Who Needs GPS?
Most of you have probably heard of GPS (Global Positioning System). Originated by the U.S. Department of Defense (DOD) for military reasons, this technology has grown, as has its availability.
The basic idea is as follows: Orbiting the Earth are a number of satellites, whose purpose is to tell any reciever that may be tuned in its location on the Earth's surface. By reading signals from at least two, and hopefully three or more of these satellites, the reciever will then report its location. This readout varies; latitude and longitude or coordinate systems are the most common types used.
The accuracy obtained by the reciever is dependent on several things. In the past, the most aggravating were the built-in errors in the signals sent by the satellites, called selective availability. Additional hardware and/or software was required to remove, or at least minimize, these errors. The DOD has control of the signal quality, and their original claim was that these errors would foil any enemies of freedom that may be lurking about, ready to pound clean-living capitalists with super-accurate artillery fire.
With the widespread availability of DGPS (the "D" is for "differential") recievers and advanced software programs that can greatly reduce these signal degradations, producing sub-centimeter accuracy for the Land Surveying field among others, the continued signal degradation seemed more commercial than strategic. After all, if you were producing GPS recievers that normally achieve only fifty-foot or so accuracy, and also selling DGPS "add-on" equipment with which one can get sub-meter accuracy out of the same unit, would you want to stop these intentional errors? Heck no, you're making too much money out of this.
Edit: It's been years since the government announced the end of selective availability, but my GPS unit still goes strange on me from time to time. Perhaps it's been quietly brought back.
Having had my say on that subject, let's look at how GPS can help the hunter. Not long before writing this article, I obtained a Garmin GPS II Plus handheld reciever, which cost about $250. It's the first one I'd owned, and it's a nifty little thing. I bought it for one basic purpose: To map my hunting area.
Apart from its biggest failing, which is no fault of its own ("selective availability" of DOD satellites), it has proven to be a fine tool for this purpose. I worked as a land surveyor for years, and I walk (or drive) the back roads and trails storing waypoints at significant features like bends in the road, perimeters of clearcuts, etc., and then I take it home and manually enter the coordinates for each point into my computer (using AutoCAD), then connect the dots with lines, and eventually I'll have a map.
By marking spots on my map where I've found deer sign or seen deer and then comparing the overall lay of the land, I can get a much more complete picture of where the deer are likely to be, and where I should position myself to intercept them. By marking waypoints in latitude and longitude, you can also plot points of interest on USGS topo maps, which have the advantage of illustrating changes in ground elevation.
You can also use your GPS to get yourself "un-lost" if you need to. Say you park along a dirt road in the forest, and head off into the woods. Did you take note of the direction you were walking when you left? The direction the road was running?
No problem if you marked a waypoint in your GPS reciever before you left and called it "truck." When you realize it's getting late and you need to get back, use your GPS's "goto" function to provide you with a direct course back to your vehicle.
You don't even need a compass, at least with the Garmin; it'll provide you with course directions, and as you walk, it'll direct you to turn right or left in order to stay on course. But it saves battery life to get a bearing from the GPS, then turn it off and use a compass to follow that bearing. From time to time you can turn on the GPS unit to correct or verify your course.
The same applies if you shoot a deer and are unable to drag it out alone, or if you have to track one; mark where he was when you shot him, then mark a waypoint at each place where you find blood or other sign. If you run out of sign, a glance at the overhead view screen may show that he was headed in a constant direction, and you can try heading that way. And if you need help, "goto" your truck and go get some buddies, then "goto" your "shotdeer" waypoint and find him!
What I'm trying to say is that a GPS reciever can be very useful, though not always a necessity. I prefer to use mine when hunting unfamiliar territory, and the terrain lends itself to getting lost easily. The woods near my home are varied, but a few miles down the road there are acres and acres of continuous slash pine woods, and it all basically looks the same. Since the sameness tends to help one lose his way, that makes it a good bet for GPS. In a case like that, it's just good insurance.
-Russ Chastain
