Geostationary satellite .

• geostationary satellite

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Communications satellite History

1 An immediate antecedent of the geostationary satellites was Hughes'

Syncom 2, launched on July 26, 1963. Syncom 2 revolved around the

earth once per day at constant speed, but because it still had north-south motion, special equipment was

needed to track it.


Communications satellite Geostationary orbits

1 The first geostationary satellite was Syncom 3, launched on August 19, 1964, and used

for communication across the Pacific starting with television coverage of the 1964 Summer Olympics. Shortly after

Syncom 3, Intelsat I, aka Early Bird, was launched on April 6, 1965 and placed in

orbit at 28° west longitude. It was the first geostationary satellite for

telecommunications over the Atlantic Ocean.


Communications satellite Geostationary orbits

1 On November 9, 1972, Canada's first geostationary satellite serving the

continent, Anik A1, was launched by Telesat Canada, with the United

States following suit with the launch of Westar 1 by Western Union on

April 13, 1974.


Communications satellite Low-Earth-orbiting satellites

1 Low-Earth-orbiting satellites are less expensive to launch into orbit than geostationary

satellites and, due to proximity to the ground, do not require as high signal strength (Recall that signal strength falls off as the square of the distance from the source, so the effect is dramatic). Thus there is a trade off between

the number of satellites and their cost. In addition, there are important differences in the

onboard and ground equipment needed to support the two types of missions.


Communications satellite Molniya satellites

1 For areas close to the North (and South) Pole, a geostationary satellite

may appear below the horizon


Communications satellite Telephone

1 The fixed Public Switched Telephone Network relays telephone calls from

land line telephones to an earth station, where they are then

transmitted to a geostationary satellite


Satellite - Early conceptions

1 The book described geostationary satellites (first put forward by

Tsiolkovsky) and discussed communication between them and

the ground using radio, but fell short of the idea of using satellites for

mass broadcasting and as telecommunications relays.


Satellite - Early conceptions

1 In a 1945 Wireless World article the English science fiction writer Arthur C. Clarke (1917–2008) described in detail the possible use of

communications satellites for mass communications. Clarke examined the logistics

of satellite launch, possible orbits and other aspects of the creation of a network of world-circling satellites, pointing to the benefits of high-speed global communications. He also

suggested that three geostationary satellites would provide coverage over the entire planet.


Satellite - End of life

1 As of 2002, the FCC requires all geostationary satellites to commit to moving to a graveyard orbit at the end of their operational life prior to

launch


Satellite - Jamming

1 Also, it is trivial to transmit a carrier radio signal to a geostationary

satellite and thus interfere with the legitimate uses of the satellite's

transponder


Satellite Internet access

1 Satellite Internet access is Internet access provided through

communications satellites. Modern satellite Internet service is typically

provided to users through geostationary satellites that can offer

high data speeds, with newer satellites achieving downstream data

speeds up to 15 Mbps


Satellite Internet access - History of satellite Internet

1 Following the invention of the Internet and the World Wide Web, geostationary satellites attracted interest as a potential means of

providing Internet access.


Satellite Internet access - Signal latency

1 The round trip latency of a geostationary satellite

communication's network is almost 20 times that of a terrestrial based

network.


Satellite Internet access - Geostationary unsuitable for low-latency applications

1 Compared to ground-based communication, all geostationary

satellite communications experience high latency due to the signal having to travel 35,786 km (22,236 mi) to a satellite in geostationary orbit and

back to Earth again


Satellite Internet access - Geostationary unsuitable for low-latency applications

1 For geostationary satellites, there is no way to eliminate latency, but the problem can

be somewhat mitigated in Internet communications with TCP acceleration

features that shorten the round trip time (RTT) per packet by splitting the feedback loop between the sender and the receiver.

Such acceleration features are usually present in recent technology developments embedded in new satellite Internet services.


Satellite Internet access - Acceptable latencies, but lower speeds, of lower orbits

1 Unlike geostationary satellites, low and medium Earth orbit satellites do not stay in a fixed position in the sky


Satellite Internet access - System components

1 Latency is still high, although lower than full two-way geostationary

satellite Internet, since only half of the data path is via satellite, the

other half being via the terrestrial channel.


Telecommunication - Satellite



transmitted to a receiving satellite dish via a geostationary satellite in

Earth orbit


Telecommunications in Brazil - Satellite connections

1 List of business and satellites they operate (Brazilian Geostationary Satellites)


History of telecommunication - Satellite



transmitted a receiving satellite dish via a geostationary satellite in Earth

orbit


Telenor - Broadcast

1 Telenor also operates the national terrestrial broadcast network in Norway, through its subsidiary Norkring. It is also part owner of Norges Televisjon and the

content provider RiksTV. Telenor is also the leading provider of satellite broadcasting

services in the Nordic region, utilising three geostationary satellites. Telenor's key objective is to further strengthen

Broadcast's position in the Nordic region.


Voice over IP - Quality of service

1 Fixed delays cannot be controlled as they are caused by the physical

distance the packets travel. They are especially problematic when satellite circuits are involved because of the

long distance to a geostationary satellite and back; delays of 400–600

ms are typical.


