Fig. 1
a, b Relationship between temperature and spectral radiance based on the Planck equation. c Relationship between fraction of high-temperature portion within a pixel (%) and spectral radiance at 1.63 µm and 10.8 µm. The high-temperature portion (T2) and the background (T1) are assumed to be 800 °C and 20 °C, respectively. d Schematic illustration of the relationship between pixel size of the SGLI and a small to medium lava flow. e Schematic illustration showing the relationship between pixel size of the MODIS and Himawari-8 and a small to medium lava flow