Contents I. Introduction
A vector hydrophone consists of either two or three identical but orthogonally oriented velocity hydrophones plus a pressure hydrophone, all of which are spatially co-located in a point-like geometry [1]. In practical applications, an array with vector hydrophones is located at or near a reflecting boundary. For example, a plane array with vector hydrophones is mounted on the submarine hulls [2]; or it is mounted on the seabed in shallow water. The four-component vector hydrophone, which is located at or near a reflecting boundary, produces the following 41 array manifold [3]: {\bf h}(\theta_k,\phi_k) = \left[\matrix{ (1+{\cal R}(\theta_{k})e^{-{i}\vartheta_{k}}){u}(\theta_{k},\phi_{k})\cr (1+{\cal R}(\theta_{k})e^{-{i}\vartheta_{k}}){v}(\theta_{k},\phi_{k})\cr (1-{\cal R}(\theta_{k})e^{-{i}\vartheta_{k}}){w}(\theta_{k})\cr (1+{\cal R}(\theta_{k})e^{-{i}\vartheta_{k}})}\right] \eqno{\hbox{(1)}}
