Ranger USBL is the latest addition to the Sonardyne Ultra-Short Baseline product family and designed for survey and Dynamic Positioning (DP) reference operations. The system provides an operating range of up to 4,000 metres and is ideal for operators with limited experience or who are unlikely to ever undertake advanced USBL positioning and tracking tasks.
An important feature of Ranger USBL is the intuitive user interface means that the system is easy to learn, set-up and operate ensuring that any operator will achieve immediate success.
Two versions of the system are available; Ranger and Ranger Pro. Ranger is designed for DP reference and general target tracking of ROVs and towfish. Up to 4 targets can be tracked simultaneously to ranges of 2,000 metres. The system is compatible with Sonardyne's WSM, DPT and Compatt 5 range of Wideband transponders.
Range Pro is desgined for more advanced survey applications. Incorporating Sonardyne's unique 'ping stacking' technology, the system offers fast position update rates (1 second independent of water detph), tracking of up to 10 targets and full ocean depth operating range (4,000 metres). Range Pro also supports a wide range of industry standard (Sonardyne and non-Sonardyne) MF frequency transponders.
A feature available in both Ranger and Ranger Pro is the ability to undertake Inverted USBL (iUSBL) tracking of towfish over super-long laybacks. With this new method, the transceiver is not installed on the vessel but on the towed body itself which is often several kilometres behind and below the ship. Mounting the transceiver in this way eliminates the need for repeated system calibration, whilst the accuracy and repeatability of the acoustic signals are improved, as the transceiver is located in a low noise, dynamically stable environment.
Ranger USBL systems are comprised of four main components; a rack-mounted or portable Data Fusion Engine, control software, acoustic transceiver and seabed or vehicle mounted transponder/responders.
Data Fusion Engine
The Data Fusion Engine is the heart of the system and is an integrated PC and acoustic processor platform running Ranger software. The unit is designed to meet the complete on-board hardware requirements of any acoustic operation thereby eliminating the need to install and set-up separate systems to meet different acoustic positioning scenarios. As the user’s requirements grow, this ‘one-box’ solution can be upgraded from a Ranger system through to a deep water Fusion USBL system and ultimately, a Fusion LBL system able to undertake complex subsea construction survey tasks.
The Navigation Controller Unit (NCU) is the interface between the acoustic instruments, sensors and the Navigation Computer. In addition to accurately time stamping incoming data from external devices such as GPS, VRU and Gyro, the NCU also provides power and communications for ship-borne acoustic transceivers.
The Navigation Computer is a powerful, purpose-built PC that is used in conjunction with the Navigation Controller Unit. Features include front-mounted USB ports for when access to the rear of the unit is restricted by rack mounting and dedicated monitor power supply.
Ranger USBL Software
Ranger USBL software has been designed to be very easy and intuitive to operate with only basic user training required.
During set-up, the system automatically identifies the type of transceiver connected to the system and configures it accordingly. Multiple attitude, heading and position instruments can be added in a simple I/O ports page which provides feedback on the operation of all inputs and outputs. Instruments are shown in Green if working and Red if not.
Once the system is configured, tracking of transponders can be turned ‘On’ and ’Off’ with a single click. In the event of a power failure, the only action the user needs to take to get the system tracking again is to restore power. The application will start the Navigation Computer andautomatically restart tracking the transponder it was tracking before power was lost.
A key design principle of the User Interface is that an operator can assess the operation of the system at a glance from across the bridge. For example, positions are displayed in either; Green for a good position with update rate, Yellow for a good range but bad USBL signal therefore no position computed, Red for no reply to the interrogation and finally Grey to indicate no information has been received for more than twice the update rate.
For advanced tracking of up to ten targets with the maximum position update rate, Ranger Pro incorporate Sonardyne’s unique ‘ping stacking technology’ originally developed for ultra deep water drilling operations. The technique allows the system to transmit acoustic interrogations to transponders before the last reply was received.
Through ping stacking, Ranger Pro software is able to maintain position update rates of better than one second in any water depth. Ranger software also includes an extensive array of tools to allow the user to optimise the performance of the system. These include utilities to measure acoustic noise, a signal analyser to filter out a specific transponder’s signal and a comms viewer to monitor any NCU or Navigation serial port. To correctly calibrate gyro and VRU offsets and therefore improve positioning accuracy, Sonardyne’s CASIUS calibration tool is also included.
Ranger USBL Transceivers
To optimise tracking of targets at shallow angles, such as long range towfish tracking, a tilt adaptor canbe used with Type 8021 transceiver. The advantage of this is that the target being positioned remains within the optimal operating envelope of the transceiver thereby maintaining positioning performance.
The Type 8024 USBL transceiver is also compatible with Ranger. The unit is a HF frequency transceiver originally designed for use with Sonardyne’s shallow water USBL system, Scout. Now the same transceiver can be used with Ranger topside equipment, therefore providing exisiting Scout users with a cost effective upgrade path to a deep water USBL system.
The 8024 transceiver is compact, lightweight and can be deployedon a rigid, over-the-side pole or through a standard 150mm (6”) gate valve if one is available. To simplify set-up, an integrated motion sensor automatically compensates for the dynamic motion of the vessel. For higher accuracy work, external accuracy work external reference sensors can be used.
Transceiver Deployment Machines
The Dynamic Positioning Transponder (DPT) is a full sized transponder designed specifically for seabed deployment or large target tracking. Available in 3,000 metre rated omni-directional or directional transducers, DPTs are equipped with a simple On/Off switch, rugged spring assisted release mechanism, depth sensors and advanced power and gain controls if required