 Detection of mines, both on the active battlefield and in reconstituting nations with unexploded ordnance (UXO) remains a critical problem.As part of the Strategic Environmental Research and Development Program (SERDP), the U.S. Army Research Laboratory (ARL), starting in 1997, began an effort to collect, under extremely controlled condition, a library of UXO signatures.As part of a larger research initiative to create technology that could detect targets buried or hidden by foliage, the U.S. Army Research Laboratory (ARL) developed multiple UWB SAR radar systems with promising object-penetration capabilities.