Radiation center representation of antenna synthetic aperture radar (ASAR) images

It is well known that antenna characteristics can be dramatically affected by the presence of platforms that support the antenna structure. Previously, we have introduced an imaging algorithm called antenna synthetic aperture radar (ASAR) that images the locations of the dominant scattering off the platform from antenna radiation data. Such information is useful to the antenna designer in understanding the cause-and-effect relationship in platform scattering. In this work, we present a sparse representation of platform scattering by extracting a point scatterer representation of the ASAR image. Similar to an ISAR image, an ASAR image exhibits strong point-scatterer-like behaviour. In the ISAR case, these points are called scattering centers In our case, we call them radiation centers since they are in fact the secondary point radiation centers. Next, we show that we can reconstruct and extrapolate the antenna radiators on the platform. First, we use the well known CLEAN algorithm to extract the radiation data in frequency and aspect with good fidelity by using the radiation centers. Finally, we demonstrate that the radiation center information can be used to provide important guidelines for reducing platform effects.