Polyreference version of subspace algorithms for output only structural identification

In this paper, we focus on the following situation for output only structural identification : several successive data sets are recorded, with sensors at different locations in the structure ; for doing this, some of the sensors, called the reference sensors, are kept fixed, while the other ones are moved for the different records. The interest of this setup is to emulate a situation in which hundreds of sensors are available, while in fact only, say, ten are actually at hand. One additional difficulty here is that the input, besides being not observed, is turbulent in nature and nonstationary. The purpose of this paper is to show how subspace algorithms can be adapted to such a situation.