机载SAR方位空变补偿算法

Airborne SAR Azimuth-variant Compensation Algorithm

当载机的理想航迹与实际航迹存在偏差时,方位上分布不同的目标对应的运动误差历程具有方位空变性。结合传统子孔径频域补偿的思想,提出了一种新的方位空变误差精确补偿方法。该方法采用时域卷积替代频域点乘,在回波方位的慢时间域逐点对不同时刻、不同方位角目标的运动误差进行精确补偿。经仿真和实测数据验证表明,本文所提方法可在精确补偿方位空变误差的同时,能有效克服传统补偿方法存在的方位栅瓣问题,并具有运算复杂度低、利于工程实现的优点。

When there is deviation between ideal track and practical track of aircraft,the motion error course correspondent to different targets distributed in azimuth possesses azimuth-variant.A new azimuth-variant error precise compensation method is presented by combining idea of conventional subaperture compensation in frequency domain.This method employs time domain convolution to substitute frequency domain dot product to perform precise compensation for motion error of target in different azimuth at different time point by point in slow time domain of echo azimuth.The simulated and real measured data verifies that the presented method can be used to overcome azimuth grating lobe issue existed in conventional compensation method and provide advantageous like low operation complexity and benefit for implementation in project while compensating azimuth-variant error precisely.