UC Santa Barbara

The third-generation, polar orbiting, TIROS-N series of environmental satellites provides two thermal IR channels for twice-daily monitoring of the Earth's surface. Part of the Advanced Very High Resolution Radiometer (AVHRR), the 3. 8 mu m thermal IR channel was designed to supplement the 11 mu m thermal IR channel in the computation of sea surface temperature by providing corrections for atmospheric water vapor and cloud contamination. Initial examination of the 3. 8 mu m data over land areas, however, revealed differences between them and the 11 mu m data. It is concluded that the 3. 8 mu m channel is also useful for identification of ″hot″ sources. Employing the algorithm of J. Dozier (1981) it is possible to determine the blackbody temperature of these sources and the portions of the 1. 1-km pixels covered by the ″hot″ targets.