GPS's and Digital Mapping Software

GPS's and Digital Mapping Software (Revisited)

There is a hiking buddy of mine, who often signs his email messages as "Chief War Fugawi" (think about it) used to have a T-shirt that said "You're not lost if you don't care where you are!" This seems to be sort of the "What!? Me worry?" approach to route findings on long backpacks. Of course, that is not really his style, nor is it really mine. It is important to know where you are , if for no other reason that to have a sense as to how far it will be to get out, and get a real shower. I have discussed global positioning systems (GPS) and software for hikers over the past couple of years in the Tennes-Sierran. But like any emerging technology area, a couple of years back can be nearly ancient history, because changes come so quickly. What was absolutely the latest greatest gismo 9 months ago is practically a technological dinosaur today. There have been some major improvements, and the technology is maturing, so I thought it would be worth another look.

First, hand-held GPS devices. Unless you have been living under a rock for the past few years, you have probably heard about these things. GPS units are basically small satellite receivers, with a built-in computer. They can be used to figure out where you are on the planet. Without going into a lot of detail, (if you are really thirsty for more knowledge, try looking at the following URL: (wwwhost.cc.utexas.edu/ftp/pub/grg/gcraft/notes/gps/gps.html), basically, there about 24 GPS satellite transmitters orbiting the earth, a little over 12,000 miles up. (Note that such is not high enough to be in geo-synchronous orbits, so the satellites do cross the sky overhead.) They send out signals, which essentially say 1) my name is such and such 2) my location in the sky is this, and 3) this is the exact time that I sent out this signal. The hand held GPS receiver, which stores all these orbits in its memory, gets the signal about 65 milliseconds later. And now the calculator in the GPS goes to work and figures: let's see. If that signal was sent at exactly 4:08pm Greenwich Mean Time, and I received the signal from satellite # 22 exactly 72.6298453 milliseconds after it was sent, and electrical waves travel at the speed of light, which is 186,000 miles per second, then satellite #2 is exactly 13,509 miles, 798.47 feet from me. And Satellite #14 just sent out a signal, etc, etc. Once the GPS receiver gets signals from 3 or 4 satellites, it knows to within a few inches of where it is on the face of the planet. (What is really amazing is that the clock on these GPS's is so accurate. It is the most accurate clock you will likely ever own, because it gets updated from the satellite clocks all the time.) If you want to learn a bit more about how GPS works and how you might use it, go to our GPS Tutorial

So that is how they work. What is the news about these devices? In a nutshell, there are five major improvements that may make you want to reconsider if you do not already own one.

Much lighter weight. Most of the hand held devices a few years ago (like 3 or 4) weighed well over a pound. Now, especially if you load them with lithium batteries, rather than normal alkaline batteries, you are talking about 8 or 9 oz. Big improvement. They are also smaller, and easier to manipulate in the field.
Vastly more sensitive. Most devices are now 12-channel receivers, which means they can monitor the signals of 12 satellites simultaneously. Most important for those of us living in the Southeast, they now work under heavy tree canopies. The older devices simply would not compute a position unless you were out in the clear. Fine for out west, but not very useful in the Smokies.
Faster response. It used to be that you could figure 5 minutes under ideal circumstances to get a fix. Just for fun, I took my new unit out under the worst possible (for a GPS) conditions: it had been more than 1500 miles since I last turned it on, and when I did turn it on, I was in a climax forest, which passes for my back yard. I had a fix in about 3 minutes. Then, a couple of hours later, I turned it on under open skies: 30 seconds to get a fix.
Cheaper. Like any new technology, the prices have come down. You can buy the less expensive ones for about 100 bucks at K-Mart. You can get lots of bells and whistles for $250, and for a bit more, well, you can have built-in maps displayed, and color screens. (I settled for mid-range. You have to draw the line somewhere.)
Easily configured and integrated with computer mapping software. I will talk about mapping software below, but with a $40 cable, you can upload pre-planned waypoints to your GPS at home, or you can mark your route in the field, and find out where you REALLY went when you get home.

