Validation of physical unmixing model in the radiative domain

This paper presents a validation of physical based unmixing model in the radiative domain using airborne thermal hyperspectral data and ground truth measurements. The validation results show that if the optical property of a given surface element largely differs from the other mixed elements, it becomes more difficult to retrieve its proper characteristics, particularly when its size is small. The obtained results also show that in the case of flat and homogenous surfaces, there is a linear mixing of the emissivity but not of the temperature. In general, the accuracy of the physical unmixing model is degraded as the mixing proportion is increased (more than two materials) and the ratio of the considered elementary surface by the equivalent surface is reduced.