A SPORT FOR THE 21ST CENTURY!
FOR CENTURIES, travelers and explorers have navigated land and water
using tools available for their times. The sun, the stars, astrolabes, compasses,
gyroscopes, chronometers, cross-staffs, sextants, charts, maps, radio, radio detecting
and ranging (radar), Loran hyperbolic navigation and, today, satellite-based electronic
Global Positioning System (GPS) have helped wanderers plot and plod from point to
GPS was initiated in 1973 by the U.S. Department of Defense as the Navigation Satellite
Timing and Ranging (NAVSTAR) system. NAVSTAR used 24 satellites to aid in pinpointing
locations around the world. For national security reasons, an intentional error
called selective availability (SA) was programmed into GPS, limiting accuracy for
civilians to about 300 feet ? about the size of a football field. On May 2, 2000,
SA was disabled, improving accuracy to within six to 20 feet for everyone who wanted
to use GPS technology.
IMPROVING GPS ACCURACY
– DGPS AND WAAS
GPS satellites each weigh about a ton and are 17 feet across with their solar panels
extended. Solar powered with battery backup, they have life expectancies of about
10 years, when they’re replaced. The 24 satellites orbit the earth at about
12,000 miles twice every 24 hours. To do this, they’re cruising through space
at about 7,000 miles per hour.
Location and timing are critical to the information relayed by the satellites, and
the likelihood for errors is constant. GPS has been made more sophisticated over
the years to counter those errors, and GPS receivers reflect the system’s
DIFFERENTIAL GPS (DGPS)
– The U.S. Coast Guard operates a series of towers that help to correct the
satellite system’s errors by adding the constant of fixed (land-based) checkpoints.
DGPS technology improves accuracy to between one and five meters (about three to
WIDE AREA AUGMENTATION SYSTEM (WAAS)
– The Federal Aviation Administration has implemented a network of
25 ground reference stations in the United States, Canada and Mexico. These feed
information to a master station that broadcasts corrected latitude, longitude and
altitude information. WAAS technology improves accuracy to within three meters (10
GPS Stash Hunt
A computer consultant named Dave Ulmer wanted to test the accuracy of the GPS signals.
On May 3, 2000, he hid a bucket in the woods near Beaver Creek, not far from Portland,
Oregon, and he measured the bucket’s coordinates with a GPS unit. Ulmer then
posted its coordinates on the Internet for a user’s newsgroup and called the
search for it the “Great American Stash Hunt.”
The bucket contained a number of prizes and a logbook for seekers to sign. For those
who would find the stash, there was only one rule: “Take some stuff. Leave
It only took a few days for Internet users to find the stash and talk about it online.
Other stashes were hidden, and by the end of the month, the term geocache
was coined to describe the hidden “treasure.”
The word geocache combines geo (for “earth”) with
cache (for “a hiding place” or for “computer storage”).
Geocaching was adopted as the official name of the game on May 31, 2000.
You might consider geocaching a sport or a game. Either way, the number of its participants
has grown exponentially since the beginning of the millennium. Today, there are
more than 200,000 active caches in 218 countries around the world.
Geocaching has a number of guidelines – not rules, as such. You need very
few things in order to play.
Basically, someone hides a box containing treasures (books, CDs, videos, key chains
– limited by imagination only), noting the coordinates of the hiding place
with a GPS unit. The hider then posts those coordinates on the Internet –
www.geocaching.com is one
of the sites on which to post and find locations.
Seekers who want to look for hidden treasure in the area of the hiding place will
find the posted location on the Web site and use his or her own GPS unit to try
to find it. When the seeker finds the hiding place, he or she signs the enclosed
logbook and swaps treasure. The seeker also can log the find on the original site
on which the coordinates were first listed.
It sounds simple. But terrain and the nature of the area in which the treasure is
hidden can make the seeking difficult.
The www.geocaching.com Web
site and a number of reference books on geocaching list variations of the game.
Time is the mother of invention for geocaching, and the number of variations on
the theme of high-tech hide-and-seek continues to grow.
