| 摘要 |
PURPOSE:To receive only the reflected wave abeam to the advancing direction all the times in the case the position of a school of fish is detected from a ship underway by sensing a yawing amount of the ship based on the fine vibration of the output voltage of a gyrocompass and performing compensation. CONSTITUTION:Vibrators 17-1-17-20 constituting a wave transmitting and receiving body are provided in parallel with a hull in one line. A transmitting part 30 transmits a transmitting signal of e.g. 60kHz at every specified interval corresponding to a range width of the sonar and gives it to the vibrator 17-6-17-15 via duplexers 18-6-18-15. The sonic waves having broad directivity is transmitted. The reflected waves are inputted to the 17-1-17-20 with narrow directivity and given to mixers 16-1-16-20 via the duplexers 18-1-18-20. In the meantime, the gyrocompass 10 is connected to a computing circuit 11 having a subtracting function, where short cycle vibration of yawing is sensed and given to a tilt control part 13, to which an input of e.g. 135kHz from an oscillator 15 is inputted. The output of the control part 13 is fed back to the mixer 16-1-16-20, and the compensation is performed. |
