14 MONITORING TIMES August 2002

GPS receiver. For the uninitiated, the GPS sys-tem works with a network of 24 satellites orbit-ing some 12,500 miles up in the sky. Each onehas an atomic clock to set the precise timing thatis part of the math used by a land-based a GPSreceiver to triangulate its location on the face ofthe earth. GPS satellites continuously transmitsignals and data. Those signals are picked up byGPS receivers, with up to 12 satellites beingreceived simultaneously.

A calculator in the GPS receiver crunchesthe data, and shows it to us as latitude and lon-gitude. The GPS term for a set of latitude andlongitude coordinates is waypoint. If you con-nect the waypoint dots, you have what’s calleda route. As you move with a GPS in your hand,it generates a virtual breadcrumb trail called atrack. Waypoints, routes and tracks can be savedin a GPS memory. Now you have the basic GPSvocabulary.

There many websites that will tell you howGPS works, like “How Stuff Works,” but thebest site for new GPS users is The GPS Infor-mation Site at http://www.joe.mehaffey.com.The owners, Joe Mehaffey and Jack Yeazel, areham radio operators who provide expert reviewsof GPS products and useful GPS links. Theymake it clear that people who love radios can

have fun with GPS receivers, too.

Got a Map in Your Hand?When people want to know how much to

spend on a GPS receiver, we ask if they want tosee a map in their hand. Entry-level GPS receiv-ers display basic geographic information: lati-tude, longitude, elevation, direction, and bear-ing. They calculate the distance between pointsand estimate your arrival time. They will alsohave a screen that shows a graphic representa-tion of the points you marked with the GPS, asif you had drawn a sketch, but that isn’t a scalemap. For that, you have to spend more, andmost GPS users think it’s worth the expense.

Better quality GPS receivers come with abase map of North America, but with such alarge area to cover, the maps don’t include muchdetail. Spend a little more, and you get mapmemory, up to 24mb, to upload more maps anda higher level of detail: city maps, topographicmaps, and “points of interest” such as hotels,restaurants, museums, and so on. Garmin andMagellan, perhaps the mostpopular makers of handheldGPS units, produce softwarefor this purpose.

Although you will seemaps on your PC screen dur-ing the process of uploadingthem to your GPS, they aren’tmeant to compete with realdesktop mapping software.

Got a Map on YourPC?Desktop mapping pro-

grams, like those fromDelorme, Inc., are designed toprovide high-quality maps todisplay on a PC monitor.These applications allow youto build custom maps withyour own labels and save them

as files. You can print them, too, if you don’tmind burning up paper and ink.

With the boom in GPS sales, some mapprograms now include a GPS menu. The GPSfunctions in map software include downloadingwaypoints, routes, and tracks from your GPSto the map software, and uploading those itemsto your GPS. How many of those functions areavailable will depend on the specific GPS andmap software you own. Two popular map soft-ware producers are Delorme and MapTech.

Be aware that you will need to check thespecific GPS receiver and map software for com-patibility. As new GPS models appear on themarker, as the system software on GPS receiv-ers is upgraded, and as map software is up-graded, some incompatibility will occur. Class,close your books! Let’s go outside and play!

Degree Confluence ProjectLike to travel and take pictures? Enjoy vis-

iting places that are well off the beaten track?Drive a 4WD vehicle? Then get ready for an

Having Fun with GPSBy Anton Ninno, N2RUD, and Jim Kuhl, N2STK

A lmost everyone has heard of the Glo-bal Positioning System by now, andmany radio hobbyists own a handheld

Anton Ninno documents a GPS adventure on the Historic Fortsweb page

August 2002 MONITORING TIMES 15

exciting geographical adventure! The DegreeConfluence Project http://www.confluence.orgis a delightful way to combine all the latest tech-nology: a GPS, a digital camera, and access tothe Internet for some serious fun! By serious,we mean that aside from having fun, you will becontributing to a remarkable set of data for geog-raphy education.

All over the world, people just like you areusing a GPS receiver to become explorers. Theobject is to navigate to a point where latitudeand longitude intersect as integers, meaning with-out fractions. We visited the confluence at 43N,76W, and you can see the report listed underNew York State. At this site, you can explorethe whole planet, or visit your own neck of thewoods. In all, there are more than 12,000confluences to document, so there’s plenty ofopportunity get involved. Even if you don’t par-ticipate, go see the beautiful photos being con-tributed by intrepid confluence hunters world-wide.

