When the US Department of Defense developed and launched the Global Positioning Satellite (GPS) system back in the early 1980s, I am sure that they did not foresee that this system would some day provide hours and hours of recreation for thousands on people of all ages as they took up the hobby of “geocaching.”
The GPS system was first developed to aid the military to precisely navigate. It uses a series of satellites that continuously broadcast a special radio signal that contains a time signature. Each of the 30 GPS satellites situated in orbit above the earth broadcast the same time signature. If your GPS receiver can simultaneously access the signals from at least three of these satellites, it can plot your current position on earth. The GPS receiver calculates how long it takes for the radio signal to arrive from each of the three satellites. You might remember from High School Physics that radio waves travel at the 186,000 miles per second, so each of the time signatures will arrive at the GPS receiver at a slightly different time. Using this information and mathematic calculations, the GPS receiver plots your current position.
This is the same system that is used in some cars to tell you how to get to Aunt Ida’s house for the Memorial Day picnic. It is also the system that in an emergency is used by some cell phones to tell the 911 Operator where you are located. And it is the system that allows people to take up the hobby of geocaching.
I have to admit I was ignorant of this geocaching phenomenon until my sister-in-law, a person prone to try just about anything, introduced me to its nuances. A number of years ago my wife, knowing that I love all things electronic, gave me a hand held GPS unit for my birthday. We used it sparingly on car trips and a few times on some long distance bike trips, but for the most part it lived a very sheltered life in the glove box of my car. When my sister-in law found out I had a GPS, she borrowed it and has been geocaching ever since.
Beginning in about the year 2000, people began hiding small “caches” throughout the United States. The cache might be a plastic container or a small metal box. Some are as tiny as a 35mm film container or as large as a loaf of bread. Inside the container will be a log for you to sign when you find it and perhaps a few trinkets to share with the kids. The person hiding the cache makes a note of the longitude and latitude of the location using a GPS receiver to find the coordinates. The locations of these caches i.e., latitude and longitude, are then posted on the web site www.geocaching.com .
Some caches have “travel bugs,” that look like dog tags. Cachers are asked to move them on to other caches to see how long it takes to travel to various destinations. Some are called shutter bugs and contain a tagged disposable camera. Finders are asked to take a picture of their group and return the camera to the cache.
If you go to the web site and type in the zip code for Harrison (45030) you will find the coordinates for more than 1000 caches hidden right under our eyes. I am told that they are always located on public property, i.e., parks, school yards, library grounds etc.
This is a hobby for all ages. There are also geocaching clubs. The local one is Ohio Kentucky Indiana Cachers, www.okic.org. Geocaching provides a great opportunity for entire families to get some exercise, practice some math and science and have a great time looking for caches. All you need is time, a GPS receiver, and some good eyes.
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