UTM Grid or Lattitude/ Longitude

12:47 p.m. on May 31, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

About four years ago I bought my first GPS unit and have learned to use it fairly well. Up until that time I was strictly map & compass, I am glad I learned to use the compass first, it is a valuable skill to have. But I have to admit, after using a GPS, that knowing exactly where you are on the map is cool. That is as long as the GPS unit is working properly.

I mostly navigate using the UTM grid as do my backing buddies. But I'm curious to know what preference, if any, others have and why.

5:52 p.m. on May 31, 2008 (EDT)
26 reviewer rep
98 forum posts

I use UTM on both my GPS and the topo maps I print from National Geographic Topo. When I am planning a bushwack I print a plain topo map and on the back I print one with the UTM grid at 100 meters. A check of the UTM coords on the gps allows me to quickly locate my postion on the printed topo.

8:37 p.m. on May 31, 2008 (EDT)
110 reviewer rep
762 forum posts

For what it's worth: Almost ALL SAR teams use UTM. Whether using GPS or map & compass.

10:47 a.m. on June 1, 2008 (EDT)
110 reviewer rep
762 forum posts

These may be of interest:

http://www.dbartlett.com/

http://www.maptools.com/

Maptools has printable UTM grid corners to use with your paper map. Print them on transparency stock, and you're in business.

4:30 p.m. on June 1, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

Thanks for the links f klock, when I can't be in the woods I like to spend some of my time learning all I can.

5:28 p.m. on June 1, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

UTM was devised as a method of locating targets for artillery and mortar fire (and other targets during military combat). The thought was that this was a simplified system for the large number of draftees who had not finished high school and who had not taken high school math courses. Even this proved too hard for a large number of the draftees, so an even more simplified system called Military Grid Reference System (MGRS) was devised. An additional motivation was that the letters part of an MGRS coordinate could be altered for security purposes, while remaining easy for the average dogface to decode. (for f_klock - that's why S&R units use UTM - most training for S&R is done in the military and much S&R in the US is done by and/or in conjunction with National Guard units and CAP, which is closely involved with the military).

Legend has it that one can easily figure distances in UTM, because it is a "square" grid. Just take the difference in the Eastings and then the Northings between the two locations, apply the Pythagorean Theorem (huuunnnnhhh???!!!?!!?!) and you have the distance in meters (excuse me? We'uns Yanks use miles and yards!). And the "square root of the sum of the squares" for those who didn't take high school math?? Give me a break!

Plus add in the fact that it is Universal Transverse MERCATOR grid system, results in the N-S line being significantly off true north near the edges of the Zones (meaning the magnetic compass correction shifts with location in the zone), all adds up to a system that has lots of built-in errors (ok, most people can't read their compasses or their maps well enough tho know the difference).

Plus add in the large discontinuity in numbering at zone boundaries (one of which runs right down the major part of the Sierra where I spend a lot of time) and the significant angle between adjacent zones.

And add in the fact that that UTM is not applicable in northern Alaska/Canada/Greenland/Scandinavia/Russia (including Siberia) or in Antarctica (you have to switch to something called Universal Polar Stereographic - UPS - coordinates in those areas), and UTM is a real mess.

Lat/lon is the standard grid on printed maps for most of the world, with only two countries that I have direct experience with using something resembling a UTM grid (and both of those use a country-specific origin point, so coordinates in their system do not match the "standard" UTM grid. Lat/lon is designed to match the shape of the Earth and has no discontinuities. It does have 2 singular points at the North and South Poles, but this is negligible compared to the discontinuities at the 60 zone boundaries and the weirdities of the UPS. Besides, on the scale of a backpacker, white water enthusiast, backcountry skier, or long distance bicyclist, lat/lon is a rectangular grid. For figuring distance, a minute of latitude is just over a mile (1 nautical mile to be more precise), and a minute of longitude is about 3/4 mile in the lower 48 (half-mile in Alaska and Canada). Yes, the longitude minute of arc does get smaller in miles as you go away from the equator, but the change is not enough to worry about for the foot-powered traveller.