All this said, these units are still no substitute for map reading skills. But then in my opinion, if you don't know how to read a topo map, you shouldn't be out in the backcountry anyway. But the GPS is a great adjunct to good map reading skills, and I think that using a GPS along with topographic maps can help you learn more about the landscape. For those of you that are still not convinced, I figure there are at least three situations that come to mind where GPS units can be especially helpful: a) in high elevations, in the fog, if you can not see surrounding peaks to get a compass fix; 2) looking down into a sea of canyons from a plateau, and trying to figure out which one you need to get into. Believe me, I have tried this many times, and it ain't as easy as it sounds; 3) trying to get a simple fix under heavy vegetation, in complex terrain, like the Smokies.

I alluded to mapping software above, and as I said, I think it is worth a revisit. A few months ago, I reviewed a product call TOPO!. If you don't remember, TOPO is basically the electronic equivalent of a whole bunch of topographic maps pasted together seamlessly. You can scribe a route across the map, and TOPO! will generate distances, elevations, and all sorts of other data. When I did the review, my main beef with TOPO! was that it was still using a 16-bit (that is, Windows 3.1-like) interface, with all the attendant problems, and there were difficulty printing the maps. And, coverage of key areas was, well, non-existent. But with the release of the free upgrade, TOPO! Version 2.0 (you can download it free from their web site: www.topo.com), Wildflower Productions has fixed the interface problems, added some GPS capability, and the printing goes smoothly. Furthermore, they are releasing lots of new maps sets. Big improvements! For Tennessee residents, there is a set available for $49 that covers the entire Great Smoky Mtns. National Park, the southern Cherokee and Nantahala National Forests, North Georgia, and Atlanta.

In its December, 1998 issue, Backpacker Magazine rated MapTech's Terrain Navigator (TN) slightly higher than TOPO! So armed with the excuse that there were some important areas not covered by TOPO! (as of now) that were covered by TN (namely southern Utah's canyon country), I felt compelled to buy the latter and give it a try. The first thing you will notice about MapTech's maps is that they are not cheap. Coverage of an entire state will set you back $300 or more. Of course, there are a lot of hikers out there that really do not want quad maps that cover an entire state. But you may find yourself needing more than one of the typically-$99 CD's to cover your favorite hiking areas. (Note that MapTech does not have any products yet for Tennessee, except for a $29 CD that covers the Great Smoky Mountains National Park in total. The coverage of the southern Nantahala Nat'l Forest will cost you $49, and there is nothing for northern GA yet. I list this so as to provide a direct as possible comparison with the TOPO! product.)

The interface of TN feels a little slicker than that of TOPO!, but with the exception of "quickie" elevation profiles, there is not a lot of difference in the interfaces. But the best way to describe TN is to compare it with TOPO!. TOPO! is really designed for hikers who have a sense of where they are (at least, where they want to be) and where they are going. That is, in TOPO!, the entire map field is truly seamless. You just go on and on, as you cover the terrain. In contrast, TN seems to be designed for people who have to know which quad they are on. TN gives you an overview map, with the quads on it, and you cursor over them until you hit the right map name. The best you can do with TN is to turn on it's two-map view. That is a nice feature, but it is unnecessary with TOPO!, because all the quads are cemented together. This is a huge advantage, if you have a 4 or 5 mile hike that cuts through 4 quads, like ours did a few weeks ago. TOPO! uses 5 map levels you can bore down into, compared with 2 for TN (the 1:100,000 and 1:24,000 scales). Oh, one other difference: TOPO! provides you with an instruction manual, TN's instructions are built into its help file. For my $$, TOPO! is a better product for hikers, but you may decide differently. The nice thing is that you can get demos of each of these products at their respective web sites (www.topo.com, and www.maptech.com) so you can get the "feel" of them before you plunk down your hard earned money.

