
2. The analysis of airborne LiDAR system error sources, present situation and dominant methods of error calibration research;
3. The discussion of laser scanner calibration, which includes range and angle detecting error calibration, with range accuracy of 3cm and angle of 1% degree after calibration;
4. Accuracy determination method of IMU will be mentioned in this paper. It consists of three accuracies:initial alignment accuracy, static drift accuracy and dynamic trial accuracy;
5. Based on ground test field of flight simulation and relevant error correction models, the systematic parameters of mounting angles are calculated.3D coordinates RMS of laser points are in 2cm with 50m flight height.
机载激光雷达测量系统在对地定位过程中受到来自激光扫描仪的测距、测角误差,POS (Position and Orientation System)的姿态和位置测量误差,系统集成误差等各种因素的影响。本文分析了机载激光雷达测量系统各组成部分的工作原理以及机载激光雷达测量系统所涉及的坐标系统及其测量原理,详细讨论了机载激光雷达测量系统中的各种误差源,以国产轻小型机载激光雷达测量系统为基础,重点阐述了激光扫描仪检校、IMU(Inertial Measurement Unit)标定以及基于地面模拟飞行试验场的系统安置角误差检校的方法。本文的具体内容包括以下几个方面：
(1)分析了机载激光雷达测量系统对地测量原理,归纳并总结了目前主要的商业化机载激光雷达测量系统及其技术指标,比较了机载激光雷达与摄影测量、机载InSAR技术的异同点
(2)对机载激光雷达测量系统的误差源进行了汇总,分析了国内外在系统误差检校方面的研究现状,指出了目前主流的系统误差检校方法；
(3)探讨了激光扫描仪的单机检校方案,主要包括激光扫描仪的测距和测角误差检校方案,检校后的激光扫描仪测距和测角精度分别为3cm和1%度；
(4)研究了IMU精度的标定方法,主要完成了三项指标的标定：初始对准精度、静态漂移精度和动态跟踪精度的标定
(5)建立了基于地面模拟飞行试验场的机载激光雷达测量系统安置角误差检校模型,通过已知坐标的地而标志点精确反求系统安置角,最终得到在航高50m情况下的激光脚点三维坐标中误差均在2cm以内。
The airborne LiDAR (Light Detection And Ranging) is an earth observation technology of representing an available collection of laser scanning technology, global positioning technology, and inertial navigation technology. The airborne LiDAR has many characteristics, such as less impacted from weather, high automation degree and shorter mapping cycle. At present many domestic research institutes and companies have introduced high-performance airborne LiDAR systems with small footprint from foreign counties. However, this import model has its disadvantages of high price and secret software algorithms. Thus it urgently needs to develop high accuracy airborne LiDAR system with our own intellectual property rights. However, no metter international or domestic LiDAR technology needs to eliminate systematic errors instantly, which is the key point this paper discusses.
The performance of airborne LiDAR is affected from several factors, such as laser scanner's range and angle measurement errors, POS' position and orientation measurement errors and system integration errors and so on. The working principle of each part of airborne LiDAR system, the coordinate systems related to LiDAR system and its surveying principle are analyzed in this paper. Based on the domestic light-small airborne LiDAR system, this paper particularly studies the error sources of the airborne LiDAR system, states the error correction methods of laser scanner's range and angle measurements, IMU's measurements, and the systematic mounting-angle calibration method based on ground test field of flight simulation with relevant error correction models. The specific contents of this paper are as follows:
1. The airborne LiDAR system surveying principle, several international typical commercial airborne LiDAR systems and comparation with photogremmetry and airborne InSAR will be presented in this paper;
2. The analysis of airborne LiDAR system error sources, present situation and dominant methods of error calibration research;
3. The discussion of laser scanner calibration, which includes range and angle detecting error calibration, with range accuracy of 3cm and angle of 1% degree after calibration;
4. Accuracy determination method of IMU will be mentioned in this paper. It consists of three accuracies:initial alignment accuracy, static drift accuracy and dynamic trial accuracy;
5. Based on ground test field of flight simulation and relevant error correction models, the systematic parameters of mounting angles are calculated.3D coordinates RMS of laser points are in 2cm with 50m flight height.
