基于多普勒谱估计的多通道SAR盲重构方法

方位信号重构是多通道合成孔径雷达(sythetic aperture radar,SAR)成像过程中关键的一个步骤。文中在现有算法的基础上进行改进和扩展,提出了一种基于多普勒谱结构估计的多通道SAR盲重构方法,能够有效解决模糊分量个数和位置变化,导向矢量未知时信号重构的问题。该方法借助Capon谱估计的思想获得混叠多普勒谱的结构图,然后根据结构图构造导向矢量,实现方位信号无模糊重构。所提出的算法能够尽可能保持多普勒谱的完整性,并抑制多普勒谱边缘的噪声。仿真实验验证了所提算法的有效性。

Unambiguous reconstruction based on Doppler spectral estimation in multichannel SAR imaging

Unambiguous reconstruction is a key step in multichannel synthetic aperture radar (SAR) imaging. An unambiguous reconstruction method based on Doppler spectral estimation is proposed in this paper, which is improved based on the existing algorithms. This method effectively solves the problem of Doppler spectral reconstruction when the number and position of Doppler ambiguities and the steering vectors are unknown. The algorithm proposed obtains the aliased Doppler spectral structure by means of Capon spectral estimation, and then constructs the steering vector to realize the unambiguous reconstruction, which can maintain the integrity of the Doppler spectrum and restrain the noise at the edge of the Doppler spectrum. Simulation results verify the effectiveness of this algorithm.