Domanda 123, Comunicazioni in inglese - PPL(A) - Licenza Pilota Privato (Aerei)

The waves are reflected at the ionosphere at the height of about 100 km and reach the earth surface in the form of skywaves
The waves travel along the surface of the earth and penetrate into valleys in a way that topographical obstacles have no influence
Similar to short waves with practically no atmospheric disturbance
Practically straight-line similar to light waves