External narrow corridors represent one of the main challenges for intruder detection technologies. One of the main issues faced by security systems relying on analytics cameras is the number of nuisance alarms or even worst: missed real intrusions. 2D LiDAR sensors are the optimal alternative to effectively and consistently solve this problem and have been successfully deployed to provide the solution.

Optex redscan corridor detection

It is common to find narrow corridors by the perimeter line, whether it is a narrow space created by vegetation growing near the fence line, a building that is too close to the perimeter wall or buildings in a high-security area which are next to each other. The challenge of protecting narrow outdoor spaces is faced by many facilities, including large residential properties, farming estates, industrial sites, governmental buildings and critical infrastructures.

Challenges of protecting external narrow corridors

Protecting narrow corridors is a complicated task for many technologies for several reasons. The first challenge in these areas is the short distance, sometimes just a couple of meters, and with occlusions that could block the field of view.

If the target is moving fast and entering/exiting the detection area in a matter of seconds, many sensors and camera analytics would not have enough time to classify objects and therefore no alarm would be triggered.

To solve this issue and in order to not miss real threats, one common approach is setting very high sensitivity in the detection devices. The problem this then generates is the triggering of nuisance alarms by any moving objects; in farming fields for instance it could be generating a high level of false alarms with the crossing of rabbits, foxes and other wildlife.

One further challenge to be faced in narrow areas are the occlusions, usually vegetation or building structures, that provide a hiding place for the intruder and reduce the detection field of view. To address this and avoid blind spots would require the costly installation of multiple devices.

How is the challenge solved with LiDAR

Our 2D REDSCAN LiDAR technology has the ability to be mounted vertically, angled and horizontally providing very accurate and ultra-fast detection in just 100 milliseconds, much faster than other similar technologies, such as radar and video analytics.

In order to effectively protect the perimeter line even in challenging narrow spaces, REDSCAN sensors can be mounted on a pole by the perimeter line and generate a vertical or angled laser wall which can detect any attempts of crossing through. In a fenced perimeter it creates an additional security layer and in an open perimeter it generates a virtual perimeter wall ensuring there are no vulnerable gaps and provide early alert of any intrusions.

Within the LiDAR detection area, different zones can be defined with an accuracy of up to 20x20cm according to the environment and can be customised to protect specific spaces, while masking sources of false alarms.

The classification criteria can be configured for each zone depending for instance on target size, distance from the ground and time of exposure to the laser, and it is therefore easy to ignore moving vegetation and wildlife, which could be a major cause of false alarms for other technologies.

The intelligence in the device allows to detect and classify as intruders the targets that meet the specific criteria so that it can alert the system of genuine intrusions almost in real-time and enable a very fast security response, whether it is deterrent events such as security lighting or audio alerts, or dispatching security guards.

Where there are occlusions, a further advantage of REDSCAN is that it helps avoid the need to use additional sensors to cover blind spots; as the LiDAR sensor when installed vertically can detect objects right below and on both sides. The entire REDSCAN range is integrated with all major VMS platforms allowing operators to get a full understanding of the situation.