| 摘要 |
According to the system for monitoring a water area with regards to presence and localization of unknown objects, which transmit sound, in particular submarines three or more listening devices (A1, A2, A3) are thrown out in an area, where indication about an unknown object has been obtained. The listening devices are provided with hydrophones and radio transmitters for transmission of received sound by modulation on a carrier. The devices cooperate with stationary radio stations (M1, M2, M3), where the sound waves are demodulated. Time correlation between the sound waves from an object received by three selected listening devices gives information about the position of the object relative to these selected listening devices. If the position of the listening devices is unknown, for example if the devices are floating free, this position can be determined by comparing the mutual time position for a particular radio signal transmitted from each listening device when received in three stationary radio stations with known positions. The listening devices may suitably also be provided with receivers for receiving radio control signals, for example relating to order for activation, selection of radio channel, etc. |
