New polarimetric signal subspace detectors for SAR processors

Abstract

Our studies aim at detecting targets embedded in a complex environment for radar applications. This article deals with new polarimetric SAR (synthetic aperture radar) processors based on subspace detectors. These algorithms use models of targets including physical and polarimetric properties of their scattering on the contrary to the isotropic point model that is commonly used. These processors are implemented by computing the corresponding subspaces that contain the relevant responses of the target. We choose for application the detection of targets under forest foliage. The obtained results both on simulated data of realistic targets and real data show the interest of these new processors.

New SAR target imaging algorithm based on oblique projection for clutter reduction

“…We propose to use the polarimetric information of the MMT and the deterministic interferences. Compared to classical SAR processors, we already showed for the SSDSAR a 8dB detection gain when considering two polarization channels (HH and VV in [18]). Therefore in this paper, the OBSAR algorithm (for Oblique SAR) is developed by incorporating the polarimetric information in the target and the interference subspaces.…”

“…Thus all the deterministic scatterers are modeled using the white and isotropic point [19]. Without considering random noise, the SAR received signals z p ∈ C N K×1 for single polarization p and z ∈ C 2N K×1 for dual polarization, of any deterministic scatterer at the position (x, y) can then be written as: 2) Polarimetric modeling: As proposed in [18], polarimetric SAR models r xy ∈ C 2N K×1 including contributions of H and V channels can be generated. To include polarimetric properties to r xy , we write it as follows:…”

“…Therefore, the SAR response of an interference located at the position (x, y) can be expressed as: We explain briefly in this section how to generate the target and interference subspaces and to compute the corresponding basis. For more details on the target subspace, see [7] for single polarization and [18] for dual polarization. The generation of the interference subspace in single polarization is presented in [8] and the corresponding generation in dual polarization is given in this paper.…”

“…• Polarimetric target subspaces: the generation of the polarimetric subspace has previously been studied in [18]. As a plate in free space describes only one polarimetric mechanism (trihedral type), we can apply the same method used for the white and isotropic point model, to characterize the polarimetric properties of the target.…”

“…For the polarimetric target subspace, the method presented in [18] is used. The polarimetric interference subspace generation is given in this paper.…”