Translator Disclaimer
18 September 2003 A new method for outlier removal in time-delay-based direction of arrival estimates
Author Affiliations +
Recently, the need to monitor restricted areas has increased. Acoustics is one of the available key techniques but there are some restrictions and constraints to consider. In situations with unknown noise and low SNR the performance of time delay based direction of arrival (DOA) estimators collapses rapidly as SNR decreases. Outliers are introduced into estimation results when signals of interest are masked by noise. There exist several methods for compensation of noise induced errors, such as averaging within subarrays, time delay selection or various minimizations. These compensation methods provide an optimum solution with respect to some criteria, but are uneffective against large errors in multiple time delays. In this paper, we present a method for removing outlayers caused by errors in time delays. First, we utilize signal propagation speed to measure an error criterion for DOA estimates. Second, estimates with sufficiently large error criterion are identified as outlayers and discarded. Effectiveness of our method is verified through experiments with simulations and real data. In both cases we are able to identify and discard outlayers and thus improve estimation reliability. Results indicate that the given method can be used to gain efficiency and robustness in DOA estimation applications, such as automatic acoustic surveillance of large areas.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Tuomo W. Pirinen, Pasi E. Pertila, and Ari J.E. Visa "A new method for outlier removal in time-delay-based direction of arrival estimates", Proc. SPIE 5090, Unattended Ground Sensor Technologies and Applications V, (18 September 2003);

Back to Top