ionospheric layer
71Radio broadcasting — Long wave radio broadcasting station, Motala, Sweden …
72Solar cycle — The solar cycle, or the solar magnetic activity cycle, is the main source of periodic variation of all solar phenomena driving variations in space weather. [ [http://www7.nationalacademies.org/ssb/SSB Space weather97.pdf Space Weather: A Research …
73Ronald N. Bracewell — Infobox Scientist name = Ronald N. Bracewell box width = image width = caption = birth date = Birth date|1921|07|22 birth place = Sydney, New South Wales, Australia death date = Death date and age|2007|08|12|1921|07|22 death place = Stanford,… …
74Meteor burst communications — Meteor scatter propagation as used by SNOTEL Meteor burst communications (MBC), also referred to as meteor scatter communications[1], is a radio propagation mode that exploits the ionized trails of meteors during atmospheric entry to establish… …
75Amateur radio frequency allocations — Amateur radio frequency allocation is done by national telecommunications authorities. Globally, the ITU oversees how much radio spectrum is set aside for amateur radio transmissions. Radio amateurs use a variety of transmission modes, including… …
76List of environmental topics (S) — This is a list of environmental topics. They relate to the effect of human activity on the environment.*saline seep *salinity in Australia *salting the earth *School of Environmental Studies *Science Environmental Policy Project *Scientific… …
77List of astronomy acronyms — This is a compilation of acronyms commonly used in astronomy. Most of the acronyms are drawn from professional astronomy and are used quite frequently in scientific publications. However, a few of these acronyms are frequently used by the general …
78HRS antenna — HRS type antennas are more or less the standard antenna used for long distance high power shortwave broadcasting (> 1000 km). Contents 1 History of HRS design 2 Nomenclature 3 A versatile antenna type …
79Multipath propagation — This article is about the electromagnetic propagation phenomenon. For the computing storage term, see Multipath I/O. For the routing term, see Multipath Routing. In wireless telecommunications, multipath is the propagation phenomenon that results …
80ionosphere — [ʌɪ ɒnəsfɪə] noun the layer of the atmosphere above the mesosphere, which contains a high concentration of ions and electrons and is able to reflect radio waves. Derivatives ionospheric adjective …
