Illustration of source of stray light for a single L8 TIRS detector
Illustration of source of stray light for a single TIRS detector. The source of the stray light is within the TIRS interval to the north and south of the detector, but to the east the stray light originates from outside the sensor’s field-of-view (also to the west, though this particular detector is not affected by stray light to the west). For the locations that fall within the FOV, the TIRS scene radiance is used as the stray light radiance. For the locations that fall outside the FOV, the radiances at the edge of the scene are used as a surrogate for the actual source. This assumes that the radiances at the scene edges are roughly correlated to the radiance field outside the FOV. (Gerace and Montanaro, 2017)
See https://www.usgs.gov/land-resources/nli/landsat/landsat-8-oli-and-tirs-… for more information.