Perimeter security – Part 5 of 6

The importance of lighting in perimeter security applications

As an example of a 2-in-1 solution, Raytec’s Vario2 Hybrid offer the same power and distance as two dedicated illuminators.

As an example of a 2-in-1 solution, Raytec’s Vario2 Hybrid offer the same power and distance as two dedicated illuminators.

Raytec is the world leader in LED lighting for safety and security, and the company behind the Vario2 range of award winning LED illuminators, designed to enhance the performance of any security system. In this article their experts point out different aspects of importance when it comes to using illuminators in perimeter security applications.

Infrared (IR) illumination is the most common type of light used around a perimeter fence line. IR omits zero light pollution, but crucially, it allows the camera to capture night-time images covertly, without alerting potential intruders or giving them light to work by.

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. Only using white-light when it’s 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 illuminators

Another option which specifiers should consider is the use of hybrid illuminators. Hybrid illuminators provide an all-in-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 whitelight.

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. It is also equally important to consider how the illuminator will assist the camera in obtaining the highest quality images.

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

Hot Spot Reduction

Using illuminators which reduces hot spots and provides an even image across the entire scene is also a way to ensure high image quality. Raytec’s Vario2 range uses hot-spot reduction technology (HRT) to deliver a highly diffused, elliptical beam shape which targets the light where it’s needed. This supports longer distances, minimises light wastage, and ensures even distribution of light throughout the scene. The HRT system also prevents over-exposure of foreground objects; light uniformity is crucial in ensuring hot spots are minimised.

Hardware Integration

Modern perimeter surveillance systems often consist of several IP enabled devices, intended to work together to provide high levels of security. Typically, these include, IP cameras, passive infrared sensors (PIR), laser detectors and fibre optic fence sensors.

For applications using these kinds of devices, specifying an IP enabled illuminator capable of providing an automated lighting response, is essential. 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).

Camera Analytics

Using video analytics is an effective way to determine if unwanted or suspicious behaviour is occurring in a camera’s field of view. However, camera analytics are only as effective as their ability to provide a consistent, clear image. This is where lighting plays an important role. Using analytics requires often increased light levels compared to standard applications. Darkness will seriously affect the performance of the used video analytics and create false alarms.

Software Integration

In terms of specifying an illuminator, it’s important to choose one which can be integrated with the security management platform in use by the site. For example, if a site is using Milestone’s Xprotect platform, the chosen illuminator should be cable of being integrated into that system, so it can be controlled easily and lighting responses set-up to be triggered by other detection devices.

Other Considerations

For any surveillance project, choosing a luminaire that is easy to specify and install will save time and money during the initial phases of a project through to commissioning.

The use of interchangeable lenses, where beam angles can be altered on-site, is ideal for perimeter applications. It means one product can be used for several different areas and provides installers with greater levels of flexibility. It is particularly useful when illuminating the corners of a perimeter fence, where wider beam angles are generally required.

For example Vario2’s interchangeable lens system (ILS) allows the angle of illumination to be quickly and precisely adjusted from 10 to 120 degrees to match the camera’s field of view. Undertaking a lighting design helps to ensure the correct light levels are achieved across the site, and is essential for cameras to be able to capture high quality images. This provides specifiers with peace of mind and no surprises at the point of commissioning.

Note: This editorial article has primarily been produced for the security trade magazine Detektor in collaboration with SecurityUser.com.

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