Unmanned Systems Technology 022 | XOcean XO-450 l Radar systems l Space vehicles insight l Small Robot l BMPower FCPS l Prismatic HALE UAV l InterDrone 2018 show report l UpVision l Navigation systems

34 R adar is becoming an increasingly important technology for airborne as well as ground-based unmanned systems. A focus by developers on reducing costs as well as weight and power, with new transceiver and antenna technologies, is allowing radar to be used in a greater range of platforms than at any time in its history. For ground vehicles, radar sensors have been widely used for advanced driver assistance systems (ADAS) for adaptive cruise control, but this is a very specific application that detects a vehicle ahead and maintains a constant distance. The 77 GHz technology used for it has been rapidly falling in cost as more ADAS systems are installed, but it does not have the bandwidth to allow for collision avoidance and object detection. Radar systems being designed for Levels 4 and 5 autonomy, where unmanned systems can be used on unmarked roads, now aim to provide high-resolution imaging of the environment around the vehicle to provide the levels of object detection required. At the same time, radar has been a standard component in large, remotely piloted airborne platforms, but their use in smaller craft has been limited, largely by the weight of the systems. Reducing their weight and power consumption while maintaining a sufficient sensing range has been a key objective for engineers. Radar systems in airborne platforms have fallen in weight from 5-10 kg to 500 g as a result of new materials, antenna designs and high-frequency transmitters and receivers. They also use high-end digital processors such as field programmable gate arrays (FPGAs) for handling the high-speed operations required for the transmit and receive channels, and the latest graphics processor units (GPUs) for processing the data and tracking objects. Nick Flaherty reports on how emerging radar technologies are helping engineers design sense- and-avoid systems for a growing range of platforms Looking for trouble Metamaterials have enabled radar systems to be used effectively on UAVs (Courtesy of Echodyne) October/November 2018 | Unmanned Systems Technology