Global Mapper v25.0

Importing elevation data without "webbed-feet"-like extrapolations.

sktse
sktse Global Mapper UserTrusted User
edited August 2013 in Elevation Data
I've been trying to import a large amount of data that does not have a rectangular bounding area - it follows a winding watercourse.

This means that at the edge of the surface data, there is an acute angle, and in this acute angle, Global Mapper will try to extrapolate heights in between these areas, resulting in a "webbing" of sorts of highly inaccurate data. I have some coarser data that I would like to merge with this high-density dataset, but unfortunately, this webbing will overwrite the data. I have a picture of an example of what I mean, but unfortunately, I am having trouble uploading pictures to the forum.

I've tried to play with the "Tight/Loose" settings on the DEM import, but if I make the setting too tight, then the points in the DEM won't be interpolated in each other.

Is it possible at all to remove this feature from Global Mapper, so that the points within the coverage area are interpolated, but outside the coverage area Global Mapper does not try to extrapolate them? Unfortunately due to the sheer size of the data, it is very difficult for me to do additional processing like building bounding boxes without Global Mapper crashing (perhaps due to lack of memory).

Thanks very much for your help!

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