Adding control point - what are you controlling

Please post any further education or courses that are for laser scanning
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Re: Adding control point - what are you controlling

Post by smacl »

Augusto 3D wrote: Tue Feb 07, 2023 4:59 pmThe only thing that I can I think of, when it comes to TSL scans, is what we see in Faro: where you bundle and lock a set of c2c registered scans and push that bundle / cluster into control. Anything that happens is between is just "extrapolated"
Mobile mapping could give very different results here as C2C makes a basic assumption that scanner position is static and hence all the points from a given setup can be considered rigid in their own local coordinate system. This isn't true for mobile mapping, so while slicing the point cloud up allows the same technique to be used, it is hiding a few potential sources of error in doing so. Not sure how the different vendors process external control but I'd imagine the better approach would be to use it to adjust the trajectory file prior to attempting to coordinate the point cloud. You also have to consider that there is very little overlap on a single pass mobile mapping system and C2C depends on overlap. This is particularly true if the mobile mapping system is using a profiling LIDAR sensor (e.g. BLK2Go, Leica Pegasus, Z+F, Riegl vehicle mounted systems). C2C registration really only comes into play here where you have multiple passes over the same area (e.g. going up and down a road in different directions).

Great discussion by the way, from a survey background of a number of decades myself and I daresay I have an unhealthy obsession with control. :D
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