Variation in MidIR and LWIR polarimetric imagery due to diurnal and meteorological impacts

Abstract

We present radiometric and polarimetric calibrated imagery recorded in both the mid-wave IR (MidIR) and long wave IR (LWIR) as a function diurnal variation over several multiday periods. We compare differences in polarimetric and conventional thermal imagry for both IR atmospheric transmission windows, i.e., 3-5μm and 8-12 μm regions. Meteorological parameters measured during the study include temperature, relative-humidity, wind-speed/direction, precipitation, and ambient atmospheric IR loading. The two camera systems used in the study differed significantly in design. The LWIR polarimetric sensor utilizes a spinning achromatic retarder and is best suited for static scenes, while the MidIR system is based on a division-of-aperture design and is capable of recording polarimetric imagery of targets that are rapidly moving. Examples of both S0 (conventional thermal) and degree-of-linear polarization (DOLP) imagery are presented and compared.