Planck 2013 results. II. Low Frequency Instrument data processing
Planck Collaboration, N. Aghanim, C. Armitage-Caplan, M. Arnaud, M. Ashdown, F. Atrio-Barandela, J. Aumont, C. Baccigalupi, A. J. Banday, R. B. Barreiro, E. Battaner, K. Benabed, A. Benoît, A. Benoit-Lévy, J. -P. Bernard, M. Bersanelli, P. Bielewicz, J. Bobin, J. J. Bock, A. Bonaldi, L. Bonavera, J. R. Bond, J. Borrill, F. R. Bouchet, M. Bridges, M. Bucher, C. Burigana, R. C. Butler, B. Cappellini, J. -F. Cardoso, A. Catalano, A. Chamballu, X. Chen, L. -Y Chiang, P. R. Christensen, S. Church, S. Colombi, L. P. L. Colombo, B. P. Crill, M. Cruz, A. Curto, F. Cuttaia, L. Danese, R. D. Davies, R. J. Davis, P. de Bernardis, A. de Rosa, G. de Zotti, J. Delabrouille, C. Dickinson, J. M. Diego, H. Dole, S. Donzelli, O. Doré, M. Douspis, X. Dupac, G. Efstathiou, T. A. Enßlin, H. K. Eriksen, M. C. Falvella, F. Finelli, O. Forni, M. Frailis, E. Franceschi, T. C. Gaier, S. Galeotta, K. Ganga, M. Giard, G. Giardino, Y. Giraud-Héraud, E. Gjerløw, J. González-Nuevo, K. M. Górski, S. Gratton, A. Gregorio, A. Gruppuso, F. K. Hansen, D. Hanson, D. Harrison, S. Henrot-Versillé, C. Hernández-Monteagudo, D. Herranz, S. R. Hildebrandt, E. Hivon, M. Hobson, W. A. Holmes, A. Hornstrup, W. Hovest, K. M. Huffenberger, A. H. Jaffe, T. R. Jaffe, J. Jewell, W. C. Jones, M. Juvela, P. Kangaslahti, E. Keihänen, R. Keskitalo, K. Kiiveri, T. S. Kisner, J. Knoche, L. Knox, M. Kunz, H. Kurki-Suonio, G. Lagache, A. Lähteenmäki, J. -M. Lamarre, A. Lasenby, M. Lattanzi, R. J. Laureijs, C. R. Lawrence, S. Leach, J. P. Leahy, R. Leonardi, J. Lesgourgues, M. Liguori, P. B. Lilje, M. Linden-Vørnle, V. Lindholm, M. López-Caniego, P. M. Lubin, J. F. Macías-Pérez, G. Maggio, D. Maino, N. Mandolesi, M. Maris, D. J. Marshall, P. G. Martin, E. Martínez-González, S. Masi, M. Massardi, S. Matarrese, F. Matthai, P. Mazzotta, P. R. Meinhold, A. Melchiorri, L. Mendes, A. Mennella, M. Migliaccio, S. Mitra, A. Moneti, L. Montier, G. Morgante, N. Morisset, D. Mortlock, A. Moss, D. Munshi, P. Naselsky, P. Natoli, C. B. Netterfield, H. U. Nørgaard-Nielsen, D. Novikov, I. Novikov, I. J. O'Dwyer, S. Osborne, F. Paci, L. Pagano, R. Paladini, D. Paoletti, B. Partridge, F. Pasian, G. Patanchon, M. Peel, O. Perdereau, L. Perotto, F. Perrotta, E. Pierpaoli, D. Pietrobon, S. Plaszczynski, P. Platania, E. Pointecouteau, G. Polenta, N. Ponthieu, L. Popa, T. Poutanen, G. W. Pratt, G. Prézeau, S. Prunet, J. -L. Puget, J. P. Rachen, W. T. Reach, R. Rebolo, M. Reinecke, M. Remazeilles, S. Ricciardi, T. Riller, G. Robbers, G. Rocha, C. Rosset, M. Rossetti, G. Roudier, J. A. Rubiño-Martín, B. Rusholme, E. Salerno, M. Sandri, D. Santos, D. Scott, M. D. Seiffert, E. P. S. Shellard, L. D. Spencer, J. -L. Starck, V. Stolyarov, R. Stompor, F. Sureau, D. Sutton, A. -S. Suur-Uski, J. -F. Sygnet, J. A. Tauber, D. Tavagnacco, L. Terenzi, L. Toffolatti, M. Tomasi, M. Tristram, M. Tucci, J. Tuovinen, M. Türler, G. Umana, L. Valenziano, J. Valiviita, B. Van Tent, J. Varis, P. Vielva, F. Villa, N. Vittorio, L. A. Wade, B. D. Wandelt, R. Watson, I. K. Wehus, S. D. M. White, A. Wilkinson, D. Yvon, A. Zacchei, A. Zonca
TL;DR
The Planck Collaboration II paper details the LFI data processing pipeline used to generate calibrated timelines and full-sky maps from the first $15.5$ months of Planck data at $30$, $44$, and $70\rm\,GHz$. It covers Level 1–Level 3 data handling, including ADC non-linearity corrections, GMF demodulation, diode combination, precise pointing reconstruction, and MADAM-based destriping mapmaking with noise priors, plus generation of noise covariance matrices and effective beams from Jupiter transits. The work demonstrates robust instrument performance with calibration uncertainties around $0.6\%$ and systematic effects well below the CMB signal, validated through extensive null tests and half-ring analyses, and supported by comprehensive simulations and power-spectrum measurements that align with the Planck likelihood model. These results establish a solid foundation for cosmological inference from Planck LFI measurements and inform future polarization improvements and beam/foreground characterizations.
Abstract
We describe the data processing pipeline of the Planck Low Frequency Instrument (LFI) data processing centre (DPC) to create and characterize full-sky maps based on the first 15.5 months of operations at 30, 44 and 70 GHz. In particular, we discuss the various steps involved in reducing the data, starting from telemetry packets through to the production of cleaned, calibrated timelines and calibrated frequency maps. Data are continuously calibrated using the modulation induced on the mean temperature of the cosmic microwave background radiation by the proper motion of the spacecraft. Sky signals other than the dipole are removed by an iterative procedure based on simultaneous fitting of calibration parameters and sky maps. Noise properties are estimated from time-ordered data after the sky signal has been removed, using a generalized least square map-making algorithm. A destriping code (Madam) is employed to combine radiometric data and pointing information into sky maps, minimizing the variance of correlated noise. Noise covariance matrices, required to compute statistical uncertainties on LFI and Planck products, are also produced. Main beams are estimated down to the -20 dB level using Jupiter transits, which are also used for the geometrical calibration of the focal plane.