| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a relative position discrimination radio communication system which monitors the approaching ships by means of a radio communication unit for prevention of the accidents of leisure jet skiing or the collisions of ships. SOLUTION: When a radio communication unit which performs communications by selective calls with small electric power is set in a relative discrimination mode via an operating part 6, the AGC of a receiving part 3 is canceled and a transmission timer is actuated in response to the setting of the relative discrimination mode. Then a relative position discrimination signal is outputted to a DTMF 9 from a control part 4 to be converted into a DTMF and transmitted via a transmitting part 2. Thus, a receiving state is set. The signal received at the part 3 is detected by the DTMF 9 and fetched if the signal is identical to the relative position discrimination signal. Then the part 4 produces the control signals in plural steps in response to the distances set between the receiving levels and the stations of opposite party sides and outputs these signals to the equipments which need the monitoring of the approach of ships.</p> |
