2008
Journal article
Open Access
Component separation methods for the PLANCK mission
Leach S. M., Cardoso J., Baccigalupi C., Barreiro R. B., Betoule M., Bobin J., Bonaldi A., Delabrouille J., De Zotti G., Dickinson C., Eriksen H. K., Gonzalez-Nuevo J., Hansen F. K., Herranz D., Le Jeune M., Lopez-Caniego M., Martinez-Gonzalez E., Massardi M., Melin J., Miville-Dechêne M., Patanchon G., Prunet S., Ricciardi S., Salerno E., Sanz J. L., Stark J., Stivoli F., Stolyarov V., Stompor R., Vielva P.
Context. The planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. The CMB intensity and polarization that are its prime targets are contaminated by foreground emission. Aims. The goal of this paper is to compare proposed methods for separating CMB from foregrounds based on their di?erent spectral and spatial characteristics, and to separate the foregrounds into "components" with di?erent physical origins (Galactic synchrotron, free-free and dust emissions; extra-galactic and far-IR point sources; Sunyaev-Zeldovich e?ect, etc.). Methods. A component separation challenge has been organised, based on a set of realistically complex simulations of sky emission. Several methods including those based on internal template subtraction, maximum entropy method, parametric method, spatial and harmonic cross correlation methods, and independent component analysis have been tested. Results. Di?erent methods proved to be e?ective in cleaning the CMB maps of foreground contamination, in reconstructing maps of di?use Galactic emissions, and in detecting point sources and thermal Sunyaev-Zeldovich signals. The power spectrum of the residuals is, on the largest scales, four orders of magnitude lower than the input Galaxy power spectrum at the foreground minimum. The CMB power spectrum was accurately recovered up to the sixth acoustic peak. The point source detection limit reaches 100 mJy, and about 2300 clusters are detected via the thermal SZ e?ect on two thirds of the sky.We have found that no single method performs best for all scientific objectives. Conclusions. We foresee that the final component separation pipeline for planck will involve a combination of methods and iterations between processing steps targeted at di?erent objectives such as di?use component separation, spectral estimation, and compact source extraction.Source: Astronomy & astrophysics (Print) 491 (2008): 597–615. doi:10.1051/0004-6361:200810116
DOI: 10.1051/0004-6361:200810116
DOI: 10.48550/arxiv.0805.0269
Metrics:
Leach S. M., Cardoso J., Baccigalupi C., Barreiro R. B., Betoule M., Bobin J., Bonaldi A., Delabrouille J., De Zotti G., Dickinson C., Eriksen H. K., Gonzalez-Nuevo J., Hansen F. K., Herranz D., Le Jeune M., Lopez-Caniego M., Martinez-Gonzalez E., Massardi M., Melin J., Miville-Dechêne M., Patanchon G., Prunet S., Ricciardi S., Salerno E., Sanz J. L., Stark J., Stivoli F., Stolyarov V., Stompor R., Vielva P.
Context. The planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. The CMB intensity and polarization that are its prime targets are contaminated by foreground emission. Aims. The goal of this paper is to compare proposed methods for separating CMB from foregrounds based on their di?erent spectral and spatial characteristics, and to separate the foregrounds into "components" with di?erent physical origins (Galactic synchrotron, free-free and dust emissions; extra-galactic and far-IR point sources; Sunyaev-Zeldovich e?ect, etc.). Methods. A component separation challenge has been organised, based on a set of realistically complex simulations of sky emission. Several methods including those based on internal template subtraction, maximum entropy method, parametric method, spatial and harmonic cross correlation methods, and independent component analysis have been tested. Results. Di?erent methods proved to be e?ective in cleaning the CMB maps of foreground contamination, in reconstructing maps of di?use Galactic emissions, and in detecting point sources and thermal Sunyaev-Zeldovich signals. The power spectrum of the residuals is, on the largest scales, four orders of magnitude lower than the input Galaxy power spectrum at the foreground minimum. The CMB power spectrum was accurately recovered up to the sixth acoustic peak. The point source detection limit reaches 100 mJy, and about 2300 clusters are detected via the thermal SZ e?ect on two thirds of the sky.We have found that no single method performs best for all scientific objectives. Conclusions. We foresee that the final component separation pipeline for planck will involve a combination of methods and iterations between processing steps targeted at di?erent objectives such as di?use component separation, spectral estimation, and compact source extraction.Source: Astronomy & astrophysics (Print) 491 (2008): 597–615. doi:10.1051/0004-6361:200810116
DOI: 10.1051/0004-6361:200810116
DOI: 10.48550/arxiv.0805.0269
Metrics:
See at:
arXiv.org e-Print Archive 
| SISSA Digital Library | Caltech Authors | Astronomy and Astrophysics | Astronomy and Astrophysics 
| doi.org | HAL-Inserm | www.aanda.org | CNR ExploRA
2009
Journal article
Restricted
Permittivity range profile reconstruction of multilayered structures from microwave backscattering data by using particle swarm optimization
Genovesi S., Salerno E., Monorchio A., Manara G.