Both of the products offer extensive support for GPS users. (The basic TOPO! 2.0 package has more limited support. However, for a one-time $39, you can upgrade to TOPO!GPS, which has all the features of TOPO! 2.0, plus heavy duty GPS support. TN has this level of support built into the standard, albeit more expensive, package.) First, both packages permit you to mark points on the maps, and store them as GPS "waypoints." Waypoints are just that: a point along the way. For example, you might want to know the coordinates of your 3rd night's camp. Or a critical trail junction that you can see on the map, but the hiking guide indicates is un-signed, and near several other trails. You can also produce "routes" with the mapping software, which are an entire series of waypoints along the route that you plan to hike. Maybe you want a "marker" every mile or so, or every half mile, or every hundred yards, if you are really into waypoints. And both packages (if you have a computer communications cable for your GPS) support direct uploads of the waypoints you have created with the mapping software to your GPS. They also support downloading of the waypoints from your GPS that you mark as you do your hike. Essentially, you can see where you have been, if you are not sure by the time you get home. This is especially useful for cross-country travel.

Someone who is slightly familiar with maps and GPS units, but has not used them extensively might ask: "Why go to the bother of uploading waypoints from your computerized map to your GPS, when you can just enter directly from the GPS unit as it is held in your hand?" That is a legitimate question and one that I used to ask, until I started entering lots of waypoints by hand. If you think about the process you have to go through for a bit, the benefits of direct uploading become obvious. For example, suppose I am going to do an off trail hike in the Sierras, one which will take me out for 5 or 6 days. Because the guidebook has indicated that it is important to be careful to pick the correct pass to hike through on day 3, because the alternatives are dangerous, I would really like to program in the waypoint for Carol Col into my GPS to make sure I get to the correct pass. Without the GPS capability of the mapping software, before I leave on my trip, I get out the topo map, and get out my yardstick to grid the map with coordinates in the area of the pass. Of course, I will have to do some estimating, because there is some error in my lines as I have drawn them on the map. Then I do a bit of extrapolating with a ruler to get the exact position of the pass. Let's suppose it is in Zone 11, 347,256 m Easting, 4,126,997 m Northing. (For those of you unfamiliar with Universal Transverse Mercator (UTM) coordinates, they are much easier to use that latitude and longitude.) So with that information, I turn on my GPS, page to the waypoint screen, and start manually entering the waypoint name as CRLCOL for Carol Col. Since data entry is by scrolling through the entire alphabet and a list of numbers from 0 to 9, each letter or number entry may require 10 - 20 clicks of the scrolling button. So to enter a 6 letter name, you need to perform maybe 40 - 90 clicks. Then it is time to enter the coordinates, which requires scrolling through the number list too, and each UTM coordinate has 2 zone digits and 13 actual coordinate digits to scroll through, so you may have another 50 or 75 clicks. Is your thumb tired yet? Actually, it is not as bad as it may sound, but it does get a bit tedious if you want to enter and name 5 or 10 waypoints.

OK, let's see what the process is like with the mapping software and interface cable. First, you click on your waypoint tool in the software, then move your mouse to the point on the map you want to make as a waypoint. You click on it, and type in the name that is compatible with the naming conventions of your GPS. (If it takes you longer than 3 seconds to type in "CRLCOL," maybe you need to be buying typing instruction software, as opposed to mapping software.) When you have mouse-clicked on and named all the waypoints you want, you turn on your GPS and plug in the cable, click on the download wizard, and in about 1 or seconds, all that waypoint data is now stored in your GPS. Nifty, huh? The bottom line is that it is a lot quicker to do the waypoint entry on the computer at home than on the trail. On the other hand, I would still rather be sitting around a campfire in the mountains, trying to enter waypoint data by flashlight and taking forever to do it, than sitting in front of a computer at home, doing it quickly. Of course, doing it at home helps me anticipate or savor the hike even more, and that can't be bad. And maybe that is a large portion of what this is all about anyway.

Note: As of January, 2000, both TOPO! and Terrain Navigator have undergone important improvements. You can download these free updates from their respective web sites. The most important of these has been addition of seamless mapping to Terrain Navigator. This makes more it useful to hikers. Also, this winter, Delorme began selling their new 3D TopoQuad product. These maps include the real 7.5 minute USGS topographical maps, and add a three dimensional viewer to the maps which is kinda neat, but not particularly accurate. The good news about this product is that for many states, you can purchase all the topos for about $120. A big downside for hikers with GPSs is that inexplicably, there is no option to provide coordinates in UTM format. Look for a more detailed review later.

� Roger A. Jenkins, 1999, 2002