The article Ibrutinib structured as follows: satellite data, emissivity library and ground-measured data are described in Section 2. Section 3 introduces the radiative transfer simulation based on MODTRAN, variable selection and the ANN training and retrieval method. The sensitivity analyses were performed to check the impacts of solar illumination, atmospheric profile quantity and spectral emissivity data on the radiative transfer simulation and ANN model in Section 4. In Section 5, results of retrieval and validation are presented. In addition, the statistical characteristic of the simulation database is also shown. Section 6 gives the conclusions.
2.1. MODIS and VIIRS data
The specific spectral bands used in this work include MODIS bands 29, 31, 32 and 33, and VIIRS bands M14, M15 and M16. They have the similar channel characteristics (Table 1). It can be found that MODIS\'s band noise-equivalent temperature difference (NEΔT, 0.05) are better than VIIRS\'s (0.070, 0.072 and 0.091) except MODIS band 33 with NEΔT of 0.25, but VIIRS data have higher spatial resolution of 750 m at nadir in contrast with MODIS 1-km data. The spectral response function of MODIS band 29 is analogous to VIIRS band M14, and those of VIIRS bands M15 and M16 are wider than MODIS bands 31 and 32 (Fig. 1).