15 research outputs found
Planck pre-launch status: calibration of the Low Frequency Instrument flight model radiometers
The Low Frequency Instrument (LFI) on-board the ESA Planck satellite carries
eleven radiometer subsystems, called Radiometer Chain Assemblies (RCAs), each
composed of a pair of pseudo-correlation receivers. We describe the on-ground
calibration campaign performed to qualify the flight model RCAs and to measure
their pre-launch performances. Each RCA was calibrated in a dedicated
flight-like cryogenic environment with the radiometer front-end cooled to 20K
and the back-end at 300K, and with an external input load cooled to 4K. A
matched load simulating a blackbody at different temperatures was placed in
front of the sky horn to derive basic radiometer properties such as noise
temperature, gain, and noise performance, e.g. 1/f noise. The spectral response
of each detector was measured as was their susceptibility to thermal variation.
All eleven LFI RCAs were calibrated. Instrumental parameters measured in these
tests, such as noise temperature, bandwidth, radiometer isolation, and
linearity, provide essential inputs to the Planck-LFI data analysis.Comment: 15 pages, 18 figures. Accepted for publication in Astronomy and
Astrophysic
Planck pre-launch status: Low Frequency Instrument calibration and expected scientific performance
We give the calibration and scientific performance parameters of the Planck
Low Frequency Instrument (LFI) measured during the ground cryogenic test
campaign. These parameters characterise the instrument response and constitute
our best pre-launch knowledge of the LFI scientific performance. The LFI shows
excellent stability and rejection of instrumental systematic effects;
measured noise performance shows that LFI is the most sensitive instrument of
its kind. The set of measured calibration parameters will be updated during
flight operations through the end of the mission.Comment: Accepted for publications in Astronomy and Astrophysics. Astronomy &
Astrophysics, 2010 (acceptance date: 12 Jan 2010
Planck early results III : First assessment of the Low Frequency Instrument in-flight performance
Peer reviewe
Noise properties of the Planck-LFI receivers
The Planck Low Frequency Instrument (LFI) radiometers have been tested extensively during several dedicated campaigns. The present paper reports the principal noise properties of the LFI radiometers. A brief description of the LFI radiometers is given along with details of the test campaigns relevant to determination of noise properties. Current estimates of flight sensitivities, 1/f parameters, and noise effective bandwidths are presented. The LFI receivers exhibit exceptional 1/f noise, and their white noise performance is sufficient for the science goals of Planck. © 2009 IOP Publishing Ltd and SISSA
Methodological protocol for assessing the environmental footprint by means of ecotoxicological tools: wastewater treatment plants as an example case
The ecotoxicological tools reveal to be profitably employable within the assessment of the so-called environmental footprint, which is commonly based on the results of a chemical monitoring. Due to the heterogeneity of biological endpoints and the possibility to explore several exposure frames, as well as to consider higher levels of organization (from cells to organisms and mesocosms), the definition of a protocol is desirable
Calibration and testing of the Planck-LFI QM instrument
In this paper we present the test results of the qualification model (QM) of the LFI instrument, which is being developed as part of the ESA Planck satellite. In particular we discuss the calibration plan which has defined the main requirements of the radiometric tests and of the experimental setups. Then we describe how these requirements have been implemented in the custom-developed cryo-facilities and present the main results. We conclude with a discussion of the lessons learned for the testing of the LFI Flight Model (FM)