How do I "average" a waypoint?

[Gabriel333]

I saw in the "Frequently asked questions" that the moderator said that averaging a position is poor way of getting a precise position. Well this is not the case if you use the right tool.

 

Using an Android device and a tool like Geocache Placer you will be able to get a VERY precise position for your cache, and on top of that you will be able to check the position on top of Google Maps. If you think the position can be even better, you will be able to move the red marker an get the position where you think the right spot are (the green marker)!

 

The yellow circles is the positions used in the calculation of the "Average position" The red line shows how the "Average position" has moved over time, when adding new positions the get a more precise position.

 

Edited May 2, 2013 by Gabriel333

[+randco]

The above is very interesting if a geocacher has a Smartphone. However, for those of us that don't, averaging seems the best way to get a decent set of coordinates. When I determine a cache location I try to us a 50 foot radius. Then I approach the intended GZ from as many angles as I feasibly can. I usually test the coordinates over several days before I get my final coordinates.

 

As cachers, it is our job to evaluate and publish the best coordinates that we can. After all, we "do" want people to find our hides. If we knowingly deceive other cachers with bogus coordinates, what's the point? A bona fide high difficulty cache should have the best coordinates we can provide. The camo should be the real test of the hide.

 

We all know that conditions and equipment will determine the accuracy of the cache location. Happy caching...

[+The A-Team]

...you will be able to check the position on top of Google Maps. If you think the position can be even better, you will be able to move the red marker an get the position where you think the right spot are (the green marker)!

Just to be clear, resources like Google Maps should only be used to do a basic check for major errors, like if your coordinates are hundreds of feet (or even miles) off. These maps are simply not consistently accurate enough to use for getting coordinates for a cache placement. You should be using the results of your GPS device, as is stated in the guidelines.

[Gabriel333]

...you will be able to check the position on top of Google Maps. If you think the position can be even better, you will be able to move the red marker an get the position where you think the right spot are (the green marker)!

Just to be clear, resources like Google Maps should only be used to do a basic check for major errors, like if your coordinates are hundreds of feet (or even miles) off. These maps are simply not consistently accurate enough to use for getting coordinates for a cache placement. You should be using the results of your GPS device, as is stated in the guidelines.

 

I agree! Google Maps are not always that precise, but in combination with the averaging you WILL get a precise position. Collection a large number of positions in 5-10 minutes will give you a very precise position. The tests I have done with Geocache Placer using the tool on "Satellite Google Maps" in Denmark, in the areas where I have tested Geocache Placer, showed me that the average position was exactly where I was standing doing the averaging. So in my area the Maps are very good. The benefit of this tool is that the user can do the test himself, testing if the maps and the GPS position is showing the same. If this is the case, Geocache Placer can be used.

 

It could be fun if someone with a good GPS device could test this against a tool like "Geocache Placer". If I had an GPS device I would have done this myself :-)