摘要
Extrinsic information,from satellite observations and the outputs of spatial models,and intrinsic information,from ground observations and spatial sampling,provide two different but complementary streams of information about the Earth’s surface.These extrinsic and intrinsic informations are indispensable for the modelling of the Earth’s surface systems along with an appropriate method for integrating these two kinds of information.Building on this idea,the fundamental theorem for Earth’s surface system modeling(FTESM)was proposed,from which several corollaries have been deduced,corresponding to spatial interpolation,spatial upscaling,spatial downscaling,data fusion and model-data assimilation,respectively(Yue et al.,2016).
