Localization of acoustic source in windy environment using ray tracing

Abstract

Position estimation of sound source using ray tracing method is introduced based on wind field measurement. TDOA (time difference of arrival) estimate error occurs during outdoor sound measurement due to the atmospheric condition such as wind, temperature, humidity and so on. Such condition can possibly change the trajectories of rays. It produces erroneous propagation time information accordingly. In this study, simplex method is used to estimate the source position using ray tracing. The basic concept is to find the estimation point which generates smallest mean square error of propagation distances or times from the candidate points. At first the estimation area is set around the first estimate which is calculated from the TDOA estimation. The simplex method is then applied to each point in the estimation area. Nelder-Mead simplex method is used to find the best position that produces the minimum error in travelling distances. In order to apply the ray tracing, the wind distribution is interpolated based on the wind measurements around the boundary. Simulation and experiments are conducted to verify the performance of the algorithm.