基于多通道联合自聚焦技术的机载三维SAR运动补偿

Motion Compensation for Airborne 3-D SAR Based on Joint Multi-channel Auto-focusing Technology

机载3维SAR通过天线阵实现3维的分辨,这也导致在分析3维SAR系统的运动误差时,不但要考虑载机的平动误差带来的天线阵整体平移,更要考虑载机转动误差带来的阵元间相对位置变化,因此针对3维SAR的运动误差的分析与传统单通道SAR相比难度更大。该文从平动误差和转动误差导致的斜距变化出发,利用天线阵的线性几何构型,提出基于多通道联合自聚焦技术的运动补偿算法。该算法可同时得到平动和转动误差,从而使载机运动误差得到精确补偿。最后通过仿真实验验证了算法的有效性。

Airborne three-dimensional SAR uses an antenna array to resolve along height. Then, both the translation and the rotation errors of the plane should be considered. The reasons are that the translation error will result in defocusing along track and the rotation error will lead to phase distortion of signals from different channels. Therefore, the analysis of the motion error of 3-D SAR is much more difficult compared to that of traditional single-channel SAR. In this paper, based on joint multi-channel auto-focusing technology, a motion compensation algorithm is proposed, which can be utilized to estimate not only the translation error but also the rotation error with high accuracy. Hence the motion error would be precisely compensated. Finally, simulation results confirm the validity of the proposed algorithm.