Offset estimation for microphone localization using alternating projections

In this paper, we focus on solving the time delay as a separate problem to the reconstruction of the microphone and sound locations. The time delay estimation appears as one of the main steps in sensor calibration problem, once the time delays are known or estimated, we can solve the time-difference-of-arrival problems by converting them to time-of-arrival problems. In this paper we make use of an alternating projection approach for estimating time delays. We show both for simulated and real data that alternative projecting algorithm yields good estimates of the time delays, even when provided with bad initial estimations. The method is also easy to implement and comparatively fast.