Why choose it?

Powerful onboard analytics – you can make decisions based on real behaviour, not assumption 

Observer contains SmartCore, our advanced, modular central processing unit. It’s the system’s brain, delivering low power and high performance that supports deployments of up to 10 years, storing raw and analysed at source. 

Apply your own algorithms or use histograms to support fatigue and damage estimation, putting analysis in your control and powering your digital twin. An intuitive, secure, web-based interface streamlines flexible configuration, driving faster decision making and lower operational costs. 

Low and high frequency measurements in one device – no need for different systems 

In-built sensors capture high-frequency motion for vortex induced vibration (VIV), flow-induced vibration (FIV) and structural behaviour monitoring. This combination simplifies and expands your ability to truly understand the behaviour of your infrastructure. 

Observer can operate as a Long BaseLine (LBL) node for highly precise low-frequency motion monitoring such as pipeline creep and movement. It also supports Ultra-Short BaseLine (USBL) positioning, for measuring assets movements in the water column, like riser and umbilical movement. Also allowing data retrieval from a vessel or underwater vehicle. 

Always informed. Always in control – flexible data retrieval

Easily setup, check your configuration and QC your sensor data pre-deployment, and also adjust it acoustically post-deployment, using our intuitive web user interface.  

Set and modify data collection and offloading schedules at any time.  

Our trusted acoustic telemetry provides your seafloor-to-surface communications, in all water depths, even in challenging acoustic environments.  

Compatibility with our 6G ecosystem enables data transfer at up to 9,000 bps to topside transceivers and modems, including our HPT 5000, Modem 6+ and Dunker 6.  

An Ethernet communication link allows larger quantities of data to be harvested directly from subsea control systems or subsea vehicles. 

The solution

Portable and quick to mobilise, our Micro-Ranger 2 USBL system can be used from any waterside location or vessel to track divers, underwater vehicles and equipment. Ideal for using in lochs and challenging water.

It is our smallest ever underwater tracking system. Everything is engineered to fit in one medium-sized carry case. Apart from a laptop to run the software, nothing else is needed and the size is so small, it can be carried on a plane. Perfect for when Aquasky find work outside of Scotland.

For their anchor and mooring inspections, Aquasky attach a Micro-Ranger 2 Nano transponder to their ROV which then travels around the fish farms. A transceiver is mounted on a vessel nearby and acoustic signals between the transponder and transceiver are used to establish the ROVs, and therefore the anchor/moorings, position. This position can be displayed for in-water tracking and output in real world co-ordinates for interfacing into external chart plotting systems for the clients reports.

“We needed an accurate positioning system that continues to work as mooring lengths increase and in a noisy subsea environment. Having used other cheaper systems, the Micro-Ranger 2 is the only one able to consistently supply reliable positions for anchors at the 300m length currently used by the farms we service.“ Steve Barlow, Founder, Aquasky Ltd.

The results

By adding Micro-Ranger 2 to their subsea inspection tool kit, Aquasky Ltd are able to provide a service that has become the industry standard for fish farm inspections. Their use of an ROV means that inspections are quicker, safer and less expensive than traditional diver inspections. Using Micro-Ranger 2 ensures that the ROV never gets lost and provides accurate data which is vital for the inspection reports.

At a glance

• Recommended for long endurance site surveys
• Leave it deployed for six years or more
• Extensive choice of monitoring sensors
• Depth rated to 3,000 m
• Harvest data using a ship, buoy, AUV or USV

AMT has many of the same acoustic functions as Compatt 6, our most popular navigation transponder. It operates in the Medium Frequency (MF) band and is fully Sonardyne Wideband 2 compatible.

Precision pressure, temperature, sound velocity and dual-axis inclinometer sensors are integrated and are intelligently powered up at the requested time and sampling period, providing an ultra-low power platform for up to three years deployment. Sampling regimes can be re-programmed, and recovery of all data can be achieved via the acoustic modem.

