Am Mon, 24. Jul 2017 um 20:30:08 +0200 schrieb Oliver Eichler: > Hi Guido,
Hi Oliver, > I do not understand why the elevation filter "Interpolate Elevation Data" > with > setting "coars" does not fit your need. The used spline interpolation is much > more natural than a linear interpolation. yes and no. The spline interpolation provides no chance for improvement for very narrow valley situations like in the attached graph. The plot around 15 km +-3 km in reality is at 2150 m (Río Marañon valley). A linear interpolation would give a chance to eliminate this error (more than 200 m!) completely. > But either linear or spline interpolation will not provide good results if > your input data is faulty. Especially along steep walls a few meters > deviation > in the horizontal plain can result in a significant difference of the > elevation. In that case you have to reduce points to a minimum. And fine tune > the position to a better fit. Yes that is clear but this is no solution for narrow valleys where DEM data gets wrong due to its "natural" behavior. The linear interpolation would just be a tool to make elevation gain calculation much easier. It would also help in your case of a not so precisely painted route. Guido -- http://wie-im-flug.net/ http://www.lug-burghausen.org/
signature.asc
Description: PGP signature
------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________ Qlandkartegt-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/qlandkartegt-users
