Coherent-broadband, white noise constraint, matched-field processing

Abstract

Coherent-broadband matched-field processing takes advantage of the temporal complexity of the signal and, therefore, offers an increased gain over narrowband processing. However, the problem of mismatch is aggravated in adaptive versions such as the MVDR. One constraint is not enough to achieve robustness in such high-dimensional spaces. Some coherent algorithms also require a large number of snapshots, leading to ill-conditioned cross-spectral density matrices in the context of the required MVDR matrix inversions. The white noise constraint algorithm developed by Cox et al. [IEEE Trans. on Acoustics, Speech, and Sig. Proc. 35, 1365–1376 (1987)], and typically used for narrowband processing, is applied to some previously derived broadband processors to enhance their robustness. The broadband white noise constraint theory is presented and validated through simulation and experimental data. [Work supported by ONR.]