Environmental effects on short-range acoustic propagation and sensor performance.
Donald G. Albert · The Journal of the Acoustical Society of America · 2008
Autonomous passive acoustic sensor systems can potentially detect, identify, and locate sound emissions from gunfire, explosions, vehicles, and animals. However, since sound propagation through the atmosphere is influenced by many environmental conditions including meteorology, ground impedance, and barriers or obstacles, these effects need to be understood and included in sensor system design to achieve accurate performance. Low-frequency short-range measurements using impulsive sources will be presented to quantify these effects on acoustic wave form shape and amplitude attenuation. In urban areas, multiple reflections and diffractions can add enough complexity to explosion wave forms that it becomes difficult for a human listener to identify them as explosions. In these areas, classical methods to determine source locations such as beam-forming or direction-of-arrival bearing estimates from time delays can fail completely. Novel signal processing methods that incorporate the complexity of propagation in these environments can produce accurate localizations. [Work funded by U.S. Army.]