Global Mapper v25.0

Importing then exporting DTED2

rah
rah Global Mapper User
edited May 2012 in Technical Support
Hi, this may seem like a silly question, but I have tried loading a .dt2 file into Global Mapper and then exporting back to DTED2. I expected this would at most change some metadata stored at the beginning of the file. But on a diff of the files, it seems that some (very sparse) modifications have been made to the elevation data as well. When exporting, "Interpolate to Fill Small Gaps in Data" was not selected.

Can someone help me understand what Global Mapper is doing when it exports? I thought that if there is no datum transformation or reprojection, and no interpolation to fill gaps, the elevation data would be untouched.

Thanks.

Comments

  • global_mapper
    global_mapper Administrator
    edited May 2012
    How is the data changed? I would basically expect it to be untouched if nothing else is loaded. Do you have some sample binary value differences? If you load both the original and exported .dt2 files back in and use File->Combine Terrains to compare them are there differences?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com