For the sailor or especially airplane pilot, you travel far enough to traverse multiple zones in a typical trip (except sailing on a lake or along a coastline, in which case you use coastal navigation techniques anyway). Thus the discontinuities across UTM zone boundaries are a real pain in the neck. So for airplane or boating use, lat/lon is the natural system for coordinates.

Actually, it does not matter what coordinate system you use - UTM or lat/lon or State Plane or Range-Township - the map you are using determines it for you. After all, it is just an address system, no harder than finding 1234 North Main Street (or in SLC Utah, 2350 East 3900 South). And there is no worry if you are using a GPSR - the machine does it for you.

Personally, I use lat/lon, because it is just so much easier. It's just numbers, after all, not even as hard as phone numbers.

By the way, if you want to really learn how to use map and compass (and GPSR), my annual navigation workshop at Clair Tappaan Lodge (Sierra Club Lodge at Donner Pass) is the last weekend of this month - look on the Sierra Club website under Lodges and Lodge Activities, weekend of June 27-29. There is geocaching in the area as well with some fun caches.

7:44 p.m. on June 1, 2008 (EDT)
3 reviewer rep
170 forum posts

lat/lon. Why? See above! And because that is all the Coast Guard uses and that is what I am used to.

7:46 p.m. on June 1, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

Thanks Bill S, I would have to say that many of my skills were taught to me by military guys who now backpack. Thus the reason I switched to the UTM after I got a GPS maybe.
I go on a lot of bushwacks once I reach a certain point on the trail, in an effort to walk a straight line to where I am going which is a section of trout water with no trail to it, or is hard to get to.
That's the idea anyway, I have been off a pretty good bit by the time I hit the stream a few times with just a map and compass. And I'm pretty sure there is nothing wrong with them, so it must be me. (ha) I always use to double check my location with an altimeter since the areas were contoured all to pieces, and I could fix my location on a contour line.

Then I bought my friends GPS and viola!! The UTM grid is the way I was shown how to use it and I have just never changed the settings on the unit. You tend to do what works for you when it is getting dark and you are alone.

I appreciate your info, I think I will print it out, that was a lot to take in at once.
I would like to take one of your courses but you are too far away ( I currently live on east coast ), I will visit the website though.

8:01 p.m. on June 1, 2008 (EDT)
26 reviewer rep
98 forum posts

I've found the UTM system to be both more convienent and accurate than the latitude-longitude system, at least for my wilderness adventures, with both map and compas and gps. Perhaps that is why the USGS uses it too.

[Edited by Dave: no self-referential blog links, please]

11:37 a.m. on June 2, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

nogods says -

Quote:

I've found the UTM system to be both more convienent and accurate than the latitude-longitude system

The accuracy for map, compass, and GPSR is inherent in the tool itself. It does not matter what coordinate system you are using. The accuracy standard for USGS maps (and NIST/NIMA/DMA), paper version, is 1/50 inch for positions (the diameter of the 5mm pencil lead in many mechanical pencils, which works out to 40 feet on a 1:24,000 or 1:25,000 map), and 1/2 contour interval (so, +/- 20 ft on a typical 40 foot contour interval). Note that this is only for surveyed points. The error can be greater for locations between surveyed points.

The error budget for the GPS (that is, the complete Navstar Global Positioning System) for "non-authorized receivers" (such as consumer units) is 10 meters (2 sigma, the 95% level). This assumes an ideal distribution of the satellites being received. With WAAS, this goes down to 3 meters (about 10 feet), no matter what coordinate system you have selected. However, if you don't have an ideal distribution (due to canyon/canopy effects or simply what satellites are visible), the error can climb, and during increased solar activity it can climb as well (keep in mind that I was one of the authors of the system spec when I was working on the GPS). Once the L5 signal is available on the majority of active satellites (only 1 right now) or Block III is available (2015 or later), the "non-authorized" accuracy will get down to the meter level.

