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Surveillance on the perimeter

Cameras have long been a feature in perimeter security, with varying reports of success and failure, often dependent on the cameras’ planning, installation and configuration, as well as their integration with other perimeter solutions and centralised management platforms. Thermal cameras became more popular as their costs decreased, and their ability to deliver images in almost every condition significantly impacted the value of cameras on the perimeter.

With the advances in video and AI analytics, vendors have been quick to tout the increased value of visual defence technologies on the perimeter. Some would go so far as to say that the right mix of cameras, analytics and AI, and onsite or cloud processing will be enough to secure the perimeter, naturally, with the help of a fence or wall to delay any intrusions.

SMART Security Solutions asked Axis Communication and Hikvision for their input to determine how far cameras have advanced in perimeter security. Can they do the job without other technologies such as beams, PIDS and other solutions to ensure secure perimeters?

According to Marcel Bruyns from Axis Communications, Axis’ thermal cameras have proven over the years that the technology, along with video analytics, is a reliable perimeter solution. However, he notes thermal cameras can integrate with and complement additional technologies well.

“Most of our perimeter solutions consist of thermal cameras for detection and optical PTZ cameras for verification,” says Bruyns. “The combination of these technologies and our device-to-device communication via VAPIX has provided many stable perimeter protection solutions, and when adding our IP audio for an early warning and deterrent, the solution becomes more robust than ever.

“On larger perimeters, we have seen electric fencing and other detectors being used as well, but it is not a must unless the site calls for it specifically. We have also provided our radar solutions to further bolster the protection and awareness on site, with all the devices being able to talk to each other to automate the control of the system in multiple scenarios.”

He adds that it is essential to remember that not every perimeter is the same, and some require additional technologies to secure the perimeter better. One of the most important aspects of a good perimeter solution is that

the technology has the time and view to detect accurately. “Sometimes the need to create a sterile zone by managing overgrown bushes is as important as the technology put in place.”

“With the technical advances in the past few years, thermal cameras have become much more reliable and cost-effective in perimeter protection and, in certain instances, surpass the old beam solution as you have the added value of video verification,” adds Hikvision’s Cornel Botha. “In some cases, multiple layers of security are still required.

For example, to be optimally protected, a prison would have a physical fence as layer one, thermal cameras as layer two, and vibration sensors as layer three.”

Reducing false alarms

Thermal cameras certainly gave perimeter security a boost when they became more affordable. However, as with optical cameras, the real benefit comes when the camera (or the software on the camera are included in the management platform) can do the 24/7 ‘watching’ and only bring humans into the equation when an event is triggered.

Marcel Bruyns

“Analytics has been part of Axis’ thermal cameras for over eight years,” says Bruyns, “and has proven itself in multiple instances.” “We have continued to improve on thermal technology and strengthen our offering by enhancing the processing ability and the analytics they use, reducing the false alarms and improving the detection of humans and vehicles.”

Bruyns also notes that Axis’ low-light cameras with Lightfinder technology have also improved and, in many instances, successfully been deployed as a perimeter solution or to ‘fill the gaps’, working in conjunction with thermal solutions, especially at short distances. However, he warns that low-light optical cameras still have the same limitations as before, especially when light needs to be added to the scene. IR attracts insects, resulting in spiders spinning webs over the camera’s lens and requiring more regular maintenance or cleaning. Optical cameras are also limited in distance when mist, fog or heavy rain occurs, which creates blind spots. Thermal cameras are not affected by this and are, therefore, the more reliable solution.

Botha adds that there will always be some degree of failure, as no analytics on thermal or low light cameras is perfect. The algorithms are trained on a specified range of motions, gestures and events. In longer distances specifically, low-light imaging cameras cannot function as well as thermal cameras as they are designed for different applications.

How far does analytics (with AI) go?

It is accepted today that AI analytics can significantly reduce the number of false alarm activations. However, how far can we trust these algorithms in recognising false alarms as well as recognising ‘intrusions’ from authorised vehicles or security personnel? For example, can the algorithms recognise an authorised guard making his rounds by facial recognition or logo identification? What about an authorised vehicle via ANPR (automated number plate recognition) moving along or near the perimeter?

