Sonardyne Logo (Sound In Depth)Delivering Trusted Solutions For Subsea Acoustics

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Features & Benefits
Designed for the protection of strategic and high value marine assets including oil and gas installations, LNG tankers, ports and harbours, luxury vessels and naval vessels
Lightweight sonar head weighing 35kg in air
Quick and easy to deploy
Available is three versions to suit detection and tracking requirements; Sentinel, Sentinel RD and Sentinel XF
Advanced detection, classification and tracking filters ensure low false alarm rate
Stand alone or networked operation
Easily operated by non-sonar skilled staff
Sentinel IDS
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Specification upgrades enhance capabilities of Sentinel sonar
Is your underwater perimeter secure?
The new line of defence

Sentinel IDS is the world’s most widely deployed intruder detection sonar, developed to meet the underwater security requirements of private, commercial, government and naval end users.

The system reliably detects, tracks and classifies divers and small underwater vehicles approaching a protected asset from any direction and alerts security personnel to the potential threat. Whether it is protecting a critical infrastructure facility, offshore platform, sea port or super yacht at anchor, Sentinel’s autonomous monitoring capabilities, long range detection and proven low false alarm rates, provide a rapidly deployable, 360° underwater security solution for any application. 

Sentinel takes reliable, long range underwater intruder detection to a new level and since its first introduction in 2006, has been shown to outperform far more expensive and complex technologies. The system is small, lightweight, has a low false alarm rate and once configured, can be left to operate autonomously.

Three variants of Sentinel are available.

The base system, Sentinel, is configured to meet the needs of most commercial and infrastructure facility protection projects. It includes support for networked sonar arrays so that entire waterfronts can be protected and integration with third party C2 (Command and Control) systems. 

Sentinel RD (Rapid Deployment) meets the need for a Portable Diver Detection Sonar (PDDS). Its small system footprint means it can be easily installed in yachts, deployed from small patrol boats or setup to provide underwater security at a temporary site or smaller permanent installation.

Sentinel XF (eXtra Functionality) is available to military and government security agencies as it has both active and passive detection and classification modes and can protect an area of greater than 7 km2 underwater from a single sonar location.

Operational Scenarios

Harbour Entrance / Fixed Point Protection

The reliable detection of underwater targets in the acoustic environment of a harbour is a well known problem. Constant vessel traffic, noise from continually active depth sounders and a complex thermal structure typify this scenario.

Sentinel has been specifically designed to cope with these adverse conditions and is capable of tracking thousands of targets in real time with only genuine threats causing an alarm that the operator or observer need react to.

Mounted in a either a seabed frame looking upwards or on a permanent harbour wall mount looking across the entrance, Sentinel is easy to install and configure for autonomous operation from a remote monitoring station.

Networked Port Installation

Under the International Ship and Port Facility Code (ISPS code) it is vital to ensure protection against foreseeable events. Sentinel has been designed to operate in a stand-alone or networked mode with multiple sonar heads to enable complete protection of assets within the security zone.

The commercial off-the-shelf (COTS) based processing units can facilitate up to 10 sonar heads per command station, offering a cost-effective solution to large area coverage. The overlay will increase the level of domain awareness in an estuary, coastal environment or complex port and can be totally integrated into a central command system with above water surveillance.

Sentinel's unique detection, classification and tracking software has been proven to operate in the harshest environmental conditions including 'brown' water, noisy, shallow, tidal harbours where vessel activity results in a lot of disturbance in the water column.

Asset Protection

Sentinel's compact size and lightweight design make it a practical solution for rapid mobilisation to meet an evolving threat. With minimum storage requirements, the Sentinel system can be carried on board as part of a mobile or expeditionary security unit, providing a secure underwater perimeter for high value assets.

With the sonar head weighing under 30kg it can be deployed over the side of the vessel or from a jetty by one person using only minimal equipment. Sonar processor and command workstation set-up is an equally simple task with the full system typically configured and online in under 30 minutes.

Providing wide area coverage, Sentinel is designed to provide secure underwater perimeters for both military and civilian assets. These include: naval vessels at anchor in overseas ports, cruise liners in harbour and super yachts moored off the coast.

Energy Infrastructure

The threat of insurgency, vandalism or criminal activity is not restricted to ports or military assets. Any oil and gas installation, whether coastal or offshore, is extremely vulnerable to attack from below and represents a significant threat to a region’s energy supplies Sentinel’s open system architecture allows integration of the subsea security zone with conventional terrestrial security systems, including thermal imaging, radar and ground sensing devices.

Sentinel has been developed from the outset with flexible deployment in mind. It can be mounted from a pole based deployment system, suspended from its combined signal and power cable or mounted on the seabed. Considerations such as ease of installation by divers in low visibility have been taken into consideration in the Sentinel system from the very beginning. Sonardyne has a proven track record in deployment systems and can recommend the most appropriate solution.

