+Team Wood! Posted October 23, 2010 Share Posted October 23, 2010 I've only found about 40 caches since I started Geocaching early this year so I still consider myself a newbie, however, with the help of my little ones I would like to go ahead and try to hide my first cache. I've bought some nice ammo containers, printed out good log books, and filled them with some nice trade items. So I'm ready to hide, but I want to ensure once I post the location is that the coords are as accurate as possible. There is nothing more frustrating than looking for a cache when the coords are 40 feet off and I wouldn't want to subject others to that. Anyway, I typically use a Blackberry Bold for Geocaching and I just bought a Garmin 60CSX. What I never expected was that the Blackberry seems to be every bit as accurate as the 60CSX. I've actually found on a few occasions the Blackberry will put me closer to the cache given its nice "radar" function with Geocache Navigator. So I did a few tests with both devices, marked the waypoints, and then put them in to Google Maps. What I found was that the coords both devices registered weren't all that accurate. They seem to do a better job of locating rather than actually returning your accurate location. Ultimately, I'm starting to wonder whether it might be more accurate to use Google Maps to obtain the coords if I can see the location from the satellite images. I tried a test doing this and it seemed to work very well, but since I know there are plenty of ohers on the forum with a great deal of experience doing this I thought I would ask what you thought. Is there any one of school of thought on how to do this to try and offer the geocaching community the most accurate and precise coords possible? Quote Link to comment
+Team Wood! Posted October 23, 2010 Author Share Posted October 23, 2010 I did just read some information around averaging waypoints so I need to try that. I guess my original question still stands though. Would Google's coords be just as accurate? They seem pretty close to me so far. Quote Link to comment
+ecanderson Posted October 23, 2010 Share Posted October 23, 2010 I did just read some information around averaging waypoints so I need to try that. I guess my original question still stands though. Would Google's coords be just as accurate? They seem pretty close to me so far. Google's coordinates MIGHT be accurate. They have improved greatly over the years. That said, they might NOT. Use your 60Csx and use the waypoint averaging function. Be sure you've first had it turned on long enough to give you the best possible EPE (error radius) reading that it will be able to achieve in the cache location. This will give you a better reading than taking a single "flash" waypoint for the location. It doesn't even hurt to do it at a couple of different times in a day just to be sure, especially if you're under heavy tree cover. After the fact, there's nothing wrong with using Google to sanity check the numbers you recorded -- just to be sure you didn't fat finger anything. I tend to do that after a hide just to be sure. Made a silly mistake once -- never again. Quote Link to comment
+bcblues Posted October 24, 2010 Share Posted October 24, 2010 Another way is to just record a few different coord measurements. While at GZ, write down the coords. Then, walk away at lewast 50 feet and back to the same GZ, write down the coords (they should be really close). Then walk off in a different direction 50 feet and back, repeat. You will find that most are the same, with perhaps one or two different ones. I just use the "same" ones. Then I go home and verify with Google Earth. The Google Earth coords are really pretty accurate in my stomping grounds. I HAVE used a survey grade Trimble unit to verify the locations of a few of my caches (not that I have placed very many), and the results with my 62s are accurate to the decimal places GC.com uses, so it is clearly overkill. Averaging waypoints is a time consuming venture, unless you have an absolutely unobstructed view of the sky and/or lots of patience. Quote Link to comment
+ecanderson Posted October 24, 2010 Share Posted October 24, 2010 Another way is to just record a few different coord measurements. While at GZ, write down the coords. Then, walk away at lewast 50 feet and back to the same GZ, write down the coords (they should be really close). Then walk off in a different direction 50 feet and back, repeat. You will find that most are the same, with perhaps one or two different ones. I just use the "same" ones. ... Averaging waypoints is a time consuming venture, unless you have an absolutely unobstructed view of the sky and/or lots of patience. I don't think that using my Oregon's waypoint averaging function would take any longer than what you're describing above. Quote Link to comment
+ventura_kids Posted October 24, 2010 Share Posted October 24, 2010 Take a reading.... walk away.... use that reading to see how close you can come to the cache. That's it. If you are close.... use those numbers. Quote Link to comment
