Calibration-free acoustic positioning
CSA International Inc, an environmental survey company working in the Gulf of Mexico, is the first organisation to purchase the new GyroUSBL calibration-free acoustic positioning system from Sonardyne International of Hampshire UK.
The system, which integrates the company’s Lodestar Attitude and Heading Reference System (AHRS) and its latest 6G Ultra-Short Baseline (USBL) transceiver into a single assembly, is claimed to provide significant operational benefits following deep-water ROV trials this summer.
Most USBL positioning systems need to be calibrated for determining precise alignment offsets between an acoustic transceiver and a vessel’s own attitude sensors, a time consuming exercise involving specific manoeuvres over several hours for acquisition and processing of relevant data.
With Lodestar GyroUSBL, however, any sensor offsets are said to be largely removed by tight mechanical coupling of its two elements and subsequent calibration at Sonardyne’s factory.
The system supplied to CSA International formed part of a Sonardyne Ranger 2 positioning system installed on an over the side deployment pole fitted to an offshore supply vessel, HOS Sweetwater. It was put to the test by way of tracking the descent of an ROV to a depth of 1,478m.
