global positioning system
DESCRIPTION
It depicts the basic information about GPS technology and its various uses in engineering and other fields. May be useful for students of engineering and for presentation.TRANSCRIPT
GLOBAL POSITIONING
SYSTEM
Presented by:
Himanshu Agrawal
•Contents
Introduction
What is GPS?
Components of GPS
Working Principle
Functioning of GPS
General Applications and Devices
Latest Innovations
Advantages
Disadvantages
Conclusion
Bibliography
•Introduction
The current system is managed by the U.S Air Force for the Department of Defense (DOD).
The current system became fully operational June 26, 1993 when the 24th satellite was lunched.
A minimum of four GPS satellite signals are required to compute positions in three dimensions and the time offset in the receiver clock.
•What is GPS? Global Positioning System Space-based satellite navigation system Provides location and time information In all weather, anywhere on or near the Earth Used to refer locations and help if you are lost. Secure cars, track your vehicles By sending SMS, making a missed call, preset
interval or GPS tracking software for real time online tracking
•Components of GPS
3 segments:
Space segment
Control segment
User segment
Space segment-Information The GPS uses a constellation of 24
satellites that orbit the earth at about 11,000 nautical miles, once every 12 hours.
The orbital position is constantly monitored and updated by the ground stations.
Each satellite is identified by number and broadcasts a unique signal.
Space segment cont.
Each satellite has 6 orbits. 3 satellites works for GPS, 4th satellite
work for accuracy.
3 satellites for 2d fix. Satellite orbital distance 20,000km. Orbital speed is 14,000km/hr 60 degrees apart and 55 degrees
with respect to equatorial plane. Use measurement of 4 satellites
Space segment-Satellite signals
Uses two types of signals to calculate distance
Code phase ranging
Carrier phase ranging
•Control SegmentThe ground segment of GPS(US) has one master control, one alternative master control station, 12 command and control antennas and 16 monitoring sites.
•User Segment
Consists of GPS receiver. The receiver collects and processes
signals from the GPS satellites. Use that information to determine and
display the location, speed, time and so on.
The accuracy and reliability is enhanced as the number of visible satellites increases.
•Working of GPS
Consist of two main components Receiver Location
Receiver
The receiver collects satellite signals, decodes and processes them.
The basic receiver does not include a transmitter.
Different levels of precision are available.
The receiver determines its location by trilateration.
GPS Trilateration Knowing its distance from
three satellites, the receiver
can determine its location
because there is only
two possible combinations
and one of them is out in space. In this example, the
receiver is located at b. The more satellite that are used,
the greater the potential
accuracy of the position location.
Location
Once the GPS receiver has located its position it is usually displayed in one of two common formats: Latitude and longitude
Universal transverse Mercator (UTM).
Latitude and Longitude
Latitudes and longitudes are angles.
Both use the center of the earth as the vertex, but they use a different zero reference.
UTM Zones The world is divided into 60 zones of latitude,
each 6 wide at the equator, that extend from 84 ⁰ ⁰N to 80 s.⁰
These zones begin at 180 longitude and are ⁰numbered consecutively eastward.
Dilution for Precision(DOP)
The more spread out the satellites are in the sky, the better the satellite geometry.
PDOP (position dilution of precision) is a combination of VDOP and HDOP.
The lower the PDOP value, the better the geometric strength.
Functioning of GPS
•General application
Banking mobile phone operations Auto toll GPS service GPS watch Google Map Navigation
Vehicle History Tracking or “Bread Crumbing”
Captures and stores a detailed GPS history of vehicle travel information.
Gain visibility into field operations for greater control .
Identify unproductive time in the field to increase overall productivity.
No need for wireless airtime to transmit data.
Route Guidance
Reduce unnecessary mileage and fuel costs by providing accurate driving directions.
Improve on time performance as drivers are less likely to get “lost” or follow inefficient routes.
Reduce vehicle engine idling time as driver lookup customer locations on maps.
Real Time Tracking
Improved management of dispatch and fleet activities.
Increased daily efficiency, productivity and accountability.
Added security for vehicles.
•Devices used in GPS
For Defence purposes
Road map devices
GPS on Mobile phones
Bicycle GPS devices
GPS equipped devices used for Engineering purposes
Use of GPS for Sports purposes
•Advantages of GPS
Easy to navigate Search nearby area Weather information Tracking Updated regularly
Easy to Navigate
Determine exactly
where you are at
any given moment. Give you the exact
latitude and
longitude
Search nearby area
Weather Information
Determine the atmosphere’s water content to improving the accuracy of weather forecasts
Tracking
•Disadvantages and Limitations
Need good care and handling Need external power Inaccuracy Potential failures Privacy concerns Geometry of satellite position Satellite clock errors SV position
Inaccuracy
Obstacles like buildings and trees can deflect the signal
Inaccuracy
•Conclusion GPS is very useful during adventures. GPS devices are perfect for water navigation. Though it has some limitation, it does not
considered as a big error. Because these errors are only nano errors. GPS is the most advanced, accurate,
commercially available and multi-use satellite navigation system that has ever been existed.
In military application it is the only system relied upon in providing data to very expensive guided weapons.
Refrences
http://www.kowama.de/en/gps http://www.aero.org/education/primers/
gps/ http://en.wikipedia.org/wiki/Global_Positi
oning_System Google
References (Photos) www.geotracing.com www.pcworld.com www.realsimple.com www.bike-advisor.com www.gorge.net.au www.stratcom.mil www.ircc.iitb.ac.in www.dcrainmaker.com www.bikebiz.com www.cultofmac.com openinvo.com www.telegraph.co.uk images.businessweek.com