Vegetation Height and Underlying Terrain Inversion Using Lutan-1 Spaceborne Bistatic InSAR Data Over Forested Areas

China's first group of L-band interferometric synthetic aperture radar (InSAR) satellites LuTan-1 (LT-1) were successfully launched in 2022. This satellite mission is mainly designed for global digital elevation model (DEM) mapping and rapid surface deformation monitoring. However, the group of satellites also acquired L-band SAR observations in both bistatic and monostatic modes, which presented an opportunity for large-scale forests vertical structure detection and underlying terrain estimation. This article aims at vegetation height and underlying terrain inversion using LT-1 spaceborne bistatic InSAR data with a model-based method. Preliminary cross-validation was performed on the inversion results using terrain and forests height products obtained from spaceborne ICESat-2 products. Both results demonstrated the potential of LT-1 for large-scale vegetation height and underlying terrain inversion. This work will also provide reference for the upcoming TanDEM-L project in studying the regional and global forests parameter estimation using spaceborne bistatic InSAR data.