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Perimeter and open spaces protection

One security concern all mines have is the protection of the perimeter and the associated open areas where intruders can enter the mine’s premises and then vanish. Many technical solutions exist to address perimeter risks, but the size of mines makes the solution chosen an expensive choice, but one that needs to be made in favour of technologies that deliver the optimal service for purpose.

SMART Security Solutions spoke to Nick Grange and Theuns van Schalkwyk from XtraVision about its perimeter solution, one that has been applied in mines (and other industries) in Africa and South America. With the proliferation of illegal mining (as an addition to the other security threats mines face), any solution chosen has to deliver results, integrate into other management platforms, and hopefully fulfil more than one task.

The solution XtraVision offers is a Distributed Acoustic Sensors (DAS) solution from SAMM FOTAS, a designer and fibre intrusion detection technology manufacturer. The system is available in three models:

• FOTAS-SF-10-EN- 10 km single channel with a four metre position accuracy.

• FOTAS-DF-30-EN – 30 km dual channel or a 60 km single channel with a four to ten metre position accuracy.

• FOTAS-SL-50-EN – 50 km single channel with a four to ten metre position accuracy.

The system is composed of the following primary components:

• The sensor cable (fibre optic).

• An interrogator.

• A processing unit (including FOTAS AI).

• The FOTAS UI.

When an event is detected, FOTAS AI communicates with FOTAS UI (pre-installed onto the processing unit) and an alarm is raised. This information is recorded in the database and is displayed to the operator. FOTAS UI can also be installed into a separate server in case multiple devices need to be controlled.

SAMM FOTAS applications

A perimeter may have numerous fence types that must be identified during the design phase as different fence types generate different signals. Therefore, the cable and installation requirements may differ. The following ratios can be used to determine how much cable will be supplied:

• Chain link: 1,5 m per 1 m fence.

• Steel palisade: 2 m per 1 m fence.

• Welded mesh: 1,8 m per 1 m fence.

Buried sensor cables are also available. These use one single mode fibre core and in the event of cable damage, will continue to operate up until the point of damage. It should be remembered that the accuracy of the detection and location reference (GPS coordinates where the breach occurred) are dependent on the soil condition. For pipeline monitoring, ideally, the sensor cable will be buried directly above the pipeline to provide the best protection.

These two applications can run as a hybrid system both on the fence line and underground.

What makes SAMM FOTAS different?

Grange explains that there are a number of reasons the FOTAS detection solution is different from others on the market.

These include:

• The quality of signal processing and nuisance alarm rate control is a result of the quality of artificial intelligence.

• The location always has its own specifications regarding artificial intelligence that must be processed. XtraVision provides this agility and flexibility (through additional development and integration).

• False and unwanted alarms: this is one of the issues with DAS (see more on the technology behind DAS at (www.securitysa.com/18459r), and the only way to overcome this is to have a good quality signal process to determine the event as well as good AI software as a filter.

• The AI is very well developed and proven on a number of sites and can be adjusted if required. For example, in the event there is a device triggering the system, such as a motor turning on and off near the fibre, this can be written into the AI so it understands the times and type of vibration, and then the signal and will no longer create a trigger.

• XtraVision has already integrated the system into local products and will continue to expand the offering.

• Detection can be done on a single single-mode fibre and the balance of fibres in the cable (the same fibre) can be used for other services such as communication, camera, audio, and third-party integrations. Many recent designs include a spanning tree network configuration, allowing for the integration and addition of these devices to the IP network; the spanning tree configuration provides a good level of redundancy in the network.

• The fibre is installed in a manner that makes use of GPS-coordinated positioning, thus creating a map on the graphical user interface. Should an alarm occur, the operator will know the location within four metres of the activation. These coordinates can be sent to a third party, such as a camera or drone device, if required.

AI instead of rules

Rule-based systems are often used in applications where the decision-making process is well understood, and the rules can be accurately defined. For perimeter security, especially for fence applications, there are so many noise alarm sources that it is impossible to define a rule for each one and expect accurate performance.

AI systems, on the other hand, can be more flexible and adaptive, as they can learn from data and adjust their decision-making processes based on the latest information. In complex and difficult-to-define applications, such as perimeter security and fence applications, it provides more accurate results and low nuisance alarm rates. AI is much more tolerant to filtering out unwanted and false alarms than rule-based systems.

Additional IoT devices

The FOTAS technology does not consume all the fibre optic cable has to offer. A single-mode fibre can run the DAS, while also allowing the use of spare fibre for networking or integrating third-party devices. It can, for example, slew cameras to zoom in on the location, or operators in the control room can communicate with the intruders via voice-over-IP.

Because road or foot-based solutions could take hours to reach the place of the breach, air-based interventions are the best option. Because of their numerous vantage points, drones are a natural choice. They can fly in a direct and optimal route to the breach area, analyse the situation through visual intake, and communicate with the intervening team. SAMM Technologies is currently in the early development stages of pairing of DAS and UAV technologies for fast intervention.

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