Acoustic Source Location Using Long Base Line Techniques

摘要

A study is made of acoustic base line methods for detecting and locating sound sources such as trucks. The experimental system used is composed of widely separated omnidirectional receivers and a signal processor which operates on the receiver outputs. The long base lines and the highly periodic nature of the acoustic signals generated by engines of any type lead to severe ambiguity in acoustic source location. Mathematical derivations and experimental analysis have led to signal processing technique which reduce the periodic components of the source signals and preserve the random signal components for use in time-of-arrival measurements. Subsequent source location is highly successful. In the present analysis: (1) a source whose sound-pressure level (SPL) is about 100 dB re 0.0002 microbar and whose signal contains strong perodic components was detected and located using base lines of about 1000 meters; (2) accuracies in locating the sound source of several meters were achieved under calm weather conditions; and (3) identification of the sound sources was successfully performed based on spectral signatures. (Author)