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  • Open Access English
    Authors: 
    Poutanen, T.; Lähteenmäki, A.; León-Tavares, J.; Natoli, P.; Polenta, G.; Falvella, M.C.; Bartlett, J.G.; Smoot, G.F.; Stompor, R.; Bonavera, L.; +174 more
    Publisher: HAL CCSD
    Countries: Denmark, France, France, Italy, Spain, Finland, Finland, Spain, France, Italy ...
    Project: EC | DEISA2 (222919), AKA | Planck-satelliitin datan ... (121962), AKA | Cosmology and the Planck ... (121703)

    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. 19 páginas, 18 figuras, 3 tablas.-- et al. Peer reviewed

Include:
1 Research products, page 1 of 1
  • Open Access English
    Authors: 
    Poutanen, T.; Lähteenmäki, A.; León-Tavares, J.; Natoli, P.; Polenta, G.; Falvella, M.C.; Bartlett, J.G.; Smoot, G.F.; Stompor, R.; Bonavera, L.; +174 more
    Publisher: HAL CCSD
    Countries: Denmark, France, France, Italy, Spain, Finland, Finland, Spain, France, Italy ...
    Project: EC | DEISA2 (222919), AKA | Planck-satelliitin datan ... (121962), AKA | Cosmology and the Planck ... (121703)

    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. 19 páginas, 18 figuras, 3 tablas.-- et al. Peer reviewed

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