The merits of using a large gradient antenna in the ground station of a conventional VOR system are theoretically investigated. A theory has been developed for the course amplitude scalloping errors in the bearing indications of a conventional VOR system. The theory takes into account the vertical plane pattern of the transmitting antenna and the scattering properties of the multipath sources. The vertical plane patterns of conventional VOR and large gradient antennas located above ground are studied in detail. Observed scalloping amplitudes for antennas located at variable height and with isolated isotropic multipath sources located at various distances from the antennas and at variable height above ground are calculated and compared with each other. It has been found that in certain difficult siting conditions the large gradient antennas reduce considerably the scalloping errors. Extensive curves are plotted so that problems associated with siting problems in conventional VOR may be studied.

  • Corporate Authors:

    University of Michigan, Ann Arbor

    Radiation Laboratory
    Ann Arbor, MI  United States  48104

    Federal Aviation Administration

    800 Independence Avenue, SW
    Washington, DC  United States  20591
  • Authors:
    • Sengupta, D L
  • Publication Date: 1974-8

Media Info

  • Pagination: 137 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00090154
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: Final Rpt.
  • Contract Numbers: DOT-FA72WA-2882
  • Files: NTIS, USDOT
  • Created Date: Apr 22 1975 12:00AM