Sonardyne International Ltd has announced the completion of a programme of trials that has resulted in several new specification changes to its market-leading Sentinel Intruder Detection Sonar (IDS) system.

Sonar processing and algorithm enhancements have extended the system’s ability to detect, track and classify potential underwater threats up to a class-leading 900 metre range in both shallow water and in complex environmental conditions. Achieving the balance between longer ranges and the higher risk of false alarms has been a key objective for the development team and one which trials data verifies has been achieved.

During the same period, Sonardyne’s new underwater loudhailer ‘Scylla’ has completed final testing and will be delivered to its first customer, an undisclosed European navy, in October 2009. Scylla is claimed to be the world’s first fully integrated non-lethal acoustic countermeasure to be offered with an IDS and operated autonomously within the system user interface. When a diver reaches a pre-set distance from a protected asset, for example a yacht or port entrance, Scylla automatically transmits a pre-recorded audio message through the water to deter the would-be intruder. Should the warning be ignored, further staged-messages can be played. Live messages can also be broadcast allowing security personnel to respond to any situation unfolding before them.

Due to its small size, light weight and ease of set up, Sentinel has proved itself in service as the ideal portable tool for expeditionary use. Sentinel’s operational flexibility has now been further extended with the availability of a new aluminium-bronze housing designed for permanent deployment and also a complete range of modular deployment systems for jetty and shore installations.

The corrosion resistance properties of aluminium-bronze are well known to Sonardyne as the company’s range of vessel-based acoustic positioning transceivers are made of the same material and withstand years of continuous deployment in all waters. Offered as a no-cost option to prospective customers, the first Sentinel sonar with the new housing was shipped to an end-user in September 2009.

“Sentinel had been described as the best expeditionary system on the market and with these upgrades we have also made it the best for permanent installations whilst managing to retain the attributes that have made it the market leader. Very low power requirements and an open architecture approach enable simple integration resulting in dramatically lower infrastructure costs when compared with older generation intruder sonars.”

Dr Graham Brown, director of engineering on the Sentinel

Sentinel is recognised as a truly new generation of underwater threat detection, tracking and classification sonar. Utilising innovative composite arrays, electronic design and software algorithms, the sonar head consumes no more power than the average light bulb and operates at considerably lower source levels than more generic hybrid systems, thereby minimising the potential impact upon marine life. First demonstrated in October 2007 and delivered to its first customer in May 2008, more than 20 systems have now been ordered for a diverse range of maritime security applications.