Recent advances in temperature-emissivity separation algorithms

This paper presents recent advances in temperature emissivity separation. The ARTEMISS (Automatic Retrieval of Temperature and Emissivity using Spectral Smoothness) method was developed over the last 10 years to retrieve temperature, emissivity and associated uncertainties from data collected with hyper-spectral imaging spectrometers. Numerous improvements have been made to speed up the algorithm and create better results. In particular, new selection methods to find blackbody-like pixels led to better estimates of transmission and path radiances. New methods to select the best atmosphere, based on transmission and path radiance, narrow down the number of possible solutions. A new multi-dimensional fitting method based on the AMOEBA algorithm made it possible to include changes on the down-welling radiance for airborne sensors, e.g. from clouds and from transmission through sub-visible cirrus clouds.