+BlueDeuce Posted October 24, 2010 Share Posted October 24, 2010 Averaging just confirms that the accuracy is just a big circle, centered on whatever, on any given day. Take two or three marks. Walk away and do a GOTO and see which one does the best. That's what it is going to be like for everyone else. If there's tree cover, cliff walls, power lines, you might want to do readings under different weather conditions. For some reason I find cloud cover to do the best. Doesn't seem to be that way for others. Quote Link to comment
+dfx Posted October 24, 2010 Share Posted October 24, 2010 Averaging waypoints is a time consuming venture, unless you have an absolutely unobstructed view of the sky ... i'd say it's exactly the opposite way around. if you have an unobstructed view of the sky, your chance of getting very good coordinates with a single reading are already very high. but not so much when you're under tree cover, in a valley, etc. Quote Link to comment
+TheRedArmy Posted October 24, 2010 Share Posted October 24, 2010 your GPS can be exact, i mean exact, 0M accuracy and used by the miliary, but if they cache owner took bad co-ordinates when he hid it, it won't mean squat. find GZ, where you want to hide the cache, take an average for a minute or so. walk away, turn your GPS off, do it again. do a couple of test runs over the course of a day or 2 and see what you get. if 3 of the 4 times, you always get the same co-ordinates, then use those. like i said, even if you average your waypoint and are 100% sure you have perfect co-ordinates, it doesn't mean someone one be out 8-9m or more when they go to find it. it all depends on the GPS being used and the satellites etc. Quote Link to comment
GPS-Hermit Posted November 2, 2010 Share Posted November 2, 2010 (edited) Never rush a hide - if you don't have time - don't hide it! Make sure your GPS has a low accuracy level, EPE or ACCURACY - Set it on the cache and leave it alone keep looking at the accuracy figure to see if it stays low and stable or if it jumps all over the place. If stable great, if not you got work to do. If not stable or it just stays higher than you think it should, turn it off and back on again and let it sit. a reboot will sometimes achieve a better result! If stable (jumping 3 for 4 feet) - mark it! If not average it 100 times (takes 2 minutes of your precious time) Now walk away 100 feet, turn the GPS off then back on in a minute or so. Now do a GOTO to and see how it does. If close after 3 or 4 tries, from different directions, of this, you are good to go - report those co-ords. However, if you are having trouble, try and see what the problem is and decide if this is a good location for a cache. Rock does wierd stuff to signals. If you are on a ridge WAAS may help or hinder the signal. Try with WAAS off to see if it gets better - if so mention that in the cache listing. You can use the Cache description to help the finders get the cache. Easy to create a line between two fixed points and tell finders to search that line of sight. Like between a phone pole and a car size rock. Strive but don't worry about perfect co-ords - up the rating and let them look a little. But if the location is poor for a signal after a significant effort, consider another location. I do recommend coming back on a different day to see what happens and if any big difference is present, then deal with it in some effective way. Cachers just need to find the cache and have a ball being out there. Choose a great location and create a way to find it. Co-ords are nice, but not the only way to help find it. Edited November 2, 2010 by GPS-Hermit Quote Link to comment
+scuba_2 Posted November 4, 2010 Share Posted November 4, 2010 I check my coords on. http://www.opencaching.org.uk you have to register its free then login click cachemap3 on left hand side ,this brings up a map move the cross over the map and it gives a very accurate lat long read out. Quote Link to comment
+DWHeadstone Posted November 4, 2010 Share Posted November 4, 2010 Has anyone used the android free app called GPS averaging ? When I use it with my HTC EVO it comes up + - 2 to 3 meters. DW Quote Link to comment
+dfx Posted November 4, 2010 Share Posted November 4, 2010 click cachemap3 on left hand side ,this brings up a map move the cross over the map and it gives a very accurate lat long read out. no it doesn't. it gives a very consistent coord reading, but you don't know how accurate it is. Has anyone used the android free app called GPS averaging ? When I use it with my HTC EVO it comes up + - 2 to 3 meters. hey, my oregon gets that without averaging! Quote Link to comment
+mark_ca Posted November 4, 2010 Share Posted November 4, 2010 Has anyone used the android free app called GPS averaging ? When I use it with my HTC EVO it comes up + - 2 to 3 meters. DW Yup, I use it and it works great on my Nexus One and G2. Quote Link to comment
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