Global Positioning System(GPS)Global Positioning System(GPS)

Course TeachersCourse Teachers

Dr. Muhammad Ahsan UllahDr. Muhammad Ahsan Ullah

&&

Mr. Rashed Md. Murad HasanMr. Rashed Md. Murad Hasan

This was presented as a coursework of Electronic Communication Sessional in Level 3, Term 1.

Correspondence: amimul66@gmail.com

PRESENTED BY

Md.Hasanul Azim (1002061)Sakib Reza (1002062)Md. Adibul Islam (1002063)Rajib Ghose (1002064)Irfan Uddin (1002065)Md. Amimul Ehsan (1002066)

Correspondence: amimul66@gmail.com

Objectives: Objectives:

To observe the GPS Module.To observe the GPS Module.Creating waypoints by the GPS.Creating waypoints by the GPS.To determine Elevation & Location using To determine Elevation & Location using

the GPS.the GPS.

Lab Experiment Requried Lab Experiment Requried InstrumentInstrument

GARMIN eTREX GARMIN eTREX

(GPS)(GPS)Two batteriesTwo batteries

What is the GPS?What is the GPS?

A network of satellite that continuously A network of satellite that continuously transmit coded information which makes it transmit coded information which makes it possible to precisely identify locations on possible to precisely identify locations on earth is called a GPS.earth is called a GPS.

Components of the GPS SystemComponents of the GPS System

GPS

Space Segment Control Segment User Segment

Space SegmentSpace Segment

24 satellite vehicles24 satellite vehicles Six orbital planesSix orbital planes

Inclined 55Inclined 55o o with respect to with respect to equatorequator

Orbits separated by 60Orbits separated by 60oo

20,200 km elevation 20,200 km elevation above Earthabove Earth

Orbital period of 11 hr 55 Orbital period of 11 hr 55 minmin

Five to eight satellites Five to eight satellites visible from any point on visible from any point on EarthEarth

Control SegmentControl Segment

Monitor stationsMonitor stationsMaster control stationMaster control station

Schreiber AFB, ColoradoSchreiber AFB, Colorado

Ground antennasGround antennas

GPS Ground Control StationsGPS Ground Control Stations

User segmentUser segment

GPS antennas GPS antennas ReceiverReceiver ProcessorsProcessors Precise timingPrecise timing Used byUsed by

AircraftAircraft Ground vehiclesGround vehicles ShipsShips IndividualsIndividuals

GPS Communication and ControlGPS Communication and Control

How does the GPS work?How does the GPS work?

GPS works by receiving signals from special satellites that orbit the earth twice a day at an altitude of about 13 thousand miles.

A minimum no. of 24 satellites are required for the GPS to function, but there are usually 33 satellites circulating the glob in case of ones fails.

http://youtu.be/8sHDEUe1pY4

GPS satellites continuously emits RF signal that provides two signals of information :1.the current time 2. where exactly about the earth the sat is at that timeGPS receivers use this information to do a special calculation called triangulation

http://youtu.be/HjRgfFSA-yU

The receivers compare the time the signal was sent from the The receivers compare the time the signal was sent from the satellite with the time the signal was received.satellite with the time the signal was received.

The difference in the time indicates the distance between the The difference in the time indicates the distance between the receiver and the satellite.receiver and the satellite.

http://youtu.be/0jrvliE3rX4

A GPS receiver needs to get signals from three satellites to calculate latitude and longitude.It needs the signal from 4th sat to calculate the altitude.

http://youtu.be/xfzKu0a0RaA

According to Einstein’s theory of relativity-According to Einstein’s theory of relativity-

Time dilation occurs in satellite with respect Time dilation occurs in satellite with respect to ground which is reduced by using Atomic to ground which is reduced by using Atomic Clock.Clock.

Atomic clock is an extremely accurate type Atomic clock is an extremely accurate type of clock that is regulated by the vibrations of of clock that is regulated by the vibrations of an atomic or molecular system such as an atomic or molecular system such as cesium or ammonia.cesium or ammonia.

Triangulation is a process by which the location of a radio transmitter can be determined of a three dimensional point.

