Scanning radar isn’t a new technology. In fact, it has been used for many years now in both military and aviation applications. However, there’s a growing concern that, outwith these environments, not enough people – even those among the expert community – are fully aware of its true capabilities.
Accurately positioning radar in the hierarchy of security systems is almost impossible because true like-for-like comparisons are simply not being made. Whether it be on a direct cost or capability basis, radar’s unique combination of features blurs the distinctions: thus it’s far better to consider applications rather than solutions.
That’s the firm belief of Phil Avery, managing director of radar solutions specialist Navtech Radar.
“Our key challenge is one of understanding and, by extension, education because on the face of it radar appears to offer the same capabilities as several less costly technologies,” he explained. “However, if you need to ensure a high level of security on a complex site then radar may well be more cost-effective than a line-of-sight, perimeter or broken-beam solution.”
Avery continued: “Radar offers a 360o monitoring capability. It also allows the introduction of complex rules and algorithms which enable the numbers of false alarms generated by a security system to be reduced dramatically.”
That’s especially important for sites where there are a lot of complex movements. Over time, a radar-based system can be configured and tuned to account for legitimate activity while detecting and warning of suspicious movements in a similar way to how a security officer might cope with the task.
“Many traditional detection technologies also require the construction or maintenance of physical barriers,” continued Avery.
“The latter can also represent a major investment, and one which has to be factored into the overall solution cost. They also restrict movement and flexibility. That being the case, they’re simply not an option in some circumstances, for example over water or where legitimate movement takes place within the detection area, such as on an airfield runway or along a railway line.”
Fitness for purpose
Avery doesn’t dismiss competing technologies. Rather, he feels, it’s a case of ‘fitness for purpose’.
“If you’re looking to detect intruders before they get to your fence or boundary, and detect and track them inside and outside your perimeter as well as know their exact location and history of movement, then radar is the most suitable technology for this.”
On the other hand, Avery told Info4Security that if you simply need to detect whether someone is close to or touching your perimeter, and have the resources to react to a certain level of false alarms, there are many other suitable technologies to choose from.
For applications where detection on the perimeter alone (or any other narrowly defined area) isn’t sufficient, it’s fair to say that radar comes into its own.
“This level of security and functionality isn’t always necessary,” Avery suggested. “It’s generally limited to applications where you’re trying to detect intrusions in advance and respond to them immediately and effectively. Nuclear facilities and airports are typical examples.”
Appreciating the benefits of radar
From Avery’s perspective, then, the slow implementation of radar technology for commercial applications is at least in in part due to the lack of an appreciation of the benefits of radar.
There are misconceptions relating to cost and, often, a presumption of the need for vision-based systems for certain detection and monitoring applications. Yet in the transport sector, Navtech Radar is already proving radar solutions are a viable alternative to video.
In southern England (on the A3 near Guildford, to be precise), the company has provided the Highways Agency – operator of all strategic roads in England and Wales – with an Automated Incident Detection (AID) solution for the Hindhead Tunnel.
This is a world first AID application which has radar replacing wide-area video monitoring and driving PTZ cameras to direct tunnel operators’ attention to any untoward occurrence.
The system is operating with very low false alarm rates and this has led Trafikverket, the Swedish national transport administration, to adopt radar as its primary monitoring system for above-ground monitoring of stretches of the E4 motorway around Stockholm.
There, inclement weather is common, especially in winter, and gives rise to conditions which can completely defeat video. Radar, by contrast, continues to give accurate, real-time warnings of obstructions in the running lanes (especially important on the E4, as sections of it have no hard shoulder).
Warnings and instructions are then provided to drivers in the locality via overhead variable message signs, in turn significantly increasing safety. This is all happening over extended stretches of carriageway which would make the use of video cost-prohibitive.
System specifics: realising radar’s capabilities
Like Navtech’s other products, the ClearWay radar system used for road applications operates in 360o and has a range of 500 metres in either direction, thereby allowing one system to monitor 1,000 metres of road in total.
“In the traffic management arena, we’ve already successfully dispelled the ‘only vision-based systems are good enough’ myth in a real-world setting,” urged Avery.
