AN EXPERIMENT ON MATCHED-FIELD ACOUSTIC TOMOGRAPHY WITH CONTINUOUS WAVE SIGNALS IN THE NORWAY SEA

An acoustic tomography experiment in the Norway Sea with continuous wa ve (cw) signals is described. Measurements were made using a point sou rce and a vertical 560-m-long array 55 and 105 km apart. The tomograph y scheme was based on matched-field and matched-mode principles and co nsisted in ''fitting'' the media to the measured acoustic signal at th e array. The sound-speed profiles were described at some points by emp irical orthogonal functions and linear interpolation between these poi nts was applied. Two- and six-parameter descriptions of the medium wer e in fact used. The results of tomography reconstruction of the sound- speed field agreed well with the spot measurements and demonstrated th e feasibility of the tomography schemes applied.