One caveat - some of the less expensive consumer pocket GPSRs display only to the nearest 0.0001 degree in the lat/lon decimal degree mode, which is 36 feet. Most display to 0.001 arc minute in the degree and decimal minute mode, which is 6 feet, which appears to be 6 times more "accurate". and to the nearest 1m in UTM. Actually, this is precision, not accuracy. Just because the display shows more digits does not mean your position has been determined more accurately. The accuracy is still no better than 10 meters (3 meters with WAAS), and usually worse because of various other effects.

3:53 p.m. on June 2, 2008 (EDT)
26 reviewer rep
98 forum posts

For the great majority of hikers and backpackers I think UTM is more convenient and workable, which ultimately leads to it being more useful and therefore more accurate as a practical matter.

I once ask a store clerk the price of the apples that were unmarked. He went into a long dissertation about how the price of things is determined by market forces but because of price supports, anti-trust laws, and other government infection of market forces, including land regulation, farming incentives, and transportation infrastructure, the price did not truly represent a simple supply and demand determined outcome. Turns out he was an economics student.

All I needed to know was the price of the damn apples. A simple sign stating "apples 25 cents each" would have been more useful than all the esoteric knowledge he sprayed at me. He may have been technically correct, but he was practically useless.

Hikers and backpackers don’t need survey accuracy to get from point A to point B and back again. They need something that they can understand and work with if the need arises. I think UTM fills that need better than any of the other systems.

4:49 p.m. on June 2, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

nogods said -

Quote:

Hikers and backpackers don’t need survey accuracy to get from point A to point B and back again.

Obviously. And since the accuracy of all consumer GPSRs is the same, it does not matter what coordinate system you have it set to. Nor does a hiker or backpacker need a coordinate system to use a map (assuming that s/he knows how to use a map properly). The only use for a coordinate system with a GPSR is to enter locations for which the only information is someone giving you the numbers. If you use a computer-based map program or trip planning service, the computer does it all for you, and you don't need to know anything about any coordinate system.

All you need to do is point at the map on the screen and click the mouse. If you follow roads, the computer will pick the route for you. For hiking, you just trace the trail (some programs will do this for you, too). Then you let the computer load the destination and route for you. Since the computer and the GPSR do all the figuring for you, it does not matter in the slightest what coordinate system you use. The GPSR will tell you how far and which direction to go.

Some people in the field want to locate their position on the map from the GPS-derived coordinates. This is easily done with either lat/lon or UTM using the tick marks printed along the neat lines (just be sure you look in the lower left corner to make sure your GPSR is set to the same datum as the map - otherwise you can be off by more than a football field length). Or use a map you printed out from NatGeo's Topo! with a lat/lon or UTM grid (Topo will do either).

By the way, USGS prints their maps laid out to lat/lon (lat/lon lines form the "neat lines", and tick marks and intersections on the map). They also print the coordinate tick marks for state plane, range/township (along with the range/township boundary lines), and UTM, plus sometimes (but not always) a 1 km UTM grid. So you can choose any of those coordinate systems that you wish to use.

With NatGeo's Topo!, you can print either a lat/lon grid or UTM grid overlay at whatever spacing you wish - 1 minute, 0.1 minute, 1 km (sometimes on the scanned map anyway), 100 meters, 50 meters. Again, it does not matter which coordinate system you want to use.

6:13 p.m. on June 2, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

....and then sometimes.....I just follow my dog!

6:46 p.m. on June 2, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

Dogs are often better navigators than humans. And they don' need no stinkin' coordinate systems, electronic widgets, maps, or compasses. They just follow their noses.

10:28 p.m. on June 2, 2008 (EDT)
26 reviewer rep
98 forum posts

last time I followed my dog it was tracking a skunk.

