Reduced χ² statistics for simulated full-mission 30-GHz data. The initial resolution of the noise covariance matrix is N_side = 32 (110′). The uppermost panel represents an idealized simulation, compared with the most accurate (and most expensive to produce) noise covariance matrix. The level of idealization decreases from top to bottom, the lowest panel representing a fully realistic simulation compared against a covariance matrix from production runs.