radio-frequency electromagnetic sounding
1Extremely high frequency — Frequency range 30 to 300 GHz ITU Radio Band Numbers 1 2 3 4 5 6 7 8 9 10 …
2List of radio propagation topics — This is a list of radio propagation terms. NOTOC A a index A index aa index active prominence active prominence region (APR) active region active surge region (ASR) active dark filament (ADF) AE index Air Force Geophysics Laboratory (AFGL) arch… …
3List of electronics topics — Alphabetization has been neglected in some parts of this article (the b section in particular). You can help by editing it. This is a list of communications, computers, electronic circuits, fiberoptics, microelectronics, medical electronics,… …
4telescope — /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… …
5space exploration — Investigation of the universe beyond Earth s atmosphere by means of manned and unmanned spacecraft. Study of the use of rockets for spaceflight began early in the 20th century. Germany s research on rocket propulsion in the 1930s led to… …
6Measuring instrument — Captain Nemo and Professor Aronnax contemplating measuring instruments in Twenty Thousand Leagues Under the Sea …
7star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …
8List of cycles — This article does not deal with types of bicycles, for that see Bicycle#Types and Category:Cycle types. This is a list of recurring cycles. See also list of wave topics, time, and pattern. Contents 1 Time and calendar cycles 2 Planetary cycles …
9Earth exploration — Introduction the investigation of the surface of the Earth and of its interior. By the beginning of the 20th century most of the Earth s surface had been explored, at least superficially, except for the Arctic and Antarctic regions. Today the… …
10Doppler effect — Change of wavelength caused by motion of the source. An animation illustrating how the Doppler effect causes a car engine or siren to soun …
