The US Air Force (USAF) has conducted concept evaluation demonstrations of Raytheon’s Ground Based Sense and Avoid (GBSAA) radar at the Gray Butte Airfield, located near Edwards Air Force Base (AFB) in California, US.

The testing was conducted in an effort to demonstrate the radar’s abilities in enabling secure operation of unmanned aerial systems (UAS) in the National Airspace System (NAS), which will become operational in 2015.

The radar utilises a collision avoidance alerting capability that helps prevent mid-air collisions by delivering a series of alerts to the pilot as airborne objects, including balloons or ultra-light approach.

During testing, the pilots and controllers were successful in keeping the UAS safe from intruding airborne objects, whose alerts were provided by Raytheon’s airport surveillance radar model-11 (ASR-11), standard terminal automation replacement system (STARS) system and its surveillance data processor.

Raytheon Network Centric Systems business Air Traffic Management director Joseph Paone said: "Our system properly notifies controllers and pilots of intrusions and accurately shows aircraft altitude, which is important in keeping commercial aircraft, unmanned aerial systems and other hazards safely separated."

Derived from Raytheon’s NAS-certified ASR-11 and the repurposed STARS air traffic control system, the GBSAA is a surveillance and target acquisition radar designed to facilitate the UAS operation in NAS without requirement for a chase plane or ground observer.

The radar also leverages wind farm mitigation technology, which is used to reduce interference caused by the wind turbines near airports.

Raytheon is scheduled to continue GBSAA testing along with the USAF at other installations throughout the US.