- Often requires power or electronics distributed along the perimeter - Environmental nuisance can require sensitivity retuning - Long-term maintenance can be higher depending on installation and cable exposure Microphonic cables detect mechanical/acoustic disturbances along the. - Often requires power or electronics distributed along the perimeter - Environmental nuisance can require sensitivity retuning - Long-term maintenance can be higher depending on installation and cable exposure Microphonic cables detect mechanical/acoustic disturbances along the. Probability of Detection (Pd) and Nuisance Alarm Rate (NAR) are the core KPIs. In practice, both technologies achieve high Pd when installed and tuned correctly. Where they diverge is context: Fibre-optic systems typically excel at localising events (e., “climb at 2,347 m on the south fence”) so. They detect vibration generated by cutting, climbing, or impacts. Where they fit well - Short-to-medium fence runs - Lower-to-medium risk sites - Projects where zoning can be coarse (segment-level) Typical limitations - Higher nuisance alarms in wind-heavy areas or where vegetation touches the. Operation is not affected by vegetation (including grass, shrubs, and trees) and these sensors are insensitive to wind, rain, snow, hail, sandstorms, fog, extreme temperatures, seismic vibration, acoustics, magnetic effects and blowing debris. They can also be calibrated to reject animal detection. Complex weather and environments — including vegetation, animals, pedestrians, vehicles, wind, rain, snow, and fog — put a great deal of pressure on the reliability, adaptability, and stability of perimeter protection. FEBUS A1 device is a Distributed Acoustic Sensing (DAS) system that provides acoustic sensing typically every 1 m over several tens of kilometers with optical fiber cable deployed on or near the highly sensitive area perimeter.
