Monostatic Radar Cross Section Near-Field Far-Field Transformations by Multilevel Plane-Wave Decomposition

Retrieving far-field radar cross-section information from near-field data is a well-established methodology. However, existing algorithms impose many restrictions on the underlying measurement procedure. In this paper, algorithms are presented which are based on plane-wave decompositions and hierarchical groupings. Consequently, arbitrarily located monostatic near-field samples with arbitrary polarization information can be processed with full consideration of the radar antenna characteristics, where the computational complexity is identical to other fast approaches. The method uses scattering coefficients based on a Cartesian plane-wave scattering matrix as unknowns for the solution of the transformation problem. With this matrix description, the complete polarimetric information is obtained with a single transformation. Numerical examples are given to prove the usefulness of the algorithm.