俯仰向DBF SAR系统通道相位偏差估计算法

Channel phase bias estimation algorithm for the DBF SAR system in elevation

由于俯仰向多通道合成孔径雷达系统通道之间存在相位偏差,因此降低了数字波束形成后雷达图像的性能.为解决上述问题,提出了一种俯仰向通道相位偏差估计算法.该算法首先对相邻通道间的数据进行干涉处理,获得相邻通道之间的复干涉相位图;然后,对复干涉相位进行干涉处理,获得邻近通道干涉相位的差分相位;最后,通过优化图像的最大对比度估计俯仰向通道间的相位偏差.利用车载俯仰向多通道雷达系统获取的数据验证了这种算法的有效性.

Due to the presence of phase bias between channels in elevation of the multichannel Synthetic Aperture Radar （SAR） system, the quality of the （DBF）. In order to solve the problem, this paper multichannel SAR system in elevation. First, the SAR images decreases after Digital Beam-Forming presents a phase bias estimation algorithm for the complex interferograms are obtained by conjugate multiplication of the focused SAR images acquired by the adjacent channels. Then, the differential interferograms are obtained by conjugate multiplication of the adjacent interferograms. Finally, the phase bias between each channel and the reference one are estimated by the maximum sharpness optimization. The proposed algorithm is validated through experimental data acquired by the automobile based multichannel SAR system.