Mach-Zehnder干涉仪条纹成像多普勒激光雷达风速反演及视场展宽技术

发布时间：2018-08-11 09:04

【摘要】：相对于传统多普勒鉴频器Fabry-Perot干涉仪,Mach-Zehnder干涉仪(MZI)具有透过率高、直线条纹易于探测、可进行视场展宽等优点.本文设计了基于条纹成像MZI的非相干多普勒测风激光雷达系统,构建了风速反演的数学模型,利用MZI视场展宽技术优化了激光雷达系统的性能.数值仿真实现了MZI鉴频系统干涉条纹图样的理想输出,采用Sine Sqr函数拟合法获取了高精度的多普勒频移前后干涉条纹的移动距离,并通过视场补偿减小了入射角对MZI光程差的影响,从而实现视场展宽.结果表明:采用Sine Sqr函数拟合法可获得在±100 m·s-1的径向风速范围内0.45 m·s-1的风速误差,克服了条纹重心法反演风速不稳定性的缺点;视场展宽技术在不降低鉴频性能的情况下,能最大补偿1°的视场角.MZI条纹成像多普勒激光雷达应用技术的探讨将为中高层大气风速激光雷达测量系统的实际开发奠定良好的基础.
[Abstract]:Compared with the traditional Doppler frequency discriminator Fabry-Perot interferometer, (MZI) has the advantages of high transmittance, easy detection of linear stripes and wide field of view. In this paper, the incoherent Doppler wind lidar system based on fringe imaging MZI is designed, and the mathematical model of wind speed inversion is constructed. The performance of the laser radar system is optimized by using the MZI field broadening technique. The ideal output of interference fringe pattern of MZI frequency discriminator system is realized by numerical simulation. The moving distance of interference fringe before and after high precision Doppler frequency shift is obtained by Sine Sqr function fitting method. The influence of incident angle on MZI optical path difference is reduced by field of view compensation, so that the field of view can be widened. The results show that the wind speed error of 0.45 m / s ~ (-1) in the range of 卤100m / s ~ (-1) of radial wind speed can be obtained by using Sine Sqr function fitting method, which overcomes the shortcoming of inversion of wind speed instability by the fringe barycenter method, and the field of view broadening technique does not reduce the frequency discriminating performance. The discussion of the application technology of the field of view angle. MZI fringe imaging Doppler lidar with maximum compensation of 1 掳will lay a good foundation for the practical development of the measurement system of the middle and upper atmosphere wind speed lidar.
【作者单位】：西安理工大学机械与精密仪器工程学院;
【基金】：国家自然科学基金青年科学基金(批准号:61205189)资助的课题~~
【分类号】：TN959.4

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