引文
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4. Baltsavias E. Airborne laser scanning:basic relations and formulas[J]. ISPRS Journal of Photogrammetry and Remote Sensing,1999,54(2-3):199-214
5. Behan A. Quality Improvement of Scanning Laser Altimeter Data[EB/OL]. www.geo.tudelft.nl/frs/staff/avrilindex.html
6. Burman H. Adjustment of Laser Scanner Data for Correction of Orientation Errors[J]. International Archives of Photogrammetry and Remote Sensing, Vol.ⅩⅩⅩⅢ, Part B3:125-132
7. Chasmer L, C Hopkinson, B Smith, P Treitz. Examining the Influence of Changing Laser Pulse Repetition Frequencies on Conifer Forest Canopy Returns[J]. Photogrammetric Engineering & Remote Sensing,2006:1359—1367
8. Csanyi N, Toth C. Improvement of lidar data accuracy using lidar-specific ground targets[J]. Photogrammetric Engineering & Remote Sensing,2007,73(4):385-396
9. Favey E. Investigation and Improvement of Airborne Laser Scanning Technique for Monitoring Surface Elevation Changes of Glaciers[D]. ETH, Zurich:Technische wissensch aften,2001
10. Filin S. Recovery of systematic biases in laser altimetry data using natural surfaces[J]. Photogrammetric Engineering and Remote Sensing,2003,69(11):1235-1242
11. Filin S, Vosselman G. Adjustment of airborne laser altimetry strips[C]. International Archives of Photogrammetry and Remote Sensing,2004. ⅩⅩⅩⅤ, B3, Istanbul, Turkey
12. Habib A F, A P Kersting, Z Ruifang, M Al-Durgham, C Kim, D C Lee. LiDAR strip adjustment using conjugate linear features in overlapping strips[J]. International Archives of Photogrammetry and Remote Sensing,2008,37 (part B1):385—390
13. Jan Skaloud, Derek Lichti. Rigorous approach to bore-sight self-calibration in airborne laser scanning[J]. ISPRS Journal of Photogrammetry & Remote Sensing,2006(61):47-59
14. Kager H. Discrepancies between overlapping laser scanning strips—simultaneous fitting of aerial laser scanner strips[C]. International Archives of Photogrammetry and Remote Sensing,2004, ⅩⅩⅩⅤ, B/1 555-560
15. Kraus K, N P feifer. Determination of terrain models in wooded areas with airborne laser scanner data[J]. ISPRS Journal of Photogrammetry & Remote sensing,1998,53:193-203
16. Optech,2004. ALTM 30/70/100 User Manual, Toronto, Canada
17. Schenk T,2001. Modeling and analyzing systematic errors of airborne laser scanners[R]. Technical Notes in Photogrammetry No.19, Department of Civil and Environmental Engineering and Geodetic Science, The Ohio State University
