A 3D Polar Processing Algorithm for Scale Model UHF ISAR Imaging

In recent years, UHF synthetic aperture radar has become a growing area of interest among the radar community. Due to their relatively long wavelengths, UHF systems provide advantages that may not be attainable by microwave and millimeter-wave radar systems. These advantages include excellent target detection statistics in high clutter environments, wide-area surveillance, and long stand-off ranges. UHF systems also have proven synergistic properties with higher frequency radar systems in applications such as topographical mapping. However, the ability to study the characteristics of these lower frequency radar systems in a controlled and systematic environment is difficult. In this work, a physical scale modeling process is utilized to generate three-dimensional UHF imagery that may be used to study scattering phenomenology at these wavelengths. Dimensionally and dielectrically scaled targets and scenes are measured in a 6 – 18 GHz microwave compact range to model the backscatter of the full-size target at UHF wavelengths. The microwave compact radar range and transceiver hardware utilized to model UHF radar signature data are briefly described. A description of the image processor used to generate three-dimensional UHF imagery from wide-band/wide-angle data collections is described as well. Finally, imagery of radar signature data collected from a M1A1 Abrams main battle tank model is examined. The high resolution imagery resulting from the wide-band/wide-angle collection will show that sub-wavelength features of ground targets are resolvable at these wavelengths.