Schematic representation of the PPMAP iterative process. G012.80 images (at λ₁ = 350 µm and λ₂ = 870 µm) are used for illustrative purpose. In the upper part, we represent how PPMAP distributes “points” in a continuous state space (X, Y, T_dust) that can be divided into finite cells (corresponding to PPMAP pixels, that is, with a size fixed by the user, independent of the pixel size of the observed images). This distribution is then translated into a synthetic continuum emission map through the MBB description, taking into account the PSF of the instruments. Synthetic observations are finally compared to true observations, allowing to update the distribution of points. These iterative steps are repeated until the model converges.