BAE Systems, 6400 Tracor Lane 27-16, Austin, Texas 78725, USA.
J Acoust Soc Am. 2011 Apr;129(4):1748-59. doi: 10.1121/1.3557045.
Analysis of recorded acoustic gunshot signals to determine firearm waveform characteristics requires an understanding of the impulsive signal events, how the waveforms vary among different sources, and how the waveforms are affected by the environment and the recording system. This paper presents empirical results from waveforms produced by different small firearms and an analysis of their variations under different and controlled conditions. Acoustic signals were generated using multiple firearm makes and models firing different ammunition types. Simultaneous recordings from the microphones located at different distances from the source and at different azimuth angles (from the line-of-fire) were used to study source characteristics and sound propagation effects. The results indicate that recorded gunshot waveforms generally consist of multiple acoustic events, and these are observable depending on the received distance and azimuth angle. The source blast size, microphone distance, and microphone azimuth angle are the primary factors affecting the recorded muzzle blast characteristics. Ground or object reflections and ballistic shockwaves and their reflections can interfere with the muzzle blast waveform and its measurements. This experiment confirmed and quantified the wide range of correlation results between waveforms recorded from different source, microphone distance, and microphone angle configurations.
分析记录的声学枪声信号以确定枪支的波形特征，需要了解脉冲信号事件、不同来源的波形如何变化，以及环境和记录系统如何影响波形。本文介绍了来自不同小型枪支产生的波形的经验结果，并分析了它们在不同和受控条件下的变化。使用多种枪支制造和模型发射不同类型的弹药产生声学信号。从位于声源不同距离和不同方位角（从射线路径）的麦克风同时记录，用于研究声源特征和声音传播效应。结果表明，记录的枪声波形通常由多个声学事件组成，并且这些事件取决于接收距离和方位角是否可见。声源爆炸规模、麦克风距离和麦克风方位角是影响枪口爆震特征的主要因素。地面或物体反射以及弹道冲击波及其反射会干扰枪口爆震波形及其测量。该实验证实并量化了从不同声源、麦克风距离和麦克风角度配置记录的波形之间的广泛相关性结果。
