VHF Propagation of Over Hilly, Forested Terrain

Abstract

We have made propagation measurements at low altitudes over hilly, forested terrain with the objective of developing a computer-based propagation model capable of predicting path loss given the terrain profile between transmitter and receiver. The measurements were made at a frequency of 110.6 MHz with the VOR station at Gardner, Massachusetts, as a transmitter. The received signal was measured at distances between 7 and 15 km by making vertical descents with a helicopter from altitudes of roughly 800 m down to 10 m above ground. We found good agreement between the measurements and model predictions based on an extension of the Deygout approximation. Use of two knife-edges was sufficient to characterize the terrain diffraction. Negligible multipath reflection was observed from this terrain.

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Document Details

Document Type
Technical Report
Publication Date
Apr 09, 1982
Accession Number
ADA115746

Entities

People

  • M. L. Meeks

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Agreements
  • Altitude
  • Computer Programs
  • Computers
  • Diffraction
  • Elevation
  • Frequency
  • Fresnel Zones
  • Helicopters
  • Line Of Sight
  • Low Altitude
  • Measurement
  • Navigation
  • Radio Navigation
  • Radio Ranges (Transmitters)
  • Reflection
  • Transmitters

Fields of Study

  • Physics

Readers

  • Astronomy and Astrophysics.
  • Computational Modeling and Simulation
  • Urban Planning and Geography.