 trees depending on their distance to the
TLS device. Detection functions are fitted to the histogram representing
the distribution of the trees relative to their horizontal distances.
The computation of the detection functions is based on the data frame of
the detected trees, i.e. the output file of the
<code>tree.detection.single.scan</code> or
<code>tree.detection.multi.scan</code> (here <code>tree.list</code>),
which is introduced in the argument
<strong><code>tree.tls</code></strong>. The plots to be 