Auroral Large Imaging System, ALIS
Article on propagation basics. The ground wave used for radio communications signal propagation on the long, and medium wave bands for local radio communications
Meteor Shower, Aurora, Sporadic-E and Solar Flares detected using Radio Signal Reflection, by Andy Smith, G7IZU. Live waterfall displays from three receivers, live Es propagation maps.
By Ken Larson KJ6RZ, a complete guide to understanding soloar indices and values.
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
This is a highly informative map that can be used by amateur and professional radio communicators to determine maximum usable frequencies for any world-wide path at the indicated UTC (Zulu) time.
Current Solar Wind Conditions
Daily sun spots data collected by the Catania astrophysical observatory
Amateur projects to investigate radiowave propagation - G3PLX\'s chirp project, ionosonde database, and more
Live space weather and propagation data, in RSS (XML) format.
Long path hf radio propagation is sometimes the best path to work dx, since the shortest path is not always the best path.
NVIS definition at Wikipedia
WM5R presentation of Introduction to Long-delaye echoes and theories among this propagation effect.
Website dedicated to vhf radio aurora operations by KG0VL
This is a propagation prediction program tailored to the serious contester
This map can be used to determine the frequencies that will always be returned to the Earth. Transmitted frequencies higher than the indicated contours (which are given in MHz) may penetrate the ionosphere, resulting in lost power to space.
The map shows the radio auroral zones as green bands near the northern and southern poles.
Sun obserevatory in Catania Italy offer daily sun reports
NOAA / Space Weather Prediction Center, Geomagnetic K-indices and Running A-indices, Local Noon Solar Radio Flux, Daily Solar Indices with SSN
Solar Region Data Current Regions with Sunspots Summary, an useful tool for predictions
About the band behaviour or propagation towards distant locations by SM6EHY