| 摘要 |
<p>A method to prevent a radar beacon respond to received pulses from a vessel which originate from the side lobes of the vessel antenna. The carrier frequency of the radar signal pulses to and received by the beacon is measured and a value of this frequency is stored in the case that the amplitudes of the signal pulses exceed a certain high threshold level (Th). If signals after that are received which exceed a low threshold level (Tl) (but not the high) the carrier frequency of these is measured and the corresponding value is stored. Measuring two subsequent and equal carrier frequencies is considered as a criterion that a responding signal from the beacon responding to the second received signal should not be transmitted. An arrangement to carry out the method is described. </p> |
