Results of retrievals using KLIP, comparing each the cases of computing the likelihood using the full covariance matrix (blue), the diagonal elements only (yellow) and using truly Gaussian scattered data (red). (a) Posterior distributions for retrievals from KLIP. Contours are plotted for 2D Gaussian 1, 2 and 3σ levels, corresponding to 36%, 86% and 99% volume regions, and the ground truth value is marked in black. The text labels correspond to the retrieval including the covariance matrix. (b) Median spectrum for the KLIP retrieval with covariance, as well as for the Gaussian (yellow) and noise free cases (green). (c) P–T profiles for KLIP, Gaussian, and noise-free retrievals. The shaded region indicates the 68% confidence region for the retrieved profile.