Distinguish among leo, meo, heo & gis systems . what type of satellites kennedy space centre is planning to launch in near future

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Wireless and mobile communication

Distinguish among LEO, MEO, HEO & GIS Systems . What type of satellites Kennedy Space Centre is planning to launch in near future

Submitted to: Sir Madad Ali Shah

By: 4/23/2014

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ContentsSatellite introduction………………………………………………………...3

Types of Satellites

LEO…………………………….…………………………………………….4

MEO……………………………………………………….…………………6

HEO…………………………..………………………….………………….8

Major differences between LEO, MEO & HEO satellite systems……..10

GIS……………………………………………………….……..……………11

Future Launches At Kennedy Space Center…………………..14

Future of Wireless Telephony in Pakistan……………………………..16

Telecom Jobs for Electrical Graduates in Pakistan and Abroad……….18

References……………………………………………….………………….19

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Satellite is any object that moves in a curved path around a planet. The moon is Earth's

original, natural satellite, and there are many man-made (artificial) satellites, usually closer to Earth. The path a satellite follows is an orbit, which sometimes takes the shape of a circle.

To understand why satellites move this way, we must revisit our friend Newton. Newton proposed that a force -- gravity -- exists between any two objects in the universe. If it weren't for this force, a satellite in motion near a planet would continue in motion at the same speed and in the same direction -- a straight line. This straight-line inertial path of a satellite, however, is balanced by a strong gravitational attraction directed toward the center of the planet.

Sometimes, a satellite's orbit looks like an ellipse, a squashed circle that moves around two points known as foci. The same basic laws of motion apply, except that the planet is located at one of the foci. As a result, the net force applied to the satellite isn't uniform all the way around the orbit, and the speed of the satellite changes constantly.

o It moves fastest when it's closest to the planet -- a point known as perigee

o It moves slowest when it's farthest from the planet -- a point known as apogee.

Satellites come in all shapes and sizes and play a variety of roles.Just as different seats in a theater provide different perspectives on a performance, different Earth orbits give satellites varying perspectives, each valuable for different reasons. Some seem to hover over a single spot, providing a constant view of one face of the Earth, while others circle the planet, zipping over many different places in a day. Flying hundreds of kilometers above the Earth, the International Space Station and other orbiting satellites provide a unique perspective on our planet.

Earth and the moon are examples of natural satellites. Thousands of artificial, or man-made, satellites orbit Earth. Some take pictures of the planet that help meteorologists predict weather and track hurricanes. Some take pictures of other planets, the sun, black holes, dark matter or faraway galaxies. These pictures help scientists better understand the solar system and universe.

Still other satellites are used mainly for communications, such as beaming TV signals and phone calls around the world. A group of more than 20 satellites make up the Global Positioning System, or GPS. If you have a GPS receiver, these satellites can help figure out your exact location

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There are essentially three types of Earth orbits: High Earth Orbit (HEO), Medium Earth Orbit (MEO), and Low Earth Orbit (LEO).

We have many satellites in these three orbits for different purposes, some are given as:

LEO Satellite Systems: Comparison of GPS, GLONASS, Galileo and Compass

(medium earth orbit) satellite navigation system orbits with the International Space Station, Hubble Space Telescope and Iridium constellation orbits, Geostationary Earth Orbit, and the nominal size of the Earth. The Moon's orbit is around 9 times larger (in radius and length) than geostationary orbit.

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A low Earth orbit (LEO) is an orbit around Earth with an altitude between 160 kilometers (99 mi), with an orbital period of about 88 minutes, and 2,000 kilometers (1,200 mi), with an orbital period of about 127 minutes. Objects below approximately 160 kilometers (99 mi) will experience very rapid orbital decay and altitude loss. With the exception of the manned lunar flights of the Apollo program, all human spaceflights have taken place in LEO (or were suborbital). The altitude record for a human spaceflight in LEO was Gemini 11with an apogee of 1,374.1 kilometers (853.8 mi). All manned space stations to date, as well as the majority of artificial satellites, have been in LEO.

LEO satellite system used in telecommunications.The satellite’s inclination depends on what the satellite was launched to monitor. The Tropical Rainfall Measuring Mission (TRMM) satellite was launched to monitor rainfall in the tropics. Therefore, it has a relatively low inclination (35 degrees), staying near the equator. TRMM’s low orbital inclination—just 35° from the equator—allows its instruments to concentrate on the tropics. This image shows one half of the observations TRMM makes in a single day.

