Estimating tree stem density and diameter distribution in single-scan terrestrial laser measurements of field plots: a simulation study

ABSTRACT

The single-scan setup of terrestrial laser scanning of a forest field plot has advantages compared to the multi-scan setup: the speed of operation and that there is no need of a co-registration of the different scans. However in a single-scan setup some of the trees are shaded by others and therefore not detected in the scan. A field inventory solution must take this fact into account. This simulation study shows how different plot sizes and tree stand densities influence the stem visibility giving nonlinear effects especially for large trees and high stem numbers. These effects can be counteracted by using an edge or center stem point detection criteria when analyzing the results or by weighting the detected trees by their visibility. It is shown that the stem density and diameter distribution can be estimated from the visible areas of the plot in case the stem positions are Poisson distributed.

KEYWORDS:

• Terrestrial laser scanning
• ground-based lider
• single scan
• simulation
• stem visibility
• stem density
• diameter distribution
• field plot

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Kenneth Olofsson http://orcid.org/0000-0002-2836-2316

Håkan Olsson http://orcid.org/0000-0002-3476-1401

Additional information

Funding

This study was financed by the ÅForsk foundation and the Advanced SAR project of the European Community's Seventh Framework Programme ([FP7/2007-2013]) under grant agreement no 606971.