壁面散射对激光多普勒测速术中信噪比的影响。

Effect of wall scattering on SNR in laser Doppler anemometry.

作者信息

Mishina H, Vlachos N S, Whitelaw J H

出版信息

Appl Opt. 1979 Jul 15;18(14):2480-5. doi: 10.1364/AO.18.002480.

DOI:10.1364/AO.18.002480

PMID:20212686

Abstract

A method, based on geometrical optics and diffraction theory of Gaussian beams, is presented and describes the image formation of scattered light in laser Doppler anemometry. The intensity distributions of the images of scattered light from both the control volume and a nearby transparent wall are given as a function of distance between the control volume and the wall, collecting lens aperture radius, magnification, incident beam radius, and beam angle. The effect of the scattered light from the wall surface on the Doppler SNR is discussed. The minimum distance close to the wall for which a good signal quality can be obtained is defined and quantitatively determined. The results show that this distance is strongly affected by the aperture size of the collecting lens and beam angle.

摘要

提出了一种基于几何光学和高斯光束衍射理论的方法，该方法描述了激光多普勒测速术中散射光的成像。给出了控制体积和附近透明壁面散射光图像的强度分布，其作为控制体积与壁面之间的距离、收集透镜孔径半径、放大率、入射光束半径和光束角度的函数。讨论了壁面散射光对多普勒信噪比的影响。定义并定量确定了能获得良好信号质量的靠近壁面的最小距离。结果表明，该距离受收集透镜孔径大小和光束角度的强烈影响。