Abstract: A target classification method for radar systems wherein, in particular, jet aircraft, are classified in that the blade repetition rate and, in a further step, the number of blades, of an engine rotor wheel are determined and thus the type of engine is identified. Helicopters are classified by determining the blade repetition period of the primary or tail rotor.

Abstract: In an aircraft on-board radar system employing a sharply focused directional pattern which is able to sweep over a given space range, the range in the MPRF mode is limited primarily by the ground clutter picked up via the side lobes of the antenna pattern. To increase the range, an antenna is employed which, due to asymmetrical distribution of the antenna aperture (signal field) in the elevational direction with respect to the center of the aperture, has a significantly higher side lobe spacing below the principal lobe than above the principal lobe. Because of the side lobe spacing being greater below the principal lobe, less ground clutter components are picked up while the smaller side lobe spacing above the principal lobe results in hardly any increase of clutter components in the echo signal.