The Army Research Laboratory ultra-wide band testbed radars

In 1988, the Army Research Laboratory (ARL) began a research program to determine the feasibility of bringing emerging technologies together to analyze the problem of seeing through an inhomogeneous medium such as tree/foliage cover or the ground. The results of these studies indicated that continuing work in this area and sponsoring enabling technologies could produce a realizable system, thus leading to an understanding of the physics associated with foliage and ground penetration radar. Based on technology available in 1988, ARL instrumented an ultra-wideband (UWB) synthetic aperture radar (SAR) to collect data supportive of foliage penetration (FOPEN) and ground penetration (OPEN) studies. These programs are aimed at measuring and analyzing the basic phenomenology of impulse radar, specifically the propagation effects of targets, clutter, and targets embedded in clutter. At the time, the system developed at ARL lacked real-time data collection capability. Low transmit-power and the relatively slow data-transfer rates from the A/D converter to the data archiving system resulted in a system that needed many pulses to coherently integrate the power up, produced large amounts of collected data, and require a 50-hour data collection period. Today, by taking advantage of commercial off-the-shelf processors, an advanced A/D converter, a more powerful transmitter, and lessons learned, the authors have designed and assembled a more capable impulse implementation. The paper describes this upgraded radar system and the associated components used in the radar.