全光纤M-Z干涉仪的高灵敏度与大动态范围多普勒激光雷达风场探测技术

发布时间：2018-03-29 06:05

本文选题：多普勒激光雷达　切入点：光纤Mach-Zehnder干涉仪　出处：《光谱学与光谱分析》2017年03期

【摘要】：多普勒测风激光雷达是大气风场探测的重要手段之一。通过检测风速导致的大气后向散射谱的多普勒频移从而实现风速的探测。由于受鉴频器本身特性的影响,高灵敏度与大动态范围的探测一直是大气风场探测的难点。提出采用双光纤Mach-Zehnder干涉仪(FMZI)作为多普勒激光雷达的鉴频器件,设计两路不同动态范围及风速探测灵敏度的FMZI鉴频器同时对大气回波信号进行鉴频。采用小光程差(13.7 cm)、大动态范围(±100 m·s~(-1))鉴频光路FMZI-2对风速区间进行定位,大光程差(74.8 cm)、高探测灵敏度(2.62%/(m·s~(-1)))的鉴频光路FMZI-1进行风速精细探测,从而实现大动态范围高灵敏度的风场探测。利用标准大气模型对不同参数条件下的系统灵敏度、系统探测的信噪比及风速误差进行仿真分析。结果表明,该系统可以实现±100 m·s~(-1)大动态范围内风速误差小于1 m·s~(-1)的大气风场探测,为大动态范围高灵敏度测风激光雷达的发展进行了有益的探索。
[Abstract]:Doppler wind lidar is one of the important methods to detect the atmospheric wind field. By detecting the Doppler frequency shift of the atmospheric backscattering spectrum caused by the wind speed, the detection of the wind speed can be realized. The detection of high sensitivity and large dynamic range is always a difficult problem in the detection of atmospheric wind field. A dual-fiber Mach-Zehnder interferometer (FMZI) is proposed as a frequency discriminator for Doppler lidar. Two FMZI frequency discriminators with different dynamic range and detection sensitivity of wind speed are designed to detect the frequency of atmospheric echo signals simultaneously. The large dynamic range (卤100m / s ~ (-1)) frequency discriminant path FMZI-2 is used to locate the wind speed interval by using a small optical path difference of 13.7 cm ~ (-1) and a large dynamic range (卤100m / s ~ (-1)). The large optical path difference is 74.8 cm ~ (-1), and the high detection sensitivity is 2.62 / m ~ (-1) / m ~ (-1). The fine detection of wind speed is carried out by the frequency discriminating light path (FMZI-1), and the high sensitivity wind field detection in a large dynamic range is realized. The system sensitivity under different parameters is obtained by using the standard atmospheric model, and the sensitivity of the system under different parameters is obtained by using the standard atmospheric model. The signal to noise ratio (SNR) and wind speed error of the system are simulated and analyzed. The results show that the system can detect the atmospheric wind field with the wind speed error less than 1 m / s ~ (-1) in the large dynamic range of 卤100 m / s ~ (-1). It is useful for the development of high sensitivity wind lidar in large dynamic range.
【作者单位】：西安理工大学机械与精密仪器工程学院;
【基金】：国家自然科学基金项目(61205189,61275185,41627807) 陕西省自然科学基金项目(2014JQ5174)资助
【分类号】：TN958.98

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