pros and cons of the global positioning system

8/2/2019 Pros and Cons of the Global Positioning System

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Pros and Cons of the GlobalPositioning System for O&M:

10 years Later

Research, Products and Usage for the

Blind and Visually Impaired.


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L. Jeffrey Fitterman, Ed.S., ATP

AT ConsultantFlorida Instructional Materials Center f/t Visually Impaired

4210 West Bay Villa Avenue, Room 26

Tampa, Florida 33611-1206

813-837-7830 voice813-837-7979 fax

http://www.fimcvi.org

[email protected]

Micro-Enabling Resources, Inc. (MERI)

13176 North Dale Mabry Highway

Suite 135Tampa, Florida 33618-2406

813-244-7499 or 3198 voice

[email protected]
http://www.fimcvi.org/mailto:[email protected]:[email protected]:[email protected]:[email protected]://www.fimcvi.org/


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Purpose

In an effort to improve the orientation and mobility

skills of the Blind and Visually Impaired (after 10

years of using Global Position Systems), I am

revisiting the journey to bring educators research onthe selection, acquisition, implementation, and use of

GPS technological developments.


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Presentation

This presentation is not meant to be an in-depth

explanation of GPS research, products and usage, but

a means ofdisseminating thought provoking

information on a topic of importance to thoseindividuals that experience orientation and mobility

challenges in their daily lives.

L. Jeffrey Fitterman, Ed.S., ATP


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Overview

History of the Global Positioning System (GPS) How GPS works

Types of GPS receivers

Applications and Uses of GPS

Implications for O&M usage

Past research and development

Off-the-shelf product usage

Overall advantages and disadvantages

Applied Research

Educational activities using GPS technology Conclusion

Where do we go from here?


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What is GPS?

Electronic navigational system based on the use ofhigh orbiting satellites to find your relative

position on the Earths land, water or sky.


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History

Satellite-Based Systems

1957 Sputnik

Measuring Doppler Shift in the frequency of satellites bleep, bleep

1960s SatNav Navy Navigation Satellite System

Measuring the Doppler Shift in the frequency of satellites radio wave of

four to five satellites nested. Intermittent coverage

1970 Radio Determination Satellite Systems (RDSS) Loran-C: continuous position-fixing but lacked worldwide coverage


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History

Satellite-Based Systems

1973 Navigational Satellite Timing And Ranging Global

Positioning System (NavStart GPS)

Consists of 24 satellites in six orbital planes

98% probability of having 21 or more satellites operational at one time Continuous position fixing with a minimum of 5 satellites in view to users

world wide


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How GPS Works

System Characteristics Control Segment

Provides and updates the information on satellite position that

is transmitted as part of the satellites message

Space Segment

Consists of a constellation of 24 satellites positioned in six

synchronic orbital planes

User Segment

Consists of all areas in which GPS signals are used to

determine navigation and time information


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How GPS Works

Control Segment

Space Segment

User Segment


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How GPS Works

GPS determines the range at a specific time bymeasuring how long it takes a radio signal to reach a

receiver from the satellite

Signal transfer time is achieved by synchronizing the satellites and

GPS receivers.

By measuring the time difference in receiving the satellites code,

distance from the satellite can be computed to establish Line Of

Position (LOP)


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How GPS Works

Line of Position (LOP)


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How GPS Works

To get a two dimensional fix, anotherLOP is calculated

from a second satellite

Where the LOPs cross is your relative position

To resolve the time element A third satellite is needed to determine a two dimensional fix

A fourth satellite is necessary for a three dimensional fix


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How GPS Works

Finding the LOP of 3 separate satellites will give you a

2 dimensional look at your position.

LOP1

LOP2

LOP3

1. Satellites are at an altitude of 20,180 km.

2. Satellite orbits are 60 degrees between each of 6 orbital plane.

3. At least 5 satellites visible to user at any given time.


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GPS Accuracy

The GPS system

has been turned over to the Public Domain and all military

cryptology has been removed to allow a Precise Positioning

System (PPS). Positioning now gives us a range with a decrease margin of error

from 100 meters to 0-3 meters.


