【作者】 李岩；

【导师】 张中华；

【作者基本信息】 哈尔滨工业大学 ， 物理电子学， 2013， 硕士

【摘要】 突变风场往往令人猝不及防，很多情况下给人类活动带来巨大危害，尤其是晴空下小尺度的风切变，利用传统的微波雷达进行探测其准确性不足以满足要求。激光测风雷达具有更高的探测精度和空间分辨率，可与微波相结合更好的实现时空的风场探测。本文针对探测对象和探测方法进行了理论分析、数据仿真和试验研究。首先，从环境特点出发进行了探测体制的分析和激光雷达波段的选取，确定了1.55m相干探测体制；然后，研究了对飞机造成较大影响的几种危害风场的分类，建立了风场的物理模型，并进行了数学仿真，一定程度上再现了风场的结构；最后，对外差探测方式进行了细致的研究，从提高外差探测系统信噪比的角度，研究了不同因素对外差效率的影响、平衡式探测的原理和本振光功率对信噪比的影响，建立1.55m相干探测试验系统，分别进行了最佳本振光功率试验和平衡式探测与单元探测对比试验，得到试验结果与理论分析相一致。更多还原

【Abstract】 In the wind field study, mutations are often caught off guard, what brings great harmto human activities in many cases, especially the small-scale wind shear under clear skies.The accuracy of conventional microwave radar detection can not meet the humansecurity requirements. Laser wind radar has higher detection accuracy and spatialresolution, which can be combined with the microwave to measure wind speed in spaceto achieve better results.This paper analyzes the working principle of laser radar, and analyzes objectdetection and detection methods with theoretical analysis, simulation and experimentalresearch data. Firstly, started from the environmental characteristics, according to thescale of tracer particles, the band and detection methods were selected, which was finallydetermined to use the1.55m coherent detection systems. Secondly, we studied severalclassification of wind fields which were harmful to the aircraft, then established aphysical model of the wind field, and carried out mathematical simulation, and resultsshowed the structure of the reproduction of the wind field to some extent. Finally, we dida detailed study for the heterodyne detection methods. From improving the signal tonoise ratio of heterodyne detection system perspective, the effects of different factors, theinfluence of external differential efficiency, balanced detection principle and the LOsignal to noise ratio of the optical power were studied. We built a1.55um coherentdetection test system, and do the best local oscillator optical power test and balanceddetection and contrast detection unit test respectively, which turned out the test results areconsistent with the theoretical analysis.更多还原