非均匀MIMO-SAR体制基于衰减补偿的快速成像算法

A Fast Imaging Algorithm with Attenuation Compensation for Nonuniform MIMO-SAR

提出了一种非均匀多输入多输出合成孔径雷达(MIMO-SAR)体制下基于衰减补偿的毫米波快速成像算法。在图像重构过程中,该算法通过考虑信号沿空间路径的传播衰减,保留了回波模型中的幅度因子,并对回波中包含不均匀阵列位置信息的幅度项和相位项采用菲涅尔近似,进而将目标图像重构分解为两个子图像的求解问题,最后通过快速傅里叶变换(FFT)以及相干累加等步骤求解出最终的目标图像。仿真分析和实验结果表明所提算法可以在保证快速成像的前提下有效降低信号传播衰减对成像质量造成的损失。

In this paper,an millimeter-wave fast imaging algorithm with attenuation compensation for nonuniform multiple-input multiple-output synthetic aperture radar(MIMO-SAR)is presented.During the process of image reconstruction,the amplitude factor in the echo model is retained for the compensation of signal propagation attenuation,and the convolution operation is performed on the receiving array dimension according to the characteristics of the target echo equation.Next,the Fresnel approximation is applied to the amplitude and phase terms which contain the position information of the nonuniform array,and then the target image reconstruction can be decomposed into two sub-images.Finally,the target image can be solved by fast Fourier transform(FFT)and coherent accumulation steps.Simulation analysis and experimental results show that the proposed algorithm can effectively reduce the loss of image quality caused by signal propagation attenuation on the premise of fast imaging.