基于转台的中场ISAR成像技术研究

Investigation on techniques of middle-field ISAR imaging based on rotator mode

在中场区通过对相位弯曲补偿进行微波成像与远场成像效果相当,且能大大降低对测试距离的要求,所以具有很强的工程应用价值。基于经典的转台成像模型,本文提出球面波聚焦卷积积分法和中场滤波-逆投影算法,实现了中场区目标的微波成像。球面波聚焦卷积积分法能实现360°范围的二维成像,且运算速度快,适用于各向同性目标,中场滤波-逆投影算法针对小转角范围内对目标进行精密的二维成像,适用于各种复杂目标。仿真和实验结果表明,这两种算法的有效性。

The effect of middle-field ISAR imaging by mending curved phase front is as same as the far-field imaging, but the former can greatly save the testing distance, so it is of great engineering application values. Based on classic rotator mode, spherical wave focus integral arithmetic and middle-field CT arithmetic as two new imaging methods are presented in this paper, which realized the microwave imaging of target in middle-field. Spherical wave focus integral arithmetic can realize the imaging in 360 degree,has fast operation speed at the same time,which is especially suitable for isotropy target. Middle-field CT arithmetic can excellently get 2-D imaging with small aperture angle, and can be applied into all kinds of complex target. The simulation and experiment result proved the affectivity of the arithmetic.