Remote Sensing of Savanna Landscape Structure Using the Geoscience Laser Altimeter System

Savannas cover approximately half of the African land surface and one fifth of the land surface of the world. They are one of the most important, but least understood terrestrial ecosystems. Growing recognition of the importance of the structural component of savanna landscapes has highlighted the need to understand the spatial distribution and temporal dynamics of woody plant structural diversity. Advances in LiDAR technology have enabled three dimensional information of vegetation to be obtained remotely over large areas. However, the use of LiDAR has gained considerable momentum in forested areas and has been limited application to savanna systems. Indeed, the relatively new Ice, Cloud and Elevation Satellite (ICESat) and its sole onboard instrument, the Geoscience Laser Altimeter System (GLAS) has been insufficiently explored for ecological research in these areas. Therefore, the focus of this study is the derivation of structural measurements; canopy height and canopy cover for savanna landscapes to understand the landscape dynamics which has great implications for land management. Results have shown that the savanna structural characteristics such as vegetation height and density can be extracted from waveform parameters. However, savanna vegetation parameter values should be validated against either data from field measurements or data from other optical or/and active sensors. Finally, further investigation will be considered for the entire ICESat-GLAS dataset and more attention will be direct to the effect of terrain slope when retrieving savanna parameters....