差分层析SAR四维成像技术研究

项目名称： 差分层析SAR四维成像技术研究

项目编号： No.41271459

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 董臻

作者单位： 中国人民解放军国防科学技术大学

项目金额： 75万元

中文摘要： D-TomoSAR技术能够对观测对象实现四维（空间－时间）成像，在对地观测领域具有巨大的应用潜力。当前D-TomoSAR系统主要由单雷达重轨飞行构建，存在两个难题：（1）观测数据在垂直基线－观测时刻二维上分布稀疏，即小样本问题；（2）由大气扰动等时间去相关等因素在SAR 单视复图像中引入的相位噪声问题。前者会在信号重构中导致病态问题，后者会降低观测数据的信噪比，二者解决不好将会影响信号估计精度，降低对目标位置和形变的解析能力。此外，目前在形变估计方面的研究还主要针对线性形变，对非线性形变问题的研究不够深入。本项目首先根据相位噪声的空－时特性，研究高精度的相位噪声抑制方法；再根据D-TomoSAR信号的稀疏表示特性，在CS理论和FM信号估计理论指导下，研究目标位置和形变函数的精确估计方法。项目研究将充分借鉴雷达信号处理领域的研究成果，尝试通过学科交叉促进D-TomoSAR技术的实用化进程。

中文关键词： 差分层析合成孔径雷达；相位噪声；压缩感知；稀疏重构；非线性形变

英文摘要： Differential SAR tomography (D-TomoSAR) has the 4-D (spatial and temporal dimension) imaging ability, which makes it greatly potential for earth observation. At present, D-TomoSAR is usually constituted by repeat-pass missions of single-antenna SAR. Two problems will be resulted by this kind of acquisition method: the 2-D data set sparse distribution characteristic in baseline-time plane and the inevitable phase error associated with atmospheric disturbance for the years-long temporal span of SAR observation. The former may cause ill-posed trouble during signal reconstruction. The latter may decrease SNR of the data. Both can significantly degrade the performance of D-TomoSAR if not properly dealt with. Besides, current researchs on temporal deformation estimation are more concentrated on linear motion, whereas more attention should be focused on nonlinear motion which often happens realistically. Taking all the aforementioned aspects into account, this project firstly studies techniques to suppress phase error based on its space-time distribution characteristic. Then according to D-TomoSAR signal's natural property of sparse representation, the sparse reconstruction approaches are investigated in the framework of Compressive Sensing(CS) and Frequency Modulaiton(FM) signal theories to estimate the scatters' pos

英文关键词： Differential Tomography SAR(D-TomoSAR)；phase noise；Compressive Sensing(CS)；Sparse Reconstruction；Nonlinear deformation