Monochromatic single-mode excitation in shallow water using feedback control

An algorithm is presented to excite a single mode in a shallow water channel using a vertical source array controlled by feedback from a reference hydrophone array. The algorithm iterates between computing the source weights based on its current estimate of the mode coupling in the channel, and updating its estimate of that coupling based on the modes observed at the feedback reference array. This allows to excite high fidelity modes with confidence at a given location. The ability to control these modes depends on the accuracy with which they are observed. To this end, the authors compute the error for the linear least-squares mode estimator for scenarios where the feedback array does not span the entire water column. Finally, they present preliminary results obtained in a laboratory wave guide illustrating the successful convergence of the algorithm in a physical experiment