A method for the investigation of multilayered structures by using microwave probes is proposed. An iterative optimization procedure reconstructs the permittivity range profiles of such structures from backscattering data by optimizing a functional with a data term and a regularization term, including a line process to overcome the global smoothness enforced by classical regularization.Source: Microwave and optical technology letters (Print) 51 (2009): 2390–2394. doi:10.1002/mop.24642
DOI: 10.1002/mop.24642
Metrics:
Genovesi S., Salerno E., Monorchio A., Manara G.
A method for the investigation of multilayered structures by using microwave probes is proposed. An iterative optimization procedure reconstructs the permittivity range profiles of such structures from backscattering data by optimizing a functional with a data term and a regularization term, including a line process to overcome the global smoothness enforced by classical regularization.Source: Microwave and optical technology letters (Print) 51 (2009): 2390–2394. doi:10.1002/mop.24642
DOI: 10.1002/mop.24642
Metrics:
See at:
Microwave and Optical Technology Letters | onlinelibrary.wiley.com | CNR ExploRA
2002
Journal article
Unknown
Come i computer hanno influenzato le discipline umanistiche
Salerno E.
An abstract is not availableSource: Jekyll. comm. 3 (2002).
Salerno E.
An abstract is not availableSource: Jekyll. comm. 3 (2002).
See at: CNR ExploRA
2003
Journal article
Unknown
Quando l'astrofisica chiede aiuto all'informatica. L'analisi dei dati astrofisici ha bisogno della ricerca informatica più avanzata
Salerno E.
L'elaborazione statistica dei segnali sia avvia ad assumere un ruolo chiave nello studio del nostro Universo. Molti problemi dell'astrofisica sono infatti legati alla possibilità di discriminare tra teorie in competizione nell'affascinante impresa di comprenderne la nascita, l'evoluzione e il destino, e un loro aspetto comune è che l'informazione utile si deve estrarre da insiemi di dati di dimensione enorme e affetti da notevoli errori. Dal punto di vista informatico si tratta di 'data mining', ossia di ricerca di informazione nascosta. Un caso in cui oggi si deve ricorrere a tecniche di data mining è rappresentato dallo studio della radiazione cosmica di fondo.Source: Ricerca e Futuro 21 (2003): 21–22.
Salerno E.
L'elaborazione statistica dei segnali sia avvia ad assumere un ruolo chiave nello studio del nostro Universo. Molti problemi dell'astrofisica sono infatti legati alla possibilità di discriminare tra teorie in competizione nell'affascinante impresa di comprenderne la nascita, l'evoluzione e il destino, e un loro aspetto comune è che l'informazione utile si deve estrarre da insiemi di dati di dimensione enorme e affetti da notevoli errori. Dal punto di vista informatico si tratta di 'data mining', ossia di ricerca di informazione nascosta. Un caso in cui oggi si deve ricorrere a tecniche di data mining è rappresentato dallo studio della radiazione cosmica di fondo.Source: Ricerca e Futuro 21 (2003): 21–22.
See at: CNR ExploRA
2007
Journal article
Open Access
CLeMUS - Computational Learning Methods for Unsupervised Segmentation
Salerno E., Wilson S.
