Active sonar and control method of active sonar

摘要

PROBLEM TO BE SOLVED: To provide an active sonar capable of obtaining echo sound information of a far-distant object.SOLUTION: An active sonar has: a fan beam transmission unit; a fan beam reception unit; a propagation path calculation unit; a route time calculation unit; and a horizontal distance calculation unit. The fan beam transmission unit transmits a plurality of transmission fan beams wide in a horizontal direction and narrow in a vertical direction while changing an elevation angle. The fan beam reception unit receives a reception beam wide in the vertical direction and narrow in the horizontal direction. The propagation path calculation unit calculates a propagation path of each transmission fan beam on the basis of a sound velocity profile and the elevation angle of a medium. The route time calculation unit calculates route time for propagation of the transmission and reception fan beams through the propagation path on the basis of the transmission time of each transmission fan beam and the reception time of the transmission fan beam. The horizontal distance calculation unit calculates a horizontal distance from the active sonar to an echo sound generation point on the basis of the propagation path and the route time.SELECTED DRAWING: Figure 1