Accession Number : ADP005423

Title :   Results of Numerical and Physical Modelling of Airborne Adcock Arrays for VHF DF (Direction Finding) Applications,

Corporate Author : COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH PRETORIA (SOUTH AFRICA)

Personal Author(s) : Baker,D. C. ; Botha,L. ; McNamara,D. A. ; Reed,G. W.

Report Date : FEB 1987

Pagination or Media Count : 31

Abstract : This paper describes an attempt to predict the received voltages on a VHF direction finding (DF) array using the geometrical theory of diffraction and the principle of reciprocity. Once the received voltages are known bearing errors can be predicted from the phase information. The predicted receive mode radiation patterns are compared with a simple model of a C130 Hercules transport aircraft. Further comparison is made with models representing a low-wing jetliner with underwing engines. The latter aircraft models use either a blunt capped cylinder or a sectional cylinder with a emispherical cap and a conic section. The comparison between predicted and measured results are reasonable.

Descriptors :   *ANTENNA ARRAYS, *DIRECTION FINDING, NUMERICAL ANALYSIS, ANTENNA RADIATION PATTERNS, VERY HIGH FREQUENCY, TRANSPORT AIRCRAFT, ERRORS, ACCURACY

Subject Categories : Direction Finding
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE