基于高斯与小波的机载测深LiDAR波形分解算法  

An algorithm for Airborne LiDAR Bathymetric Waveform Decomposition Based on the Gaussian Model and Wavelet

作　　者：王贤昆[1,2] 张汉德 董梁 宿殿鹏 亓超 阳凡林 WANG Xian-kun1,2, ZHANG Han-de2, DONG Liang2, SU Dian-peng1, QI Chao1, YANG Fan-lin1,3(1. College of Geomatics, Shandong University of Science and Technology, Qingdao 266590, ShandongProvince, China;2. Northern SeaAirborne Detachment, ChinaMarine Surveillance, Qingdao 266061, Shandong Province, China;3. Key Laboratory of Surveying and Mapping Technology on Island and Reef, National Administration of Surveying, Mapping and Geoinformation, Qingdao 266590, Shandong Province, Chin)

机构地区：[1]山东科技大学测绘科学与工程学院,山东青岛266590 [2]中国海监北海航空支队,山东青岛266061 [3]海岛(礁)测绘技术国家测绘地理信息局重点实验室,山东青岛266590

出　　处：《海洋技术学报》2018年第2期1-6,共6页Journal of Ocean Technology

基　　金：国家自然科学基金资助项目(41376108);国家重点研发计划资助项目(2016YFB0501700;2016YFB0501705)

摘　　要：波形分解是机载测深LiDAR数据处理的关键环节,为水深计算、底质类型反演和水体浑浊度分析等提供基础信息。针对传统测深LiDAR波形分解算法受噪声干扰严重、对微弱及叠加信号分解不准确的问题,提出一种新的波形分解算法。对原始波形经小波滤波后,计算滤波前后尾段波形的差异,估计回波信号的噪声;利用高斯模型,从原始波形数据中不断分解出经LM算法优化参数后的波形分量,直到剩余波形中最大峰值与优化后的参数小于一定阈值。通过南海实测数据进行验证,实验结果表明:该算法分解弱回波能力强,不论在浅水(回波发生叠加)还是深水,其分解精度均优于传统算法。Decomposition of waveform is a key link in airborne LiDAR bathymetry data processing, which can provide the basic information for deriving water depth, inverting seafloor sediment tyoe, and analyzing water turbidity. Traditional waveform fitting algorithms are less robust to noise, and cannot detect weak signals and superposed signals in an accurate way. To overcome these problems, a method was proposed in this paper. Firstly,the proposed algorithm is used to calculate the difference between the last part of the original waveform and the waveform after wavelet threshold denoising. Then, the Gaussian model is adopted to continuously extract Gaussian components which are optimized by the LM algorithm. Then this algorithm is tested by measured data obtained from the South China Sea, demonstrating that it can detect weak signals. The experiment results show that,whether in shallow or deep water, the fitting precision of the proposed algorithm outperforms the traditional algorithms.

关 键 词：小波阈值去噪 波形分解 机载测深LiDAR LM算法 

分 类 号：P229[天文地球—大地测量学与测量工程]