Ultra Short BaseLine (USBL), sometimes called Super Short Baseline (SSBL), is an underwater positioning system that uses a vessel mounted transceiver to detect the range and bearing to a target using acoustic signals. This range and bearing technique is based on two principles.

The first is that an accurate range can be determined by knowing precisely the time taken for an acoustic signal to travel between the target and the transceiver and the speed at which the signal travelled (sound speed).

The second is that the bearing can be determined by knowing the discreet difference in phase between the reception of the signal at the multiple transducers present in the transceiver. This allows the USBL system to determine a time-phase difference for each transducer and therefore calculate the angle of the arriving signal.

In addition to an acoustic transceiver and in-water transponders, a USBL system is also comprised of several other components, which includes attitude sensors for the accurate determination of vessel pitch, roll and heading (e.g. VRU and Gyrocompass), and for calibration purposes, accurate surface positioning systems, which would typically be a DGPS. The USBL system also features the vessel mounted hardware and software, from which the USBL is controlled, along with the associated cabling and all important deployment pole upon which the transceiver is mounted.

USBL can be used in water depths from less than 10 metres up to several thousands of metres, without the requirement to alter any of the components. As most USBL systems operate in and around the MF frequency spectrum (~18-36KHz), they provide the potential to achieve good ranges to targets, whilst also maintaining a reasonable degree of range resolution, which can be improved when utilising Sonardyne Wideband technology. Once commissioned and calibrated, a USBL system can be simple to operate, requiring little or no operator training.

Ranger 2 is a survey grade Ultra-Short BaseLine (USBL) acoustic positioning system designed for deep water, long range tracking of underwater targets and position referencing for dynamically positioned (DP) vessels. The system calculates the position of a subsea target, for example an ROV, by measuring the range and bearing from a vessel-mounted transceiver to an acoustic transponder fitted to the target. Multiple subsea targets over a wide area and range of water depths can be simultaneously and precisely positioned.

Ranger 2 builds on the simplicity and reliability of Sonardyne’s original Ranger system but adds support for the latest 6G® (Sixth Generation) acoustic instruments and Wideband 2 signal architecture. 6G® systems offer precise acoustic ranging, fast data telemetry and hardware that is easier to set up and operate even in the most challenging subsea operating environments. These features improve the efficiency of survey perations, reduce vessel delays and generate cost savings for owners. 

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Ranger system is a high performance, survey grade Ultra-Short BaseLine (USBL) acoustic positioning system designed for Dynamic Positioning (DP) reference and ROV/towfish tracking operations.

The system incorporates Sonardyne Wideband® acoustic signal technology to enable seamless multi vessel ‘SIMOPS’ capability ensuring no vessel down time. It is recognised as the optimum solution for deep water DP and construction survey as it offers a proven and risk-free solution with the capability to be integrated with Long BaseLine systems to perform tasks such as metrology.

Two versions of Ranger are available allowing operators to choose the system that best suits their needs.

Ranger is designed for DP reference and general target tracking of ROVs and towfish. Up to four targets can be tracked simultaneously to ranges of greater than 6,000 metres*. The system supports a wide range of industry standard telegrams and is compatible with a wide range of transponders including Kongsberg and Sonardyne’s Wideband Sub-Minis, DPTs and advanced Compatt 5.

Ranger-Pro is designed for more advanced survey applications. Incorporating Sonardyne’s unique ‘ping stacking’ technology, the system offers fast position update rates (one second independent of water depth), tracking of up to10 targets and full ocean depth operating range (>6,000 metres). Ranger-Pro also supports many more Sonardyne and non-Sonardyne medium frequency transponders.

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Scout USBL is a complete vessel based underwater positioning system for tracking divers, ROVs and towfish. Compact, portable and easy to install on any vessel, Scout is designed to appeal to users with little or no prior experience of acoustic positioning and those who want to arrive on location, switch on and begin tracking a target immediately.

Scout calculates the position of a subsea target by measuring the range and bearing from a vessel mounted transceiver to a small acoustic transponder fitted to the target; a technique known as Ultra-Short BaseLine (USBL) positioning. USBL positioning is widely used by the offshore and oceanographic industries as it offers high accuracy performance combined with ease of operation. One of its main advantages is that no other in-water acoustic equipment has to be deployed before underwater operations can commence. Only the targets being tracked need to be equipped with a transponder.

With Scout, a support boat can arrive on location, deploy a diver, ROV or towfish and begin tracking it straightaway. This has particular benefits for search and salvage applications when search times are critical.

Three versions of Scout are available; Scout, Scout Plus and Scout-Pro. Scout and Scout Plus are entry level systems that can track one surface vessel and up to six subsea targets at a range of up to 500 metres. Scout-Pro is designed to provide more complex survey support through its fully featured software. It provides greater accuracy, additional tracking capabilities and a 1,000 metre operating range. All three versions of Scout are quick to set up and deploy whilst offering high accuracy and affordability.

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