Acoustic positioning technology from Sonardyne International Ltd. has been selected by De Beers Marine to assist in the search for diamonds buried off the Namibian and South African coasts. The Ranger 2 GyroUSBL system was supplied through Sonardyne’s South African agents, Underwater Surveys, and is being used to track the position of De Beers Marine’s two Autonomous Underwater Vehicles (AUVs) as they undertake geophysical surveys in water depths up to 200 metres.

Offshore diamond exploration and mining relies heavily on the ability to accurately and efficiently map mineralised targets on the seafloor. De Beers Marine meets this requirement with the use of AUVs fitted with high resolution mapping and imaging sensors. The vehicles’ long mission duration and ability to operate in all weather conditions, enables large areas to be quickly and autonomously surveyed.

For maximum operational flexibility, De Beers Marine operates its AUVs from vessels of opportunity, with all survey equipment containerised so that it can be mobilised in under a day. The ability to quickly transfer acoustic positioning equipment between vessels is an essential operational requirement and was therefore a key factor in the company’s decision to purchase Ranger 2 GyroUSBL.

Ranger 2 tracks the position of a subsea target by precisely measuring the range and bearing from a vessel-mounted transceiver to a transponder installed on the vehicle – a technique known as Ultra-Short BaseLine (USBL). The GyroUSBL acoustic transceiver supplied to De Beers Marine combines a survey grade AHRS (Attitude and Heading Reference System) and a wideband USBL transceiver in a single instrument. It is designed to be installed over-the-side of a vessel on a temporary deployment pole and because GyroUSBL is pre-calibrated, it can be made fully operational in under an hour. These time-saving features enable users to reduce survey costs yet maintain the highest levels of positioning performance.

Quotation

“Reliably knowing the position of our AUVs is of the highest importance to our operations as it guarantees the integrity of the survey data being gathered. The AUVs need to perform multiple dives to the same site in a robust and reliable manner so when Sonardyne recommended Ranger 2 GyroUSBL and we saw its track record, we were impressed. We’re continually seeking out new ways to streamline our survey operations so the time and cost savings associated with GyroUSBL means that we will now be able to move acoustic equipment from vessel to vessel with minimal downtime.”

Paul Nicholson, Geophysical Survey Manager at De Beers Marine

For more information about Ranger 2, click here.