Upload File

gps introduction

65
Introduction to the Global Positioning System S.M.J.S.Samarasinghe Superintendent of Surveys Institute of Surveying and Mapping Diyatalawa - Sri Lanka.

Upload: jayantha-samarasinghe

Post on 14-Apr-2017

341 views

Category:

Education


0 download

Report

TRANSCRIPT

Page 1: GPS introduction

Introduction to the Global Positioning System

S.M.J.S.SamarasingheSuperintendent of Surveys

Institute of Surveying and MappingDiyatalawa - Sri Lanka.

Page 2: GPS introduction

What is the GPS?Orbiting navigational satellites

Transmit position and time dataHandheld receivers calculate

latitudelongitudealtitudevelocity

Developed by Department of Defense

Page 3: GPS introduction

History of the GPS1969—Defense Navigation Satellite

System (DNSS) formed1973—NAVSTAR Global Positioning

System developed1978—first 4 satellites

launchedDelta rocket launch

Page 4: GPS introduction

History of the GPS 1993—24th satellite

launched; initial operational capability

1995—full operational capability

May 2000—Military accuracy available to all users

Page 5: GPS introduction

Components of the System

Page 6: GPS introduction

GPS Communication and Control

Page 7: GPS introduction

Components of the SystemSpace segment 24 satellite vehicles Six orbital planes

Inclined 55o with respect to equator

Orbits separated by 60o

20,200 km elevation above Earth

Orbital period of 11 hr 55 min

Five to eight satellites visible from any point on Earth

Block I Satellite Vehicle

Page 8: GPS introduction

The GPS ConstellationSpace segment

Page 9: GPS introduction

GPS Satellite Vehicle Four atomic clocks Three nickel-cadmium

batteries Two solar panels

Battery charging Power generation 1136 watts

S band antenna—satellite control

12 element L band antenna—user communication

Block IIF satellite vehicle (fourth generation)

Space segment

Page 10: GPS introduction

GPS Satellite Vehicle Weight

2370 pounds Height

16.25 feet Width

38.025 feet including wing span

Design life—10 yearsBlock IIR satellite vehicle assembly at Lockheed Martin, Valley Forge, PA

Space segment

Page 11: GPS introduction

Components of the SystemUser segment GPS antennas & receiver/processors Position Velocity Precise timing Used by

Aircraft Ground vehicles Ships Individuals

Page 12: GPS introduction

Components of the SystemUser segment

Page 13: GPS introduction

How does GPS work?

Pseudo-Random Code Complex signal Unique to each

satellite All satellites use

same frequency “Amplified” by

information theory Economical

http://www.lucent.com/minds/infotheory/what.html
Page 14: GPS introduction

Handheld GPS Receivers Garmin eTrex

~$100 Garmin-12

~$150 Casio GPS

wristwatch ~$300

The GPS Store

http://www.thegpsstore.com/site/
Page 15: GPS introduction

GPS Operation Jargon “Waypoint” or “Landmark” “Track” or “Heading” (Heading is

the direction in which you are currently moving)

“Bearing” CDI(The Course Deviation Indicator, CDI, is key

to maintaining your position as you traverse from

one waypoint to another in water or air) Route Mark GOTO

GPS/Digital Telephone

Page 16: GPS introduction

GPS Operation Jargon“Waypoint”

Page 17: GPS introduction

GPS Operation JargonRoute

Page 18: GPS introduction

Components of the System

Ground control segmentMaster control station

Schreiver AFB, ColoradoFive monitor stationsThree ground antennasBackup control system

Page 19: GPS introduction

GPS Ground Control StationsGround control segment

Page 20: GPS introduction

GPS Ground Control StationsGround control segment

Page 21: GPS introduction

How does GPS work?

Satellite rangingSatellite locationsSatellite to user distanceNeed four satellites to determine position

Distance measurementRadio signal traveling at speed of lightMeasure time from satellite to user

Low-tech simulation

Page 22: GPS introduction

How does GPS work? Distance to a satellite is determined by measuring how

long a radio signal takes to reach us from that satellite. To make the measurement we assume that both the

satellite and our receiver are generating the same pseudo-random codes at exactly the same time.

By comparing how late the satellite's pseudo-random code appears compared to our receiver's code, we determine how long it took to reach us.

Multiply that travel time by the speed of light and you've got distance.

