相干多普勒测风激光雷达回波信号算法设计及验证

发布时间：2018-07-05 07:06

本文选题：相干测风激光雷达 + 多普勒效应　；参考：《南京邮电大学》2017年硕士论文

【摘要】：大气风场信息是大气的一个重要参数,其在数值天气预报、气象气候学研究、环境监测和军事航空应用等领域都有着十分重要的作用。多普勒测风激光雷达具有测量精度高、时空分辨率高以及响应速度快等优点,其应用范围十分广泛,包括机场测风、风切变探测、大气湍流探测及追踪、飞机尾迹涡流探测等。尤其是风切变探测,它对提高飞行安全有重大意义。而如何有效判别和提高测风激光雷达系统反演出的大气风场信息的正确性,就是本文的研究重点。本文针对相干多普勒测风激光雷达的回波信号进行了有效分析。一是在回波信号功率谱的基础上,对比分析了两种不同的去噪方法,同时还在信号载噪比理论研究的基础上提出了新的载噪比算法,并通过对比实验验证了该算法的正确性,此外,还验证了该载噪比算法对上述两种不同的去噪方法均适用。二是在回波信号载噪比的基础上,对测风激光雷达回波信号的有效性提出了新判据,其能进一步缩小回波信号的有效区间,从而大大提高激光雷达系统反演出的风场信息的正确性。三是针对相干多普勒测风激光雷达的工作环境,在回波信号载噪比的基础上,提出了系统自动雨刷功能,该雨刷功能能有效清除测风激光雷达系统的出光端面障碍,从而大大提高回波信号的可靠性。
[Abstract]:Atmospheric wind field information is an important parameter of the atmosphere, which plays an important role in the fields of numerical weather forecast, meteorological and climatological research, environmental monitoring and military aviation application. Doppler wind lidar has many advantages, such as high measurement precision, high spatial and temporal resolution and fast response speed. It has a wide range of applications, including airport wind measurement, wind shear detection, atmospheric turbulence detection and tracking, aircraft wake eddy current detection and so on. Especially wind shear detection is of great significance to improve flight safety. How to effectively distinguish and improve the correctness of the atmospheric wind field information of the wind lidar system is the focus of this paper. In this paper, the echo signal of coherent Doppler wind lidar is analyzed effectively. First, on the basis of the power spectrum of echo signal, two different denoising methods are compared and analyzed. At the same time, a new carrier noise ratio algorithm is proposed based on the theoretical research of signal carrier to noise ratio, and the correctness of the algorithm is verified by comparison experiments. In addition, it is verified that the carrier noise ratio algorithm is applicable to the two different denoising methods mentioned above. Secondly, on the basis of the carrier to noise ratio of the echo signal, a new criterion is proposed for the validity of the echo signal of the wind measuring lidar, which can further reduce the effective range of the echo signal. Therefore, the correctness of wind field information in the inverse performance of lidar system is greatly improved. Third, aiming at the working environment of coherent Doppler wind lidar, a system automatic wiper function is proposed on the basis of echo signal carrier to noise ratio. The wiper function can effectively clear the light out of the wind measuring lidar system. Therefore, the reliability of echo signal is greatly improved.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN958.98

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