This document provides an overview of the Global Positioning System (GPS). It describes GPS as a satellite-based navigation system that uses 24 satellites to pinpoint the precise location, altitude, and time. It explains how GPS works by transmitting signals from the space segment satellites to receivers in the user segment. The signals allow receivers to calculate their position by determining the time difference of signals arriving from multiple satellites. The document outlines the key components of GPS including the signals, position determination process, receiver components, applications such as navigation, and future developments for GPS technology.

1. UNIVERSITY INSTITUTE OF
TECHNOLOGY(B.U)
Submitted by
Tanmoy Chakrabortty
Roll:- L2013-1074
Session:- 2012-2016
Computer Science And Engineering
GLOBAL POSITIONING
SYSTEM(GPS)

2. Content.
What is GPS (global positioning system).
How does GPS works?
GPS signals
Position determination
Block diagram of GPS receiver
Types of GPS systems
Applications of GPS
Future scope of GPS system
Conclusion
Reference

3. What is GPS (Global Positioning System)
GPS (Global Positioning system) is a type of GNSS(Global
Navigation Satellite System).
It is a "constellation" of 24 well-spaced satellites that orbit the
Earth and make it possible for people with ground receivers to
pinpoint their geographic location.
It allows small electronic receiver to determine the latitude
longitude and altitude of a point.
Receivers Calculated the precise time as well as position, which
can be used as a reference for scientific experiments.

4. How does GPS Works?
GPS system consist of three pieces
 Space Segment.
 Control Segment.
 User Segment.
The US Air force maintain these Segments.
Space Segment are the satellites that transmit the position
information.
Control Segment are the ground stations that are used to control the
satellites and update the information.
The User segment are the receiver that you purchased.

5. GPS Signals
 GPS satellites transmit two radio signals.
 The signals are mark as L1 and L2.
 A Civilian GPS uses the L1 signal frequency (1575.42 MHz)
in the UHF band.
 While the L2 frequency (1227.60 MHz) is used to measure the
ionospheric delay by Precise Positioning Service (PPS)
equipped receivers.
 All these signals travel by line of sight.
 The GPS signal contains three different bits of information
which are a pseudo random code, almanac data and ephemeris
data.

6. Position Determination
GPS satellite continually transmits messages containing the time the
message was sent. These signals travel at the speed of light through
outer space, and slightly slower through the atmosphere.

7. Useful form of these equations is in term of the
; n=1,2,3,4
Where
x, y, z = receiver’s coordinates
tc = time correction for the GPS receiver’s clock
n = satellite’s number
ttn = signal transmitted time for each satellite
trn = signal received time for each satellite
c = speed of light (3 x 108 m/s)
This mean, when there is four satellite used, there will be
four equation needed for the calculation.
The accuracy in this technique is about 1-5 meters.

8. Block Diagram of GPS Receiver

9. Types of GPS systems
1. Street navigation systems (SAT-NAV)
2. Sports GPS systems and watches
3. PDA based systems
4. Phones with GPS
5. For kids too

10. Applications of GPS
 The applications of the global positioning system fall into five
categories:
• Location
• Navigation
• Timing
• Mapping
• Tracking

11. Future scope of GPS System
1. GPS controlling Car (Without Driver)
2. In Defense For Accurate result for attack to enemy.
3. Shopping Cart.
4. Facilities for visually impaired.
5. More advanced Bi-function.
6. The virtual cable.

12. Conclusion
GPS is a fantastic tool of the 21st century offering many functions:
However, received information is not always reliable, and it would have
been interesting to see in which cases it is not. Furthermore, the space
segment is completely controlled by the American Army which enables
them to completely remove the satellite cover in certain countries in the
event of a war…
The future of GPS appears to be virtually unlimited; technological
fantasies abound. The system provides a novel, unique, and instantly
available address for every square yard on the surface of the planet–a new
international standard for locations and distances. To the computers of the
world, at least, our locations may be defined not by a street address, a city,
and a state, but by a longitude and latitude. With the GPS location of
services stored with phone numbers in computerized.

13. Reference
1. https://www.google.co.in/ For Search the topic and image.
2. National Research Council (U.S.). Committee on the Future
of the Global Positioning System; National Academy of
Public Administration (1995). The global positioning
system: a shared national asset: recommendations for
technical improvements and enhancements. National
Academies Press. p. 16. ISBN 0-309-05283-1. Retrieved
August 16, 2013.,
//books.google.com/books?id= FAHk65slfY4C&pg=PA16
3. https://gps2008.wordpress.com/ for topic GPS
4. https://en.wikipedia.org/wiki/Global_Positioning_System
5. www.gps.gov
6. http://www.slideshare.net