+Dread_Pirate_Bruce Posted May 14, 2008 Share Posted May 14, 2008 When I hide a cache, I record its coords with my GPS. However, before I submit it for publication, I confirm the coords with FlashEarth.com or one of the similar sites. If the coords from my GPS don't match those of FlashEarth, I figure out why. Does anyone else do that? I ask because I have recently looked for several caches that were 30 feet or so away from the posted coords and wondered if the owners had checked the coords first. Quote Link to comment
+joranda Posted May 14, 2008 Share Posted May 14, 2008 I have never had to do it like that. I just double check my coords before I head home. Quote Link to comment
+J-Way Posted May 14, 2008 Share Posted May 14, 2008 30-ft isn't a horrible error. You can get that much error easily just with atmospheric interference, not to mention heavy tree cover or tall buildings. A good receiver (SIRF-III) with a good view of the sky will easily get to within 10-ft, but 30-ft is reasonable under normal conditions. Your method of checking on a map would work great for identifying large errors (fat fingering a digit or two when typing the coordinates), but probably not for getting down to less than 30-ft. Quote Link to comment
+StarBrand Posted May 14, 2008 Share Posted May 14, 2008 The general accuracy of most handheld GPS units is 20 - 25 feet under most conditions. The best of the published maps out there have a general accuracy of 45 feet or more. Often less, sometimes more. I tend to trust my GPS over what any map interface says. But I do check. Quote Link to comment
TermiteHunter Posted May 14, 2008 Share Posted May 14, 2008 After an experience of EXTREME error in posted - vs - actual coordinates on a cache I placed I have begun to check the coordinates against Google maps prior to activating a cache. Most recently I did the reverse and located the cache with a map and then obtaining GPS coords for comparison. I have found that either my eyes are not as good as they used to be or my GPS accuracy is sometimes way off. I use an early Garmin ETrex but take several readings for an average (8-12) Quote Link to comment
+WRASTRO Posted May 14, 2008 Share Posted May 14, 2008 I use the maps just to make sure I didn't do something really stupid when I entered the coordinates. I have gone after several caches where there was an error made by the hider when they entered the coordinates which made for some interesting adventures. I don't want to be the next hider that makes that mistake so I check my coordinates on the maps. I am not looking for 30 feet. I am concerned about 100s of feet or more. Quote Link to comment
+briansnat Posted May 14, 2008 Share Posted May 14, 2008 I just click on the map links on the page to make sure the cache is on the right continent. When the Topozone link worked I'd also check that to make sure it was where I thought it was. I once submitted and had published a cache that was in NJ, but the page had it somewhere near the Canary Islands. After that I learned to check before I hit submit. Quote Link to comment
+WRASTRO Posted May 14, 2008 Share Posted May 14, 2008 I just click on the map links on the page to make sure the cache is on the right continent. When the Topozone link worked I'd also check that to make sure it was where I thought it was. I once submitted and had published a cache that was in NJ, but the page had it somewhere near the Canary Islands. After that I learned to check before I hit submit. That must have been before the vacation cache guidlines went into effect. Quote Link to comment
+El Diablo Posted May 14, 2008 Share Posted May 14, 2008 I once submitted and had published a cache that was in NJ, but the page had it somewhere near the Canary Islands. After that I learned to check before I hit submit. And I wasted 2 weeks and several thousands looking for that one. However the Canary Islands were beautiful. El Diablo Quote Link to comment
+ArcherDragoon Posted May 14, 2008 Share Posted May 14, 2008 When I hide a cache, I record its coords with my GPS. However, before I submit it for publication, I confirm the coords with FlashEarth.com or one of the similar sites. If the coords from my GPS don't match those of FlashEarth, I figure out why. Does anyone else do that? I ask because I have recently looked for several caches that were 30 feet or so away from the posted coords and wondered if the owners had checked the coords first. 30ft...really not that bad...personally, once I get within 30ft according to the GPS, I usually just put it away and try to think "Where would I hide a cache"... . . . Overall...30ft is pretty darn good for accuracy... . . . Checking coords...I do a quick look at the yahoo/google map to be sure I didn't record something wrong...but other then that, I trust the GPS numbers... Quote Link to comment
+Stargazer22 Posted May 14, 2008 Share Posted May 14, 2008 Yep, I always double check my coordinates on at least one map (usually Google Earth) before I submit just to make sure I am in the right neighborhood. But I wouldn't expect 30 foot accuracy on a map. Between GPSr error, and map errors, that's expecting too much. As long as it's showing up on the right side of the creek, road, etc... I know I am in the right ballpark. I trust my GPSr after that. Quote Link to comment
+sataraid1 Posted May 14, 2008 Share Posted May 14, 2008 I always check Google Earth just to see if I'm in the ballpark, but the GPS coordinates are the final word. Quote Link to comment
+edscott Posted May 14, 2008 Share Posted May 14, 2008 30-ft isn't a horrible error. You can get that much error easily just with atmospheric interference, not to mention heavy tree cover or tall buildings. A good receiver (SIRF-III) with a good view of the sky will easily get to within 10-ft, but 30-ft is reasonable under normal conditions. Your method of checking on a map would work great for identifying large errors (fat fingering a digit or two when typing the coordinates), but probably not for getting down to less than 30-ft. I find good aerial photos will get me within less than 30 feet of GZ. Those larger errors that get reported are not in the photo itself, but in the reading of that photo. There are exceptions of course when things on the ground have been altered since the photo was taken. You do need to know your photo source. Some sources are great in some parts of the world and off in others. It may take some research to find the best source for your area. Quote Link to comment
jrecon Posted May 16, 2008 Share Posted May 16, 2008 i only use a map.... so far my plotting is 250 meters off from the gps coords given. i search caches on google topo maps to check my plotting when i plot the coords given for the cache it's not even in the ball park!!!! my buddy uses a gps and it's spot on... but he hasnt plotted any yet... wondering if i'm missing a conversion somewhere???? at least my plotting errors are consistent............... Quote Link to comment
+Kiwi Nomad Posted May 16, 2008 Share Posted May 16, 2008 I use the maps just to make sure I didn't do something really stupid when I entered the coordinates. I have gone after several caches where there was an error made by the hider when they entered the coordinates which made for some interesting adventures. I don't want to be the next hider that makes that mistake so I check my coordinates on the maps. I am not looking for 30 feet. I am concerned about 100s of feet or more. Yeep thats why I use it too. Quote Link to comment
+TeamGumbo Posted May 16, 2008 Share Posted May 16, 2008 Yes, but with a totally fictitious map I made on posterboard back in 5th grade as part of an assignment on pirates. So far it has worked out quite well. Quote Link to comment
+paleolith Posted May 16, 2008 Share Posted May 16, 2008 30-ft isn't a horrible error. You can get that much error easily just with atmospheric interference, not to mention heavy tree cover or tall buildings.Yes, but that's the point. If you can improve the accuracy with another tool, you reduce the amount of error which finders have to deal with. Personally I would not trust most maps in the 30' range, but Google's aerial photos seem to be accurate enough that I'll make small corrections using them when features near the cache are sufficiently apparent. If it reduces the hider's error from 30' to 10', then it reduces the finder's search radius from 60' to 40'. Getting under about 10' is almost impossible, since GPSr units used for geocaching usually display a resolution of .001 minutes, and .001 minute of latitude is about 6'. Edward Quote Link to comment
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