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GPS Accuracy

Errors in accuracy Control Segment produced

Less expensive clock in receiver

Atmospheric conditions

Physical Obstructions


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GPS Accuracy

WAAS-Wide Area Augmentation System a system of satellites and ground stations that provide GPS signal

corrections, giving position accuracy up to five times better. A

WAAS-capable receiver can give you a position accuracy of better

than three meters, 95 percent of the time. You don't have to

purchase additional receiving equipment or pay service fees to useWAAS.


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GPS Accuracy

How WAAS Works

Ground reference stations monitor GPS satellite data, and master

stations collect data from the reference stations and create a GPS

correction message accounting for GPS satellite orbit and clock

drift plus signal delays caused by the atmosphere. The corrected

differential message is then broadcast through geo-stationarysatellites (satellites with a fixed position over the equator). Any

WAAS-enabled GPS receiver can read the signal.


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GPS Receivers Functions

Receivers

Acquire or lock onto the satellites

Make measurements or determine how far away the

satellite is from the receiver Read the satellites navigational message


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Types of GPS Receivers

Sequential (Slow LockIncreased Error)

Acquire and move through a set of satellites with a

single channel to solve for position.

Simultaneous/Parallel (12 channels)

Acquire and solve each individual satellites data using

parallel channels, each of which is dedicated to a single

satellite.


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Sequential Receivers (most are obsolete)

Starved power single channel

Single channel slow sequence

Two channel slow sequence Single channel fast sequence


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Multiple/Parallel Receivers

Independent Channels (4 to 12)

Instantaneous position

Constant velocity data

High accuracy

Require less signal strength

Betterperformance to acquire satellites and begin

navigation (Time to First Fix - TTFF)


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General Applications

and Uses of GPS

Everyday Uses can be water, land, or air

Position Functions (Where are you?)

Dead Reckoning Functions (Where do we want to go?)

Steering Functions (How do we get there?)


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and Uses of GPS

Dead Reckoning Functions (Where do we want to go?)

Course over ground

Speed over ground

Distance traveled

Distance to waypoint

Elapsed time

Estimated time of arrival Sensory and Physical Landmarks


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and Uses of GPS

Steering Functions (How do we get there? )

Course to steer

Course corrections

Graphical displays


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Land Applications and

Uses of GPS

Pedestrian navigation

Vehicularnavigation


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Uses of GPS

Pedestrian navigation

From point to point

Hiking

Walking

Locating current point

Point on city mapWaypoint


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Uses of GPS

Vehicular navigation

From point to point

Bicycling and skatingAutomobile

Sailing and boating

Locating current point

Point on city map

Waypoint

R h


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Research

Implications for O&M Usage

MoBic

Drishti

Brunel Navigation System for the Blind

NOPPA

BrailleNote GPS

Trekker Trinetra
http://en.wikipedia.org/wiki/GPS_for_the_visually_impairedhttp://en.wikipedia.org/wiki/GPS_for_the_visually_impairedhttp://en.wikipedia.org/wiki/GPS_for_the_visually_impairedhttp://en.wikipedia.org/wiki/GPS_for_the_visually_impaired


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Research

Implications for O&M UsageMoBIC

MoBIC meansMobility of Blind and Elderly people Interacting withComputers, which was carried out from 1994 to 1996 supported by theCommission of the European Union. It was developing a route planningsystem which is designed to allow a blind person access to informationfrom many sources such as bus and train timetables as well as electronicmaps of the locality. The planning system helps blind people to study andplan their routes in advance, indoors.

With the addition of devices to give the precise current position andorientation of the blind pedestrian, the system could then be used outdoors.

