Combining TanDEM-X and GEDI Data For Mapping Forest Structure Parameter Dynamics

Abstract

The synergy of TanDEM-X interferometric data with GEDI lidar full waveform measurements for large-scale forest mapping has been addressed in a number of studies in the last years. In a number of studies, the GEDI lidar full waveforms have been used to approximate the TanDEM-X X-band radar vertical reflectivity function (e.g. the vertical distribution of scatterers) in order to enable the inversion of single-pol single-baseline TanDEM-X datasets. This allows the generation of continuous high-resolution forest height maps at large and global scales without the need for external information about the underlying topography, including a forest height map derived from the combination of TanDEM-X and GEDI data over the whole Brazilian Amazon (including more than 12,000 TanDEM-X scenes and 250 million GEDI lidar measurements). More recently, the low penetration capability at X-band and the high spatial resolution of TanDEM-X have been explored to characterize horizontal forest structure. From the spatial variability of the interferometric phase center it is possible to determine the horizontal canopy heterogeneity and/or density on a 1 hectare scale.