Exploiting a Geometrically Sampled Grid in the SRP-PHAT for Localization Improvement and Power Response Sensitivity Analysis

TL;DR

This paper introduces a geometrically sampled grid (GSG) for SRP-PHAT localization, improving spatial accuracy by considering TDOA sampling and enabling sensitivity analysis and array reconfiguration.

Contribution

The paper proposes a novel GSG method for designing spatial grids in SRP-PHAT, enhancing localization accuracy and providing a tool for array sensitivity analysis.

Findings

Localization accuracy is significantly improved with GSG.

The method enables detailed sensitivity analysis of sensor arrays.

Experimental results validate the effectiveness of the GSG approach.

Abstract

The steered response power phase transform (SRP-PHAT) is a beamformer method very attractive in acoustic localization applications due to its robustness in reverberant environments. This paper presents a spatial grid design procedure, called the geometrically sampled grid (GSG), which aims at computing the spatial grid by taking into account the discrete sampling of time difference of arrival (TDOA) functions and the desired spatial resolution. A new SRP-PHAT localization algorithm based on the GSG method is also introduced. The proposed method exploits the intersections of the discrete hyperboloids representing the TDOA information domain of the sensor array, and projects the whole TDOA information on the space search grid. The GSG method thus allows to design the sampled spatial grid which represents the best search grid for a given sensor array, it allows to perform a sensitivity analysis of the array and to characterize its spatial localization accuracy, and it may assist the system designer in the reconfiguration of the array. Experimental results using both simulated data and real recordings show that the localization accuracy is substantially improved both for high and for low spatial resolution, and that it is closely related to the proposed power response sensitivity measure.