Using GPS Receivers

[SeattlePioneer]

Our Council had a three hour class a week ago on using GPS receivers taught by a Scoutmaster of vast experience. It was very well done.

 

He began with a discussion of the fundamental skills of using a map, compass and altimeter for routefinding. I thought that was a good idea.

 

Hw went on to discuss how the GPS system worked, including it's strengths and weaknesses. A discussion of the UTM coordinate system that makes it fairly straightforward to locate your position on a map from co-ordinates, or to do the reverse was practiced.

 

A discussion of map datums and their importance was discussed, and everyone had a chance to set their GPS receivers to acceptable settings.

 

A short hike gave participants practice in setting waypoints and then using a compass to navigate back from waypoint to waypoint, rather than leaving the GPS receiver on all the time.

 

Very well done. Probabably 100 people or so, including some youth members attended.

 

 

Personally, I just need a map about 90% of the time to find my way. Another 9% of the time I use a map and compass. Less than 1% of the time do I need my GPS receiver, usually in fog when I'm boating or whiteout conditions in the backcountry.

 

But having a command of skills associated with a GPS receiver is useful, m and I learned some usefull skills at this training. In the future, I'll probably take the time to set more waypoints as I travel, even if I don't expect to need them. I've decided they are cheap insurance against problems.

 

 

So---

 

When do you use a GPS receiver, and how sure are you of the skills needed to use it accurately and effectively?

 

 

 

Seattle Pioneer

 

[kenk]

Sounds like a great class.

 

For some reason I find myself having to keep relearning how to read UTM coordinates over and over. I'm not sure why they don't stick in my all too old brain.

 

Here is a link to a great sight regardng use of UTM coordinates: http://www.maptools.com/ . I purchased their UTM grid tool and like it.

 

Another interesting site, though not as useful: http://www.kifaru.net/forums.htm

 

My favorite book for GPS use is "GPS Land Navigation" by Michael Ferguson. The section on selecting GPS's is certainly dated, but the rest of the book is excellent.

 

I do wish the USGS topo map for my area came with UTM grids pre-printed. As I understand as maps are revised the grids are added, but that hasn't happened for those in my area yet.

 

[packsaddle]

Hey Kenk, Those tangled placques are really annoying, aren't they?

 

But seriously, as a troop we discourage GPS use by the boys unless they have mastered map and compass skills. However, having one along on a backpack trip is useful to determine position along a route. This is especially true if we're paddling a big lake and trying to decide which island we're supposed to camp on. In each of those cases we download the map segment that's relevant and superimpose the known waypoints or our traveled route. The only problems occur in deep canyons and heavy forest where the satellites can't be received. Then we rely on those maps.

[AvidSM]

I use them as a pedometer. Last time we were at Gettysburg, I used one to get accurate milage for the two trails, Billy Yank and Johnny Reb. This information goes into the boys records for miles hiked. (BTW, the milage on the Billy Yank trail is a few more miles than what the book says)

 

I also use them on backpacking trips. I get the endpoint coordinates off of the topomap web site and program it in. That way, I know how far we have gone and how much more we have to go.

[CA_Scouter]

We just used our GPS receivers for a geochache hunt. For those of you not familiar with geocaching, that's when someone hides a sealable container somewhere, posts the coordinates on the internet, then you try to locate it. The container usually contains a logbook, some trinkets to trade with, etc. When you find the cache, you note your entry, take/leave a trinket, then post your experience when you return.

 

We did this on our last outing, and managed to make it a 7.5 mile hike. We then hid our own cache, and posted it. Just yesterday, I saw that someone had found our cache and posted a response. ( we also worked in some compass exercises ).

 

Pretty interesting stuff, and you could really get into it if the game appealed to you.

 

We also use ours primarily as a pedometer, mostly because we adults haven't figured out all the intricacies of the units just yet. Working on that though...

 

http://www.geocaching.com

 

[EagleDadx3]

My first encounter with a GPS was up at Camp Mac in northern Wisc. Another Scouter had one (they were fairly new and very expensive at the time) and once we got to our site, he told us that the parking lot was 150 yards and pointed in the direction on his new GPS. I told him "Yup!"

I received one as a gift last Christmas and found it useful to hold down the map on windy days. Now that I've figured it out a little, we use it to measure distances traveled either on foot or bicycle. We also found a GeoCache at Indiana Dunes. It was an old ammunition box with trinkets inside. The boys added a patrol patch. It was a Family Campout (our troop invites the whole family to a campout in early fall, just to find out why we don't invite them the rest of the year), anyway, one of the scout's sisters actually found it while the boys were trying to zone in on the coordinates using the GPS. She went on and on about it and left a hair scrunchee in it and wrote the story on the notepad.

Basically, the GPS is a fun toy. The kids like to borrow it to track hikes and stuff.

[orennoah]

I did a presentation on using GPS on Scout outings at our district Round Table as one of my Wood Badge tickets. (If anyone wants a copy of my written presentation, please PM me.)

 

I started off by telling a true story. I was an ASM and backpacking with my troop for the first time. I had a compass, a USGS topo and I knew (from my Scouting days) how to use them. I also had the brand new GPS receiver my wife had given me. I thought I was a land navigation god. I was wrong.

 

We started hiking and the sun dropped, leaving a moonless night. Compass and map weren't all that useful at that point. Not to worry, as the SM had done this route many times before. We hiked on.

