星载分布式SAR地面动目标精确聚焦的互谱MUSIC法

Cross Spectrum MUSIC Method of Finely Focusing Ground Moving Target on Spaceborne Distributed SAR

该文提出一种新的参数化聚焦算法,该算法采用互谱MUSIC(Cross Spectrum MUSIC,CSMUSIC)技术,能够在星载分布式SAR上得到精确聚焦的地面运动目标图像。首先,利用方位向回波信号的空时特性推导出扩展空时模型(Extended Space-Time Model,ESTM);根据该模型,提出一种基于子空间理论的参数估计方法,通过该方法能够精确地得到的动目标方位向速度,从而得到精确聚焦的图像,该方法比传统的星载SAR动目标聚焦方法具有更高的估计精度和更小的运算量。仿真实验将该方法与传统的动目标聚焦方法进行对比,以证明该文所提方法的上述优势。

A novel parametric focusing algorithm, using the Cross Spectrum MUSIC（CSMUSIC） method, is presented to obtain a finely focused image of ground moving target on spaceborne distributed SAR. By exploiting the space-time property of the azimuth echo signal, an Extended Space-Time Model（ESTM） is firstly introduced. Then on the basis of this model, a parametric estimating method based on subspace theory is presented to estimate the azimuth velocity of moving target and to obtain an image of finely focused. The proposed method has higher precision and lower calculation burden than the conventional algorithms. The simulation results indicate that the proposed method is verified to be more efficient in contrast with the conventional algorithms.