  In this paper, a new technique is applied to conduct mode identification
using ambient measurement data. The proposed hybrid measurement- and
model-based method can accurately estimate the system state matrix in ambient
conditions, the eigenvalues and eigenvectors of which readily provide all the
modal knowledge including frequencies, damping ratios, mode shapes, and more
importantly, participation factors. Numerical simulations show that the
proposed technique is able to provide accurate estimation of modal knowledge
for all modes. In addition, the discrepancy between the participation factor
and the mode shape is shown through a numerical example, demonstrating that
using the mode shape may not effectively pinpoint the best location for damping
control. Therefore, the proposed technique capable of estimating participation
factors may greatly facilitate designing damping controls.