The outdoor positioning system is based on signals and satellites whichgive the longitude and latitude to within a meter; the computer converts thisdata to a position on an electronic map of locality. The output from thesystem is in the form of spoken messages. Add additional GPS/DGPScapabilities for current position and orientation of pedestrians.
http://en.wikipedia.org/wiki/Mobilityhttp://en.wikipedia.org/wiki/1994http://en.wikipedia.org/wiki/1996http://en.wikipedia.org/wiki/European_Commissionhttp://en.wikipedia.org/wiki/Signal_%28information_theory%29http://en.wikipedia.org/wiki/Satellitehttp://en.wikipedia.org/wiki/Longitudehttp://en.wikipedia.org/wiki/Latitudehttp://en.wikipedia.org/wiki/Latitudehttp://en.wikipedia.org/wiki/Longitudehttp://en.wikipedia.org/wiki/Satellitehttp://en.wikipedia.org/wiki/Signal_%28information_theory%29http://en.wikipedia.org/wiki/European_Commissionhttp://en.wikipedia.org/wiki/1996http://en.wikipedia.org/wiki/1994http://en.wikipedia.org/wiki/Mobility


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Research

Implications for O&M UsageDrishti

is a wireless pedestrian navigation system. It integrates several technologiesincluding wearable computers, voice recognition and synthesis, wirelessnetworks, Geographic information system (GIS) and GPS. It augments

contextual information to the visually impaired and computed optimizedroutes based on user preference, temporal constraints (e.g. traffic congestion),and dynamic obstacles (e.g. ongoing ground work, road blockade for specialevents).

constantly guides the blind user to navigate based on static and dynamic data.

Environmental conditions and landmark information queries from a spatialdatabase along their route are provided on the fly through detailedexplanatory voice cues. The system also provides capability for the user toadd intelligence, as perceived by the blind user, to the central server hostingthe spatialdatabase.
http://en.wikipedia.org/wiki/Geographic_information_systemhttp://en.wikipedia.org/wiki/Spatialhttp://en.wikipedia.org/wiki/Databasehttp://en.wikipedia.org/wiki/Databasehttp://en.wikipedia.org/wiki/Spatialhttp://en.wikipedia.org/wiki/Geographic_information_system


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Research


Brunel navigation system for the blind Prof. W. Balachandran is the pioneer and the head of GPS research group at

Brunel University. He and his research team are pursuing research onnavigation system for blind and visually impaired people. The system is

based on the integration of state of the art current technologies, includinghigh-accuracy GPS positioning, GIS, electronic compass and wirelessdigital video transmission (remote vision) facility with an accuracy of3~4m. It provides an automated guidance using the information from dailyupdated digital map datasets e.g. roadworks. If required the remoteguidance of visually impaired pedestrians by a sighted human guide using

the information from the digital map and from the remote video imageprovides flexibility.

The difficulties encountered includes the availability of up to dateinformation and what information to offer including the navigationprotocol.Levels of functionality have been created to tailorthe information to theusers requirements.
http://en.wikipedia.org/wiki/Brunel_Universityhttp://en.wikipedia.org/wiki/Navigationhttp://en.wikipedia.org/wiki/Wirelesshttp://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Transmission_%28telecommunications%29http://en.wikipedia.org/wiki/Informationhttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/Tailorhttp://en.wikipedia.org/wiki/Tailorhttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/Informationhttp://en.wikipedia.org/wiki/Transmission_%28telecommunications%29http://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Wirelesshttp://en.wikipedia.org/wiki/Navigationhttp://en.wikipedia.org/wiki/Brunel_University


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Research


NOPPA navigation and guidance system was designed to offer public transport

passenger and route information using GPS technology for the visuallyimpaired. This was a three-year (2002~2004) project in VTT IndustrialSystems in Finland. The system provides an unbroken trip chain for a

pedestrian using buses, commuter trains and trams in three neighbor citiesarea. It is based on an information server concept, which has user-centeredand task oriented approach for solving information needs of special needsgroups.

information Serveris an interpreterbetween the user and Internet informationsystems. It collects, filters and integrates information from different sources

and delivers results to the user. The server handles speech recognition andfunctions requiring either heavy calculations or data transfer. The datatransfer between the server and the client is minimized. The user terminalholds speech synthesis and most of route guidance.