Space elevator - 20th century

1 Artsutanov suggested using a geostationary satellite as the base from which to deploy the structure

downward


Satellite Internet access - Acceptable latencies, but lower speeds, of lower orbits

1 Unlike geostationary satellites, low and medium Earth orbit satellites do not stay in a fixed position in the sky


Telecommunications in the Cook Islands - Internet

1 It has a latency (engineering)|latency of about 100 milliseconds because it is much closer to Earth than standard

geostationary satellites, whose latencies can be over 600

milliseconds


Telecommunications in North America - Satellite



transmitted to a receiving satellite dish via a geostationary satellite in

Earth orbit


Satellite phone - Geosynchronous satellites

1 Geostationary satellites have a limitation of use in latitude, generally

70 degrees north of the equator to 70 degrees south of the equator.

This is a result of look angles being so low on the horizon increasing the

chances of terrestrial and other interference from sources in the

same frequency bands.


Satellite phone - Geosynchronous satellites

1 Another disadvantage of geostationary satellite systems is that in many areas—even where a

large amount of open sky is present—the line-of-sight between the phone

and the satellite is broken by obstacles such as steep hills and

forest


Arthur C. Clarke

1 Clarke for Geostationary Satellite Communications][http://web.archive.org/web/20110725175706/http://ww

w.clarkefoundation.org/archives/1996.php The Arthur C


Arthur C. Clarke - Postwar

1 Although he was not the originator of the concept of geostationary

satellites, one of his most important contributions may be his idea that

they would be ideal telecommunications relays


Arthur C. Clarke - Undersea diving

1 This, he believed, would make rocket based access to space obsolete and, more than geostationary satellites, would ultimately be his scientific

legacy.Personal e-mail from Sir Arthur Clarke to Jerry Stone, Director of the

Sir Arthur Clarke Awards, 1 November 2006


Arthur C. Clarke - The Geostationary communications satellite

1 Clarke contributed to the popularity of the idea that geostationary

satellites would be ideal telecommunications relays


Arthur C. Clarke - The Geostationary communications satellite

1 For example, the concept of geostationary satellites was described in Hermann Oberth's 1923 book Die Rakete zu

den Planetenräumen (The Rocket into Interplanetary Space) and then the idea of radio communication with those satellites in Herman Potočnik's (written under the

pseudonym Hermann Noordung) 1928 book Das Problem der Befahrung des Weltraums— der Raketen-Motor

([http://www.hq.nasa.gov/office/pao/History/SP-4026/contents.html The Problem of Space Travel—The Rocket

Motor]), sections: Providing for Long Distance Communications and Safety and (possibly referring to the

idea of relaying messages via satellite, but not that 3 would be optimal) Observing and Researching the Earth's

Surface published in Berlin


Electrodeless plasma thruster - Applications

1 Propulsion systems based on electrodeless plasma thrusters seem

ideally suited for orbit raising for large geostationary satellites, and

would also be able to perform orbital stationkeeping, hence enabling

important propellant mass savings. The ability of this technology to provide large thrust density also

allows faster missions to the outer planets.


Ion thruster - Operational missions

1 Two geostationary satellites (ESA's Artemis (satellite)|Artemis in 2001-

2003 and the US military's AEHF-1 in 2010-2012) have used the ion

thruster for orbit raising after the failure of the chemical-propellant

engine


Geographic coordinate system - Geostationary coordinates

1 Geostationary satellites (e.g., television satellites) are over the

equator at a specific point on Earth, so their position related to Earth is

expressed in longitude degrees only. Their latitude is always zero, that is,

over the equator.


Satellite images - Moving images

1 In 2005 the Australian company Astrovision (ASX: HZG) announced plans to launch the first commercial geostationary orbit|geostationary

satellite in the Asia-Pacific. It is intended to provide true color, real-time live satellite

feeds, with down to 250 metres resolution over the entire Asia-Pacific region, from India to

Hawaii and Japan to Australia. They were going to provide this content to users of 3G mobile phones, over Pay TV as a weather channel,

and to corporate and government users.


Last mile - Satellite communications

1 For information delivery to end users, satellite systems, by nature, have

relatively long path lengths, even for low earth-orbiting satellites. They are

also very expensive to deploy and therefore each satellite must serve many users. Additionally, the very

long paths of geostationary satellites cause information latency that

makes many real-time applications unfeasible.


Telematics - Trailer tracking

1 Trailer tracking is the technology of tracking the movements and position of an articulated vehicle's trailer unit,

through the use of a location unit fitted to the trailer and a method of

returning the position data via mobile communication network or

geostationary satellite communications, for use through either PC- or web-based software.


NOAA - National Environmental Satellite, Data, and Information Service (NESDIS)

1 The service operates and manages many geosynchronous satellites and

polar orbiting satellites. In 1960 TIROS-1, NOAA's first owned and

operated geostationary satellite was launched. In 1983 NOAA assumed

operational responsibility for Landsat program|LANDSAT satellite system. In 1984 the Tropical Ocean-Global

Atmosphere program (TOGA) program began.


