How to find the height information from LiDAR point cloud data [duplicate]

Question

I need to find the biophysical parameters(biomass) from the LiDAR point cloud data. For that I need the height of the trees from the data. Currently I am having the general height with respect to sea level(400 range).

I tried with lasheight, and also tried to create dem and dsm and from them chm but nothing is working with the data set. I have attached my las data too below.

Data

I tried with lasheight, and took the output, its supposed to give the height information as 0 for ground and for the trees for example 10m or something. but I'm getting the same 400 range values for ground and trees.

I tried with las2dem and tried to save its output as tif image.(I am programing using R), while reading that tif image to R. Its giving error. Its not taking that tif image

Answer 1

PDAL can do this for you, and the easiest way to use PDAL is to install Docker Toolbox and then follow the PDAL Docker Tutorial to verify you have the basics working. Once you're confident things are good, run the following command on the data:

docker run -v //c/Users/Howard:/data \
    pdal/master \
    pdal translate //data/point_cloud_classified.las //data/height.laz height ferry \
     --filters.ferry.dimensions="Height=Z"

This approach is taken directly from the PDAL Normalized Heights tutorial.