An invited session on computational learning methods for unsupervised segmentation was held on 14 September in the framework of the 11th International Conference on Knowledge-Based and Intelligent Information & Engineering Systems (KES 2007) in Vietri sul Mare, Italy. This initiative was taken by the MUSCLE 'e-team' on unsupervised segmentation and classification of multichannel data. MUSCLE (Multimedia Understanding through Semantics, Computation and Learning) is a European network of excellence managed by ERCIM.Source: ERCIM news 71 (2007).
Salerno E., Wilson S.
An invited session on computational learning methods for unsupervised segmentation was held on 14 September in the framework of the 11th International Conference on Knowledge-Based and Intelligent Information & Engineering Systems (KES 2007) in Vietri sul Mare, Italy. This initiative was taken by the MUSCLE 'e-team' on unsupervised segmentation and classification of multichannel data. MUSCLE (Multimedia Understanding through Semantics, Computation and Learning) is a European network of excellence managed by ERCIM.Source: ERCIM news 71 (2007).
See at:
ercim-news.ercim.org | CNR ExploRA
2010
Journal article
Open Access
Scientific computing for astrophysical map analysis
Salerno E.
A research team at the Signal and Image Processing Lab of ISTI-CNR has been involved in studying data analysis algorithms for the European Space Agency's Planck Surveyor Satellite since 1999. The huge amount of data on the cosmic microwave background radiation provided by the Planck sensors requires very efficient analysis algorithms and high-performance computing facilities. The CNR group has proposed some of the source separation procedures that are now operational at the Planck data processing centre in Trieste, Italy.Source: ERCIM news 81 (2010): 20–21.
Salerno E.
A research team at the Signal and Image Processing Lab of ISTI-CNR has been involved in studying data analysis algorithms for the European Space Agency's Planck Surveyor Satellite since 1999. The huge amount of data on the cosmic microwave background radiation provided by the Planck sensors requires very efficient analysis algorithms and high-performance computing facilities. The CNR group has proposed some of the source separation procedures that are now operational at the Planck data processing centre in Trieste, Italy.Source: ERCIM news 81 (2010): 20–21.
See at:
ercim-news.ercim.eu | CNR ExploRA
2005
Conference article
Unknown
A permittivity range profile reconstruction technique for multilayered structures by a line process-augmented genetic algorithm
Genovesi S., Salerno E., Monorchio A., Manara G.
This paper presents a technique to reconstruct the permittivity range profile of a layered medium using noisy backscattering data. Being an ill-posed problem, inverse scattering normally provides either unstable or oversmoothed results. Our method tries to obtain an accurate reconstruction using a two-step genetic algorithm employing a regularization constraint with an explicit line process and a local deterministic optimization strategy.Source: 2005 IEEE AP-S International Symposium and USNC/URSI National Radio Science, Washington DC, USA, 3-8 July 2005
Genovesi S., Salerno E., Monorchio A., Manara G.
This paper presents a technique to reconstruct the permittivity range profile of a layered medium using noisy backscattering data. Being an ill-posed problem, inverse scattering normally provides either unstable or oversmoothed results. Our method tries to obtain an accurate reconstruction using a two-step genetic algorithm employing a regularization constraint with an explicit line process and a local deterministic optimization strategy.Source: 2005 IEEE AP-S International Symposium and USNC/URSI National Radio Science, Washington DC, USA, 3-8 July 2005
See at: CNR ExploRA
2006
Conference article
Unknown
Dependent component analysis as a tool for blind spectral unmixing of remote sensed images
Caiafa C. F., Salerno E., Proto A. N., Fiumi L.
