View LIDAR at specifed height above ground

I was wondering if there was an option in GLOBAL MAPPER v18.0 that would let me export .las files at specified range, for example I would like to export .las file to raster but only points that are > 2m above ground? I can't find such option.

Answers

  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,883
    Hello,

    When you load your .las file, in the Limit What Points are Loaded section, there is an option to only load points within a specified elevation range ("Keep Elevations in Range").  Then you can export to any format.

    Cheers,
    Bob
  • huzarhuzar Posts: 4
    I don't have that option, only this.

     

    I'm using GLOBAL MAPPER v18.0. I think that this wouldn't solve my problem anyway. I have to show points that are 2 m above ground not sea level. 
  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,883
    Hello,

    Do you have the LiDAR Module? If so, you should be able to filter points by height above ground. Use the Digitizer to select the points in your LiDAR layer, then right-click and choose Advance Selection Options | Filter Selected LiDAR Points by Elevation/Color/Class, etc. The resulting window will provide options for unselecting points that are within your range above ground.  You can then delete the remaining selected points.

    This same function can be used during a LAS file export, so you could export your LiDAR data, and use the filtering options to remove points that are outside your desired range above ground. This will result in a new LAS file that contains the data you want. You can load this file and export the data.

    Cheers,
    Bob
    Francisco_Rodriguez
  • huzarhuzar Posts: 4
    Ok, this works ;) Do you think that this operation can be done in script so I can do it on several files at once? Is option "Select all features in layer" available in scripting?
  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,883
    huzar said:
    Ok, this works ;) Do you think that this operation can be done in script so I can do it on several files at once? Is option "Select all features in layer" available in scripting?
    Hello,

    You can use a script, but you will have to use the export method, which would look something like this:
    IMPORT  FILENAME="your LAS file"
    EXPORT_VECTOR FILENAME="LAS file in range" LIDAR_HEIGHT_RANGE="2, <your file's max height>"
    UNLOAD_LAYER FILENAME="your LAS file"
    IMPORT FILENAME="LAS file in range"
    // Your other export goes here
    Note that the IMPORT and EXPORT commands will require more parameters than are listed here. This is just an example. The LiDAR point selection functions available in the UI are not part of the scripting functions.

    Cheers,
    Bob
    Francisco_Rodriguez
  • huzarhuzar Posts: 4
    Ok, thank you for answer.
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