Direction discretization for radiative transfer modeling: An introduction to the new direction model of dart

Many radiative transfer (RT) models combine exact kernel and discrete ordinate techniques for solving the transport equation. They discretize the 4π space into a finite number of angular sectors, with directions along which radiation propagates. They can be more or fewer and equally spaced or not. RT model improvement is usually focused on 3D landscapes simulation and RT mathematical modeling. The angular variable Ω discretization is a much less addressed problem, although it can strongly influence the simulation of satellite signals, especially with small numbers of discrete directions. Here, we present a new Ω discretization that improves the accuracy of simulated result.