# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: How accurate is pinned lat & long on Google Earth?
Date: 2017 Feb 27, 17:26 -0500
David

You stated that GE provides three decimal places of a minute.

Therefore, Google Earth has a *resolution* of .001 minutes.

1852 meters * 0.001 = 1.852 meters ~2

We can say that Google Earth is resolved to 1.85 meters, or that it has a resolution of 0.001 arc minutes

The result of your experiment provided an *accuracy* of 6 meters.  That is, even though the resolution permits positions to be resolved to within 1.85 m, the accuracy of that specification is only good to 6 meters

On Feb 27, 2017 4:10 PM, "David C" <NoReply_DavidC@fer3.com> wrote:

I have just carried out a little experiment. I placed my phone on a table outside where it had a view of the clear sky. I waited until it was it had 15 satellites in view and was using 14 or 15 of them.  Sometimes it dropped to 14/13.   Both US and Russian satellites were used. Claimed accuracy was 5m - I assume this is calculated from the constellation.

Google Earth gives  positions to three decimal place of a minute. According to Mr Google 1 nm = 1852 m so the precision [1] of GE is approximately 2m.

My measurements were:

GPS    06.454'  S

05.204' E

The app gave the numbers to four decimal places which implies more precision than is real.

05.205' E

From which:

dlat = .003'    approx = 6m

dlong = .001'   At lat 41°  dep  approx equal 1.5m

Conclusion: At my location the GE and GPS positions agree within the claimed accuracy of the GPS.

There is a clear blue sky outside with no wind. I must take my sextant and determine the CORRECT position of my garden table (-;

[1] I am sure that precision is the correct word here, not accuracy.

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