Geocaching: the GPS TreasureHunt

When the Clinton Administration turned off“selective availability” (the random error factorbuilt into GPS data by the military to prevent ourenemies from using the system against us), backon May 2, 2000, the accuracy of GPS receiverswas increased from 100 feet to about 20 feet. Thenext day Dave Ullmer created a new scavengerhunt game for GPS owners. He hid a box in thewoods, posted the coordinates on the SatelliteNavigation newsgroup, and challenged readers tofind it. Within months the game was christenedGeocaching by other players, and a website sprangup at http://www.geocaching.com.

Geocaching has been spreading like wildfire.New geocache categories being created by enthu-

siastic players keep the game fresh. Several alter-native sites, like Navicache http://www.navicache.com have appeared, and Buxley’sGeocaching Waypoint http://www.brillig.com/geocaching offers players clickable geocachingmaps. The GPS giant, Garmin, Inc. is introducingGPS owners to the game, and has even added anicon to their operating system for geocachingwaypoints.

The Further Adventures of GPSThink geocaching needs more spice? Like to

compete in sports? Then Geodashing http://www.geodashing.home.attbi.com may be yourgame. The entire planet is your playing field. Thedashpoints you will be challenged to find are muchlike the control points in orienteering, except theyare selected at random. Get the most dashpoints,and you win. The trick will be to find all of them!

If you need an adrenalin rush to get moti-vated, you can go all-out playing Minute War http://www.seaotters.net/~scout/MinuteWar, anotherform of global competition. Here, players com-pete at the same time, no matter where they live,using their own local maps. All the maps havebeen combined for the big game. Each map squareis one square minute of latitude and longitude, andit contains a virtual flag. Players use a GPS to visitthe exact spots required to capture flags and con-trol the squares. Confused? Visit the site to readthe rules and see for yourself – it’s incredible!

Or maybe your interest is closer to geogra-phy than sporting events. You might find a Bound-ary Point http://www.groups.yahoo.com/group/BoundaryPoint expedition to be closer to yourspeed. In a more relaxed manner, “pointers andbounders” visit spots where geopolitical bound-aries meet. Think of the “Four Corners” pointbetween Utah, Wyoming, Arizona, and NewMexico. Tri-state and other multipoint locationsare your targets. Just like your confluence huntingcousins, you will take photographs and recordyour adventures to share on the Net. It’s no coin-

cidence that many recreational GPS websites arelinked to each other!

Having fun without a GPSWe cannot tell a lie. Yes, you can have fun

without a GPS. In fact, there’s group of peoplewho do just that playing a game called Letterboxingat http://www.letterboxing.org. Just imagine

geocaching with no GPS. Instead, players use onlyclues, compass directions, pacing by foot, andsheer brainpower to find letterboxes. If you’reEnglish, you know that’s the common English

The confluence of 49N22E was found in theSlovak Republic by Hans Augdoppler andKlaus Baumgartner.

A boundary point on the US/Mexico borderacross from Tijuana (photographer unknown)

16 MONITORING TIMES August 2002

word for a mailbox. The game began with a guidewho left his calling card on the Dartmoor Heathin 1854. (It was a dark and stormy night!)Letterboxing has become a national pastime in theUK. In April 1998, an article in Smithsonian maga-zine brought it to America. It’s good fun for thelow-tech fellow who enjoys the thrill of the hunt,the challenge of a three-pipe problem, and a longwalk in the woods. Have compass. Will travel.

Outdoorsmen who enjoy photography willfind that hitting trails for a little geo-graphing http://groups.yahoo.com/group/geographing/ willput a new spin on their old habit of shooting uprolls of film when faced with a spectacular land-scape. We take pictures to re-experience the joyof those occasions and to share it with others. Thesame fellow who started geocaching, Dave Ullmer,came up with this new concept: add GPS coordi-nates to your photographs! If you take a 360-degree photography, you’ll really nail down theexperience of being in that particular spot. Thenyou can share it with the group at Dave’s website,if you like. The waypoint will help you find thespot again, if once was not enough.

GPS Goes to SchoolGet ready for a pop quiz. What looks like a

GameBoy, is fun to use, and gets you off thecouch and out into the world? Right – a GPS re-ceiver! Can you think of a better way to teachgeography? We can’t either. GPS is being usedfrom 5th grade up to investigate topics in math,science, and social studies. Jim and I are teacherswho have been borrowing this multi-billion dollarinstructional tool for homework assignments forseveral years. It’s a good thing the GPS systemhasn’t been charged to our school budgets!

Actually, when you compare the cost of abasic GPS at $100 to the cost of a computer, GPSis a cheap deal. Students pay almost $100 for agraphing calculator that doesn’t even receive anyradio signals, let alone signals from satellites. Whynot volunteer to take a GPS to your neighborhoodschool and demonstrate its amazing powers to

GPS receivers are gradually catching on inclassrooms. I began experimenting with GPSwhen a social studies teacher on my middleschool team brought a GPS to school. Her hus-band used it in his boat for fishing. She taughtlatitude and longitude to her students and thoughtit would have more meaning if she could showher students the way parallels and meridians in-tersected near the school. She took her class out-side and using the GPS lined them up along aparallel and a meridian that intersected in theschool’s parking lot.

