Ground-penetrating radar — (GPR) is a geophysical method that uses radar pulses to image the subsurface. This non destructive method uses electromagnetic radiation in the microwave band (UHF/VHF frequencies) of the radio spectrum, and detects the reflected signals from… … Wikipedia
Ground (electricity) — In electrical engineering, ground or earth may be the reference point in an electrical circuit from which other voltages are measured, or a common return path for electric current, or a direct physical connection to the Earth. A typical earthing… … Wikipedia
Ground dipole — A Ground dipole, or Ground antenna, is a special type of antenna which consists of two electrodes positioned in the ground.=Description=Ground dipole antennas are usually used for transmitting and receiving on the ELF and VLF bands. The antenna… … Wikipedia
Ground-coupled heat exchanger — Earth cooling tubes or earth warming tubes (also known as ground coupled heat exchangers) utilize the earth s near constant subterranean temperature to warm or cool air for residential, agricultural or industrial uses. They are often a viable and … Wikipedia
Ground constants — 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… … Wikipedia
Hydraulic conductivity — Hydraulic conductivity, symbolically represented as K, is a property of vascular plants, soil or rock, that describes the ease with which water can move through pore spaces or fractures. It depends on the intrinsic permeability of the material… … Wikipedia
Exhumation of Yagan's head — The exhumation of Yagan s head was the result of a geophysical survey and archaeological dig at a grave site in the Everton Cemetery, Liverpool in 1997.BackgroundYagan was an indigenous Australian warrior of the Noongar nation who played a key… … Wikipedia
Medium wave — Main article: Medium frequency Medium wave (MW) is the part of the medium frequency (MF) radio band used mainly for AM broadcasting. For Europe the MW band ranges from 526.5 kHz to 1606.5 kHz[1] and in North America an extended MW… … Wikipedia
Lightning rod — A lightning rod (USA) or lightning conductor (UK) is a single component in a lightning protection system. In addition to rods placed at regular intervals on the highest portions of a structure, a lightning protection system typically includes a… … Wikipedia
Geomagnetically induced current — Geomagnetically induced currents (GIC), affecting the normal operation of long technological conductor systems, are a manifestation at ground level of space weather. During space weather events (or geomagnetic storms) Earth s near space current… … Wikipedia
