Global Mapper v25.0

DTM Smoothing


May I know any tools to smooth the DTM data like Spline available in Global Mapper. Basically I have generated DTM in ASCII Grid format with 1meter postings and it seem very rough.Hence, I'm looking the smoothness function to enhance the cartographic of DTM.

Please advice.

Thank you


  • Bumping this question. I know that flattening elevation is doable in GM but the problem is that one must make a polygon and then select alter elevation values based on the height. The process itself is fine but it's a bit cumbersome when another program out there lets you literally draw a polygon, right click, click "smooth", and without any other input it smooths the elevation you selected (so getting rid of spikes, trees, various other occlusions, etc.) It also doesn't need to create separate layers to do so - it just happens automatically. 

    Is this a feature in GM and I'm not doing it right?
  • Ditto on this, is there an "auto smooth" option for the DTM somewhere? all I want is for GM to do a nice smooth curved line between points instead of near 8 bit looking square blocks stacked on top of each other.

  • bmg_mike
    bmg_mike Global Mapper Guru Moderator, Trusted User

    There is a Terrain Painting tool in GM that includes a smoothing option. Any edits to the terrain can be exported to a new file.

    There are also Resampling methods available on the Options dialog for the layer (or on export). You might try the Gaussian Blur or Box Average resamplers to see if one of those gives the desired results.



    Global Mapper Guru