Successful PhD Defence: Xiao Liu Advances Remote Sensing of Forest Vertical Structure

Successful PhD Defence: Xiao Liu Advances Remote Sensing of Forest Vertical Structure

We warmly congratulate Dr. Xiao Liu on the successful defence of his doctoral dissertation at TU Dresden.

In his thesis, "Remote Sensing the Third Dimension of Forests with Active Sensors"  (Link), Xiao developed innovative methods to monitor the three-dimensional structure of forests using state-of-the-art active remote sensing technologies. His research combined observations from NASA's GEDI spaceborne lidar mission, ESA's Sentinel-1 radar mission, and airborne SAR tomography (TomoSAR) to improve the quantification of forest structure and above-ground biomass across temperate and tropical forests.

A central contribution of the dissertation is the development of novel approaches to monitor changes in forest canopy structure over time. Using multi-temporal GEDI observations, Xiao demonstrated widespread declines in overstorey canopy cover and simultaneous increases in understorey vegetation in protected Central European forests following recent disturbance events. His work further investigated how seasonal changes observed by GEDI relate to Sentinel-1 radar backscatter and demonstrated the potential of combining GEDI and TomoSAR observations to estimate forest height, above-ground biomass, and their vertical distribution in tropical forests.

The dissertation contributes important methodological advances for monitoring forest ecosystems in three dimensions and provides valuable insights into how forests respond to environmental change. The results are highly relevant for biodiversity monitoring, carbon accounting, and understanding forest resilience under climate change.

During his PhD, Xiao published several high-quality scientific papers in leading international journals, reflecting the impact of his research on the remote sensing community.

The research was supported by a China Scholarship Council (CSC) PhD scholarship and the EU Horizon 2020 EarthBridge project.

We congratulate Dr. Xiao Liu on this outstanding achievement and wish him every success in his future scientific career.