PARAMETRISK GRUPPDOPPLERSONARAPPARAT

摘要

Parametric array Doppler sonar apparatus includes an acoustic lens containing a flat disk-like central portion and an annular outer portion serving as a convergent lens. Multiple transducers are positioned between the lens and the focal plane so as to launch collimated acoustic beams in specified directions through the central portion of the lens and to receive reflected energy propagating principally through the annular portion of the lens.