Selecting sampling interval of transient response for the improved Prony method

A sampling interval selection scheme for use with the improved Prony method is proposed. Since natural frequency extraction is a numerically ill-conditioned problem, a small change in the sampling interval results in a large change in the extracted natural frequencies. From the perturbation of the eigenvectors of the matrix, the accuracy criterion of the extracted natural frequencies is derived. The proposed scheme is validated using natural frequency extraction from the synthetic response, the method of moments (MM) response, and the measured response.