Multi Temporal Regression Method For Mid Infrared [3-5 Mu M] Emissivity Outdoor Measurements

An experimental study to address issues encountered in the determination of surface bi-directional reflectivity and emissivity of materials [3-5 mum] region has been conducted in outdoors conditions. The measurement protocol included radiometric infrared camera acquisitions in both [3-5 mum] ( band- 2) and [8-14 mum] (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 multitemporal 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%. (C) 2004 Optical Society of America.