Harold T. Dougherty and Burgette A. Hart

Abstract: This report presents some estimates of the enhanced fields deduced from the presently available theory and observational data. The fields of interest are the enhanced fields that are encountered in the presence of the stratified atmosphere, the ducting conditions associated with supercritical refractivity gradients both near the surface and aloft. As a basis for estimating the likelihood of occurrence of these supportive conditions, the available information is surveyed. It is suggested that the access to computers and the availability of historical radiosonde data be exploited and the pertinent characteristics of elevated layers and their associated ducts be mapped on a worldwide basis to meet the interference prediction requirements of regulatory agencies.

Keywords: interference; propagation; fading; anomalous propagation; radio signals; ducting

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

For questions or information on this or any other NTIA scientific publication, contact the ITS Publications Office at ITSinfo@ntia.gov or 303-497-3572.

Back to Search Results