Airborne Lidar for Forest Understory Profiles: Validating with Terrestrial Lidar Data
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Date
24/11/2019Item status
Restricted AccessAuthor
Howard, Shiona
Metadata
Abstract
Lidar is an effective active remote sensing instrument with potential for use in forest
management for fire mitigation by accurately measuring vegetation profiles, or foliage density,
height and composition. Lidar is additionally effective at looking for ladder fuels within the
understory over large areas. Terrestrial laser scanners (TLS) are currently used in forestry due
to their high accuracy in measurements. Yet, are unable to measure large areas at once.
Airborne laser scanners (ALS) data could potentially be used in forest management in order to
accurately distinguish understory in mixed canopies in large spatial and remote areas. This
study assesses discrete-returned ALS data against accurate TLS data in a mixed canopy setting
for the detection of understory. ALS data was compared to TLS data in a high voxel resolution
to assess the comparison of leaf area index (LAI) measurements between two data sources. A
Simple Pearson’s correlation of -0.009 showed that there is no relationship between the ALS
and TLS measurements at lower elevations. This lack of agreement between the ALS and TLS
results are potentially due to high occlusion of signals from fire smoke, dense vegetation, tree
trunks or all, along with differences in instrument scan angles. These differences in LAI
measurements, and lack of agreeability, show that the feasibility of using discrete-returned
ALS to accurately measure understory needs to be further studied.