Simulations of GaoFen-5 Directional Polarimetric Camera(DPC) Observations Using the Advanced Vector Discrete Ordinate Radiative Transfer Model

In recent years, polarization remote sensing has garnered increasing attention, particularly within the realm of meteorology. To accurately simulate polarization information, the vector discrete-ordinate radiative transfer(VDISORT)model developed earlier by the community is further enhanced to an advanced version(referred to as A-VDISORT)through an improved ocean surface reflection. The Fresnel reflection matrix, which includes wind-generated roughness and shading effects, is served by an ocean bidirectional reflection distribution function(BRDF). The simulation from AVDISORT is compared with SCIATRAN for a Rayleigh scattering atmosphere, and the influence of water-leaving radiance is analyzed by the PSTAR(Polarized System for Transfer of Atmospheric Radiation) model. For GaoFen-5 Directional Polarimetric Camera(DPC) observations with polarization and multi-angle information, clear-sky pixel recognition over the ocean is first carried out. The DPC reflectance of clear conditions is normalized and compared with the observations. It is shown that A-VDISORT has a high simulation accuracy with a bias of –0.0053. The difference between simulation and observation exhibits a standard normal probability distribution function.