物理学报2016,Vol.65Issue(7):070704-1-070704-7,7.DOI:10.7498/aps.65.070704
荧光激光雷达技术探测水面油污染系统仿真研究∗
Simulation of fluorescence lidar for detecting oil slick
摘要
Abstract
In order to measure the oil pollution on water surface, a fluorescence lidar model system based on laser induced fluorescence is put forward for detecting oil slick. The system model and fluorescence detecting principle are described in detail. According to the properties of detected material, wavelength of laser and filter of receiving system are adopted to ensure that the lidar system is operated at the peak wavelength. Following the development trend of miniaturization in the world, using single laser and intensified charge-coupled devices, a small fluorescence detecting system is designed. FTSS 350-50 laser made by CRYLAS company, with compact dimension, low weight and excellent energy efficiency, and PI-MAX4 intensified charge-couple devices made by Princeton Instruments company, with good time resolution characteristic, are selected to produce laser as a launch device and to inspect fluorescence lifetime and capture image as a receiving device, respectively. The laser excitation wavelength, the energy of laser, the center wavelength and bandwidth of filter, the received echo fluorescence signals, the detected concentration and distance are discussed in detail by means of the instance for oil on water surface. Through analyzing the relationship between the energy of laser single pulse and the detection concentration and by combining with the parameters of fluorescence lidar system and fluorescence lidar equation, the detecting ability of system model, signal-to-noise ratio, etc. are simulated particularly. A numerical simulation of the signal-to-noise ratio of the fluorescence particles is conducted particularly so that the detectable capacity of system designed could be described better. The results show that the signal-noise ratio of system which is operated during the night is superior to in daytime in the same single pulse energy case and that the detected range becomes gradually longer as the energy of laser improves with the same signal-noise ratio case. The required single pulse energy to support system is calculated, and further verifies the feasibility of the lidar system. The test results of the sample show that in the daytime, the design of fluorescence lidar model, with a Nd:YAG laser of 50 µJ single pulse energy and 355 nm wavelength serving as an excitation light source, with a collection device placed at a distance of 7 m, can satisfy the requirements for detecting oil pollution on the water surface in laboratory, and its signal-noise ratio can reach 10. In view of the actual surface fluorescence lidar detection requirements, the method of increasing the laser power is proposed. A real system with 50 mJ single pulse energy at a distance of 230 m has nearly the same performance as the laboratory lidar system, which could provide a valuable guidance for designing a real system.关键词
激光诱导荧光/荧光激光雷达/水面油污染/信噪比Key words
laser induced fluorescence/fluorescence lidar/oil slick/signal-to-noise ratio引用本文复制引用
景敏,华灯鑫,乐静..荧光激光雷达技术探测水面油污染系统仿真研究∗[J].物理学报,2016,65(7):070704-1-070704-7,7.基金项目
国家自然科学基金(批准号:61275185)资助的课题 (批准号:61275185)