Global Mapper Pro

Adjust DTM to control points

Hi everyone,

I need to adjust an existing DTM (grid or contour lines) to measured control points. The existing DTM is an available file from a public insitut, and de control points are GPS measured.

I see it is possible to do so from a lidar point cloud file (.las), but I wonder if it is possible directly on the grid file or the contour lines.

I need the countour lines to fit my measured points.

Thank you in advance.

Best Answer

  • bmg_mike
    bmg_mike Global Mapper Guru
    Accepted Answer

    While you cannot do this directly on a terrain / contour layer, what you can do is the following:

    1) convert your terrain layer to a point cloud using the Layer -> Terrain / Point Cloud -> Create Point Features at Elevation Grid Cell Centers menu command

    2) use the Lidar QC tool to adjust the new point cloud to your control point

    3) use the Create Elevation Grid tool to grid the adjusted point cloud

    4) create contours from the new adjusted grid created in step 3

    Thanks,

    Mike

    Global Mapper Guru

    geohelp@bluemarblegeo.com

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