Ground-based reflector antennas observed with space-based Synthetic Aperture Radar

Recent space-based Synthetic Aperture Radar (SAR) observations are discussed of large reflector antennas on the ground. The results are elaborated with suggestions for further work to arrive at more precise information. Such targets might eventually receive further attention in applications with SAR operating at lower frequency than for which the ground-station antenna operates. Being below cut-off, the antenna becomes a passive scattering structure with a Radar Cross Section (RCS). Such antenna may function as stable target of opportunity, additional to transponders. Its response should be stable (even in complex vectorial sense). Precise prediction requires accurate modelling. A target is automatically available (“free of charge”), when the low-frequency SAR instrument is switched on over the ground-station antenna for data downloading and when the latter antenna is located within the SAR image coverage.