改进混合积累的单通道机载SAR高径向速度目标检测方法

Improved Hybrid Integration Detection Algorithm of Moving Targets with Fast Radial Velocity Based on Single-channel SAR System

高径向速度目标会产生严重的距离走动并伴随方位失配,方位压缩会使其散焦并弥散在SAR图像中,不易被检测。该文针对高径向速度目标的检测问题,提出一种基于单通道机载SAR的检测方法。该方法通过抽取等效双通道,利用相干对消抑制杂波,并去除动目标的频谱分裂,再运用Dechirp处理和Hough变换积累目标在距离单元内和距离单元间的能量,以获得更大的积累增益。与传统的混合积累方法相比,该方法在抑制杂波的基础上,更好地积累高径向速度目标的能量,从而有效提高该类目标的检测性能。仿真数据和实测数据均验证了该方法的有效性和优越性。

Moving targets are smeared and defocused in SAR images by the series range walk and azimuth mismatch which are caused by the fast radial velocity, so it is difficult to detect them. A novel detection scheme is proposed via the airborne single-channel SAR data. The dual-channel can be retrieved by desampling the airborne SAR data in the azimuth direction. Stationary targets and the spectrum splitting of moving targets can be eliminated by coherent subtracting of the dual-channel data. Moreover, moving targets amplitude are double. Then the Dechirp processing and Hough transform can be applied to accumulate the energy of moving targets. As a result, the integration gain is improved significantly. Comparing with the traditional hybrid integration approach, the proposed scheme can eliminate the clutter and collect the energy of moving targets. The effectiveness and superiority of the proposed scheme are demonstrated by the simulated and real data. K