2381/28885
Ehsan Khalefa
Ehsan
Khalefa
Izak P. J. Smit
Izak P. J.
Smit
Alecia Nickless
Alecia
Nickless
Sally Archibald
Sally
Archibald
Alexis Comber
Alexis
Comber
Heiko Balzter
Heiko
Balzter
Retrieval of savanna vegetation canopy height from ICESat-GLAS spaceborne LiDAR with terrain correction
University of Leicester
2014
Science & Technology
Physical Sciences
Technology
Geochemistry & Geophysics
Engineering, Electrical & Electronic
Remote Sensing
Engineering
ENGINEERING, ELECTRICAL & ELECTRONIC
GEOCHEMISTRY & GEOPHYSICS
REMOTE SENSING
Canopy height
Geoscience Laser Altimeter System (GLAS)
Ice Cloud and land Elevation Satellite (ICESat)
Kruger National Park
light detection and ranging (LiDAR)
savanna
terrain correction
ABOVEGROUND BIOMASS
SATELLITE LIDAR
AIRBORNE
VOLUME
QUEBEC
2014-05-30 15:55:55
Journal contribution
https://figshare.le.ac.uk/articles/journal_contribution/Retrieval_of_savanna_vegetation_canopy_height_from_ICESat-GLAS_spaceborne_LiDAR_with_terrain_correction/10143950
Light detection and ranging (LiDAR) remote sensing enables accurate estimation and monitoring of vegetation structural properties. Airborne and spaceborne LiDAR is known to provide reliable information on terrain elevation and forest canopy height over closed forests. However, it has rarely been used to characterize savannas, which have a complex structure of trees coexisting with grasses. This letter presents the first validation of spaceborne Ice Cloud and land Elevation Satellite Geoscience Laser Altimeter System (GLAS) full-waveform data to retrieve savanna vegetation canopy height that uses field data specifically collected within the GLAS footprints. Two methods were explored in the Kruger National Park, South Africa: one based on the Level 2 Global Land Surface Altimetry Data product and the other using Level 1A Global Altimetry Data (GLA01) with terrain correction. Both methods use Gaussian decomposition of the full waveform. Airborne LiDAR (AL) was also used to quantify terrain variability (slope) and canopy height within the GLAS footprints. The canopy height retrievals were validated with field observations in 23 GLAS footprints and show that the direct method works well over flat areas (Pearson correlation coefficient r = 0.70, p<0.01, and n = 8 for GLA01) and moderate slopes (r = 0.68, p<0.05, and n = 9 for GLA01). Over steep slopes in the footprint, however, the retrievals showed no significant correlation and required a statistical correction method to remove the effect of terrain variability on the waveform extent. This method improved the estimation accuracy of maximum vegetation height with correlations (R[superscript 2] = 0.93, p<0.05, and n = 6 using the terrain index (g) generated from AL data and R[superscript 2] = 0.91, p<0.05, and n = 6 using the GLAS returned waveform width parameter). The results suggest that GLAS can provide savanna canopy height estimations in complex tree/grass plant communities.