# An Overview of the Applications of Earth Observation Satellite Data: Impacts and Future Trends
## 3 Results
### Subject Analysis
Vegetation monitoring is an important focus of EO, and the growth of vegetation reflects the condition of the  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**All Earth Observation** & \multicolumn{2}{c}{**Sentinel**} & \multicolumn{2}{c}{**Landsat**} & \multicolumn{2}{c}{**MODIS**} & \multicolumn{2}{c}{**Gaofen**} & \multicolumn{2}{c}{**WorldView**} \\ \hline
**Cluster (Size)** & **Mean** & **Cluster (Size)** & **Mean** & **Cluster (Size)** & **Mean** & **Cluster (Size)** & **Mean** & **Cluster (Size)** & **Mean** & **Cluster (Size)** & **Mean** \\ \hline Land-cover & \multirow{3}{*}{1995} & Deep learning & \multirow{3}{*}{2016} & Spectral & \multirow{3}{*}{2003} & Penology & \multirow{3}{*}{2011} & Convolutional & \multirow{3}{*}{2016} & OBIA & \multirow{3}{*}{(93)} & \multirow{3}{*}{2011} \\ (427) & & & & analysis & & & & & (78) & & \\ \cline{4-9} Great Lakes & \multirow{3}{*}{1988} & Leaf area & \multirow{3}{*}{2009} & Landsat & \multirow{3}{*}{2011} & Aerosols & \multirow{3}{*}{2003} & Cloud & \multirow{3}{*}{2015} & WorldView-3 & \\ (395) & & & index (115) & & & & & & (42) & & \\ \cline{4-9} Random forest & \multirow{3}{*}{2014} & InSAR & \multirow{3}{*}{2014} & Habitat & \multirow{3}{*}{1994} & Land surface & \multirow{3}{*}{2012} & Gaofen-3 & Pan- & \multirow{3}{*}{2016} \\ (370) & & & & & & & & (186) & & (54) & \\ \cline{4-9} Evaportrans- & \multirow{3}{*}{2005} & Random forest & \multirow{3}{*}{2016} & Savanna & \multirow{3}{*}{1999} & AOD & \multirow{3}{*}{2009} & Ship detection & \multirow{3}{*}{2016} & Bathymetry & \multirow{3}{*}{2012} \\ (329) & & & & & & & & (71) & & (89) & \\ \cline{4-9} Landsat & \multirow{3}{*}{2011} & Deforestation & \multirow{3}{*}{2013} & Landscape & \multirow{3}{*}{1988} & BRDF * & \multirow{3}{*}{1998} & Satellite image & \multirow{3}{*}{2014} & Indigenous & \multirow{3}{*}{2013} \\ (280) & & & & & & & & (69) & & (37) & \\ \cline{4-9} Aerosols & \multirow{3}{*}{2002} & Sentinel-1 & \multirow{3}{*}{2016} & Google Earth & \multirow{3}{*}{2012} & Engine & \multirow{3}{*}{2012} & Object-based & \multirow{3}{*}{2014} & Deep learning & \multirow{3}{*}{2016} \\ (222) & & & & & & & & (144) & & (34) & & (45) & \\ \cline{4-9} Phenology & \multirow{3}{*}{2010} & Flood & \multirow{3}{*}{2010} & Change & \multirow{3}{*}{2016} & Climate & Information & \multirow{3}{*}{1993} & Digital surface & \multirow{3}{*}{2012} \\ (177) & & & & & & & & & model & 2012 \\ \cline{4-9} Land surface & \multirow{3}{*}{2013} & Soil moisture & \multirow{3}{*}{2013} & PM 2.5 & \multirow{3}{*}{1980} & Puration & \multirow{3}{*}{2009} & Urban areas & \multirow{3}{*}{2007} \\ (167) & & & & & & & & (128) & & & (35) & \\ \cline{4-9} Biomass burning (168) & & & & & & & & & & & \\ \cline  
land and ecosystems [80,81]. Currently, popular satellite missions (e.g., Landsat, MODIS, and Sentinel) have wavebands specifically designed for observing vegetation cover or vegetation types. The accurate estimation of area in land use-land cover studies is essential to studies of global environmental change. As shown in Table S5, some representative keywords appear repeatedly. These keywords indicate the aspects to which EO data are applied and include classification, model, vegetation, algorithm, validation, area, climate change, etc. There is a slight difference between satellites from the perspective of which keywords appear most frequently. Vegetation, climate, and land cover are the most common focuses of research that reference satellite data. The ability to provide time-series of data is one of the essential characteristics of EO satellite data. Changes in the Earth's system and future environmental changes can be analyzed effectively using long time-series of satellite data. RF is a popular machine learning classifier and is widely used for processing images. The use of satellite scenes of the same target from multiple sources helps to produce high-quality information.