海面油膜的偏振反射特性仿真实验

To provide a theoretical basis for identification and detection of oil spill pollution on the sea surface, based on the polarization reflection coefficient of Fresnel reflection formula and combined with polarization bidirectional reflectivity factor and probability density distribution function of rough sea surface, a perfect pBRDF model was established. Then the polarization reflection distribution function of sea water and oil film was simulated under different solar incident angles, different detector observation angles and different sea surface wind speed and wind directions. The results show that, firstly, P-polarization reflectance reaches 1.0×10^-5 and 2.5×10^-5 respectively when the solar zenith angle of seawater and oil film is 53° and 56°. S-polarized reflectance increases with the increase of the solar zenith angle. Moreover, the higher sea surface wind speed is, the smaller peak value of polarization reflectance is. Additionally, wind direction only changes spatial position of pBRDF. Finally, the spatial distribution of linear polarization degree between seawater and oil film is obviously different. Experiment platform was set up with the camera working at 40°. The conclusion is obtained that the linear polarization of seawater and oil film is between 0.2-0.4 and 0.5-0.7, respectively. It also shows that using polarization detection to obtain the polarization degree and polarization angle of the target scene can improve the image quality.