The instrument is available with a range of omni and directional transducers, depth ratings and pressure housings dependent on deployment duration and application. Additional external sensors can be easily integrated via the power and communications port.

Life-of-field monitoring

To maintain the integrity of the FSHRs, the Subsea Technology Group from Petrobras’s R&D Centre in Brazil, prepared a specification for PAI of a comprehensive life-of-field subsea monitoring system and contracted BMT Scientific Marine Services as the systems integrator responsible for its delivery.  

BMT has experience in the development of offshore monitoring systems and, following the successful development of a similar system for the Petrobras P·52 platform in Brazil in 2007, BMT again chose to partner with Sonardyne for the positioning and telemetry component of the riser monitoring system. 

The primary requirement for the acoustic instrumentation is to monitor the position of each riser tower and of the turret buoy relative to the seabed. In addition, integrated sensors monitor depth, temperature, inclination and sound speed whilst the integrated modem transfers data from the load and attitude monitoring system on each riser tower to the turret buoy. The system uses Sonardyne Wideband acoustic telemetry to guarantee high speed and reliable data communications for all these tasks. 

Integrity – Measure, command and monitor

To ensure line-of-sight to each riser tower without obstruction by the flexible risers or mooring lines, the turret buoy was equipped with three of our transceivers. The transceivers perform the following multiple functions: 

• Measure ranges directly from themselves to the seabed transponder array in order to provide an accurate position for the turret buoy. 

• Send commands to transponders mounted near the top of each riser tower, instructing them to measure the ranges to the seabed array. The positions of the risers can then be accurately determined.  

• Acquire sensor data from the riser transponders and the seabed array. 

• Send commands to, and recover data from, BMT’s data logger on the risers, fitted with an acoustic modem.

The transponder on the risers and on the seabed are versions of our Autonomous Monitoring Transponders (AMTs) which operate an efficient Wideband command protocol. 

This allows much faster set up of transponder parameters and enables the sensors fitted to the riser transponders to be measured and reported at the same time as the acoustic measurements are made, greatly speeding up the acoustic monitoring cycle. 

In normal operation, data acquisition will be controlled by the topside monitoring system on the FPSO. In the event of a disconnection due to adverse weather or maintenance, the subsea system continues to record data on the turret buoy, which can later be downloaded by the FPSO or another vessel for processing by Petrobras proprietary software.  

The integrity monitoring system provides valuable data about the movement from either vortex-induced vibration or flow-induced vibration and loading on hybrid riser systems from currents and extreme weather events. 

The system demonstrated a growing demand for reliable subsea remote integrity monitoring that has been enabled by the high performance of Sonardyne monitoring and acoustic positioning, data communication systems and subsea strain and motion sensing systems.  

P-52 permanent subsea riser monitoring system

Sonardyne previously supplied the acoustic positioning and data recovery equipment for the single FSHR close to the Petrobras P-52 platform in the Brazilian Roncador field.  

Installed in the Autumn of 2007, a single acoustic transceiver on the platform communicates with the transponders and modem on the risers and with a seabed array of five Sonardyne Compatt 5 transponders.

Because of the large amount of data to recover from the data logger on the risers – over 90 Mbytes in the first six months – our High Data Rate Link (HDRL) was employed to transfer data from the loqqer to the platform. The monitoring system sends strain, motion and position information every four hours. 

This transfers data at the speed of 15,000 bps and is ideal for transferring the large data records to the surface error free and as efficiently as possible.  

Since its commissioning in 2007, the system has provided invaluable data for analysing the movement of the riser tower, allowing confidence in the development of more complex FSHR installations such as in the Cascade and Chinook field. 

(The original version of this article was first published in Sonardyne’s Baseline magazine in 2009. It has been lightly edited for present tense).  

https://www.sonardyne.com/wp-content/uploads/2021/06/baseline_issue_4.pdf