Cosmic Microwave Background Radiation: PLANCK and LSPE

PLANCK - Low Frequency Instrument

Planck is a European Space Agency mission dedicated to the measurement of the Cosmic Microwave Background (CMB). The Planck satellite was launched from the Centre Spatial Guyanais (CGS) on May 14, 2009 and has been fully operational since the August of that year. The operations will end on October 23, 2013 but the scientific acquisition will stop on October 3, at the end of the eighth survey of the entire sky to allow a final round of calibration and verification of the performance of the instrument.

The purpose of the mission is to map the microwave sky with an unprecedented combination of frequency range, angular resolution, sensitivity, sky coverage, calibration accuracy, and freedom from systematic errors. Two consortiums are involved, each one responsible for an instrument and for performing the relative data processing. The low frequency instrument (LFI) is composed of an array of radiometers based on cryogenic HEMT amplifiers cooled to 20 K and working at three frequencies (30 - 70 GHz), whereas the high frequency instrument (HFI) is an array of bolometers working at six frequencies (100 - 850 GHz), cooled to 0.1 K. The main scientific goals are to produce all-sky maps of all the major sources of microwave to far-infrared emission, toprovide high-precision measurements of the anisotropies of the cosmic microwave background and to evaluate the main cosmological parameters.

During the period of satellite visibility (3h per day), spacecraft and instrument telemetry is dumped to the Ground Station, located in Perth, and sent to the ESA's Mission Operations Centre in Darmstadt to monitor the health of the overall system. Data are then made available to the instrument consortiums, retrieved by the first level of the Science Ground Segment, run by the Instrument Operation Team (IOT) and hosted at the instrument’s Data Processing Centre (DPC). The DPC  fo the LFI is located in Trieste at INAF-OATS.

The Planck-LFI IOT group in Trieste was closely involved in the final preparatory phases of the mission and once in flight, in the phase of LFI instrument optimization and calibration being in charge of operations and testing of the instrument (Instrument Operation Manager and Assembly-Integration-Verification AIV Manager). Now its main task at the LFI DPC is to guarantee the correct and healthy functioning of the instrument. This is achieved through continuous analysis of the telemetry, with the production of daily and weekly reports in which instrument performance and trend behavior is described, and whenever necessary, requesting changes in the instrumental setup.

 

LSPE - Large Scale Polarization Explorer

LSPE (Large Scale Polarization Explorer) is a project on a stratospheric balloon approved by ASI in 2010,  its launch is expected in 2014/2015 from the base of Longyearbyen on Svalbard. The role of the group of our department is configured as part of the instrument at low frequency STRIP (Stratospheric Italian Polarimeter) and in particular in the activities of the definition of the on-board software of which we have the responsibility for its realization, implementation and testing.

The STRIP (STRatospheric Italian Polarimeter) instrument is an array of coherent receivers designed to fly on board the LSPE balloon experiment. The STRIP focal plane array comprises 49 elements in Q-band and 7 elements in W-band. The LSPE experiment aims at large scale, high sensitivity measurements of CMB polarization, with multi-frequency deep measurements to optimize component separation. The STRIP Q-band channel is crucial to accurately measure and remove the synchrotron polarized component, while the W-band channel, together with a bolometric channel at the same frequency, provides a crucial cross-check for systematic effects.

Head of Research Group
Head: 
Anna Gregorio

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Last update: 10-15-2019 - 18:50