surface wave or a ground wave can refer to a mechanical wave that propagates along the interface between differing media, usually two fluids with different densities. A surface wave can also be an electromagnetic wave guided by a refractive index gradient. In radio transmission, a ground wave is a surface wave that propagates close to the surface of the Earth.
sky wave : Sky waves are reflections from the ionosphere.
Skywave is the propagation of radio waves bent (refracted) back to the Earth's surface by the ionosphere. As a result of skywave propagation, a night-time broadcast signal from a distant AM broadcasting or shortwave radio station (or rarely, a TV station) can sometimes be heard as clearly as local stations. Most long-distance HF radio communication (between 3 and 30 MHz) is a result of skywave propagation. For decades Amateur radio operators, limited to lower transmit power than commercial radio, have taken advantage of skywave for distance or DX communication.
You have rated this answer /10
- Biology Question Answers for CBSE Class 12 Science
- Chemistry Question Answers for CBSE Class 12 Science
- Economics Question Answers for CBSE Class 12 Science
- Hindi Question Answers for CBSE Class 12 Science
- Mathematics Question Answers for CBSE Class 12 Science
- Physics Question Answers for CBSE Class 12 Science