Wind - Measurement

1 Geostationary satellite imagery can be used to estimate the winds

throughout the atmosphere based upon how far clouds move from one

image to the next


Satellite TV - History

1 ATS-6, the world's first experimental educational and Direct Broadcast

Satellite, was launched in 1974. The first Soviet geostationary satellite to

carry Direct-To-Home television, called Ekran, was launched in 1976.


Satellite TV - Technology

1 Last but not least, there will be a sun outage when the sun lines up directly behind the

geostationary satellite the reception antenna is pointing to. This will happen twice a year

at around midday for a two-week period and affects both the C-band and the Ku-band. The line-up swamps out all reception for a

few minutes due to the sun emitting microwaves on the same frequencies used

by the satellite's transponders. This happens in the spring and in the fall.


Satellite TV - Technology

1 The disk will then be capable of receiving any geostationary satellite that is visible at the specific location,

i.e


Beidou navigation system - Description

1 BeiDou-2 (formerly known as COMPASS) is not an extension to the

older BeiDou-1, but rather supersedes it outright. The new

system will be a constellation of 35 satellites, which include 5

geostationary orbit satellites for backward compatibility with BeiDou-

1, and 30 non-geostationary satellites (27 in medium earth orbit and 3 in inclined geosynchronous

orbit), that will offer complete coverage of the globe.


Geosynchronous orbit - History

1 Geostationary satellites also carry international telephone traffic but

they are being replaced by fiber optic cables in heavily populated areas

and along the coasts of less developed regions, because of the greater bandwidth available and

lower latency, due to the inherent disconcerting delay in

communicating via a satellite in such a high orbit


GPS-aided geo-augmented navigation - Developments

1 The first GAGAN transmitter was integrated into the GSAT-4

geostationary orbit|geostationary satellite, and had a goal of being

operational in 2008.[http://www.india-

defence.com/reports/2239 ISRO, Raytheon complete tests for GAGAN Satellite Navigational System.] India

Defense Websitehttps://store.theartofservice.com/the-geostationary-satellite-toolkit.html

GPS-aided geo-augmented navigation - Satellites

1 'GSAT-8' is an Indian geostationary satellites, which was successfully

launched using Ariane 5 on 21 May 2011 and is positioned in

geosynchronous orbit at 55 degrees E longitude.


Wide Area Augmentation System - Ground segment

1 The reference stations also monitor signals from WAAS geostationary

satellites, providing integrity information regarding them as well


Wide Area Augmentation System - Space segment

1 As with the previous satellites, these are leased services under the FAA's Geostationary

Satellite Communications Control Segment contract with Lockheed Martin for WAAS

geostationary satellite leased services, who is contracted to provide up to three satellites

through the year 2016.Federal Aviation Administration (FAA) Announcement

[http://gps.faa.gov/Library/Data/waas/March_2005.doc March 2005] A third satellite was

later added to the system


Blok D

1 Blok DM also flies as the third stage for Zenit-3SL rocket, which is used by

the Sea Launch project to launch geostationary satellites. In 2002 the failure of a Blok DM3—used in the attempted launch of Astra 1K—caused considerable concern.


Quasi-Zenith Satellite System

1 Its positioning service could also collaborate with the geostationary

satellites in Japan's Multi-Functional Transport Satellite (MTSAT), currently under development, which itself is a

Satellite Based Augmentation System similar to the U.S


Bell TV - Satellites

1 Bell TV broadcasts from four geostationary satellites: Nimiq 1, 2, 3 and 4iR. Nimiq 4iR is temporary and is being replaced by Nimiq 4. All follow an equatorial path, giving coverage

to most of Canada. Nimiq is an Inuktitut language|Inuktitut word for that which unifies

and was chosen from a nationwide naming contest in 1998. The four satellites are owned and operated by Telesat Canada. Bell's uplink

site is located in North York which is in the Toronto area.


Geostationary Earth Orbit - Orbital stability

1 A geostationary orbit can only be achieved at an altitude very close to , and directly

above the Equator. This equates to an orbital velocity of or a period of 1,436 minutes,

which equates to almost exactly one sidereal day or 23.934461223 hours. This ensures that the satellite is locked to the Earth's rotational period and has a stationary

Footprint (satellite)|footprint on the ground. All geostationary satellites have to be

located on this ring.


Geostationary Earth Orbit - Communications

1 At latitudes above about 81°, geostationary satellites are below the

horizon and cannot be seen at all.[http://www.ngs.noaa.gov/CORS/Artic

les/SolerEisemannJSE.pdf p


European Geostationary Navigation Overlay Service

1 According to specifications, horizontal position accuracy should

be better than seven metres. In practice, the horizontal position

accuracy is at the metre level. The EGNOS system consists of four geostationary satellites and a network of ground stations.


European Geostationary Navigation Overlay Service - Satellites

1 The use of EGNOS on the ground, especially in urban areas, is limited

due to relatively low elevation of geostationary satellites: about 30°

above horizon in central Europe and much less in the North of Europe


European Geostationary Navigation Overlay Service - Ground stations

1 * 6 NLES ('N'avigation 'L'and 'E'arth 'S'tations): accuracy and reliability data sending to three geostationary satellite transponders to allow end-

user devices to receive them.


