Unmanned Systems Technology 027 l Hummingbird XRP l Gimbals l UAVs insight l AUVSI report part 2 l O’Neill Power Systems NorEaster l Kratos Defense ATMA l Performance Monitoring l Kongsberg Maritime Sounder

33 Hummingbird XRP | Dossier Federal Communications Commission requirements. However, says Bishop, they can use more powerful transmitters in special circumstances. To date, the Hummingbird has flown with various off- the-shelf radios transmitting from 5 mW to more than 5 W. He says the Hummingbird XRP’s format makes it a good comms platform, as the square aluminium alloy frame that acts as a brace for the landing gear legs – preventing them from splaying out on a hard landing – also serves as the antenna farm. Normally, it is home to omnidirectional antennas covering all the above frequencies. With dish and patch antennas on the ground station and a clear line of sight, this arrangement enables comms ranges of 8-15 miles. For longer line-of-sight ranges – Bishop talks of operating a vehicle at 1000 ft AGL and up to 50 miles away – patch antennas can be mounted on the frame, either at a fixed angle of 45° of depression or on servos so that they can be steered to aim constantly at the ground station’s GPS coordinates. The ground station can also use tracking antennas, taking the GPS feed from the aircraft and putting it into a controller that points a high-gain antenna at it. These are normally dish antennas with gains of between 12 and 20 dBi. Another option for long-range comms involves a second Hummingbird ‘repeater’ fitted with directional high-gain antennas and ‘parked’ at altitude, providing a 300- mile range for up to eight hours. For integration into air traffic, the company is working with suppliers to fit a Mode-S transponder and provide an ADS-B Out capability initially, so that air traffic control facilities and other aircraft with ADS-B equipment will be able to see the UAV on their displays. After that, the plan is to integrate an ADS-B In capability plus sense- and-avoid software that would allow it to fly in congested airspace and autonomously avoid other aircraft. Other emerging technologies, such as audio sensing and low-power radar and long-range Lidar are also being considered for integration. Reference Technologies plans to test these and other capabilities later this summer. Bishop has security as well as safety in mind for the comms and navigation system. He says, “We have designed the vehicle to be as impervious as possible to anti-drone technology that uses extremely high-power RF signals” to jam or overwhelm the internal electronics, which is the purpose behind housing the autopilot in the Faraday cage mentioned earlier. However, the comms antennas will still provide a path into the system for hostile RF signals, so the company is considering patenting what Bishop calls an electronic guillotine device that, on command from the ground once a hostile signal has been detected, will isolate the autopilot and the rest of the control system from interference. Naturally that would mean the vehicle would no longer be able to communicate, so it would have to execute some protocol that would take it to safety autonomously. The Hummingbird comes with a portable multi-screen GCS. Smaller and lighter handheld GCS units are also optionally available. Unmanned Systems Technology | August/September 2019 Sky Power’s SP-180 is mounted in the centre of the duct on carbon fibre support arms (Courtesy of Reference Technologies) Hummingbird XRP Maximum take-off weight: 225 lb Thrust: 400 lb Payload: 30 lb with six-plus hours’ endurance Fuel capacity: 12 gallons Endurance: more than six hours Range: about 300 miles one-way Width: 9 ft Duct diameter: 30 in Outrigger propeller diameter: 27.5 in Engine: 20-28 kW, 180 cc rotary Power available from generator: 13 kW Some key suppliers Airframe: Adam Works Engine: Sky Power Motors, ESCs and propellers: KDE Direct Batteries: Grepow/Tattu Batteries: Panasonic Ballistic parachute: Para Zero Additive manufacturing: iFuzion Datasheet