Acoustic methods for tactical surveillance

Abstract

Smart acoustic sensor systems can be deployed for the automatic detection, localization, classification and tracking of military activities, which are inherently noisy. Acoustic sensors are appealing because they are passive, affordable, robust, and compact. Also, the propagation of sound energy is not limited by obstacles that block or obscure the clear line of sight that is required for the effective operation of electromagnetic systems. Methods, with examples, for extracting tactical information from acoustic signals emitted by moving sources (air and ground vehicles) are provided for both single sensor and multiple sensor configurations. The methods are based on processing either the narrowband or broadband spectral components of the sources’ acoustic signature. Weapon firings generate acoustic impulses and supersonic projectiles generate shock waves enabling source localization and classification by processing the signals received by spatially-distributed sensors. The methods developed for land-based acoustic surveillance using microphone data are also applied to hydrophone data for passive acoustic surveillance of the underwater environment.