Publications (2)0 Total impact
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ABSTRACT: Sensor network attitude problem consists in retrieving the attitude of each
sensor of a network knowing some relative orientations between pairs of
sensors. The attitude of a sensor is its orientation in an absolute axis
system. We present in this paper a method for solving the sensor network
attitude problem using quaternion formalism which allows to apply linear
algebra tools. The proposed algorithm solves the problem when all of the
relative attitudes are known. A complete characterisation of the algorithm is
established: spatial complexity, time complexity and robustness. Our algorithm
is validated in simulations and with real experiments.
04/2011;
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ABSTRACT: In this paper we derive relations between the cross-correlation of ambient
noises recorded at two different points and the Green's function of the elastic
waves in a medium with viscous damping. The Green's function allows to estimate
physical parameters such as speeds or distances. Furthermore, this work is
extended by introducing the Green's correlation function proposed by J-L.
Lacoume in [Lacoume07]. Some recent works proved the possible reconstruction of
the Green's function for scalar waves from the cross-correlation function of
ambient noise. In this work, we consider vector waves propagating in a three
dimensional solid medium. Two approaches are developed. Firstly, we extend
theoretical derivations proposed by Y. Colin de Verdi`ere in
[ColinDeVerdiere09], relating cross-correlation of scalar waves to 1D Green's
function using linear operator theory. The second approach recasts the three
dimensional problem in the framework of Fourier theory. This allows to improve
physical understanding of the underlying physical processes as outlined in
[Lacoume07].
04/2010;
