| 摘要 |
PURPOSE:To permit prior setting of a reference position by combining a radio system and a wire system and using at least one piece of transmitter as a radio transmitter. CONSTITUTION:Ultrasonic pulses are oscillated from a cable transmitter 3 by the transmission timing signals from an apparatus 2 on board the ship. A radio transmitter 5 receives the ultrasonic pulses and emits the response signal toward radio receivers 4, 4, 4. From this response signal, prescribed operations are carried out and the position is measured and displayed on a display device. Thereafter, an electrical command is given from the apparatus 2 to a wire transmitter 6 so as to oscillate ultrasonic waves. In accordance with this, ultrasonic waves are oscillated from the oscillator 6 and these are received in the receivers 4, 4, 4, thence they are operated and displayed similarly to the above. Thereafter, further the command is given likewise to a wire oscillator as well and the position is displayed. |
