| 摘要 |
A problem that can affect radars and sonars arises from the fact that in addition to echoes of their own transmissions, installations can receive strong interference from similar installations when their antennas point towards each other from substantially opposite directions. According to the present invention the problem is solved by providing a number of frequency bands ("channels") and a method whereby each radar or sonar automatically selects the appropriate channel for minimum interference, in accordance with the direction in which its beam is pointing. In one embodiment of the invention there are four channels, common to all the installations and corresponding to the four principal directions of the compass. A data link 6 from compass direction determining device 8 to radar 5 ensures that whenever the antennas of two installations point towards each other, the installations always use different channels, thereby solving the problem. |
