U T M units -- the better way?

[Guest lost_soul]

I think UTM is a lot easier way to transfer points to and from utm maps.For hicking and hunting in the forest this is by far a better way than longatude and latitude.Anyone out there use these units? I would like to know if the U.S. has maps in this format, because anything published in the U.S. doesn't mention UTM.

 

Also I would like to get a download program for my Lowrance that uses UTM.

[Guest Rich in NEPA]

 

Lost_Soul, it is my understanding that all recent USGS topographic maps have the UTM grid lines preprinted on them. I have numerous PA-NY-NJ 1:24000-scale maps that have them. For the ones that don't have the UTM grid lines on them, I make my own. Using a 3' steel straight edge and a 0.25mm tubular tip plotter pen with permanent black ink, I draw the lines from one tick mark to the other across the map. Works great!

 

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~Rich in NEPA~

 

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? A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ?

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[Guest BLEdwardsJ]

I use UTM to seek without GPS. ALL of my USGS quads have them marked. At least to ones I buy here in Southern Utah. I have also made some transparent protractors to lay on the maps. I have them for 24,000 and 100,000 maps. I think UTM is a totaly functiional system, but I dont know how to set them into my garmin 38 so I use WGS 84 or NAD 27 datum. There is a link on all of the caches to get the UTM grids.

[Guest bacpac]

I use USGS DRG maps. They are free for some areas and the free view displays coordinates in UTM format. The map datum is NAD 27.

 

If your GPS does not match your map datum you will never be in the right spot. I set my GPS to WGS 84 hh mm.mmm ro record cache coordinates, but I hunt them with NAD 27 UTM format.

[Guest JAMCC47]

I swear by UTM's, I'm in the hills all summer long with the USFS and they give the best way to know where you are at, when I have to radio for assistance for some flatlander that should of stayed in the bar at the lodge.

If you have a topo program its good to put the grid lines at 500 mtr @ 1:24k and if you really want to get a close up look go to 250mtr @ 1:12 K and see what you can do with you utm ruler.

 

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JoseCanUSea

[Guest mrcpu]

n the principle of easting then northing so if I say to you meet me at 123 456 that means that on your map (we first must agree on using the same map!) you look across until you find the line 12 and up until you find 45 (these of course could really mean 612000 and 3245000).

 

You then go east 3/10ths of the way across the square and 6/10ths of the way up the square and there you are.

 

Now, a 4 digit grid ref is off course 1000 metres by 1000 metres. A 6 figure like the example above shows is 100x100 an 8 figure like 1234 5678 is 10x10 and a 10 figure is 1x1.

 

In the infantry a 6 figure was more then enough to get you to a landmark like a cross roads or a building. I was in a Mortar company and we used 8 and 10 figure for fire control. I've heard that artillery and guided missles used 12 to 16 figure!

 

 

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MrCpu

mrcpu@myrealbox.com

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[Guest Alan2]

quote:

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Originally posted by Rich in NEPA:

 

Lost_Soul, it is my understanding that all recent USGS topographic maps have the UTM grid lines preprinted on them. I have numerous PA-NY-NJ 1:24000-scale maps that have them. For the ones that don't have the UTM grid lines on them, I make my own. Using a 3' steel straight edge and a 0.25mm tubular tip plotter pen with permanent black ink, I draw the lines from one tick mark to the other across the map. Works great!

 

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I used both .1 and .05 acid free archival pens you can get in art supply stores. They're waterproof, disposable, single pigment. About $2.50 each. Available in different colors although I used black. Actually I found the .05 too fine as I was having trouble seeing it through a basemap compass to line up north lines although it's easily seen otherwise. The .1 mm seems better.

 

Alan

[Guest Rich in NEPA]

quote:

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Originally posted by Alan2:

I used both .1 and .05 acid free archival pens you can get in art supply stores.

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Alan, those pens sound like they'd be a pretty good option, and probably easier to find. What kind of tip do they have?

 

The only real advantage to the tubular-tip technical pens is that the lines are extremely uniform, even with varying pressure. I've found that felt-tipped pens flatten out in a short time, and ball-points seem too uneven, and the ink dries slowly and smears easily if you aren't careful.

 

In my case, I found a 0.1mm pen to be a bit too fine. I now have a 4/0 (0.18mm) Koh-I-Noor tech pen that I'm going to try.

