SAR Image Recognition Based on Multi-Aspect of Shadow Information

The traditional synthetic aperture radar (SAR) image recognition techniques focus on the electro magnetic (EM) scattering centers, ignoring the important role of the shadow information on the SAR image recognition. It is difficult to classify targets by the shadow information independently, because the shadow shape is dependent on the radar aspect angle, the depression angle and the resolution. Moreover, the shadow shapes of different targets are similar. When the multiple SAR images of one target from different aspects are available, the performance of the target recognition can be improved. Aimed at the problem, a multi-aspect SAR image recognition technique based on the shadow information is developed. It extracts shadow profiles from SAR images, and takes chain codes as the feature vectors of targets. Then, feature vectors on multiple aspects of the same target are combined with feature sequences, and the hidden Markov model (HMM) is applied to the feature sequences for the target recognition. The simulation result shows the effectiveness of the method.