Scout03 Posted October 30, 2003 Share Posted October 30, 2003 Can someone point to a place that explains how to take the coordinates from my GPS and find the spot on a standard USGS topo map? The topo map has UTM coordinates?? scout03 Quote Link to comment
+Renegade Knight Posted October 30, 2003 Share Posted October 30, 2003 The quickest way is to just convert your GPS to UTM. The GPS will do any translation you need and then you can find the spot directly. Quote Link to comment
+Warriorrider Posted October 30, 2003 Share Posted October 30, 2003 http://www.jeeep.com/details/coord/ This is an easy to use converter if you do not want to change the setup on your GPSr. Quote Link to comment
+Alan2 Posted October 31, 2003 Share Posted October 31, 2003 When you change the coordinate position to UTM in your GPS, you ought to change the Datum from WGS84 to NAD27. That is the Datum most USGS topos are setup in. It's not mandatory for only a general location orientation as you'll only be off 50-200 yards depending where in the USA you are. But you need to switch Datums for more accurate positioning. Do not forget to switch back to WGS84 and DD MM.MMM when entering coordinates from the cache site or your new waypoint locations will be inaccurate. Alan. Quote Link to comment
+Alan2 Posted October 31, 2003 Share Posted October 31, 2003 Here's an explanation of how to use UTM maps. Good luck. Don't get lost! Alan Quote Link to comment
Dan Vull Posted October 31, 2003 Share Posted October 31, 2003 A handy tool to use when plotting on a topo sheet using UTM is a see-thru mm scale. This translates your meters to mm and helps you drop them on the sheet. Quote Link to comment
+Blaidd-Drwg Posted October 31, 2003 Share Posted October 31, 2003 It's been a while since I purchased a USGS map, but the last ones I bought did not have the UTM grid system superimposed on them. Each map does however have tickmarks on the edge that would allow the owner to draw their own grid. The tickmarks would be labeled with small numbers. For the gridlines denoting northing, the numbers would be somewhere near the range of 33-40, while the numbers for the gridlines denoting easting would mostlikely be between 2 and 7. Once you have the gridlines drawn, it is a simple matter to follow the instructions from all the above. Enjoy Madog "Discover of America, ca 1169" You can't be a real country unless you have a beer and an airline - it helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Source: Frank Zappa Quote Link to comment
dsandbro Posted October 31, 2003 Share Posted October 31, 2003 clear plastic overlays with UTM ticks for various scale maps are available from many places. I think REI offers one (I didn't check). forestry-suppliers.com and benmeadows.com carry several types. Search for UTM. Others? =========================================================== "The time has come" the Walrus said "to speak of many things; of shoes and ships and sealing wax, of cabbages and Kings". Quote Link to comment
jimburns Posted October 31, 2003 Share Posted October 31, 2003 Another alternative, and I say this because I need some folks to try this tool out as it's fresh off the block, is here, http://www.technologydynamics.com/software/dtpt/math_geoconvert.html You'll find a temporary web page with a download link and some screenshots. In a nutshell, it's a comprehensive solution to many common questions. The highlights include, * Calculation of Lat/Lon format conversions as well as from Lat/Lon <--> UTM. * Calcs surface distance between points (accepts UTM or Lat/Lon) * Uses both great circle and small circle formula to calculate X and Y translations * Calculates small circle d/m/s distances for any specific latitude but also calculates an entire table in 5 degree increments I wrote the tool because of my own geocaching experiences and problems trying to out think folks on multi-caches when the instructions were too vague. How exactly does one subtract 48 from N 29° 39.880'? So my initial goal was to create a tool that played all the possibilities and let me see some of the magnitude of the possibilities. From there the rest just sort of naturally followed. One needs to adjust for latitude when figuring longitude adjustments, etc. The tool is freeware and I've tested it myself but I'm sure there's something here or there I've missed so any bug reports or descriptions of problems are appreciated. The tool is very self-explanatory and the UI is highly flexible. For example, most input boxes take lat/lon in any format, DDD, DMM, DMS and UTM. Any thoughts and feedback are much appreciated. /jim/pearland/tx Quote Link to comment
+GeoCraig Posted October 31, 2003 Share Posted October 31, 2003 Try Maptools.com at http://www.maptools.com/index.html They have a great site, including some free downloads of UTM overlays. Also some good explanations on how to use GPS and topo maps together. Quote Link to comment
