The document provides an overview of Global Positioning System (GPS) technology, detailing its introduction, components, and functioning mechanisms. It discusses various applications of GPS, such as in aviation, space, and mapping, while also addressing its limitations and future developments planned like GPS III. Enhanced features are highlighted, including improved reliability, accuracy, and new signal types aimed at supporting critical operations.

1. Global Positioning System
(GPS)
WDN Presentation
CSN - SLIIT
GPS Technology
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2. Team Members
1. Sachin Thishnika
2. Kusal Indika
3. Vidusha Rathnayaka
4. Nadeendra Yashaswin
5. Janaka Poddalgoda (Absent)
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3. Content
1. Introduction
2. What is GPS ?
3. How GPS Works
4. Applications of GPS
5. Drawbacks of GPS
6. Future Development
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4. Introduction
Navigation in early days
 North Star
 Compass
 LORAN & Decca Navigator
GPS project
 Developed under Department of Defense
GPS is not alone
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5. What is GPS ?
Global Navigation Satellite System (GNSS)
Provide
 Position
 Timing
 Navigation
Three segments
 Space
 Control
 User
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6. What is GPS ? Cont.
Space segment
 24 satellites
 At least six satellites on LOS
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7. What is GPS ? Cont.
Control Segment
 Operate by US Air force
 Consist of
•
•
•
•
Master Control Segment (MCS)
Alternative MCS
Dedicated ground antennas
Monitoring stations
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8. What is GPS ? Cont.
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9. What is GPS ? Cont.
User segment
 Consist of GPS receivers
 Calculate location using GPS signals
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10. How GPS Works
Satellite emit two signals




L1 (1575.42 MHz) UHF band – civil use
L2 – (1227.60 MHz) - Military use
Power 50w
CDMA
GPS signal
 Pseudo random code
 Almanac data
 Ephemeris data
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11. How GPS Works
• Beacon –Radio Signal
• Travel time(t)=Sync of receive time – Satellite Time
•
d=C*t
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12. How GPS Works Cont.
Triangulating
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13. Applications of GPS
GPS is an essential element of the global
information infrastructure
It’s
 Free
 Open
 Dependable
“New uses of GPS are invented every day and
are limited only by the human imagination.”
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14. Applications of GPS cont.
Aviation
 Cost effective solution
 Increase the safety and efficiency
 Three-dimensional positioning
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15. Applications of GPS cont.
Space
 Navigation solutions
 Altitude solutions
 Timing solutions & etc.
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16. Applications of GPS cont.
Survey & mapping
 Accuracy
 Reliability
 Interoperability
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17. Applications of GPS cont.
Differential GPS
 10 meters to 10 centimeters
 Base station in known location
 Real-time DGPS
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18. Drawbacks of GPS
Signal multipath
Atmospheric effect
No GPS signals in
 Indoor
 Under water
 Under ground
Attacks
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19. Future Development
GPS III




Enhanced signal reliability & accuracy
L1C signal
L2C signal
Schedule to launch in 2015
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20. Future Development Cont.
No Selective Availability (SA)
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21. Future Development Cont.
L5 “safety-of-life” signal
 Two times powerful as L2C
 Focus on aviation & transportation
 Resistant to jamming & interference
High gain directional antenna
 100 times more powerful than wide angle
antenna
 M-coded military signal
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22. Future Development Cont.
Cross platform receivers
 More accurate
 Fast convergence
GPS & GLONASS satellites
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23. GPS Technology
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24. GPS Technology
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