An experimental study to address issues encountered in the determination of surface bi-directional reflectivity and emissivity of materials [3–5µm] region has been conducted in outdoors conditions. The measurement protocol included radiometric infrared camera acquisitions in both [3–5µm] (band-2) and [8-14µm] (band-3). The band-2 bi-directional reflectivity is obtained from a sequence of sunlit and shade measurements. Best results are found with measurements relative to a diffuse aluminum reflector. Direct inversion of band-2 radiometric signal is unstable. A multi-temporal method is introduced and the slope of the linear regression is the searched emisssivity. A detailed analysis is conducted to assess the impact of different sources of systematic errors. The proposed method is found to have a good potential with an estimated measurement error in the range of 2%.
© 2004 Optical Society of America
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