MULTIPLE CACHES – The seeker is required to go to at least two locations
prior to finding the hidden treasure.
VIRTUAL CACHE – There is no hidden treasure at all, but a unique object
like a monument to be found.
SHUTTERSPOT – Participants try to find and log by latitude and longitude
the exact spot where a photographer stood to take a posted photograph.
GEOSNAPPER™ – Nextel camera phones with proper software “geotag”
photos, which are categorized, searched and shared on www.GEOsnapper.com.
GEODASHING – Participants around the world race to find randomly selected
waypoints, or dashpoints. Whoever finds the most dashpoints wins.
GEODASHING GOLF – Players use GPS receivers to navigate to 18 randomly
placed waypoints (or nine in a short course). The closer to a given waypoint, the
lower the score, and the lowest score wins.
MINUTEWAR – This game of capture-the-flag divides local maps into squares
that are one minute of longitude wide and one minute of latitude long. Each square
contains a virtual flag. Participants start at the same time to visit these spots
to capture the flags.
BENCHMARK HUNTING – More than 700,000 U.S. National Geodetic Survey
markers can be found in the United States. Find nearby locations at www.geocaching.com.
TRAVEL BUGS – Players move these trackable “hitchhikers”
from place to place. Their logbooks tell their stories.
THE DEGREE CONFLUENCE PROJECT – The project’s goal “…
is to visit each of the latitude and longitude integer degree intersections in the
world, and to take pictures at each location.” Photos and stories are posted
EVENT CACHES – The listings have time elements that bring participants
together for designated activities, such as picnics.
MICRO-CACHES – These feature tiny containers, which are better to hide
in an urban setting to avoid alarming people.
AUTO RALLIES – Rallies already require a sense of direction, so a GPS
receiver is likely to be part of the equipment. Navigation exercises are especially
fitting for off-road events.
As with any outdoor endeavor, your approach and the correct gear can be critical
for comfort and safety while hiding or seeking a geocache. Organize and be prepared!
Here are some of the things that will help make your geocaching experience a good
HAVE SOMEONE WITH YOU. The “unknown” can be dangerous –
even if that unknown is as simple as a hole into which you’re about to step.
Two sets of eyes are better for keeping track of where you are, especially when
one set is fixed on the coordinates of a GPS unit.
BE AWARE OF YOUR SURROUNDINGS. Even when you’re with
someone else, watch for thorns, low-hanging branches, cliffs, unfriendly wild animals
and other normal natural “hazards.”
CARRY AND DRINK PLENTY OF WATER. Depending on the location’s climate,
dehydration can be more or less of a safety factor, but it’s always a factor.
For long, involved searches, a water filtration system might be in order.
TELL SOMEONE WHEN AND WHERE YOU’RE GOING. Mom’s admonishment
to “call when you get there” still applies, only it doesn’t have
to be Mom. When traveling in a remote location, anything can happen, so make sure
someone knows your intentions and approximate schedule.
MARK YOUR CAR’S LOCATION AS A WAYPOINT ON YOUR GPS UNIT. Like Hansel
and Gretel’s fabled bread crumbs, a waypoint (which is like a flag on a map)
will help mark the way back. The difference is that GPS uses satellite navigation,
which is more accurate and also less likely to be eaten by animals than bread crumbs.
HAVE THE NECESSARY HIKING GEAR, ESPECIALLY WHEN YOU’RE TAKING THE PATH LESS
TRAVELED. Outdoor gear for geocaching involves more than a reliable GPS
receiver (and power cord for use in your vehicle). Proper gear includes:
• Map of the area and compass (these are of critical importance)
• Weather-appropriate clothing
• Flashlight and batteries
• Batteries for your GPS receiver
• Notepad and pen in a waterproof bag
• First-aid kit
• Signal mirror
The Sum of Geocaching
Geocaching is simple in concept, but involved in its pursuit. It integrates the
high technology of computers and hand-held electronic equipment reading signals
from satellites with some of the most relaxing and beloved of pastimes – being
outdoors, hiking and discovering new things about the world around us.
For more information, visit www.geocaching.com
and www.garmin.com (“About GPS”).