解相关曲线的形态特性研究

解相关曲线的形态特性研究 Morphological Characteristics of Decorrelation Curves in Larger Distance Range 杨玥 YANG Yue 1 first-author 张东 ZHANG Dong 1 杨艳 YANG Yan 1 秦前清 QIN Qianqing 2 孙尽尧 SUN Jinyao 1 武汉大学物理科学与技术学院 武汉大学物理科学与技术学院 School of Physics and Technology,Wuhan University School of Physics and Technology,Wuhan University 武汉大学测绘遥感信息工程国家重点实验室 武汉大学测绘遥感信息工程国家重点实验室 State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing,Wuhan University State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing,Wuhan University 对理想情况和非理想情况下的解相关曲线的形态特性作了理论上的推导和讨论.推导了标准的斑点解相关曲线呈高斯曲线形态的理论依据和假设简化前提,讨论了当散射回波中存在相干散射成分时,对解相关规律产生的影响,此时解相关率下降变缓,相关长度也会相应地延长.基于以上理论基础以及散射回波各向同性的特点,本文通过计算斑块的层内横向解相关曲线来预测其所在位置的层间解相关规律,用于估算相邻两帧超声图像间的距离,以实现距离校准的目的.本方法不再依赖于标准的斑点解相关曲线而实现层间测距,算法更为灵活,测距范围扩展至1 mm至5 mm.实验结果表明,本文提出的方法具有一定的精确性和稳定性. This paper studies the morphological characteristics of decorrelation curves under ideal and non-ideal condition. It gives the theoretic explanation and the premise of the simplifying assumption that the standard speckle decorrelation curves can be well approximated by Gaussian curves. However,the existence of coherent scattering in scattering echo will affect the decorrelation regulation,leading to slower the decorrelation and increase the correlating length. Based on the discussion above and the isotropy of scattering echo,the paper calculates the lateral speckle decorrelation plot as a reference to predict the rate of speckle decorrelation in elevation direction. From the patch-specific decorrelation,the distance estimation for successive b-scan frames is achieved. The method can measure elevation distance without relying on standard speckle decorrelation curves. The calculation results show that the method can handle larger distance（ 1-5 mm） estimation with accuracy and stability. 解相关曲线 瑞利散射条件 相干散射 层间测距 decorrelation curve Rayleigh scattering condition coherent scattering elevational displacement estimation 10.14188/j.1671-8836.2015.05.004 TP391.41 国家重点基础研究发展规划（973）项目资助（2011CB707900） 2015-05-01 2021-03-31 5 61