Compass bearing - Usage

1 The bearing for geostationary

satellites is constant


Ocean observations - Future developments

1 * Satellite observations with higher resolution and accuracy and more spectral bands from geostationary

satellites


Geostationary Operational Environmental Satellite

1 The 'Geostationary Satellite' system ('GOES'), operated by the United

States NESDIS|National Environmental Satellite, Data, and

Information Service (NESDIS), supports weather forecasting, severe

storm tracking, and meteorology research


Geostationary Operational Environmental Satellite - Satellites

1 Geostationary satellites cannot ordinarily be seen at all from the poles, but they require station-

keeping fuel to keep them stationary over the equator


SES S.A.

1 SES is the world’s second-largest telecommunications satellite

operator by revenue and operates a fleet of 55 geostationary satellites able to reach 99% of the World’s

population.SES Global Connections via Satellite


Hughes Research Laboratories - Notable accomplishments

1 * HRL began research on ion propulsion in 1961. This research led to the Hughes developed xenon ion propulsion system (XIPSTM). XIPS was used as the primary

propulsion system on NASA's Deep Space 1 (launched in 1998). It is a standard option

for primary stationkeeping on the Hughes/Boeing 601HP (first use: Intelsat 5|PAS-5, 1997) and the 702 (first use: Galaxy-

XI, 1999) geostationary satellite families.


Aerovironment - Subsidiaries

1 A single SkyTower platform can provide over 1,000 times the fixed

broadband local access capacity of a geostationary satellite using the

same frequency band, on a bytes per second per square mile basis.

[http://www.space.com/missionlaunches/skytower_020724.html David, Leonard, Stratospheric Platform

Serves As Satellite], Space.com, July 24, 2002


Electric beacon - Distress radiobeacons

1 When activated, these beacons send out a distress signal that, when detected by geostationary|non-geostationary satellites, can be

located by triangulation


Solaris Mobile

1 'Solaris Mobile' is a joint venture company between SES S.A.|SES and Eutelsat Communications to develop

and commercialize the first geostationary satellite systems in

Europe for broadcasting video, radio and data to in-vehicle receivers and to mobile devices, such as mobile

phones, portable media players and PDAs.


Solaris Mobile

1 The services to be developed include video, radio, multimedia data, interactive services, and voice communications. The primary aim is the delivery of mobile television any time,

anywhere, and SES and Eutelsat – both successful European satellite operators,

providing TV and other services from geostationary satellites to millions of cable and direct-to-home viewers – have so far

invested €130m in the venture.


Sirius Satellite Radio - SiriusXM for Business

1 To eliminate this potential problem, Sirius launched a new geostationary satellite, FM-5, to improve service to non-mobile customers such as those

of SiriusXM for Business


S-DMB

1 'S-DMB' ('Satellite-DMB') is a hybrid version of the Digital Multimedia Broadcasting. The S-DMB uses the S band (2170-2200MHz) of IMT-2000. and delivers around 18 channels

at 128 kbit/s in 15MHz. It incorporates a high power geostationary satellite, the MBSat 1. For outdoor and light indoor

coverage is integrated with a terrestrial repeater (low power gap-filler) network for

indoor coverage in urban areas.


Darmstadt, Germany - Technology

1 EUMETSAT, the European Organisation for the Exploitation of Meteorological Satellites, operates

the principal European meteorological satellites from its

headquarters, including the first and second generations of Meteosat geostationary satellites, and the

polar-orbiting Metop series.


Lunar space elevator - History

1 Then in 1966, John Isaacs, a leader of a group of American Oceanographers at Scripps

Institution of Oceanography|Scripps Institute, published an article in Science (magazine)|

Science about the concept of using thin wires hanging from a geostationary satellite. In that

concept, the wires were to be thin (thin wires/tethers are now understood to be more susceptible to micrometeoroid damage). Like

Artsutanov, Isaacs’ article also wasn’t well known to the aerospace community.


Indian Space Research Organization - The INSAT series

1 INSAT (Indian National Satellite System) is a series of multipurpose geostationary satellites launched by

ISRO to satisfy the telecommunications, broadcasting, meteorology and search-and-rescue

needs of India


Indian Space Research Organization - Other satellites

1 ISRO has also launched a set of experimental geostationary satellites known as the GSAT series. Kalpana-1, ISRO's first dedicated meteorological satellite, was launched by the Polar

Satellite Launch Vehicle on 12 September 2002. The satellite was

originally known as MetSat-1. In February 2003 it was renamed to

Kalpana-1 by the Indian Prime Minister Atal Bihari Vajpayee in

memory of Kalpana Chawla – a NASA astronaut of Indian origin who

perished in Space Shuttle Columbia.


