Atmospheric corrections of passive microwave data for estimating land surface temperature

National Natural Science Foundation of China 41101332 41231170；Institute of Geographic Science and Nature Resources Research (IGSNRR)；Chinese Academy of Sciences (CAS) 2012SJ004Quantitative analysis <span class="hitHilite">of</span> the <span class="hitHilite">atmospheric</span> effects on observations made by the Advanced <span class="hitHilite">Microwave</span> Scanning Radiometer-Earth Observing System (AMSR-E) has been performed. The differences between observed brightness temperatures at the top <span class="hitHilite">of</span> the atmosphere and at the bottom <span class="hitHilite">of</span> the atmosphere were analyzed using a database <span class="hitHilite">of</span> simulated observations, which were configured to replicate AMSR-E data. The differences between observed brightness temperatures at the top <span class="hitHilite">of</span> the atmosphere and land surface-emitted brightness temperatures were also computed. Quantitative results show that the atmosphere has different effects on brightness temperatures in different AMSR-E channels. <span class="hitHilite">Atmospheric</span> effects can be neglected at 6.925 and 10.65 GHz, when the standard deviation is less than 1 K. However, at other frequencies and polarizations, <span class="hitHilite">atmospheric</span> effects on observations should not be neglected. An <span class="hitHilite">atmospheric</span> correction algorithm was developed at 18.7 GHz vertical polarization, based on the classic split-window algorithm used in thermal remote sensing. Land surface emission can be estimated with RMSE = 0.99 K using the proposed method. Using the known land surface emissivity, Land Surface Temperature (LST) can be retrieved. The RMSE <span class="hitHilite">of</span> retrieved LST is 1.17 K using the simulated data