currently able to offer basic route planning and navigation services inFinland. In practice, the limits are map data can have outdated information orinaccuracies, positioning can be unavailable or inaccurate, or wireless datatransmission is not always available.
http://en.wikipedia.org/wiki/Transporthttp://en.wikipedia.org/wiki/Server_%28computing%29http://en.wikipedia.org/wiki/Interpreter_%28computing%29http://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Calculationshttp://en.wikipedia.org/wiki/Synthesishttp://en.wikipedia.org/wiki/Synthesishttp://en.wikipedia.org/wiki/Calculationshttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Interpreter_%28computing%29http://en.wikipedia.org/wiki/Server_%28computing%29http://en.wikipedia.org/wiki/Transport


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Research


BrailleNote GP device is developed by Sendero Group, LLC, and Pulse Data International,

now called Humanware, in 2002. It is like a combination of a personal

digital assistant, Map-quest software and a mechanical voice.

With a receiver about the size of a small cell phone, the BrailleNote GPSutilizes the GPS network to pinpoint a travelers position on earth and nearby

points of interest. The personal computers receive radio signals from

satellites to chart the location of users and direct them to their destination

with recorded voice commands. The system uses satellites to triangulate the

carriers position, much like a ship finding its location at sea.

Visually impaired people can encode points of interest such as local

restaurants or any other location, into the computers database. Afterward,

they can punch keys on the units keyboard to direct themselves to a specific

point of interest.
http://en.wikipedia.org/wiki/Devicehttp://en.wikipedia.org/wiki/Encodehttp://en.wikipedia.org/wiki/Encodehttp://en.wikipedia.org/wiki/Device


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Research


Victor Trekker designed and manufactured by Canada-based company VisuAid, was

launched on March 2003. It is a personal digital assistant (PDA)

application operating on a Pocket PC, adapted for the blind and visually

impaired with talking menus, talking maps and GPS information. Fullyportable (weight 600g), it offered features enabling a blind person to

determine position, create routes and receive information on navigating

to a destination. It also provided search functions for an exhaustive

database of point of interests, such as restaurants, hotels, etc.

It is fully upgradeable, so it can expand to accommodate new hardware

platforms and more detailed geographic information.

Trekker and Maestro, which is the first off-the-shelf accessible PDA

based on Windows Mobile Pocket PC, are integrated and available in

May 2005.
http://en.wikipedia.org/wiki/Personal_digital_assistanthttp://en.wikipedia.org/wiki/Pocket_PChttp://en.wikipedia.org/wiki/Portablehttp://en.wikipedia.org/wiki/Databasehttp://en.wikipedia.org/wiki/Hardwarehttp://en.wikipedia.org/wiki/Platform_%28computing%29http://en.wikipedia.org/wiki/Personal_digital_assistanthttp://en.wikipedia.org/wiki/Personal_digital_assistanthttp://en.wikipedia.org/wiki/Platform_%28computing%29http://en.wikipedia.org/wiki/Hardwarehttp://en.wikipedia.org/wiki/Databasehttp://en.wikipedia.org/wiki/Portablehttp://en.wikipedia.org/wiki/Pocket_PChttp://en.wikipedia.org/wiki/Personal_digital_assistant


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Research


Trinetra The project aims to develop cost-effective, independence-enhancing technologies to

benefit blind people. One such system addresses accessibility concerns of blind

people using public transportation systems. Using GPS receivers and staggered

Infrared sensors, information is relayed to a centralized fleet management server via

a cellular modem. Blind people, using common text-to-speech enabled cell phones

can query estimated time of arrival, locality, and current bus capacity using a web

browser.