Dan Vull Posted October 31, 2003 Share Posted October 31, 2003 Sorry I forgot not all USGS Quads are available in metric yet. Iswear if the US holds out just a little longer the rest of the world will see the error of going metric and come back to imperial. Three jeers for the foot. Quote Link to comment
+Blaidd-Drwg Posted October 31, 2003 Share Posted October 31, 2003 UTM Grids posted on USGS maps are always in meters. The normal grid square for a 1:50000 map is 1Km square Madog "Discover of America, ca 1169" You can't be a real country unless you have a beer and an airline - it helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Source: Frank Zappa Quote Link to comment
+WaldenRun Posted October 31, 2003 Share Posted October 31, 2003 quote:Originally posted by jimburns:Another alternative, and I say this because I need some folks to try this tool out as it's fresh off the block, is here, http://www.technologydynamics.com/software/dtpt/math_geoconvert.html Wow Jim, This looks REALLY useful for me. Since I don't use GPS, I often have a need to know distances and offsets from my plotted points. I'll be using this and providing feeback. -WR What doesn't kill me only makes me stronger. Quote Link to comment
+Alan2 Posted October 31, 2003 Share Posted October 31, 2003 National Geographic Topo which uses all the 24,000 scale USGS topo maps allow you to add the grid lines to the display and printout. You can set it up to the usual 1000 meter or anything else including mile intergers, 500 meters, etc. The grid lines can be dashed or solid in whatever color you select. You can also display lines in traditional DD MM SS position grid sections of 30 seconds or one minute or whatever instead of UTM. When printing any of the maps, the grid lines are tagged with their values. You also get scales in miles and meters, contour shading and the magnetic north offset so you can adjust you regular compass for true north. Of course can upload and download waypoints, route, tracks as well as creat your own tracks, show altitude reliefs, etc. However, the maps themselves cannot be loaded in to your GPS receiver. NG Topo is costly but a great product. Alan Quote Link to comment
Scout03 Posted October 31, 2003 Author Share Posted October 31, 2003 Hi everyone. . . Thanks for the help. I found a "tutorial" on UTM and map reading on the web today. I think I can do it. . . I'll do it for practice now a few times to see if I get it . . Scout03 Quote Link to comment
2oldfarts (the rockhounders) Posted October 31, 2003 Share Posted October 31, 2003 quote:Originally posted by Scout03:Can someone point to a place that explains how to take the coordinates from my GPS and find the spot on a standard USGS topo map? The topo map has UTM coordinates?? scout03 It's very easy to find GPSr coordinates on an USGS topo map. First look at the top right corner of the map and you will see the lat and long for the corner. Look at the bottom right corner of the map and you will see the lat and long for that corner. If the lat at the bottom corner is 40 degrees for instance the half way up the map on the right margin will be the number 30(minutes), a quarter of the way up will be the number 15(minutes), etc. The same applies for the longitude. If the right side is a whole degree then as you move left you find the minutes, 7.5, 15, 30, etc. All topo maps have these. It just take a little pratice and you can plot any set of coordinates in just a couple of minutes. once you recognize the numbers it's easy to find the minutes and 'eyeball' a line across the page for lat and long. Where the lines intersect is the point you're looking for. good luck John ******************************************************* It's hard to remember that your primary objective is to drain the swamp, when you're up to your a$$ in alligators. Quote Link to comment
2oldfarts (the rockhounders) Posted October 31, 2003 Share Posted October 31, 2003 I was in error when I mentioned in the above reply that half way up the side margin would be the number 30(minutes). It would be midway between the bottom right corner coordinate and the upper right coordinate. In other words if the bottom right is 40 degrees 0 minutes and the upper right is 40 degrees 30 minutes then half way up the margin will be 40 degrees 15 minutes. The map will only show the '15' at the half way point. 1/4 of the way up will show '7.5' and 3/4 of the way up will show '22.5'. Each corner shows the coordinates for that corner of the map. I had made the assumption that the map was a 1 degree x 2 degree size. Each map scale will be different but if you check the corners finding the point you want is very easy. John ******************************************************* It's hard to remember that your primary objective is to drain the swamp, when you're up to your a$$ in alligators. Quote Link to comment
+Alan2 Posted October 31, 2003 Share Posted October 31, 2003 Thanks for clearing that up! Quote Link to comment
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