K-12 Education: Integrating GIS and GPS
April 1, 2008
Global Positioning Systems
• GPS is a revolutionary navigation systemo 24 satellites orbiting the
eartho Provide location within
metres or less anywhere on the globe.
o Now available in many cars as an option
o Created and operated by the US Department of Defense
More about GPS satellites
• Constellation of 27 satelliteso (24 active + 3 spare)
• Orbit 12,600 miles above eartho (10,900 nautical miles)
• Satellites in 12 hour orbit• First satellite launched in 1978, 24th became
operational in 1994• Selective availability was removed in May,
2000o Handheld receivers are now much more accurate
How does GPS work?
• Measuring distance by measuring time• Satellites send coded signals indicating their
position in space and the exact time the signals are being sent
• Receivers use the time it takes signal to travel from satellite to receiver to determine distance from satellite to receiver
• Information from multiple satellites is used to determine position through ‘triangulation’
How does GPS work?
More about GPS receivers
• A GPS receiver's job is to locate four or more satellites, figure out the distance to each, and use this information to deduce its own location. o Hand-held receivers for recreational
use with accuracy of 10-15 metreso Vehicle mounted receivers for
navigation or agricultural use with accuracy of < 1 metre
o Backpack or tripod mounted receivers for surveying use with accuracy of 5 – 10 centimetres
More about GPS receivers
• Receivers require clear line-of-sight; thus, they will not work indoors or where tall objects obscure the sky
What’s so cool about GPS?
• GPS unitso Can be used as a digital compasso Can be used to determine ground speedo Can store landmarks (locations)o Can be used for dynamic routingo Can be used for mapping applications
Applications of GPS
• In-vehicle Navigation (car, boat, airplane)• Asset Management• Construction• Geologic Research & Mining• Military Navigation and Operations• Mapping & Surveying• Precision Agriculture• Public Health • Public Safety• Wireless Communications
GPS in the classroom
Integrating GIS and GPS
• Collect a series of latitude and longitude points using GPS receiverso add them into an existing digital map
• Skills in o data collection/creationo GPS readingo observation
• Digital photos
Geocaching
• A great way to introduce students to GPSo Teach latitude/longitudeo Take advantage of the wonderful features and
capability of your GPS unit• An entertaining adventure for GPS users
o Individuals and organizations all over the world have set up caches and shared the locations of these caches on the Internet
o Participate in a cache hunt to find an existing cache or create your own
• www.geocaching.com
Classroom projects
• There are many ways you can incorporate GPS data collection into your classroom
• Possibilities includeo a virtual trail in your areao mapping the locations of litter and garbage cans to
determine if there is a relationship, and if more garbage cans are necessary
o collecting data about tree types and locations on school grounds and beyond
o gathering water samples from a local stream and taking GPS readings at each location
o orienteering/navigating (hiking, boating, biking, driving)
Getting started
• GPS units - Garmin eTrexo perfect for introducing students to field
data collection and the power of GPSo industry's smallest and lightest
handheld GPS receivero sleek waterproof housing will fit in your
shirt pocket and weighs only 5.3 ounces
o a 12 channel parallel receiver, differential ready, with a built-in patch antenna
o runs for 22 hours on just two AA batteries
• Pencil, clipboard, paper
Getting started - additions
• Connection cables for your GPS unitso Allow you to download data from your GPS unit to
your computero Free extension available to convert to shapefile
• Local datao Create a base map for viewing the data you have
collectedo Provides context and other features for GIS
analysis with ArcView• Digital camera
Collecting data
• Collect data in the field using GPSo Write down point coordinates and additional
data observations - OR - o Use tracking function of your unit to store
points, lines, or polygons, and write down additional observations
Using the data you collect
• Manually enter the coordinates and observations into a table (Excel, etc.)o Save as a .dbf fileo Add to ArcViewo Use “Add X,Y” or “Add Event Theme” to
create points on your map - OR -
• Use your GPS unit cable to download the data from the unit to your computer
For more information…
• Books from ESRI Presso Integrating GIS and the Global Positioning
System Karen Steede-Terry
o Fun with GPS Donald Cooke
o Community Geography: GIS in Action Kim Zanelli English and Laura S. Feaster
For more information…
• Lessons on the ESRI Canada websiteo http://k12.esricanada.como Integrating GIS and GPS (ArcView 3.x)o Exploring Pukaskwa National Park (ArcView
8.x/9.x)• Garmin website
o http://www.garmin.com/• Trimble GPS
o www.trimble.com/gps• How stuff works
o www.howstuffworks.com