From critical infrastructure to private property, perimeter protection systems are used in a wide variety of applications. According to Raytec, all tend to have common security goals: they are deployed to restrict access, detect and deter crime and protect important assets. And there are key things to consider when specifying an illuminator for use as part of a perimeter protection system.

Infrared and white light

Infrared (IR) illumination is the most common type of light used around a perimeter fence line. IR emits zero light pollution (so not to disturb the surrounding area), but crucially, it allows the camera to capture night-time images covertly, without alerting potential intruders or giving them light to work by, Raytec stresses.

Callum Ryder says: ”Once the camera has detected an intruder, the site may choose to raise an alarm. This is where white-light is often deployed; automatically triggered as a flashing deterrent to ward off an intruder, or used to provide accurate positive identification of the intruder.”

He emphasises only using white-light when it is needed ensures light pollution is kept to a minimum while still providing optimum levels of security. In some instances, white-light may still be chosen to illuminate the entire perimeter, but due to light pollution, and the fact that the camera is more receptive to IR, means white-light is often preferred as a deterrent.

Hybrid

Hybrid illuminators provide an allin- one solution, combining both IR and white-light into a single unit. This means one illuminator can be used for both covert surveillance, and as a white-light deterrent. Hybrid allows the user to control the wavelength and switch seamlessly between IR and white-light.

Quality and distance

Perimeter fence lines often cover large areas, so distance and coverage of an illuminator is one of the main things for a specifier to consider. However, it is also equally important to consider how the illuminator will assist the camera in obtaining the highest quality images, Callum Ryder stresses.

”Illuminators able to deliver longer distances may allow cost savings by reducing the total number of illuminators across the site. It may also allow the user to reduce costs in terms of the numbers of cameras, lighting columns, cabling and other ancillary equipment needed as part of the installation”, he says.

Hardware integration

For perimeter applications using IP cameras, passive infrared sensors, laser detectors and fibre optic fence sensors, specifying an IP enabled illuminator capable of providing an automated lighting response, is essential, according to Raytec.

”For example, if a PIR sensor detects movement from an intruder, an alarm could be raised to automatically turn on the white-light (so the intruder can be positively identified) or put the lamps into deterrent mode (to ward off the intruder)”, Callum Ryder says.

Software integration

Raytec believes it is important to choose an illuminator which can be integrated with the security management platform in use by the site.

Callum Ryder says: “For example, if a site is using Milestone’s Xprotect platform, the chosen illuminator should be capable of being integrated into that system, so it can be controlled easily and lighting responses set-up to be triggered by other detection devices.”

Camera analytics

Cameras with video analytics are often used as part of a perimeter surveillance system. Lighting plays an important role in helping the cameras to provide a consistent, clear image.

One way to help ensure a good image is to select an illuminator which uses technology which reduces hot spots and provides an even image across the entire scene.

”Camera analytics will often require increased light levels compared to standard applications. Even the best cameras will still produce noisy images in darkness that will seriously impact the performance of camera analytics and create false alarms. No light, no camera analytics”, says Callum Ryder.

Lighting design

According to Raytec, lighting design should be considered an essential part of specifying lighting for a perimeter security application.

“Undertaking a lighting design helps to ensure the correct light levels are achieved across the site and are essential for cameras to be able to capture high quality images. For an installer, a lighting design also provides a useful reference which becomes an important document during the installation and commissioning process”, Callum Ryder concludes.