Localization and updating by reduction of models

A model updating procedure Based on frequency responses use with a filtered inputs residue is described. A first redution is applied to the full finite element model on sensor's displacements suitabily choose from the model eigenmodes basis. At a second time, model and structure frequency responses are condensed on a common basis. The inputs residue provides linear equations hy report to perturbations of the model, hut presents a sensitivity to errors of measure. We define then a strategy of regularization allowing a statistical parameter elimination of insensitive parameters hy series of noisy measures.