There’s “an increasing interest at international level with regards the protection of harbours, vessels and critical infrastructure”, Submarine Electronics (SAES) told ''MJ''.
But the meteoric rise in computer sophistication has helped innovation keep pace, allowing for a continual improvement in accuracy and range, as well as the ability to home in on more difficult targets such as divers.
While sonar has long been used to detect ships and other vessels the Spanish company has developed a system that can ‘listen’ for a single person in a wetsuit. Its high-frequency active sonar system, DDS-03, can be used for locating underwater threats such as manned and unmanned underwater vehicles (SDV, ROV or UUV) and, of course, divers.
The problem especially with this last has always been that the acoustic signature of a person is much harder to pin down than that of a ship: it’s smaller, softer and much more amorphous than a vessel which at least has the courtesy to keep its shape fairly static.
The sonar ‘ear’ comes as a three-part system: there’s a submerged pickup which digitises the signal and sends it back to an intermediate unit: this hub controls both power supply and communications. The surface installation is where the signal is processed; here the background noise is winnowed out and the tell-tale signal recognised by SAES’ algorithms.
The system is effective: in its basic configuration it provides a full 360 degrees of coverage, including both accurate detection and tracking of underwater intruders up to a kilometre away.
However, more can be achieved by linking together a number of underwater units to create a large protection zone around vulnerable assets, whether an area of special scientific interest, a sensitive ecology, a shipwreck, port or other critical infrastructure, plus it can also offer surveillance for things like special events and anchored boats.
By Stevie Knight