“For safety reasons, accurate, real-time detection of a stopped vehicle or lost cargo is most important in a road tunnel environment and also in applications such as the E4 where detection and reaction has to take place in a matter of seconds in order to be effective. All of these same attributes, I would say, have direct applications in the security sector.”
Navtech’s AdvanceGuard security systems can detect a walking man out to a range of up to 1,000 metres. The company’s Witness processing and control system provides the ‘brains’ and is in many respects the tool which realises radar’s capabilities.
“As with video and other sensors, radar only provides information on an environment,” outlined Avery. “It’s the post-processing, provided in AdvanceGuard’s case by Witness, which decides whether or not there’s anything important going on.”
Witness allows users to define detection zones and apply rules which dictate whether alarms are generated.
“On-screen within Witness you can draw active detection zones. At the simplest level, that allows you to position virtual ‘gates’ to replace physical barriers. It introduces an effective security solution which can still allow unfettered movement, but you can also monitor and change what goes on over the course of a day.”
Introducing pseudo-intelligent monitoring
A certain footpath might only be open to all during daylight hours, for instance. Anyone using it then needn’t cause an alarm to be generated, but that might change at night. It might be that a watch needs to be kept on people or other traffic moving in one direction but not another – those approaching might be considered a risk, while those moving away might not be. Similarly, those approaching from the left are OK but those coming from the right aren’t.
In truth, the need might be to catch movement in one area of a yard where there’s long-term storage going on and so a theft risk more likely, but still allow work to go on in another.
“The rules can be very complex and introduce the kinds of pseudo-intelligent monitoring that we might expect of a human observer,” explained Avery. “On the face of it video analytics may appear to be able to do many of the same things, but in practice it doesn’t have accurate speed, direction and location information and also suffers from environmental conditions as well as limited coverage.”
Proactivity as part of the mix
As well as allowing the continued flexibility of other operations besides security, radar can also provide advanced warning and thus what you might call a more proactive security stance.
Avery cites a number of specific examples, including that of a UK car storage facility where thieves had, over a period of time, surreptitiously weakened fencing before breaking in and making off in one night with four cars worth GB pound 200,000.
The roads into the facility were monitored but, on the night of the actual theft, there was a heavy frost and the thieves made their getaway across frozen fields.
Something similar happened in another example involving the premises of a metals recycler in southern England: while the road access was monitored, the marshy land to the rear was not. A criminal gang spent several evenings installing boards which vehicles could drive over and then, in the course of a single night, made off with non-ferrous scrap metal worth tens of thousands of pounds.
“Such crimes require a certain level of planning and determination but they do happen,” stated Avery.
“A 360o radar security solution would have allowed all sides of those facilities to be monitored as well as those areas beyond the businesses’ own perimeters – a crucial aspect in these cases. Suspicious or untoward activity could have been detected and investigated. Thermal fences, fence sensors or buried wires would not have provided any advance warning in these circumstances.”
Can video accomplish what radar demonstrably does?
A counter-argument from some quarters might be that video could have been useful but, as far as Avery’s concerned, it cannot do what radar can.
“Even if we ignore for a moment the issues of poor or variable light conditions, an issue with wide-area cameras is that they need a certain level of detail for video analytics to work. That means, for instance, that a certain number of pixels have to be illuminated before a trigger occurs. It needs the camera to be pointed in the right direction, but it also means that, as ranges increase, the sizes of the objects needed to excite those pixels also increase.”
Avery continued: “You just don’t get enough resolution at range. One solution might be to give a thermal camera a very narrow field of view, but to cover a large area would need a massive number of cameras. At the very top end, there are thermal systems which can detect throughout 360o. These are used in applications such as detecting forest fires. That represents perhaps the best case scenario for thermal camera usage: where you are detecting a very hot event on an ambient background. I’m not yet aware of a commercial scanning thermal system which can detect humans, though.”
Radar looks at a 360o area in 2o segments. It does so very intently and at speed, providing a level of surveillance which Avery believes is “unrivalled by optical systems”.
In conclusion, he told Info4Security: “It’s no accident that radar is the sensor of choice for protecting critical infrastructure as well as for military, naval and civil aerospace applications. However, it’s time for end users and specifiers alike to recognise that the same capabilities are now available to the wider civil security market.”
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