Double Beamforming for wave separation and identification: robustness against noise and application on FAF03 experiment
Ocean Acoustic Tomography aims at estimating ocean celerity variations using wave travel times in the ocean. Estimation of the variations of these travel times and identification of each acoustic arrival with a theoretical ray path in the medium is necessary for tomographic purposes. These estimations and identifications are usually impossible on the recorded signals due to several wavefront arrivals at the same time or to weak Signal to Noise Ratio. Using the fact that we have two arrays of sensors : a receive and a source arrays, some alternative processings can be developped, In this paper we propose a new method : time-delay double beamforming (on the source and receive arrays) which allows wave separation and extraction of the information required for the tomography. We study the robustness of this method against noise and apply it to real data from the experiment FAF03.
beamforming time delay estimation wave identification ocean acoustic tomography (oat)