Unmanned Systems Technology 009 | Ocean Aero Submaran S10 | Simulation and testing | Farnborough report | 3W-110xi b2 TS HFE FI | USVs | Data storage | Eurosatory/UGS 2016 report

17 started us down the path to where we are now with the safety systems group. “There are several technical challenges to making this successful,” Auld explains. “The volume and cost structure are very different from our traditional business – it’s no longer 100,000 units a year that we produce but millions, and the pricing is ten times lower than we are used to. So to tackle the pricing we have had to revisit our products to optimise them for a different set of functions. Guaranteed accuracy “That means we have to look at what will be in the hardware, what in the software, what bells and whistles we have to include. We are not necessarily trying to achieve performance of 1-2 cm, but you do need better than 1 m accuracy all the time, guaranteed. “That meant we had to question the structure of the navigation receiver and how it is designed and manufactured, and even the physical requirements such as a wider temperature range and smaller packaging, so we’ve had to look at how to do it within safety processes such as ISO 26262.” The safety problem can be solved by thinking about it from an integrity perspective, Auld says. For that NovAtel draws on its experience with avionics systems, where it uses protection levels and alert limits to indicate when the system can assure the user that the position information is reliable. Other systems can then take over, or the craft can fall back to a safe mode, perhaps slowing down or circling in the air until integrity is restored. One approach to solving the problem is to use carrier phase-based receiver autonomous integrity monitoring (RAIM). This detects errors or biases in the measurements from the navigation satellite, and generates three sets of data – the location, the estimated accuracy of the position and the trustworthiness of that estimate. RAIM is then coupled with precise point positioning (PPP), another carrier phase system that gives 10-20 cm accuracy by sending error-correction data over a satellite link or cellular network. PPP delivers the RAIM integrity data as well as the correction data, and this is transmitted in a band just lower than the GPS and GLONASS L1 band. “We design the receiver to support that band as well, so we can bring that in as well as the position data to reduce size and cost,” says Auld. “But you can also bring the correction in over cellular, so vehicle-to-vehicle and vehicle-to- infrastructure networks could also be providing the correction data. “We think we have all the pieces to solve this problem safely, and we are looking at how all the elements come Jonathan Auld | In conversation Unmanned Systems Technology | August/September 2016 Jonathan Auld started at NovAtel in 1998 as a GNSS test engineer, and also held the position of programme manager in the aviation team for a number of years. He was director of technology development for several years before a short stint as engineering and technology manager at engineering and UUV company Fugro. In 2013 he returned to NovAtel in the marketing team as director of portfolio management, and most recently took on the role of director of safety-critical systems, in November 2015. NovAtel’s GPS engineering expertise began in the early 1990s with a small group of geomatics engineers. Since then it has evolved into a company of more than 350 employees, with GNSS products manufactured at its headquarters in Calgary, Canada. The company is part of the Hexagon group, based in Stockholm, Sweden, which also includes imaging specialist Leica Geosystems, satellite services providers Veripos and Terrastar, both based in Scotland, as well as US antenna designer Antcom. Jonathan Auld We have to look at what will be in the hardware and what will be in the software... you need better than 1 m accuracy all the time, guaranteed