Acoustic Tracking of Remote, Up to 4 Kilometers, Moving Sources Using Multiple Microphone Array Beamforming Methods.

Acoustic sensors can be used to detect ground and air combat vehicles at extended ranges under good environmental conditions. When installed on a vehicle, eliminating or reducing self noise and interference become the critical issues. SenTech proposes to adapt an existing sensor system to meet TACOM's requirements. An eight - element microphone array will be designed, with rugged microphone mounts and windscreens. The sensor system will be hosted by a rugedized PC workstation. An off the shelf bank of anti-aliasing filters and an integrated analog to digital converter and digital signal processor will perform the bulk of the computations. The system will carry out the functions of target detection, localization and tracking. The beam forming function will be used for nulling self-noise and interference and for high resolution bearing estimation. Two types of beam forming will be implemented: conventional delay - sum beam forming and minimum variance, adaptive beam forming. 12 to 24 fixed beams will be formed simultaneously. In Phase II the system performance will be enhanced through the use of an adaptive noise cancellation algorithm using reference sensors to further reduce the contribution of self noise.