基于稀疏分解的SAR射频干扰抑制与回波重构技术

项目名称： 基于稀疏分解的SAR射频干扰抑制与回波重构技术

项目编号： No.61302146

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： 李悦丽

作者单位： 中国人民解放军国防科学技术大学

项目金额： 22万元

中文摘要： 超宽带合成孔径雷达（UWB SAR）具备强的穿透探测隐蔽目标能力，但同频段电视、广播和通信信号对雷达造成严重射频干扰（RFI），且干扰具有时变和空变性。以干扰近似平稳为基础发展起来的传统RFI抑制技术不能有效解决非平稳RFI抑制问题。 为此，本项目提出基于稀疏分解的非平稳RFI抑制和回波重构技术，技术途径为：首先采用时频分析技术研究UWB SAR射频干扰特征，提出与干扰相匹配的冗余字典代替传统正交基，然后基于稀疏分解算法估计RFI干扰，对去除RFI后的回波基于信号和目标特征进行重构，提高成像质量。项目需重点研究稀疏分解的快速算法和RFI抑制技术的面目标成像适用性问题，提高RFI估计和回波重构的计算效率，增强算法对含噪数据的稳健性。时频冗余字典能实现对包括时变干扰在内的射频RFI的准确表征，回波重构技术可解决传统RFI抑制技术的高旁瓣问题，研究有望在RFI抑制问题上取得突破。

中文关键词： 合成孔径雷达；稀疏分解；自适应谱线增强器；独立分量分析；匹配追踪

英文摘要： Ultra Wide Band (UWB) Synthetic Aperture Radar (SAR) owns an ability to detect the targets shaded in the foliage or under the ground. But the television, radio and communication signals which operating at VHF/UHF band bring severe Radio Frequency Interferences （RFI） to UWB SAR. Since the space-varying and time-varying components of RFI are inevitable for a wide band radar, the non-stationary RFI can not be suppressed effectively by the Current RFI suppression algorithms based on a stationary model. We propose a non-stationary RFI suppression and target echo reconstruction technique based on sparse decomposition to solve the problem in this subject. Considering the sparsity of significant RFI in time-frequency plane，the time-frequency analysis technique is used to research the characteristics of the RFI in UWB SAR. A redundant dictionary which can match the local characteristics of non-stationary RFI well will be constructed to replace the traditional standard orthogonal basis. Then sparse decomposition technique is used to reconstruct RFI. After eliminate the reconstructed RFI, the target echo would have more or less distortion. Therefore it is necessary to utilize prior information, such as the characteristics of transmitting waveform and the sparsity of targets，to reconstruct target echo and improve the imagin

英文关键词： synthetic aperture radar；sparse decomposition；adaptive line enhancer；independent component analysis；matching pursuit