利用光波湍流效应的相关性特征获取风廓线的方法研究

发布时间：2018-04-28 19:33

本文选题：风速 + 大气湍流　；参考：《中国科学技术大学》2017年硕士论文

【摘要】：本文首先依据Rytov近似,对大气测量中常用的二阶统计矩进行了推导,同时对风速反演的重要理论依据泰勒湍流冻结假设作出了说明。接着以DCIM雷达的原理为基础构建了水平探测理论模型,用于实现水平横向风速廓线以及湍流强度廓线的反演。根据Rytov近似以及泰勒湍流冻结假设,对该理论模型的理论公式进行了推导,得到了以不同距离的前向散射光为信标的水平路径上G倾斜角的相关表达式。在此基础上引出了反演中所采用的一些基本方法,并对表达式中的权重函数进行了分析。基于上述方法以及分析结论,木文提出了一种矩阵变换与数值近似相结合的反演算法,用于联合反演水平横向风速廓线以及湍流强度廓线。对于该算法,本文对其进行了多种湍流条件以及风速条件下的仿真验证,对实际中可能存在的问题包括时间分辨率与空间分辨率,测量误差或噪声的处理也在仿真中进行了相应的分析。除此之外,本文对测量中存在的盲区问题以及更受关注的垂直反演问题对本文所采用之方法的影响进行了讨论。综上所述,在盲区较小的情况下,对于水平方向的反演,本文所提出的方法能够得到不同湍流与风速条件下的湍流强度廓线以及风速廓线,为反演大气湍流强度以及风速提供了一种新思路。
[Abstract]:In this paper, the second-order statistical moments commonly used in atmospheric measurements are deduced based on the Rytov approximation, and the important theory of wind speed inversion is explained according to Taylor's turbulence freezing hypothesis. Then, based on the principle of DCIM radar, a theoretical model of horizontal detection is constructed, which can be used to realize the inversion of horizontal transverse wind profile and turbulence intensity profile. Based on the Rytov approximation and Taylor's turbulence freezing hypothesis, the theoretical formula of the theoretical model is derived, and the correlation expression of the G tilt angle on the horizontal path with forward scattering light at different distances as the beacon is obtained. On this basis, some basic methods used in inversion are elicited, and the weight function in the expression is analyzed. Based on the above method and the analysis results, a new inversion algorithm combining matrix transformation and numerical approximation is proposed, which can be used for the joint inversion of horizontal transverse wind profiles and turbulent intensity profiles. For this algorithm, the simulation results under various turbulence and wind speed conditions are given. The possible problems in practice include temporal resolution and spatial resolution. The processing of measurement error or noise is also analyzed in simulation. In addition, the problem of blind area in measurement and the influence of the more concerned vertical inversion problem on the methods used in this paper are discussed in this paper. To sum up, in the case of small blind area, the method proposed in this paper can obtain the turbulence intensity profile and wind velocity profile under different turbulence and wind speed conditions. It provides a new idea for inversion of atmospheric turbulence intensity and wind speed.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P407

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