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Distance difference in Google Earth with exported GPX or KML compared to source shapefile

Distance difference in Google Earth with exported GPX or KML compared to source shapefile


I've converted a shapefile (points) to KML with QGIS. Points in the shapefile are within 100m distance from each other. When I measure it in Google Earth, the distance changes to 80m. The same happens with the created GPX file. Why is this?

My original shapefile was created in WGS84/UTM Zone 20S because I needed to work with the metric system. I'm working with data belonging to an area no larger than 6 square kilometers. As to avoid the problem I am having now, I reprojected it to WGS84 (EPSG 4326) by "saving as" and changing its SRC before I then created the KML and GPX. Both KML and GPX show the same surface, the difference comes along with the shapefile.

Sample coordinates are:

id lat long POINT(-61.82795607536099425 -37.83722374457502724) POINT(-61.82861595101069696 -37.83772772712714527) POINT(-61.82724009148368083 -37.83767676392982793) POINT(-61.8278967620074269 -37.83817748597036257)

If your points are in UTM zone 20S, lat and lon should be swapped.

Reprojecting the coordinates to UTM 20S, I get the following x-y coordinates:

id;lat;long;x;y 1;-37,83722374;-61,82795608;603131;5811597 2;-37,83772773;-61,82861595;603072;5811542 3;-37,83767676;-61,82724009;603193;5811546 4;-37,83817749;-61,82789676;603135;5811492

The distance from one point to the next is 80.66 meters. If your original shapefile had coordinates of 100m distance, there must have something been wrong with the first reprojection you did.

Perhaps you should add the coordinates in the original projection too.