PENALIZATION METHOD FOR WAPE ADJOINT BASED INVERSION OF AN ACOUSTIC FIELD

Penalization methods are required for the successful use of full-field acoustic inversion methods in the assessment of a shallow water environment. Regularization incorporates additional in-formation about the desired solution in order to stabilize ill-posed inverse problems and identify useful solutions. In this paper the application of penalization methods to the adjoint optimiza-tion formalism is investigated. A side constraint is imposed on the optimal boundary control of a Claerbout’s wide-angle parabolic equation model. The cost function is augmented into a weighted combination of the residual norm of the measured-predicted acoustic fields and the side constraint. Using an adjoint-based conjugate gradient optimization approach, penaliza-tion results are compared for different values of the regularization parameter that controls the weight given to the minimization of the side constraint relative to that of the residual. [The research work reported in this paper is supported by the Royal Netherlands Naval College.] 1