Forward looking sonar having first and second receiving beams

摘要

A forward-looking sonar includes a transducer array 2 which is divided into a first sub array A and a second sub array B, a first beamforming section 12a for forming a first receiving beam with the first sub array, and a second beamforming section 12b for forming a second receiving beam with the second sub array. The forward-looking sonar receives target echoes from a wide sounding area with these receiving beams. The forward-looking sonar further includes a position measurement section 12c for determining the position of a target based on the direction of the target calculated from a phase difference between the echoes from the target received by the first and second receiving beams by a split-beam method and the distance to the target calculated from time needed for receiving the echoes after transmission.