| Popis: |
The nonlinear interaction of a strong high‐frequency local sound source with a weak low‐frequency sound signal can be used to construct a system (’’parametric receiving array’’) for passive reception of the signal. Analytic formulas exist which describe the behavior of such a system. In this note, we develop a design procedure using these formulas, which leads to optimal system parameters. The procedure is illustrated by the design of parametric arrays for the reception of underwater sound signals in the 25–100‐Hz band. Beamwidths of the order of 15 ° seem feasible, while beamwidths as narrow as 5 ° are probably not feasible. Such an array could be deployed in water without the necessity of phasing sensors along the (necessarily long) aperture.Subject Classification: 25.35; 30.82; 60.10. |
