appleton layer   (TTS Sound)

The appleton_layer has 1 Senses.

• f region, f layer, appleton layer
• the highest region of the ionosphere (from 90 to 600 miles up) which contains the highest concentration of free electrons and is most useful for long-range radio transmission
• 電離圏の一番高い所（上空90マイルから600マイル）で、自由電子の密度が最も高く、長距離の無線伝達に最も便利