| 摘要 |
The present invention concerns a Method for filtering interferometric data acquired by Synthetic Aperture Radar (SAR), comprising the following steps: (A) acquiring a plurality of images N by means of at least one sensor (A1,..., AM), which runs a plurality of orbits On, with n=1,..., N, in which the sensor (A1,..., AM) carries out a plurality of detections of at least one area t n , each detection during each orbit On being carried out in time references t n , with &eegr;=1...., N, emitting a radiation having a predetermined wavelength λ; so as to obtain a multipass data set comprising a set of N images of said at least one area, each of said images being composed of a plurality of pixels P in which targets may be present even possibly interfering due to effects of geometric distortions in the presence of structures with vertical development, said images being geometrically recorded compared to a reference image, to which a reference orbit is associated; (B) determining, for each pixel P of each of said N images, a signal column vector x(P) of length N, constituted by xn(P) signals, n = 1..., N detected by said sensor (A1,,..., AM) in each of said orbits On; (C) determining, for each pixel P of each of said images of said set of N images, a covariance matrix associated with said signal vector /(P); (D) determining the components of backscattering contributions of said signal vector x(P) by decomposing said covariance matrix, each backscattering contribution ŷ&kgr; having a value of the square of its norm λ&kgr;, with k =1,....,&kgr; < N, and said decomposition being obtained by at least one independent components separation method, such as a method based on the identification of orthogonal components (PCA) and/or a method based on the identification of scattered components, said backscattering contributions ŷ&kgr; being obtained from the decomposition into eigenvectors and eigenvalues of said covariance matrix by using the following relations:(see formula 1), in which the square of the norm Ak is the k-th ordered eigenvalue and uk is the corresponding eigenvector; and (E) arranging said backscattering contributions ŷ&kgr; in descending order according to said square of the norm λ and selecting a number K of said significant backscattering contributions ŷ&kgr;, according to the higher norm with respect to at least one threshold, as a threshold set with respect to the norm λ of the main backscattering contribution ŷ,. The present invention also concern a synthetic aperture radar remote sensing system. |
