基于级数反演的方位NCS成像算法分析

Analysis of Azimuth NCS Imaging Algorithm Based on Series Reversion

斜视SAR成像时,存在方位空变现象,方位空变减小了方位聚焦深度,可通过方位NCS增大方位聚焦深度。在进行方位NCS时,忽略高次项对驻相点的影响会造成成像精度的降低甚至散焦。采用级数反演方法计算方位NCS的驻相点,提高了驻相点的计算精度,更新了高次变标系数及校正函数。仿真结果表明,采用级数反演计算驻相点后,点目标聚焦效果改善明显,较好地增大了方位聚焦深度。

In squint SAR imaging, there exists of azimuth focus. Azimuth NCS can increase the d pact of high-order terms to the stationary phase po A method of calculating the stationary phase point proposed method improves the stationary phase po azimuth varying phenomenon which reduces the depth ep nt by int of focus. During azimuth NCS, ignoring the im- will result in lower imaging precision even defocus. series reversion in azimuth NCS is proposed. The accuracy by updating the high-order terms coeffi- cients and correction functions. The simulation results show that after adopting the series reversion meth- od for stationary phase point computation, point target focusing effect improves significantly and the depth of azimuth focus increases.