Most scientific satellites and many weather satellites are in a nearly circular, low Earth orbit. LEOs are also used for data communication such as e-mail, paging and videoconferencing. Because LEOs are not fixed in space in relation to the rotation of the earth, they move at very high speeds and therefore data being transmitted via LEOs must be handed off from one satellite to the next as the satellites move in and out of range of the earth-bound transmitting stations that are sending the signals into space. Because of the low orbit, the transmitting stations do not have to be as powerful as those that transmit to satellites orbiting at greater distances from the earth's surface. LEO telecommunication systems are a promising technology because they provide the ability for underdeveloped territories to acquire satellite telephone service in areas where it is either too costly or not geographically possible to lay land lines.

Other uses of LEO

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Although the Earth's pull due to gravity in LEO is not much less than on the surface of the Earth, people and objects in orbit experience weightlessness because they are in free fall.

A low earth orbit is simplest and most cost effective for a satellite placement and provides high bandwidth and low communication latency.

Examples

Earth observation satellites and spy satellites use LEO as they are able to see the surface of the Earth more clearly as they are not so far away. They are also able to traverse the surface of the Earth. A majority of artificial satellites are placed in LEO, making one complete revolution around the Earth in about 90 minutes

The International Space Station is in a LEO about 400 km (250 mi) above the Earth's surface, Since it requires less energy to place a satellite into a LEO and the LEO satellite needs less powerful amplifiers for successful transmission, LEO is still used for many communication applications. Because these LEO orbits are not geostationary, a network (or "constellation") of satellites is required to provide continuous coverage. (Many communication satellites require geostationary orbits, and move at the same angular velocity as the Earth. Some communications satellites including the Iridium phone system use LEO.)

Lower orbits also aid remote sensing satellites because of the added detail that can be gained. Remote sensing satellites can also take advantage of sun-synchronous LEO orbits at an altitude of about 800 km (500 mi) and near polar inclination. ENVISAT is one example of an Earth observation satellite that makes use of this particular type of LEO.

Medium Earth orbit (MEO), sometimes called intermediate circular

orbit(ICO), is the region of space around the Earth above low Earth orbit (altitude of 2,000 kilometres (1,243 mi)) and below geostationary orbit (altitude of 35,786 kilometres (22,236 mi)).

The most common use for satellites in this region is for navigation, communication, and geodetic/space environment science. The most common altitude is approximately 20,200 kilometres (12,552 mi)), which yields an orbital period of 12 hours, as used, for example, by the Global Positioning System(GPS). Other satellites in Medium Earth Orbit include Glonass (with an altitude of 19,100 kilometres (11,868 mi)) and Galileo (with an altitude of 23,222 kilometres (14,429 mi)) constellations. Communications satellites that cover the North and South Pole are also put in MEO.

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The orbital periods of MEO satellites range from about 2 to nearly 24 hours.Telstar 1, an experimental satellite launched in 1962, orbits in MEO.

The orbit is home to a number of satellites. They have a larger capacity than LEOs. This enables them more flexibility in satisfying shifting market demands for voice or data services.A fleet of several MEO satellites, with orbits properly coordinated, can provide global wireless communication coverage. Because MEO satellites are closer to the earth than geostationary satellites, earth-based transmitters with relatively low power and modest-sized antennas can access the system. Because MEO satellites orbit at higher altitudes than LEO satellites, the useful footprint (coverage area on the earth's surface) is greater for each satellite. Thus a global-coverage fleet of MEO satellites can have fewer members than a global-coverage fleet of LEO satellites

In 1962, the first communications satellite, Telstar, was launched. It was a medium earth orbit satellite designed to help facilitate high-speed telephone signals, but scientists soon learned what some of the problematic aspects were of a single MEO in space. It only provided transatlantic telephone signals for 20 minutes of each approximately 2.5 hours orbit. It was apparent that multiple MEOs needed to be used in order to provide continuous coverage.

MEO’s are Communications satellites allow telephone and data conversations to be relayed through the satellite. Typical communications satellites include Telstar and Intelsat. The most important feature of a communications satellite is the transponder -- a radio that receives a conversation at one frequency and then amplifies it and retransmits it back to Earth on another frequency. A satellite normally contains hundreds or thousands of transponders. Communications satellites are usually geosynchronous (more on that later).

MEO Broadcast satellites broadcast television signals from one point to another (similar to communications satellites).

MEO Navigational satellites help ships and planes navigate. The most famous are the GPS NAVSTAR satellites.

HEO satellites:

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A highly elliptical orbit (HEO) is an elliptic orbit with a low-altitude (often under 1,000 kilometres (540 miles)) perigee and a high-altitude (often over 35,786 kilometers (19,323 miles)) apogee The 'highly elliptical' term refers to the shape of the ellipse, and to the eccentricity e of the orbit, not to the high apogee altitude.

