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Spatial resolution & method name used for deriving DTM and DSM (Computree)

Added by Ghimire Suman over 1 year ago

Hello guys,
How can i get information relating to spatial resolution of the DTM and DSM derived from Computree. Similarly, what is the method name used to derive the DTM and DSM using Computree. I am required to put the method name and spatial resolution in the figure caption.

Thanks a lot.

Best Regards,

Suman Ghimire
Nepal


Replies (4)

RE: Spatial resolution & method name used for deriving DTM and DSM (Computree) - Added by Torresan Chiara over 1 year ago

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

RE: Spatial resolution & method name used for deriving DTM and DSM (Computree) - Added by Piboule Alexandre over 1 year ago

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.

RE: Spatial resolution & method name used for deriving DTM and DSM (Computree) - Added by Ghimire Suman over 1 year ago

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

RE: Spatial resolution & method name used for deriving DTM and DSM (Computree) - Added by Piboule Alexandre over 1 year ago

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.

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