In this work, we present a blind technique for the estimation of the material abundances per pixel (end-members) in hyperspectral remote-sensed images. Classical spectral unmixing techniques require the knowledge of the existing materials and their spectra. This is a problem when no prior information is available. Some techniques based on independent component analysis proved not to be very efficient for the strong dependence among the material abundances always found in real data. We approach the problem of blind separation of end members by applying the MaxNG algorithm, which is capable to separate even sensibly dependent signals. We also present a minimum-mean-squared-error method to estimate the unknown scale factors by exploiting the source constraint. The results shown here have been obtained from either synthetic or real data. The synthetic images have been generated by a noisy linear mixture model with real, spatially variable, endmember spectra. The real images have been captured by the MIVIS airborne imaging spectrometer. Our results showed that MaxNG is able to separate the endmembers successfully if a linear mixing model holds true and for low noise and reduced spectral variability conditions.Source: European Signal Processing Conference - EUSIPCO 2006, Florence, Italy, 04-08/09/2006
Caiafa C. F., Salerno E., Proto A. N., Fiumi L.
In this work, we present a blind technique for the estimation of the material abundances per pixel (end-members) in hyperspectral remote-sensed images. Classical spectral unmixing techniques require the knowledge of the existing materials and their spectra. This is a problem when no prior information is available. Some techniques based on independent component analysis proved not to be very efficient for the strong dependence among the material abundances always found in real data. We approach the problem of blind separation of end members by applying the MaxNG algorithm, which is capable to separate even sensibly dependent signals. We also present a minimum-mean-squared-error method to estimate the unknown scale factors by exploiting the source constraint. The results shown here have been obtained from either synthetic or real data. The synthetic images have been generated by a noisy linear mixture model with real, spatially variable, endmember spectra. The real images have been captured by the MIVIS airborne imaging spectrometer. Our results showed that MaxNG is able to separate the endmembers successfully if a linear mixing model holds true and for low noise and reduced spectral variability conditions.Source: European Signal Processing Conference - EUSIPCO 2006, Florence, Italy, 04-08/09/2006
See at: CNR ExploRA
2010
Contribution to book
Unknown
'Blind' does not mean visually challenged: extracting source signals from mixed data
Salerno E.
This paper introduces the problem of blind source separation, a phrase that denotes a class of techniques aimed at estimating signals when the physical system through which they are sensed is not known. The solution to this problem thus entails both system identification and signal estimation. Actually, I show that any lack of information on the physical system must be replaced by information on signals, and that, although a reliable data model is lacking, many pieces of information are used to constrain it. I only introduce some basic principles, with just a few details on the techniques used in practice, but the bibliography can help the reader to deepen their understanding of the matter. Most of the material is introduced by examples.Source: Selected Papers from DSP Application Day 2009, edited by MALCANGI Mario, pp. 77–89. Milano: CLUP, 2010
Salerno E.
This paper introduces the problem of blind source separation, a phrase that denotes a class of techniques aimed at estimating signals when the physical system through which they are sensed is not known. The solution to this problem thus entails both system identification and signal estimation. Actually, I show that any lack of information on the physical system must be replaced by information on signals, and that, although a reliable data model is lacking, many pieces of information are used to constrain it. I only introduce some basic principles, with just a few details on the techniques used in practice, but the bibliography can help the reader to deepen their understanding of the matter. Most of the material is introduced by examples.Source: Selected Papers from DSP Application Day 2009, edited by MALCANGI Mario, pp. 77–89. Milano: CLUP, 2010
See at: CNR ExploRA
2003
Other
Open Access
IFATEST v.0.0: manuale del programmatore
Salerno E.
IFATEST è un codice in Fortran 90 per la sperimentazione di un algoritmo di analisi ai fattori indipendenti (IFA) ispirato a quello presentato da Attias in [1]. Lo scopo di questo algoritmo è quello della separazione cieca di segnali ottenuti da misture istantanee rumorose di sorgenti indipendenti. La variante qui proposta [2] prevede l'uso di una strategia di annealing simulato piuttosto che l'algoritmo Expectation-Maximization proposto da Attias per l'apprendimento del modello dati. I potenziali vantaggi di questa strategia consistono nell'indipendenza della soluzione dalla stima iniziale e in una maggiore robustezza nei confronti del rumore. I primi risultati ottenuti [2] vanno verso una conferma di queste aspettative. Un altro sicuro vantaggio dell'annealing simulato sull'approccio di Attias è che le eventuali informazioni a priori su alcuni dei parametri incogniti del problema possono essere inserite facilmente nella strategia di ottimizzazione. In questa prima stesura del codice non è sfruttata la possibilità di trattare rumore non stazionario, che, in base ad opportune approssimazioni, può essere un vantaggio dell'approccio IFA sugli algoritmi proposti in precedenza per la separazione cieca di sorgenti [2, 3]. Il codice qui presentato non ha limitazioni sul numero massimo di sorgenti e canali di misura da trattare (salvo, ovviamente, limitazioni di memoria e di tempo di elaborazione) e consente di variare con estrema facilità i parametri del modello che devono venire considerati incogniti, i valori dei parametri da considerare noti e la stima iniziale della soluzione. Anche lo schema di annealing può essere facilmente modificato.
