A New Method for Temperature/Emissivity Separation from Hyperspectral Thermal Infrared Data

The central problem of temperature and emissivity separation (TES) is, as Realmuto had pointed out, that we obtain N spectral measurements of radiance and need to find N+1 unknowns (N emissivities and one temperature), if the atmospheric perturbations are well corrected for. Thus, one constraint must be found in the retrieval to obtain the realistic solution for the temperature/emissivity separation. A new index called `Downwelling Radiance Residual Index' (DRRI) is proposed to provide this type of constraint. Tests with the simulated hyperspectral thermal infrared (TIR) data sets demonstrate that this new index can provide an accurate and fast Temperature/Emissivity separation.