The importance of surveillance for security purposes cannot be underestimated. Its objective is to detect, prevent and deter criminals as well as provide evidence that can be used in their prosecution. For businesses or properties with large perimeters, standard CCTV imaging can pose significant challenges.

The biggest issue in surveillance lies in the lighting conditions of the area to be monitored, as regular CCTV cameras require adequate lighting to capture a usable image. The solution lies in the use of thermal cameras that operate just as effectively by day as by night, without the need for additional lighting.

What are the shortcomings of conventional CCTV cameras? Weather can have a serious detrimental impact on its effectiveness as heavy rainfall and dense fog can obstruct the camera's view. Such cameras are also affected by bright lights (like car headlights) and smoke which can be used to a criminal's advantage.

Another vulnerability that's easy to exploit is the fact that CCTV cameras require an additional source of light at night, which is why criminals do their best work under the cover of darkness.

One of the most useful applications for thermal cameras is perimeter surveillance and monitoring, as these military-grade cameras have low power requirements and multiple lens options to allow surveillance operators to view images in environments with little or no lighting.

Thermal camera technology detects 'heat signatures' generated from objects and people to create an image of the environment, which is viewed on screen in black and white; black represents the environment as it should be and white highlights a perimeter threat, or an exception in the environment that triggers an alarm.

Intelligent video analytics applications used in conjunction with these cameras can automatically detect threats and distribute alerts in real time, leaving security personnel to effectively manage threats to the perimeter rather than expend effort in detecting them. Video analytics technology is able to positively identify and protect against intrusion with up to 98% accuracy and can differentiate between animals, humans and vehicles, which means fewer false alarms.

Knowing the nature and exact location of a perimeter alarm can help security operators to respond quickly and appropriately and stop the intruders before any harm is done, which can be challenging in geographically-isolated areas such as estate, farm and factory perimeters, where the perimeters could be many kilometres long.

The addition of thermal cameras to an existing CCTV system is uncomplicated and is therefore advisable in those areas where conventional CCTV surveillance is insufficient or not viable.

Unaffected by bright light, thermal cameras can penetrate through dust, smoke and any adverse weather conditions with an effective detection range of between 200-400 metres, depending on the lens used. Because of this range, using thermal cameras can even be used to reduce the overall number of cameras required in a surveillance set up.

Ensuring that CCTV surveillance footage is effective on a 24/7 basis no matter what the season is one of today's biggest challenges in the security field. With thermal imaging cameras and video analytics intelligence, security operators can be assured that the perimeter is secure and that intrusion will be detected no matter the weather or time of day.

* By Laurence Smith, Executive at Graphic Image Technologies (GIT)