Global Mapper v25.0

Interpreting asc grid DEM

I've tried a hit-all-buttons approach without success - can someone help a noob load a file please?

I received some data from a nation park in new zealand - It appears that the lat long is in the header and I'm assuming that the grid is relative to that.

Here is the header:

ncols 4800
nrows 7200
xllcenter 1804002.500
yllcenter 5658002.500
cellsize 5.0000
nodata_value -99

and it appears that all of the values in the columns and rows are just elevations.

Any assistance would be very much appreciated. During my attempts my results are garbage or error messaged saying that it can't load the data.

Thanks

Dave


Answers

  • bmg_bob
    bmg_bob Global Mapper Programmer
    Hello,

    Can you be more specific about what you mean when you say that the results are "garbage"?
    What version of Global Mapper are you using?

    Can you zip up your file and post it here?  This will make it easier to figure out what is going wrong.  If you don't want to post it here, or it is too large (I don't know what the limit is), you can send it by e-mail to geohelp@bluemarblegeo.com.  If it is too large to attach to an e-mail, the support folks at that address will give you information for other ways to get us the file (FTP, Dropbox, etc.).

    Cheers,
    Bob
  • Hi

    Here is one of the zipped files.

    The 'garbage' is a mesh of different shapes from one of the many times i tried importing.

    Once it looked like a color space gamut diagram, another like a very smooth witches hat. Rather than the mountainous data that I'm expecting to see.

    Geotiff of the same area works fine, but this is a denser DEM.

    Source: http://data.waikatoregion.govt.nz:8080/ords/f?p=140:12:0::NO::P12_METADATA_ID:3

    Thanks

    Dave

     
  • bmg_bob
    bmg_bob Global Mapper Programmer
    Answer ✓
    Hello,

    That link seems to just go to the metadata.  Do you have a link to the file?  

    What workflow did you use to import the file?  It looks like an ArcInfo ASCII Grid file, and can be opened using File | Open Data File(s)...  Choose the "ESRI (ArcInfo) ASCII Grid Files" file type.

    Cheers,

    Bob
  • So the problem was that I was selecting the import as text file option. 

    Your suggestion worked.

    Thanks very much Bob