Sentinel RD
Sentinel RD (Rapid Deployment)
500 metre maximum detect and track range
Simple user interface
Stand alone (not multi-head enabled)

Sentinel RD meets the need for an easy to use and rapidly deployable underwater security solution with detection ranges up to 500 metres. It's small footprint means that it can be easily installed in yachts, deployed from patrol boats or setup to provide temporary security portection as a waterside location. 

Whilst range and functionality are reduced compared to the Sentinel and XF variations, no compromise in the overall system performance has been made, reliable results with Sentinel's renowned low false alarm rates are assured.

Sentinel RD is a single box solution running on just one PC making it the perfect choice for mobile security teams where ultimate detection range is not an issue. With a simplified user interface Sentinel RD can be easily operated by non sonar trained personnel. Whilst range is limited to 500 metres the system will still outperform the majority of 'low cost' diver detection offerings.

With its small footprint Sentinel RD can easily be integrated into command vehicles, ships bridge or security control room.

900 metres maximum detect and track range
Simple user interface
Multi-sonar head enabled allowing wider areas to be protected
Track data output to C2 system

Sentinel is the mainstay of the Sonardyne's diver detection sonar product family, configured to meet the needs of most commercial and infrastructure protection projects.

With consistent tracking of divers out to 900 metres in good acoustic conditions, even in the toughest acoustic environments Sentinel has outperformed other systems in head to head trials.

Sentinel is versatile being available as a self contained, stand alone expeditionary system through to a multi head networked underwater element as part of a fully integrated security package.

Sentinel can be interfaced to a vessels NAVAID package providing the system with vessel position and attitude data ensuring robust and reliable performance for vessel self protection.

Sentinel XF
Sentinel XF (eXtra Functionality)
Fully automated underwater security solution
Up to 1500m range (>7km2 coverage) per sonar head
Active and Passive Detection and Classification
Man portable allows rapid deployment
Advanced software functionality for trained users
Multiple sonar capability enables extended coverage
Advanced software functionality for trained users
Low power enables remote sonar deployment

Sentinel XF is the extended capability variant of the world’s most widely deployed underwater surveillance system, developed to meet the requirements of military and government security agencies. Sentinel is a field proven sonar system that reliably detects, tracks and classifies underwater targets and the potential threat they present. With the introduction of Sentinel XF, and its advanced capabilities, users’ requirements of both autonomous and sonar trained operation are satisfied. Sentinel’s 360° detection capability and flexible installation options provide both a rapid expeditionary and robust permanent deployment solution.

Sentinel takes reliable, long range underwater intruder detection to a new level. The system has been developed to detect and track difficult to find underwater targets. The system is small, lightweight, has a low false alarm rate and, once configured, can be left to operate autonomously.

The flexibility afforded by Sentinel’s small footprint, with its full 360° detection area and network head capability, outperforms far more expensive and complex technologies. For expeditionary installations, the system is flexible and capable of rapid deployment by unskilled operators. For permanent installations, the same subsea hardware can be deployed in many different configurations with full functionality providing the user with complete underwater domain awareness.

The state-of-the-art techniques adopted by Sonardyne, deliver class leading performance which has seen Sentinel adopted as the standard by military, government and private agencies worldwide to protect vessels, strategic waterside infrastructure and VIPs.

Features exclusive to Sentinel XF enable extended range, pseudo Doppler display, A and B scan and zoom functions offering improved functionality for advanced users.

System Components

A Typical System

A typical Sentinel IDS system comprises: a lightweight sonar head, processor platform, command workstation and advanced detection, tracking and classification software.

The Sonardyne Sentinel system has been developed using industry leading techniques, materials and processes. Spares-holding requirements and decreasing future obsolescence issues have been addressed by using COTS based technology.

Sonar Head

The Sentinel sonar head contains the electronics to control the transmitters and digitize and multiplex the received signals from the transducers. The multiplexed data is transmitted to the topside equipment via a copper-based cable for cable lengths up to 100 metres, or via a fiber optic cable for longer lengths.

The sonar head also contains and attitude and heading reference sensor which monitors the orientation of the head and allows the topside processor to automatically compensate for any motion. This enables the system to be suspended by its own cable from moving platforms such as drifting patrol boats or ships on single point moorings. The head is also small enough to be mounted on an unmanned underwater vehicle.

Processor and Software

Pulse compression, beam forming and automatic detection and tracking (ADT) are carried out in two high performance PCs installed in a rugged case. The case also contains the power distribution unit for the sonar head.

The command workstation, a third PC, provides a tactical-style display for the system. This shows the sonar data, track data and alerts overlaid on a chart. If multiple sonar heads are deployed, they are all interfaced to the command workstation via an Ethernet LAN, and the tactical display shows all the sonar coverage in the correct geographical locations on the chart.

The Sentinel software has been written using the latest software techniques, allowing full network connectivity. The command workstation supports track export to an external Command and Control system and can be configured for remote internet access to allow system status reporting from anywhere in the world.


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