Botha notes that these technologies are more widely implemented than ever before and are still gaining traction in the current market, where ‘allowlists’ and ‘blocklists’ are implemented in various scenarios to detect suspicious vehicles. “Going to the next level is the ability to connect to the SAPS database and have stolen vehicles detected, as well as use some of our technology partners for similar results.”

The same applies to facial recognition. “Facial recognition is becoming increasingly used as a better way of authentication for access control and time and attendance within companies, to ensure more accurate employee attendance and to ensure only the correct person can enter a certain area, reducing the risk of unauthorised access.”

In Bruyns’ opinion, however, this is very difficult to achieve. “ANPR, facial recognition, or the accurate detection of a guarding company logo is not that easy, and most of the time, it would be done in a very controlled environment. A thermal camera could cover up to 600m with accurate detection, but identifying a licence plate, a face, or a logo over a long distance is not as easy.”

However, Axis’ technologies reduce false alarms with its perimeter solutions by creating custom intrusion zones with specific rules, allowing guards to do perimeter checks without being detected. These zones are set up in a specific way to ensure that intruders are detected, which may result in an acceptable level of false alarms if the guards pass through a zone in a way meant to detect an intruder.

Cloud, onsite or on the edge?

Today, those responsible for perimeter security have many options for processing the data collected by cameras (and other technologies). When considering a long perimeter, how much processing can be done on the edge (within the camera) rather than on a central server or via AI services based in the cloud? With the increased processing power in cameras, it would seem logical that more can be done on the edge to reduce the load on bandwidth and servers, and even reduce the need for cloud-based AI services (and extract greater value from each camera).

According to Botha, most analytical processing is possible on the edge, and as the technology improves, it will improve. However, there are limitations to what is realistically possible. Therefore, there is a space in the market for more sophisticated AI services due to larger processing capabilities and requirements.

“All our cameras support 100% edge processing with our Axis Perimeter Defender software,” adds Bruyns. “We have been doing this for more than five years entirely on the edge and the analytics on the edge processing has improved. We continue to develop our edge processing and the AI that goes with it.”

Since the inception of the company’s edge technology, he says Axis believes that one of the major benefits of edge processing is that there is no longer a single point of failure in the system. If one camera fails for any reason, you will only lose the functionality of that device, but if the server fails, your system will be significantly impacted.

“As mentioned earlier,” Bruyns continues, “device-to-device communication would allow the entire system to perform even if the server failed. For example, with a server down, you might be unable to view the cameras. However, the thermal could still detect and instruct the IP horn speaker to play a pre-recorded message to deter; the optical cameras would still turn and zoom to the detection area. They will still be controlled by the thermal to follow the person, and all the devices could default to record to the camera until the infrastructure is up and running again.”

“I can safely say that our edge processing has more than proven itself as a robust solution using AI to detect, deter and reduce false alarm rates and reduce processing requirements on the servers.”

Perimeter surveillance on offer

In conclusion, SMART Security Solutions asked Axis and Hikvision what surveillance solutions they offer for perimeter security.

Axis offers thermal, fixed optical, PTZ (both thermal and optical) and bi-spectral cameras for perimeter security. “We complement our cameras with IP audio in various form factors, radar technology, IP strobe sirens and analytics,” notes Bruyns. “We have IP I/O devices to integrate with third-party devices as well.”

“A perimeter solution may often exist in harsh environments; these environments require field-hardened switches, which Axis also provides to ensure the solution’s uptime remains at its best. Lastly, we provide our video management software and servers to run the full solutions, but as we are an open platform company, we also integrate the full solutions with third-partner VMS manufacturers to make sure our perimeter solution can provide any business with a full surveillance system.”

For Hikvision, Botha lists some of the company’s main perimeter protection solutions:

• Radar PTZ solutions that combine a Hikvision radar sensor with a PTZ camera and deep learning capabilities to provide multi-dimensional perimeter protection.

• Hikvision’s AcuSense cameras use deep learning algorithms to detect and categorise people and vehicles accurately, reducing false alarms.

• Hikvision’s thermal cameras provide reliable perimeter protection in total darkness and difficult weather conditions.

For more information, contact, Axis Communications, +27 11 548 6780, terri.miller@axis.com, www.axis.com

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