The National Oceanography Centre (NOC) will equip the next generation of its Autosub AUV—targeted for under-ice operations—with high-performance hybrid navigation technology from Sonardyne International Ltd.

The new 2,000 meter depth-rated Autosub, also known as Autosub2KUI or A2KUI, is being specifically developed to carry high-performance sensors on the most demanding research missions under polar ice. It will be equipped with Sonardyne’s highest performing SPRINT-Nav inertial navigation system (INS).

​Combining Sonardyne’s SPRINT INS sensor, Syrinx 600 kHz DVL and a high accuracy intelligent pressure sensor into a single housing, SPRINT-Nav is one of the smallest combined inertial navigation instruments on the market, Sonardyne says. Its tight integration of all the raw sensor data at a low level provides subsea vehicles with “unprecedented navigational performance and precision,” Sonardyne says, adding that the SPRINT-Nav has routinely outperformed competing systems in trials conducted for several customers.

The NOC selected the SPRINT-Nav 700, which is equipped with the highest performance available sensors, including Honeywell ring laser gyros and accelerometers. The SPRINT-Nav 700 also has a conservative quoted accuracy of 0.04% 2dRMS (≡0.017% CEP50), Sonardyne says.

“NOC selected SPRINT-Nav 700 to meet its requirements for an advanced dead-reckoning system in a single unit as the backbone of the A2KUI’s navigation system. The capability to plug in other navigation sensors to aid the AUV’s position was also critical and a second upward-looking Syrinx DVL is being incorporated to provide tracking on the underside of the ice,” explains Geraint West, global business manager oceanographic, Sonardyne.  

“A2KUI will also be equipped for acoustic tracking using Sonardyne’s Ranger 2 Ultra-Short BaseLine (USBL) system, which is fitted to the UK research vessels RRS James Cook, RRS Discovery and the new polar research vessel RRS Sir David Attenborough.”