Single‐mode Closed‐loop Excitation in Shallow Water Using Two Vertical Hydrophone Arrays

An algorithm for single‐mode close‐loop excitation in shallow water using two vertical hydrophone arrays is presented. Single mode excitation is a powerful tool for studying a great variety of oceanographic processes. The desired single‐mode sound field is the only variable that needs to be given in single‐mode close‐loop excitation. In order to achieve an exact desired single‐mode sound field, two vertical hydrophone arrays are used to search out the correct vertical wave number. By analyzing the covariance of estimation value of Green’s function matrix, an optimal source array weight matrix is presented to estimate Green’s function matrix. An algorithm based on the weight matrix makes single‐mode excitation converge at maximum speed and be steady. Advantages of the algorithm are confirmed by numerical simulations. Results of an experiment performed in a coastal environment are presented.