Measurements and predictions of the RCS of Bruderhedrals at millimeter wavelengths

Polarimetric radar cross sections (RCSs) were measured for two large Bruderhedrals at 35 and 93 GHz. The overall spread in the measured RCS was 2 dB. It was found that the absolute RCS as well as the dependence of the RCS on elevation angle could be significantly altered by a slight misalignment of the Bruderhedral. The calculations of these RCSs by theories for a top hat and RCS simulation codes based on geometric and physical optics (PO) generally agreed with the measurements to within 3 db. Radar calibrations using these Bruderhedrals that are based on the predictions are not reliable, however, if accuracies better than 3 dB are required, The measured values of the cross-polarization RCS were very small compared to the copolarization ones, consistent with the codes and theoretical considerations.