| 摘要 |
PURPOSE:To decrease the number of required transmission lines to 1 and to transmit signals on a normal radio line, by using receivers for one reference point only and using transponders for other reference points, and transmitting signals through encoded and multiplexed reception time of sound pulses. CONSTITUTION:An object 1 in water is fitted with a sound source device 2 transmitting sound pulse signals f0, and signals transmitted from the device 2 are received at transponders 31-34 and a receiver 4. The transponders 31-34 respond to the signals from the device 2 to transmit sound pulse signals in frequencies f1, f2-. The receiver 4 receives the signals from the sound source 2 and the transponders 31-34 and transmits the reception signal to a buoy 6 on sea surface via a submarine cable 8. The buoy 6 separates pulse signals with different frequencies for detection, measures the reception time, converts the result into a code series and transmits the code to a ship 7 on water from an antenna. |