High-tech simulation

Page 23: GPS introduction

How does GPS work?Accurate timing is the key to measuring

distance to satellites.Satellites are accurate because they have

four atomic clocks ($100,000 each) on board.

Receiver clocks don't have to be too accurate because an extra satellite range measurement can remove errors.

Page 24: GPS introduction

How does GPS work? To use the satellites as references for range

measurements we need to know exactly where they are. GPS satellites are so high up their orbits are very

predictable. All GPS receivers have an almanac programmed into

their computers that tells them where in the sky each satellite is, moment by moment.

Minor variations in their orbits are measured by the Department of Defense.

The error information is sent to the satellites, to be transmitted along with the timing signals.

Page 25: GPS introduction

GPS Position Determination

Page 26: GPS introduction

System Performance Standard Positioning

System 100 meters horizontal accuracy 156 meters vertical accuracy Designed for civilian use No user fee or restrictions

Precise Positioning System 22 meters horizontal accuracy 27.7 meters vertical accuracy Designed for military use

Page 27: GPS introduction

System Performance

Selective availability Intentional degradation of signal Controls availability of system’s full capabilities Set to zero May 2000 Reasons

Enhanced 911 service Car navigation Adoption of GPS time standard Recreation

Page 28: GPS introduction

System PerformanceThe earth's ionosphere and atmosphere

cause delays in the GPS signal that translate into position errors.

Some errors can be factored out using mathematics and modeling.

The configuration of the satellites in the sky can magnify other errors.

Differential GPS can reduce errors.

http://www.trimble.com/gps/dgps.html
Page 29: GPS introduction

System Performance

Page 30: GPS introduction

Application of GPS TechnologyLocation - determining a basic positionNavigation - getting from one location to

another Tracking - monitoring the movement of

people and things Mapping - creating maps of the world Timing - bringing precise timing to the

world

Page 31: GPS introduction

Application of GPS Technology Private and recreation

Traveling by car Hiking, climbing, biking Vehicle control

Mapping, survey, geology English Channel Tunnel Agriculture Aviation

General and commercial Spacecraft

Maritime

http://www.campsilos.org/mod4/students/farmtreka.shtml
Page 32: GPS introduction

Positioning

Page 33: GPS introduction

Dam /Hydro Power Monitoring

Page 34: GPS introduction

Victoria Dam Monitoring

Beacon 8

Beacon 5

Page 35: GPS introduction

Vehicle Monitoring System

Page 36: GPS introduction

Eagles Eye

Page 37: GPS introduction
Page 38: GPS introduction

Surveying

Page 39: GPS introduction

Precise Positioning

Page 40: GPS introduction
Page 41: GPS introduction
Page 42: GPS introduction

GPS Navigation

Page 43: GPS introduction

Tracking

Page 44: GPS introduction

Tracking

Page 45: GPS introduction

Tracking

Page 46: GPS introduction

Environmental Monitoring

Page 47: GPS introduction

Global Navigation Satellite Systems (GNSS)

Page 48: GPS introduction

Global Navigation Satellite Systems (GNSS)

Page 49: GPS introduction

GPS Newshttp://www.gpseducationresource.com/gps

news.htmOne–page reading exercise

Center of page—main topicFour corners—questions & answers from

readingFour sides—specific facts from readingSpaces between—supporting ideas,

diagrams, definitionsArticle citation on back of page

http://www.gpseducationresource.com/gpsnews.htm
http://www.gpseducationresource.com/gpsnews.htm
Page 50: GPS introduction

Military Uses for the GPS

Operation Desert Storm Featureless terrain Initial purchase of 1000 portable commercial

receivers More than 9000 receivers in use by end of the

conflict Foot soldiers Vehicles Aircraft Marine vessels

Page 51: GPS introduction

GPS for Gunners

Page 52: GPS introduction

On Target

Page 53: GPS introduction

Attached to

Page 54: GPS introduction

GPS Guided Artillery Shell

Page 55: GPS introduction

JDAM

Page 56: GPS introduction

Precision Guided Air Dropthe Marine Corps has been utilizing a different style of parachute than the traditional round system used to airdrop heavy packages. This new parachute system, the Sherpa, has the ability to guide itself to the drop zone from up to 25,000 feet in the air and 15 miles away, landing within 100 yards of the targeted point of impact while carrying up to 2,200 pounds of supplies.

