+90%Angel Posted November 24, 2009 Posted November 24, 2009 Hi, I would like to know if you use the regular Waypoints of N 49 ____ W 121 ____ (example only) and which you find better, or more acurate? My Geo-friend uses only UTM's and swears by those Co-ords? I'd appreciate some feedback on this about which is better, if at all. I hope to get a GPS sometime in the next 6 months and would like to know the difference. Thanks Quote
+Tequila Posted November 24, 2009 Posted November 24, 2009 For geocaching, I use Lat/Long as everything is maintained in that format. Most puzzles resolve down to a Lat/Long solution. To translate Lat/Long to UTM would just add another step to the process and do nothing to affect accuracy. In the field, for multis, you would have to convert or switch profiles. For Search & Rescue, we use MGRS (a derivative of UTM). It has several benefits. First, when transmitting on the radio. it is always 8 digits. Second, before the use of GPS became prevalent, MGRS allowed you to quickly find a location on a paper topo map and to calculate distances. As for accuracy, assuming you use all of the UTM digits, there is no improvement in accuracy from one system to the other. Don't forget all GPS units have a positioning error built in. Commercial GPS units are not designed to find a penny in a hay field. For geocaching, the coordinates are designed to get you very close to the container. One of the nice things about the new Garmin units (Oregon) is that they implemented a "Profiles" concept where each profile has several configurable options including position format. To switch from a profile using Lat/Long to a profile using UTM / MGRS is two key strokes. Quote
+90%Angel Posted November 24, 2009 Author Posted November 24, 2009 For geocaching, I use Lat/Long as everything is maintained in that format. Most puzzles resolve down to a Lat/Long solution. To translate Lat/Long to UTM would just add another step to the process and do nothing to affect accuracy. In the field, for multis, you would have to convert or switch profiles. For Search & Rescue, we use MGRS (a derivative of UTM). It has several benefits. First, when transmitting on the radio. it is always 8 digits. Second, before the use of GPS became prevalent, MGRS allowed you to quickly find a location on a paper topo map and to calculate distances. As for accuracy, assuming you use all of the UTM digits, there is no improvement in accuracy from one system to the other. Don't forget all GPS units have a positioning error built in. Commercial GPS units are not designed to find a penny in a hay field. For geocaching, the coordinates are designed to get you very close to the container. One of the nice things about the new Garmin units (Oregon) is that they implemented a "Profiles" concept where each profile has several configurable options including position format. To switch from a profile using Lat/Long to a profile using UTM / MGRS is two key strokes. hmmm... interesting. Ok, I thought one system might be more accurate than the other. I've never used either, but my friend swears the UTM is the best way to go. I think when I finally do get a GPS I would use Lat/Long instead. Thanks for your input! Quote
+PDOP's Posted November 24, 2009 Posted November 24, 2009 For an explanation of UTM see A PRACTICAL GUIDE TO GPS - UTM (link) Quote
+Tequila Posted November 24, 2009 Posted November 24, 2009 For geocaching, I use Lat/Long as everything is maintained in that format. Most puzzles resolve down to a Lat/Long solution. To translate Lat/Long to UTM would just add another step to the process and do nothing to affect accuracy. In the field, for multis, you would have to convert or switch profiles. For Search & Rescue, we use MGRS (a derivative of UTM). It has several benefits. First, when transmitting on the radio. it is always 8 digits. Second, before the use of GPS became prevalent, MGRS allowed you to quickly find a location on a paper topo map and to calculate distances. As for accuracy, assuming you use all of the UTM digits, there is no improvement in accuracy from one system to the other. Don't forget all GPS units have a positioning error built in. Commercial GPS units are not designed to find a penny in a hay field. For geocaching, the coordinates are designed to get you very close to the container. One of the nice things about the new Garmin units (Oregon) is that they implemented a "Profiles" concept where each profile has several configurable options including position format. To switch from a profile using Lat/Long to a profile using UTM / MGRS is two key strokes. hmmm... interesting. Ok, I thought one system might be more accurate than the other. I've never used either, but my friend swears the UTM is the best way to go. I think when I finally do get a GPS I would use Lat/Long instead. Thanks for your input! UTM is "better" because you can measure distances much easier. As you further north or south the distances between lines of longitude get narrower and makes it impossible to measure distances by using simple math. Of course, GPS units and mapping software reduces that issue but in the field with just a topo map, UTM is great. Quote
