ISAR imaging of space objects using large observation angles

Abstract

Ground based imaging of satellites using an inverse synthetic aperture radar (ISAR) is a very powerful method for space surveillance. Based on the high resolution ISAR images, a precise evaluation of satellite structures can be derived. Hereby the achieved spatial resolution in azimuth direction depends on the integration angle considering a given radar transmit frequency. Further on, a significant larger observation angle, compared to the needed azimuth integration angle, can bring additional information content to the ISAR image. Especially due to the fact, that a large observation angle triggers much more scattering points during the illumination. Considering large observation angles in the subsequent image processing step, the acquired data can either be processed to one single ISAR image, representing a large integration angle, or to a stack of ISAR images showing the object from different perspectives. The paper outlines the possibilities and advantages of ISAR imaging using large observation angles based on real measurement data.