Accurate spaceborne waveform simulation in heterogeneous forests using small-footprint airborne LiDAR point clouds - Yi Li; Guangjian Yan; Weihua Li; Donghui Xie; Hailan Jiang; Linyuan Li; Jianbo Qi; Ronghai Hu; Xihan Mu; Xiao Chen; Shanshan Wei; Hao Tang (ISPRS Journal of Photogrammetry and Remote Sensing, 2025)