Accession Number : ADA320254

Title :   Multipath Modelling for Terrestrial VHF Radio Direction Finding,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)

Personal Author(s) : Read, William

PDF Url : ADA320254

Report Date : DEC 1996

Pagination or Media Count : 108

Abstract : This report details the development of computer models to investigate and explain the effects of multipath on VHF radio direction finding (DF). The motivation for this development was to help explain the large and small scale multipath effects which occur for changes in transmitter and receiver position, or for changes in frequency. Particularly important in the analysis of current wide and narrow band DF approaches and the development of better ones. The new approach is based on representing the terrain and vegetation, which effect the signal path, by a large number of small (relative to the signal wavelength) isotropic reradiators. Polarization effects are not accounted for. Although this kind of approach can quickly become a computationally daunting task, a number of simplifications are introduced which greatly simplify the calculations. Two examples have been included illustrating the use of the proposed approach in the analysis and modelling real world measurements.

Descriptors :   *RADIO DIRECTION FINDERS, COMPUTERIZED SIMULATION, CANADA, RADIO RECEIVERS, BEAM FORMING, ANTENNA ARRAYS, VERY HIGH FREQUENCY, MULTIPATH TRANSMISSION, NARROWBAND, MULTICHANNEL.

Subject Categories : Direction Finding

Distribution Statement : APPROVED FOR PUBLIC RELEASE