Application of Acoustic Emission Signals Pattern Recognition for a Firearm Identification

In the paper, important security issue of firearm identification is addressed. State of art on the acoustic pattern recognition is widely presented emphasizing that no research is reported being conducted on the firearm identification based on acoustic signal emitted during reloading. It was demonstrated that reloading sound pattern is dependent on manufacturing technologies, dimensions, materials and other features, and thus can serve as a recognizable signature of a firearm type. In particular, the firearms manufactured out of a metal piece with milling technologies, as well as molded guns expose higher stability of the main components, and their emitted acoustic signal is characterized by wider spectrum and smaller energy than that of the guns manufactured by stamping technology out of the flat sheet metal. The respective measurement system is presented and results of the measurements are discussed. This novel system is based on two microphones and parallel processing of two registered acoustic signals, which proved to be highly effective. The results confirmed the individual characteristics of the acoustic “signature” of different types of firearms and possibility to apply the registered reloading sound in the security recognition systems.