项目名称： 相干场成像高精度目标重构技术研究

项目编号： No.61505248

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 曹蓓

作者单位： 中国科学院西安光学精密机械研究所

项目金额： 20万元

中文摘要： 相干场成像是一种高分辨率激光主动成像技术，目标重构作为其核心关键技术直接影响系统的成像能力。本项目针对影响目标成像质量的关键因素：上行链路大气湍流扰动、回波噪声扰动、多种频率漂移及测量误差等，采用理论推导、数值模拟与实验验证的研究方法，系统开展提高成像质量、缩短成像时间的研究。在多光束发射阵列下，首先设计新的全局相位闭合算法，在消除大气随机相位误差同时抑制光强闪烁效应、提高真实相位的恢复精度；之后建立融合回波处理模型抑制噪声、提高信噪比；并提出新的迭代全相位谱目标重构算法，在湍流环境中校正多种误差、提高重构的鲁棒性及图像质量；同时将空域NUFT及压缩感知方法应用到相干场成像中，突破二维采样定理、实现发射阵列的稀疏设计，从而缩短成像时间、降低激光器功率需求。通过本项目研究将有力提升湍流环境中系统的成像能力，为傅里叶望远镜的优化设计与工程研制提供技术依据，具有重要的理论研究意义与应用价值。

中文关键词： 相干场成像；傅里叶望远镜；目标重构

英文摘要： Coherent field imaging is an active imaging technique with high-resolution. As a core part, object reconstruction technique imposes significant influence on the imaging capability of the system. Based on thorough analysis on key factors related to the imaging process, comprehensive research is accomplished in this project. The research work is carried out from two aspects: enhance the imaging quality and reduce the imaging time in order to achieve the reconstructed image of the object precisely in the turbulence environment. The simulation study and experimental verification method are used. Firstly, a new global phase closure algorithm is designed to cancel out the random phase error and scintillation at the same time, from which the true phase is extracted with higher accuracy; then a combined processing model for the received signal is established to suppress noises and enhance SNR effectively. And an iterated all-phase FFT reconstruction method is presented to correct the practical frequency and measurement error, promoting the robustness of reconstruction process, eventually obtaining high-precision image. NUFT method and compressed sensing theory are introduced into the project’s research, which can bring major breakthrough in sparse design of transmitter array and reduction of the imaging time, hereby lowering the power of laser and cost of coherent field imaging system. Based on this project, the imaging capability of coherent field imaging system can be highly promoted, while providing valid technical reference for optimization design and realization of Fourier telescope. Therefore, the research work is of significant importance in theoretical and application aspects.

英文关键词： coherent field imaging;Fourier telescope;object reconstruction