Ferret, A small arms' fire detection system: Localization concepts

摘要

Small arms' fire generates two distinct impulsive sounds: the shock wave created by the supersonic bullet and the muzzle blast produced at the weapon by the rapid discharge of the propellant after ignition. At short ranges, the directions of arrival and the times of arrival of these two sounds provide enough information to estimate accurately the distance to the shooter. At longer ranges, the ballistic of the bullet comes into play and the shock wave parameters are used to solve the problem. The maximum pressure of the shock wave and its period is an additional piece of information that allows the estimation of both the miss distance and calibre of the bullet. Ferret is an acoustic system designed to detect and recognize the shock wave and muzzle blast of small arms' fire. The system comprises a small array of microphones and pressure sensors connected to a standard PC-104 computer that analyses, displays, reports and logs the parameters of a recognized shot. This project is the result of seven years of a collaborative effort between Defence R&D Canada and MacDonald Dettwiler and Associates.