Power spectra of destriped dark-bolometer maps using various baseline lengths. The “full” case on the left panel shows the pseudo-C_ℓ power spectrum over the entire map, including the Galactic plane that was masked out while solving for the baseline offsets. Right panel: power spectrum taken over the sky pixels that were considered when solving for the baselines. Shorter baselines clearly suppress noise above ℓ = 20. The 167 ms case shows an elevated residual at ℓ <  100 inside the destriping mask, likely due to the filter’s inability to constrain the solution. The residual at ℓ <  20 is dominated by the irreducible uncertainty set by the Planck scan strategy, and cannot be improved without external information.