Extended Moving Ship Detection Based on Improved Variance Weighted Information Entropy in ATI-SAR Systems

Ships with a low-signal-to-clutter ratio in sea background are usually difficult to detect due to extensive isolated strong sea clutter. To address the issue, an approach for extended moving ship detection based on improved variance weighted information entropy (VWIE) in along-track interferogram(ATI)-synthetic aperture radar (SAR) systems is proposed. Firstly, the primary potential target pixels are detected by using the ATI detector, followed with the pixel clustering to acquire the images of each potential extended targets. Then, an adaptive spatial filter is designed to suppress sea clutter and optimize the output of those potential targets at the same time. Finally, the improved VWIE with an adaptive window size for each potential extended target is constructed in the filtered image in order to enhance the signal-to-clutter ratio and thus to accurately detect the extended moving ships. Experimental results on dual-channel data-set collected by the satellite TerraSAR-X demonstrate the effectiveness of the proposed approach.