In-scene atmospheric correction of hyperspectral thermal infrared images with nadir, horizontal, and oblique view angles

Atmospheric corrections for hyperspectral thermal images acquired with nadir, horizontal, and oblique views have typically relied on atmospheric modelling software, such as Moderate Resolution Atmospheric Transmission (MODTRAN), to estimate atmospheric parameters. Data-only corrections, which require only information from the scene, are more versatile and less labour intensive, but do not yet seem to have been applied to horizontal and oblique views. Here, we apply, and modify where necessary, one published data-only algorithm (in-scene atmospheric correction (ISAC)) to nadir, horizontal, and slanted views (The Aerospace Corporation's Spatially Enhanced Broadband Array Spectrograph System (SEBASS) and Telops Inc.'s Hyper-Cam data sets) to assess the applicability for different viewing geometries. We find that it successfully retrieves characteristic mineralogical emissivity spectra in scenes taken from all geometries. We also discuss additional corrections to the Hyper-Cam data set to correct for instrumental artefacts.