Second International Conference on Earth Observation for Global Changes : 25-29 May 2009, Chengdu, China / by International Conference on Earth Observation for Global Changes (2nd : 2009 : Chengdu, China), Zhang, Xianfeng, Beijing da xue, University of Waterloo, Chengdu Li Gong Xue Yuan, International Society for Photogrammetry and Remote Sensing., SPIE (Society)