Working ProcedureWorking Procedure

Working Procedure:Working Procedure:

Creating Waypoints Using the Map:Creating Waypoints Using the Map:To create a waypoint using the Map page:To create a waypoint using the Map page:

1. On the Map page, use the ROCKER to move the pointer to the 1. On the Map page, use the ROCKER to move the pointer to the map item you want to mark. map item you want to mark.

2. Press release the ROCKER to capture the pointer location and 2. Press release the ROCKER to capture the pointer location and open the information page for the map item. open the information page for the map item.

3. Select Save. If there is no information for that point, a 3. Select Save. If there is no information for that point, a

““No map information at this point. Do you want to create a user No map information at this point. Do you want to create a user waypoint here?” prompt appears. Select Yes.waypoint here?” prompt appears. Select Yes.

Working Procedure:Working Procedure:

Marking Current Location:Marking Current Location:Press in and hold the ROCKER to mark current location for Press in and hold the ROCKER to mark current location for creating a new waypoint. There must be a valid position to mark creating a new waypoint. There must be a valid position to mark current location.current location.To mark current location the following procedure is followed:To mark current location the following procedure is followed:a. a. Press & hold the ROCKER until the Mark waypoint page Press & hold the ROCKER until the Mark waypoint page appears. A default three digit name and symbol are assigned to appears. A default three digit name and symbol are assigned to the new waypoint.the new waypoint.b. b. To accept the waypoint with the default information, select OK.To accept the waypoint with the default information, select OK.

Data and CalculationData and Calculation

Waypoint 1: Waypoint 1:

Latitude: N22º27.770Latitude: N22º27.770΄́

Longitude: E91º58.312Longitude: E91º58.312΄́

Elevation: 101Elevation: 101

Waypoint 2:Waypoint 2:

Latitude: N22º27.782Latitude: N22º27.782΄́

Longitude: E91º58.310Longitude: E91º58.310΄́

Elevation: 90Elevation: 90

Data and CalculationData and Calculation

Distance between two waypoint 01 & 02:Distance between two waypoint 01 & 02:

Latitude: dN=0.0002ºLatitude: dN=0.0002º

Longitude: dE=0.00033ºLongitude: dE=0.00033º

so distance= 36.53 mso distance= 36.53 m

[Lat- 1º=110.64km[Lat- 1º=110.64km

Lon- 1º=107.55km]Lon- 1º=107.55km]

Application of GPS TechnologyApplication of GPS Technology

Application of GPS TechnologyApplication of GPS TechnologyLocationLocation

NavigationNavigation

TrackingTracking

MappingMappingDetermining a basic positionDetermining a basic position

Getting from one location to anotherGetting from one location to another Creating maps of the worldCreating maps of the world

Monitoring the movement of thingsMonitoring the movement of things

Vehicle controlVehicle control Driving carDriving carSurveySurveyDetermination of Determination of latitudelatitude longitudelongitude altitudealtitude

Application of GPS TechnologyApplication of GPS Technology

Operation in Desert StormOperation in Desert Storm GPS is widely used in the militaryGPS is widely used in the military VehiclesVehicles AircraftAircraft Marine vesselsMarine vessels

GPS Uses for the MilitaryGPS Uses for the Military

ACCURACY AND LIMITIONSACCURACY AND LIMITIONS

ACCURACY AND LIMITIONSACCURACY AND LIMITIONS

Some factors affecting accuracy of GPS Some factors affecting accuracy of GPS

Input errorsInput errorsDilution of precisionDilution of precisionSD(position)= DOP*SD(position)= DOP* SD(inputs)SD(inputs)DOP can be improved DOP can be improved by more satellites.by more satellites.Inputs improved by DGPSInputs improved by DGPS

ACCURACY AND LIMITIONSACCURACY AND LIMITIONS

GPS signal can be reflected by objectsGPS signal can be reflected by objectsbefore reaching to receiver.before reaching to receiver.

Signal delay caused by Ionosphere and Signal delay caused by Ionosphere and

TroposphereTroposphere

Orbit errorsOrbit errors

ConclusionConclusion

The technology of the GPS is allowing for hugeThe technology of the GPS is allowing for huge

changes in society . The cost of receiver ischanges in society . The cost of receiver is

dropping and at the same time the accuracy of dropping and at the same time the accuracy of

the system is improving.the system is improving.

THANK YOUTHANK YOU