2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/117745Passive imaging is a new technics which has been proved to be very efficient, for example in seismology: the correlation of the noisy fields between different points is strongly related to the Green function of the wave propagation. The aim of this paper is to provide a mathematical context for this approach and to show, in particular, how the methods of semi-classical analysis can be be used in order to find the asymptotic behaviour of the correlations.25 pages, 0 figureMathematical PhysicsSymplectic Geometry86A15;35S30;35Q72;60G60text