11:27 p.m. on June 2, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

My dog is pretty good at "in and out" or 180 type navigation especially if we have been there before. If we get lost its my fault and we just call it a loop.
Also I have a question about my compass, I have a Suunto MC-1G and
after leaving it in a hot truck all day it now has a wonderful little air bubble. Anyone know any tricks?
I have not contacted Suunto yet, just thought I would ask.
(I've already tried the freezer)

One other thing, an old timer once told me, jokingly, "Being lost is no time to practice that leave no trace stuff!"

11:13 a.m. on June 3, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

Only dependable "trick" I know for the bubbles in compasses is contact Suunto, Brunton (Silva Sweden's US subsidiary), or Johnson Worldwide (the US owners of the Silva trademark, put on compasses made by Suunto - oh, wait, maybe JWA has traded off "Silva", along with many of their other brands), get an RMA, and have them fix or replace it. Bubbles often appear when you take compasses to high altitude, but those shrink or disappear when you go back down to lower altitude. And bubbles often appear as compasses age.

Or, just bite the bullet if the bubble is large enough to interfere with the needle's operation and buy a new compass.

Brunton's take on it is here - http://www.brunton.com/faq.php?faq_id=53&faq_cat_selected=Compass In other words, cold produces the bubble most often, as does much overheating.

You could try this approach - http://www.adventuresportsonline.com/navigationcompass.htm

or this - http://www.scubaboard.com/forums/aeris/168627-compass-bubble.html

I won't recommend any tricks for the bubbles because all the ones I have been told or read about (a) didn't work, (b) were very temporary, or (c) ended up destroying the compass. That includes 2 methods I got from a compass manufacturer. That is, except for the ones for aircraft compasses, which are designed to have the fluid refilled. Most hiking compasses have the capsule sealed after being filled with the fluid (I have a very old Silva that has no fluid - it uses eddy currents induced in the aluminum bezel to do the damping).

The fluid in the compass usually is kerosene (usually "white" deodorized kerosene, specially prepared for compasses). Barb confirmed this once in an orienteering event when she fell on her compass and cracked the capsule - except that the kerosene wasn't all that much "deodorized". It was an expensive, specialized orienteering compass, too. Sometimes it is mineral spirits, and isopropyl alcohol has also been used.

11:28 p.m. on June 3, 2008 (EDT)
0 reviewer rep
84 forum posts

UTM Grid or Latitude/Longitude

Bill S (Old Grey Bearded One), nogods, and Trouthunter have all added some interesting points here whether they knew it at the time or not.

I would like to thank Bill S for sharing his knowledge about GPS with us. He has done so in the past and again here. I for one like as much information as I can get so that when I need to make those important decisions I can with confidence.

Nogods – “I think UTM fills that need better than any other systems”
I am sorry to hear about your dog and the skunk. Personally I have found that the UTM system works well to a point. If you want to return to a special point it can work, if you can call in SAR tecs, great. Keep in mind the UTM system only creates location points and the system only has meaning if the map/GPS user knows how to use the system.

Trouthunter – “Old timer joking - Being lost is no time to practice that leave no trace stuff” Whow.

The first time I used a GPS on a hike, the settings were to Latitude and Longtitude. I had borrowed the unit from a co-worker without learning how to use the thing. On land I found the Lat and Long to be very difficult to use with a Topo map as I did not have a large straight edge to mark off the co-ordinates quickly. I think that that is the appeal of the GPS with a map function. You can find your location quickly.


For the most part I like to study a Topo Map before I go out into the field. Roads, Bridges, water ways, steep hills, stuff like that.

I try to navigate with my head up, eyes open, ears tuned to local sounds, and brain engaged. I do like to have a Topo map, compass and horrors a GPS. I will also some times carry other maps of the area, such as forestry maps, historical maps, brochures, ect. I try to look around when I am traveling as well as checking my back trail as often as I remember. I try to take note of physical features I encounter. In other word I try to read the land. Why? I may loose all my modern stuff, it may not mate up with word of mouth information, the maps may not be up to date. Also I may pass this way again at a later date without all the stuff.

