I have a shp polygon in GGRS87/Greek Grid. I want to display the polygons on googleearth. I use "layer to kml" tool in ArcMap. However when I open the kml in googleearth the polygons are not aligned correctly (they are all moved southwest from their right position).

Has to do with the transformation of datums?

Notes: 1) in the tool I clicked on environments and as coordinate system I chose GCS_WGS_1984 and for transformation: GGRS_1987_To_WGS_1984 2) before applying the layer to kml tool, I tried to use Project tool to change the coordinate system to WGS84. But for an unknown reason I didn't have the option to use geogr. tranformation

  • 1
    did you use ArcMap for the projection? – Moh Feb 16 '18 at 13:34
  • while not a direct answer this page may help you rmseifried.wordpress.com/2013/01/09/… – user92055 Feb 16 '18 at 16:40
  • 1
    If you're not getting a geographic transformation, try redefining the data's coordinate system to the Esri GGRS87/Greek Grid version. There may be a difference in the GGRS87 definition that's making it not equal the one in the transformation. – mkennedy Feb 16 '18 at 19:08
  • What GIS software are you using? – PolyGeo Feb 16 '18 at 20:54
  • You might want to look in the Source tab under your layer properties, to see if the Reference System was assigned with the Esri-recognized WKID code. If not, you might want to run the GP "Define Projection", as GGRS87, and then proceed to Project and then Conversion. – AlecZ Feb 16 '18 at 23:09

Use WEB Mercator it would work.

  • Before converting the shp to kml, I first used the Project tool and as output coord. system I selected "WGS_1984_Web_Mercator_Auxiliary_Sphere" (from Proj. C.S\World) and used the GGRS_1987_To_WGS_1984 transformation. Unfortunately, the kml produced in the next step has the same false alignment (shifted southwest) – cartographer67 Feb 19 '18 at 7:15
  • Can you share some sample data so that i can reproduce the problem and check it. – Sandeep Kumar Feb 20 '18 at 7:55
  • Data: we.tl/uX9caVwXUl I am still trying but nothing yet. And here is a paradox: When I open the data with QGIS and save them as kml (I select WGS84, EPSG4326 as CRS) the polygons are correctly sited in google earth. BUT if I make any analysis in ArcMap 10.4 (eg I selected some of the poylgons and extracted them as a new shapefile) then when I follow the same procedure in QGIS the polygons of the new kml are misaligned as did in the ArcMap! – cartographer67 Feb 21 '18 at 9:54
  • And here is the kml with the correctly aligned polygons: we.tl/BhjiUcyp7f – cartographer67 Feb 21 '18 at 10:00
  • what is your default workspace in arcmap check it once – Sandeep Kumar Feb 21 '18 at 10:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.