 

In case anyone is interested, here's what I've measured (using a 100x magnifier with a O.001"/0.01mm reticle): USGS topos with printed UTM grid have fairly uniform lines averaging 0.12mm in width. The 0.25mm tech pen that I use lays down a very uniform line that is really only 0.2mm wide.

 

Bear in mind that (unless my math is messed up) on a 1:24000 scale map, a 0.1mm wide line subtends ~4.17 meters. My homemade UTM rulers have 0.1mm wide tick marks spaced for 10-meter intervals on the map. My guess is 10 meters is about the best you can resolve by eye under field conditions, anyway.

 

Cheers ...

 

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~Rich in NEPA~

 

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? A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ?

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[Guest Waterboy]

A comment on UTM system. If you do you this system please beware of its shortcoming, as well as its advantages. This is a set of 60 flat earth approximations use for navigation. A flat earth model is a good approximation in most conditions but not all. A problem may occur going from one flat surface (or zone) to another. GPS units compensate for the problems, but if you like doing your own mathematics, there may be problems.

 

The UTM zones that cover most of North America are listed below:

 

LONGITUDE ZONE

 

72 W to 66 W 19

78 W to 72 W 18

84 W to 78 W 17

90 W to 84 W 16

96 W to 90 W 15

102 W to 96 W 14

108 W to 102 W 13

114 W to 108 W 12

120 W to 114 W 11

126 W to 120 W 10

 

If your geocaching trip is entirely in one zone, no problem, everything works beautifully. A partial list of things to remember are:

 

1. UTM always works fine if you are only traveling in the North/South direction.

2. It works fine in the East/West direction except when you cross a zone. At this time the easting component will jump. (This jump does not occur at the equator.)

3. Your UTM or grid north direction is only the same as the true north if you are in the center of the zone. This would me at Long=W069º for zone 19, Long=W075º for zone 18, etc. This error is small. I have not seen the geocaching problem yet that this error makes significant.

4. The UTM system works best at the equator, and deteriorates the further you get from the equator.

5. As you get close to the poles UTM should not be used, however since the closest geocache to either pole is slightly less than 70º Latitude, this is not a problem yet.

 

To demonstrate the problem with UTM try this:

A. Get the UTM coordinates for N040º00.001?, W075º00.001? and for N039º59.999?, W074º99.999?. What is the difference in UTM northing and easting.

B. Now get the UTM coordinates for N040º00.001?, W078º00.001? and for N039º59.999?, W077º99.999?. What is the difference in UTM northing and easting.

 

An alternate demonstration would be to compare the easting lines on two adjacent USGS maps. One map just east of Long=W078º and one just west of Long=W078º. (Also compare the northing, where there should be no problem.)

 

I believe one of the biggest advantages of UTM is that it uses the simpler metric system instead of the miles, nautical miles, feet, inches British system.

[Guest Alan2]

rs easily if you aren't careful.

 

In my case, I found a 0.1mm pen to be a bit too fine. I now have a 4/0 (0.18mm) Koh-I-Noor tech pen that I'm going to try.

 

In case anyone is interested, here's what I've measured (using a 100x magnifier with a O.001"/0.01mm reticle): USGS topos with printed UTM grid have fairly uniform lines averaging 0.12mm in width. The 0.25mm tech pen that I use lays down a very uniform line that is really only 0.2mm wide.

 

Bear in mind that (unless my math is messed up) on a 1:24000 scale map, a 0.1mm wide line subtends ~4.17 meters. My homemade UTM rulers have 0.1mm wide tick marks spaced for 10-meter intervals on the map. My guess is 10 meters is about the best you can resolve by eye under field conditions, anyway.

 

Cheers ...

 

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I don't know what kind of tip but I've noticed no change in the width of the lines drawn after doing a number of quads. The ink does not smear.

Another trick I learned from a draftsman (before autocad computer programs) is that you rotate a pencil as you draw a line so the line width is uniform.

Alan

[Guest JamieZ]

quote:

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Originally posted by Alan2:

Another trick I learned from a draftsman (before autocad computer programs) is that you rotate a pencil as you draw a line so the line width is uniform.

Alan

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I learned that from my high school drafting teacher. I always figured everyone knew that until someone laughed at me once for turning my pencil while I made a line. That's when I realized that this was probably a dying technique. It works very well.

 

Jamie