Radarantennenanordnung

A radar arrangement has a transmitter/receiver unit which is rotatable and has an aerial projecting an elongate radar beam onto a reflector which rotates therewith. The reflected beam therefore scans the target area. Target reflections are reflected by the reflector on to the aerial for detection thereby. The reflector is switchable about the vertical axis through 90 DEG with respect to the aerial. In one position, the beam is therefore projected into, and scans, the target area with its elongate dimension vertical (so as to be best suited to detect rapidly approaching targets of small aspect such as aircraft or missiles), and in the other position the beam is projected into, and scans, the target area with its elongate dimension horizontal (so as to be best suited to detect intermittent targets appearing in relatively slow moving positions such as the rotor blades of a helicopter).