Effective Earth radius
Encyclopedia
In telecommunication
, effective Earth radius is the radius of a hypothetical Earth
for which the distance to the radio horizon, assuming rectilinear propagation
, is the same as that for the actual Earth with an assumed uniform vertical gradient of atmospheric refractive index
.
Note: For the standard
atmosphere, the effective Earth radius is 4/3 that of the actual Earth radius
.
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
, effective Earth radius is the radius of a hypothetical Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
for which the distance to the radio horizon, assuming rectilinear propagation
Wave propagation
Wave propagation is any of the ways in which waves travel.With respect to the direction of the oscillation relative to the propagation direction, we can distinguish between longitudinal wave and transverse waves....
, is the same as that for the actual Earth with an assumed uniform vertical gradient of atmospheric refractive index
Refractive index
In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....
.
Note: For the standard
Standardization
Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....
atmosphere, the effective Earth radius is 4/3 that of the actual Earth radius
Earth radius
Because the Earth is not perfectly spherical, no single value serves as its natural radius. Distances from points on the surface to the center range from 6,353 km to 6,384 km...
.