Observation of the fine structures (anisotropies, polarization, spectral distortions) of the Cosmic Microwave Background (CMB) is hampered by instabilities, 1/f noise and asymmetries of the radiometers used to carry on the measurements. Addition of modulation and synchronous detection allows to increase the overall stability and the noise rejection of the radiometers used for CMB studies. In this paper we discuss the advantages this technique has when we try to detect CMB polarization. The behaviour of a two channel correlation receiver to which phase modulation and synchronous detection have been added is examined. Practical formulae for evaluating the improvements are presented.
CMB observations: improvements of the performance of correlation radiometers by signal modulation and synchronous detection / Spiga, D; Battistelli, Elia Stefano; Boella, G; Gervasi, M; Zannoni, M; Sironi, G.. - In: NEW ASTRONOMY. - ISSN 1384-1076. - 7:(2002), pp. 125-134. [10.1016/S1384-1076(02)00099-4]
CMB observations: improvements of the performance of correlation radiometers by signal modulation and synchronous detection
BATTISTELLI, Elia Stefano;
2002
Abstract
Observation of the fine structures (anisotropies, polarization, spectral distortions) of the Cosmic Microwave Background (CMB) is hampered by instabilities, 1/f noise and asymmetries of the radiometers used to carry on the measurements. Addition of modulation and synchronous detection allows to increase the overall stability and the noise rejection of the radiometers used for CMB studies. In this paper we discuss the advantages this technique has when we try to detect CMB polarization. The behaviour of a two channel correlation receiver to which phase modulation and synchronous detection have been added is examined. Practical formulae for evaluating the improvements are presented.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