Salerno E.
IFATEST è un codice in Fortran 90 per la sperimentazione di un algoritmo di analisi ai fattori indipendenti (IFA) ispirato a quello presentato da Attias in [1]. Lo scopo di questo algoritmo è quello della separazione cieca di segnali ottenuti da misture istantanee rumorose di sorgenti indipendenti. La variante qui proposta [2] prevede l'uso di una strategia di annealing simulato piuttosto che l'algoritmo Expectation-Maximization proposto da Attias per l'apprendimento del modello dati. I potenziali vantaggi di questa strategia consistono nell'indipendenza della soluzione dalla stima iniziale e in una maggiore robustezza nei confronti del rumore. I primi risultati ottenuti [2] vanno verso una conferma di queste aspettative. Un altro sicuro vantaggio dell'annealing simulato sull'approccio di Attias è che le eventuali informazioni a priori su alcuni dei parametri incogniti del problema possono essere inserite facilmente nella strategia di ottimizzazione. In questa prima stesura del codice non è sfruttata la possibilità di trattare rumore non stazionario, che, in base ad opportune approssimazioni, può essere un vantaggio dell'approccio IFA sugli algoritmi proposti in precedenza per la separazione cieca di sorgenti [2, 3]. Il codice qui presentato non ha limitazioni sul numero massimo di sorgenti e canali di misura da trattare (salvo, ovviamente, limitazioni di memoria e di tempo di elaborazione) e consente di variare con estrema facilità i parametri del modello che devono venire considerati incogniti, i valori dei parametri da considerare noti e la stima iniziale della soluzione. Anche lo schema di annealing può essere facilmente modificato.
See at:
ISTI Repository | CNR ExploRA
2003
Other
Open Access
Un sistema per misure multistatiche di campo elettromagnetico diffuso
Salerno E.
In questa nota si descrive un progetto preliminare per un sistema di misura dedicato all'ispezione non distruttiva di manufatti in calcestruzzo, di interesse per il progetto coordinato 'Un sensore portatile per la diagnostica elettromagnetica non invasiva dello stato interno di strutture monumentali', finanziato con attribuzione straordinaria da Agenzia 2000 - CNR. Rispetto a quanto previsto nel primo studio di fattibilità, il sistema qui descritto contiene modifiche parziali derivate da affinamenti nelle specifiche di progetto. Il nuovo sistema richiede un dispositivo supplementare di posizionamento e l'uso di uno switch DPDT comandabile da calcolatore. Il costo stimato per queste modifiche è risultato abbastanza contenuto.
Salerno E.
In questa nota si descrive un progetto preliminare per un sistema di misura dedicato all'ispezione non distruttiva di manufatti in calcestruzzo, di interesse per il progetto coordinato 'Un sensore portatile per la diagnostica elettromagnetica non invasiva dello stato interno di strutture monumentali', finanziato con attribuzione straordinaria da Agenzia 2000 - CNR. Rispetto a quanto previsto nel primo studio di fattibilità, il sistema qui descritto contiene modifiche parziali derivate da affinamenti nelle specifiche di progetto. Il nuovo sistema richiede un dispositivo supplementare di posizionamento e l'uso di uno switch DPDT comandabile da calcolatore. Il costo stimato per queste modifiche è risultato abbastanza contenuto.
See at:
ISTI Repository | CNR ExploRA
2005
Report
Open Access
Using a nonlinear Landweber algorithm to reconstruct 1D permittivity range profiles from coherent microwave backscattering data
Salerno E.
