| 摘要 |
A fish finder having two 1D transducer arrays vertically arranged on a ship's hull. Each 1D transducer array provides a beam having a narrow width on a plane parallel to a plane in the transducer arrangement direction, and a fan-like beam on a plane crossing the plane. Ultrasonics are transmitted toward and received from the target on the first plane, by using the fan beam of the first 1D transducer array, and received from the second plane perpendicular to the first plane by using the fan beam of the second 1D transducer array. While the beam direction of the first 1D transducer array is gradually changed, that of the second 1D transducer array is rapidly changed so that information concerning the 3D space below the water surface is obtained. The obtained information is subjected to ray tracing processing for 3D displaying of an image on a 2D screen. This arrangement enables quicker detection of fish schools. |