Indian Space Research Organization - GAGAN

1 The first GAGAN navigation payload has been fabricated and it was proposed to be flown on

GSAT-4 during Apr 2010. However, GSAT-4 was not placed in orbit as GSLV-D3 could not

complete the mission. Two more GAGAN payloads will be subsequently flown, one

each on two geostationary satellites, GSAT-8 and GSAT-10. On 12 May 2012, ISRO

announced the successful testing of its indigenous cryogenic engine for 200 seconds

for its forthcoming GSLV-D5 flight.


LightSquared - Origins

1 The company has operated in the North American market with two geostationary

satellites since 1995


Artificial satellite - Early conceptions

1 The book described geostationary satellites (first put forward by

Tsiolkovsky) and discussed communication between them and

the ground using radio, but fell short of the idea of using satellites for

mass broadcasting and as telecommunications relays.


Artificial satellite - Early conceptions

1 In a 1945 Wireless World article, the English science fiction writer Arthur C. Clarke (1917–2008) described in detail the possible use of

communications satellites for mass communications. Clarke examined the logistics

of satellite launch, possible orbits and other aspects of the creation of a network of world-circling satellites, pointing to the benefits of high-speed global communications. He also

suggested that three geostationary satellites would provide coverage over the entire planet.


Artificial satellite - End of life

1 As of 2002, the FCC requires all geostationary satellites to commit to moving to a graveyard orbit at the end of their operational life prior to

launch


Malaysian National Space Agency - MEASAT

1 As of 2006, the MEASAT satellite network consisted of three

Geostationary orbit|geostationary satellites designed and built by

Boeing Satellite Development Center|Boeing Satellite Systems. MEASAT-1

and MEASAT-2 were launched in 1996 and MEASAT-3 in 2006.


SpaceX

1 Besides NASA contracts, SpaceX has signed contracts with private sector

companies, non-American government agencies and the

American military for its launch services, filling a growing launch

manifest. It has already launched, for a paying customer, a low earth

orbiting satellite with its Falcon 1 booster in 2009. And on 3 December 2013, the company launched its first commercial geostationary satellite

from a Falcon 9.


Space debris - Debris at higher altitudes

1 There has been estimated to be one close (within 50 meters) approach

per year.[http://www.weblab.dlr.de/rbrt/p

df/ISSFD_89085.pdf Colocation Strategy and Collision Avoidance for

the Geostationary Satellites at 19 Degrees West.] CNES Symposium on

Space Dynamics, 6–10 November 1989.


Space debris - Debris at higher altitudes

1 Hechler, [http://adsabs.harvard.edu//abs/1981

rome.iafcR....V The Collision Probability of Geostationary Satellites] 32nd International

Astronautical Congress, 1981, p


Space debris - Self-removal

1 It is an ITU requirement that geostationary satellites be able to remove themselves to a graveyard orbit at the end of their lives. It has

been demonstrated that the selected orbital areas do not sufficiently protect GEO lanes from debris,

although a response has not yet been formulated.


Optus - Network Backbone

1 ** Fleet of geostationary

satellites (See Optus fleet of satellites)


Equinox - Equinoxes of other planets

1 For all geostationary orbit|geostationary satellites, there are a few days around the equinox when

the sun goes directly behind the satellite relative to Earth (i.e


Astronomical interferometer - History of astronomical interferometers

1 The Navy Optical Interferometer took the first step in this direction in 1996, achieving seminal 3-way

synthesis of an image of Mizar (star)|Mizar then;http://adsabs.harvard.edu/cgi-bin/nph-

bib_query?bibcode=1997AJ....114.1221Bdb_key=ASThigh=35eb76bdc314153 then a first-ever six-way synthesis of

Eta Virginis in 2002;http://adsabs.harvard.edu/abs/2003AJ....125.2630H and most recently closure phase as a step to the

first synthesized images of geostationary satellites.http://adsabs.harvard.edu/abs/2011ApOpt..

50.2692H


List of English inventions and discoveries - Communications

1 *The originator of the concept of geostationary satellites for the use of telecommunications relays – Arthur C

Clarke


Analemma - Analemmas of geosynchronous satellites

1 A geostationary satellite therefore ideally remains stationary relative to the Earth's surface, staying over a

single point on the equator


Analemma - Analemmas of geosynchronous satellites

1 The paraboloidal dishes that are used for radio communication with geosynchronous satellites often have to move so as to follow

the satellite's daily movement around its analemma. The mechanisms that drive them

must therefore be programmed with the parameters of the analemma. Exceptions are

dishes that are used with (approximately) geostationary satellites, since these satellites appear to move so little that a fixed dish can

function adequately at all times.


BGAN

1 The network is provided by Inmarsat and uses three geostationary

satellites called I-4 satellite|I-4 to provide almost global coverage.


BGAN - Signal acquisition

1 The terminal then needs a line-of-sight to the geostationary satellite so

a user would normally be outside, and have a general idea of what

direction the satellite would be (with a compass if necessary)


Propellant Depot - Space tug alternatives to direct refueling

1 ViviSat believes their approach is more simple and can operate at

lower cost than the MDA propellant transfer approach, while having the

technical ability to dock with and service a greater number (90

percent) of the approximately 450 geostationary orbit|geostationary

satellites in orbit.


