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Propagation of RF Signals

Introduction

Radio waves, like light waves and all other forms of electromagnetic radiation, normally travel in straight lines. Obviously this does not happen all the time, because long - distance communication depends on radio waves traveling beyond the horizon. How radio waves propagate in other than straight-line paths is a complicated subject, but one that need not be a mystery. This page provides basic understanding of the principles of electromagnetic radiation, the structure of the Earth's atmosphere and solar-terrestrial interactions necessary for a working knowledge of radio propagation. More detailed discussions and the underlying mathematics of radio propagation physics can be found in the references listed under additional resources.

The Sun, being the largest engine in our solar system, has a great effect on propagation as its "exhaust" interacts with our Earth's magnetic field. A rudimentary knowledge of sunspots, solar flares and mass ejections will help the amateur take advantage of these effects to enhance his pleasure, or understand his plight.

Articles

Tutorials

 

Propagation Reports and Forecasts

  • Radio Signal Propagation
    Many articles on how radio signals travel great distances at different frequencies. Topics include sporadic E, sunspots, troposcatter, meteor scatter, sudden ionospheric disturbances, and ground wave propagation.
  • hfradio.org propagation
    This page is dynamically created from many sources using automation, and the information contained is as fresh as possible. This page will reload every 15 minutes, which will refresh any content that has changed since last viewing.
  • W1AW Propagation Bulletins W1AW, the Hiram Percy Maxim Memorial Station provides informational bulletins to Amateur Radio Operators.
  • DX-Listeners' Club Solar Terrestrial Activity Report
    The Solar Terrestrial Activity Report is generally updated once a day. The report contains a graphical view of the last 2 months' solar flux values, sunspot count and planetary A index. In addition there is information on recent solar events as well as predictions for the next days. Charts of all sunspot cycles from cycle 1 are available as well as comparisons of the most recent cycle with previous cycles
  • D-Region Absorption Prediction
    Presented by the NOAA/Space Environment Center
  • Today's Space Weather
  • Welcome to The Aurora Page
    Information, forecasts, links and images about the "Northern Lights".
  • VHF / UHF Tropospheric Ducting Forecast
  • Paul Kelley N1BUG maintains Aurora Sentry, a page with satellite maps that show auroral activity
  • VOACAP.com Monthly point to point and coverage area predictions for HF propagation.

Propagation Beacons

Propagation Software

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