I had bought a government issue Topo map years ago, latest issue to boot. I showed it to a co-worker who hunted in the area and he pointed out some areas that the conditions had changed. Main logging roads that were no longer navigatable, bridges that weren’t there any more. Just a few months ago I looked at the latest issue for this map. Still no updates to this map years after I had bought my map.

In future will I get lost? Maybe, will it bother me? Not as much as it would have in the past.

11:22 a.m. on June 4, 2008 (EDT)
0 reviewer rep
171 forum posts

Two weeks ago I used a 1987 USGS topo map for a weekend excursion. I expected there to be some inaccuracies, and there were: new 4X4 and motorsports trails added to the 2 old logging roads shown on the map made it difficult to determine exactly where were when we started the hike. However, after leaving the roads, climbing some hills, and following a river we were fairly certain we knew where we were. We confirmed our position when we sighted, through binoculars, a ski lift six miles north of our position. We took a bearing on its position and plotted that on the map. We were at the bottom of the quadrant, which was lucky because otherwise the ski lift would have been in the next quadrant.

The point is that we had no gps but were able to locate our position quite accurately simply by using the compass and reading the topography shown on the map, without lat/lon or UTM.

It doesn't always work out so well, but it's always pleasing when it does. Of course, I still ski on wood, so I'm easy to please.

11:37 a.m. on June 4, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

rexim, my latest greatest tele skis have a wood core. Does that count as wood skis (fat, lots of sidecut)?

redpatch5, exactly the way wandering through the woods and hills should be done. And exactly the kind of thing I teach in my land-nav workshops. Gee, I could always use an assistant instructor. You gonna be at Donner Pass last weekend this month, by chance (no pay, just fun and meet interesting people)?

3:19 p.m. on June 4, 2008 (EDT)
0 reviewer rep
171 forum posts

Bill, I'm not a total Luddite, so I'll count your wood-core tele skis.

7:03 p.m. on June 4, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

I tend to put a lot of effort into planning my trips, I give all my gear the once over, double check my supplies, and study my topo extensively. I try to study the contour lines especially, because you can't just walk a straight line in the mountains, as I'm sure you all know. The FORK MOUNTAIN TRAIL in northwest South Carolina is ten miles of almost level hiking through the many ridges, coves and ravines that are found just below the Blue Ridge Escarpment.
This was accomplished because someone payed attention to the lay of the land instead of just marking waypoints. As redpatch5 pointed out! If you marked this hike as a straight line on your topo, and tried to follow it, you would of course work yourself to death. I know most of you already know this. But a lot of people just read a book and "head out".
I am astounded by the number of people out hiking that can't even follow a three foot wide trail with orange blaze. I certainly don't mind reassuring hikers that they are going the right way, and I am always glad to help out in any way I can. But I worry when I see people with a compass hanging around their neck, a map in their hand, and want directions to the "primitive camping area".
My point is that people need to stick with an experienced group or hiking club and pick up some basic skills before striking out on their own. Mastering the basics is way more important than being able to give someone all the technical data on a particular piece of gear.
Getting lost for the first time is what really woke me up, and made me realize that I did not have any real skill I could apply to the situation and had also left my LAND NAVIGATION HANDBOOK at HOME!!
My thanks to the nice older couple who told me how to get to the "primitive camping area" some 24 yrs. ago.

