Combine Z+F Scans (Non colour) + Images

Comments

6 comments

  • Avatar
    Ondrej Trhan CR

    Hi,

    are you using GCPs in this project?

    I think it is not needed to export both registrations. You can add the one to another project. Did you have set also output coordinate system?

    According to first look it seems, that photogrammetry component is moved from its position. Is it possible to turn off the Camera priors just for images and them align the components? Were you using RTK drone? If not in that case turn off the Camera priors for images and you can try to align also using option Merge georeferenced components in settings.

    In some cases it is needed to use control points to merge these kind of datasets, so what you find about marking targets on laser scans' LSPs is true. 

    0
    Comment actions Permalink
  • Avatar
    D2RS

    Hi

    Yes I had targets on the walls measured with a total station.  The images are ground based, no drone.  The DSLR camera has a consumer grade GPS for a rough position. 

    OK Setting

    Image set prior pose to unknown

    Geo-referenced Yes

    Scans locked and Geo-referenced

    Alignment

    Merge Geo Components YES

    Force Component rematch YES

    Position prior hardness 0.5

    This resulted in two separate components, the scan residuals seems odd as from infinity or 0,0,0 where as they were imported as exact.  In Laser Control I update the registration to the scan files but I imported the project file anyway.

    So the scan priors are exact, the DSLR priors are rough but I have registered to targets as per scans.  Logically at least merging two Geo-referenced components should dump them in the same position if not aligned to each other.

    Its as though one is budging the other, the alignment settings conflict one or the other component.  I have tried adding one to the other and vice versa.

    I have had the same issue on previous jobs and marked the targets in the scans so I guess I should try that.

    Thanks

     

    0
    Comment actions Permalink
  • Avatar
    Ondrej Trhan CR

    Did you use those targets also in the project? Are the laser scans on the correct position if you import them into RC?

    I don't think it is needed to lock the laser scans.

    I would import laser scans as exact and align them.

    Then import images and GCPs.

    Set No for Use camera prior for georeferencing in Advanced Alignment settings.

    Measure some of the GCPs over images (minimally three).

    Align using Merge georeferenced components.

    If this won't merge the components, then I would also measure/place these GCPs also on laser scans' LSPs (the same as for images) and align again.

    Do you have set the right project and output coordinate system?

    Can you show me 1Ds view with GCPs?

     

    0
    Comment actions Permalink
  • Avatar
    D2RS

    OK so adding targets to the scans has brought the images to the party.  This isn't ideal as commonly I window scan targets on higher resolution so the targets may not have great definition in the standard scans.  Plus we are hand picking the centre point instead of auto extraction = residual errors.

    What we have here is two Geo-referenced components that are not aligned to each other except by the targets.  My impression of the tutorials is that the scan data tie points are aligned with the image tie points.  When I re-align with merge Geo-referenced components OFF, they don't align.

     

    0
    Comment actions Permalink
  • Avatar
    Ondrej Trhan CR

    Is it possible to share these data?

    If you have georeferenced data in the same coordinate system they should align.

    I can see a big residuals for the images, there could be something wrong...

    The scans and images will merge if there is a good overlap between datasets. Also, if the laser scans would be color, it should be easier to merge these together.

     

    0
    Comment actions Permalink
  • Avatar
    D2RS

    1ds with control points.

    I'll try your workflow, I watched a tutorial which did say to lock the scans which does make sense.

    0
    Comment actions Permalink

Please sign in to leave a comment.