Perimeter Intrusion Detection Technologies FAQ

Overview of Perimeter Intrusion Detection Systems for Site Security and Surveillance


When it comes to security, perimeter surveillance and site protection, many technologies exist including smart fences, CCTV and thermal cameras, lidar, fibre optic, radars and more.

For wide area surveillance, the most common technology available is the radar. Utilizing surveillance and security technologies to protect a site brings many benefits in terms of better situational awareness, lower cost and improved effectiveness of threat detection.

But which ones to choose according to my needs? You will find here after the most frequently asked questions to select a wide area surveillance/perimeter intrusion detection technology.

What are the main physical security sensors for intrusion detection and perimeter security available on the market?

Physical Security Perimeter means physical barriers and controls that prevent or mitigate against unauthorized physical intrusions across the perimeter.

Historically used to prevent and detect intrusions in military facilities, critical infrastructure, and other high-risk sites, perimeter security solutions are now being used in many urban areas such as commercial and residential sites, retail spaces, transportation sites, etc.

There are many different technologies that are being used for perimeter protection: video surveillance systems, thermal cameras, short range radars, seismic sensors, PIR motion sensors, access control systems, alarms and notification systems, smart fencing, lighting and others.

Each security technology has its strengths and its weaknesses.  The type of systems and technologies deployed will depend on the security needs of the customer. The table below highlights the main criteria to take into account when securing a perimeter.


What is a Multi-layered perimeter protection?

Threat levels and needs have changed over time and companies are now investing in a reliable and efficient perimeter protection. A multi-layered protection solution is often considered which incorporates technologies together to ensure a better overall security. It’s important to put in place a unified approach to cross qualify incidents and intrusions alerts. Each layer should help delay, deter and detect intrusion. A layered approach is necessary to provide advanced warning of potential threats – before they cross a perimeter. Security must extend beyond the fence to detect, and identify threats while allowing security operators sufficient response time to protect people and facilities.

What to consider when designing a security system?

The proper implementation of any security system, requires understanding of the threat nature, possible avenues of approach, perimeter or surface to protect, sensor system performance, environmental conditions and more stringent government regulations and industry standards for perimeter security. Understanding how an intruder(s) can penetrate into your site, which highlights the potential breaches, can have a large impact on the selection, placement and operation of your system.


What are the factors influencing the ability of a radar to detect a target?

Many factors influence the ability of a radar to detect a target. The radar design itself, the type of target (person, vehicle), what characteristics of the target determine its measurability (size, speed), the distance from the radar to the target, the size of the target (radar cross section), the environment between the radar and the target (rain, fog) and the environment in the immediate vicinity of the target called clutter, like trees, grass, building – they all compete with the target.

How works a ground radar for wide area surveillance?

A Radar (Radio Detection and Ranging) is a detection system that uses radio waves to determine the distance (range), angle, or velocity of objects.

Ground surveillance radars are based on the use of two primary technologies: Pulsed Doppler radar technology and Frequency Modulated Continuous Wave (FMCW) radar technology. Most Pulsed Doppler radars are derivatives of military radar used for wide area surveillance, while advanced FMCW radar technology was developed specifically for wide area surveillance, site security, and force protection. FMCW radars are known to provide better range resolution and more accurate target detection, while doppler radars provide extended range and coverage areas. However, due to background clutter, typical Doppler radars are unable to detect slow moving targets or a target moving across the radar beam (tangential movement).

Radar returns are typically plotted on a screen, yet they cannot identify what the target is. When paired with a pan tilt camera, radars act as target detectors cueing the cameras to focus and zoom in on the target for proper assessment and identification. The numerous blips displayed by the radar, due to a cluttered environment, force the operator to go back and forth from target to target with the PTZ to identify and prioritize the threats: he is constrained by the well-known soda straw effect induced by the long range PTZ camera.

How works SPYNEL 360° IR camera for wide area surveillance?

SPYNEL is a real-time panoramic thermal imager with analytics software for automatic detection, tracking and classification of multiple threats.

Continuously rotating at up to 2 revolution/sec, Spynel provides powerful situational awareness through a 360-degree visualization of the surroundings. As a fully passive thermal sensor, it is invisible to intruders, not vulnerable to camouflage nor jamming, contrary to radar technologies.

Conversely with Spynel, panoramic detection and real time imagery come together: the operator can see the images of all the targets at once and is able to discriminate, quickly and without effort, the targets that are of interest. There is no such thing as a “lost track” because the operator keeps an eye at all times on the threats. It gives unique situation awareness capabilities.

The user-friendly Cyclope software display unburdens the operator: watching a panoramic image with instant detection&tracking of objects is much less taxing and much less prone to error than following a high number of dots and tracks on a map.

To summarize Spynel acts as a passive radar with eyes. Spynel® Series includes 10 different models split into 5 sensor families (Spynel-X, Spynel-S, Spynel-C, Spynel-U, Spynel-M) for short, medium or long-range requirements from 0m up to 9km radius.

How is Spynel 360 IR camera mounted?

Due to its small form factor and light weight, SPYNEL is easily mountable to a variety of surfaces including masts, poles, buildings, walls, vehicles, and more. A stable position of the SPYNEL is a key factor for successful operation.

How is SPYNEL different from a standard Pan and Tilt thermal camera?

Standard pan and tilt systems rotate but the user can only see one direction where the camera is pointing at that particular point in time. The narrow field of view (FOV) of a PTZ cause dangerous security limitations as it has no chance to automatically detect any other event in the scenery. This is known as the soda straw effect. SPYNEL IR sensor continuously rotates at up to 2 revolution/sec providing a continuous video stream from the full 360 degree FOV. This real-time video stream allows the user to view and monitor an entire perimeter at all times as well as to detect and track multiple threats simultaneously.

For perimeter surveillance of a large installation such as an airport, which technology to choose between a ground radar/PTZ camera and a 360 infrared imaging camera?

Advantages of thermal imaging technology are numerous for perimeter surveillance of large installations such as an airport.

Ground surveillance radars are based on specific emissions of electromagnetic waves to detect objects. Such radars are especially sensitive to interferences which can be generated by high perimeter fences or grids. As an active technology, radars can also disturb the other surveillance sensors used on site like the air traffic management radars. With its passive technology, SPYNEL 360 infrared imaging camera detects and tracks an unlimited number of threats in real-time over the full panorama. It guarantees that no event is missed. The combination of early warning, exceptional situational awareness and automatic alarms ensure a high level of protection of the installation.

Regarding the infrastructure required, SPYNEL can be easily installed on an existing pylon, building, terminal or even the control tower. Installed in height, SPYNEL takes advantage of the full 360 ° to scan the scenery and is not be disturbed by potential obstacles. Conversely some radars cannot be installed on tower higher than 3m because they are disturbed by reflection on the ground.

Another advantage of panoramic thermal imaging technology is the replay feature. All tracks are recorded and can be used as evidence for authorities.

Finally with the variety of increasingly complex threats and especially drone attacks, SPYNEL with its large field of view can detect both land and air threats which is not possible with ground surveillance radar.