Sun outage

1 A 'sun outage', 'sun transit' or 'sun fade' is an interruption in or

distortion of Geosynchronous satellite|geostationary satellite

signals caused by interference from solar radiation. The effect is due to

the sun's radiation overwhelming the satellite signal.


Chandra X-ray Observatory - Technical description

1 Chandra's highly ellipse|elliptical orbit allows it to observe

continuously for up to 55 hours of its 65 hour orbital period. At its furthest orbital point from earth, Chandra is

one of the most distant earth-orbiting satellites. This orbit takes it beyond

the geostationary satellites and beyond the outer Van Allen belt.


Commsat - History

1 An immediate antecedent of the geostationary satellites was Hughes Aircraft Company|Hughes' Syncom|

Syncom 2, launched on July 26, 1963. Syncom 2 revolved around the

earth once per day at constant speed, but because it still had north-south motion, special equipment was

needed to track it.


Commsat - Molniya satellites

1 For areas close to the North (and South) Pole, a geostationary satellite

may appear below the horizon


Beal Aerospace - Launch Vehicles

1 The original BA-1 launch vehicle design was intended to service the

LEO (Low Earth Orbit) satellite constellation launch market, but was

replaced by the much larger BA-2 design when it was decided to

concentrate on the more stable Geostationary satellite launch market

as the LEO constellations became financially unsound


SES S.A.

1 Accessed August 26, 2014 geostationary satellites able to reach

99% of the World’s population.SES Global Connections via Satellite


MVDDS dispute - FCC licensing controversy

1 Northpoint filed its application in a filing window for non-geostationary satellite systems, and claimed that its terrestrial system was entitled to

the same rights given to other applications filed in that window,

which employed the same frequency range


Global Maritime Distress Safety System - Emergency position-indicating radio beacon (EPIRB)

1 The original COSPAS/SARSAT system used polar orbiting satellites but in recent years the system has been

expanded to also include 4 geostationary satellites


Global Maritime Distress Safety System - Sea Area A3

1 An area, excluding sea areas A1 and A2, within the coverage of an

Inmarsat geostationary satellite. This area lies between about latitude 76

Degrees North and South, but excludes A1 and/or A2 designated areas. Inmarsat guarantees their

system will work between 70 South and 70 North though it will often

work to 76 degrees South or North.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

Satcom (satellite)

1 Satcom was one of the early geostationary satellites; the first were the Syncom series, in

1964


Geosynchronous satellite

1 A special case of geosynchronous satellite is the 'geostationary

satellite', which has a geostationary orbit – a circular geosynchronous orbit directly above the Earth's

equator


Geosynchronous satellite

1 Geostationary satellites have the special property of remaining

permanently fixed in exactly the same position in the sky, meaning that ground-based antennas do not need to track them but can remain

fixed in one direction


Geosynchronous satellite - Application

1 Geostationary satellites appear to be fixed over one spot above the

equator. Receiving and transmitting. Antenna (radio)|antennas on the earth do not need to track such a satellite. These antennas can be fixed in place and are much less

expensive than tracking antennas. These satellites have revolutionized

global Telecommunication|communications, television broadcasting and weather

forecasting, and have a number of important military|defense and

intelligence applications.



1 Slow start is very slow over a path

using a geostationary

satellite.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html


1 Another disadvantage of geostationary satellites is the

incomplete geographical coverage, since ground stations at higher than

roughly 60 degrees latitude have difficulty reliably receiving signals at

low elevations


Satellite broadcasting - Technology

1 On occasion, sun outage will occur when the sun lines up directly behind the

geostationary satellite the reception antenna is pointing to. This will happen twice a year at around midday for a two-week period in the spring and in the fall, and affects both the C-band and the Ku-band. The line-up

swamps out all reception for a few minutes due to the sun emitting microwaves on the

same frequencies used by the satellite's transponders.


Satellite broadcasting - Early milestones

1 In 1945 British science fiction writer Arthur C. Clarke proposed a world-

wide communications system which would function by means of three satellites equally spaced apart in

earth orbit. This was published in the October 1945 issue of the Wireless World magazine and won him the

Franklin Institute's Stuart Ballantine Medal in

1963.[http://lakdiva.org/clarke/1945ww The 1945 Proposal by Arthur C. Clarke for Geostationary Satellite

Communications]


Satellite broadcasting - Early milestones

1 The first in a series of Soviet geostationary satellites to carry

Direct-To-Home television, Ekran 1, was launched on 26 October 1976. It

used a 714MHz UHF downlink frequency so that the transmissions could be received with existing UHF

television broadcasting|UHF television technology rather than

microwave technology.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

List of broadcast satellites

1 The major consideration for spacing of geostationary satellites is the

beamwidth at-orbit of uplink transmitters, which is primarily a

factor of the size and stability of the uplink dish, as well as what frequencies the satellite's

transponders receive; satellites with discontiguous frequency allocations

can be much closer together.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

Weather satellite - History

1 Geostationary satellites followed, beginning with the ATS and SMS

series in the late1960s and early1970s, then continuing with the GOES series from the 1970s onward


Weather satellite - Geostationary

1 China operated the Feng-Yun(風雲 ) geostationary satellites FY-2D at

86.5°E and FY-2E at 123.5°E, which are no longer in use.


