| 摘要 |
<p>An optical communications system which facilitates rapid establishment of communications between two stations (1, 2). The system uses acousto-optic cells (5, 6) for scanning and frequency modulating a laser beam. The frequency shift introduced by the cell (6) is indicative of the direction of arrival of the beam at a remote station (2). By detecting the shift, the relative positions of the two stations (1,2) may be deduced. The invention is suitable for use with secure communication systems and IFF systems.</p> |
