Professor Gu’s research has focused on quantitative remote sensing, optical satellite sensor calibration, aerosol remote sensing, and the demonstration and application of Earth observation systems, with particular emphasis on the engineering application of remote sensing data to national strategic needs. As Chief Designer of the Application System for the National Major Science and Technology Special Project “High-Resolution Earth Observation System,” Leader of the Requirements and Applications Group for the “National Spatial Infrastructure Construction Medium- and Long-Term Development Plan,” and Chief Scientist of a National 973 Programme project on multi-scale aerosol comprehensive observation and spatio-temporal distribution, he has contributed to the standardisation, engineering development, and operational application of quantitative remote sensing technologies in China. His work has also included participation in the drafting working group for the GEO Decadal (2016–2025) Development Plan and service as Deputy Leader of the Overall Expert Group for the National Key Research and Development Programme on Earth Observation and Navigation. He has authored 521 peer-reviewed publications and 14 monographs and holds 53 authorised invention patents. His contributions have been recognised through three National Science and Technology Progress Awards (Second Prize), four Provincial/Ministerial First Prizes, and four academic society awards. He has also led the drafting and promulgation of three national standards. Through sustained research, leadership of major Earth observation programmes, and international scientific collaboration, Professor Gu has contributed to connecting advances in remote sensing science with the development of spatial information infrastructure, environmental monitoring, and Earth observation applications in China and internationally.