Welcome to this month's Technology in PE. In the spirit of spring with warmer weather, we will take a close look at some recent technology that has changed the ways individuals enjoy the outdoors - Global Positioning Systems (GPS). Below are numerous links, articles, and various other resources to help you learn and use GPS.

The first section, which is derived from a presentation by pelinks4u publisher Dr. Stephen Jefferies, serves as an introduction to GPS. This section briefly discusses the history of GPS, how it works, and its purpose.

The next section offers information on GPS equipment for teachers, including comparisons of different models, and links to quick start guides. Read the excerpt from The Complete Idiot's Guide to Geocaching, by Jack Peters, for a quick list of essential GPS unit features to look for when shopping.

The next section contains lesson plan ideas for GPS and physical education. Also included in this section are a number of articles on how GPS and GPS devices are being used for classroom and family fun through Geocaching.

Happy May to everyone. Please feel free to contact me if you have any questions or comments about this section

Leon Letson
Guest Technology Section Editor

What is GPS?

GPS (Global Positioning System) is a satellite-based radio navigation system provided by the US Department of Defense. It permits users with suitable receivers to establish their position, speed, and time on land, sea, or in the air at any time of the day or night and in any weather condition.

The System is accurate to within 30 meters, which is equal to or better than any other radio navigation system available today. GPS receivers can obtain a position fix anywhere in the world, and are now commonly found in everything from car navigation systems to small, handheld navigation systems. This technology became available to the general public in 2000. Prior to then, it was strictly used for military purposes.

Latitude & Longitude - An understanding of latitude and longitude is essential for anyone wishing to make use of GPS technology. Latitude and longitude are the two sets of circles used to divide the earth into sections. There are several methods used to remember the difference between latitude and longitude.

Latitude can be compared to a type of ladder for climbing to the top of the globe because it consists of parallel lines that circle the globe from north to south. Latitude lines run parallel with the equator, which equals 0 degrees longitude. The North Pole is 90 degrees and the South Pole is -90 degrees.

Longitude lines also circle the entire globe, but they pass through the north and south poles. Longitude lines are divided into 360 degrees. Whereas latitude lines are all evenly spaced, longitudinal lines become closer together as they approach the poles of the earth. The prime meridian, which passes through England, is 0 degrees longitude.

Unlike latitude lines, longitude lines increase by degree in either direction from this line. There is no such thing as a negative longitude. Instead, there are 0 to 180 degrees east and 0 to 180 degrees west. Invoking the image of a peeled orange and its slices running north-south is a helpful way to keep your students straight on longitude versus latitude.

The Three Major Segments of a GPS System

The Space Segment consists of a constellation of 24 satellites orbiting the earth at an altitude of 20,000 kms. These satellites act as reference points from which receivers on the ground determine their position. The Control Segment consists of five stations located on earth that track the satellites. The User Segment consists of antennas and receiver-processors, such as the hand-held devices discussed in the GPS Equipment for Teachers segment of this section.

So How Does It Work? - GPS receivers use the principle of "ranging." The receiver measures the distance from a location on earth to the positions of several satellites to determine the latitude and longitude of the position on earth.

Suppose you turn on your GPS receiver and it picks up the signal of one satellite. The receiver tells you the location of that satellite and the distance between you and it. This single measurement is not a big help. At best, you can conclude that you are within a rather large circle whose circumference is determined by your distance from the satellite. You are still lost!

Now suppose that your GPS receiver picks up signals from another satellite. This helps to narrow down your location. You now know that you are somewhere within the intersection of two large circles. You still don't know exactly where you are, but things are starting to look better!

Going one better, your receiver picks up signals from a third satellite, which gives you your position within the intersection of three circles. You have a position but no check on its quality! With four satellites you get a precise point for your position and you also know your elevation. You have a position that is accurate to 30 meters!

Popular Uses of GPS Units

	Find your current location
	Find another location
	Plan (and save) a route to another location
	Find your way back to your starting point
	Find your elevation
	Find your speed of travel
	Estimate your time of arrival at a distant location
	Find the distance you have or will travel
	Time of day, sunrise, sunset
	Find how much time you have been moving or stopped
	Save location of good fishing, camping, hiking spots, etc.

How to Use GPS

This brief tutorial from Trimble Navigation Ltd., provides easy-to-follow instructions for five basic functions of GPS: location, navigation, tracking, mapping, and timing.

continue top of next column

Please be sure to read the introduction to GPS in the first column of this page.

Selecting the right GPS unit can be a daunting task for anyone, but especially someone entirely unfamiliar with this technology. Below are some tips to help you make informed purchase decisions. Brief introductions to some popular models, including their quick start guides, have also been included.

