Testing the Application of Terrestrial Laser Scanning to Measure Forest Canopy Gap Fraction

Remote Sensing

F. Alberto Ramirez¹  Richard P. Armitage² 

[1]School of Environment and Life Sciences, University of Salford, Salford M5 4WT, UK

关键词: terrestrial laser scanning;    forest canopy gap fraction;    intensity data;   

DOI  :  10.3390/rs5063037

来源: mdpi

【 摘 要 】

Terrestrial laser scanners (TLS) have the potential to revolutionise measurement of the three-dimensional structure of vegetation canopies for applications in ecology, hydrology and climate change. This potential has been the subject of recent research that has attempted to measure forest biophysical variables from TLS data, and make comparisons with two-dimensional data from hemispherical photography. This research presents a systematic comparison between forest canopy gap fraction estimates derived from TLS measurements and hemispherical photography. The TLS datasets used in the research were obtained between April 2008 and March 2009 at Delamere Forest, Cheshire, UK. The analysis of canopy gap fraction estimates derived from TLS data highlighted the repeatability and consistency of the measurements in comparison with those from coincident hemispherical photographs. The comparison also showed that estimates computed considering only the number of hits and misses registered in the TLS datasets were consistently lower than those estimated from hemispherical photographs. To examine this difference, the potential information available in the intensity values recorded by TLS was investigated and a new method developed to estimate canopy gap fraction proposed. The new approach produced gap fractions closer to those estimated from hemispherical photography, but the research also highlighted the limitations of single return TLS data for this application.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland