The same author has an explainer of Sporadic-E and skywave propagation here: https://www.radioworld.com/columns-and-views/double-hop-dreams-and-the-mystery-of-

The same author has an explainer of Sporadic-E and skywave propagation here: https://www.radioworld.com/columns-and-views/double-hop-dreams-and-the-mystery-of-long-distance-fm https://www.radioworld.com/columns-and-views/double-hop-drea...