 

Periodically, I would check my GPS and it would have a nice symbol "showing where I was," but I couldn't tell where that was in relation to the campground we were going to.

 

At one point, the SM stopped and declared that we must have missed the trail junction, because the river was on our left and not our right. We ended up camping somewhere on the trail, but I couldn't tell where we were. My GPS gave me the longitude and latitude of where we were, but I couldn't figure out how to translate that into a point on my map.

 

I was embarassed, especially in light of the SM's "tsk, tsk" attitude about GPS and my skills. I recorded our "campsite" as a waypoint and vowed to figure this all out when I got home.

 

Hence, I studied about datums, the UTM and learned how to translate from map to GPS and GPS to map. Then, it transmuted into a Wood Badge ticket item.

 

I think that GPS is great augmentation to traditional map and compass skills. It certainly can never replace them. However, using a map and compass on a moonless night, during whiteouts or greyouts or in featureless terrain can vary from daunting to impossible. GPS can still function in those conditions.

[SR540Beaver]

Map and compass are primary and come first. The batteries will never run out on a compass. That being said, don't sell a GPS unit short. Toy? How do you think the military drops those "smart" bombs down the enemy's chimney? If they can do that, just imagine what you can do with one when you actually learn how to use it.

[anarchist]

SR540Beaver,

 

I wonder if using a GPS is like using four wheel drive...you just manage to get stuck in rougher places....

 

Really, while I love playing with my GPS-a great pedometer...(BTW, there is a great protractor -$6-7.00, for converting as well as a plotter 'bout $53.00 for the seriously "ill"), I would never hit the woods without my two compasses, watch...and a map (if I was in real "unknown" territory....do I really want to trust the energizer bunnie ??? don't think so....

 

We have used it to plot river courses and campsite locations for future river runners and we always do this with two different model GPS's to be sure we are within a reasonable range...sometimes there is a significant difference (usually due to number of satelite "hits" at the time...). And truthfully I just always worry that the little gremlins running around inside the darn thing may just have it out for me on a given day....

 

anarchist

 

[kenk]

I'm not sure how GPS-bashing came into popular culture, but it is unfortunately there. I think it has something to do with the batteries.

 

GPS's do one thing - they tell you where you currently are, and they do that remarkably well considering the size of the Earth and the technologies involved (though they give VERY accurate time too). Today the accuracy is usually accurate enough to get you within a baseball's throw. Amazing.

 

Yes, batteries can run out and electronics can fail, but today's GPS's are extremely reliable and extra batteries are easy to carry along. Smart GPS users don't leave the units on all the time. Instead they turn them on occasionally to assess current position and obtain a bearing and then use a compass to follow the bearing, so batteries can last a very very long time.

 

Using waypoints, they can also tell you where you've been, or they can be pre-loaded with places you might want to go (or at least know where they are). Knowing these bits of information, GPS's can tell you the direction from where you are to where you have been or want to go. Extend this to many waypoints and draw lines/shading around them and you have a GPS map that can show you where you are relative to nearby landmarks (key waypoints).

 

At typical walking speeds they do only a mediocre job of telling you current direction and speed. At faster speeds they do a pretty darn good job of telling direction and speed (based upon relative location/time going from where you were to where you are now).

 

Compasses, on the other hand, do a very good job of telling you directions, but that is all they do. They, by themselves, do absolutely nothing to tell you where you are or where you want to go.

 

Maps provide several ways of telling you where you are, but they require you to be able to distinguish some kinds of landmarks. Have you ever tried to find landmarks in the middle of a fairly dense forest? Good luck! Without landmarks - as is common in dense forests, seas/oceans, or deserts - a map does nothing to tell you direction or location.

 

I see these three tools: GPS, compass, and map, as each being essential tools to modern navigation. All have weakness, all have strengths, and none can really be used alone.

 

GPS & Compass - It is pretty easy for most to take a GPS bearing and use it with a compass. This is what I do most of the time. It is usually unwise to rely on a compass to know your current direction - at least while walking. If you don't know the coordinates of your destination, your are stuck - neither the GPS nor the compass will help.

 

GPS & Map - GPS's and Maps talk to each other using coordinates. These days the preferred coordinate system for working with GPS and maps seems to be UTM coordinates. Failure to understand how to use UTM coordinates makes it very difficult to relate GPS informatioin to Map information - and vise versa. If you know how to use UTM coordinates, you can take your current location from the GPS and readily transfer that information to a map. You can also take a coordinate from the map and create a waypoint in the GPS. Its all done with coordinates. If you don't know which way is North (or south or ...) - this all falls apart - the GPS and Map won't help.

 

Map & Compass - This is the combination that Scouting has been teaching for years. Use the compass to orient the map, assess your current position from landmarks (either purely visually or by triangulation), determine the bearing needed to go from where you are to where you want to go, and then follow the bearing. If you don't have landmarks, you don't know where you currently are - and this too falls apart.

 

Learn to use all three well - and more importantly how to use them with each other - and you have a powerful combination of navigation tools.

[SR540Beaver]

Amen! Sho-nuff! Preach on Brother Kenk.

[kenk]

Here is a link to some nice free beginner's guides in from Garmin (they make GPS's) that can be downloaded:

 

http://www.garmin.com/aboutGPS/manual.html