Classifying Multichannel UWB SAR Imagery via Tensor Sparsity Learning Techniques

Abstract

Using low-frequency (UHF to L-band) ultrawideband (UWB) synthetic aperture radar (SAR) technology for detecting buried and obscured targets, e.g. bomb or mine, has been successfully demonstrated recently. Despite promising recent progress, a significant open challenge is to distinguish obscured targets from other (natural and manmade) clutter sources in the scene. The problem becomes exacerbated in the presence of noisy responses from rough ground surfaces. In this paper, we present three novel sparsity-driven techniques, which not only exploit the subtle features of raw captured data but also take advantage of the polarization diversity and the aspect angle dependence information from multi-channel SAR data. First, the traditional sparse representation-based classification (SRC) is generalized to exploit shared information of classes and various sparsity structures of tensor coefficients for multichannel data. Corresponding tensor dictionary learning models are consequently proposed to enhance classification accuracy. Lastly, a new tensor sparsity model is proposed to model responses from multiple consecutive looks of objects, which is a unique characteristic of the dataset we consider. Extensive experimental results on a high-fidelity electromagnetic simulated dataset and radar data collected from the U.S. Army Research Laboratory side-looking SAR demonstrate the advantages of proposed tensor sparsity models.

An Overview of Advances in Signal Processing Techniques for Classical and Quantum Wideband Synthetic Apertures

“…Thus, discriminating these targets from confusers or clutter objects in SAR imagery is a highly challenging task in the emerging low-frequency UWB SAR technology used for this application [30]. In general, techniques ranging from dictionary learning to neural networks (NNs) are employed for object classification in this wideband SAR mode [31,32].…”