  This document describes our submission to the 2018 LOCalization And TrAcking
(LOCATA) challenge (Tasks 1, 3, 5). We estimate the 3D position of a speaker
using the Global Coherence Field (GCF) computed from multiple microphone pairs
of a DICIT planar array. One of the main challenges when using such an array
with omnidirectional microphones is the front-back ambiguity, which is
particularly evident in Task 5. We address this challenge by post-processing
the peaks of the GCF and exploiting the attenuation introduced by the frame of
the array. Moreover, the intermittent nature of speech and the changing
orientation of the speaker make localization difficult. For Tasks 3 and 5, we
also employ a Particle Filter (PF) that favors the spatio-temporal continuity
of the localization results.
