一种改进匹配滤波器组的方位向速度估计方法

Approach to along-track velocity estimation via improved matched filter banks

高径向速度目标常会引起严重的距离走动,对方位向速度的估计造成较大的影响.针对此问题,提出了一种新的方位向速度估计方法.该方法分析了运动目标在不同域中的信号形式,并发现在二维频域中动目标的方位调制和距离走动体现在同一指数项中,利用该特点在二维频域构造匹配滤波器组估计方位向速度.相比于传统方法,本方法可使方位向速度估计独立于径向速度,并规避了距离走动对方位向速度估计的影响.本方法均适用于机载和星载SAR系统.仿真和实测数据验证了本方法的有效性和稳健性.

Conventional approaches to the along-track velocity estimation are affected by the serious range walk which is induced by the fast across-track velocity.A novel approach via improved matched filter banks is used to solve the aforementioned problem.The proposed approach analyzes the signal expression of moving targets in different domains.In the range frequency and Doppler frequency domain,both the linear frequency modulation in the azimuth direction and the range walk are exhibited in the same exponential term.We can construct filter banks with different along-track velocities in this domain to match the filter.As a result,the along-track velocity can be estimated by searching the peak magnitude.Comparing to conventional approaches,the approach to the along-track velocity estimation is independent of across-track velocity estimation.Moreover,it is not affected by the range walk.The proposed approach can be applied to both airborne and spaceborne SAR systems.The effectiveness and robustness of the proposed approach are demonstrated by simulated and real data.