High Resolution Frequency Swept Imaging.

Abstract : Target shape estimation in the context of inverse scattering from far field data is a longstanding problem of considerable present day interest. It can be shown from inverse scattering theory that multiaspect (monostatic or bistatic) frequency or impulse response measurements of the far field of a scattering object can be used to access the 3-D Fourier space or p-space of the object. Tomographic or projection images of the scattering object can then be reconstructed from the p-space data based on the projection-slice theorem stemming from the multidimensional Fourier transform. The above principles embody the foundation of 3-D tomographic or projective imaging radars capable of furnishing unprecedented resolution through a judicial combination of angular (spatial), spectral, and polarization diversity. During the period of this report efficient methods for accessing the 3-D Fourier space of conducting and dielectric objects were studied and implemented using a versatile automated microwave measurement and imaging facility.