Space warfare - Practical considerations

1 Second, space travel involves tremendous speeds by terrestrial standards—a geostationary orbit|geostationary satellite moves at a

speed of 3.07km/s whereas objects in low earth orbit can move at up to

8km/s


Inmarsat - Global Voice Services

1 Competing systems such as from Skybitz only operate on the MSAT geostationary satellite over North

America.


Distress radiobeacon

1 The signals are monitored worldwide and the location of the distress is detected by non-geostationary

satellites, and can be located by some combination of GPS

trilateration and doppler effect|doppler

triangulation.[http://www.cospas-sarsat.org/en/operatons/operations-

concept/what-happens-when-i-activate-my-beacon What happens

when I activate my beacon?]


Distress radiobeacon - Location by Doppler (without GPS)

1 Local unit terminals (LUTs) detecting non-geostationary satellites interpret the Doppler effect|Doppler frequency shift heard by LEOSAR and MEOSAR satellites as they pass over a beacon

transmitting at a fixed frequency


Distress radiobeacon - Satellites

1 Some geosynchronous satellites have beacon receivers. Since the end of

2003 there are four such geostationary satellites (GEOSAR) that cover more than 80% of the surface of the earth. As with all

geosynchronous satellites, they are located above the equator. The

GEOSAR satellites do not cover the polar caps.


Distress radiobeacon - EPIRB sub-classification

1 * Inmarsat-E – This service ended 1 December 2006; all former users have switched to Category I or II

406MHz EPIRBs. These beacons were float-free, automatically activated

EPIRBs operated on 1646MHz. They were detectable by Inmarsat

geostationary satellites, and were recognized by GMDSS. See

Inmarsat-E.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

Distress radiobeacon - Obsolete EPIRBs

1 *Inmarsat E – entered service in 1997. The unit is an automatic activation unit operating on 1646MHz and detectable by the Inmarsat geostationary satellite system. This class of EPIRB was approved by the Global Maritime Distress Safety System (GMDSS), but not by

the United States. In September 2004, Inmarsat announced that it was terminating its Inmarsat E EPIRB service as of December 2006 due to a lack of interest in the maritime

community.


Tooway

1 'Tooway' Satellite Internet access|satellite broadband Internet service available across Europe. The service

was launched in 2007 via two Eutelsat Geostationary orbit|

geostationary satellites, Hot Bird 6 and Eurobird 3, respectively at the 13° and 33° East orbital positions.


Tooway - Services

1 Tooway services operate over and via Eutelsat's geostationary

satellites. This enabled bit rates of 3.6 Mbit/s downstream and 384 kbit/s upstream in 2009. Service differentiation is done on volume consumption per month through a

Fair Access Policy. When consumption is above volume thresholds, the service remains available but at

lower speeds.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

Direct-broadcast satellite television - Technology

1 Sun outage occurs when the sun lines up directly between the geostationary satellite the earth station. This happens twice every year around midday for a two-week period in the spring and fall around the equinoxes,

and affects both the C-band and the Ku-band. The line-up swamps out all reception for a few minutes due to the sun emitting microwaves on the same frequencies used

by the satellite's transponders.


TCP tuning - Bandwidth-delay product (BDP)

1 To give a practical example, two nodes communicating over a

geostationary satellite link with a round trip delay of 0.5 seconds and a bandwidth of 10 Gbit/s can have up to 0.5times;1010 bits, i.e., 5 Gbit =

625 megabyte|MB of unacknowledged data in flight


Weightlessness - A common misconception

1 A geostationary satellite is of special interest in this context. Unlike other objects in the sky which rise and set,

an object in a geostationary orbit appears motionless in the sky,

apparently defying gravity. In fact, it is in a circular equatorial orbit with a

period of one day.


Central dense overcast - Use as a tropical cyclone strength indicator

1 Tropical cyclones with maximum sustained winds between and can have their center of

circulations obscured by cloudiness within visible and infrared satellite imagery, which

makes diagnosis of their intensity a challenge. Winds within tropical cyclones can also be estimated by tracking features within

the CDO using rapid scan Weather satellite#Geostationary|geostationary

satellite imagery, whose pictures are taken minutes apart rather than every half hour.


Satmex - Timeline

1 May: Telecomm hires Hughes for the construction of the Solidaridad

Satellites. It consists of two HS-601 geostationary satellites with tri-axial stabilization, which were designed to provide C-band services in México, the southern United States and the rest of Latin America, with Ku-band services in Mexico and the United

States.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

Satmex - Timeline

1 The Communications and Transports Secretary (SCT) hires Hughes to build the Mexican satellite system Morelos (two HS-376 geostationary satellites,

stabilized by rotation).


Svalbard Satellite Station - History

1 Construction of the road up to Platåberget started in 1996 and a relay station was built to send the data to Isfjord Radio before being sent onwards to a geostationary

satellite.Wormdal (2011): 40 The first installation was an parabolic

antenna with S and X band capability.


