含旋转部件的ISAR目标分离式成像

Separately Imaging for ISAR Target with Rotational Components

  • 摘要: 随着雷达成像分辨能力的不断提升,转台模型所引起的二维距离走动已经影响到高分辨ISAR成像质量。同时,雷达目标物上部件的微动也变得不可忽略。因此,针对含旋转部件的目标的ISAR回波,本文提出了一种基于回波分离处理的精细化成像流程。该流程通过对目标物的刚体、部件回波进行分离,有序地对来自转台模型的二阶、一阶距离走动进行补偿,并获得旋转运动参数估计。其后,再对两种回波分别用与之相适的方法进行成像,完成对整个目标物图像的精细化处理。仿真和实测数据的处理结果验证了该流程的有效性。

     

    Abstract: With the development of radar technique, radar imaging tends to be more and more clear, delicate and accurate. And as the resolution of radar imaging is growing, the two-dimension range migration caused by turntable model has influenced the effect of high-resolution ISAR imaging. What’s more, the component’s micro-motion according to target also can’t be ignored. Therefore, this paper puts forward a processing flow, which is based on processing two kinds of echoes separately, in order to image the target with rotational components delicately. First, this flow separates echoes from target’s body and rotational components by using Radon-Wigner transform with CLEAN technique. The motion parameters of turntable model could be estimated in the meantime. Then, the second-order range migration, which is resulted from turntable model, should be compensated for both echoes by adopting space-time analysis. After that, for body’s echo, Keystone transform is applied to compensate first-order migration caused by turntable model to get a focused figure. Meanwhile, inverse Radon transform is employed on the envelope curve or time-frequency distribution of components’ echoes so as to gain fine images of rotational parts. Experimental results using both simulated and measured data confirm the validity of the proposed flow.

     

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