MONITORING SYSTEM FOR SCANNING-BEAM MICROWAVE LANDING APPARATUS

摘要

G. Hofgen - 28 MONITORING SYSTEM FOR SCANNING-BEAM MICROWAVE LANDING APPARATUS Monitoring apparatus for a time reference scanning-beam microwave landing system which supplies directional information throughout a 40.degree. to60.degree. landing approach sector. Several transponders are provided within the radiation field of the directional antenna of the landing system, these being directionally separated. Each transponder retransmits a part of the beam passing by it back to the directional antenna of the microwave landing system. The retransmitted signals are in converted form and are processed by the MLS system similar to radar echo signals, but are modulated at different discreet frequencies for identification. Errors are detected by comparing received transponder signals with locally generated reference signals at the MLS equipment.