# On the synthesis of acoustic sources with controllable near fields

## TL;DR

This paper introduces a method for designing acoustic sources that can generate specific near-field patterns in free space and ocean environments, supported by theoretical analysis and numerical simulations.

## Contribution

It presents a novel strategy for synthesizing acoustic sources with controllable near fields, including multiple pattern approximation and low far-field signature techniques.

## Key findings

- Successful approximation of prescribed near-field patterns
- Effective control of multiple disjoint near-field regions
- Low far-field signature while maintaining near-field accuracy

## Abstract

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.