Global Mapper v25.0

Why won't GM write reliable USGS DEMs?

skymapper
skymapper Global Mapper User
We are having issues when importing Arc ASCII grid format and trying to write USGS DEMs.  The output quality is sporadic.  It either works, crashes ArcMap or writes files with elevations in scientific notation.  The files are not readable in Arc.

Thanks.

Answers

  • jubxie
    jubxie Global Mapper User
    Some further info on this issue:
    It seem to write 2' DEM's ok but has trouble with some 1' DEM's (elevations have sci notation in ArcGIS).
    It also writes them correctly when importing and exporting only one DEM. When I bring in a whole project and have GM cut tiles based on an existing tile layout, it writes some of the DEM's with sci notation for elevation, as viewed in ArcGIS.
    Also, GM 16 seem to create unreadable in ArcGIS DEM's that are above 1000'....... 15 doesn't have this issue.



  • skymapper
    skymapper Global Mapper User
    This issue was reported in September 2015, and hasn't received a comment from Blue Marble.  Can someone please address this?

    Thanks.
  • bmg_bob
    bmg_bob Global Mapper Programmer
    Hello,

    I ran a quick test, exporting a USGS DEM to Arc ASCII Grid using Global Mapper 17.2.2, and was able to load it into ArcMap 10 without problems.  Also, the data is not in scientific notation.  If you are using Global Mapper 16 or 17, you can download the latest release to see if that fixes the problem.  If the problem persists, I recommend that you send an e-mail describing your workflow and the results, with a copy of sample data that will reproduce the problem, to Blue Marble Geographics support (geohelp@bluemarblegeo.com).  This will ensure that the support team sees the problem and can provide you with a timely response.  Thank you.

    Cheers,

    Bob

  • skymapper
    skymapper Global Mapper User
    Thanks, @bmg_bob.  This problem appears to have been fixed.
  • jubxie
    jubxie Global Mapper User
    New issue with USGS DEM (and possibly other formats). I can repeatably export USGS DEMs in Oregon North/NAD83_2011/International Feet, and when I load them back into GM, they don't ask for a projection and put the data in a geographic projection. If I change the projection of the layer to OR....it puts it in the correct place. This doesn't happen in Washington. It's either an issue with Oregon or International feet. Happening at least in 17.2 and 18 (as of a week or so ago). We only noticed this issue as another sofware package was having trouble with the Oregon DEM generated by GM.
  • bmg_bob
    bmg_bob Global Mapper Programmer
    Answer ✓
    Hello,

    I recommend that you send an e-mail describing your workflow and the results, with a copy of sample data that will reproduce the problem, to Blue Marble Geographics support (geohelp@bluemarblegeo.com).  This will ensure that the support team sees the problem and can provide you with a timely response.  Thank you.

    Cheers,
    Bob