Page 57: GPS introduction

Equipped with a 1,200-square-foot canopy, the Sherpa is programmed with the information of where it needs to go, as well as how long after it falls from the aircraft before it opens the parachute. After it is programmed, the GPS-guided parachute attached to its cargo is loaded aboard an aircraft, flown close to the drop zone and tossed from the plane to make the rest of the way on its own.The main canopy steering lines are connected to the control lines in the airborne guidance unit, which operates with two servo motors.The motors turn to 'reel in' the control lines, allowing for the parachute to turn. The turns are determined by the mission that is programmed into it and based on winds and the target point. The GPS allows for the system to know where it is in the sky and then determine how it needs to get to where it is going."

Page 58: GPS introduction
Page 59: GPS introduction

GPS Guided Mobility

Page 60: GPS introduction

GPS Guided Mobility

Page 61: GPS introduction

Geocaching Cache(Cell) of goodies

established by individuals Coordinates published on

Web Find cache

Leave a message Leave some treasure(Ex Gem) Take some treasure

http://www.geocaching.com/

http://www.geocaching.com/
Page 62: GPS introduction

GPS WebsitesUSNO NAVSTAR Homepage

Info on the GPS constellation How Stuff Works GPS

Good everyday language explanationTrimble GPS tutorial

Flash animationsGPS Waypoint registry

Database of coordinates

http://tycho.usno.navy.mil/gps.html
http://www.howstuffworks.com/gps.htm
http://www.trimble.com/gps/
http://www.waypoint.org/default.html
Page 63: GPS introduction

Classroom Applications Physics

Distance, velocity, time Orbital concepts

Earth Science Mapping Spacecraft

Environmental Science Migratory patterns Population distributions GLOBE Program

Mathematics Geography Technology

http://www.globe.gov/fsl/welcome.html
http://curry.edschool.virginia.edu/teacherlink/content/math/activities/gps-area/home.html
http://www.confluence.org/index.php
Page 64: GPS introduction

Classroom Applications

Careers Aerospace

Satellite vehicles Launch vehicles

Hardware engineering Ground control systems User systems

Software engineering Research careers

Page 65: GPS introduction

Thanks for your interest in the Global Positioning System


Introduction to GPS, Part 2

Introduction to GIS/GPS

Unit 4: GPS introduction

An Introduction to GPS

Introduction Gps

GPS/GSM TRACKER Introduction - GPS designer International CORP

Introduction to NAVSTAR GPS Introduction to NAVSTAR GPS

Mio PND GPS Introduction

Gps Drive introduction

An Introduction to GPS - Virginia Tech · An Introduction to GPS Outline • Why GPS? • What is GPS? • How GPS Works. • What you need to know about GPS. • What can you do

Gps Introduction

Introduction to GPS presentation

Introduction to SIemon GPS

PRESENTATION BASED ON GPS. Introduction To GPS Introduction To GPS

GPS/GSM TRACKER Introduction - Secugissecugis.net/products/call/Tracking_system_solutions_2.pdf · Introduction GPS Designer Intl. CORP. . Application GPS Phone With Personal Locator

GPS, An Introduction

Introduction to gps and gnss

GPS 101: An Introduction to Effective Use of Your GPS 1 ... · GPS 101: An Introduction to Effective Use of Your GPS Page 1 GPS 101: An Introduction to Effective Use of Your GPS These

INTRODUCTION TO GPS:

Leica - Introduction to GPS

Assisted GPS (A-GPS) Application Note · A brief GPS Introduction A brief GPS Introduction The description of the GPS system is beyond the scope of this document. The reader that

04 Introduction to GPS

Project GPS: An Introduction

Oner GPS Introduction

Introduction to GIS and GPS - ACES.edu · Outline • Introduction to GPS • Introduction to GIS • Introduction to the Garmin GPSMAP 60CSx • Low-Cost GPS units • Free and low-cost

Introduction of GPS & AutoCAD Software

Assisted GPS (A-GPS) Application Note - Telit€¦ · Assisted GPS (A-GPS) Application Note ... A brief GPS Introduction A brief GPS Introduction The description of the GPS system

Introduction To Localization Techniques (GPS)

Documento - Desconocido - Introduction to GPS

L4b-GPS - Introduction Notes

Introduction to navstar gps

Oneralarm GPS Introduction

Introduction to gps [compatibility mode]

Introduction To GPS

Introduction -GPS PIPELINE CURRENT MAPPER