Distance measurement in Google Earth

I have been measuring hillside paths created by indigenous people in the Southwest.  I measure the length of the path with a tape measure.  I also locate the base and high points of each path with a GPS system.  Using the UTMs I draw a straightline on Google Earth between points.  THe properties length is different from the elevation profile distance length and they are both different (several meters if not more) from my taped length.  Any thoughts on what may be going on here?

Hi,
Perhaps, best answers can be obtained in the Help Forum:
support.google.com/earth/community

Hi, Andy,

It's possible that the problem is down to the elevation data used by GE.  IIRC, the resolution is pretty low, at around 90 meters, which would give significant discrepancies in your calculations.  The developers' page for GE elevation data says:

The Elevation API returns data for single point queries of the highest accuracy possible. Batch queries involving multiple locations may return data with less accuracy, especially if the locations are spread apart, as some smoothing of data occurs.

The GEC is not affiliated in any way to Google any more - as Tek says, you'll find the real experts over at the GE help forum; if they don't know the answers, they'll know someone who does!