# An Overview of the Applications of Earth Observation Satellite Data: Impacts and Future Trends
## 3 Results
### Cooperation Network Analysis  
At the institutional level, scientific institutions from China and the United States have dominated research referencing EO satellites (Table S6). In terms of references to the EO satellites discussed in this paper, the top ten scientific institutions in terms of published papers are the Chinese Academy of Sciences (4416), the National Aeronautics and Space Administration (NASA) (2151), the University of Chinese Academy of Sciences (1385), the University of Maryland (1201), Beijing Normal University (985), Wuhan University (851), National Oceanic and Atmospheric Administration (NOAA) (688), the California Institute of Technology (615), the United States Geological Survey (USGS) (595), and the University of Wisconsin System (507). More papers referencing EO satellites have been written by authors at Chinese scientific institutions than by those at institutions in other countries. However, the average time for scientific institutions in China to conduct research is generally posterior to that of U.S. institutions. In relation to the top five EO satellites, scientific institutions in China and the United States still dominate the published papers. The largest number of papers originated at the Chinese Academy of Sciences. Wuhan University, the University of Chinese Academy of Sciences, NASA, the University of Maryland and NOAA are also significant institutions in terms of published research referencing EO satellites. These institutions have thus promoted the application of EO satellite data.  
At the national level, the United States and China constitute the center of research using EO satellite data (Table S7 and Figure 4). The top ten countries are the United States (14,003), China (11,165), Germany (2960), Canada (2760), India (2743), the United Kingdom (2660), France (2503), Italy (2489), Australia (1622), and Japan (1585) (including duplicates). The number of published papers that reference EO satellites data is highly concentrated in the United States and China, with these two countries accounting for 25,168 papers (including duplicates), which is 39.17% of the total. In terms of references to the top five EO satellites, the United States and China also dominate the research and authors from these countries have had more related articles published than those from other countries (Table S7).  
The Nature Index tracks the countries and institutions that dominate high-quality research in the natural sciences. The index is based on the number of publications in 82 prestigious scientific journals selected by leading researchers [82]. The Nature Index can be used to determine which countries and institutions make a significant contribution to natural sciences research. According to the Nature Index, the United States and China again have the largest number of scientific institutions (2637 and 1485, respectively) featuring in these selected journals as well as the most published papers (29,207 and 19,084, respectively, in 2020). The amount of research conducted by Chinese scientists has increased rapidly in the past few years, but this increase is gradually slowing down. This explains why the average time required by Chinese scientists to carry out research based on EO satellite data is posterior to that of scientists in the United States. Among individual institutions,the Chinese Academy of Sciences has maintained its seemingly unassailable lead (with 5776 papers in 2020).  
It is also clear that the countries that produce EO satellite data and their partner countries receive priority in gaining access to the data, whereas scientists in other countries will have more difficulty. For example, in terms of publications referencing Gaofen satellites, the top ten institutions are all from China. In this respect, China holds an unassailable lead at the national level, with 415 papers (78.90% of the total) referencing Gaofen satellites. Open access to EO satellite data is important to the development of remote sensing applications and the promotion of satellite missions.