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impaginato corretto fullone_Layout 1 13/10/15 12.09 Pagina 57 Department of Engineering, ICT and Technologies for Energy and Transport Patent Title Title Method for filtering interferometric data acquired Method for filtering interferometric data acquired by synthetic aperture radar (SAR). by synthetic aperture radar (SAR). Ref. CNR 10285 Ref. CNR 10285 Assignee(s): CNR CNR Institute: IREA Main Inventor: Gianfranco Fornaro Countries: IT, PCT Priority date: 19/07/2013 Abstract Abstract The present invention refers to a technique - named CAESAR (Component Extraction and Selection SAR) The present invention refers to a technique named CAESAR (Component Extraction and Selection SAR) - for filtering multipass interferometric data acquired by synthetic aperture radar (SAR). This technique for filtering multipass interferometric data acquired by synthetic aperture radar (SAR). This technique allows the extraction of the principal components of the data operating, on one hand, a data filtering allows the extraction of the principal components of the data operating, on one hand, a data filtering aimed to limit the effects of temporal and angular variations of the target response and, on the other aimed to limit the effects of temporal and angular variations of the target response and, on the other hand, a selection of interfering components associated with different structures on ground. In particular hand, a selection of interfering components associated with different structures on ground. In particular this interference effect has a dramatic impact in the analysis of urban areas. The innovation of CAESAR this interference effect has a dramatic impact in the analysis of urban areas. The innovation of CAESAR consists of allowing such an extraction and selection even in a preliminary stage of the data processing, consists of allowing such an extraction and selection even in a preliminary stage of the data processing, thus significantly improving the performances of the method used for interferometric SAR data analysis. thus significantly improving the performances of the method used for interferometric SAR data analysis. Background Background Multipass Differential SAR interferometry (DInSAR) is a cost effective technique for deformation monitoring Multipass Differential SAR interferometry (DInSAR) is a cost effective technique for deformation monitoring from satellite. SAR tomography is an evolution of this technique which enables an advanced monitoring at from satellite. SAR tomography is an evolution of this technique which enables an advanced monitoring at the scale of single buildings. It is also able to solve the problem of interference of different backscattering the scale of single buildings. It is also able to solve the problem of interference of different backscattering contributions. SAR tomography assumes that the data are calibrated through the products generated by contributions. SAR tomography assumes that the data are calibrated through the products generated by the low-resolution processing based on classical SAR interferometry techniques. the low resolution processing based on classical SAR interferometry techniques. Technology Technology CAESAR exploits the method of principal components analysis which is based on the estimation of the CAESAR exploits the method of principal components analysis which is based on the estimation of the covariance matrix associated with multipass SAR data. By taking advantage of this statistical analysis covariance matrix associated with multipass SAR data. By taking advantage of this statistical analysis method, CAESAR allows one to operate a filtering of the whole SAR dataset and to carry out an effective method, CAESAR allows one to operate a filtering of the whole SAR dataset and to carry out an effective separation of the components associated with different ground backscattering mechanisms interfering separation of the components associated with different ground backscattering mechanisms interfering within the same SAR image pixel, prior to the data calibration . within the same SAR image pixel, prior to the data calibration . Advantages and Applicatons Advantages and Applications Within the DInSAR analysis context, CAESAR is capable to filter and separate possible interfering Within the DInSAR analysis context, CAESAR is capable to filter and separate possible interfering contributions at an early processing stage, to improve the monitoring products in areas prone to natural contributions at an early processing stage, to improve the monitoring products in areas prone to natural hazards. On the other hand, with reference to the analysis at the scale of buildings and infrastructure, with hazards. On the other hand, with reference to the analysis at the scale of buildings and infrastructure, with respect to SAR tomography, CAESAR has shown its potentiality in significantly increasing the measurements respect to SAR tomography, CAESAR has shown its potentiality in significantly increasing the measurements density and / or reducing the dataset size. density and / or reducing the dataset size. Development stage Development stage A software prototype developed in Interactive Data Language (IDL) has been implemented. The method A software prototype developed in Interactive Data Language (IDL) has been implemented. The method has been validated on different datasets acquired by the SAR sensors of the COSMO/SKYMED has been validated on different datasets acquired by the SAR sensors of the COSMO/SKYMED 57 constellation. Recently, the effectiveness of CAESAR has been also verified within the framework of the constellation. Recently, the effectiveness of CAESAR has been also verified within the framework of the processing aimed at monitoring at the scale of single buildings and infrastructures. processing aimed at monitoring at the scale of single buildings and infrastructures.