+90%Angel Posted November 25, 2009 Author Posted November 25, 2009 For an explanation of UTM see A PRACTICAL GUIDE TO GPS - UTM (link) The link looks Great... lots of info there... thanks for sharing that! Quote
+Whistlen Posted November 25, 2009 Posted November 25, 2009 I use UTM and really enjoy it...that's for work stuff. Quote
7rxc Posted November 26, 2009 Posted November 26, 2009 The big advantage to using UTM with appropriate UTM maps is the presence of the printed gridwork. Trying to transfer Lat Long from the edges, especially in the field, is really awkward. Really tough on windy days. You can use the grid while partially folded up. Of course if you are digitally mapped and good to go it isn't all that important to use maps, but I recommend trying to have one available for the days the batteries go south... compass too!. Geocaching of course uses the DD MM.mmm display format, and WGS84 datum. You can on most GPSrs intended for field navigation, enter one format and change over to another with the press of a few buttons. One does have to watch that the one in use corresponds to what you need at the moment. Some of the automobile units seem to lack the ability to change though... there are multi outputs available on the cache pages if you click the alternative link. IF you don't have the change option... but I'm not sure that allows for datum change, but most that don't allow format change do seem to allow datum changes, but not all. Go figure... I think it's because the car type already have their own maps installed... or it is an older software version... not sure about that. Doug 7rxc Quote
+90%Angel Posted December 1, 2009 Author Posted December 1, 2009 The big advantage to using UTM with appropriate UTM maps is the presence of the printed gridwork. Trying to transfer Lat Long from the edges, especially in the field, is really awkward. Really tough on windy days. You can use the grid while partially folded up. Of course if you are digitally mapped and good to go it isn't all that important to use maps, but I recommend trying to have one available for the days the batteries go south... compass too!. Geocaching of course uses the DD MM.mmm display format, and WGS84 datum. You can on most GPSrs intended for field navigation, enter one format and change over to another with the press of a few buttons. One does have to watch that the one in use corresponds to what you need at the moment. Some of the automobile units seem to lack the ability to change though... there are multi outputs available on the cache pages if you click the alternative link. IF you don't have the change option... but I'm not sure that allows for datum change, but most that don't allow format change do seem to allow datum changes, but not all. Go figure... I think it's because the car type already have their own maps installed... or it is an older software version... not sure about that. Doug 7rxc hmmmm interesting... thanks for your input! I don't have a GPS yet, maybe Santa will bring me one! Happy Caching! Quote
+Landsharkz Posted December 2, 2009 Posted December 2, 2009 We have a LOT of puzzles nearby that are purely UTM - we start working on one and it becomes apparent pretty quick that it's not going to start with N49 or N48. I guess we're bilingual on this island when it comes to UTM and Lat Long :-). Quote
+Tequila Posted December 2, 2009 Posted December 2, 2009 We have a LOT of puzzles nearby that are purely UTM - we start working on one and it becomes apparent pretty quick that it's not going to start with N49 or N48. I guess we're bilingual on this island when it comes to UTM and Lat Long :-). Maybe a bunch of your cachers are SAR members. BC has a very impressive volunteer search and rescue community. Including a bloodhound. Quote
7rxc Posted December 2, 2009 Posted December 2, 2009 Maybe a bunch of your cachers are SAR members. BC has a very impressive volunteer search and rescue community. Including a bloodhound. You can count me in... Still need a FTF on a lost person, but I do well with digital cameras and Cellular Phones... I use whatever format the cache requires... my GPS along with many others converts easily amongst the formats... There are a lot of other SAR types around cacheing as well, you are correct... good practice for nav and gut instinct as to hides. Not to mention getting familiar with places people go to get 'missing'. You'll find a whole bunch of SAR types Stateside for sure, and probably anywhere else it exists... BTW I'm an ex-Ontarian from way back... coming back for a wedding/ birthday in the spring... hope to get a few Ontario caches amongst others then... Doug 7rxc Quote
+DENelson83 Posted December 10, 2009 Posted December 10, 2009 (edited) I use lat/lon, in the form HDDDMMSS.S. That's the coordinate format I've always used. I also enter coordinates into my GPSr in that format. Edited December 10, 2009 by DENelson83 Quote
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