Accuracy of Time-difference-of-arrival based source localization algorithms under temperature variations

Time-differences-of-arrival measurements play a relevant role in localizing and tracking of acoustic sources. Though a huge literature has been devoted to this topic the influence of the propagation speed on the localization accuracy has been largely disregarded. The sound speed is usually supposed to be exactly known, but actually this information is far from being available in real situations, where the environment conditions are uncontrolled and might significantly change. Therefore the accuracy of the existing algorithms under temperature variations and the consequent propagation speed deviation is of interest. Two well known closed-form localization methods are reviewed under the hypothesis that the sound speed is wrongly assumed due to unknown temperature variations. After a mathematical treatment, simulation and measurement results are shown.