TIRS band data can be converted from spectral radiance to brightness temperature using the thermal constants provided in the metadata file:
where:
\( T \) = At-satellite brightness temperature (K)
\( { L\lambda } \) = TOA spectral radiance (Watts/( m2 srad μm))
\( K1 \) = Band-specific thermal conversion constant from the metadata (K1_CONSTANT_BAND_x, where x is the band number, 10 or 11)
\( K2 \) = Band-specific thermal conversion constant from the metadata (K2_CONSTANT_BAND_x, where x is the band number, 10 or 11)
library(rLandsat8)
setwd("~/Downloads")
product <- "LC82040322013219LGN00"
l <- ReadLandsat8(product)
btemp <- ToAtSatelliteBrightnessTemperature(l, band="tirs1")