Modeling approach is one of the key means of expressing and understanding of remote sensing activities. The remote sensing activity model set discussed herein is with the recognition of the interplay among remote sensing systems, observation targets, and individuals. It is formulated through several layers, of simplification and standardization, across dimensions including information, data, hardware and software, as well as evaluation. The systems engineering approach, derived from the integration of this suite of remote sensing activity models, robustly applied in several projects demonstration, exploring the role of remote sensing systems in practical construction and application, continuously enhancing their maturity, and providing strong support for establishing a system characterized by "Chinese standards, Chinese data, Chinese technology, and Chinese applications" featuring independent innovation.