On the synthesis of acoustic sources with controllable near fields

In this paper we present a strategy for the the synthesis of acoustic sources with controllable near fields in free space and finite depth homogeneous ocean environments. We first present the theoretical results at the basis of our discussion and then, to illustrate our findings we focus on the following three particular examples: 1. acoustic source approximating a prescribed field pattern in a given bounded sub- region of its near field. 2. acoustic source approximating different prescribed field patterns in given disjoint bounded near field sub-regions. 3. acoustic source approximating a prescribed back-propagating field in a given bounded near field sub-region while maintaining a very low far field signature. For each of these three examples, we discuss the optimization scheme used to approx- imate their solutions and support our claims through relevant numerical simulations.