Use of radio telescopes or satellite Earth station antennas as ultra-high scattering cross-section calibration targets for spaceborne remote sensing radars

Spaceborne synthetic aperture and scatterometer radars currently under development for Earth remote sensing may require the provision of ground calibration targets with very large scattering cross-sections. One way of providing these would be to adapt existing parabolic radio telescopes or satellite Earth station antennas by replacing the feed by a metallic sphere. A dichroic surface would facilitate tracking.