An improved algorithm to retrieve land surface temperature by GMS 5 data

An algorithm to retrieve land surface temperature by GMS 5/VISSR thermal infrared data is improved, which is called the single time/dual channel split-window algorithm. It adopts the spatial-temporal threshold criterion for cloud detection. From real-time radiosonde data the atmospheric upward and downward radiation and transmissivity are calculated, and the involved emissivity is derived from AVHRR-NDVI. Thus, LST in two thermal infrared channels is retrieved from the RTE (Radiation Transport Equation). Compared with the observed surface temperature (0 cm) at station 54511 and other 43 stations in 2000, LST solutions from RTE are more accurate, with respect to other international algorithms. Sensitivity analysis focuses on the effect of atmospheric attenuation. Based on this algorithm, land surface diurnal cycle in 4 continuous days in the middle and east of Inner Mongolia and the yearly average land surface temperature distribution in pure clear days in East Asia are presented.