03 - Computree

For deriving DTM:
METHODNAME = ComputeDTM
PARAMETERS = cellsize, windowsize, smoothingneighbourhood

I can not help you with DSM, but when you set parameters or set inputs in the upper part of the window you can read the methodname.
Cheers, Chiara

Hello,

The only publication containing informations about this DTM method (plugin ONF) is (but description is very short):
https://hal.archives-ouvertes.fr/hal-00646403/document

In the ONF plugin, the step are : ONF_StepClassifyGround (classification of ground points in TLS) and ONF_StepComputeDTM02 (interpolation).

ONF_StepClassifyGround works as follow:
- Compute a Zmin grid at specified resolution
- Filtering by point density in a slice of specified thickness from ZMin
- Filtering by neighborhood consistency (slope test between considered cell and neighbors cells)

ONF_StepComputeDTM02 compute a Delaunay triangulation on not filtered Zmin cells, and interpolate missing ones by a pondered mean (pondered by distance of neighbors in the triangulation). So a method close to a "natural neighbor interpolation", using distances instead of triangles areas.

The DSM creation is just a ZMax computation by ONF_StepComputeDSMOnly step.

If you use the method provided by plugin SimpleTree, please ask to Jan Hackenberg directly.

Best regards.
Alexandre Piboule.

Thanks for all your reply. I also wanted to know about the spatial resolution of DTM and DSM obtained from CompuTree. How can i get spatial resolution information of my result DTM?

Looking forward to your reply

Thanks in advance

Suman

Hello,

The easiest solution is to:
- Select "Item information" action,
- Show your DTM/DSM in the view,
- Select it, all informations about it (including resolution are displayed on the screen and in the log. Resolution is in meters.

Other ways are to send the DTM/DSM to a tabular view, or to export its attributes to a file (menu Export/3D Geometry/Attributes export (csv))

Best regards.
Alexandre Piboule.