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.
For the standard atmosphere, the effective Earth radius is 4/3 that of the actual Earth radius. The ratio of the effective Earth radius to the actual Earth radius is called the k factor.
Famous quotes containing the words effective and/or earth:
“[Humanity] has unquestionably one really effective weapon—laughter. Power, money, persuasion, supplication, persecution—these can lift at a colossal humbug—push it a little—weaken it a little, century by century; but only laughter can blow it to rags and atoms at a blast. Against the assault of laughter nothing can stand.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“War was return of earth to ugly earth,
War was foundering of sublimities,
Extinction of each happy art and faith
By which the world had still kept head in air.”
—Robert Graves (1895–1985)