Bedini L., Herranz D., Salerno E., Baccigalupi C., Kuruoglu E. E., Tonazzini A.
This paper proposes a new strategy to separate astrophysical sources that are mutually correlated. This strategy is based on second order statistics and exploits prior information about the possible structure of the mixing matrix. Unlike ICA blind separation approaches, where the sources are assumed mutually independent and no prior knowledge is assumed about the mixing matrix, our strategy allows the independence assumption to be relaxed and performs the separation of even significantly correlated sources. Besides the mixing matrix, our strategy is also capable to evaluate the source covariance functions at several lags. Moreover, once the mixing parameters have been identified, a simple deconvolution can be used to estimate the probability density functions of the source processes. To benchmark our algorithm, we used a database that simulates the one expected from the instruments that will operate onboard ESA's Planck Surveyor Satellite to measure the CMB anisotropies all over the celestial sphere.
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L. Bedini graduated cum laude in electronic engineering from the University of Pisa, Italy, in 1968. Since 1970, he has been a researcher of the Italian National Research Council, Istituto di Scienza e Tecnologie dell'Informazione, Pisa, Italy. His interests have been in modelling, identification, and parameter estimation of biological systems applied to noninvasive diagnostic techniques. At present, his research interest is in the field of digital signal processing, image reconstruction, and neural networks applied to image processing. He is a coauthor of more than 80 scientific papers. From 1971 to 1989, he was an Associate Professor of system theory at the Computer Science Department, University of Pisa, Italy.
D. Herranz received the B.S. degree in 1995 and the M.S. degree in 1995 from the Universidad Complutense de Madrid, Madrid, Spain, and the Ph.D. degree in astrophysics from Universidad de Cantabria, Santander, Spain, in 2002. He was a CMBNET Postdoctoral Fellow at the Istituto di Scienza e Tecnologie dell'Informazione “A. Faedo” (CNR), Pisa, Italy, from 2002 to 2004. He is currently at the Instituto de Fisica de Cantabria, Santander, Spain, under an MEC Juan de la Cierva contract. His research interests are in the areas of cosmic microwave background astronomy and extragalactic point source statistics as well as the application of statistical signal processing to astronomical data, including blind source separation, linear and nonlinear data filtering, and statistical modeling of heavy-tailed processes.