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PID supports motion detection

CCTV systems have improved significantly in recent years. We have seen a cost decrease while the picture quality has increased at the same time. The main challenge for control room operators has always been not to miss any intrusions at larger sites while monitoring numerous screens simultaneously.

However, due to the advancements in AI and motion detection in recent years, CCTV is now marketed as a one-fits-all perimeter security solution. The promise is CCTV can now not only record an intrusion, but also detect where an intrusion happens.

This belief is problematic and introduces significant risks, especially in large sites with extensive perimeters. To reduce these risks a PID (perimeter intrusion detection) solution is an invaluable part in perimeter security. So, what are the advantages of a PID system when seen as part of a multi-layered security system?

PID systems have fewer false alarms

The main evaluation criteria for a perimeter security systems are a high Probability of Detection (POD) and a low Nuisance Alarm Rate (NAR) or False Alarm Rate (FAR) – and especially the combination of the two metrics. With most security solutions the False Alarm Rate will increase dramatically as the Probability of Detection increases by adjusting the sensitivity of the particular solution.

Making sure that environmental influences such as wind, rain, darkness, wildlife and traffic will not create any alarms is without doubt the most challenging part for a security system. This is particularly important because re-occurring false alarms will lead to security staff losing confidence in the technology and possibly delay reacting to alarms or even ignoring them altogether.

CCTV systems are very good at recording intrusion events. However, CCTV using motion detection algorithms still fall short in keeping false alarms at an acceptable rate compared to a dedicated PID system such as a VibraSector. This is especially true for recording situations with moving objects (e.g., waving vegetation, moving animals) or in adverse weather conditions (e.g., fog, heavy rain and wind), or even worse, in both scenarios simultaneously.

PID systems work in crowded environments

Crowded environments are very challenging - if not unprotectable - with motion detection CCTV. Many remote monitoring sites are forced to deactivate the motion detection feature during business hours because it generates numerous false alarms while employees and customers were passing the field of CCTV observation.

A fence-mounted PID system will only generate an alarm when somebody tries to overcome the fence. Subsequently, the system will activate and point the CCTV to the area of interest. This even works when people frequently move along the inner or outer side of the fence.

PID systems provide more time to respond to intrusions

Another challenge of motion detection CCTV is that you have to be very careful with recording outside the perimeter boundary. You will need to make sure that your use of CCTV complies with PoPIA, GDPR and other general data protection acts. Continuous filming outside the perimeter boundary might be considered as unnecessary and excessive and might not comply with the data protection principles. As a consequence, if the perimeter fence or wall is installed right at the perimeter boundary, CCTV may not be allowed to identify intruders manipulating the fence or wall from the outside of the perimeter protection structure.

A perimeter intrusion detection system (PID system) on the other hand is designed to do exactly that. The system will detect an intrusion as soon as the intruder starts manipulating or climbing over the fence or wall. Notifying the security staff about an intrusion right at the start of an intrusion is crucial since every additional second available for countermeasures increases the likelihood that burglary, theft or vandalism can be prevented.

PID systems have audio alarm verification

More cameras come with an in-built microphone and hence are able to record audio. However, since the range of these microphones is very limited, this feature only adds value in scenarios where the camera is installed very close to the target. However, in perimeter protection where the CCTV is normally installed several metres high overseeing 50 to 100 metres of the perimeter, the in-built microphone has very limited use to verify an intrusion acoustically.

The VibraTek Plus sensor cable has superior audio capability. In contrast to CCTV which records audio only at the installed location, the sensor cable records audio along the entire perimeter fence. Whereas CCTV also records conversation, the VibraTek Plus sensor cable only records what is essential to the intrusion.

This is done by converting the vibrations that occur when an intruder manipulates or climbs over the fence into a clear audio signal. This provides the security staff with an excellent means to verify alarms. This is especially vital if no CCTV is present or if no visual alarm verification is possible due to darkness or fog.

Make use of the best of both worlds

In an ideal situation, Solution House recommends using CCTV in conjunction with a PID system. The PID system provides reliable intrusion detection with very few false alarms as well as excellent audio alarm verification. In case of an intrusion, the PID system rotates the camera and points it to the exact point where the intrusion is happening. CCTV then records the intrusion and provides visual alarm verification.

The use of rotating or PTZ CCTV in combination with a PID system is economically very attractive since it requires far fewer static cameras than would be required to oversee the full perimeter, while together achieving a higher security level.

So whatever security solution your site currently has in place, a recognised PID will enable you to respond to suspicious activity quickly. For a security solution which is highly effective, good value and requires less manpower, it is hard to beat a dedicated perimeter intrusion detection system.

The VibraTek solution supplied by Samian Technologies has been independently evaluated by the UK government Centre for the Protection of the National Infrastructure (CPNI) agency. Part of the responsibilities of the CPNI is to advise high-security sites within the UK which perimeter detection system will provide the best value for money in terms of system performance and cost. More than 500 km of VibraTek sensors effectively secure hundreds of sites worldwide.

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