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This is somehow a good post that gives me a bit of direction; Retrieving LiDAR metrics from relative vertical layers of point cloud

I'm using FUSION and rLIDAR most of the time. I'm looking for a way to detect understory crown for Individual tree. So the steps done so far, I've had done generated CHM, applied watershed delineation and extracted the raw LiDAR returns from each segmented area. Meaning i had saved all the point clouds into separate las files represent individual tree. So there's thousands of trees for my study area. Right now, i'm looking for a way to plot a histogram and get the height threshold and then separate the point clouds based on the threshold (because later i need to process the lower layer CHM for the understory).

From @Andre Silva answer in that post this is something that i can interpolate, but can anyone advice me in terms of giving me example step using R if possible on how to do this histogram profiling, thresholding thing and separate the point clouds based on the threshold.

closed as too broad by Andre Silva, PolyGeo Nov 18 '16 at 22:44

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • Are you sure it was possible to segment the understory trees applying a watershed in a CHM? Usually lower trees are not detected with such type of data and method (depends on the forest, though). What criteria do you have in mind to define what is understory and what is not (using the cumulative distribution of return heights and detecting some kind o breaking point; or perhaps visually inspecting the height profile to see if the distribution is bimodal?). I think you can narrow your question, so to avoid multiple issues in one post (continues). – Andre Silva Nov 18 '16 at 21:40
  • Also, add some code showing what you already have so we can have an idea what your workflow looks like, for example, are you importing the lidar clouds in R (if yes, how?). – Andre Silva Nov 18 '16 at 21:46

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