Horizontal Exaggeration???

nitrocrusher
nitrocrusher Global Mapper User
edited February 2008 in Elevation Data
I've got a 5 meter ASC file that I downloaded from my states GIS website. The file has a UTM NAD83 meters projection. The problem that I have is that when I export it to a DXF for 3D modeling the vertical distance is correct, but the horizontal distance is about half of what I would expect it to be (i.e. - looks steeper than in reality). Is there something that I am doing wrong, or is there a better method to correct this? Thanks in advance.

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  • global_mapper
    global_mapper Administrator
    edited February 2008
    Make sure that you are selecting the proper elevation units when loading the file, and also selecting meters as the output elevation units when exporting. It sounds like maybe you have elevation units in feet and horizontal units in meters or something, resulting in the distortion.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • nitrocrusher
    nitrocrusher Global Mapper User
    edited February 2008
    Thanks for the quick response. I'm not sure what I was doing before, but I did exactly what you said and checked all of the units before opening and exporting and it appears to have worked. Is there something that I should do beforehand to get it into inches or feet since those are the units that I will be working with? Do I just scale up the DXF by a factor of 3.28? I appreciate your help.
  • global_mapper
    global_mapper Administrator
    edited February 2008
    The important thing to do is the make sure that you select the correct elevation units for the file when you load it. The elevation units selection is on the same dialog as the projection selection. So if the elevation values in your DXF file are in feet, be sure to select feet as your elevation units. This way they can be converted correctly on export.

    If you want feet in your output and want it to scale properly with the X and Y values, you'll need to set up your projection to have feet as the planar (horizontal) units rather than meters.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com

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