AltaLIS DEM Terrain data from Alberta

geoltechgeoltech Global Mapper UserPosts: 9
Has anyone loaded the AltaLIS data from Alberta, Canada? Did you load the data as three separate files or could it be loaded in a group?

The data is delivered in three file types. 
  • gnp files - masspoints 
  • ghl files - hard breaklines
  • gsl files - soft breaklines

ASCII SPECIFICATION

masspoint file:

Point id, X coordinate (UTM decimal meters), Y coordinate (UTM decimal meters), Z elevation value (decimal meters). 

Hard/soft breakline file:

Line id

start point X coordinate  Y coordinate and Z elevation

END

NOTE:  A -9999 value indicates that there is no elevation data for the location.

ASCII FORMAT SAMPLE

POINT FILE (GNP):

412,417338.59614,5900797.10471,1360

439,416996.93548,5900788,1440

452,417229.22581,5900781.70968,1400

457,417331.73333,5900779,1360

458,417695.77419,5900778.45161,1320

482,417900.85246,5900769.67213,1280

483,417327.3,5900769.5,1360 

HARD LINE FILE (GHL):

            70724

427613          5894574      -9999

427635          5894558      1278.46338

END

            312751

427635          5894558      1278.46338

427660          5894498      1278.46338

END

            70723

427552          5894524      1278.46338

427613          5894574      -9999

END

            312753

427660          5894498      1278.46338

427664          5894454      1278.46338

END

SOFT LINE FILE (GSL):

            72501

418605.32803          5900775.9117      1240

418617          5900666      1240

END

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Best Answer

  • kfroesekfroese Geotechnical Engineer Posts: 160
    Answer ✓
    Yes. I imported a bunch for some projects. Wrote a script to automate the process since we had several sites to process. I imported the masspoints as points and the other two files (hard and soft breaks) as "point and lines". When I generated a grid, I turned on breaklines. Gave a reasonable surface considering the (in)accuracy of the data.
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