Unmanned Systems Technology 027 l Hummingbird XRP l Gimbals l UAVs insight l AUVSI report part 2 l O’Neill Power Systems NorEaster l Kratos Defense ATMA l Performance Monitoring l Kongsberg Maritime Sounder

58 touchscreen monitors and a range of control interface options including standard keyboard, multiple joysticks and dials. The larger size of the G2Nav (compared with the company’s usual smaller, tablet-sized GCSs) allows higher levels of processing power and more powerful data links to be integrated into the system, for users looking to conduct missions at high altitudes with long endurances and live HD video outputs. Tallysman showcased a major extension of its lightweight GNSS and Iridium antenna portfolio, debuting the first three models of a high-performance line of housed helical antennas; they are the lightest line of antennas to be released by the company. They are the HC600, an 18 g passive Iridium antenna; the HC871, a 25 g dual- band active GNSS antenna supporting GPS/QZSS L1/L2, GLONASS G1/G2, Galileo E1, and BeiDou B1; and the HC872, a 36 g dual-band active GNSS antenna, supporting the same frequency coverage as the HC871, as well as L-band correction services. “We’ve designed our helical line of antennas to achieve an axial ratio of below 1 dB, and in many cases below 0.5 dB,” said Mohamed Emara. “Furthermore, with our pre-filtering features, we mitigate interfering signals such as wi-fi on 2.4 GHz, 4G LTE at 700 MHz, and other near-frequency signals that can cause problems for UAV operations in busy, urban areas.” Avanti Unmanned Systems has developed a range of reciprocating UAV engines, from 32 to 180 cc, and at the show it displayed its 180 cc two-stroke, two-cylinder product. “The 180 cc engine has been developed to fulfil a range of UAV propulsion envelopes and needs,” said Chris Goodman. “It produces up to 18.5 hp, and we have built an alternator/ starter into it that can generate 400-600 W of spare power. “We’re seeing a lot of interest in hybridisation as well, so we offer an option for a larger alternator that can generate power in the 3-4 kW range.” The standard alternator/starter weighs about 870.5 g, and the starter is powered by an internal lithium-polymer battery (typically a 24-45 V, 6S or 7S system). The crankcase is machined from an aluminium 6061-T6 billet, rather than cast, which makes the crankcase stronger and much less prone to cracking, according to the company. While displacing 180 cc (with a bore and stroke of 53 and 41 mm respectively), the engine’s cylinders also have a compression ratio of 8:1. The engine idles at 1300 rpm and runs up to 7200 rpm. It takes 93 octane fuel, with a 1:40-1:50 ratio of two-stroke oil and gasoline in the fuel mixture, and weighs a total of 4.752 kg. Septentrio showcased its ‘mosaic’ GNSS module, which is designed as the company’s smallest form factor satellite navigation solution. “It measures 31 x 31 mm, and integrates the same capabilities as the rest of our GNSS receivers, including RTK processing and our AIM+ interference mitigation algorithm,” said Francesca Clemente. “Such small size and light weight is critical for UAVs, and is also useful for automotive systems as they are equipped with more and more sensors for autonomy and redundant navigation.” The Mosaic receiver weighs 7 g and updates at rates of up to 100 Hz. It also integrates Septentrio’s IONO+ algorithms to correct for ionospheric disturbances of received satellite data, as well as its LOCK+ algorithm that enables tracking to be maintained amid rapid signal changes, for example those caused by mechanical vibrations or shocks, earthquakes or ionospheric scintillations. That enables prolonged operations in August/September 2019 | Unmanned Systems Technology A Tallysman HC Iridium antenna 180 cc engine from Avanti Unmanned Systems Septentrio’s ‘mosaic’ GNSS module Show report | AUVSI Xponential 2019