18. Soininen A, Burman H,2005. TerraMatch for MicroStation. Terrasolid Ltd, Finland.
19. Vosselman G. Strip Offset Estimation Using Linear Features[EB/OL]. http: //www.Itc.nl/personal/vosselman/papers/vosselman2002. Columbus. pdf,2004
20. Vosselman G, Maas H G,2001. Adjustment and filtering of raw laser altimetry data[C]. Proceedings of OEEPEWorkshop on Airborne Laser scanning and Interferometric SAR for Detailed Digital Terrain Models, Stockholm, Sweden
21. Wehr A, Lohr U. Airborne Laser Scanning-an Introduction and Overview[J]. ISPRS, 1999,54(2/3):68-82
22. www.flimap.com
23. www.leica-geosystems.com
24. www.optech.ca
25. www.riegl.com
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27.戴永江.激光雷达原理[M].北京：国防工业出版社,2002：3—20
28.黄谟涛,翟国君,谢锡君等.多波束和机载激光测深位置归算及载体姿态影响研究[J].测绘学报,2000,29(1)：82—89
29.贾广帅.机载激光雷达系统数据特点和滤波方法研究[D].青岛：山东科技大学,2007
30.赖旭东,万幼川.机载激光雷达距离图像的边缘检测研究[J].红外与激光工程,2005
31.李德仁.摄影测量与遥感的现状及发展趋势[J].武汉测绘科技大学学报,2000,25(1)：1—6
32.李清泉,李必军,陈静.激光雷达测量技术及其应用研究[J].武汉测绘科技大学学报,2000,25(5)：387—392
33.李树楷,薛永琪.高效三维遥感集成技术系统[M].北京：科学出版社,2000
34.李松.星载激光测高仪发展现状综述[J].光学与光电技术,2004,2(6)： 4—6
35.李学友.IMU/DGPS辅助航空摄影测量原理、方法及实践[D].解放军信息工程大学博士学位论文,2005
36.李学友.IMU/DGPS (?)辅助航空摄影测量综述[J].测绘科学,2005：110—113
37.刘经南,张小红.激光扫描测高技术的发展与现状[J].武汉大学学报·信息科学版,2003,28(2)：132—137
38.刘经南,张小红,李征航.影响机载激光扫描测高精度的系统误差分析[J].武汉大学学报·信息科学版,2002,27(2)：111—117
39.刘沛.多源数据辅助机载LIDAR数据处理的关键技术研究[D].北京：中国测绘科学研究院,2008
40.刘艳丰.基于kd-tree的点云数据空间管理理论与方法[D]. 长沙：中南大学2009
41.罗伊萍.LIDAR数据滤波和影像辅助提取建筑物[D].郑州：中国人民解放军信息工程大学,2010
42.吕献林.多源数据辅助机载LiDAR数据生成DEM方法研究[D].武汉：中国地质大学,2009
43.马剑.机载LiDAR数据插值方法研究[D].焦作：河南理工大学,2010
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55.张志友.基于LIDAR数据和航空影像的地形与建筑物提取及三维可视化[D].北京：北京交通大学,2008
2. Abdullatif Alharthy. Airborne Laser Scanning:System Evaluation and Building Extraction[D]. Purdue University Doctor Thesis,2003
3. Baltsavias E. Airborne laser scanning:existing systems and firms and other resources[J]. ISPRS Journal of Photogrammetry and Remote Sensing,1999,54(2-3): 164-198
4. Baltsavias E. Airborne laser scanning:basic relations and formulas[J]. ISPRS Journal of Photogrammetry and Remote Sensing,1999,54(2-3):199-214
5. Behan A. Quality Improvement of Scanning Laser Altimeter Data[EB/OL]. www.geo.tudelft.nl/frs/staff/avrilindex.html
6. Burman H. Adjustment of Laser Scanner Data for Correction of Orientation Errors[J]. International Archives of Photogrammetry and Remote Sensing, Vol.ⅩⅩⅩⅢ, Part B3:125-132
7. Chasmer L, C Hopkinson, B Smith, P Treitz. Examining the Influence of Changing Laser Pulse Repetition Frequencies on Conifer Forest Canopy Returns[J]. Photogrammetric Engineering & Remote Sensing,2006:1359—1367
8. Csanyi N, Toth C. Improvement of lidar data accuracy using lidar-specific ground targets[J]. Photogrammetric Engineering & Remote Sensing,2007,73(4):385-396
9. Favey E. Investigation and Improvement of Airborne Laser Scanning Technique for Monitoring Surface Elevation Changes of Glaciers[D]. ETH, Zurich:Technische wissensch aften,2001
10. Filin S. Recovery of systematic biases in laser altimetry data using natural surfaces[J]. Photogrammetric Engineering and Remote Sensing,2003,69(11):1235-1242
11. Filin S, Vosselman G. Adjustment of airborne laser altimetry strips[C]. International Archives of Photogrammetry and Remote Sensing,2004. ⅩⅩⅩⅤ, B3, Istanbul, Turkey
12. Habib A F, A P Kersting, Z Ruifang, M Al-Durgham, C Kim, D C Lee. LiDAR strip adjustment using conjugate linear features in overlapping strips[J]. International Archives of Photogrammetry and Remote Sensing,2008,37 (part B1):385—390
13. Jan Skaloud, Derek Lichti. Rigorous approach to bore-sight self-calibration in airborne laser scanning[J]. ISPRS Journal of Photogrammetry & Remote Sensing,2006(61):47-59
14. Kager H. Discrepancies between overlapping laser scanning strips—simultaneous fitting of aerial laser scanner strips[C]. International Archives of Photogrammetry and Remote Sensing,2004, ⅩⅩⅩⅤ, B/1 555-560
15. Kraus K, N P feifer. Determination of terrain models in wooded areas with airborne laser scanner data[J]. ISPRS Journal of Photogrammetry & Remote sensing,1998,53:193-203
16. Optech,2004. ALTM 30/70/100 User Manual, Toronto, Canada
17. Schenk T,2001. Modeling and analyzing systematic errors of airborne laser scanners[R]. Technical Notes in Photogrammetry No.19, Department of Civil and Environmental Engineering and Geodetic Science, The Ohio State University
