Global Positioning SystemGlobal Positioning SystemGPSGPS

Tanta University Faculty of Science

Department of Geology

Submitted byMohamed Mahmoud Ahmed El-shora

Supervised ByProf. Dr. Shadiya Taha El-khodary

11/13/201211/13/2012 11

Global Positioning SystemGlobal Positioning System

11/13/201211/13/2012 22

IntroductionIntroduction Global Positioning System or Global Positioning System or

GPSGPS is a constellation of 27 is a constellation of 27 satellites orbiting the earth at satellites orbiting the earth at about 12000 miles. about 12000 miles. These These satellites are continuously satellites are continuously transmitting a signal and anyone transmitting a signal and anyone with a GPS receiver on earth with a GPS receiver on earth can receive these transmissions can receive these transmissions at no charge.at no charge. By measuring the By measuring the travel time of signals transmitted travel time of signals transmitted from each satellite, a GPS from each satellite, a GPS receiver can calculate its receiver can calculate its distance from the satellitedistance from the satellite. . Satellite positions are used by Satellite positions are used by receivers as precise reference receivers as precise reference points to determine the location points to determine the location of the GPS receiver. of the GPS receiver.

11/13/201211/13/2012 33

IntroductionIntroduction . If a receiver can receive . If a receiver can receive

signals from at least 4 signals from at least 4 satellites, it can determine satellites, it can determine latitude, longitude, altitude latitude, longitude, altitude and time. and time. If it can receive If it can receive signals from 3 satellites, it signals from 3 satellites, it can determine latitude, can determine latitude, longitude and time. The longitude and time. The satellites are in orbits such satellites are in orbits such that at any time anywhere that at any time anywhere on the planet one should on the planet one should be able to receive signals be able to receive signals from at least 4 satellites.from at least 4 satellites.

11/13/201211/13/2012 44

Global Positioning SystemGlobal Positioning SystemGPSGPS

The Global Positioning System The Global Positioning System (GPS)(GPS) is a space-based global is a space-based global navigation satellite system navigation satellite system (GNSS)(GNSS)

GPS is a satellite systemGPS is a satellite system which which enables anyone with a GPS enables anyone with a GPS receiver to establish their receiver to establish their position, altitude and speed. It position, altitude and speed. It was developed by the USA and was developed by the USA and can be used by anyone. can be used by anyone.

In this picture: Artist's In this picture: Artist's conception of GPS Block II-F conception of GPS Block II-F satellite in orbitsatellite in orbit

GPS Satellite NASA art-ii-f

11/13/201211/13/2012 55

Comparison of GNSS systemsComparison of GNSS systems SystemSystem CountryCountryNumber ofNumber of

satellitessatellites Orbital Orbital

height &height & periodperiod

GPSGPS United United StatesStates

≥ ≥2424))24-3224-32((

20,20020,200  km, km, 12.0h12.0h

COMPASSCOMPASSChinaChina 3535 21,15021,150  km, km, 12.6h12.6h

GALILEOGALILEO European European UnionUnion

222223,22223,222  km, km, 14.1h14.1h

GLONASSGLONASS RussiaRussia 242419,10019,100  km, km, 11.3h11.3h

Core Satellite navigation systems, currently GPS, Galileo and Core Satellite navigation systems, currently GPS, Galileo and GLONASS.GLONASS.11/13/201211/13/2012 66

Global Positioning SystemGlobal Positioning SystemGPSGPS

Consists of two main parts,

the transmitter and receiver

Part of the sender are those satellites, but receiver devices are small hands very sophisticated work in electronic circuits called Microprocessor

The location is determined in two ways:

First by the so-called Doppler Shift of the electromagnetic waves received from the satellite, and the displacement caused by the relative speed between the Earth and satellite

The second way to determine the location based on measuring the time delay between the electromagnetic waves received from satellites.

11/13/201211/13/2012 77

Measuring DistanceMeasuring Distance

A GPS receiver determines its position by using the signals that it observes from different satellites. Since the receiver must solve for its position (X, Y, Z) and the clock error (x), four SVs are required to solve receiver's position using the following

four equations:

Where (x1,y1) (x2,y2) (x3,y3) and (x4, y4) stand for the location of satellites and R1, R2, R3, R4 are the distances of satellites from the receiver position (Figure-3).

