Sonardyne has been supplying acoustic position reference systems for dynamically positioned vessels for 24 years. The very first vessel to be equipped with an Ultra-Short BaseLine system was the Huafa in 1993, supporting subsea operations in the South China Sea. To mark the occasion, Sonardyne takes an in-depth look at Ranger 2, the company’s current generation USBL, highlighting the features that set it apart from its rivals and the technologies behind it that enable it to deliver the best position.
1 – Accuracy and Precision
Not all USBLs are the same
USBL systems measure the range and bearing from a vessel-mounted acoustic transceiver to a transponder deployed subsea, but not all USBLs do it with accuracy and precision.
Ranger 2 is proven to deliver both regardless of the water depth, vessel type or operating range. For DP, these are critical factors when considering the capabilities of an acoustic position reference system where the objective is to keep the vessel as stationary as possible.
Ranger’s accurate in that each range and bearing measurement to the reference transponder is close to the true value and precise in that there is little to no difference in the result of each measurement. The high quality and robust output from Ranger 2 ensures that DP desks are able to assign a high level of weighting to the acoustics, aiding vessel station keeping in all conditions.
2 – Standard or Pro?
A simple choice
It is crucial to consider acoustic reference system requirements in their own right rather than merely as a sensor supplied as part of a larger vessel scope of supply. This approach will ensure the equipment being specified is capable of meeting the vessel’s operational requirements. After that, deciding which Ranger 2 system is right for you is a simple one; Standard or Pro.
In Standard configuration, Ranger 2 is able to provide a DP position update at one second intervals in any water depth. Simultaneously, multiple subsea targets can be tracked to beyond 6,000 metres range. Ranger 2 Standard satisfies the operational requirements of nearly all users.
In Pro configuration, Ranger 2 adds support for Long and Ultra-Short BaseLine (LUSBL) acoustic positioning. The technique combines the performance from a Long BaseLine (LBL) network of transponders deployed on the seabed, where accuracy is virtually independent of water depth, with the flexibility of USBL. As a result, a Ranger 2 system’s configuration is scalable to efficiently meet the requirements of all applications and water depths.
The robustness and stability of the positioning solution has made Sonardyne LUSBL systems the primary DP reference on many vessel installations, particularly in fields off Brazil and West Africa.
3 – 6G and Wideband
The technology behind Ranger 2
Ranger 2 builds on the simplicity and reliability of Sonardyne’s original Ranger system but adds support for 6G (Sixth Generation) acoustic instruments and Wideband 2 signal architecture. These exclusive technologies are proven to deliver robust performance, low cost of ownership, faster subsea operations and hardware that is easier to set up and operate.
4 – Dual Redundancy
When failure is not an option
Due the critical nature of the subsea operations they conduct, vessels rated as Class 2 and 3 must have fully redundant DP systems and redundant position reference sensors.
In a Dual Redundant Ranger 2 setup, all vessel-mounted hardware (transceiver, acoustic processor and navigation PC) is duplicated and interconnected so that failure in any one element will not affect the system’s ability to provide a continuous position output to the DP desk.
5 – DP-INS
Independency you can rely on
DP vessels have traditionally relied exclusively on GPS and acoustics as their two primary types of position reference but there is a recognised need amongst operators to complement these references with an alternative technology that would allow safe rejection of position errors in one of the other two reference types. To meet this requirement, Sonardyne now has an inertial navigation-based sensor called DP-INS.
DP-INS combines the complementary characteristics of Wideband 2 acoustic signal technology with high integrity inertial measurements. The resulting output is resilient to acoustic disruptions and completely independent from GPS. The need for only occasional acoustic aiding provides additional operational cost saving benefits by extending transponder life and reducing maintenance operations.
Although optimised for Ranger 2, DP-INS can be used with other acoustic positioning systems.
6 – DP Telegrams
Ranger talks everyone’s language
GE, Kongsberg, Marine Technologies, Navis, Rolls- Royce or Transas. Whichever DP system you currently use or are considering for your new build, Ranger 2 and DP-INS are engineered to be compatible with all of them.
A wide range of industry output DP telegrams are supported as standard including; $GGA, $SSB, HPR300P & 309, HPR418 & BCD, ATS Ascii, Trackpoint II, PSONALL, PSONMEAS, PSONUSBL, PSONDP. And, in case your DP speaks another language, Ranger 2’s and DP-INS’ output can be custom configured to meet your requirements.
7 – Software
Easy to learn. Easy to use
The Ranger 2 user interface was developed in close co- co-operation and feedback from DPOs. It is both easy and intuitive to use, ensuring users quickly gain confidence in using it. Exploring the menus reveals an extensive array of diagnostic and setup tools to assess and fine tune the performance of the system. Included as standard are real-time acoustic quality indicators, noise analysis and signal travel time displays.