Such extremely elongated orbits have the advantage of long dwell times at a point in the sky during the approach to, and descent from, apogee. Visibility near apogee can exceed twelve hours of dwell at apogee with a much shorter and faster-moving perigee phase. Bodies moving through the long apogee dwell can appear still in the sky to the ground when the orbit is at the right inclination, where the angular velocity of the orbit in the equatorial plane closely matches the rotation of the surface beneath. This makes these elliptical orbits useful for communications satellites.

While circular orbits may be the obvious solution for many satellites, elliptical orbits have many advantages for certain applications.

As a result of this many satellites are placed in elliptical orbits, especially where certain attributes are required. For example it does not require the orbits to be equatorial like the geostationary orbit. This means that polar and high latitude areas can be covered with highly elliptical orbits, HEO.

With the highly elliptical orbit described above, the satellite has long dwell time over one area, but at certain times when the satellite is on the high speed portion of the orbit, there is no coverage over the desired area. To solve this problem we could have two satellites on similar orbits, but timed to be on opposite sides of the orbit at any given time. In this way, there will always be one satellite over the desired coverage area at all times.

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If we want continuous coverage over the entire planet at all times, such as the Department of Defense's Global Positioning System (GPS), then we must have a constellation of satellites with orbits that are both different in location and time.

In this way, there is a satellite over every part of the Earth at any given time. In the case of the GPS system, there are three or more satellites covering any location on the planet.

The satellite elliptical orbit gives a number of coverage options that are not available when circular orbits are used.

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Highly elliptical orbit, HEO, applications

The highly elliptical satellite orbit can be used to provide coverage over any point on the globe. The HEO is not limited to equatorial orbits like the geostationary orbit and the resulting lack of high latitude and polar coverage.

As a result it ability to provide high latitude and polar coverage, countries such as Russia which need coverage over polar and near polar areas make significant use of highly elliptical orbits, HEO.

Sirius Satellite Radio uses HEO orbits to keep two satellites positioned above North America while another satellite quickly sweeps through the southern part of its 24-hour orbit. The longitude above which the satellites dwell at apogee in the small loop remains relatively constant as the earth rotates. The three separate orbits are spaced equally around the Earth, but share a common ground track.

Examples of HEO orbits offering visibility over Earth's Polar Regions, which most geosynchronous satellites lack, are:

Molniya orbits, named after the Molniya Soviet communication satellites which used them.

Tundra orbits

Much of Russia is at high latitude, so geostationary orbit does not provide full coverage of the region. These Soviet HEO orbits include polar coverage

Major differences between LEO, MEO & HEO satellite systems:

Parameter LEO MEO HEOSatellite Height 500-1500 km 5000-12000 km 35,800 kmOrbital Period 10-40 minutes 2-8 hours 24 hoursNumber of Satellites 40-80 8-20 3Satellite Life Short Long LongNumber of Handoffs High Low Least(none)

Gateway Cost Very ExpensiveExpensive Cheap

Propagation Loss Least HighHighest

GIS: A geographic information system (GIS) is a computer system for capturing, storing,

checking, and displaying data related to positions on Earth’s surface. GIS can show many

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different kinds of data on one map. This enables people to more easily see, analyze, and understand patterns and relationships.

With GIS technology, people can compare the locations of different things in order to discover how they relate to each other. For example, using GIS, the same map could include sites that produce pollution, such as gas stations, and sites that are sensitive to pollution, such as wetlands. Such a map would help people determine which wetlands are most at risk.

GIS can use any information that includes location. The location can be expressed in many different ways, such as latitude and longitude, address, or ZIP code. Many different types of information can be compared and contrasted using GIS. The system can include data about people, such as population, income, or education level. It can include information about the land, such as the location of streams, different kinds of vegetation, and different kinds of soil. It can include information about the sites of factories, farms, and schools, or storm drains, roads, and electric power lines

Data and GIS

Data in many different forms can be entered into GIS.

Spatial data: Describes the absolute and relative location of geographic features.Data that are already in map form can be included in GIS. This includes such information as the location of rivers and roads, hills and valleys.

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Attribute data: describes characteristics of the spatial features. These characteristics can be quantitative and/or qualitative in nature. Attribute data is often referred to as tabular data, Digital, or computerized, data can also be entered into GIS. An example of this kind of information is data collected by satellites that show land use—the location of farms, towns, or forests. GIS can also include data in table form, such as population information. GIS technology allows all these different types of information, no matter their source or original format, to be overlaid on top of one another on a single map.

