Main Page | See live article | Alphabetical index In telecommunication, ground constants are the electrical parameters of earth, such as conductivity, permittivity, and magnetic permeability. The values of these parameters vary with the local chemical composition and density of the earth. For a propagating electromagnetic wave, such as a surface wave propagating along the surface of the Earth, these parameters vary with frequency and direction. See also: Ground Source: from Federal Standard 1037C and from MIL-STD-188 This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.