  Radio-telescopes or ground-station antennas can, if pointed, act as a radar
target with high radar cross-section (RCS). Space-based Synthetic Aperture
Radar (SAR) data confirmed it at 5:3GHz for a modified ground-station antenna.
Operational ground-station antennas cannot be modified. The latter antennas
might operate at frequencies well above the radar band. The radar signal could
be scattered with high RCS from such an antenna, with less influence due to a
load (receiver). The antenna geometry should be precisely known to derive its
RCS. BIOMASS SAR operates near 435 MHz (P-band). Results are given, also for
BIOMASS antenna itself. Large antennas in an array as in Westerbork are of
potential interest, located on an East-West line, nearly perpendicular to
ascending and descending polar orbits. Related material is discussed.
