Interferometric Methods for 3-D Target Reconstruction with Multi-Pass Circular SAR

Abstract:
We consider processing of SAR data collected on multiple complete circular apertures at different elevation angles, for three dimensional target reconstruction. Multipass circular SAR provides wide-angle information about the anisotropic reflectivity of the scattering centers in the scene and provides for three dimensional imaging capability. The 3-D resolution of circular SAR systems is constrained by two factors: the sparse sampling in elevation and the limited azimuthal persistence of the reflectors in the scene. In addition, real flight paths exhibit nonuniform elevation spacing and non-constant elevation throughout the circular pass. We first develop parametric spectral estimation methods that extend standard IFSAR method of height estimation to apertures at more than two elevation angles. We then present a new sparsity regularized interpolation algorithm to preprocess nonuniform elevation samples to create a virtual uniform linear array geometry. We illustrate the performance of the proposed method using simulated backscatter data.