Subspace identification algorithms have proven useful for the output-only identification of the eigenstructure of a linear MIMO (Multiple Input - Multiple Output) system subject to uncontrolled, unmeasured, nonstationary excitation, a situation encountered in structural identification of vibrating structures subject to natural excitation.  As a matter of fact, in the latter area of vibration mechanics, it is a common practice to collect data from sensors with varying locations, using a combination of fixed and moving sensors. This paper investigates how subspace algorithms must be adapted to cope with such a situation.

Keywords : eigenstructure identification, subspace algorithms.