Refined Forest Stand Height Inversion Approach with Spaceborne Repeat-Pass L-Band SAR Interferometry and GEDI Lidar Data

In this paper, we refine a previously developed forest height inversion and mosaicking approach that fuses spaceborne repeat-pass L-band Interferometric Synthetic Aperture Radar (InSAR) and limited lidar data that serve as training samples. In particular, with the availability of spaceborne lidar training samples from NASA's GEDI mission, the previous inversion approach has been adapted to use the sparsely distributed but extensive GEDI lidar data as local training dataset, so that the inverted height estimates are better tuned to match the local lidar data without making assumptions such as constant scene-wide mean behavior of temporal changes. The refined inversion approach is validated at the Howland Forest in Central Maine, US by using JAXA's ALOS/ALOS-2 InSAR data combined with NASA's GEDI lidar data, where the inverted height estimates are compared against NASA's LVIS lidar dataset that serve as ground truth. This refined inversion approach is a potential fusion scheme of the future spaceborne repeat-pass L-band InSAR and lidar missions (e.g. NASA's NISAR and GEDI, JAXA's ALOS-4 and MOLI, and China's LT-1 and TECIS-1).