方位多通道HRWS SAR多普勒中心稳健估计算法

Robust Doppler centroid estimation method for multichannel HRWS SAR

在方位多通道高分辨宽测绘带合成孔径雷达系统中,为了解决回波多普勒中心估计问题,提出了一种新的多普勒中心稳健估计算法.首先利用方位多通道回波的时域特性,建立了通道相位偏差基于多普勒中心的数学表达式;然后基于通道相位偏差会降低多普勒带宽内信号的事实,以最大化多普勒谱带宽内信号为优化准则,能够有效地估计多普勒中心.实测和仿真数据结果表明,与空间互相关系数法相比,这种算法具有相近的精度,并且在通道空间欠采样时表现更加稳健.

In multichannel high-resolution and wide-swath （HRWS） synthetic aperture radar （SAR） systems, a novel method for the Doppler centroid estimation is proposed. First, by exploiting temporal characteristics of multichannel SAR data, mathematical expressions for channel phase biases on the Doppler centroid are established. Second, based on the fact that phase biases decrease the signals inside the Doppler bandwidth, the Doppler centroid could be estimated by maximizing the energy inside the Doppler bandwidth. Experimental results show that the proposed method has an estimation accuracy similar to that of the spatial cross-correlation coefficient method but has more robustness.