2024-03-29T01:35:06Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/464202018-06-25T08:48:30Zcom_10261_37com_10261_4col_10261_290
Planck early results. V. The Low Frequency Instrument data processing
Zacchei, A.
López-Caniego, M.
Barreiro, R. Belén
Curto, Andrés
Diego, José María
Herranz, D.
Martínez-González, Enrique
Vielva, P.
Methods: data analysis
Cosmic background radiation
Cosmology: observations
Surveys
19 páginas, 18 figuras, 3 tablas.-- et al.
We describe the processing of data from the Low Frequency Instrument (LFI) used in production of the Planck Early Release Compact Source Catalogue (ERCSC). In particular, we discuss the steps involved in reducing the data from telemetry packets to cleaned, calibrated, time-ordered data (TOD) and frequency maps. Data are continuously calibrated using the modulation of the temperature of the cosmic microwave background radiation induced by the motion of the spacecraft. Noise properties are estimated from TOD from which the sky signal has been removed using a generalized least square map-making algorithm. Measured 1/f noise knee-frequencies range from ~100 mHz at 30 GHz to a few tens of mHz at 70GHz. 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 ≈−10dB level using Jupiter transits, which are also used for geometrical calibration of the focal plane.
This work was supported by the Academy of Finland grants 121703 and 121962.
Peer reviewed
2012-03-01T08:56:33Z
2012-03-01T08:56:33Z
2011-12
artículo
http://purl.org/coar/resource_type/c_6501
Astronomy and Astrophysics 536: A5 (2011)
0004-6361
http://hdl.handle.net/10261/46420
10.1051/0004-6361/201116484
1432-0746
en
http://dx.doi.org/10.1051/0004-6361/201116484
open
EDP Sciences