As promised, the following links and references should get you started on exploring the topics I mentioned during my “Propagation 101” presentation at the April 20, 2017 SARA meeting.  Please let me know if you find other sites of interest.
zeke, AB8OU
Click here to download Propagation-101.pdf Presentation Slides.
NOAA Space Weather Prediction Center
- Space Weather Enthusiasts Dashboard
- HF Radio Communications
- D-Region Absorption Prediction Product Archive
NASA
Ionospheric Sounding
- Background to Ionospheric Sounding
- Ionosphere Program at NCEI
- DIDBase Fast Station list
- Interpreting Disital Ionograms – RADCOM, May 2009
- Gimme an X, Gimme an O, What’s that Spell? – Radio, Eric Nichols, KL7AJ, QST, December 2010, page 33. (Available to ARRL members in the ARRL Periodicals Archive)
Contest University Files
- W3LPL:Â Adapting Your contesting Strategies to the Rapidly Declining Solar Cycle 24Â (PPTX)
- W3LPL: Improving Your 160 and 80 Meter Antennas for the Declining Solar Cycle (PPTX)
- W3LPL: Improving Your 40 through 10 meter Antennas for the Declining Solar Cycle (PPTX)
- W3LPL:Â Propagation Trends for 2014-15Â (PPTX)
K9LA’s Propagaqtion Website
- K9LA’s Amateur Radio Propagation Web Site
- NM7M The Big Gun’s Guide to Low-Band Propagation
- NM7M The Little Pistol’s Guide to HF Propagation
- Physics of Propagation – Refraction Absorption Polarization
Other Web Sites
- Solar Ham
- Space Weather
- CONUS HF Band Conditions
- Solar Cycle Science  (Under Development)
- Leif Svalgaard’s Research Page
- Australian Space Weather Services – HF Systems
- RSGB ITURHFProp Propagation Prediction
- Sun Spot Watch
- G4FKH HF Ionospheric Propagation Articles
- NWRA Space Weather Indices
Books
- Propagation and Radio Science, Eric Nichols, KL7AJ, May 11, 2015 by ARRL Inc.
- The ARRL Antenna Book: The Ultimate Reference for Amateur Radio Antennas, Transmission Lines And Propagation (Arrl Antenna Book), May 1, 2007, by American Radio Relay League and R. Dean Straw