Definitions for "F Region"
The upper layer of the ionosphere, approximately 120 to 1500 km in altitude.
the highest region of the ionosphere (from 90 to 600 miles up) that contains the highest concentration of free electrons and is most useful for long-range radio transmission
The lowest layer of the Earth's ionosphere. It is between about 160 and 400 kilometers above Earth's surface. Also called the F Layer. more