Svalbard Satellite Station - Facilities

1 Their location is based on the need to have as long a line of sight time

between the antenna and satellite; a line of sight to a calibration station

on Hiorthhamnfjellet and, for communication antennas, a line of

sight southwards to see geostationary satellites and a line-of-

sight to Isfjord Radio.


Hurricane Ava (1973) - Impact and records

1 However, the meteorological record for the eastern north Pacific is

unreliable because geostationary satellite observation did not begin

until 1966


STS-38 - Classified payload

1 Rumors that now appear to have been substantiated by the identification of an unknown geostationary satellite by amateur

observers [http://satobs.org/seesat_ref/STS_38/Unknown_GEO_Object_2000

-653A_-_90007_Identified_as_Prowler.pdf Ted Molczan, satobs.org: Unknown GEO Object 2000-653A / 90007 Identified

as Prowler][http://satobs.org/seesat_ref/STS_38/Evaluation_of_the_O

pportunity_to_Launch_Prowler_on_STS_38.pdf Ted Molczan, satobs.org: Evaluation of the opportunity to launch Prowler on

STS-38] insist that a second secret payload was deployed known as Prowler, reportedly a stealth satellite intended to covertly

inspect other nation's geostationary satellites.[http://www.msnbc.msn.com/id/6687654/ns/us_news-

security/t/what-americas-top-secret-spy-program/ Robert Windrem, NBC News: What is America's top-secret spy program?]


Synchronous orbit - Examples

1 Much more commonly, synchronous orbits are employed by artificial

satellites used for communication, such as geostationary satellites.


Graveyard orbit

1 A graveyard orbit is used when the change in velocity required to

perform a de-orbit Orbital maneuver|maneuver is too high. De-orbiting a

geostationary satellite requires a delta-v of about , whereas re-orbiting it to a graveyard orbit only requires

about .[http://www.patentgenius.com/paten

t/5651515.html Method for re-orbiting a dual-mode propulsion

geostationary spacecraft - Patent # 5651515 - PatentGenius]


Graveyard orbit

1 In order to obtain a license to provide telecommunications services in the

United States, the Federal Communications Commission (FCC) requires all geostationary satellites launched after March 18, 2002, to commit to moving to a graveyard

orbit at the end of their operational life. U.S. government regulations

require a boost, \Delta, of ~300 km.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

2012 Atlantic hurricane season - Tropical Storm Florence

1 Due to a further organized appearance on microwave and

geostationary satellite imagery, it is estimated Tropical Depression Six formed at 1800UTC on August3,

while located about 130miles (210km) south-southwest of the

southernmost islands of Cape Verde


Nimiq

1 The 'Nimiq' satellites are a fleet of Geostationary satellite|geostationary

telecommunications satellites owned by the Telesat and used by satellite television

providers including Bell TV and EchoStar (Dish Network). 'Nimiq' is an Inuktitut

language|Inuit word used for an object or a force which binds things together. A contest

in 1998 was held to choose the name of these satellites. The contest drew over

36,000 entries.https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

Astra 1KR

1 'Astra 1KR' is one of the Astra (satellites)|Astra geostationary

satellites owned by SES S.A.|SES. It was launched in April 2006 as a replacement for Astra 1K, which failed to reach orbit on launch in

2002. The launch of Astra 1KR was the first attempted by SES since the

Astra 1K failure.


Hellas Sat

1 'Hellas-Sat Consortium Limited' (Hellas-Sat) is the owner and a

wholesaler of capacity and services of the Greek/Cypriot Hellas-Sat-2

satellite, an Astrium Eurostar E2000+, which was launched

successfully on 13 May, 2003 to the 39th meridian east|39° E orbital

position in the Geostationary orbit|Geostationary Satellite Orbit.


Row 44 - The System

1 Row 44's fuselage-top-mounted Ku-band antennas communicate with

geostationary satellites, allowing Row 44 to offer uninterrupted in-flight Wi-Fi service over water and on airlines'

routes virtually anywhere in the world.


OnAir - Inmarsat SwiftBroadband (L band)

1 A satellite data unit (SDU) manufactured by Thales Group|Thales and branded TopConnect establishes a Backhaul (telecommunications)|

backhaul link to the ground through Inmarsat's SwiftBroadband Geostationary orbit|geostationary satellite constellation operating in the L band around 1500MHz

which allows the use of electronically steerable antennas mounted atop the aircraft fuselage and encased within a fiberglass, RF-

transparent radome


India–Pakistan relations - Technology and education

1 In 2008, India's ISRO scored a great international success by launching its moon probe, Chandrayaan-1 in 2008, and continues to advance its space

program and enhancement of science and technology in India.See:

Chandrayaan-2 With technical assistance from Peoples Republic of China|China, Pakistan launched its first geostationary satellite, Paksat-

1R in 2011.See Paksat-1Rhttps://store.theartofservice.com/the-geostationary-satellite-toolkit.html

For More Information, Visit:

• https://store.theartofservice.com/the-geostationary-satellite-toolkit.html

The Art of Servicehttps://store.theartofservice.com






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