9:10 p.m. on June 4, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

Thanks Bill S, for the info on air bubbles in compasses. I have never had that happen before, and it has been over a year so I guess it is not going to be self correcting.
I have already replaced it with the same model a few months ago. It was just disappointing since the compass was only two years old. I feel like the only way to get a return on your gear is to take good care of it and make it last.
I'm not very big on buying the latest and greatest gear when mine works fine.
I doubt that I have to worry about getting air bubbles from altitude here in the appalachians, highest peak is Clingmans Dome at 6000' and some change.
I have seen a few guys from out west come here and laugh at our "little" mountains, only to discover that the challenge here is not altitude, it is however very nasty storms, flash floods, tornadoes, poisonous plants galore, lots of loose rock/soil and so on.
And some people come here from dry barren areas only to discover that they are allergic to all the pollen we have almost year round.
I can assure you it is hard to navigate with your eyes swollen shut! I know!
But I digress, thanks again for the info and the links, they were helpful.

7:18 p.m. on June 5, 2008 (EDT)
0 reviewer rep
84 forum posts

This is for Bill S OGBO - The Land Nav workshop would be a great way to explore the area, with or without a map. Thanks for the invite. I am sorry I wont be in the area any time soon, Still so many places here on Vancouver Island to explore. Good luck with the workshop. Which way is Nord??

7:40 p.m. on June 5, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

Quote:

Which way is Nord??

At your back, if you are facing Sud, or your right hand, if you are facing Oueste. Or if you are at the South Pole, "any which way".

8:58 a.m. on June 6, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

Hey Bill S, Would you recommend an up to date navigation book. I would like something comprehensive. I already have the Sierra Clubs Land Navigation Handbook by W.S. Kals.
Also I have been using Google Earth to help me plan my trips. The tilt feature is a big help in reading the topo. But I'm wondering if there is something better out there, more tailored to this specific task.

Thanks

12:45 p.m. on June 6, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

There are a number of good books. The NOLS and Seattle Mountaineers Wilderness Navigation books are fairly easy to find and very good. Dave Seidman's Essential Wilderness Navigator is excellent, but may be hard to find now. Outward Bound's Map & Compass Handbook is another. Bjorn Kjellstrom's classic book is excellent for compass, if you can find it (the Kjellstrom brothers invented the "Silva System" and designed the original baseplate compass. They founded the Silva company in Sweden, which is still one of the two biggest compass and survey instrument companies in the world. Bjorn came to the US in the 1950s, and passed away a few years ago). All of these are better than Kals' book, in my opinion.

But the best way to learn is just get out there and do it. Look on the US Orienteering Federation website and find a club near you (they have links to Canadian clubs as well, plus the International Orienteering Federation). Participating in a few orienteering meets will teach you a lot about reading the terrain and the proper way to use a map and compass (clue - compass is not used very much for actual navigation). Most clubs have beginner and intermediate workshops at their meets. Two weeks from now, there is a full weekend of orienteering in the Lake Tahoe area, and a month or so from now there is a full week of orienteering in the Wyoming/Colorado area - a great way to really learn, albeit intensive.

4:25 p.m. on June 6, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

Thank for the info Bill S.
I have the NOLS Wilderness Guide, have read it several times.
So I'll probably stick with them and get their NAV book.
I was also wondering if there are any computer programs better suited to wilderness travel than Google Earth in terms of letting you see terrain from a birds eye view. Maybe that is a bit unorthodox, but I have found it helps me learn to read the topos better.
I like to plot my course on the map before I leave the house. The established trails don't generally take me to the best fishing spots. Fishermans trails only take you to places that see a lot of fishing pressure.
The closest orienteering club I could get to is in N.C. but I will get in touch with them.
I currently live in Charleston S.C. and it is a five hour drive to get to the mountains, but I still do it!
And always will!

7:44 p.m. on June 6, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

National Geographic's Topo! program and Delorme's TopoUSA simulate 3D views by using USGS DEM files and draping the map over a terrain model they generate from the DEM files (Digital Elevation Model = DEM). This is not as good as comparing a photograph to the topographic map, but then, Google Earth's approach is to drape their aerial and satellite photos over a terrain model that comes from the same USGS DEM files. You can do "flythroughs" with them, as well.

