Analysis of acoustic signatures of small firearms for gun shot localization

During an ambush it is very important to identify the direction of attack for retaliation. A gunshot localizer in this scenario can alert the troops of the incoming bullet. Firing of a gun produces a high sound pressure which can be used for locating the shooting position. Such devices also find application in high security areas to listen for any probable attacks. For detecting and localizing a gunshot, an array of microphones connected to a Data Acquisition and Processing Unit is employed. The microphones listen to acoustical events and the associated system continuously looks for any signal of interest. Following the signal detection Time Difference of Arrival of the sound at the different microphones are processed to extract the positional information of a gunshot. The positional information comprises of Azimuth, Elevation and Range of the source of gunfire relative to the sensor array. We at CDAC, Trivandrum have developed an Acoustic Gun Shot Detector for small fire arms and extensive field trials were conducted for system evaluation at firing ranges. This paper presents an analysis of the Acoustical Characteristics of small firearms based on the recorded data and test results of field trials.