
	Where results make sense

Topic: Tropospheric scatter

Related Topics

Troposphere

Radio propagation

Electromagnetic spectrum

Shetland Isles

1890 in architecture

Glasgow School of Art

1891 in architecture

1897 in architecture

Pollution

1949 in architecture

Rick Santorum

1957 in architecture

Santorum controversy

Florence

2002 in architecture

	Tropospheric scatter - Wikipedia, the free encyclopedia
		Tropospheric scatter (or troposcatter) is the scattering of distant TV and FM radio stations by the troposphere so that they travel farther than the line of sight.
		Large billboard antennas focus a high power radio beam at the troposphere mid-way between the transmitter and receiver.
		A certain proportion of the signal is reflected and received at a similar antenna at the receiving station.
	en.wikipedia.org /wiki/Tropospheric_scatter (232 words)

	Tropospheric DX Modes
		Scatter is caused by small particles/droplets in the air such as haze, dust, volcanic ash, clouds, etc.
		Also..weaker tropo scatter stations that are normally not heard (because their signal strengths never cross the background noise threshold signal level) also begin to appear.
		Ionospheric "skip" and scatter are not caused by the weather..but instead by the interaction between the Sun and the Earth's outer atmosphere..or by objects such as meteors.
	www.dxinfocentre.com /propagation/tr-modes.htm (1424 words)

	An Investigation into Tropospheric Propagation at 50MHz
		This means that in the case of ‘true’ scattering at 50 MHz, the volume ‘illuminated’ by the transmitting and receiving antennas would be so wide in a horizontal plane that beams would lose their sense of directivity.
		In order to refract a VHF radio wave of a given wavelength from the troposphere down towards the receiving antenna, key factors are the source of heating and its distribution through the atmosphere and the available moisture and the relative moisture content of adjoining volumes of air.
		Tropospheric propagation depends on radiation from the sun, but the atmosphere absorbs very little heat directly from solar radiation so that it penetrates and heats the surface of the earth, causing it to re-radiate heat at a lower frequency.
	www.uksmg.org /Investigation.htm (4761 words)

	UHF TV-DX and fringe reception techniques
		Tropospheric propagated signals travel in the part of the atmosphere adjacent to the surface and extending to some 25,000 feet.
		Tropospheric ducting of UHF television signals is relatively common during the Summer and Autumn months, and is the result of change in the refractive index of the atmosphere at the boundary between air masses of different temperatures and humidities.
		The theoretical maximum distance that can be worked by tropospheric scatter is limited ultimately by the line of sight distance between the TV transmitter and receiving station have of the same scattering region of the troposphere.
	www.geocities.com /toddemslie/UHF-TV-DX.html (4954 words)

	[No title]
		Tropospheric scatter arises from radio waves being scattered by small cells of different refractive index in the atmosphere.
		Both the scattering angle and the height of scattering vary as a function of distance due to Earth curvature and horizon obstructions.
		Geometry of a tropospheric scatter path where D (or d) is the distance between the stations, qS is the scattering angle, q1 and q2 are the horizon angles at each station, and a1 and a2 are the beamwidths of the antennas.
	www.cq-vhf.com /Wint06CalculaTrop.html (478 words)

	Tropospheric Scatter Communication Network
		Tropospheric Scatter (also known as Tropo or Troposcatter.) was the method of communication chosen for the Pinetree Line radar stations which formed the 64th Air Division in the northeastern part of Canada during the 1950s and the early 1960s.
		Troposcatter relied on relatively high-powered transmitters and large high-gain "billboard antennas" to "bounce" signals off of particles in the troposphere which is the lowest layer of the atmosphere.
		The common volume was the area of the troposphere, up to about six miles above earth, where the beams from both sites, which had spread to cover a much larger area, converged.
	www.pinetreeline.org /misc/other/misc3a.html (681 words)

	TROPOSPHERIC SCATTERING
		This scattering mode of propagation enables vhf and uhf signals to be transmitted far beyond the
		The scatter volume and scatter angle are shown in figure 2-26.
		As the signal take-off angle is increased, the height of the scatter volume is increased.
	www.tpub.com /content/neets/14182/css/14182_97.htm (377 words)

