Developing extrapolated pressure level maps from firearms

• Published in: The Journal of the Acoustical Society of America Vol. 145; no. 3; p. 1662
• Main Authors: Rasband, Reese D., Gee, Kent L., Wall, Alan T., Wagner, Caleb M., Murphy, William J.
• Format: Journal Article
• Language: English
• Published: 01-03-2019
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.5101103

This paper describes the development of spatial maps for both peak and A-weighted equivalent sound levels from various firearms, as measured with different spatial resolutions. Two outdoor datasets that adhered to the MIL-STD-1474E weapon noise measurement standard are considered. First is an extensive measurement of the M16A4 rifle at U.S. Marine Corps Base Quantico that included several shooter configurations and a circular measurement arc with 15-deg spacing and 3.67 m radius [R. D. Rasband et al., J. Acoust. Soc. Am. 143, 1935 (2018)]. Second is a measurement of many different firearms using an array with 30-deg spacing and 3.0 m radius, performed in Rudyard Michigan [W.J. Murphy et al., J. Acoust. Soc. Am. 132, 1905 (2012)]. Using these levels and conservative estimates based on spherical spreading and symmetry, level maps are created based on shooter position, weapon used, and number of shots fired. The fidelity of the extrapolation procedure and possible future improvements is discussed. [Work supported by ONR, WTB Quantico, and AFRL through ORISE.]