Forest canopy gap fraction from terrestrial laser scanning

Danson, FM; Hetherington, D; Morsdorf, F; et, al

Abstract

A terrestrial laser scanner (TLS) was used to measure
canopy directional gap fraction distribution in forest stands
in the Swiss National Park, eastern Switzerland. A scanner model
was derived to determine the expected number of laser shots in
all directions, and these data were compared with the measured
number of laser hits to determine directional gap fraction at
eight sampling points. Directional gap fraction distributions were
determined from digital hemispherical photographs recorded at
the same sampling locations in the forest, and these data were compared
with distributions computed from the laser scanner data.
The results showed that the measured directional gap fraction
distributions were similar for both hemispherical photography
and TLS data with a high degree of precision in the area of overlap
of orthogonal laser scans. Analysis of hemispherical photography
to determine canopy gap fraction normally requires some manual
data processing; laser scanners offer semiautomatic measurement
of directional gap fraction distribution plus additional threedimensional
information about tree height, gap size, and foliage
distributions.

Citation

Danson, F., Hetherington, D., Morsdorf, F., & et, A. (2007). Forest canopy gap fraction from terrestrial laser scanning. IEEE Geoscience and Remote Sensing Letters, 4(1), 157-160. https://doi.org/10.1109/LGRS.2006.887064

• Journal Article Type: Article
• Publication Date: Jan 1, 2007
• Deposit Date: Nov 23, 2009
• Publicly Available Date: Nov 23, 2009
• Journal: IEEE Geoscience and Remote Sensing Letters
• Print ISSN: 1545-598X
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 4
• Issue: 1
• Pages: 157-160
• DOI: https://doi.org/10.1109/LGRS.2006.887064
• Keywords: Directional gap fraction, forest structure, hemispherical; photography, terrestrial laser scanner (TLS)
• Publisher URL: http://dx.doi.org/10.1109/LGRS.2006.887064