Eyes For Drones: Radar And IR Hold Promise

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Just as a combination of radar, transponders and active traffic systems improved flight safety for manned aircraft, the UAS industry may benefit from different twists on the same technology. At the Association for Unmanned Vehicle Systems International show in Orlando this week, General Atomics, the maker of the Predator UAS, explained its novel approach to the so-called sense-and-avoid or detect-and-avoid challenge for drones that will help them blend into the National Airspace System safely.

The company has developed a technology it calls Due Regard Radar that’s capable of actively detecting aircraft as small as ultralights and relaying track data to an operator who can then fly avoidance maneuvers. The system will eventually be capable of autonomous avoidance in the event of loss of link, a not uncommon occurrence in world of remotely piloted aircraft. According to General Atomics’ Satish Krishnan, DRR has been under development since 2011 and will be ready for fielding as soon as next year.

At a technical session at the AUVSI show in Orlando, Krishnan explained that DRR relies on an active electronic scanned antenna (AESA) that requires no mechanical sweep to detect targets and can actually be incorporated into the aircraft structure as a conformal device. The radar is designed to be forward looking, detecting potential threats in front of the aircraft, but not behind it. It uses a fusion engine to combine detection and track data from other sources, including ADS-B and TCAS-type data, to determine which target track is most reliable and then display this for the operator to use as the basis for avoidance. Although the system is intended for UAVs the size of the Predator, Krishnan said it can probably be miniaturized for smaller aircraft. General Atomics has been intensively testing DRR with manned aircraft hosts and targets for the past two years and believes the technology is ready to be rolled out. It’s designed to work equally well with “co-operative” aircraft equipped with ADS-B, transponders or TCAS as well as “un-cooperative” aircraft that have none of those.

Meanwhile, in Europe, a consortium of companies that includes the French avionics manufacturer, Sagem and Rockwell Collins France, has developed a novel UAS sense-and-avoid system that uses both electronic signatures and a forward looking infrared camera for visual detection of targets. The technology is part of a research project called Operational Demonstration of RPAS in the European Airspace (ODREA) and its goal is to show that remotely piloted aircraft can operate safely in controlled airspace and be integrated into a moderately sized commercial airport. Like General Atomics’ DRR, the ODREA RPAS uses a fusion engine to analyze multiple track data to calculate the best avoidance strategies. For more, see the project’s website at Odrea.org.