基于逆合成孔径雷达大转角高分辨成像测量方法

High Resolution Imaging Measurement Method for Large Angle Based on Inverse Synthetic Aperture Radar

中文关键词:  逆合成孔径雷达  大转角  Keystone变换  PFA成像算法

英文关键词:ISAR  large angle  Keystone transform  PFA imaging algorithm

中文摘要:

      由于逆合成孔径雷达（Inverse Synthetic Aperture Radar,ISAR）在大转角条件下进行目标成像时，远离成像区中心散射点会发生越分辨单元走动（Migration Through Resolution Cell,MTRC）现象,进而影响了目标测量结果。同时受目标复杂运动特性影响，传统的ISAR成像方法易导致图像模糊与失真。距离-多普勒（Range-Doppler,R-D）算法和传统的包络对齐方法能够有效地降低目标的复杂运动对ISAR图像的影响，但在处理大转角测量成像加速目标和微动方面仍存在局限性。基于此，提出一种ISAR大转角高分辨精细化成像方法，采用将基于高阶Keystone变换的MTRC校正算法和极坐标格式算法（Polar Format Algorithm,PFA）相结合的ISAR目标成像算法。对此ISAR目标成像算法的可靠性进行了对比说明、理论分析、仿真和实验验证。实验结果表明，采用该算法可显著提升ISAR在大转角条件下的目标成像分辨率。

英文摘要:

      Due to the phenomenon of migration through resolution cell(MTRC) of scattering points far from the center of the imaging area during target imaging using inverse synthetic aperture radar（ISAR） under large angle conditions,it can affect the measurement results of the target.Due to the complex motion characteristics of the target,traditional ISAR imaging methods are prone to image blurring and distortion.The range-Doppler(R-D) algorithm and traditional envelope alignment methods can effectively reduce the impact of complex target motion on ISAR images,but there are still limitations in processing large angle measurement imaging acceleration targets and micro movements.Based on this,a large angle high resolution fine imaging method for ISAR is proposed,which adopts an ISAR target imaging algorithm combining the high-order Keystone transform-based MTRC correction algorithm and polar format algorithm(PFA).Comparative explanation,theoretical analysis,simulation,and experimental verification are conducted for the reliability of the ISAR target imaging algorithm.The experimental results show that using this algorithm can significantly improve the target imaging resolution of ISAR under large angle conditions.