What is the term for radio waves scattering in the troposphere, allowing communication beyond the horizon?

Tropospheric scattering refers specifically to the phenomenon where radio waves are scattered in the troposphere, which is the lowest layer of the Earth's atmosphere. This scattering enables radio signals to travel beyond the typical line of sight, allowing communication to occur even when the transmitting and receiving antennas are not in a direct path from one another.

In this process, radio waves encounter irregularities in the atmosphere, such as variations in temperature and humidity, which cause the waves to bend and scatter. This is particularly useful for frequencies in the UHF and microwave range, as they can effectively utilize tropospheric scattering for long-distance communication, especially over the horizon.

In contrast, other terms like sky wave propagation refer to waves that are reflected off the ionosphere, and ground wave dispersion pertains to waves that travel along the surface of the Earth. Multipath transmission involves the reception of multiple signals that may arrive at slightly different times due to reflections off various surfaces, but it does not specifically address the phenomenon of scattering in the troposphere. Therefore, tropospheric scattering is the most accurate term related to the ability to communicate beyond the horizon due to atmospheric conditions.