## 3 Results and Validation  
### Atmospheric Correction Results  
A large number of MHSR data have been used for testing the proposed method to demonstrate its effectiveness. Among these data, two datasets are selected as two examples for demonstrating the spatial and temporal consistency and the capability of different satellite data. Firstly, Figure 4 gives an example of the atmospheric-corrected images for different MHSR images with varied aerosol loadings. The different MHSR images include GF-1/WFV3, GF-1/WFV4, Landsat/OLI, and Sentinel2B/MSI from top to bottom, respectively. In addition, the highly varied aerosol loadings and unevenly distributed aerosols of images in Figure 4 are well corrected; therefore, the example in Figure 4 comprehensively shows the capability for different satellite data and the ability to keep spatial consistency under different atmospheric conditions and even with unevenly distribution of aerosols at arid areas. The parameters of these images are listed in Table 4. Secondly, Figure 5 shows an example of a multi-temporal atmospheric correction of Landsat8/OLI at Tamarasset_INM site with highly different aerosol loadings. The dates of these images are 29 May 2015, 1 December 2016, 19 February 2017, 23 March 2017, and 11 June 2017 from top to bottom, respectively. The parameters of these images are listed in Table 5. The images after atmospheric correction (the right column) are consistent in space and time. The images at 29 May 2015, and 11 June 2017 looks different because the very bright clouds influences the visual details of the two images. However, the uneven distribution of the aerosol is corrected very well, which shows the applicability of the proposed method. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameter** & **Setting** & **Format** & **Source** \\ \hline View zenith angle & 0–30\({}^{\circ}\):5\({}^{\circ}\) & Range: interval & Metadata of MHSR imagery \\ Solar zenith angle & 0–50\({}^{\circ}\):5\({}^{\circ}\) & Range: interval & Metadata of MHSR imagery \\ Relative azimuth angle & 0–180\({}^{\circ}\):10\({}^{\circ}\) & Range: interval & Metadata of MHSR imagery \\ Atmospheric model & Mid-latitude summer, mid-latitude winter, tropical & & Geographic latitude \\ Aerosol model & Desert and continental models & & Land cover from \\  & 0.01, 0.05, 0.1, 0.2, 0.4, 0.8, 1.0, & & FROM-GLC 1 \\ AOD & 1.5, and 2.0. & & \\ Altitude & 0, 100, 200, 500, 1000, 2000, 3000, & & ASTER digital elevation \\  & 4000, and 5000 m & & model ([[http://asterweb.jpl.nasa.gov/gdem.asp](http://asterweb.jpl.nasa.gov/gdem.asp)]([http://asterweb.jpl.nasa.gov/gdem.asp](http://asterweb.jpl.nasa.gov/gdem.asp))) \\ Water vapor & 0.1–5.1: 1 g/cm\({}^{2}\) & Range: interval & MODIS product \\  & Blue: 0–0.2:0.02 & & \\ Surface reflectance & Green: 0–0.4:0.04 & & \\  & Red: 0–0.4:0.04 & Range: interval & \\  & NIR: 0–0.5:0.05 & & \\ Sensor & All the sensors listed in Table 1 & Metadata of MHSR imagery \\ \hline \hline \end{tabular}  
* Land cover from FROM-GLC is cited from [1]. Abbreviations: FROM-GLC, Finer resolution observation and monitoring of global land cover product.  
\end{table} 
Table 3: The settings of 6S’s parameters to create look-up tables (LUTs) for AOD retrieval and atmospheric correction. Figure 4: The atmospheric correction examples for the 4 different categories of MHSR imagery at 2 different AERONET sites. The four examples from top to bottom respectively are **(a,b)** GF-1/WFV3 at Dalanzadgad, **(c,d)** GF-1/WFV4 at Dalanzadgad, **(e,f)** Landsat8/OLI at Tamanarsset_INM, and **(g,h)** Sentinel2B/MSI at Tamanarsset_INM. Each of the 4 examples include two panels. The left column is the true color composite before atmospheric correction and the right column is the true color composite after the atmospheric correction. Figure 5: The atmospheric correction example for multi-temporal Landsat/OLI imagery at Tamarasset_INM site. The left column is the true color composite before atmospheric correction. The right column is the true color composite after atmospheric correction.