UNDERWATER SOURCE LOCALIZATION USING CYLINDRICAL HYDROPHONE ARRAY AND RIEMANNIAN MATCHED FIELD PROCESSING

Abstract

The Matched Field Processing (MFP) is for defining the range and the depth of an underwater source effectively. However the algorithm is seldom used for finding the azimuthal direction of the source and is still not considered for multiple field replicas due to the variation of sound velocity. If using cylindrical hydrophone array (CHA) with 32x10 elements (ten ring with each ring of 32 elements) the rough azimuthal angle resolution, , is obtained. Then using TDOA (Time difference of arrival) of the two selected consecutive beams of CHA the system could provide the bearing accuracy up to . Then, the range and the depth of the source are the solution of the proposed Riemannian MFP with the assumption of cylindrical spreading. The proposed RMFP is on the basis of Riemannian distance which is calculated directly by solving the geodesic equation on cylinder surface. The simulations show that only with the data from selected vertical hydrophone array of CHA (there are 32 vertical arrays on cylindrical array) is enough to locate the range and the depth of underwater source precisely.