This report deals with an application of the Landweber iteration to solve a one-dimensional inverse problem of interest in nondestructive evaluation. This algorithm is based on a nonlinear data model, and is particularized on a specific discretization of the equation of electromagnetic scalar scattering from lossless dielectric materials.Source: ISTI Technical reports, 2005
Salerno E.
This report deals with an application of the Landweber iteration to solve a one-dimensional inverse problem of interest in nondestructive evaluation. This algorithm is based on a nonlinear data model, and is particularized on a specific discretization of the equation of electromagnetic scalar scattering from lossless dielectric materials.Source: ISTI Technical reports, 2005
See at:
ISTI Repository | CNR ExploRA
2006
Report
Open Access
Scale disambiguation of blindly unmixed endmember abundances
Salerno E.
The problem of estimating the scale factors related to blindly separated relative abundance maps is addressed. The nature of the quantities looked for is such that their sum must be everywhere equal to one. Exploiting this property, the problem is solved within the framework of a linear noisy mixture model, with signal-independent and zero-mean noise.Source: ISTI Technical reports, 2006
Salerno E.
The problem of estimating the scale factors related to blindly separated relative abundance maps is addressed. The nature of the quantities looked for is such that their sum must be everywhere equal to one. Exploiting this property, the problem is solved within the framework of a linear noisy mixture model, with signal-independent and zero-mean noise.Source: ISTI Technical reports, 2006
See at:
ISTI Repository | CNR ExploRA
2006
Report
Open Access
A noisy data model for MaxNG
Salerno E.
A noise-insensitive Euclidean distance function is derived for the MaxNG algorithm. This is a dependent-component-analysis source-separation algorithm based on the maximization of a nongaussianity measure, and has recently been developed for a noiseless mixture model. It is shown that, in the case of observations corrupted by signal-independent stationary Gaussian noise, the probability density function of the output process can be easily made independent of noise if it is approximated via the Parzen-windows method with Gaussian kernels. The role assumed by the aperture parameter is shown to be similar to the one of the regularization parameter in any inverse problem.Source: ISTI Technical reports, 2006
Salerno E.
A noise-insensitive Euclidean distance function is derived for the MaxNG algorithm. This is a dependent-component-analysis source-separation algorithm based on the maximization of a nongaussianity measure, and has recently been developed for a noiseless mixture model. It is shown that, in the case of observations corrupted by signal-independent stationary Gaussian noise, the probability density function of the output process can be easily made independent of noise if it is approximated via the Parzen-windows method with Gaussian kernels. The role assumed by the aperture parameter is shown to be similar to the one of the regularization parameter in any inverse problem.Source: ISTI Technical reports, 2006
See at:
ISTI Repository | CNR ExploRA
2001
Report
Unknown
Guest editorial: fast energy-minimization-based imaging and vision techniques
Salerno E.
Image processing and computer visionSource: ISTI Technical reports, 2001
Salerno E.
Image processing and computer visionSource: ISTI Technical reports, 2001
See at: CNR ExploRA
2004
Report
Open Access
Edge-Preserving Permittivity Range Profile Reconstruction by a Genetic Algorithm
Salerno E., Genovesi S., Monorchio A., Manara G.
Reconstructing the permittivity range profile of a layered medium from bandlimited backscattered data always implies either higly unstable or oversmoothed results. To avoid this drawback, we introduce an edge-preserving regularization constraint with explicitly marked lines. The inverse scattering problem is solved by a genetic optimization algorithm.Source: ISTI Technical reports, pp.1–7, 2004
Salerno E., Genovesi S., Monorchio A., Manara G.
Reconstructing the permittivity range profile of a layered medium from bandlimited backscattered data always implies either higly unstable or oversmoothed results. To avoid this drawback, we introduce an edge-preserving regularization constraint with explicitly marked lines. The inverse scattering problem is solved by a genetic optimization algorithm.Source: ISTI Technical reports, pp.1–7, 2004
See at:
ISTI Repository | CNR ExploRA
2008
Other
Open Access
Appunti di microonde
Salerno E.
