Historically, CCTV systems have been installed for three reasons: to deter people from potentially doing something illegal, because the insurance company insisted and to record events of what has already happened. But imagine being able to actually prevent incidences from happening rather than just record what did happen.
It is easy to justify the purchase an expensive piece of equipment if, when it is installed, it starts making money. However, as CCTV systems often do not create profit and rarely add to the bottom line of a business in the short term, they can sometimes be a tough sell. There is no question that they help create a safer environment and can provide evidence to the authorities of activities that have already occurred. Furthermore, CCTV can assist greatly when faced with a public liability claim or an occupational health and safety issue with staff members. However, CCTV systems often create the most value for end-users by providing recorded images that can save an end-user, such as a shopping centre, millions in damages. This is assuming, of course, that the system is working.
Unfortunately, most CCTV systems are poorly maintained and rarely serviced. Invariably, when something does happen, a user accesses the system to extract footage only to find either the system has not been working or the images are of such poor quality that he or she cannot identify anyone or anything.
Over the last 20 years, the industry has gone through multiple technological revolutions – from VCRs to DVRs fifteen years ago, from analogue CCTV cameras to digital megapixel IP cameras over the last five years and now the migration from physical matrix switching systems to software-based video management systems (VMS). All of these changes have been built around the desire for higher resolution images combined with longer recording times. However, none of these improvements address the fact that a standard CCTV system is designed to record events that have already happened.
That said, recent developments in some specialist areas of CCTV have made it possible and affordable to enhance CCTV technology in order to identify and prevent incidences from happening. Early warning detection systems (EWDS) traditionally consisted of blind technologies such as electric fences, bollards, photo electric beams, microwave sensors and the like. The integration of thermal cameras, combined with analytics, IP cameras and a back-end VMS all linked to lighting, speakers and mobile devices can transform traditional blind EWDS into a pre-emptive tool that enables users to not only be aware of a threat, but actually see the nature of the threat. This type of design changes the way the industry should look at CCTV systems. It turns CCTV from a reactive tool providing historical evidence into a proactive system that can prevent things from happening.
Originally developed for military applications, thermal technology has, until recently, been a somewhat expensive technology. However, with defence contracts drying up globally, companies that have traditionally catered to defence and military requirements have shifted focus, creating commercially attractive thermal products for use in everyday CCTV applications. This has given rise to an increase in production volume, which in turn has seen a reduction in the cost of thermal technology. For example, as recently as five years ago, a 640 x 480 resolution thermal camera would have retailed for approximately $20K. Depending on the type of lens being used, that same level of technology today is available for less than half that price. The 320 x 240 resolution thermal cameras – still capable of seeing great distances – are half that again. As such, security consultants and managers need to better understand the capabilities of thermal cameras as this technology has the capacity to change the way they think about and deploy normal CCTV systems. When used in conjunction with analytic software, perimeter cameras can detect and trigger an alert if someone is approaching the premises anywhere from 50m out to 2km if required. This alert can then be acted upon to stop an event from occurring if a guard is on-site or if he is linked in with a speaker system on site.
Obviously, early warning perimeter protection cameras are not for everyone. There are, however, a number of vertical markets such as mining, critical infrastructure, air and sea ports, large logistics warehouses, search and rescue, rural fire, police, solar farms, councils, oil rigs, refineries, universities, military installations and government departments that can benefit from this type of technology. This technology certainly comes into its own when there are large open spaces in remote locations that need to be monitored. Thermal can provide cost-effective, invisible, long-range perimeter protection in areas lacking lighting or power. Most thermal cameras run on low power, enabling the use of a small solar panel on a trailer if cabling is not an option.
Aside from its obvious applications in perimeter protection, where else might thermal imaging provide benefits for security professionals? Some real-world examples of outside-the-box applications include:
- To monitor compost heaps in large sheds on rural properties. Believe it or not, compost can heat up in the middle of a large mass, leading to spontaneous self-combustion. Farmers have lost sheds worth $100,000. In this scenario, a thermal/radiometric (thermal camera that assigns temperature and colour to a scene) would detect the heat build-up and be able to alert the farmer of an impending fire.
