Forward-looking ground-penetrating radar. Subsurface target imaging and detection. A review

Detection of shallow-buried, in-road threats using a forward-looking (FL) ground-penetrating radar (GPR) system has attracted significant research interest in the last decade. An FL-GPR mounted on a moving platform can provide standoff target detection and imaging. This enables real-time sensing and situation awareness over large ground areas. The main challenge facing this sensing technology is high false-alarm rates due to scattering arising from air–ground interface roughness and subsurface clutter. In this article, we present a comprehensive review of the state-of-the-art techniques that address the unique challenges associated with FL-GPR technology. Specifically, we focus on array-based FL-GPR systems and consider both electromagnetic modeling and signal processing for problem formulation and solutions. Image formation methods and target detection approaches are discussed, highlighting their offerings and shortcomings in providing reliable system performance.