Impact of the target supporting mast in an indoor RCS measurement facility: Computation and measurement

Indoor RCS measurement facilities are usually dedicated to the characterization of only one azimuth cut and one elevation cut of the full spherical RCS target pattern. In order to perform more complete characterizations, a spherical experimental layout has been developed at CEA for indoor Near-Field monostatic RCS assessment. This experimental layout is composed of a 4 meters radius motorized rotating arch (horizontal axis) holding the measurement antennas while the target is located on a mast (polystyrene or Plexiglas) mounted on a rotating positioning system (vertical axis). The combination of the two rotation capabilities allows full 3D Near-Field monostatic RCS characterization. The main measurement errors are due to the near field illumination, and the influence of the mast on the measured RCS. The first one has been addressed in a previous paper [4]. This paper investigates the influence of the material of the mast supporting the target under test. RCS measurements results of a canonical target are compared to the simulation of its RCS taking account both the near-field illumination and the presence of the supporting mast.