- To monitor laundry. As strange an application as this may sound, there have been documented instances of heat building up in the middle of a pile of freshly dried clothes/linen, causing the pile to catch fire and burn down the laundromat. The same can occur in garbage and recycling plants.
- To locate buried bodies. Although thermal will not see through anything, it can detect a temperature difference between land that has not been disturbed and an area of land that has been dug up. The emissivity of the two areas will be different.
Some other uses for thermal imaging technology include using the thermal core and putting it in an unmanned aerial vehicle (UAV) to look for cattle on a property as well as identifying fires or electrical heat build-up in power lines. Obviously, this type of technology has created an advantage in military applications as well, enabling troops to see where the enemy is situated by flying the UAV over the battleground and looking at the thermal image transmitted on a monitor.
Some CCTV purists have an issue with thermal technology due to its limitations. It cannot identify someone. CCTV has traditionally been about resolution and identification, hence the push for megapixel cameras and hard drive recording. This might make sense in a banking environment, as well as business or retail applications. However, thermal cameras are not designed for these applications. Thermal technology is designed with early warning detection in mind – mainly external, long-distance applications where it does not matter who it is – just that someone is there when he is not supposed to be. Thermal can cut through smoke like it is not even there. Fog, sandstorms and foliage are not a problem either. People and animals will stand out in any of these situations with a thermal camera, day or night.
As mentioned, typical external detection to date has comprised photo electric beam and microwave sensors. These technologies are good; however, they are prone to false alarming whenever a rogue animal is wandering or the wind blows with any force. Another advantage of thermal is no false alarms. An image of the perimeter can be sent to a phone and security personnel will be able to tell the difference between a man and a dog. The wind does not affect the camera in any way whatsoever and intruders cannot jump over it like they can a beam.
How does thermal work – every living thing and inanimate object will absorb and emit energy (which is normally measured as temperature and referred to as heat) at a different rate. The emitted radiation will vary depending on the object that is transmitting whether it be a human, a desk, a pen or a TV as every object gives off a different about of energy or heat. Thermal cameras are able to identify and analyse the temperature differential between objects in a scene, and radiometric cameras can actually assign a temperature value to everything in that scene.
The key to the success of thermal imaging is camera placement. Thermal technology works on picking up emitted radiation (object heat) at distance. If you are looking at full bodied fixed cameras, you need to design the perimeter so there are no holes through which a perpetrator might slip past cameras. Having the cameras all pointing in the same direction from inside the perimeter, with the right distances between each camera, will ensure there are no holes in your perimeter.
There are a multitude of thermal technologies to help secure a site that encompasses a variety of challenges, including but not limited to, a large land mass. These include pan/tilt thermal cameras with digital zoom for commercial applications, as well as thermal cameras featuring continuous zoom. However, cameras of that nature often cost over $100K and need to be cooled. There are also thermal and optical combined cameras on the market. While these cameras might be a little more expensive, they provide users with the best of both worlds – optical capabilities for identification of an object or suspect during the day and thermal imaging for early warning detection at night.
There is no doubt that Thermal Cameras are a growth product in the security industry.
Megapixel versions are already on the market and allow significantly improved recognition features as well as exceptional long range performance in poor visibility conditions.
These cameras are still very expensive but can make the difference in finding people in adverse conditions at night and potentially saving lives. As the technology continues to advance and the manufacturing yields improve, thermal imaging detectors will continue down in cost.
Moreover the ability to make the pixel size in the detector array smaller will allow the use of smaller optics, which is now a significant portion of the cost of a thermal camera. Because the lens material in thermal cameras is not glass, but rather Germanium, a “metalloid” in the Carbon Group, it is quite expensive and difficult to manufacture into a lens form. In current uncooled Long Wave Band thermal cameras, the cost of a lens is generally higher than the detector once the focal length exceeds 50 – 60mm. Higher volumes also allows manufacturing savings, but it is not expected to radically change costs in the near term.
In summary, thermal cameras now offer genuinely affordable and usable solutions in the growing commercial security market for specific applications where detection rather than recognition is the paramount. Where day and night operation is essential or where low power (and lighting) are a limiting or preferred options and where seeing through atmospheric obscurants is a necessity.