Don’t Use Microwave To Defend Perimeter Fence Structure unless there’s space on both sides.
Using Microwave For Perimeter Fences – Microwave detection can be a poor choice for protecting actual fences, as the parabolic detection shape may pick up activity on the public side of the fence if the perimeter is not professionally planned.
Instead, if you need to protect physical fences only, from cutting attacks and intrusion involving climbing, you should be thinking Foptic cable, zoned powered fencing, capacitance e-field technology, Intrepid MicroPoint and other options that are attached to the fence itself. High security perimeter solutions might link a microwave perimeter system to a fence detection system.
If you pull the stripline detection in from the fenceline, or if both sides of the fence are controlled space, it’s a different matter. Stripline uses long microwaves to create a parabolic trough – a detection field wider than it is high. Stripline transceivers and transducers are located virtually at ground level, so they give excellent protection against crawling attacks. In terms of range, you’re looking at 10m as a minimum, up to about 200m maximum.
Reliability is something you’ll be partly responsible for. Be sure to install microwave systems across open ground with excellent line-of-sight between transceiver and transducer. Bear in mind that microwave stripline solutions are beam interruption sensors and that means anything that gets in the way of the beam can be a problem – trees, snow, cats, dogs, foxes, possums, fast-growing grass in the spring, kids on BMX bikes and all the rest of it.
Reliability with all external electronic security devices is a balance between sensitivity and reliability. Plenty of modern microwave systems rave about their ability to ignore 100-pound dogs and flocks of rosellas but you should be aware that the sum of most signal processing is attenuation – you are giving up sensitivity.
The ability to ignore given signals is a matter of tweaking threshold levels. Whether this is achieved with dipswitches, pots or signal processing, the result is the same – a reduction in sensitivity. For a microwave system, making a differentiation between the signal of a lean, crawling man and a stray rambling Rottweiler is going to be hard to consistently manage.
Using Microwave For Perimeter Fences
Other issues with microwave for physical fences can include sensitivity to nearby traffic, instability when compared with equivalent AIRs solutions in some applications, inability to handle undulating ground, and sensitivity to signal reflections from steel structures in the detection zone.
If that all sounds negative, the advantages of microwave perimeter systems include good cover for cost, ability to detect climbing and crawling attacks, ability to ignore warm air currents, rain and fog, being almost impervious to masking or blinding without activating an alarm, and higher levels of sensitivity when compared to AIRs systems.
If you have space to protect both sides of the fence and your real estate is flat, microwave is an excellent option – especially if you have on-site patrol teams and a team of diligent landscape gardeners. Bear in mind perimeter detection is the application of an extra layer of detection that buys you time to get a response activated before there’s a breach of the main building/s on your site.
If you decide to use microwave for perimeter fences just be sure to give the detection zone space to propagate without detecting authorised movement outside your fenceline.
More news from SEN – read more about microwave detection zone shape here.
“UsinG Microwave For Perimeter Fences.”
