Measurements and Analysis of Ducting and Anomalous Propagation Over Land
Abstract
Current models for radio propagation used by the Navy are 2D vertical plane models that are designed for over-water paths and incorporate the associated atmospheric effects. However, in littoral or over-land environments, terrain diffraction and out-of-plane multipath are first-order contributors to RF propagation. The contribution of atmospheric effects over land is intermittent and generally more noticeable on longer-distance paths. These contributions depend on the path geometry and terrain interactions. Studies ofpropagation along these long-distance over-land paths # and which explicitly address terrain, foliage, and atmospheric effects # are not sufficiently well addressed in the published literature. To this end, the Naval Research Laboratory (NRL) has formed a collaboration with the University of Utah, HS Owen LLC, and Virginia Tech to address this problem. The role of Virginia Tech will be primarily to conduct propagation measurements and reduce data to products # including rigorously-documented examples of anomalous propagation # which can then be used by NRL to examine existing models, and by the University of Utah to develop and refine new models. Virginia Tech will perform a comprehensive campaign of measurements and analysis to characterize RF propagation over land with a focuson conditions and environments that would be expected to create anomalous propagation, including ducting. Primary sources will be existing high-power transmitters # so-called #signals of opportunity# (SoO) # with additional measurements from project-controlled transmitters for validation purposes and when greater control over the measurement conditions is desired. Outcomes include: (1) Curated datasets obtained from rigorous measurements of over-land propagation; (2) Reduction of these datasets to data products suitableto facilitate the work of NRL and the University of Utah (i.e., model development, analysis, and validation); and (3) At Virginia Tech, analysis of these data products specifically to identify and quantify instances of anomalous propagation.The proposed work willimprove the Navy#s propagation prediction tools and specifically will enhance the Navy#s ability to predict anomalous propagation events over land. This will allow for more effective mission planning, better understanding of the performance of radar and tacticalradio systems, better EMCON, and more effective asset deployment.Approved for public release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 09, 2024
- Source ID
- N000142412725
Entities
People
- Steven Ellingson
Organizations
- Office of Naval Research
- United States Navy
- Virginia Tech