Lecture notes from the courses in Microwaves at the undergraduate school of Telecommunication Engineering, University of Pisa. Academic Years 2003-04/2006-07.
Salerno E.
Lecture notes from the courses in Microwaves at the undergraduate school of Telecommunication Engineering, University of Pisa. Academic Years 2003-04/2006-07.
See at:
ISTI Repository | CNR ExploRA
2008
Report
Open Access
Component separation methods for the Planck mission
Leach S. M., Cardoso J. -F., Baccigalupi C., Barreiro R. B., Betoule M., Bobin J., Bonaldi A., De Zotti G., Delabrouille J., Dickinson C., Eriksen H. K., Gonzalez-Nuevo J., Hansen F. K., Herranz D., Le Jeune M., Lopez-Caniego M., Martinez-Gonzalez E., Massardi M., Melin J. -B., Miville-Deschenes M. -A., Patanchon G., Prunet S., Ricciardi S., Salerno E., Sanz J. L., Starck J. -L., Stivoli F., Stolyarov V., Stompor R., Vielva P.
Context. The Planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. The CMB intensity and polarization that are its prime targets are contaminated by foreground emission. Aims. The goal of this paper is to compare proposed methods for separating CMB from foregrounds based on their different spectral and spatial characteristics, and to separate the foregrounds into 'components' of different physical origin (Galactic synchrotron, freefree and dust emissions; extra-galactic and far-IR point sources; Sunyaev-Zeldovich effect, etc). Methods. A component separation challenge has been organized, based on a set of realistically complex simulations of sky emission. Several methods including those based on internal template subtraction, maximum entropy method, parametric method, spatial and harmonic cross correlation methods, and independent component analysis have been tested. Results. Different methods proved to be effective in cleaning the CMB maps from foreground contamination, in reconstructing maps of diff use Galactic emissions, and in detecting point sources and thermal Sunyaev-Zeldovich signals. The power spectrum of the residuals is, on the largest scales, four orders of magnitude lower than that of the input Galaxy power spectrum at the foreground minimum. The CMB power spectrum was accurately recovered up to the sixth acoustic peak. The point source detection limit reaches 100 mJy, and about 2300 clusters are detected via the thermal SZ effect on two thirds of the sky. We have found that no single method performs best for all scientific objectives. Conclusions. We foresee that the final component separation pipeline for Planck will involve a combination of methods and iterations between processing steps targeted at different objectives such as diff use component separation, spectral estimation and compact source extraction.Source: ISTI Technical reports, 2008
Leach S. M., Cardoso J. -F., Baccigalupi C., Barreiro R. B., Betoule M., Bobin J., Bonaldi A., De Zotti G., Delabrouille J., Dickinson C., Eriksen H. K., Gonzalez-Nuevo J., Hansen F. K., Herranz D., Le Jeune M., Lopez-Caniego M., Martinez-Gonzalez E., Massardi M., Melin J. -B., Miville-Deschenes M. -A., Patanchon G., Prunet S., Ricciardi S., Salerno E., Sanz J. L., Starck J. -L., Stivoli F., Stolyarov V., Stompor R., Vielva P.
Context. The Planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. The CMB intensity and polarization that are its prime targets are contaminated by foreground emission. Aims. The goal of this paper is to compare proposed methods for separating CMB from foregrounds based on their different spectral and spatial characteristics, and to separate the foregrounds into 'components' of different physical origin (Galactic synchrotron, freefree and dust emissions; extra-galactic and far-IR point sources; Sunyaev-Zeldovich effect, etc). Methods. A component separation challenge has been organized, based on a set of realistically complex simulations of sky emission. Several methods including those based on internal template subtraction, maximum entropy method, parametric method, spatial and harmonic cross correlation methods, and independent component analysis have been tested. Results. Different methods proved to be effective in cleaning the CMB maps from foreground contamination, in reconstructing maps of diff use Galactic emissions, and in detecting point sources and thermal Sunyaev-Zeldovich signals. The power spectrum of the residuals is, on the largest scales, four orders of magnitude lower than that of the input Galaxy power spectrum at the foreground minimum. The CMB power spectrum was accurately recovered up to the sixth acoustic peak. The point source detection limit reaches 100 mJy, and about 2300 clusters are detected via the thermal SZ effect on two thirds of the sky. We have found that no single method performs best for all scientific objectives. Conclusions. We foresee that the final component separation pipeline for Planck will involve a combination of methods and iterations between processing steps targeted at different objectives such as diff use component separation, spectral estimation and compact source extraction.Source: ISTI Technical reports, 2008
See at:
ISTI Repository | CNR ExploRA
2008
Report
Unknown
MUSCLE - E-team 13 Final Activity Report
Salerno E.