Applications:

Street Network

o One of GIS's practical applications is street network control. Finding the right location when given an address is important to the postal service, police and fire departments, and it can be used to schedule vehicle-routing for transportation departments. It's also vital for developers in its capacity for site selection and analysis, as it provides relevant information about the quality of the site and geographical features that may, or may not, be desirable for builders. Street networks can also be employed in security-related activities when preparing evacuation routes.

Natural Resources

o GIS is employed in the natural resource management of rivers, recreational grounds, flooded areas, wetlands, farming lands, woodlands, and wildlife. It is used in Environmental Impact Analysis, scrutinizing the effect of various projects on the environment. GIS is involved in analyzing the hazards of toxins to land or

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groundwater. Water quality management is yet another GIS application, used to control wildlife habitats and to foresee the migration routes of animals.

Land

o GIS is employed in land management, as a tool for preparing zoning and land subdivision plans, and in mapping. Individuals, businesses and corporations can utilize GIS for examining the features of land lots. As GIS has direct access to information about land ownership, accuracy in land title transfers is also realized with this system.

Facilities Management

o GIS proves helpful in facilities management, as well as utility and construction companies, because of its ability to access the location of cables and pipes. Utility companies also use GIS to track energy use and to plan for improvements, and commercial property owners can use GIS to plan the maintenance of their facilities.

Crime Mapping:

o Crime mapping is used by analysts in law enforcement agencies to map, visualize, and analyze crime incident patterns.

Other applications include the use of GIS techniques for Water, Wastewater and Storm water systems, and in Solid Waste management, Networking, Transportation Engineering.

Future Launches At Kennedy Space Center:

Date: June 6

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Mission: SpaceX-4 Commercial Resupply Services flight with ISS-RapidScat

Launch Vehicle: Falcon 9

Launch Site: Cape Canaveral Air Force Station, Fla.

Launch Pad: Space Launch Complex 40

Description: SpaceX-4 will deliver cargo and crew supplies to the International Space Station. It will also carry the ISS-RapidScat instrument, a replacement for NASA's QuikScat Earth satellite to monitor ocean winds for climate research, weather predictions, and hurricane monitoring.

Date: July

Mission: Orbiting Carbon Observatory-2 (OCO-2)

Launch Vehicle: Delta II 7320

Launch Site: Vandenberg Air Force Base, Calif.

Launch Pad: Complex 2

Launch Window: 2:56 a.m. PDT, 1-second window

Description: OCO-2 is an Earth satellite mission to study carbon dioxide in the atmosphere and provide scientists with a better idea of the chemical compound's impacts on climate change.

Date: Sept. 12

Mission: SpaceX-5 Commercial Resupply Services flight with Cloud-Aerosol Transport System (CATS)

Launch Vehicle: Falcon 9

Launch Site: Cape Canaveral Air Force Station, Fla.

Launch Pad: Space Launch Complex 40

Description: SpaceX-5 will deliver cargo and crew supplies to the International Space Station. It will also carry CATS, a laser instrument to measure clouds and the location and distribution of pollution, dust, smoke, and other particulates in the atmosphere.

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Date: Dec. 5

Mission: SpaceX-6 Commercial Resupply Services flight

Launch Vehicle: Falcon 9

Launch Site: Cape Canaveral Air Force Station, Fla.

Launch Pad: Space Launch Complex 40

Description: SpaceX-6 will deliver cargo and crew supplies to the International Space Station.

What is the future of wireless telephony in Pakistan? What types of opportunities are available for entrepreneurs to invest money in wireless

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telephone industry? Give a comprehensive account of telecommunication jobs for telecom graduates in Pakistan and abroad?

Future of Wireless Telephony in Pakistan

The newly deregulated telecom sector in Pakistan took off and has elevated the national economy. From 2.1 phones per 100 Pakistanis in 1999, the number of fixed lines has crept up to 3 per 100 today. Share of telecom sector in Gross Domestic product (GDP) has also touched 1.9 per cent mark last year as compared to 1.6 per cent in 2001. Cellular subscribers in Pakistan reached 132,333,853 at the end of November 2013, as per stats made available by Pakistan Telecommunication Authority.

Currently in Pakistan the mobile companies are providing 2G(GSM) and 2.5G(GPRS, EDGE) services. After many years of investment and growth, the telecommunication industry is facing economic challenges, price wars and flat revenues. With nearly 100 million subscribers. Others argue that the country offers a lot more potential for information and telecommunication services. So new technologies and services will grab more and more subscriber towards wireless telephony.

