Acoustic Vector-Sensor Capon Direction Estimation

The direction-of-arrival (DOA) estimation problem is of great importance in underwater applications. The traditional solution is to use a spatially distributed array of pressure sensors, and many estimation techniques have evolved for this scenario. It is well known that sound wave has both scalar quantity and vector field, while traditional acoustic pressure sensor system merely makes use of its acoustic pressure information. Vector hydrophone, also called combined sensor, is combined by traditional and omni-directional pressure hydrophone and natural dipole independent on frequency, which can co-locating and simultaneously measures pressure (scalar field) and particle velocity (vector field) of acoustic field. No doubt, the more the information, the better the signal processing effect will be.For the uniform linear array, the technology of general acoustic pressure array signal processing is reviewed in the thesis on which the technology of vector array signal processing is studied based. Then, by examining the Cramer-Rao bound in case of a single source, we show that a vector-sensor array's estimation error is smaller. In addition, expression of the Bartlett and Capon spatial spectra based on acoustic vector-sensor array are derived. Compared with the expressions based on traditional pressure-sensor array, improvements attained by using acoustic vector-sensor array of direction-of-arrival (DOA) estimation are discussed.Finally, the thesis analyses the data of trials in Mogan Mountain, and estimator result of DOA of vector array and general array are presented, knowing that experiment result is basically consistent with theory result. The technology of vector array is new, so some content in the thesis is with eisegesis. The author hopes that it is useful to development of vector array.