Many of the concepts you must teach kids(example: latitude and longitude are measuredwith imaginary lines) were taught by the experi-ence. Measuring latitude and longitude took onspecial meaning as the kids found their place onthe lines using the handheld device that remindedthem of their favorite portable game. We findkids are more open to learning about latitude andlongitude when you throw interesting technol-ogy into the lesson.

From social studies we graduated to sci-ence and math. In science class we were observ-ing and identifying the plants and animals on aplot of land near the school. We traditionallyused this activity to involve math students withscience class. Groups in math class would mea-sure the perimeter of our property using metersticks and tape measures. They could use themeasurements of length and width to calculatethe area of the plot of land. In the past, groupsof students would compare their measurementsto determine reasonable dimensions for the prop-erty.

With the GPS we had another way to mea-sure the dimensions of the property. Studentsfound the latitude and longitude of the cornersof the property. In the early days I had them

walk 10 yards on a football field with a GPS toequate change in latitude and longitude with yard-age. There is a site on the Internet that does thatconversion for you. We used these measurementsto determine the difference in density of plantand animal species on the property. Interest inscience, math, latitude and longitude (geography)soared using these high interest, and hands-onactivities. From tests given after the activitiesand other lessons, we found that students wereunderstanding these concepts better than whenwe had used traditional methods to teach them.

After a major change in curriculum in myschool district, I found myself teaching earthscience which included the topics of topographicmaps and (you guessed it) latitude and longi-tude. Enter Geocaching. Students were nowlearning to use GPS receivers and interpret to-pographic maps so they could go on a 21st cen-tury treasure hunt. In addition to finding paral-lels and meridians near the school, they used theGPS to find the coordinates of familiar objectsnear the school. They also learned to enterwaypoints into the GPS and navigate to them.Carrying a topographic map with the GPS gavethem a better understanding of the meaning ofcontour lines.

The activity that really excited students wasplugging a GPS into a laptop computer display-ing a topographic map. The GPS plotted theirevery move on the map. It happened that theschool was built after the map was drawn, sousing the GPS, students were able to draw theschool on the map. As a result of these activitiessome students became so good at reading andinterpreting topographic maps that they werefinding Geocaches without the aid of a GPS re-ceiver.

GPS in the ClassroomBy Jim Kuhl, N2STK

kids? You’ll be a hit in any classroom. We’re livingproof!

While you ponder that possibility, help usspread the word to educators by passing along ourNYGPS website. It’s a mailing list for teacherswho are exploring the use of GPS in school. Theywill also find a treasure chest of resources there,including activities, books, lesson plans, book-marks, and photographs. They’re all free. Here’san example of a virtual geocache for history teach-ers, called Historic Forts: http://w w w . g e o c a c h i n g . c o m / s e e k /cache_details.asp?ID=21378.Geocachers fromall over are contributing GPS coordinates, photos,and stories about all kinds of forts. A player inSweden shares a fort called Kastellet in his logreport.

Having Fun Yet?Try these GPS activities. Archaeologists use

GPS to mark dig sites and the locations of arti-facts. Genealogists use it to mark gravesites andabandoned cemeteries. Historians use GPS to markthe movements of armies on battlefields. There areall the common uses for GPS like hiking, hunting,

fishing, boating, cross-country skiing, cycling, andmountain biking. Spelunkers use a GPS to markcave entrances and share them with friends. Ifyou’ve ever looked for a cave using directionsfrom a looney caver, you’ll appreciate having GPScoordinates that guide you right to the spot. Thesame goes for crazy rock climbers.

Take a GPS and a laptop computer with mapsoftware on your next business trip or family va-cation. It’s not only fun, it’ll save you time andmoney as you plan your route for the best pos-sible outcome. Make lots of waypoints, and sendthem to friends and family by email as you go.They can plot your waypoints with their ownmap software, and see exactly where you are onevery leg of the journey.

Most people like funky old diners. Are weright? Well, here’s a little gift for GPS travelers.We’ve created a virtual geocache called “DinersClub” where players share their favorite diner. Wehad no idea it would be so popular! See for your-self right here: http://www.geocaching.com/seek/cache_details.asp?ID=21289. If you don’t thinkthe adventure of finding good food, recommendedby total strangers, isn’t having fun with a GPS,then we give up. You’re lost.

Anton’s GPS documents his visit to 43N 76W.