Trinetra, spearheaded by Professor Priya Narasimhan, is an ongoing project at the

Electrical and Computer Engineering department ofCarnegie Mellon University.Additional research topics include item-level UPC and RFID identification while

grocery shopping and indoor navigation in retail settings. Additional information

can be found here: http://www.ece.cmu.edu/~trinetra/
http://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Web_browserhttp://en.wikipedia.org/wiki/Web_browserhttp://en.wikipedia.org/wiki/Carnegie_Mellon_Universityhttp://en.wikipedia.org/wiki/Universal_Product_Codehttp://en.wikipedia.org/wiki/RFIDhttp://www.ece.cmu.edu/~trinetra/http://www.ece.cmu.edu/~trinetra/http://www.ece.cmu.edu/~trinetra/http://www.ece.cmu.edu/~trinetra/http://en.wikipedia.org/wiki/RFIDhttp://en.wikipedia.org/wiki/Universal_Product_Codehttp://en.wikipedia.org/wiki/Carnegie_Mellon_Universityhttp://en.wikipedia.org/wiki/Web_browserhttp://en.wikipedia.org/wiki/Web_browserhttp://en.wikipedia.org/wiki/Infrared


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Research


GPS researchResearch considerations for the User

Travel planning and orientation during travel.

Need more detailed information before travel.

Have to rely on less perceptual information from the

environment during travel.

More information on useful landmarks (dead-reckoning).

Information on head height obstacles.

Suitable places to cross streets.

Headphones may block environmental sounds.

Device should be inconspicuous.

R h


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Research


GPS research Research considerations for the O&M Specialist

Increase independence and quality of life.

Increase independence through sensory, navigational, and

mobility skills.

Should be easy to integrate into existing training programs.

Should be used as an enhancement to training.

O&M specialists need adequate training in the implementationand integration of GPS devices before they were expected to

teach users.


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Advantages of GPS Navigation

Assistive Technology enhancement for orientation &mobility

Source of real-time information for navigation

User can manipulate navigational information Navigational information is sequential

Add individual routes and dead reckoning information

Can be used overseas in other countries


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Disadvantages of GPS Navigation

Variable accuracy

Obstructed reception

Physically conspicuous

Auditory discrimination

Cost and maintenance

Power supply issues


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Off-the-Shelf Hardware

Factory Adapted for the Blind

User Adapted f/t Blind


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Off-the-Shelf Software

PacMate StreetTalk GPS

calculate the distance and directions to an address/intersectionfind out the relative location of hundreds of Points of Interest

create routes for either walking or riding in a vehicle

information on speed, direction, and your altitude

Braille Note GPS

Maestro

Blue Tooth GPS Receivers


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Not Adapted f/t Blind

RouteBuddy

The Premium Mac OSX GPS mapping software title that all Mac GPS Users have

been waiting for... USA or North America

iGuidance

navigation software for Windows & Pocket PC. USA & CANADA (DVD)with

WM5 Support!

Streets & Trips

includes Pocket Streets for your Pocket PC and SmartPhones - WM5 Support!


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Street Atlas

Adds 150 million phone & address listings linked to the maps. Import and

geo-locate your own data. PLUS all the features of Street Atlas USA

Fugawi

atlas of the continental USA for the home computer with included software

for GPS and PDA

Not Adapted f/t Blind


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Where Do We Go From Here?

GPS devices will become:

more accurate

quickerTTFF

betterresolution and larger displays

Better quality voices on smaller units

less costly

more compact

longer and more reliable battery life

R i d A li i


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Review and Applications

Our Turn.

Who will benefit from this technology?

What type of technology should I consider?

Where do I go to obtain assistance regarding thistechnology?

When should this technology be used?

Why should this technology be considered?

How will you use this new technology?

O& G S


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O&M GPS Research

Accessible GPS: Reorientation and Target Location Among Users with Visual

ImpairmentsJournal of Visual Impaired and Blind, 2006.Abstract: This article presents the results of two single-subject experiments that were

designed to determine consumers' ability to use a BrailleNote GPS. The participantsdecreased their mean orientation time from 6 minutes to 45 seconds and increasedtheir target- location efficiency fourfold with BGPS than without BGPS. Additionalresults and implications for the field are presented.

