基于稀疏贝叶斯方法的THz-SAR振动目标成像研究

项目名称： 基于稀疏贝叶斯方法的THz-SAR振动目标成像研究

项目编号： No.61302148

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 邓彬

作者单位： 中国人民解放军国防科学技术大学

项目金额： 28万元

中文摘要： 目标振动蕴含着对识别极为有利的信息，SAR地面振动目标成像对战场侦察、精确制导、交通监视、维稳反恐等具有重要意义，但存在两个难题：一是振动幅度小，多普勒效应弱；二是振动对多普勒调制机理复杂，成像难度大。对此，本项目首先引入THz技术以增强微多普勒效应，然后基于振动-散射中心混合模型从回波域构建THz-SAR观测模型，将成像转化关于振动参数和散射系数的Fredholm方程求解逆问题。最后，在贝叶斯框架下开采目标稀疏先验，研究先验支持下的快速全局优化算法。这一思路避免了传统杂波抑制、距离徙动校正等复杂处理环节，能够实现目标振动和散射参数的最优估计，获取目标散射系数在空间位置和振动参数维度上的分布即超立方体图像，达到SAR图像中模糊消除和特征凸显的效果。项目将为SAR特种目标探测提供理论支撑，同时推动稀疏贝叶斯应用研究的发展。

中文关键词： 太赫兹；振动目标；稀疏表示；贝叶斯；

英文摘要： Target vibration conveys favorable information for recognition, and imgaing vibrating targets with synthetic aperture radar (SAR) bears considerable significance to battlefield reconnaissance, precision guidance, traffic monitoring and antiterrorism. However, vibration has minor amplitude and Doppler, and it will induce complex modulation as well as image defocusing, hence difficult for detection. Therefore, we at first propose to enhance micro-Doppler by incorporating THz techniques, and then build in the return domain a measurement model based on the hybrid vibration-scattering center. Thus image reconstruction is reformulated as a Fredholm equation inverse problem for finding vibration parameters and scattering coefficients. In the end, target sparse priors are exploited and used for fast and global optimization in the Bayesian theory framework. The idea avoids conventional difficult procedures, e.g. clutter suppression and range cell migration correction, directly realizes optimal estimation of vibration and scattering parameters, and can obtain the distribution of scattering coefficients in both space and vibration-parameter dimensions, hence mitigating blurs in original SAR images and enhancing target features. This project will not only provide supports for SAR sensing of special targets, but also can pro

英文关键词： Terahertz；vibration targets；sparse representation；Bayesian；