This report describes the common activities performed within the MUSCLE e-team on unsupervised segmentation and classification of multichannel data. Active under MUSCLE JPA3 and JPA4, this e-team has been first named e-team 15 and then (after June 2007) e-team 13. The work plan included the implementation of tools for remote collaboration, integration of research on statistical approaches to soft segmentation, and organization of both internal and open meetings to foster collaboration and disseminate our work. The strict collaboration on Bayesian separation techniques has produced a paper, ready to be submitted for publication, on a promising MCMC technique to separate astrophysical source maps, which is being assessed with the help of astrophysicists. Further work on document image processing and remote sensing has also produced results documented in the literature. The e-team organized an invited session on computational learning for unsupervised segmentation at the international conference KES 2007.Source: Project report, MUSCLE, Deliverable DN6.1, 2008
Salerno E.
This report describes the common activities performed within the MUSCLE e-team on unsupervised segmentation and classification of multichannel data. Active under MUSCLE JPA3 and JPA4, this e-team has been first named e-team 15 and then (after June 2007) e-team 13. The work plan included the implementation of tools for remote collaboration, integration of research on statistical approaches to soft segmentation, and organization of both internal and open meetings to foster collaboration and disseminate our work. The strict collaboration on Bayesian separation techniques has produced a paper, ready to be submitted for publication, on a promising MCMC technique to separate astrophysical source maps, which is being assessed with the help of astrophysicists. Further work on document image processing and remote sensing has also produced results documented in the literature. The e-team organized an invited session on computational learning for unsupervised segmentation at the international conference KES 2007.Source: Project report, MUSCLE, Deliverable DN6.1, 2008
See at: CNR ExploRA
2009
Report
Open Access
Misure non invasive a microonde ed ultrasuoni su materiali lapidei
Algozino L.
During a stage at ISTI's Signals and Images Laboratory, I performed a number of nondestructive near-field microwave tests on lapideous materials relevant to cultural and architectural heritage (different marble samples), to detect and identify possible internal anomalies. The final goal is to experiment resonant microwave sensors developed at ISTI and to validate pre-existing measurements on the same samples, also comparing the results with the typical permittivity values found in the literature. The technique considered uses a narrowband patch antenna whose resonant frequency depends on the material illuminated. By inverting the formula for the resonant frequency, the permittivity of the material under test, averaged over the illuminated volume, can be estimated, thus allowing a map of this quantity to be reconstructed as a function of the sensor position. The results obtained are presented and discussed. Complementary measurements based on ultrasound transmission were not performed because of a delay in a previously scheduled field measurement campaign.Source: ISTI Technical reports, 2009
Algozino L.
During a stage at ISTI's Signals and Images Laboratory, I performed a number of nondestructive near-field microwave tests on lapideous materials relevant to cultural and architectural heritage (different marble samples), to detect and identify possible internal anomalies. The final goal is to experiment resonant microwave sensors developed at ISTI and to validate pre-existing measurements on the same samples, also comparing the results with the typical permittivity values found in the literature. The technique considered uses a narrowband patch antenna whose resonant frequency depends on the material illuminated. By inverting the formula for the resonant frequency, the permittivity of the material under test, averaged over the illuminated volume, can be estimated, thus allowing a map of this quantity to be reconstructed as a function of the sensor position. The results obtained are presented and discussed. Complementary measurements based on ultrasound transmission were not performed because of a delay in a previously scheduled field measurement campaign.Source: ISTI Technical reports, 2009
See at:
ISTI Repository | CNR ExploRA