International audienceIn this article, passive acoustic sensor network localization is presented and applied to geometry structure monitoring. The methodology relies on passive travel-time estimation, which is here defined as the retrieval of an inter-sensor propagation delay, using uncontrolled ambient sources in an homogeneous acoustic propagation medium. Our approach relates to passive linear systems identification through the use of codas correlations to form estimators. We provide practical performances of such estimators and propose two approaches for geometry monitoring, both illustrated in the case of a steel beam
