Effect of scanning angle on vegetation metrics derived from a nationwide Airborne Laser Scanning acquisition

Abstract

The influence of scanning angle on vegetation metrics derived from a large area Airborne Laser Scanning (ALS) data acquisition was evaluated in this study. The ALS data were derived from the ongoing acquisition for the new Swedish Nationwide Elevation Model. To make a comparison of scanning angles, a random selection of 2310 sample plots (0.01 ha in size) was taken from two large forested areas in the north and south of Sweden. Only plots that had ALS data from two different acquisitions on the same day were used: the first scanned at nadir (0 degrees scnning angle) and the second with an absolute scanning angle ranging from 0 degrees to a nominal 20 degrees. For each plot, 32 plot-level vegetation metrics were calculated from the ALS data for each pair of scanning angles. The ALS metrics for each pair were then compared using a nonparametric Wilcoxon signed-rank test. The results indicated that most metrics commonly used in area-based prediction of forest variables were relatively unaffected by high scanning angles, up to 20 degrees. However, the vegetation ratio and the understory ratio from scanning angles greater than 10 degrees were significantly different from those derived from a 0 degrees scanning angle.

Published in

Canadian Journal of Remote Sensing
2013, volume: 39, pages: S152-S173
Publisher: CANADIAN AERONAUTICS SPACE INST

SLU Authors

• Montaghi, Alessandro

  • Department of Forest Resource Management, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Earth Observation

Publication identifier

• DOI: https://doi.org/10.5589/m13-052

Permanent link to this page (URI)

https://res.slu.se/id/publ/55289