7 research outputs found
A comprehensive analysis of the geometry of TDOA maps in localisation problems
In this manuscript we consider the well-established problem of TDOA-based
source localization and propose a comprehensive analysis of its solutions for
arbitrary sensor measurements and placements. More specifically, we define the
TDOA map from the physical space of source locations to the space of range
measurements (TDOAs), in the specific case of three receivers in 2D space. We
then study the identifiability of the model, giving a complete analytical
characterization of the image of this map and its invertibility. This analysis
has been conducted in a completely mathematical fashion, using many different
tools which make it valid for every sensor configuration. These results are the
first step towards the solution of more general problems involving, for
example, a larger number of sensors, uncertainty in their placement, or lack of
synchronization.Comment: 51 pages (3 appendices of 12 pages), 12 figure
Geometric calibration of distributed microphone arrays
reserved4Computational auditory scene analysis exploits signals acquired by means of microphone arrays. In some circumstances, more than one array is deployed in the same environment. In order to effectively fuse the information gathered by each array, the relative location and pose of the arrays needs to be obtained solving a problem of geometric inter-array calibration. We consider the case where the arrays do not share a synchronous clock, which impairs the use of time-difference of arrival measures across arrays. Conversely, each array produces an acoustic image, which describes the energy of acoustic signals received from different directions. We jointly consider acoustic images acquired by the different arrays and adapt computer vision techniques to solve the calibration problem, thus estimating the location and pose of microphone arrays sensing the same auditory scene. We evaluate the robustness of the calibration process in a simulated environment and we investigate the effect of the various system parameters, namely the number of probing signal locations, the resolution of the acoustic images, the non-ideal intra-array calibration.A. REDONDI; M. TAGLIASACCHI; F. ANTONACCI; A. SARTIRedondi, ALESSANDRO ENRICO CESARE; Tagliasacchi, Marco; Antonacci, Fabio; Sarti, August
Geometric calibration of distributed microphone arrays from acoustic source correspondences
This paper proposes a method that solves the problem
of geometric calibration of microphone arrays. We consider a
distributed system, in which each array is controlled by separate
acquisition devices that do not share a common synchronization
clock. Given a set of probing sources, e.g. loudspeakers, each
array computes an estimate of the source locations using a
conventional TDOA-based algorithm. These observations are
fused together by the proposed method, in order to estimate
the position and pose of one array with respect to the other.
Unlike previous approaches, we explicitly consider the anisotropic
distribution of localization errors. As such, the proposed method
is able to address the problem of geometric calibration when the
probing sources are located both in the near- and far-field of
the microphone arrays. Experimental results demonstrate that
the improvement in terms of calibration accuracy with respect
to state-of-the-art algorithms can be substantial, especially in the
far-fiel