Foliage PENetration Reconnaissance, Surveillance, Tracking and Engagement Radar (FORESTER); the DARPA-U.S. Army Affordable Adaptive Conformal ESA Radar; and the All-Terrain Radar for Tactical Exploitation of MTI and Imaging Surveillance (ARTEMIS) of the U.S. Army’s Communication-Electronics Research Development and Engineering Center. EO systems include the U.S. Air Force Angel Fire wide-area persistent FMV system; the US Army Constant Hawk ISR payload; the U.S. Air Force multitelescope, Gorgon Stare WAMI system for the Reaper; and the DARPA-sponsored Autonomous Real-Time Ground Ubiquitous Surveillance Imaging System for use on the YMQ-18A (Boeing A-160 Hummingbird). Each of these sensor payloads is currently suitable for larger, Class IV UASs—like the Reaper, YMQ-18A, or Global Hawk—or for light surveillance aircraft, but concerns over best TCPED strategies remain because enormous quantities of data are generated by each of the various sensors. Moreover, these payloads require continued improvement to operate in diverse threat environments. The assessment of yellow in Table G-3 was arrived at as a result of substantial concern over a suitable deployment strategy for the squad. A sensor package scaled for a lower tier UAV and close-range operation might be a good idea. TCPED—especially processing/exploitation and dissemination aspects—and autonomous and clandestine operation remain areas for further evaluation and development.
Through-the-wall surveillance technology has been another area of focus for DoD investment. Key efforts include the DARPA RadarScope, DARPA’s Visibuilding program, the U.S. Army Sense-Through-The-Wall program, and the U.S. Navy Transparent Urban Structures (TUS) effort. Visibuilding and TUS both had reach-goals that included mapping the interior of specific buildings of interest to identify hallways, stairwells, hidden rooms, weapons caches, etc. The RadarScope is a weapon-mounted radar used to detect motion and heartbeats behind a wall. The U.S. Army Sense-Through-The-Wall blended features of Visibuilding, TUS, and the RadarScope. With the exception of the RadarScope, the sensor CONOPS and deployment of through-the-wall systems remain a concern. One possible strategy is to deploy the sensor on a tripod; UAS and tractor-trailer deployments have also been considered. In the deployment, operator motion—leading to false detections and obscuring potential targets—is a critical concern. This technology is given a yellow rating since further development, scaling, and CONOPs best meeting the squad’s needs are needed.
Obscured target detection has been the focus of a number of developmental efforts, including the aforementioned FORESTER and ARTEMIS programs, the U.S. Air Force Tanks Under Trees effort, and the DARPA-U.S. Army Jigsaw program, to name a few. Jigsaw is a three-dimensional ladar that maps beneath the foliage by moving through a large angle and poking through holes in the tree canopy. Additionally, ground-penetrating radar systems are commercially available and regularly used by the electrical utilities industry. This technology receives a red assessment, since radar is the preferred and most robust technology that nonetheless must operate at low frequency, generally in the UHF (450 MHz and below). These low operating frequencies require physically large