Implementation of the Numerical Electromagnetic Code (NEC-2) for Modeling the VOR (Very-High-Frequency Omni-Directional Range) Navigation System in the Presence of Parasitic Scatterers

Abstract

A computer model has been developed that estimates bearing error for a VOR airborne navigation system operating in the presence of small, parasitic scatterers such as antennas, antenna masts, and guy wires. This model, which is written using FORTRAN 77, interacts with an unmodified version of the Numerical Electromagnetics Code (NEC-2) to obtain the pertinent scattered-field data. These data are then used to calculate the composite field, and indicated bearing, at the airborne receiver location. Modeled results consist of plots of bearing error versus 'true' bearing. Comparisons of modeled and measured data are presented. The azimuth angle of an aircraft with respect to a VOR station is determined by the phase of the received audio sinusoid generated by a limacon radiation pattern that rotates in space due to appropriate time varying phasing between four Alford loop antennas.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jun 13, 1986
Accession Number
ADA170669

Entities

People

  • Paul R. Barre

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aircrafts
  • Antenna Radiation Patterns
  • Antennas
  • Coordinate Systems
  • Electromagnetic Fields
  • Electromagnetic Radiation
  • Far Field
  • Fast Fourier Transforms
  • Frequency
  • Frequency Bands
  • Guy Wires
  • Navigation
  • Radiation
  • Radiation Patterns
  • Radio Ranges (Transmitters)
  • Shape
  • Very High Frequency

Readers

  • Aviation Safety and Air Traffic Management
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Phased Array Antenna Design.

Technology Areas

  • Space