| 摘要 |
<p>11 The invention relates to a method of and a system for remote control of individual electronic equipments (R), which are spread out across a large geographical area. In particular it concerns activation of radio transmitters spread over the water surface and cooperating with hydrophones for taking up sound waves from submarines in order to localize these submarines. In order to achieve selective activation of the electronic equipments, electromagnetic waves or sound waves are transmitted with given relative time positions from at least three fixed stations (I, II, III) having known geographical positions. In each electronic equipment the waves are received and compared as regards their relative time positions at reception, activation of an equipment taking place only if a given criterion as regards the mutual time positions is fulfilled. Hereby activation of equipments will take place only within a given small zone of the large area. The position of the small zone is determined by the relative time positions of the transmitted waves, which can be varied in order to select different zones.</p> |
