基于方位非均匀插值的高速平台大斜视交错阵SAR改进型omega-k算法

Modified omega-k algorithm for high-speed platform highly-squint staggered SAR based on azimuth non-uniform interpolation.

作者信息

Zeng Hong-Cheng, Chen Jie, Liu Wei, Yang Wei

机构信息

School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.

Electronic and Electronic Engineering Department, University of Sheffield, Sheffield S1-3JD, UK.

出版信息

Sensors (Basel). 2015 Feb 5;15(2):3750-65. doi: 10.3390/s150203750.

DOI:10.3390/s150203750

PMID:25664433

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4367383/

Abstract

In this work, the staggered SAR technique is employed for high-speed platform highly-squint SAR by varying the pulse repetition interval (PRI) as a linear function of range-walk. To focus the staggered SAR data more efficiently, a low-complexity modified Omega-k algorithm is proposed based on a novel method for optimal azimuth non-uniform interpolation, avoiding zero padding in range direction for recovering range cell migration (RCM) and saving in both data storage and computational load. An approximate model on continuous PRI variation with respect to sliding receive-window is employed in the proposed algorithm, leaving a residual phase error only due to the effect of a time-varying Doppler phase caused by staggered SAR. Then, azimuth non-uniform interpolation (ANI) at baseband is carried out to compensate the azimuth non-uniform sampling (ANS) effect resulting from continuous PRI variation, which is further followed by the modified Omega-k algorithm. The proposed algorithm has a significantly lower computational complexity, but with an equally effective imaging performance, as shown in our simulation results.

摘要

在这项工作中，交错合成孔径雷达（SAR）技术被应用于高速平台的高斜视SAR，通过将脉冲重复间隔（PRI）作为距离走动的线性函数进行变化。为了更有效地聚焦交错SAR数据，基于一种新颖的最优方位非均匀插值方法，提出了一种低复杂度的改进型Omega-k算法，避免了在距离方向上进行零填充以恢复距离单元徙动（RCM），并节省了数据存储和计算量。在所提出的算法中采用了关于滑动接收窗口的连续PRI变化的近似模型，仅由于交错SAR引起的时变多普勒相位的影响而留下残余相位误差。然后，在基带进行方位非均匀插值（ANI）以补偿由连续PRI变化导致的方位非均匀采样（ANS）效应，随后进一步采用改进型Omega-k算法。如我们的仿真结果所示，所提出的算法具有显著更低的计算复杂度，但成像性能同样有效。