HALO jumps are used to enter hostile territory undetected when threats to both Airmen and aircraft are expected.
Army's Blimp-Borne Radar System
Video by Maj. Beth Smith U.S. Northern Command -- U.S. Army Joint Land Attack Cruise Missile Defense Elevated Sensor System at the Utah Test and Training Range. Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System (JLENS) January 30, 2014 norad.mil -- JLENS provides elevated persistent, Over-The-Horizon surveillance and fire control quality data against stressing cruise missiles and other air breathing threats and extends engagement ranges for current air defense weapon systems. A JLENS Orbit consists of two systems: a Fire Control Radar (FCR) system and a wide-area Surveillance Radar (SuR) system. Each system is comprised of a 74-meter tethered aerostat, a mobile mooring station, a radar, data and voice communications equipment, control group and associated ground support equipment. JLENS is designed to distribute surveillance, track, and identification data contributing to the Single Integrated Air Picture (SIAP) via Link 16 and the Cooperative Engagement Capability (CEC) networks. Airplanes, drones and cruise missiles pose a significant threat to people, population centers, key infrastructure and our military. That's where JLENS, a blimp-borne radar system made by Raytheon, comes in. http://www.raytheon.com/capabilities/products/jlens/