[GRASS-user] Re: Is it possible to export a Raster to KML
hamish_b at yahoo.com
Fri Oct 28 16:05:35 EDT 2011
> > in my experience overlaying kml (vector and raster)
> > with EPSG:4326 in google
> > earth works relatively well in flat areas, in mountain
> > areas there are
> > sometime distortions therefore.
> I can confirm this from my (limited) experience to export
> data to KML. To correct for the geoid heights, you could use
> the previously indicated map and calculate the local
> ellipsoid-geoid difference and vertically shift your vector
> data with v.transform.
> Then export to KML. For raster, use r.mapcalc to shift.
n.b., IIUC raster KML support in google earth is essentially a
hack building on/abusing their raster-icon support.
they may have improved things, but this is what I was lead to
believe at the time of writing r.out.kml.
probably it is useful to consider if the ellipsoid-geoid
difference is important vs. the overall vertical differences
in the data, if the result is just for viewing maybe it is not
worth the trouble.
More information about the grass-user