一种基于联合变换相关的PSF估计方法

PSF Evaluation Method Based on Joint Transform Correlation

针对弹体振动引起的星图成像质量退化的问题,提出了一种基于联合变换相关的PSF估计方法。首先,在低帧速CCD相机的曝光时间内,利用高帧速CCD相机拍摄得到振动条件下的连续平移星图序列,将星图序列的相邻帧拼接成联合输入星图;其次,采用联合变换光学相关器作为处理器并引入坐标变换进行相关运算,得到联合输入星图的相对位移矢量,插值处理后估计出模糊星图的连续PSF;最后进行仿真验证,仿真结果表明:联合变换相关法不仅有效克服了仅从单幅模糊星图估计PSF存在的多解问题,还较准确地估计出了由角振动引起的空间变化模糊星图的PSF。

Point Spread Function（PSF）estimation,a method based on joint transform correlation,is put forward to resolve the quality deterioration of the star image imaging resulted from the vibration of missile body.Firstly,within the exposure time of low frame rate CCD camera,a high frame rate CCD camera is used to obtain a continuously translational star image sequence under the condition of vibration;then the consecutive frames of the star image sequence are spliced into a joint input star image.Secondly,joint transform optical correlator is introduced into coordinate transformation as the processor to obtain the relative displacement vector of joint input star image;then interpolation processing is conducted and the consecutive PSF of the fuzzy star image is estimated out.Finally,simulation verification is completed.Results of simulation verification indicate that joint transform correlation method not only effectively overcomes the shortcomings of single fuzzy star image,but also accurately estimates out the PSF of fuzzy star image of spatial transform resulted from angle vibration.