Arcgis Layer to KML (google earth)

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06-13-2014 01:59 AM
thomasdesalle
New Contributor II
Hi there,



I've been struggling for ages trying to export a layer file (either vector or image to google earth).
I have been using Layer to KML export function but the result is always wrong.
I'm in the uk so the original layer is in OSTNO2 coordinates. I've try to export to different coordinates system but it's always out on the same location wrong by a few ten's of meter. As you can see below my outline should fit within the field and not be on the road!!!



I've attached a zipped folder which contain the layer file, the origin shapefile and the kml exported.

After trying for ages I gave up thinking that there is some projection incompatibility between ArcGIS and google earth and I was surprised to find no solution on internet of a problem that I imagine would be very common.
But this week I had a demonstration from a sales man working for trimble. We processed some GPS data using Trimble Business Office. And by a simple clic, all our data within TBO were display on google earth with very good accuracy.

So this let me to think that they MUST be a way to do the same with my layer and shapefile in ArcGIS. I would be greatfull to hear if you have the same issue or know how to solve it!

Thanks
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4 Replies
markdenil
Regular Contributor II
KMLs are always in lat/long coordinates.
project your national system coordinate data to wgs84 geographic,
and see how it lines up then.
Compare it to other available data in lat/long coordinates, too; not just the stuff in Google Earth.
(Remember too, that Google Earth fudges a lot of coordinate calculations in the interest of fast display.)
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KevinHibma
Esri Regular Contributor
Mark's answer above is correct.

Just to expand on it - the tool converts to WGS84 on your behalf if your data isn't already there. Doing this on your behalf it guesses at the best transformation (if one is needed). I'd use the Project tool to be absolutely certain about which transformation is being used and ensure the accuracy of your data as "WGS84" before converting to KML.

And of course, Mark's point about comparing to other data is very important. I've seen other "complaints" about data not lining up, and in the end its the imagery that isn't right. The data is "where its supposed to be".  Unless you have/own the data, be skeptical about how authoritative it is, in this case, the imagery.
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IanMurray
Frequent Contributor
Also always be sure when using kmls in google earth that you make sure either terrain is off, or that your kmls are clamped to the ground.  THis can distort the lines of kmls and make lines look off.
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ChrisSlinko
New Contributor II

I'm having the same problem but when shapefiles are created from a CAD drawing then brought directly into Google Earth then I create a shapefile in  ArcMap the CAD generated shapefile and the ArcMap shapefile don't line up they are off by 3 feet.  I played around with projections an I found that NAD27 works and make s the 2 line up. This caused a lot of problems it would be nice if we could just export directly form state plane and come into the correct place in GE

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