	Tropospheric DX Modes
		A Tropo DX mode is any condition that scatters, reflects or refracts signals in the Troposphere allowing DX to occur.
		Distances are no different than your tropo scatter catches..it's just that the signals are stronger.
		So these are the conditions in the troposphere that allow reception of VHF and UHF signals beyond their normal range.
	home.cogeco.ca /~vem3ont22/propagation/tr-modes.htm (1449 words)

	MIT Lincoln Laboratory - Communication Systems
		Laboratory accomplishments in the field of communications include pioneering work in tropospheric scatter, digital data transmission, and error detection and correction techniques.
		Our pioneering work in tropospheric scatter, digital data transmission, error detection/correction, and optical transport techniques is world-renowned.
		In fact, many of the satellite and fiber-based communications used today derive from our technologies and developmental demonstrations.We are currently focused on identifying and demonstrating technologies that will be required in next-generation systems, as well as ensuring that our proven technologies are transferred to industry and integrated into operational communication systems.
	www.ll.mit.edu /programs/commsys.html (207 words)

	AMS Radiometeor Audio Gallery
		These tones are the tropospheric scatter signals from each of the transmitters closest to the receiver, with the receiver BFO adjusted for the most comfortable tone pitches.
		It will be noted that when more than one tropospheric scatter signal is present, the tones will usually be on different notes.
		Below this density, the electrons in the meteor trail scatter the radio wave independently, creating a received signal which rises very sharply when the meteor trail forms, but then rapidly decays exponentially as the trail diffuses.
	www.amsmeteors.org /audio/index.html (1223 words)

	Basics of Radio Wave Propagation
		However, meteor scatter contacts are usually more brief; and a result, APRS and VHF packet radio is considered to be a good means of communication during meteor showers due to the mode's short packets of data containing useful information such as the transmitting station's callsign as well as location in each packet sent.
		Tropospheric scatter: The only form of propagation that is directly influenced by the surface weather of the earth.
		Of the white-light corona (that is, the corona seen by the eye at a total solar eclipse), that portion which is caused by sunlight scattered by electrons in the hot outer atmosphere of the sun.
	ecjones.org /propag.html (16958 words)

	Tropospheric Scatter System
		The Tropospheric Scatter System would provide communications across the entire northern portion of North America.
		Construction began in the summer of 1954 on a UHF tropospheric scatter system called the "Pole Vault" system by communications men.
		This tropospheric system, completed a year later in 1955, ran from Pepperrell, NF to Frobisher Bay, NWT including all of the stations in between.
	www.pinetreeline.org /misc/misc3.html (505 words)

	Television interference (Co-channel reception) - Wikipedia, the free encyclopedia
		This is caused by the signals from two different TV transmitters (operating on the same frequency) arriving at the aerial input of the TV.
		This can be caused by tropospheric ducting (also known as Tropospheric scatter) which occurs during high pressure weather conditions.
		This is a diagram showing how a reflective situation such as sporadic E or a tropospheric duct can allow distant signals to travel to RX from the distant transmitter
	en.wikipedia.org /wiki/Television_interference_(Co-channel_reception) (215 words)

	Chapter 2 - Communications-Electronics 1962-1970
		These tropospheric scatter trunks would be advantageous since, unlike conventional microwave, which needs a line of sight between sets, they would pass over the vast distances of underpopulated, enemy-infested terrain to connect the major operations and population centers in the Republic of Vietnam north of Saigon.
		Although these large tropospheric scatter terminals, each of which was mounted in three large semitrailers, were designed for transportable operation, their 30-foot mobile antennas could not be used because of the relatively great path lengths.
		An additional mobile tropospheric scatter link was installed, connecting Ban Me Thuot in the Central Highlands to the small town of Gia Nghia in west central Vietnam near the famous Duc Lap Special Forces Camp.
	www.army.mil /cmh/books/Vietnam/Comm-El/ch1.htm (3321 words)

	scatter - Search Results - MSN Encarta
		sprinkling, shake, dusting, scattering, scatter, peppering, dash, smidgen
		Cluster bombs (sometimes called scatter bombs) house submunitions, smaller explosives contained in individual cases.
		The Lincoln Laboratory at South Dartmouth, Mass., has devised a radio signal system that makes continental defense against air attack possible.
	encarta.msn.com /scatter.html (186 words)

