A Seminar on

GLOBAL POSITIONING SYSTEM(GPS)

By:

Pratik PatilM. Tech VLSI Design & Embedded Systems

KLES Dr. MSSCET, Belgaum

Contents

• What is GPS?• History• GPS Devices• Working• Applications• Advantages and Disadvantages

What is GPS?•The Global Positioning System(GPS) is a space based satellite navigation system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites.

•GPS was created and realised by the US department of defence and was originally run by 24 satellites.

HISTORY

• The design of GPS is based partly on similar ground-based radio navigation systems such as LORAN(LOng RAnge Navigation) and The Decca Navigator developed in 1940’s and used during WW II.

• Friedwardt Winterberg proposed a test of general relativity using accurate atomic clocks placed in orbit inside artificial satellite without which the GPS would not be possible.

GPS DEVICES•The GPS features three major components• Satellite system• The hand-held device called receivers.

•GPS satellites fly in circular or near circular orbits at an altitude of about 20,200 km and with a period of 12 hours. •Powered by solar cells, the satellites continuously orient themselves to point their solar panels toward the sun and their antenna toward the earth. •The GPS Receivers may be Hand held, Car in-built, Portable navigation, Marine GPS, etc.

WORKING

•Suppose the distance from Satellite A to our position is 11,000 miles• At this point we could be located anywhere on the specified sphereSatellite A

+

•Next, let us take another measurement from a second satellite, Satellite BSatellite B

+

•Now our position is narrowed down to the intersection of theses two sphere

Working

Satellite C+

Satellite A

Satellite B+

+•Taking another measurement from a 3rd satellite narrows our position down even further, to the two points

•So by ranging from 3 satellites we can narrow our position to just two points in space•More precise results can be acquired by considering measurement of the 4th satellite.

•These points are located where the 3rd sphere cuts through the intersection of first two spheres

APPLICATIONSOriginally a military project, GPS is considered a dual-use technology, meaning it has significant military and civilian applications.

The two main applications of the GPS systems in are • Navigation• Tracking

Vehicle Tracking System

Why Vehicle Tracking System?

•Fuel and Power Saving•Effective Fleet Control•Instantaneous Fuel Level Monitoring•Decreasing the Accident Risk•Driver and Load Security•Evaluation of Drivers Performance•Monitoring the Delivery Time•Safer Vehicle Renting

Vehicle Tracking System Logistics, Cargo, Distribution, TransportationFleet management

Public ServiceVTS avoids misusage

RailroadsVTS can monitor the wagons online

Private Yatches and Fishing Boats VTS locates the vehicle in case of emergency

School and EmploymentVTS can alert when vehicle is approaching

Working VehicleMonitoring vehicle which project they are working

PoliceCommunication with other vehicles

Rent a Car FirmsMonitor the vehicle in agreement terms

Advantages of GPS Systems•GPS is extremely easy to navigate as it tells you to the direction for each turns you take or you have to take to reach to your destination.• GPS works in all weather conditions.•The most attractive feature of this system is its100% coverage on the planet.•Due to its low cost, it is very easy to integrate into other technologies like cell phone.

Disadvantages•If you are using GPS on a battery operated device, there may be a battery failure and you may need a external power supply which is not always possible.•Sometimes the GPS signals are not accurate due to some obstacles to the signals such as buildings, trees, Mountains and sometimes by extreme atmospheric conditions such as geomagnetic storms.