École supérieure privée d'ingénierie et de technologie Prepared By: Boughattas Ahmed Chaieb Amal Année universitaire :

Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative 2 Content 1-Definiton 2-Historical 3-Application 5-Comparative 4-Technologies

1 -Definition 3 « The science of geolocation is concerned with the methods and concepts used to locate objects and features on the Earths surface, and in nearby space with respect to a terrestrial coordinate system. » Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

2-Historical 4 -Originally, the géolocation has been designed for the needs of the U.S. Army. In 1993, Bill Clinton decided to open this technique to the general public Services then appeared to locate objects, people, manage fleets of vehicles on a plan or map using geographic coordinates. -In recent years, the geolocation is democratized and is used mainly for road navigation Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

3-Application 5 Transport (navigation) Emergency (tracking wounded, rescue guide) Hospital (personnel, equipment) Safety (car theft) Geomarketing (stores) Traceability (commodity) Guide (library, museum) Military (missiles, troop movement) Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

4-Technologie 6 *Principal technologies used to positioning:  GPS  GSM  WiFi, Bluetooth  Internet Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

4-1)Internet,Adress IP 7 This technology, used in most cases on PC, is not very definite. She allows to determine the country in which is located but to find the region, it becomes a little more complicated Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

4-2)GSM 8 (Mobile Global System for Communications): this technology allows to locate a mobile phone by being based on certain information announced by the antennae GSM to which the terminal is linked. Global System Mobile (GSM) network is the most widely used. This means of wireless communication works by wave transmission between a base relay and the mobile phone user, covering an area of several kilometers. Geolocation which uses the GSM network consists of three different technologies, which are triangulation, the differential time, the system of the cell identification Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

9 What are these techniques? *The triangulation technique determines the position of a point as a function of signals from three antennas. The triangulation system is accurate to a better location. *The differential time: antennas receive signals surrounding the user device, the nearest transmits information received thereby locate. This is an external server that will calculate the location. *The system of the cell identification: the user is located by identifying the cell in which the communication is transmitted. This simple process is the least expensive. It locates the user to more or less 250 meters in urban areas, against a dozen kilometers in rural areas. Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

4-3)WIFI 9 WiFi geolocation has proved extremely popular and reliable with location-based services on smartphones that provide information to a user. All WiFi networks have a unique MAC address, however, this by itself is not helpful until the location of each MAC address has been mapped and added to a database. Once a database has been created it becomes possible to geolocate a user by determining which WiFi networks they are in range of at the time they are accessing an eCommerce service/web site. Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

4-4)GPS 10 How Does GPS Work? The Global Positioning System transmits signals from the satellites down to earth. A GPS receiver then picks up that transmission and analyzes the data that was sent. Mostly, the GPS receiver gathers the exact position of the satellite and determines the time it took for the signal to reach the receiver. With the distance measurements of several different satellite signals, the GPS receiver then uses the mathematical concept of triangulation to compute the exact location of the user. To accurately determine 2D information (longitude and latitude) a GPS receiver needs to be receiving signals from at least 3 satellites. To determine 3D information, the receiver needs to be picking up signals from 4 or more satellites which will enable it to determine more information such as exact location, elevation, altitude, distance traveled... Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

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12 A GPS receiver "knows" the location of the satellites because that information is included in the transmitted Ephemeris data.By estimating how far away a satellite is, the receiver also "knows" it is located somewhere on the surface of an imaginary sphere centred at the satellite. It then determines the sizes of several spheres, one for each satellite and therefore knows the receiver is located where these spheres intersect. Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

How Position is Determined 13 How Does GPS Work? The Global Positioning System transmits signals from the satellites down to earth. A GPS receiver then picks up that transmission and analyzes the data that was sent. Mostly, the GPS receiver gathers the exact position of the satellite and determines the time it took for the signal to reach the receiver. With the distance measurements of several different satellite signals, the GPS receiver then uses the mathematical concept of triangulation to compute the exact location of the user. To accurately determine 2D information (longitude and latitude) a GPS receiver needs to be receiving signals from at least 3 satellites. To determine 3D information, the receiver needs to be picking up signals from 4 or more satellites which will enable it to determine more information such as exact location, elevation, altitude, distance traveled... Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

How Position is Determined 14 Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

How Position is Determined 15 GPS Accuracy The accuracy of a position determined with GPS depends on the type of receiver. Most consumer GPS units have an accuracy of about +/-10m. Other types of receivers use a method called Differential GPS (DGPS) to obtain much higher accuracy. DGPS requires an additional receiver fixed at a known location nearby. Observations made by the stationary receiver are used to correct positions recorded by the roving units, producing an accuracy greater than 1 meter. How Is The Signal Timed? All GPS satellites have several atomic clocks. The signal that is sent out is a random sequence, each part of which is different from every other, called pseudo-random code. This random sequence is repeated continuously. All GPS receivers know this sequence and repeat it internally. Therefore, satellites and the receivers must be in synch. The receiver picks up the satellite's transmission and compares the incoming signal to its own internal signal. By comparing how much the satellite signal is lagging, the travel time becomes known. Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

How Position is Determined 16 What does the signal consist of? GPS satellites transmit two radio signals. These are designated as L1 and L2. A Civilian GPS uses the L1 signal frequency ( MHz) in the UHF band. The signals travel by line of sight, meaning they will pass through clouds, glass, plastic etc but will not travel through solid objects such as buildings and mountains. The GPS signal contains three different bits of information — a pseudo random code, almanac data and ephemeris data. The pseudo random code is simply an I. D. code that identifies which satellite is transmitting information. You can often view this number on your GPS unit's satellite information page, the number attached to each signal bar identifies which satellites it's receiving a signal from. Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

How Position is Determined 16 Almanac data is data that describes the orbital courses of the satellites. Every satellite will broadcast almanac data for EVERY satellite. Your GPS receiver uses this data to determine which satellites it expects to see in the local sky. It can then determine which satellites it should track. With Almanac data the receiver can concentrate on those satellites it can see and forget about those that would be over the horizon and out of view. Almanac data is not precise and can be valid for many months. Ephemeris data is data that tells the GPS receiver where each GPS satellite should be at any time throughout the day. Each satellite will broadcast its OWN ephemeris data showing the orbital information for that satellite only. Because ephemeris data is very precise orbital and clock correction data necessary for precise positioning, its validity is much shorter. It is broadcast in three six second blocks repeated every 30 seconds. The data is considered valid for up to 4 hours but different manufacturers consider it valid for different periods with some treating it as stale after only 2 hours. Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

5-Comparative advantagesdisadvantages GPSgood accuracyoutside only Urban areas problems GSM, UTMS Everyone has a phone Precision dependent density GSM relay WiFigood accuracy Uses existing network compatible terminals calibration Software customers to deploy Internetfreerequires basic geographic data (paying) 17 Definiton |Historical | Application | Technologie | Internet | GSM | WIFI | GPS | Comparative

20 18 Thank you questions ?