Hmmm, actually I suppose very few people realize that Google Earth's 3D images are not really 3D photos, but use the simulated 3D.

There are some amusing aerial photos available through Google Earth of cities, where they make a mosaic, just as with Google Earth's regular images, but using images taken from closer to the ground. At some of the boundaries in cities where there are very tall buildings (NYC, Chicago, downtown San Francisco), you get these weird perspectives where the buildings "lean" in opposite directions on opposite sides of the street - like someone might draw the first time they have a perspective drawing exercise in art class.

There is a website that I will try to find that has a comparison of various locations to the topo map. I made up a set of such images that I use in my land-nav workshops. These are static, of course, where the 3D terrain models with Google Earth and Topo! can be viewed from multiple angles and zoom in and out.

5:47 p.m. on June 7, 2008 (EDT)
MODERATOR REVIEW CORPS
968 reviewer rep
3,470 forum posts

I have not tried Nat Geo's Topo! I know that in some ways I am behind the times. I still mail order my 7 1/2 maps off the state map supplied to me by the USGS 15 years ago.
I have seen the leaning buildings!

2:57 a.m. on June 10, 2008 (EDT)
0 reviewer rep
5 forum posts

I was in the military, think the utm was used because of NATO. :)

3:02 a.m. on June 10, 2008 (EDT)
0 reviewer rep
5 forum posts

Has anybody ever used Lowrance gps products? I have an ifinder, and it has many options on it. The unit I believe, can display utm cordinates. What is the best gps? Or if we have a map, I guess whats the most light?

12:36 p.m. on June 10, 2008 (EDT)
TOP 10 REVIEWER REVIEW CORPS
2,329 reviewer rep
5,251 forum posts

Lowrance makes good units, though they aren't very popular. Partly this is because they are fairly heavy, something close to twice as heavy as Magellan, Garmin, or Delorme units with similar features. I have liked the Lowrance units I have used, except for their weight. Their air and marine units are very good.

All pocket/backpacking GPSRs made in the past 5 years or so have a wide range of coordinate choices and datum choices (the ones for your car only allow WGS84/NAD83 for datum, and few have a choice of coordinate system - if they even let you see the coordinates, much less let you enter the coordinates).

Best GPSR? That is 90% user preference (and how hard the sales person pushes). User interface, size, and weight make a huge difference to most people. Some people even pick based on the color of the unit (most companies use different colors for their different versions within a particular group of units - for example, Garmin's basic eTrex is "the yellow eTrex"). A lot of the sales people used to push "The Garmin Interface" as being the most user friendly - except that Garmin has at least 4 different arrangements of the buttons and display and every model has a different menu order and what is displayed on each of the screen pages. A lot of people really like the Magellan interfaces and button arrangements on their various series.

Lightest weight comes at the cost of less features. The very lightest are the wrist-top units from Suunto, with the Garmin wrist-tops being next lightest. But these all are very limited in their displays. The next lightest are Garmin's eTrex series and Magellan's eXplorist series (which are pretty much all discontinued - basic rule of electronics is, after all, complete new lineup at least once a year). Within these two series, the very lightest are very basic units. If you want more capability, you get a heavier unit, though the size is close to the same throughout each series. But note, all consumer GPSRs have the same accuracy these days. This is a result of the competition among the chipset makers pushing to the limit of what is allowed by design of the system (Ground Control Segment and Space Segment - the satellites). All have an error budget of about 10 meters without WAAS available and 3 meters with WAAS assistance (almost all units have WAAS capability these days), with a clear view of the whole sky (no canopy, no canyons natural or man-made).

July 25, 2014
Quick Reply

Please sign in to reply

 
More Topics
This forum: Older: Cold weather stream crossings Newer: Bears are sometimes problems not just for campers
All forums: Older: TNF vintage packs Newer: California Backpacking In Oct/Nov