Accession Number : AD0784854

Title :   Consideration of Near Field Effects in Microwave Landing System (MLS) Feasibility Evaluation,


Personal Author(s) : Marsh,H. S.

Report Date : JUL 1974

Pagination or Media Count : 35

Abstract : The near field MLS beam pattern may be troublesome if C-band flare guidance is used. One of the complications is introduced by defocusing or broadening of the beam received by an aircraft located in the near field of the antenna. With a C-band flare elevation subsystem, the antenna near field will extend a distance from the antenna sufficient to contain the aircraft during flare and touchdown, and so the precise characteristics of the near field signals must be understood. The effects of beam broadening on system accuracy and signal processing requirements are briefly examined, and experimental investigations are recommended. A short discussion of antenna aperture optimization is also presented, and parallels are drawn between Doppler MLS and synthetic aperture radar. (Author)

Descriptors :   *Landing aids, Microwave equipment, Near field, Antenna apertures, Optimization, Beam forming, Feasibility studies

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE