Acoustic Source Localization Using Time-Delay Estimation Brent Kirkwood M.S. Thesis Duration: 6 Months (February 2003 - August 2003) Supervisor: Finn Jacobsen In cooperation with Brüel & Kjær Sound & Vibration A/S Download Full Report (1.8 MB - PDF)

Abstract The angular location of a jet airplane can be estimated by measuring an acoustic direction of incidence based solely on the noise produced by the aircraft. Methods for determining the direction of incidence based on sound intensity, the phase of cross-spectral functions, and cross-correlation functions are compared. Cross-correlation based algorithms for passively locating jet aircraft were chosen as most suitable and implemented in a four-element multi-dimensional microphone array. Various time-delay estimation techniques based on the cross-correlation functions are compared through simulations and measurements. A time-delay estimation method based on locating a zero-amplitude crossing in the Hilbert transform of the cross-correlation function appears to provide the most accurate results in many situations but breaks down somewhat easily in harsh acoustic environments. It is demonstrated that a balance of robustness and accuracy can best be achieved by using a method based on simply locating the maximum amplitude in a cross-correlation function. Publications Kirkwood, B. C. (2003) Acoustic Source Localization Using Time-Delay Estimation. Master's Thesis.