Global Mapper v25.0

Elevations from DEM/Disc Image file come in 3x times higher than expected

Hello,

Im trying to generate some contours using some DEM/Disk Image files from the Virginia ArcGIS found here near Lynchburg Virginia (specifically tile S13_27_2022). Every time I bring the DEM tiles into Global Mapper, they load in the proper spot (horizontally) but the elevation footage is way-way too high.

My suspicion is that Global mapper thinks the units are supposed to be in meters (in reality the measurements should be in feet) and then by default converts them to meters (making everything 3x normal elevation)? I also had the same issue with this trying to make contours using DEM data from Indiana's website (IU.edu GIS portal).

Changing the projection does not convert this to the proper elevations. I think it has to be something that I'm not importing them or there is a setting I don't have quite right.

Can I get some help getting the proper elevations?

attached .zip is the metadata

Screenshot below shows elevations 3x their normal height (believed to be a global mapper conversion from feet to meters)


Thanks,

O

Best Answer

  • OROB_BGA
    Answer ✓

    I figured out how to fix elevations that don't come import under the same unit measurements as the metadata. Follow these steps

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