off-surface antenna
11Omnidirectional antenna — The radiation pattern of a simple omnidirectional antenna, a vertical half wave dipole antenna. In this graph the antenna is at the center of the donut . Radial distance from the center represents the power radiated in that direction. The power… …
12Crossed field antenna — A crossed field antenna, or CFA, is a type of antenna for long and mediumwave broadcasting, patented in 1986, which was claimed to have the same efficiency as a conventional antenna but only one tenth the overall height. The invention was… …
13Apollo Lunar Surface Experiments Package — The Apollo Lunar Surface Experiments Package (ALSEP) comprised a set of scientific instruments placed by the astronauts at the landing site of each of the five Apollo missions to land on the Moon following Apollo 11 (Apollos 12, 14, 15, 16, and… …
14radio telescope — Astron. a system consisting of an antenna, either parabolic or dipolar, used to gather radio waves emitted by celestial sources and bring them to a receiver placed in the focus. [1925 30] * * * Combination of radio receiver and antenna, used for… …
15Mars Exploration Rover — Artist s conception of rover on Mars Part of a panorama taken by the Spi …
16telescope — /tel euh skohp /, n., adj., v., telescoped, telescoping. n. 1. an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens… …
17electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …
18Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
19telecommunications media — Introduction equipment and systems metal wire, terrestrial and satellite radio, and optical fibre employed in the transmission of electromagnetic signals. Transmission media and the problem of signal degradation Every… …
20Ship gun fire-control system — Mk 37 Director c1944 with Mk 12 (rectangular antenna) and Mk 22 orange peel Ship gun fire control systems (GFCS) enable remote and automatic targeting of guns against ships, aircraft, and shore targets, with or without the aid of radar or optical …
