Approach to active control of scattered sound field from underwater targets.

Abstract

Active control of scattered sound fields is of great significance for the acoustic stealth of underwater targets. In this paper, we propose an approach to control the target scattered field based on the measurement of a single holographic surface. Compared to existing methods, our approach significantly reduces the required number of hydrophones and only relies on the incident direction as prior information. First, we introduce a sound field separation method that uses the measurement of a single holographic surface to extract scattered field near the scatterer. Then two control strategies are presented to reduce redundant sound power outside the selected direction radiated by secondary sources in different situations. Finally, the proposed method is verified by the simulation based on finite element method and the experiment conducted in an anechoic tank. Experimental results in the tank show that the scattered sound pressure level in far-field is reduced by at least 10 dB at 2 kHz after activating the real-time control system.