Polarized adding method of discrete ordinate approximation for ultraviolet-visible and near-infrared radiative transfer

The polarization characteristics of atmospheric scattering are important for planetary studies and should not be ignored in radiative transfer simulations. In this study, what we believe to be a new vector radiative transfer model called the polarized adding method of discrete ordinate approximation (POLDDA) is proposed for use in remote sensing applications for ultraviolet-visible and near-infrared spectra. The single-layer radiative transfer process and inhomogeneous multi-layer connection are solved using the discrete ordinate method (DOM) and adding methods, respectively. By combining the advantages of DOM and the adding method, the Stokes vector (including the I-, Q-, U-, and V-components) calculated using the supposed new method conforms to the results of PolRadtran/RT3, whether in a Rayleigh scattering atmosphere or a water cloud-dominated case. Moreover, the relative root-mean-square error (RMSE) values of the Stokes vector for the test cases between MYSTIC and the new method or RT3 demonstrate the accuracy of the proposed method. In addition, the apparently new method has a higher computational efficiency than RT3, particularly for an atmosphere with a large scattering optical depth. Unlike RT3, the computation time of the proposed method does not increase with the optical depth of each layer.