Photopolarimetric properties of a manmade target over a wide range of measurement directions.

The optical scattering property of a target is the essential signal for passive remote sensing. In this study, we performed the photopolarimetric measurements of a manmade target in the wavelength range of 400-1000 nm over the hemispherical directions using the Northeast Normal University Laboratory Goniospectrometer System (NENULGS). We discussed the influence of the absorption of a polarizer on the measured Stokes parameters, and used the BRF (bidirectional reflectance factor) and BPRF (bidirectional polarized reflectance factor) to characterize the scattering property of our sample at selected wavelengths. These measured BRFs and BPRFs were also compared with the modeled results using a semi-empirical photometric model and a semi-empirical polarimetric model, respectively. Subsequently, the modeled BRFs and BPRFs were used to simulate the degree of linear polarization (DoLP) of a man-made target, which provided a comparison with the measured DoLP. We found that (1) the I parameter reflectance factor (IpRF) can effectively represent the BRF if we considered the absorption of the polarizer, (2) the modeled photopolarimetric results of manmade target were in good agreement with the measurements, and (3) the simulated DoLP of manmade target also provided a good match with the measured DoLP, with an average relative difference of approximately 0.2 for all the selected wavelengths. Our results appeared very promising for proving that the polarimetric measurement is a very effective and useful method for remote sensing applications as well as deepening our understanding of the optical properties of reflected light from the manmade object as ours.