The present invention relates to an aircraft radar receiver for search and for tracking a target through one or more telemetry windows which, in the search phase, carry out distance scanning and which, on receiving a target echo, locks onto the same in order to supply telemetric information, said receiver comprising means for, during the search phase, desensitizing the radar receiver for the distance which corresponds to the altitude of the aircraft above the ground so that the altitude return signal does not cause the radar to switch to tracking state, wherein the desensitization means are inoperative when the altitude return signal occurs in the radar tracking state.