Hence solving the four equations for four unknowns X, Y, Z and x, the position or location of the station is

calculated .11/13/201211/13/2012 88

Global Positioning SystemGlobal Positioning SystemGPSGPS

The analysis of these data by the GPS devices that contain software provider a lot of information and physical variables such as the impact the atmosphere on electromagnetic waves, as well as the influence of gravity and the situation of climate, as the program contains detailed maps of the land, cities and streets, where, and the most important geographical features and other information important.

It could be argued that the system of Global Positioning System GPS is based on an integrated system of satellites that operate within a system called Sophisticated Network Of Satellites, and these satellites will scan the globe twice every 23 hours and 56 minutes, as distributed these satellites on 6 levels of rotation of each level makes 55 degrees with the other level, and in each level there are three satellites.

11/13/201211/13/2012 99

11/13/201211/13/2012 1010

GPSGPS

11/13/201211/13/2012 1111

Models for GPSModels for GPS

11/13/201211/13/2012 1212

Models for GPSModels for GPS

11/13/201211/13/2012 1313

GPS MAPGPS MAP

11/13/201211/13/2012 1414

GPS Maps Of EgyptGPS Maps Of Egypt

11/13/201211/13/2012 1515

Structure of GPSStructure of GPSGPS consists of three parts:

the space segment,

the control segment,

and the user segment.The space segment is composed of 24 to 32 satellites in medium

Earth orbit ,These space vehicles (SVs) send radio signals from space.Their configuration provides user with between five and eight

SVs visible from any point on the earth.

11/13/201211/13/2012 1616

Structure of GPSStructure of GPS The control segment is

composed of a master control station, an alternate master control station & a host of dedicated & shared ground antennas & monitor stations.

The Control Segment consists of a system of tracking stations located around the world.These stations measure signals from the SVs, compute orbital data, upload data to the SVs, then the SVs send data to GPS receivers over radio signals.

11/13/201211/13/2012 1717

Structure of GPSStructure of GPS The The User SegmentUser Segment consists of consists of

the GPS receivers and the user the GPS receivers and the user community.community. – GPS receivers convert SV signals GPS receivers convert SV signals

into position, velocity, and into position, velocity, and time estimates.time estimates.

– Four satellites are required to Four satellites are required to compute the four dimensions of compute the four dimensions of X, Y, Z (position) and T (time).X, Y, Z (position) and T (time).

GPS receivers are used for GPS receivers are used for navigation, surveying, time navigation, surveying, time dissemination, and other dissemination, and other research.research.

Navigation receivers are Navigation receivers are

made for aircraft, ships, made for aircraft, ships, ground vehicles, and for ground vehicles, and for hand carrying by individuals.hand carrying by individuals.

11/13/201211/13/2012 1818

11/13/201211/13/2012 1919

11/13/201211/13/2012 2020

GPS StructureGPS Structure

11/13/201211/13/2012 2121

Uses Of GPSUses Of GPSThere are many uses of this system are difficult to restrict, at the present time, proceeded a lot of companies, global transportation and shipping companies manufactured to follow the movement of machinery and vessels by this system very effective, as has been the introduction of this system in a lot of cars newly, which provides drivers for detailed maps of places and streets where they are located, and the best and shortest routes, which should conduct during their movements daily.

Also saw this system for other uses by the airlines and air navigation to guide planes in the sky very precisely, and most recently was the introduction of this system in monitoring systems, air and track hurricanes, wind and waves raging in the oceans, as used by the bodies of scientific research to track migration birds, aquatic and forest fire monitoring and movement of icebergs.

11/13/201211/13/2012 2222

Uses Of GPSUses Of GPS

11/13/201211/13/2012 2323

Applications of GPSApplications of GPS

GPS has become a widely GPS has become a widely used and useful tool for used and useful tool for commerce, scientific uses, commerce, scientific uses, tracking and surveillance. tracking and surveillance. GPS's accurate timing GPS's accurate timing facilitates everyday activities facilitates everyday activities such as banking, mobile such as banking, mobile phone operations, and even phone operations, and even the control of power grids. the control of power grids. Farmers, surveyors, Farmers, surveyors, geologists and countless geologists and countless others perform their work others perform their work more efficiently, safely, more efficiently, safely, economically, and accuratelyeconomically, and accurately. .

11/13/201211/13/2012 2424

Applications of GPSApplications of GPS

11/13/201211/13/2012 2525

11/13/201211/13/2012 2626