	AN/TRC-170(V)2 Tropospheric Scatter Microwave Radio Terminal
		The AN/TRC-170s are complete Tropospheric Scatter (TROPO) or Line Of Sight (LOS) terminals that include antennas, radio transmitting and receiving equipment, and digital multiplexing equipment.
		The AN/TRC-170(V)2 is a digital tropospheric scatter radio terminal which provides connectivity between two major nodes.
		Radio Frequency (RF) operation for both transmit and receive is in the 4.4 to 5.0 GHz frequency range with 3.5 or 7.0 MHz selectable bandwidth (3.5 MHz mode is used in Europe).
	www.fas.org /man/dod-101/sys/ac/equip/an-trc-170.htm (743 words)

	Hepburn Tropo Index
		"The Hepburn Tropo Index is the degree of tropospheric bending forecast to occur over a particular area..which is an indication of the overall strength of tropospheric radio signal strengths (and hence interference) on a linear scale from 0 to 10."
		Often if you are in a void but are still within line-of-sight or tropo scatter range of a nearby duct, then you may be able to get in on the duct - although signals will likely be weak.
		Unstable signal areas shown by areas enclosed with dotted lines labelled "U" are areas which may have isolated or scattered heavy rain showers or thunderstorms which could occasionally disrupt paths and cause unusual and sometimes rapid variations in signal strengths.
	www.dxinfocentre.com /propagation/hti.htm (466 words)

	Definition: tropospheric scatter (Site not responding. Last check: 2007-11-01)
		The propagation of radio waves by scattering as a result of irregularities or discontinuities in the physical properties of the troposphere.
		A method of transhorizon communications using frequencies from approximately 350 MHz to approximately 8400 MHz.
		(188) Note: The propagation mechanism is still not fully understood, though it includes several distinguishable but changeable mechanisms such as propagation by means of random reflections and scattering from irregularities in the dielectric gradient density of the troposphere, smooth-Earth diffraction, and diffraction over isolated obstacles (knife-edge diffraction).
	www.its.bldrdoc.gov /fs-1037/dir-038/_5617.htm (98 words)

	History Of the Phu Lam, Vietnam Signal Brigade
		It included an undersea cable from the Philippines to Nha Trang and a tropospheric scatter radio shot from there to Phu Lam.
		Tropospheric scatter radio used radio signals bounced off the troposphere and had just emerged from the R & D laboratory.
		Based on reports of Phu Lamers who visited Vietnam recently, the base is still used for military communications, with the barracks and tropospheric antennas still standing as an ironic reminder of the U.S. Army Signal Corps communicators who called Phu Lam home for more than ten years.
	phulam.com /history.htm (2529 words)

	GLOSSARY T
		TROPOSPHERE - (1) The lower layers of atmosphere, in which the change of temperature with height is relatively large.
		TROPOSPHERIC SCATTER - The propagation of electromagnetic waves by scattering as a result of irregularities or discontinuities in the physical properties of the troposphere.
		TROPOSPHERIC SCATTER PROPAGATION - Propagation of radio waves through the atmosphere involving scattering from inhomogeneities in the
	www.sew-lexicon.com /gloss_t.htm (5902 words)

	COMMUNICATIONS
		Messages were relayed manually at a teletypewriter relay station by taking an incoming message off the receiving equipment in the form of punched tape and inserting the same tape at the appropriate send positions to transmit the message on to its destination.
		These tropospheric scatter trunks would be advantageous since, unlike conventional microwave, which needs a line-of- sight between sets, they would pass over the vast distances of underpopulated, enemy-infested terrain to connect the major operations and population centers in Vietnam north of Saigon.
		Although these large tropospheric terminals, each of which was mounted in three large semitrailers, were designed for transportable operation, their 30-foot antennas could not be used due to the long path distances.
	home.earthlink.net /~bfwillia/commelec.html (1933 words)

