基于自适应动量估计优化器与空变最小熵准则的SAR图像船舶目标自聚焦算法

A Novel Autofocus Algorithm for Ship Targets in SAR Images Based on the Adaptive Momentum Estimation Optimizer and Space-variant Minimum Entropy Criteria

在SAR散焦船舶图像中,部分船舶目标的散焦现象具有沿距离向空变的特性。针对此类散焦船舶目标,该文提出了一种基于自适应动量估计优化器与空变最小熵准则的SAR图像船舶目标自聚焦算法,该算法直接对复图像进行处理,可以实现对任意阶次相位误差的补偿。在仿真数据和GF-3数据上的实验结果表明,所提算法可以有效地实现SAR图像空变散焦船舶目标自聚焦,聚焦后的船舶图像在图像熵与对比度上都有所改善,且算法聚焦速度有很大提升。

In SAR defocused ship images,the defocusing phenomenon of some ship targets is space-variant along the distance.In this context,a novel autofocus algorithm combining the adaptive momentum estimation optimizer and space-variant minimum entropy criteria is proposed to address these defocused ship targets.The algorithm can directly process complex images and compensate for any order phase errors.The effectiveness of the proposed method is proved by the experimental results on the simulation data and GF-3 data.Moreover,the entropy and contrast of the refocused image have been improved,and the focusing speed of the algorithm has been greatly enhanced.