摘要
设计了一套基于光子计数探测体制的激光雷达水深探测系统,该系统工作波长为532 nm,单脉冲激光能量为0.5μJ,脉冲宽度为400 ps,激光重频为10 kHz,单光子探测器死时间为22 ns,时间间隔分辨率为50 ps。首先介绍了光子计数探测体制激光雷达用于水深探测的基本原理及其相对于传统机载激光测深雷达的优越性;然后分析了水底回波信号产生的平均光电子数与系统单脉冲激光能量的关系,从而理论求取出该系统的极限测深能力为3.7 m左右。最后进行了外场实地试验,对所获激光雷达点云数据进行滤波和解算,成功测得了透明盘深度为1.2 m的浑浊水体深度为2 m以内的水下信息。
A single wavelength(532 nm), short-pulse(400 ps), low pulse energy(0.5 μJ), high pulse repetition rate(10 kHz), short dead time of detector(22 ns) and high resolution of time interval(50 ps)photon counting laser bathymetry system was designed. The principle of photon counting laser bathymetry and its superiority to the typical airborne laser bathymetry was introduced. The relationship between the average number of photoelectrons generated at the receiver and the transmitted laser pulse energy was analyzed, indicating that the bathymetry capability of the system was about 3.7 m. Experiments were conducted in a pond with a Secchi depth of 1.2 meters, and the underwater information down to 2 m depths were successfully obtained by filtering and solving the point cloud data.
引文
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