A METHOD OF PREVENTING A RADAR BEACON FROM RESPONDING TO RECEIVED RADAR PULSES ORIGINATING FROM THE SIDE LOBES OF A TRANSMITTER AND AN ARRANGEMENT TO CARRY OUT THE METHOD

摘要

PCT No. PCT/SE80/00325 Sec. 371 Date Jul. 17, 1981 Sec. 102(e) Date Jul. 17, 1981 PCT Filed Dec. 8, 1980 PCT Pub. No. WO81/01747 PCT Pub. Date Jun. 25, 1981.A method for preventing a radar beacon's response 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 when 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 such signals is measured and a corresponding value is stored. Measuring two subsequent and equal carrier frequencies is considered as a criterion that a response signal from the beacon responding to the second received signal should not be transmitted. An arrangement to carry out the method is described.