Unmanned Systems Technology 006 | ECA Inspector Mk2 USV | Antenna systems | Northwest UAV NW-44 | Unmanned ground vehicles | Navigation systems | Lunar X challenge

64 N avigation systems are fundamental to any automated vehicle or platform, and regardless of the type of system they all rely on sensors that require signals from either an external source – whether it be a natural one such as the Earth’s magnetic field or an artificial one such as a radio signal – or self- contained inertial devices. However, every type of sensor has its strengths and weaknesses, and none on its own is sufficient, so engineers have to integrate at least two types of sensor, normally looking for a trade-off between accuracy, size, weight, power consumption and cost to arrive at the optimum solution for any given platform and its mission set. Not by GPS alone While GPS is long established as the primary navigation source, implementing satellite navigation now means integrating modules that can handle signals from multiple global navigation satellite systems (GNSS) and corrections from systems that improve their accuracy, a process known as augmentation. There are currently two fully operational GNSS networks – the US GPS and Russia’s GLONASS – while Europe’s Galileo and China’s BeiDu-2/Compass are scheduled to provide full capability by 2019 and 2020 respectively. Augmentation systems meanwhile exploit GNSS receivers at precisely surveyed positions on the ground to measure errors in the satellite signals, calculate corrections and broadcast them to suitably equipped receivers over Peter Donaldson explains the directions engineers can take in terms of navigation sensor technology and integration Bearing in mind February/March 2016 | Unmanned Systems Technology