The Role of Radar and Thermal in Enhancing Perimeter and Area Security

30.12.2020 - Nature often provides the best inspiration for new solutions. For example, some animals have developed different types of vision to match their environment – from a racoon’s night vision to a snake’s infrared sensors and a bat’s echolocation. These enhancements allow them to understand what is happening around them and detect threats. This approach works well in nature and is equally useful in protecting sites from intruders.

The nature of intrusions can be highly varied and depending on the scenario, the right combination of devices and technologies is the key to identifying and catching a potential intruder. Two technologies that work well in challenging environments are radar technology and thermal imaging. These are valuable additions to a surveillance solution, given their capabilities which help security personnel improve protection across the site.

Seeing More in the Dark

Changing ambient lighting levels and adverse weather conditions will impact the quality of visual images, making intruder detection more challenging. Also, it’s not just unauthorised people that can cause problems. Wild animals tend to wander onto premises, inadvertently triggering false alarms. Another factor which must be examined when it comes to surveillance is privacy. It may not be appropriate to mount a standard PTZ camera in some areas. In these cases, alternative methods must be sought.

Turning Heat into Images

In contrast with standard security cameras, thermal cameras work by capturing images based solely on the heat radiating from people and objects. This means they are able to ‘see’ a potential threat, regardless of the current environmental conditions, making them equally accurate in the dark and on a bright, sunny day. This is particularly important in hazardous, remote areas where there may be no light at night. Thermal cameras can also be very useful indoors, especially in situations such as healthcare environments, where privacy and personal integrity are of great significance.
While capturing images without using visible light is useful, intelligence is needed to differentiate objects captured on video, especially when the objective is to identify threats. Thermal cameras can be combined with analytics to automatically dismiss non-threatening objects and immediately notify security of potentially critical situations.
For example, a thermal camera may spot an object moving towards a perimeter or restricted area. It can then tell whether this is a non-threatening situation, such as an animal passing by, or something that needs attention, like a car or person. If it is the latter, a guard can be deployed to investigate further, while non-threatening situations are not progressed. This saves considerable time, resources and overall costs associated with investigating false alarms.
This becomes useful when monitoring large premises with vast perimeters and limited lighting, which can be difficult for security personnel to do manually. Thermal cameras allow an efficient detection of intruders, through features such as cross line detection, motion detection or loitering detection in certain areas. If an unauthorised person comes too close to the perimeter, an alarm or recorded warning message could be triggered.

Radar Waves Provide the Locations of Objects

Similar to thermal cameras, radar technology relies on a different methodology to ‘see’ objects. It is capable of detecting objects and people based on reflecting radio waves, even in challenging environments. The benefit of using radio waves over infrared or visible light is a comparative lack of interference caused by day-to-day obstructions or triggers of false alarms.
Radio waves can pass through spider webs, fog and smoke, allowing radar equipment to focus on objects of significance regardless of the conditions. They also operate independently of the visible light spectrum, and thus work unimpeded by difficult lighting conditions. This is especially useful for sites with large perimeters, such as chemical or food production plants, which must be constantly monitored.
A particular advantage of tracking the distance of objects is that radar can be set to operate within specific zones, for example within a fenced off area – again reducing false alarms from activity outside the perimeter. The drawback is that unlike thermal cameras, radar technology cannot visually identify objects. It can classify the type of object (for example, as a human or vehicle), but other devices within the surveillance solution would be needed for verification.

Non-visual Cameras Protect Privacy

While surveillance is critical when monitoring for intrusion and adverse activity, personal privacy must be prioritised when choosing a solution. Although security radars and thermal cameras detect whether a person has entered a site, identifying features are omitted. This is especially useful regarding privacy regulations, as it ensures an organization will remain safely in compliance, without missing potential threats.
In particular scenarios, this masking of identity can prove to be valuable in determining where these devices are used. For example, some public facilities have specific requirements for their surveillance solutions. Public swimming pools are often targeted by individuals looking to access the premises outside of opening hours. Unattended intruders pose a significant health and safety risk and can also damage equipment, so identifying unauthorised access is critical. However, any surveillance system implemented must be able to work in different lighting conditions and protect visitors’ privacy. In this case, radar works well, as they do not require a light source to detect intruders and can cover a wide area. Thermal cameras can also work in smaller areas in the facility – where privacy is still critical – such as outside of the changing rooms. Alerts can be sent to security personnel if motion is detected, enabling guards to verify whether a person entered the restricted area.

Optimal Solutions Require Flexibility

Finding the right solution to fit the particular needs of the business can be challenging, as there are many factors which must be considered. The size of the premises, the presence of supplementary lighting and the location of the monitored area, all play a part in determining what type of surveillance system is needed. Thermal imaging and radar technology can be valuable additions to systems, but the existing solution must be able to integrate different types of technology to suit changing needs. For example, if a larger area needs to be monitored or if the lighting conditions change.
Open network surveillance systems allow organisations this type of flexibility, to help organisations to adapt as new technologies emerge. In this way, security radars and thermal cameras can be added to enhance their surveillance to fit with existing and future challenges, ensuring that perimeter and area security solutions are always suitable, appropriate and optimised.


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