Extension of a portable tactical instrument approach and landing system

MADGE III, Microwave Aircraft Digital Guidance Equipment, is a logical extension of MADGE I which won the NATO portable tactical instrument approach and landing system competition last year. The system concept can be summarised as a combined distance‐measuring data‐link equipment in the aircraft which interrogates the ground terminal with an address code and a data message which includes information, such as distance, and air speed, such as may be necessary on the ground. Angles are measured on this transmission and the ground terminal transponds with a standard message carrying angular, cartesian or displacement data as required. Routine airfield status and air traffic control information may also be transmitted in the standard message format.