Protecting Ports and Harbours from security threats is difficult and expensive. Traditional site surveillance depends on the challenging task of maintaining continuous, reliable vigilance by security personnel. Effective protection from sea-borne threats has the additional challenge of trying to detect small craft in relatively large areas of water. Monitoring fences and responding to false alarms from shorebased installations is time consuming and can be labour intensive.
Recent advances in ‘Intelligent Video’ systems, combined with reductions in the cost of Thermal Imaging (TI) cameras (see Figure 1), have enabled better ways to detect potential threats when compared to traditional surveillance techniques.
TI cameras have the ability to detect very small changes in the surface temperature of objects at great distance, for instance it is possible to produce a thermographic image (temperature map) of the earth from space. TI cameras have been in use for military and scientific applications for many years but the technology was expensive and needed regular maintenance. Improvements in the manufacturing process have now made TI cameras more affordable.
Relatively low cost TI cameras can easily depict the thermal image of a small vessel at several kilometres, they need no light whatsoever to function; the coldest, darkest night presents no challenge. Objects are detected by small temperature differences on their surface. However, the scene depicted by a TI camera needs careful interpretation, in most cases the human eye is an inappropriate tool to detect objects that may be classified as potential threats. This is where 'visual intelligence' plays an important role; such systems can be given a set of instructions to determine if objects in a thermal image meet pre-set warning criteria, and if they do, to raise an alarm.
Figure 2 is a composite view from three TI cameras showing the protection zone (in red) around a tanker off-loading Liquefied Natural Gas at a pier and terminal. Objects conforming to predefined criteria entering the zone alert security staff.