Retrieval of crown closure of moso bamboo forest using unmanned aerial vehicle (UAV) remotely sensed imagery based on geometricoptical model. Extraction of Desertification Information Based on SMA——A Case Study in Mu Us Sandland Estimation of Hunan forest carbon density based on spectral mixture analysis of MODIS data. A study on snow fraction mapping based on hierarchical dynamic endmember spectral mixture analysis (DESMA) over Northern Xinjiang Spectral Mixture Analysis Based on Erf-BP Model and Applied in Extracting Forest Information