Accuracy Study on Target Localization Using Acoustic Bearing Measurements Including Urban Reflections

This paper studies the localization accuracy of a target in urban environment with line-of-sight conditions to the sensors based on acoustic bearing measurements. Instead of a commonly used wave-based approach, we focus on an information-theoretic analysis and derive the Cramér-Rao bound based on bearing measurements of direct wave and first-order reflections to predict the achievable localization accuracy. Hereby, we observe an improvement in accuracy by accounting for additional bearing measurements of reflected waves. We validate the match between predicted and actual performance in Monte Carlo simulations and field experiments in an urban environment. For this purpose, we propose an estimator that extends the classical bearings-only localization with bearing measurements of first-order reflections. Finally, we use a Cramér-Rao bound based optimization criterion, that accounts for direct and reflected waves, to optimize sensor placement in urban environment.