毫米波全息成像中的部分发育散斑模型

Partially Developed Speckle Model for Millimeter-Wave Holographic Imaging

建立了包含镜面反射分量的毫米波全息成像中的部分发育散斑模型。将部分发育的散斑模型与毫米波全息成像的卷积过程相结合,推导了等效散射中心个数,建立了散斑对比度与高斯粗糙面均方根高度、相关长度和成像分辨率的关系。基于近场物理光学法,对随机粗糙面的毫米波全息散斑图样进行了蒙特卡罗仿真和散斑对比度分析。结果表明,当等效散射中心个数较少时,该模型与随机积分法及仿真所估计的散斑对比度一致,优于传统模型的估计结果。

In this paper, a partially developed speckle model for millimeter-wave holographic imaging with specular reflection is established. The partially developed speckle model is combined with the convolution process of millimeter-wave holographic imaging. The number of equivalent scattering centers is deduced, and the relationship among speckle contrast, root-mean-square height, correlation length, and imaging resolution of a Gaussian rough surface is established. The Monte-Carlo simulation experiment and the speckle contrast analysis are conducted on the millimeter holographic speckle patterns of a random rough surface based on the near-field physical optics method. The results show that when the number of equivalent scattering centers is small, the speckle contrast estimated using the proposed model is consistent with those estimated using the stochastic integral method and the simulation experiment, which is superior to the estimation results of the conventional models.