Abstract: The compositions of fog and haze particles are different. The droplets have the characteristics of large particles, while the composition of haze is complex, and small particles are mostly present. Polarization observation has very great sensitivity to small particles. Based on this characteristic, the polarized radiation characteristics of fog and haze particles are calculated using the vector linearized discrete ordinate radiative transfer(VLIDORT) model. The simulation results can be used to obtain the polarization reflectance of fog and haze particles. In the range of scattering angles of 125$^\circ$ to 150$^\circ$, the polarization reflectance of fog and haze particles varies significantly with the scattering angle distribution. By taking advantage of the radiation characteristics of fog and haze particles, fog and haze have been distinguished based on the polarization and directionality of the earth's reflectances(POLDER)data on March 11, 2008. The distinguished results were compared with moderate-resolution imaging spectroradiometer (MODIS) images and ground station observation data to verify the effectiveness of the algorithm. It is believed that the alogorithm has great reference value and scientific significance for China's GF-5 of directional polarimetric camera(DPC) remote sensing data.

Key words: atmospheric optics, haze particles, vector radiation transmission, distinguishing algorithm