Today, most of the telecom revenue comes from voice and to a small extent from value added services such as SMS and ringtone songs and news . Other data services such as mobile financial services, mobile web browsing, mobile social networking etc have not become popular in Pakistan and in other developing countries. Compare that with the rapid adoption of applications in EU and US on smart phones such as iPhone and BlackBerry and how that results in productivity, higher revenues and innovation.

Analysts agree that unless the conditions are right, consumers will not use the data services. Factors which impact the adoption of such services include: availability of high speed wireless networks, monthly cost, and availability of compatible handsets at affordable prices, availability of useful and interesting applications and content (preferably in local languages), literacy and awareness.

One of the discussion points from above is the lack of 3G networks in Pakistan. In simple terms, 3G is a network technology which allows for high speed wireless data services. It requires a certain frequency spectrum, which is managed by Pakistan Telecom Authority (PTA). It is usual for mobile companies to bid for the right to use the spectrum. The decision to offer 3G spectrums for auction rests with the Ministry of IT and Telecom.

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The dilemma is that 3G services come with a high infrastructure and spectrum acquisition cost. The mobile telecom companies in Pakistan contend that there are very few potential customers for this new technology and most of them are concentrated in a few large urban cities.

This point came up at a telecom conference in Lahore where stakeholders from industry, government and public presented their point of views. It was clear from the discussion that 3G have less to do with technology, more with adoption.

However, there are a number of improvements, which are possible with the existing 2G networks. EasyPaisais one of the examples where it solves a huge problem for a large section of the population. Telenor plans to offer advanced services including in the coming months expect more of such services from other telecom companies and allows the mobile applications which are being developed in Pakistan have good potential for both the local and international market. There’s also the need to support Urdu and other local languages, which has been ignored till now.

So if simply we summarize the above whole discussion then we can say that in Pakistan right now we cannot deploy the 3G wireless mobile networks due to the cost, lack of awareness in people, costly handset etc. People usually use wireless mobile phone services in Pakistan for voice calls (mostly in late night very low rate packages) and sms. People don’t use wireless mobile phones for browsing purposes for this they prefer the Internet services on laptops or computers which are very cheep in price and fast as well. So in future as per my research after 10 to 15 years the deployment of 3G networks can be thought. Currently all companies should provide services using existing 2G and 2.5G networks which should be easily adoptable by a common wireless mobile phone user in Pakistan.

Opportunities for Entrepreneurs to Invest Money in Wireless Telephone Industry of

Pakistan:

Telecom sector exhibited stability in the 2011 and invested $495.8 million with cellular mobile sector being the leading contributor.In addition, Universal Services Fund (USF) also invested Rs 3.5 billion in unserved areas.Besides this, telecom and Information Technology sector in the country is also looking for potential opportunities with the possible emergence of Third Generation (3G) technology in Pakistan in 2012.Hence The entrepreneurs are investing money by seeing the big opportunity in Pakistan.

Following are the opportunities available:

1) They can invest money in telecom service providing companies that are expected to introduce 3G in Pakistan such as Ufone and Zong.

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2) They can invest money in hardware vendors in Pakistan such as Huawei, Ericsson Pakistan.

Simply investment is possible in those network service providing companies which are moving towards 3G (investment should be long term because it will take some time to establish 3G in Pakistan if it is launched). Investment in current 2G or 2.5G mobile networks will not be more profitable and fruitful.

Telecom Jobs for Electrical Graduates in Pakistan and Abroad

1) Electrical Engineer III (Telecom) (HDQ)

2) VoIP Telecommunication Engineer3) 2G/3G RF Optimization Engineers4) 2G/3G Drive Test Engineers5) O&M Engineers6) RNO Experts7) Network Deployment Engineers8) Transmission Engineers9) Wireless Performance Engineers10) Wireless Performance Engineers11) Core Performance Engineers12) Voice Network Engineers13) Telephony System Engineers14) Cisco Analyst15) Network Integration Engineers

Most jobs are being offered by new network solution providing companies such as Netkom,Telenor, Zumbeel & Mobiserve etc.

In abroad specially in middle east the telecom engineers jobs are mostly offered by Huawie and Alcatel.

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Refrences:

www.urbanmapping.com

http://www.ehow.com/list_7606723_list-gis-applications.html#ixzz2zibH7XL

http://en.wikipedia.org

www.suparco.gov.pk

www.wisegeek.com/

www. nasa .gov

www. kennedy info.com/

http://www.nasa.gov/centers/kennedy/events/index.html

http://www.nbbd.com/events/nasa.html