2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/228476We develop practical schemes for the measurement of the covariance matrix for intrinsic angular-momentum variables in quantum optics. We particularize this approach to two-beam polarimetry and interferometry, as well as to ensembles of two-level atoms interacting with classical fields. We show the practical advantages of noisy simultaneous measurements.8 pages, 5 figures. References added and minor changes. Final versionQuantum Physicstext