Localization and Contribution of Underwater Acoustical Sources of a Moving Surface Ship

Benoit Oudompheng (1) , Barbara Nicolas (2, 3) , Lucille Lamotte (1)

1 MicrodB
2 GIPSA-SIGMAPHY - GIPSA - Signal Images Physique
3 Imagerie Ultrasonore

With the advent of new standards for the regulation of acoustic radiation from ships, the measurement of the underwater acoustical radiation of surface ships has become a new concern. This paper proposes array signal-processing methods for loca-lization and estimation of the spectral contributions of underwater acoustic-noise sources of moving surface ships. Beamforming for moving sources is used for localization of the acoustic-noise sources. Then, deconvolution of the point-spread function in the beamforming is performed to estimate the noise-source contributions in this underwater application. Among the classical methods of deconvolution in an aerial environment, the source density modeling method is chosen. However, weighting of the beamform-ing for moving sources is not adapted to the study of large vessels such as ships, which induces the localization of nonphysical sources. A new beamforming weighting strategy is proposed to deal with this issue. In addition, as beamforming for moving sources suffers from poor resolution at low frequencies, a passive synthetic aperture array algorithm is proposed here to successfully improve the resolution. A unique experiment was performed to validate the proposed methods, on Castillon Lake, Alpes-de-Haute-Provence, France, with a towed surface ship and controlled noise sources. In these experiments, the localization performance of the beam-forming for moving sources is improved by the synthetic aperture algorithm. Moreover, the new weighting strategy provides better estimation of the contribution of the sources from the deconvolu-tion results. Index Terms-Beamforming, noise mapping, pass-by noise, underwater acoustics.

Domaines: Traitement du signal et de l'image [eess.SP]

Benoit Oudompheng, Barbara Nicolas, Lucille Lamotte. Localization and Contribution of Underwater Acoustical Sources of a Moving Surface Ship. IEEE Journal of Oceanic Engineering, 2018, 43 (2), pp.536-546. ⟨10.1109/JOE.2017.2699260⟩. ⟨hal-01699595⟩