8 – High Performance Transceiver
A perfect match for your vessel
HPT is a family of high performance, vessel-mounted acoustic transceivers engineered to deliver unrivalled USBL positioning on any vessel. Different transducer array designs are available to provide optimum performance for any given operational scenario including shallow, ultra deep and high noise.
The flat design of the hydrophone array is one of the secrets of its superior performance. Unlike spherical arrays that require hundreds of elements to transmit and receive, HPT uses just a small number of elements with carefully designed ‘null’ points that ignore noise interference.
With a flat array, the effective baseline over which phase is measured is increased, so providing better precision. The difference can be likened to the variation in performance between an SLR camera lens and a camera phone lens.
9 – HPT
More than just a USBL transceiver
HPT’s capabilities extend far beyond its role as a USBL transceiver. As standard it supports LBL and LUSBL operations and can be used as a high speed modem for data retrieval applications. HPTs can even be supplied with an integrated Lodestar attitude heading reference system, eliminating the need for a system calibration. See point 12 ‘GyroUSBL. The ultimate USBL transceiver.’
10 – Through-hull or Through-tube
How will you deploy yours?
The performance obtainable from any USBL is hugely dependent upon how the transceiver is deployed. With over forty years of experience in the deployment of transponders and transceivers, Sonardyne has the experience to achieve the optimum solution.
Sonardyne’s through-hull hydraulic machine is recommended for permanent installations. It features an extremely stiff pole to eliminate flexing and vibration caused by DP thrusters and can be controlled directly from the DP desk. For large vessels such as heavy lift crane barges, a through-tube machine provides the solution. For temporary installations, a high quality portable over-the-side deployment system is available. It’s practical to transport and install on any vessel whilst still enabling survey grade quality USBL system performance.
11 – Optimised Ranger 2
Get the best from the best
The positioning accuracy obtainable from Ranger 2 can be improved by interfacing the system directly into Lodestar, Sonardyne’s premium quality Attitude and Heading Reference System (AHRS), a configuration known as Optimised Ranger 2. In Optimised Ranger 2, the Lodestar is co-located with the vessel’s HPT transceiver so that raw USBL range and bearing data can be simultaneously processed with the Lodestar’s attitude data. This achieves a tightly integrated solution that enables a system accuracy of 0.1% of slant range. An Optimised Ranger 2 is therefore able to meet the positioning specifications of subsea projects that previously may have required the use of alternative acoustic positioning techniques.
12 – GyroUSBL
The ultimate USBL transceiver
Conventional USBL transceivers need calibration before use. The process determines the precise mis-alignments and offsets between the acoustic transceiver and the vessel’s own attitude and heading sensor. However, calibration can be a time consuming exercise as it ideally requires deep water and can involve many hours of vessel manoeuvres.
To eliminate this process and for greater efficiency, Sonardyne has developed a pre-calibrated transceiver called GyroUSBL. The unit integrates a Lodestar AHRS and HPT into a single unit and with the Lodestar in fixed mechanical alignment to the HPT’s acoustic array, its precise alignment can be ‘zeroed’ at the factory.
This means GyroUSBL and Ranger 2 can be quickly mobilised without the need for a lengthy calibration. A simple ‘spin-test’ overhead an existing transponder, can be carried out en-route as a client accuracy verification survey.
13 – Upgrading
Out with the old, in with the new
Whether because of performance issues or product obsolescence, when the time comes to upgrade a vessel’s DP acoustic reference to Ranger 2, Sonardyne makes the process as seamless and low risk as possible.
The company’s project teams are highly experienced in replacing systems from all major manufacturers and in nearly all cases, are able to re-use existing deployment machines and gate valves to minimise costs and vessel downtime.
Through careful planning with clients, shipyards and operators, a complete system can be replaced in under 24 hours. Equally for new builds, Sonardyne is able to advise shipyards on where best to locate vessel hardware to ensure optimum system performance.
Support and Training
When you invest in Sonardyne, you know that in five years time, your equipment won’t be out of date. Sonardyne’s policy is to support and supply spares for current and previous generation products, meaning that at present 5th and 6th generations are supported throughout, from planning, consultancy and custom engineering through to delivery, commissioning and operator training.
As products near the end of their life, Sonardyne works closely with clients to ensure they have a cost-effective upgrade path, keeping positioning technology current throughout the lifespan of the vessel. Advice and support from Sonardyne is available around the clock to maintain, advise and upgrade. It’s all part of the service.
Why Invest in Sonardyne and Ranger 2 USBL
- The highest performing USBL for all applications
- Global track record and on all types of vessels
- Low risk;we understand your operational needs
- Advance features included as standard;no hidden costs
- Global support, wherever and whenever you need it
- Operational in all water from shallow to ultra deep
- Any USBL system can be upgraded to improve your capability
- Software and hardware that is easy to learn and reliable