Unmanned Systems Technology 028 | ecoSUB Robotics AUVs I ECUs focus I Space vehicles insight I AMZ Driverless gotthard I InterDrone 2019 report I ATI WAM 167-BB I Video systems focus I Aerdron HL4 Herculift

10 Platform one U-blox has unveiled its newest GNSS receiver, the M9, which has been designed with autonomous aerial and automotive applications in challenging locations in mind (writes Rory Jackson). The applications include heavy-lift and transportation through urban canyons that are prone to large multi-path errors, or near telecoms infrastructure or other structures that produce strong EM emissions. It has security configurations aimed at protecting against spoofing and jamming, along with new features for mitigating RF interference. The M9 is configured to track L1 signals from GPS, GLONASS, BeiDou and Galileo concurrently, to provide a wider range of satellites and ensure that enough of them are visible to the host vehicle’s GNSS antenna amid skyscrapers and other potential obstacles. It improves on its predecessor, the three-constellation M8. “Having more satellites visible enables the receiver to use the positioning data from the ‘best’ signals,” said Bernd Heidtmann, product manager at U-blox. “For example, that can mean the one with the strongest signal in terms of received power output, but an algorithm weighs many other parameters as well to determine which is best.” The new system has a static accuracy of up to 2 m (or up to 1.5 m with SBAS correction), compared with static accuracies of up to 2.5 m or to 2 m with SBAS on the M8. To further aid positioning accuracy for UAVs, the M9 has a position update rate of 25 Hz (a 7 Hz improvement over the M8), a capability that is attributed to the bigger RAM on the new UBX-M9140 GNSS chip powering the M9 (compared with the M8’s chip). The UBX-M9140 is in a quad flat no- leads package measuring 5 x 5 mm, mounted on U-blox’s NEO-M9N board module, which measures 12.2 x 16 mm. It uses the same pin-out configuration as the company’s previous NEO modules. The M9 has three RF filters integrated into its hardware and firmware to lessen the likelihood of performance degradation through RF interference, whether that be from jamming, nearby transmissions or emissions from other components next to (or on) the GNSS circuit board. For reducing out-of-band RF interference, a surface acoustic wave filter is installed between the GNSS antenna input and a low-noise amplifier on the NEO-M9N. Inside the UBX-M9140, two more filters are installed, one of which is a static notch filter for blocking in-band interference from signals registering at a specific frequency. This and the SAW are carryovers from U-blox’s previous GNSS receivers. The other filter is an ‘adaptive notch’ type, a new feature being introduced with the M9. It has been developed to lock on to and reject in-band signals that are varying in their exact frequency. LTE signals for example can behave in this manner, and will become a more widespread source of interference over time. “We’ve been receiving increasing requests for new security features from end-users, who are particularly concerned about attacks on their positioning and correction solutions via the internet,” Heidtmann said. “Spoofing is what people are most concerned about – a consumer tablet or laptop is enough to trick a GNSS into reporting the wrong time or position to an autopilot. “We’ve therefore developed some proprietary algorithms for detecting spoofing with our firmware, and we’ve also put in protections for the firmware transfer process to prevent hostile actors from modifying the firmware as its updates are installed onto the M9. Further specifications and data on the M9 and its components will be released by U-blox at the end of this October. Communications GNSS for problem areas October/November 2019 | Unmanned Systems Technology The UBX-M9140 is configured to receive signals from the four main GNSS constellations, and give three levels of RF filtering to mitigate interference