Feature Considerations for Good Geocaching GPS Gear - The Complete Idiot’s Guide to Geocaching, by Jack Peters

Basemap. This is highly recommended. The additional cost is marginal, and the increase in the equipment's usefulness is substantial.

Channels. Use a receiver with 12 parallel channels. This should include most manufactured after 1997. Older, single-channel receivers are much slower and may not be as accurate.

External antenna jack. This allows the equipment to be mounted inside a vehicle. It is not always possible to obtain good satellite coverage through a front windshield. Even backpackers will benefit from the ability to safely store the receiver inside a pack with an antenna attached to backpack shoulder straps.

Interface. If using the receiver with a computer, be sure that it includes both data in/out ports, and make sure it's NMEA compatible.

Memory. This is used to load detailed topographic or street-level digital maps into the receiver. Topo maps use up a great deal of memory. Capacity should be at least eight megabytes, or the receiver should include the ability to accept a memory card for as much memory as needed.

Power source. Use a cigarette lighter power cable whenever possible. If you're only using batteries, make sure to carry spares and use a solar charger for extended field use.

Rocker keypad. Using a receiver without a rocker keypad is like using a computer without a mouse.

Screen size. For visual ease of operation, use a receiver with the largest screen that can be realistically carried. Screen size is measured diagonally. Color is great and helps define map features, although it does burn battery power.

Waterproof. Sooner or later the gear will get submerged. Get gear that is at least water-resistant. Plastic bags and boxes give electronics a little additional protection.

Popular, Easy-to-Use GPS Units

Garmin Forerunner 101 - This GPS unit, which operates on two AAA batteries, offers users an entry-level personal training device with GPS. It measures speed, distance, pace and calories burned. The Forerunner 101 also stores up to two years' worth of lap history in memory. You can retrieve lap data for previous workouts by date, week or month, so you can see how much progress you've made in your training (Quick Start Guide).

Garmin Forerunner 201 - This GPS unit, which operates on a rechargeable lithium-ion batter, allows the user to download workout information to software on a personal computer or via the Internet. Analyze data with interactive graphs that chart your pace, time and distance. Overlay your run on a map so you can pinpoint specific areas and see how elevation and other factors affect your performance. The Forerunner 201 is packed with workout-enhancing features that make your training much easier, such as alarms that sound when you reach a certain distance or time, or when you exceed a certain pace (Quick Start Guide).

Garmin Forerunner 301 - This GPS is similar in options to the Garmin Forerunner 201, but comes with the added feature of a digital, coded heart-rate monitor. This allows the Forerunner 301 to displays your current heart rate zone, a range of heart beats per minute that helps you gauge the intensity of your workout and train more effectively. After a few intense runs, Forerunner's AutoLearn feature calculates your heart rate zones and automatically adjusts them as your fitness level improves (Quick Start Guide).

 Geocaching is a relatively new sport that combines GPS savvy with outdoor fun. Review the GPS in Gym lesson plan for ways to get your students involved with Geocaching. Also included in this section are some articles about physical educators and families that have discovered the fitness potential of GPS.

Geocaching: The Official Global GPS Cache Hunt Site - This is the most widely used Geocache Web site. Here you'll find resources for setting up or participating in Geocache "treasure hunts" in your area. Check out the Forums link for discussions on how educators are integrating GPS and Geocache into their curriculum. Geocache FAQ is a comprehensive resource for learning everything there is to know about Geocache.

Geocachingkids.com - This Web site is designed with children in mind. In simple, easy-to-understand terms, Geocachingkids.coms explains how GPS and Geocaching work. The Geocaching and Education link contains many useful tips on how to turn Geocaching into learning experiences for kids.

Geocaching & Physical Education

Here is a lesson plan idea for integrating GPS technology into your physical education curriculum.

The Utah Education Network (UEN) has gathered a number of assignments pertaining to GPS. Aside from physical education, there are also lesson plans for social studies, math, and science that can be implemented in an interdisciplinary fashion. Below is an example of one of UEN's GPS lesson plans for physical education.

GPS in Gym
After finding the latitude and longitude of your area, set up eight stations with geocaches, or "treasure chests," for the students to find and complete activities. Materials needed include paper, pencils, and 8-10 GPS units. Divide the students into small, even-numbered groups. Once the students have tracked down a station, they must then complete the activity listed in the treasure chest. Once they've completed the activity and recorded it on their activity worksheet, the hunt begins again. The first group to complete all eight activities first and accurately wins.

Geocachers on New Learning Path
Bismarck, ND, teachers are creating a new crop of cachers through physical education and other classes. "It's a great lesson on perseverance," physical education teacher Kurt Weinberg said.