18. Soininen A, Burman H,2005. TerraMatch for MicroStation. Terrasolid Ltd, Finland.
19. Vosselman G. Strip Offset Estimation Using Linear Features[EB/OL]. http: //www.Itc.nl/personal/vosselman/papers/vosselman2002. Columbus. pdf,2004
20. Vosselman G, Maas H G,2001. Adjustment and filtering of raw laser altimetry data[C]. Proceedings of OEEPEWorkshop on Airborne Laser scanning and Interferometric SAR for Detailed Digital Terrain Models, Stockholm, Sweden
21. Wehr A, Lohr U. Airborne Laser Scanning-an Introduction and Overview[J]. ISPRS, 1999,54(2/3):68-82
22. www.flimap.com
23. www.leica-geosystems.com
24. www.optech.ca
25. www.riegl.com
26. Zhihe Wang, Rong Shu, Weiming Xu, Hongyi Pu, Bo Yao. Analysis and Recovery of Systematic Errors in Airborne Laser System[C]. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences,2008, Vol.ⅩⅩⅩⅦ, Part B1, Beijing
27.戴永江.激光雷达原理[M].北京：国防工业出版社,2002：3—20
28.黄谟涛,翟国君,谢锡君等.多波束和机载激光测深位置归算及载体姿态影响研究[J].测绘学报,2000,29(1)：82—89
29.贾广帅.机载激光雷达系统数据特点和滤波方法研究[D].青岛：山东科技大学,2007
30.赖旭东,万幼川.机载激光雷达距离图像的边缘检测研究[J].红外与激光工程,2005
31.李德仁.摄影测量与遥感的现状及发展趋势[J].武汉测绘科技大学学报,2000,25(1)：1—6
32.李清泉,李必军,陈静.激光雷达测量技术及其应用研究[J].武汉测绘科技大学学报,2000,25(5)：387—392
33.李树楷,薛永琪.高效三维遥感集成技术系统[M].北京：科学出版社,2000
34.李松.星载激光测高仪发展现状综述[J].光学与光电技术,2004,2(6)： 4—6
35.李学友.IMU/DGPS辅助航空摄影测量原理、方法及实践[D].解放军信息工程大学博士学位论文,2005
36.李学友.IMU/DGPS (?)辅助航空摄影测量综述[J].测绘科学,2005：110—113
37.刘经南,张小红.激光扫描测高技术的发展与现状[J].武汉大学学报·信息科学版,2003,28(2)：132—137
38.刘经南,张小红,李征航.影响机载激光扫描测高精度的系统误差分析[J].武汉大学学报·信息科学版,2002,27(2)：111—117
39.刘沛.多源数据辅助机载LIDAR数据处理的关键技术研究[D].北京：中国测绘科学研究院,2008
40.刘艳丰.基于kd-tree的点云数据空间管理理论与方法[D]. 长沙：中南大学2009
41.罗伊萍.LIDAR数据滤波和影像辅助提取建筑物[D].郑州：中国人民解放军信息工程大学,2010
42.吕献林.多源数据辅助机载LiDAR数据生成DEM方法研究[D].武汉：中国地质大学,2009
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