A model based on spectral invariant theory for correcting topographic effects on vegetation canopy reflectance - Weihua Li; Guangjian Yan; Jun Geng; Yuhan Guo; Tian Xie; Xihan Mu; Donghui Xie; Jean-Louis Roujean; Guoqing Zhou; Jean-Philippe Gastellu-Etchegorry (Remote Sensing of Environment, 2025)