On the road…again!
Afghanistan to Zambia
Chronicles of a Footloose Forester
By Dick Pellek
What’s the Address of the Devil’s Tower?
Most young adults these days know enough about GPS technology to find a street address in a strange city by just looking it up on a smartphone, or an iPad, or a dedicated GPS device. And when their car also has an embedded GPS system or one that plugs into the cigarette lighter, getting from home to that specific address can be accomplished without the apprehension of years gone by.
Commercial Global Positioning Systems (GPS) are now proprietary entities derived from the outgrowth of a broader technological field originally described as GIS, or Global Information Systems. Since the applications of both GPS and GIS technologies are satellite-based and worldwide in scope, GIS and GPS tech are routinely used in virtually every country. What is it about them that makes their components both revolutionary and unique? Let’s ease into the sophistication one step at a time.
Suppose we want to visit the Empire State Building in New York City. How do we get there by road from across the Hudson River in New Jersey? And once we arrive in the heart of The Big Apple, how best to find it without getting lost or wasting time by taking wrong turns? The most obvious way would be to look up the address, which happens to be 350 5th Avenue. Or we could key in the words Empire State Bldg. and conduct a map search on our handheld GPS or the one in our modern car.
Once we know the street name, most GPS devices let you type in the street number first, followed by the name of the street and the city and state where it is located. Although we may not be aware of what is going on within the device, having the destination city and state are also important inputs, lest the GPS unit sends us across the country in the wrong direction in search of a town with a common name, such as Springfield. There is a Springfield in every state so we need to zero in.
Most of the data in GPS devices are stored in distant servers and relayed to satellites orbiting in space. After the combination internal-external GPS system databases locate the address we want, by virtue of an electronic dialogue among satellites in space and receiving stations on earth, our device may plot a map route to the destination and insert a stick pin at the point on the map that represents our intended destination.
When we arrive at our destination at the Empire State Building at 350 5th Avenue in New York City we should note that the street address corresponds to its geographic coordinates of latitude 40° 44′ 54.56″N and longitude 73° 59′07.25″W. Written another way, in decimal notation, the coordinates are 40.748445° lat. and -73.985429° long.
We may never have a need to remember the geographic coordinates of the Empire State Building, but there are plenty of places and important land features that do not have street addresses or do not occur in towns or cities that we might want to remember, down to a few feet of radius.
For outdoorsmen, explorers, scientists, sailors, and researchers; recording the geographical coordinates helps us to archive the exact location of a campsite, a new route, an archeological discovery, or the place where there may be buried treasure—in the middle of a forest or on the high seas. In the case of the discovery of the sunken HMS Titanic, those coordinates had been kept secret in order to discourage unwanted looters.
Finding a particular spot on the ground in the middle of a forest or on the high seas requires a quantum leap in understanding of the ABCs of GPS technology. The approaches are entirely different from looking up an address but are complementary in regards to data components. On the one hand, telling someone from New York City to meet you at the Empire State Building is one thing, but telling them to meet you in Central Park is quite another. The broad 10,000-acre parcel of land area that comprises Central Park is too expansive as the sole description of a meeting place. If you pinpoint the location for a Central Park rendezvous as 40° 46′ 55.41″N and 73° 57′ 55.53″W, you should see them when you arrive.
When the destination point is in the middle of a forest, however; the geographic coordinates do matter because there are no street addresses. Neither are there any street addresses in the open rangeland of NE Wyoming where the Devil’s Tower is located. But the GPS coordinates will tell us that the magnificent rock formation known as the Devil’s Tower has a global address of 44°35′25.88″N and 104°42″57.31″W.
Photo Credit: Thu Pellek
Getting back to the everyday uses of GPS, it is easy to learn the geographic coordinates of both the starting point and the destination shown on Google Earth or similar maps, because they are embedded as part of the active screen on the computer monitor. Walking or driving directions between the points are derived by providing an algorithm solution of transit choices between the two points.
In the case of knowing the coordinates of a newly discovered site, it requires the GPS user to be on-site; and only then to note what the satellite data tells the user about his/her exact position on earth. Since the heretofore unknown site may not be part of any known data archive, plotting a route can only be initiated at the site itself, and traced back to the initial starting point.
Many practical applications have evolved from improved GPS technologies. A few true and memorable examples come to mind. If the geographic coordinates of an obscure, remote 30-year-old experimental fruit nursery in Haiti were generally known, it would be possible for present and future researchers to go directly to the site without the need for paper maps that don’t contain the information; or the need to have as a guide one of the very few local people who personally remember where the nursery is. As things now stand, the original records of the plantings have been destroyed in a fire. For all intents and purposes, all useful scientific knowledge has also been obliterated.
Another example of the value of recorded geographical coordinates as part of research field notes pertains to field investigations in soil science. Only a handful of people in the world care about knowing exactly where rare soil monoliths of Cape Verde inceptisols came from; and even fewer people would be able to take them to the place where they were excavated, if they ever wanted to see for themselves. The dozen or so magnificent specimens of Cape Verde inceptisols that were skillfully extracted and preserved in 1985 represent the only ones in the world. And the man who did the extractions worked alone and presumably is the only person in the world who can lead an interested researcher to the several spots in the landscape where he obtained his specimens. The specimens themselves, fortunately, have been preserved as museum pieces in a soil science laboratory in Lisbon, Portugal.