Braillenote GPS: Making the World Accessible for the Blind and Visually ImpairedTraveler

Melanie White, COMS,

Global Positioning Satellite technology is having a very positive benefit for many visually

impaired travelers. In this session participants will learn the sequence of skills for the GPS

and have a chance to see videos of these skills in use. They will also receive resources for

lessoning planning. http://www.tsbvi.edu/Outreach/handouts/jun07/index.htm

O&M GPS R h
http://www.tsbvi.edu/Outreach/handouts/jun07/index.htmhttp://www.tsbvi.edu/Outreach/handouts/jun07/index.htm


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O&M GPS Research

Florida State University/College of Education: Mapping the Campus for StudentsWho are Blind

Abstract: The outcome of the project is to map the FSU campus with Points of Interest that

Would allow a blind student to navigate the campus with no or very little assistance.

Bruce Alsup from OSET will serve as the overall project manager. This project envisions the FSU

summer intern graduate students using equipment provided by VisuAide and Freedom Scientific.

The student teachers will first map the FSU campus and then work with newly arrivingUndergraduate students as part of their campus Orientation and Mobility (O&M) training. Training

for the student teachers will be provided by a team from OSET, FS, and VisuAide: Bruce Alsup,

Jeff Bazer, and Louis Duchene respectively. Training will be provided to undergraduate students by

the student teacher interns and OSET. FSU Department of Education will provide an on-site project

supervisor, presumably Kathryn O'Farrell.

Timeline: Preparation and intern training, April-May 15 2004; Customize mapping of FSU campus,

May-June 2004; and Undergraduate student O&M, June-July 2004

Desired Outcomes: Accessibility for O&M on the FSU Campus will be dramatically increased.

Newly arriving undergraduate students will be able to navigate the FSU campus independently.

Graduate student interns will gain invaluable experience and training for using technology devises

coupled with O&M techniques.

O&M GPS A i i i
http://www.oset.com/poi_management.htmhttp://www.oset.com/poi_management.htm


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O&M GPS Activities

Street Orientation/Verification (POI)

Setting Point of Interests

Restaurants, meeting location, schools, street intersection, etc.

Planned Trip POI

Highway intersections, hotels, restaurants, origin/destination

Pedestrian and Public Transportation Verification(POI)

Bus

stops, transfers, riding time

Taxiverify distance, directions, route, and POI

Special Transport

verify direction, POI, route

O&M GPS A ti iti


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O&M GPS Activities

Educational/Instructional and Supervised Activities - GeoCaching

Traditional Cache

"If you take an item, leave an item, and write in the logbook."

Multi-Cache

A multi-cache ("multiple") involves two or more locations

Letterbox Hybrid

A letterbox is another form of treasure hunting using clues instead of coordinates

Event Cache Litter (trash out), charity walks related to finding multiple cache locations

Mega-Event Cache 500 or more people

Mystery or puzzle caches

involve word puzzles. You first need to solve to determine the coordinates for a locations.

GPS Adventures Maze Exhibit

traveling educational exhibits designed to teach people of all ages about navigation, GPS technology and

geocaching. Virtual Cache

Finding a location from coordinates and sharing information about your visit Outside locations such as Sporting field, gardens, swimming pool, fish pond, etc.

Locationless (Reverse) Cache

A scavenger hunt for a specific object and log the coordinates


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The Rest Is Up To You!

The presentation was not meant to be a

complete compendium of information and

activities. It was meant to be a starting

point for the inclusion of the Global

Positioning System Technology into your

O

rientation andM

obility Program forclients and students.


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GPS Presentation Materials

You may obtain a copy of this presentation

by going to the following link and selecting

GPS Ten Years Later. The presentation willbe in 3 formats (PowerPoint Show, PDF,

and RTF Text) http://www.fimcvi.org/index_files.cfm?category=17
http://www.fimcvi.org/index_files.cfm?category=17http://www.fimcvi.org/index_files.cfm?category=17

pros and cons of the global positioning system

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