DETERRENT SYSTEM AND ACOUSTIC APPARATUS

摘要

A system to deter intruders (11), e.g. birds, includes detector (C) which distinguishes a target life form from other moving objects and determines its vicinity or direction. Deterrent apparatus (B) responds automatically by creating a deterrent, such as a narrow focused sound beam, which is steered to follow the target while in control zone (12). The deterrent apparatus (B) may comprise a staggered line of loudspeakers approximately 34 mm apart, the horns of the speakers being sufficiently narrow to enable beamforming in the frequency range 1-10 kHz. The horns may be flared vertically but unflared horizontally. The deterrent beam may be steered by linear variation of delays across the array.