QQ客服 官方微博 反馈留言

题名	基于Fizeau干涉仪的多普勒测风激光雷达技术研究
作者	卜令兵
学位类别	博士
答辩日期	2007
授予单位	中国科学院上海光学精密机械研究所
导师	陈卫标
关键词	多普勒激光雷达 直接探测 条纹技术 Fizeau干涉仪 双边缘检测 DFP干涉仪
其他题名	Studies of Doppler Wind Lidar Technique Based on Fizeau Interferometer
中文摘要	大气风速测量在天气、环境和军事等领域均具有重要的作用，由于多普勒测风激光雷达具有高时空分辨的特点，是目前风场测量中的新技术。直接探测激光雷达相对相干探测激光雷达，不受大气中气溶胶含量的限制，更适宜高空探测和全球风场测量。本文根据多普勒测风激光雷达的技术和发展趋势，选择了基于直接探测技术的多普勒激光雷达测风方案。低空使用多光束Fizeau干涉仪利用气溶胶散射信号进行风速探测，而高空使用双边缘技术利用大气分子散射信号进行风速探测，该方案综合利用条纹技术和边缘技术的优势，探测范围覆盖对流层和平流层底部。文中对多普勒测风激光雷达系统进行了必要的理论和实验工作，建立了多普勒测风激光雷达工程样机，取得了初步的实验成果。 文中对Fizeau干涉仪的光谱特性进行研究，优化设计了Fizeau干涉仪。研制了基于PID温控器的两级温控系统，温控精度达到±0.002℃，对应干涉仪的中心频率变化小于0.7 MHz。采用632.8nm激光与355nm激光，分别对Fizeau干涉仪光谱进行了实验测量，通过干涉仪腔长扫描的方法，获得了实际加工的Fizeau干涉仪的光谱参数。实验结果发现了入射光发散角对光谱分辨率的影响，通过选用更小芯径的能量传输光纤来匹配Fizeau干涉仪的入射光发散角的要求，提高了光谱分辨率。提出了多通道光电倍增管阵列结合并行高速数据采集卡进行后向散射信号探测的方案，并模拟了基于Fizeau干涉仪与光电倍增管阵列组合方案的风速测量结果，数值模拟结果显示风速测量准确度可以达到小于1m/s的要求。对风速反演算法进行了研究，对比了三种风速反演的结果，针对各自特点提出了改进方法。编制了数据采集控制和数据处理软件。 为验证系统可行性，完成了大量的后向散射信号接收实验。通过偏振分束和合束，解决了光纤退偏问题，提高了后向散射信号的接收效率。对激光频率稳定性进行了实验研究，提出了测风激光雷达中去除激光频率抖动影响的方法。利用零速度硬靶散射测定了激光雷达样机的系统误差。使用提出的多通道倍增管和并行数据采集卡的方案对大气后向散射进行了探测，得到了大气后向散射条纹剖面以及不同高度处条纹中心信息，最后，对大气风场进行了测量得到了1.5Km以下的大气风场剖面。根据大气后向散射光谱对气溶胶散射与分子散射进行分析，得出了大气散射比。 论文最后介绍了完成的基于分子散射测风的DFP系统以及车载测风激光雷达工程样机，系统具备对流层和平流层底部的风速剖面测量能力
英文摘要	Wind measurement is very important in many fields such as climate, environment and military. Due to both high temporal and spatial resolutions, Doppler wind lidar becomes the most attractive wind-sensing instrument. Direct-detection wind lidar has merits on high altitude and global wind sounding comparing to coherent wind lidar because of little sensitivity to aerosol concentration. Studies of Doppler wind lidar based on direct-detection technique are paied attentaion in this dissertation according the trend of Doppler lidar. In the low altitude, a multi-beam Fizeau interferometer is used to analyze the backscattering signal of aerosol, and in the higher altitude, a double Fabry-Perot(DFP) is used to analyze the backscattering signal of molecule, so the advantage of combining two techeniques（edge and fringe technique）is fully utilized. Experimental works are conducted for the Doppler wind lidar, and the engineering prototype is constructed. Spectral characteristics of Fizeau interferometer are studied, and the optimized design of the interferometer is implemented. The temperature controller and frequency feedback are constructed. The temperature stability of less than ±0.002℃ with two stages of PID controlling is obtained, which it is corresponding to the frequency stability of less than 0.7 MHz at 355 nm. Spectral parameters are abtained by scanning Fizeau interferometer with both lasers of 632.8 nm amd 355 nm, respectively. The effection of divergence angle to interferometer is observed, and it is resolved by replacing a smaller core diameter fiber to get smaller divergence. The detection unit combining with a multi-anode detector and high-speed synchronous A/D cards is used to detect backscattering signal. Numberical simulation with the detection scheme is implemented, and the results show that the wind error of less than 1 m/s can be reached. The retrieval algorithams of wind vector is studied. The softwares of data acquirement and data processing are developed. Many measurements of backscattering signal are analyzed with the propotype. The depolarization of receiving signal is ovecomed by polarized beam spiliting and combining technique, therefore the collecting efficiency is improved. The effect due to the stability of the laser frequency is observed, and the method of minimizing the effect of frequency jitter is proposed. Zero velocity hard target experiment was done to evalue the system error. The profiles of the backscatter signal are sounded and the fringe spectra of different altitudes are retrieved. The wind profile under the range of 1.5 km is obtained. The backscatter ratio is also gotten from the received signals. The last section of this dissertation describes double Fabry-Pero (DFP ) unit and the propotype of the mobile Doppler lidar system. It is implied that the system has the ability of measuging wind in both troposphere and low stratosphere
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15308]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	卜令兵. 基于Fizeau干涉仪的多普勒测风激光雷达技术研究[D]. 中国科学院上海光学精密机械研究所. 2007.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。