Multipath Exploitation and Suppression for SAR Imaging of Building Interiors: An overview of recent advances

Multipath that involves target scattering is an important phenomenon in synthetic aperture radar (SAR). It is highly pronounced in imaging of building interiors due to the presence of walls, ceilings, and floors surrounding the targets of interest. Multipath attributed to targets is a special type of clutter, which can be either suppressed or exploited. The latter has been the subject of many recent works in the area of SAR imaging and has led to tangible improvements in target detection and localization. In this article, we consider state-of-the-art multipath suppression and exploitation approaches, present their corresponding analytical models, and highlight their respective requirements, assumptions, and offerings. Both conventional and compressive sensing-based approaches are discussed, where the latter assumes the presence of a few behind-the-wall targets.