LiDAR Novice

HankJSHankJS Global Mapper UserPosts: 14Trusted User
edited March 2014 in Elevation Data
Though a user of GM for many years, I have not worked with LiDAR data. Is there a recommendation on tutorials for the beginner to load the data and perhaps drape raster maps and/or ortho photos over the point data for 3D visualization. I am using GMv14 and demo of GM15. Any help would be appreciated. I have a few quads of USGS LiDAR point data for northern DE and PA.

Regards.
Hank Sundermeyer
Newark. DE

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2014
    Hank,

    There is a webinar focused on Lidar handling in Global Mapper near the top of Blue Marble Geographics Previously Held Webinars. I would suggest watching that, or at least the beginning as it may get more advanced that you need for the later parts.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • HankJSHankJS Global Mapper User Posts: 14Trusted User
    edited March 2014
    Hank,

    There is a webinar focused on Lidar handling in Global Mapper near the top of Blue Marble Geographics Previously Held Webinars. I would suggest watching that, or at least the beginning as it may get more advanced that you need for the later parts.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

    Hi, Mike

    I looked at that Webinar, got lost pretty fast when it drifted into the LiDAR plugin. What I Have been able to do is load the point cloud and create an elevation grid then add a DRG or DOQ drape over the grid for the 3D effect. This is what I came up with, whether that's the right approach I have no idea. If it is, there's probably more refinement to work on.

    Regards,
    Hank Sundermeyer
    Newark, DE
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2014
    Hank,

    That is really all that you need to do to get a 3D view, just load and grid the Lidar, then load something else on top and open the 3D view. Or enable texture mapping for the image layers on the Options dialog for them to apply shadowing from the terrain data.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • HankJSHankJS Global Mapper User Posts: 14Trusted User
    edited March 2014
    Mike,

    I've seen some video demo's where gridded LiDAR data that has a DOQ overlays. In the 3D view, tall buildings, the vertical sides are almost transparent rather than "solid" with angular surfaces solid. Is that a visualization I can perform in GM15?

    Hank Sundermeyer
    Newark, DE
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2014
    Hank,

    There isn't currently a way to do that as the terrain surface is filled in completely, but we are working on 3D view enhancements that will likely allow taking 3D building areas and just applying imagery to the top of those and not the sides. That's not available yet though.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • HankJSHankJS Global Mapper User Posts: 14Trusted User
    edited March 2014
    Hank,

    There isn't currently a way to do that as the terrain surface is filled in completely, but we are working on 3D view enhancements that will likely allow taking 3D building areas and just applying imagery to the top of those and not the sides. That's not available yet though./QUOTE]

    Hi, Mike

    Probably, 15 will be the end of expansion in the basic product without purchasing an expensive ancillary plugin.

    In creating the LiDAR elevation grid either with the initial LAS load option dialog or with the menu analyze/Create grid after the point cloud is loaded, is there a way to remove the single point spike anomalies? Some of them get high enough to interfere with civil aviation.

    Regards,
    Hank Sundermeyer
    Newark, DE
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2014
    Hank,

    There is an option when loading the LAS data to specify to remove any elevations more than some number of standard deviations from the mean which will often help in identifying anomalous points automatically. As an alternative after gridding the data you can go to the Alter Elevations tab of the Options dialog for the grid and specify what the maximum valid value is so any points over that are marked as invalid. You can do the same for Lidar point clouds if you have the Lidar module.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
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