Source Localization With Distributed Sensor Arrays and Partial Spatial Coherence

Abstract

Multiple sensor arrays provide the means for highly accurate localization of the (x, y) position of a source. In some applications, such as microphone arrays receiving aeroacoustic signals from ground vehicles, random fluctuations in the air lead to frequency-selective coherence losses in the signals that arrive at widely-separated sensors. We present performance analysis for localization of a wideband source using multiple, distributed sensor arrays. The wavefronts are modeled with perfect spatial coherence over individual arrays and frequency-selective coherence between distinct arrays, and the sensor signals are modeled as wideband, Gaussian random processes. Analysis of the Cramér-Rao bound (CRB) on source localization accuracy reveals that a distributed processing scheme involving bearing estimation at the individual arrays and time-delay estimation (TDE) between sensors on different arrays performs nearly as well as the optimum scheme, while requiring less communication bandwidth with a central processing node. We develop Ziv-Zakai bounds for TDE with partially coherent signals in order to study the achievability of the CRB. This analysis shows that a threshold value of coherence is required in order to achieve accurate time-delay estimates, and the threshold coherence value depends on the source signal bandwidth, the additive noise level, and the observation time. Results are included based on processing measured aeroacoustic data from ground vehicles to illustrate the frequency-dependent signal coherence and the TDE performance.

On the Joint Time Synchronization and Source Localization Using TOA Measurements

“…Recently, source localization using wireless sensor networks (WSNs) has attracted great research efforts [1][2][3][4]. To determine the source position, positioning parameters such as time of arrival (TOA), time difference of arrival (TDOA), received signal strength (RSS), and angle of arrival (AOA) are commonly used.…”

Multiple-array passive acoustic source localization in urban environments

“…Source localization with distributed sensor arrays and partial spatial coherence has been studied in the context of plane wave propagation. 24 However, matched field processing using multiple arrays has not been considered previously.…”

Explosion localization via infrasound

“…The DOA estimates are said to be far field, since the aperture of each subarray is assumed to be small compared to the source distance. This technique has application across a broad range of interest, from nuclear treaty monitoring, 1 to vehicle tracking, 2 to the conventional detonations 3,4 described in this study. DOA-based methods of localization are prone to uncertainties arising from atmospheric, 5 environmental, 6 and intrinsic 7 factors.…”