(GPS) technology is a great boon to anyone who has the need to navigate either great or small distances. The Global Positioning System (GPS) is a burgeoning technology, which provides unequalled accuracy and flexibility of positioning for navigation, surveying and GIS data capture.

1. Prepared By
Prof. Ashish Makwana
Civil Engg. Dept.
Prof. Ashish Makwana 1

2. PRESENTATION OUTLINE…
•Introduction
•Why do we need GPS?
•GPS Basics
•How does The GPS Work?
•Parts of a GPS System
•GPS Applications
•GPS - Components and Basic Facts
•GPS Positioning Types
•GPS Setup Block Diagram
•Factors That Affect GPS
Prof. Ashish Makwana 2

3. INTRODUCTION
• (GPS) technology is a great boon to anyone who has the need
to navigate either great or small distances.
• The Global Positioning System (GPS) is a burgeoning
technology, which provides unequalled accuracy and
flexibility of positioning for navigation, surveying and GIS
data capture.
3Prof. Ashish Makwana

4. WHY DO WE NEED GPS?
• Trying to figure out where you are is probable man’s oldest
pastime.
• Finally US Dept of Defense decided to form a worldwide
positioning system.
• Also known as NAVSTAR ( Navigation Satellite Timing and
Ranging Global positioning system) provides instantaneous
position, velocity and time information.
4Prof. Ashish Makwana

5. G. P. S. BASICS
• In relation to a well-defined coordinate system, usually by
three coordinate values and
• In relation to other point, taking one point as the origin of a
local coordinate system.
5Prof. Ashish Makwana

6. HOW DOES THE GPS WORK?
• Requirements
• Triangulation from satellite
• Distance measurement through travel time of radio signals
• Very accurate timing required
• To measure distance the location of the satellite should also be known
• Finally delays have to be corrected
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7. PARTS OF A GPS SYSTEM
7Prof. Ashish Makwana

8. GPS APPLICATIONS
• Surveying and Mapping
• Navigation
• Remote Sensing and GIS
• Geodesy
• Military
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9. GPS - COMPONENTS AND BASIC FACTS
• Triangulation from the satellite is the basis of the system.
• To triangulate, the GPS measures the distance using the
travel time of the radio message.
• To measure travel time, the GPS need a very accurate clock.
• Once the distance to a satellite is known, then we need to
know where the satellite is in space.
• As the GPS signal travels through the ionosphere and the
earth's atmosphere, the signal is delayed.
9Prof. Ashish Makwana

10. GPS POSITIONING TYPES
• Absolute Positioning
• Differential Positioning
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11. GPS SETUP BLOCK DIAGRAM
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12. FACTORS THAT AFFECT GPS
• Number of satellites - minimum number required
• Multipath - reflection of GPS signals near the antennae
• Ionosphere - change in the travel time of the signal
• Troposphere - change in the travel time of the signal
• Satellite Geometry - general distribution of the satellites
• Satellite Health - Availability of Signal
• Signal Strength - Quality of Signal
• Distance from the Reference Receiver
• Radio Frequency (RF) Interference
• Loss of Radio Transmission from Base
12Prof. Ashish Makwana

13. THANK YOU
13Prof. Ashish Makwana