  In this paper, robust detection, tracking and geometry estimation methods are
developed and combined into a system for estimating time-difference estimates,
microphone localization and sound source movement. No assumptions on the 3D
locations of the microphones and sound sources are made. The system is capable
of tracking continuously moving sound sources in an reverberant environment.
The multi-path components are explicitly tracked and used in the geometry
estimation parts. The system is based on matching between pairs of channels
using GCC-PHAT. Instead of taking a single maximum at each time instant from
each such pair, we select the four strongest local maxima. This produce a set
of hypothesis to work with in the subsequent steps, where consistency
constraints between the channels and time-continuity constraints are exploited.
In the paper it demonstrated how such detections can be used to estimate
microphone positions, sound source movement and room geometry. The methods are
tested and verified using real data from several reverberant environments. The
evaluation demonstrated accuracy in the order of few millimeters.