	Radio Terminal Set - WikiPershing
		Description: The TRC-80 is a transportable microwave FM radio communication station capable of transmitting and receiving radio signals by use of the tropospheric scatter method of radio propagation.
		Description: The TRC-80A is a transportable microwave FM radio communication station capable of transmitting and receiving radio signals by use of the tropospheric scatter method of radio propagation.
		Description: The TRC-80B is a transportable microwave FM radio communication station capable of transmitting and receiving radio signals by use of the tropospheric scatter method of radio propagation.
	wiki.pershingmissile.org /index.php/Radio_Terminal_Set (412 words)

	Chapter 7 - Communication-Electronics, 1962-1970
		The Integrated Wideband Communications System was a microwave and tropospheric scatter communications web that eventually spanned the entire Republic of Vietnam and Thailand.
		The solution to these problems, however temporary, was to use every piece of medium and heavy tropospheric scatter, microwave, and other mobile and transportable multichannel radio equipment that could be deployed into Vietnam.
		Consequently, the mobile tropospheric scatter and microwave links of the Defense Communications System were rushed into service and abounded throughout the country, not only providing circuitry from the backbone system to locations that would one day be served by the fixed communications being installed, but also sup-
	www.army.mil /Cmh-Pg/books/Vietnam/Comm-El/ch7.htm (3181 words)

	US Army Info Site: MOS 25Q: Multichannel Transmission Systems Operator - Maintainer
		Installs, operates, and performs unit level maintenance on multichannel line-of-site and tropospheric scatter communications systems, antennas and associated equipment.
		Supervises operations and assists team members in the installation and operation of multichannel line-of-site and tropospheric scatter communications systems.
		Supervises and prepares work schedules for subordinate personnel engaged in the installation, operation, and unit level maintenance of multichannel and tropospheric scatter radio systems.
	www.us-army-info.com /pages/mos/signal/31r.html (415 words)

	How Tropospheric Scatter Works (Site not responding. Last check: 2007-11-01)
		Here is a simplified explanation of Tropospheric Scatter, as used on the North Atlantic Radio System.
		The common volume is the area of the troposphere, up to about six miles above earth, where the beams from both sites, which have now spread to cover a much larger area, converge.
		Finally, it is routed to the multiplex to be broken up into individual circuits, again.
	www.westgeorgia.org /nars/abttropo.htm (327 words)

	Notes on microwave scattering
		Rain Scatter and Tropospheric Enhancement on 10 GHz (Summer 2005):
		This means that in the cases of Tropospheric Enhancement and Forward Rain Scatter, the signals are received via at least two reflections.
		scatter on 29.08.2005 (light rain, single front, high headwind)
	www.kolumbus.fi /michael.fletcher/scatter_10_GHz_summer_2005.htm (439 words)

	UTARC VHF (Site not responding. Last check: 2007-11-01)
		N5XU is the only college or university club station in the country to have earned the prestigious VHF/UHF Century Club (VUCC) award from the American Radio Relay League (ARRL.) The club station has been used to work several countries in two continents on 50 MHz.
		We are active on HSCW and SSB meteor scatter on 144 MHz, and we are starting to become active on the microwave bands.
		The club station has been used to make contacts via "Sporadic E", meteor scatter, tropospheric scatter, tropospheric ducting, TEP, and "moonbounce" propagation modes.
	n5xu.ae.utexas.edu /vhf (548 words)

	Tropospheric Scatter System
		Now let us take a look at another system.
		The los system uses towers to relay information.
		The tropo system uses the turbulence in the layer between the troposphere and the stratosphere to
	www.tpub.com /content/neets/14189/css/14189_151.htm (149 words)

	The North Atlantic Radio System (
		Whenever a project of any nature spans a period of more than 30 years, employing hundreds of people on a mission with the potential to affect millions, it develops a life of its own.
		A chain of five tropospheric scatter communications sites, stretching from Iceland to England, the NARS system was designed as part of an extension to the DEW Line and was built for the US Air Force by Western Electric (ATandT) in the early 1960s.
		Operated and maintained for most of its 31 years by ITT Federal Electric Corporation (now ITT Federal Services Corp.) or its subsidiaries, the "NARS System," as it was commonly known, became, in a small way, a subculture.
	nars.westgeorgia.org (516 words)

Try your search on: Qwika (all wikis)