Aircraft radar system - has spectrum analyser which is switched OFF during tracking and switched ON to give distance precision when target is in close range

摘要

The aircraft radar has a spectrum analyser. The spectrum analyser is switched so that in a first condition the circuit at its output provides data which permits detection of a target. Ground or parasitic echoes and noise signals are excluded. Presence of the target echo transfers the radars supervisory circuit from a matching mode to a tracking mode. A second switching is made to bring the radar system into its tracking mode. The spectrum analyser can then be used to protect against parasitic echoes or noise signals. A final switching is carried out when the aircraft is near the target so as to bring the system into a condition in which distance data is again provided from the spectrum analyser with increased precision.