改进的基于图像评价准则的相位补偿方法

空间目标大都尺寸较小,雷达的回波数据信噪比较低,在目标单元之外往往存在严重的噪声影响,使ISAR成像出现严重的散焦,有时甚至是无法成像,常规的补偿方法不再适用。在分析低信噪比影响的基础上,综合利用不同方法进行相位的估计,提出一种改进的基于图像评价准则的补偿方法对相位进行精确估计,有效地提高成像的聚焦质量。考虑噪声的迭代运算误差,利用信号的相关性,结合相干积累方法,区分噪声与目标单元,大大提高了运算的速度与图像聚焦的质量。实验结果证明了方法的有效性。

Improved Phase Compensation Method Based on Image Evaluation Criteria

Most space targets are of smaller size and the signal to noise ratio（ SNR） of radar echo data is low as well. Serious noise influence often exists outside the target unit,leading to serious defocusing in ISAR imaging,sometimes even failure of imaging.Conventional compensation method is no longer applicable. Based on an analysis of the influence of low signal to noise ratio,different methods are used comprehensively for phase estimation. An improved compensation method based on image evaluation criteria is proposed to realize accurate phase estimation and effectively improve the focusing quality of imaging. Considering the iterative computation error noise,noise and target unit are distinguished by using the correlation of signals and combining with the method of coherent accumulation,and the speed of operation and the quality of image focusing are greatly improved. The experimental results demonstrate the effectiveness of the method.