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GPS coords and Google Earth


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Ok. I'm looking at placing my first cache. I scouted out my location. Checked it twice today to get an average of the coordinates. I even used 2 different GPS receivers. Both of them were reasonably close to each other so after averaging out my results I decided to check them inn google earth. To my astonishment, when I type them in I am beamed to a location nearly 3 miles away from my GZ. Is this common? I don't want to think it is my hardware as I went caching this afternoon and it performed as necessary. I'm just not wanting to start a wild goose chase.

 

Mikey

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Ok. I'm looking at placing my first cache. I scouted out my location. Checked it twice today to get an average of the coordinates. I even used 2 different GPS receivers. Both of them were reasonably close to each other so after averaging out my results I decided to check them inn google earth. To my astonishment, when I type them in I am beamed to a location nearly 3 miles away from my GZ. Is this common? I don't want to think it is my hardware as I went caching this afternoon and it performed as necessary. I'm just not wanting to start a wild goose chase.

 

Mikey

It's likely due to a differences in datum - is your GPSr set to WGS-84?

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Ok - I grant you that 3 miles is a looooong way. However - why check GE?? What makes you think thier coordinates are any better than yours?? In many cases - they aren't.

 

type in your coords again - make certian you got them right - convert to decimal degrees if you have to.

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I had a very similar experience. I was riding an area where I might hunt this upcoming year. I dutifully marked out gates, stands, road intersections, and other landmarks into my GPSr. Got home to the computer and started playing with Google Earth. While some coords I wasn't 100% sure of (trail intersections, for example), others I was (like gates, structures). The conversion from GPSr coords (N XX deg XX.XXX etc) didn't match up with GE's formula. I wasn't 3 miles off on any of my marks, but far enough that marking a property boundary to avoid trespassing could get dicey.

 

I will have to check my datum setting. I hadn't thought of that while we were in the field.

 

Good luck. No matter what GE is very cool, especially showing stuff to our little pathfinders.

 

PF4

 

:)

Edited by Pathfinders4
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Nobody in this thread has given enough data for anything to actually be analyzed.

 

Google can read data from most popular GPSes directly. No excuses about datum settings or conversions or coordinate formats or such.

 

You'll have the same degree of success moving KML, GPX, or other files with well-defined specs.

 

You will see some shift between images and fixed points in some areas. Tens of feet are common just due to the way that imagery taken from the sky warps when put on the round-ish planet. Hundreds of feet aren't unheard of. Three miles, if true, warrants a bugreport.

 

Almost every time I tie into one of these reports, it's someone doing something like typing a decimal degree coordinate ("12.34567") into a device or program set for degrees, decimal minutes ("12 34.567") or degrees, minutes, seconds ("12 34 567") or such.

 

If you're sure that Earth and whatever source you're getting the data from are using matching formats and you want help studying a specific coordinate pair, please post details for analysis.

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