Comparison between Google Elevations API and SRTM3 Data

http://members.chello.at/stephen.joung/indexGoogleHeights_v3_2.html

Interesting little app which compares the elevation data from Google Elevations API and the SRTM3.  If I am not mistaken, Google uses the SRTM3 data as a base, but from what I see in the comparisons, the data is much smoother, in other words, it seems it has some been further interpolated.  While the SRTM data seems lower resolution, for some cases it seems like there is more accuracy.  We do know that Google does interpolate:

In those cases where Google does not possess exact elevation measurements at the precise location you request, the service will interpolate and return an averaged value using the four nearest locations.

Anyways, thought I would share...

edit: Looking deeper, it seems that Google uses hundreds of data providers to get the higher resolution terrain information.