The GPS was developed by the US Department of Defense starting in 1969 to provide global navigation. By 1978, the first 4 satellites were launched, with full operational capability achieved in 1995. GPS uses a constellation of 24 satellites and the technique of triangulation to determine a user's precise three-dimensional position on Earth based on signal travel times from multiple satellites. It has both military and civilian applications such as navigation, mapping, tracking, and timing synchronization.

1. GLOBAL
POSTIONING
SYSTEM
Prepared By
Manthan Dhavne

2. History of the GPS
Developed by US Department of Defense
1969—Defense Navigation Satellite System (DNSS)
formed
 1973—NAVSTAR Global Positioning System
developed
 1978—first 4 satellites launched

3. History of the GPS(continued)
1993—24th satellite launched;
initial operational capability
1995—full operational
capability
 May 2000—Military accuracy
available to all users

4. What is GPS ?
GPS, which stands for Global Positioning System, is the only system today
able to show you your exact position on the Earth anytime, in any weather,
anywhere.
 GPS is the shortened form of NAVSTAR GPS. This is an acronym for
NAVigation System with Time And Ranging Global Positioning System.

5. What is GPS ?(continued)
GPS uses constellation of 24 satellites to determine the accurate three-
dimensional position of the user on the earth.
 GPS was originally designed for military use at any time anywhere on the
surface of the earth but soon after proposals it is made available to civilian users
also.

6. Signal From One Satellite
Signals From Two
Satellites
Three Satellites (2D
Positioning)
Three Dimensional (3D)
Positioning
TRIANGULATION
How it works ?

7. How it works ?(continued)
The GPS uses technique of "triangulation" to find location.
To "triangulate," a GPS receiver measures distance from the satellite using the travel time of
radio signals.
To measure travel time, GPS needs very accurate timing, which is provided by atomic clocks
used in the satellites.
Along with distance, we need to know exactly where the satellites are in space. This information
is obtained by Almanac data transmitted by satellites.
Finally we must correct for any delays the signal experiences as it travels through the
atmosphere.
To compute a positions in three dimensions. We need to have four satellite measurements. The
GPS uses a trigonometric approach to calculate the positions

8. Applications of GPS
 MILITARY
Navigation
Target tracking
Search and Rescue
 CIVILIAN Purposes
GPS for surveying
Mapping
Finding lost vehicles

9. Applications of GPS(continued)
 Mapping
 Environmental
 Agriculture
 Timings
synchronizing
 Marine