ALL meanings of f layer
f lay·er
F f - noun f layer the highest of the radio-reflective ionospheric layers, beginning at an altitude of about 80 miles (130 km) and consisting of two parts, the lower part (F layer) being detectable in the daytime only, the higher (F layer or Appleton layer) being constant and constituting the ionospheric layer most favorable for long-range radio communication. 1
- noun f layer the two dense layers of ions in the F region of the ionosphere that are used to reflect long-range radio signals: the F1 layer, at an altitude of c. 200 to 300 km (c. 125 to 185 miles), exists during the day, and the permanent F2 layer, or Appleton layer, is at c. 225 to 400 km (c. 140 to 250 miles) 0