Citation

Ferguson BG, Lo KW. J. Acoust. Soc. Am. 2012; 131(4): 3312.

Affiliation

Maritime Operations Division, Defence Science and Technology Organisation, Australian Technology Park, Eveleigh 2015 NSW, Australia, Brian.Ferguson@dsto.defence.gov.au.

Copyright

(Copyright © 2012, American Institute of Physics)

DOI

10.1121/1.4708389

PMID

22501602

Abstract

Acoustically, sniper gunfire is characterized by a muzzle blast caused by the discharge of a bullet from a rifle and a ballistic shock wave emitted along the trajectory of a supersonic bullet. The location of the firing point can be estimated by using a small microphone array to measure the differences in the angles- and times-of-arrival of the muzzle blast and shock wave. Traditionally, the bullet is assumed to travel at constant speed along its trajectory which, in practice, can lead to significantly biased range estimates. This problem is solved by invoking a physics-based model to describe the deceleration of the bullet along its trajectory. The ballistic model parameters are the initial (or muzzle) velocity and ballistic constant of the bullet, which are assumed to be known a priori. The performances of the traditional and model-based methods for ranging the point of fire are evaluated using 2,500 rounds of 5.56 and 7.62 mm ammunition fired at ranges of 75, 175, 275, 375 and 475 m under two (low and high) wind speed regimes. It is found that the localization errors of the model-based method are smaller by an order of magnitude when compared with those of the traditional method.

Language: en