How G.P.S finds location of the G.P.S receiver??

1. GLOBAL POSITIONING SYSTEM
By B.M.G.Prakash Rao

2. • What is G.P.S?
• G.P.S SEGMENTS
• HOW G.P.S DETERMINES A LOCATION?
• G.P.S SIGNAL ERRORS
• CONCLUSION

3. • G.P.S stands for GLOBAL POSITIONING SYSTEM
• A space based satellite Navigation system
• It is developed by U.S.D.O.D

4. • It comprises of three segments
1.Space segment
2.Control segment
3.User segment

6. Things which need to be determined:
1. Current location of G.P.S satellites
2. Distance between receiver’s position
and G.P.S satellites

7. Satellite B
+
Satellite A
+
• Distance measurements
from 2 satellites limits our location to the
intersection of 2 spheres,which is a
Circle…

8. Satellite A
Satellite B
+
+
Satellite C
+
• Taking another measurement from a
3rd satellite narrows our position down
even further to two points….
• So , by ranging from 3
satellites we can narrow our
position to just two points in
space
• G.P.S receivers use a
4th satellite to precisely locate
our position

10. • Different errors can cause a deviation of +/- 50-100 meters
from actual G.P.S receiver position which are:
1. Satellite clock: One nano-second of inaccuracy in a
satellite clock results in about 30 cm of error…….
2. Receiver clock : Any error in receiver clock causes
inaccuracy in distance measurement…
3. G.P.S Jamming: It limits the effectiveness of the G.P.S
signal

11. CONCLUSION
• G.P.S,A Satellite based navigation system
can be used to determine the position
of any object on earth
• It’s application field is very large and
new applications will continue to be
created like GLONASS and GALILEO
as the technology evolves….