1. Principles of Global PositioningPrinciples of Global Positioning
Systems and Its ApplicationsSystems and Its Applications

2. Introduction
The global positioning system(GPS) is a network of
24 NAVSTAR satellites orbiting at a distance of 20,200kms
from the surface of the earth . Originally established by the
u.s department of defense(DOD).
The system”s positioning and timing data are used
for a variety of applications, including air,land and sea
navigation, vehicle and vessel tracking,surveying and
mapping ,asset and natural Resource management.
GPS is the shortened form of NAVSTAR GPS. This
is an acronym for Navigationsystem with Time and Ranging.

3. Historical Development of GPS
1978 -Launch of first GPS satellite
1985 -Kinematic GPS surveying
1989 -Launch of first Block II satellite
Wide area differential GPs concept
U.S Coast Guard GPSInformation System (GPSIC)
1993 -Real-time Kinematic GPS
Initial operational capability (IOC)on December 8.
1995 -Full operational capability (FOC) on July 17
1996 -Presendential Decision Directive, first U.S GPS policy
2000 - Selective availability set to Zero .

4. Satellites orbiting the Earth

5. System Overview:System Overview:
The total GPS configuration is comprised of three distinctThe total GPS configuration is comprised of three distinct
segmentssegments
(1) The space segment-Satellites orbiting the Earth(1) The space segment-Satellites orbiting the Earth
(2) The control segment-Stations positioned on the Earth’s(2) The control segment-Stations positioned on the Earth’s
equator to control the satellites.equator to control the satellites.
(3) The user segment – Anybody that receives and uses the(3) The user segment – Anybody that receives and uses the
GPS signal.GPS signal.

6. Basic principles of GPSBasic principles of GPS
ResectionResection
Four unknownsFour unknowns
Calculating the distance to the satelliteCalculating the distance to the satellite
Calculating timeCalculating time

7. Errors and precisionErrors and precision
Ionospheric and atmospheric delaysIonospheric and atmospheric delays
Satellite and Receiver clock errorsSatellite and Receiver clock errors
Dilution of precisionDilution of precision
MultipathMultipath
BlendersBlenders

9. Factors affecting accuracyFactors affecting accuracy
Number of visible satellitesNumber of visible satellites
Position dilution of precisionPosition dilution of precision
Satellite elevationsSatellite elevations
MultipathMultipath
Distance between space station and roverDistance between space station and rover
receiversreceivers

10. Differentially corrected positionsDifferentially corrected positions
DGPSDGPS

11. Surveying with GPSSurveying with GPS
Advantages using GPSAdvantages using GPS
Limitations of GPSLimitations of GPS
Uses of GPS technologyUses of GPS technology

12. Uses of GPS technologyUses of GPS technology
 Location - Determine a basic positionLocation - Determine a basic position
 Navigation - Getting from one location to anotherNavigation - Getting from one location to another
 Tracking-Monitoring the movement of peopleTracking-Monitoring the movement of people
and thingsand things
 Mapping-Creating mapsMapping-Creating maps
 Timing-Providing precise timingTiming-Providing precise timing

13. Competitors of GPSCompetitors of GPS
GLONASSGLONASS
- Russian Federation’s satellite- Russian Federation’s satellite
navigation systemnavigation system
• GalileoGalileo
-European Union and the European Space-European Union and the European Space
AgencyAgency

14. A GPS Signal contains three different bits of information
(1).Pseudo random code
(2).Ephemeris data
(3).Almanac data

15. Conclusion
GPS was originally designed for military use at
any time, anywhere on the surface of the earth.
The civilians may also use GPS to marine navigation,
car navigation and surveying.

16. THANK YOUTHANK YOU