Issue 45 | Uncrewed Systems Technology Aug/Sept 2022 Tidewie USV Tupan | Performance monitoring | Bayonet 350 | UAVs insight | Xponential 2022 | ULPower UL350i and UL350iHPS | Elroy Air Chaparral | Gimbals | Clogworks Dark Matter

6 Mission-critical info for uncrewed systems professionals Platform one Cambridge Sensoriis has developed a radar architecture that can be used for lightweight, highly sensitive, all-weather sensors on UAVs (writes Nick Flaherty). The architecture is split into two parts – a high-power primary radar that can identify a variety of obstacles and aircraft, and a secondary radar that is much lighter and works specifically with the primary radar. The system operates in the 77 GHz band and was built using COTS devices. The secondary radar weighs 200 g and has a range of up to 1 km. It can be mounted on small UAVs in a swarm or on the ground, with the 1 kg primary unit mounted on a mid-sized UAV. “Several secondary radars could be on the landing pad on a moving ship, for example, or for a vertiport,” said Steve Clark, CEO and founder of Cambridge Sensoriis. This architecture allows a positioning accuracy down to 1 cm to allow an autonomous UAV to land in difficult conditions. The architecture allows the primary radar to focus only on the signals from the secondary, filtering out any reflections from the metal in the ship or a parking structure. “Our primary radar identifies cooperative and non-cooperative UAVs, and we have designed a way for the secondary radar to collaborate with the primary so that it is highly visible, while everything else is not,” said Clark. “The modulation of the primary is designed so that just the secondary is visible. We reinforce the incoming signal from the primary and clean it up. The design of both primary and secondary is to reinforce the primary signal and attenuate the background clutter. “We don’t need to increase the operating bandwidth, and both operate in the same band, which means we can use low-cost, lightweight hardware,” he said. The detection range of the primary is 300 m, and the company is working to extend this to 1 km in a UK-funded Future Flight project. The system is implemented in an FGPA with a radar front-end transceiver and custom beam- forming phased array antenna designed in-house and mounted on a specialist PCB multi-layer stack. The technology is being used in a project called Portal, to develop a scalable capability for deployment in bespoke vertiports or retrofitted installations such as car parks or rooftops. Portal will support vertiports using the same flexible software architecture and with technology from Slink-Tech, Angoka, R4dar Technologies, Auriga Aerospace, Snowdonia Aerospace Centre and the University of Bristol. The Agile Integrated Airspace System (ALIAS) consortium is also using the technology to combine and demonstrate all the necessary elements of an agile and scalable airspace system. The consortium will use terrain and weather maps, and ground and UAV-installed sensing including Sensoriis’ radar, to plan safe UAV journeys and avoid obstacles on the ground or in flight. Consortium partners include Volant Autonomy, DroneCloud, DroneDefence and Sky-Drones. Sensors Two-part radar design August/September 2022 | Uncrewed Systems Technology The Sensoriis architecture allows several secondary radars to be mounted on the landing pad of a moving ship, for example