A high-resolution spectral estimation approach for evaluating the resonances of scattering returns from submerged targets

The principal aim of this work is to estimate the complex resonant frequencies of scattering returns from the Mock-0 target. The experiments were conducted at the Naval Undersea Warfare Center. First, the singular value decomposition approach is employed for noise suppressing prefiltering where the initial estimate of the system order is obtained. Second, the eigen-matrix pencil method is employed to approximate the complex resonant frequencies. Finally, the system order and the complex resonances are determined by a systematic procedure in which the estimated results obtained from various system orders and aspect angles are compared. Echoes observed at the same aspect angle but excited by different incident pulses with overlapping frequency spectra can also be employed to obtain reliable estimations of resonant frequencies. The key feature of the proposed approach is robustness.