Determine Tree Height With "Tin Difference" Tool

[EricRuthford]

Hi,

I have two TINs I am using. They were created by the county government using LiDAR data. One is a digital ground model (bare earth) the other is a digital surface model (tops of vegetation / buildings). I am trying to subtract the DGM from the DSM to find the heights of the trees.

I think the best tool for this would be the "Tin Difference" tool, which works and then puts out results you can express in volume, area and code. However, this data makes no sense, the units seem to be nothing close to meters, feet or anything, and the values go up into the millions.

Any help you could offer would be appreciated. I am relatively new to Arc, and this is my first experience with TINs.

Thank you,
Eric Ruthford
Student / unemployed hobbyist

[MikeMazerolle]

I've just recently been trying to solve a similar problem.

Take a look at this document for some help: http://www.esri.com/library/whitepapers/pdfs/lidar-analysis-forestry.pdf

Also, if you are using ArcGIS 10, I found a section for "Estimating Forest Canopy and Height", so if you try a search there, you might have luck.