Weinberg takes his students at Pioneer and Highland Acres schools out to Cross Ranch State Park to geocache, the name of the game, to find hidden containers with a global positioning unit and a set of clues. Weinberg likens it to a high-tech Easter egg hunt.

Geocaching: Hunt Your Way to Fitness and Fun
Having trouble tearing your kids away from TV, the internet and electronic games? Follow this mom's lead: use a little technology of your own and the promise of treasure to lure them outside.

"When I heard about geocaching, I knew it was the perfect way to tear my sons away from the computer," says Kim, a mother of two.

Listed below are just a few of the grant opportunities that exist for educators interested in GPS technology. Although federal grant funding is somewhat limited for GPS technology, numerous private corporations, such Best Buy, offer annual funding for schools and educators.

Best Buy Teach Awards: Rewarding schools that use technology

	Over the past four years, more than 4,800 K-12 schools have received over $14 million in Best Buy Teach Awards.
	Awards go to K-12 public, private, and parochial schools using interactive technology in classrooms.
	Schools must be within 50 miles of a Best Buy store to apply.
	Educators must apply online between July 1 and September 30.
	Find out how teachers are using technology to make learning fun.

Geocaching hits the mainstream: GPS gadgets lead users on new adventures - This could be the three-letter answer for that last tough gift problem: GPS - a global positioning system. A high-tech gadget that appeals to the inner nerd, it also prompts the user to get off the couch and into the great outdoors. Read more. Also read "Geocaching: A high-tech treasure hunt for kids of all ages."

GPS Users get an Instant Upgrade

On May 2, 2000, at approximately midnight, eastern savings time, the great blue switch* controlling selective availability was pressed. Twenty-four satellites around the globe processed their new orders, and instantly the accuracy of GPS technology improved tenfold. Tens of thousands of GPS receivers around the world had an instant upgrade.

The announcement a day before came as a welcome surprise to everyone who worked with GPS technology. The government had planned to remove selective availability - but had until 2006 to do so. Now, said the White House, anyone could "precisely pinpoint their location or the location of items (such as game) left behind for later recovery." How right they were.

This is a very interesting article and subject. Read the rest. Also read "Global Positioning System" from Wikipedia.com.

Let's Play a Game of Cache Me if You Can
Last weekend, I used multibillion-dollar government defense satellites to search for Tupperware hidden in the woods. Call it an Easter Egg hunt for geeks. Geocaching (pronounced "geo-cashing" as in cashing a check) is my favorite form of exercise, a different way of sightseeing, and a high-tech hobby all wrapped into one. Read more.

Zeroing in on fun - Who doesn’t like to hunt for treasure? A relatively new activity that encourages people, especially families, to get out and about exploring the region is gaining momentum in the Fraser Valley. Geocaching began to take off in 2000, when selective availability from global positioning satellites (GPS) was removed May 1 of that year. Read more.

Teaching Geography With Geocaching
A GPS device and a hunger for adventure are all you need for high tech treasure hunting. At www.geocaching.com, you will find the latest treasures, or “caches,” in your area, how to hide your own cache, and information on how to get started in this fun and exciting sport.

How do kids start geocaching? You'll need two things to start: an adult and a GPS receiver. You'll also need to know the coordinates for a local geocache. That you will find at geocaching.com. Read on!

GPS ACTIVITIES - Read the fun and educational ways that Tangipahoa Parish School System Teachers use GPS technology. Click the large pictures for presentations of the hunt, and also click the thumbnails. Check it all over thoroughly to help come up with your own ideas.

GPS & GeoCaching - where students are the search engine! Using GPS and Geocaching in the core curriculum has become a powerful tool in enhancing student understanding of geography, scientific inquiry, math concepts, physical education, problem solving, and language arts. Learn more about it in this web site!

Geocaching With Kids: Activate the Learning Environment - Geocaching is a great activity for all ages. Whether parents want to explore nature with their children or teachers want to activate the learning environment with hands-on experiences, there's a geocache adventure that's right for you.

Kids Are Cachers Too - Editor's note: The pairing of caching with educational settings is becoming particularly common, and will be a recurring theme in the Caching Kids section of Todays Cacher. This month's issue tells stories involving caching in the classroom from two very different perspectives.

Garmin has a diverse product line and distributors in virtually every part of the world. They have built and sold millions of GPS receivers.

Map Town Ltd. - Map Town Ltd. is an exclusive retailer of Garmin International Units. Map Town Ltd. features outdoor recreation, marine, nautical, and pocket PC GPS receivers with compatible software and accessories.