1. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 U.S.A., Kejie.Chen@jpl.nasa.gov, Zhen.Liu@jpl.nasa.gov, yuhe.t.song@jpl.nasa.gov
2. Canada Center for Mapping and Earth Observation, Natural Resources Canada, Ottawa, Ontario, Canada K1A 0E4, wanpeng.feng@canada.ca