I'm working on a project right now and I want to make sure that I get the radiometric corrections perfect and I've heard that thermal bands are different from 1-4. I was told that you can't just use darkest object subtraction or a cos(t) model, but that you have to have a different approach altogether. I'm going to be using LandSat8's TIRS (bands 10,11) to try to discern an estimate of surface temperature. The image that I have is relatively free of cloud cover, but I want to make this image as clean as possible so as to not accidentally calculate the Top of Atmosphere temp. Any help would be awesome!