用于空间转换的巴克ISAR信号形成与图像重构

摘要

讨论了基于巴克相位编码调制发射信号和三维逆合成孔径雷达(ISAR)结构的ISAR概念.ISAR信号形成可理解为3D图像功能向2D信号功能的非对称空间转换,而图像重构被认为是2D信号功能向2D图像功能(重构的图像)的空间逆转换.经证实,这种图像重构算法由距离压缩互相关、方位压缩傅里叶变换(被认为是第一级运动补偿)和更高级相位校正组成(被认为是更高级运动补偿,通称自聚焦程序).引入熵作为图像成本功能,以评估相位校正功能的多项式系数.通过数值实验以验证ISAR的几何结构,信号形成模式和图像重构算法.%Inverse synthetic aperture radar(ISAR) concept,based on the Barker's phase code modulated emitted signal and three dimensional geometry of the ISAR scenario is developed.ISAR signal formation is interpreted as an asymmetric spatial transform of a 3-D image function into a two-dimensional(2-D) signal function,while the image reconstruction is considered as an inverse spatial transform of the 2-D signal function into a 2 D image function(reconstructed image).It is proven that the image reconstruction algorithm consists of cross-correlation for range compression,Fourier transform for azimuth compression,interpreted as motion compensation of first order,and higher order phase correction,interpreted as motion compensation of higher order known as an autofocus procedure.Entropy is introduced as an image cost function to evaluate the polynomial coefficient of the phase correction function.To verify the ISAR geometry,model of signal formation and image reconstruction algorithm a numerical experiment is carried out.