Bistatic RCS Calculations From Cylindrical Near-Field Measurements—Part II: Experiments

Abstract

Bistatic radar cross section (RCS) is computed from cylindrical near-field measurements obtained in a radio anechoic chamber with the target illuminated by a compact-range reflector. Near-field measurement is convenient where the RCS of complex targets is not amenable to computation or where computational results require experimental confirmation. A companion paper addresses the theory of cylindrical near-field scanning with reference to our experimental system. RCS of canonical targets derived from near-field measurement are in good agreement with theory. This paper compares the far fields computed from the near-field measurements with numerical solutions. Separating the target-scattered fields from incident and background fields presents a major challenge in an indoor bistatic radar configuration. We discuss the errors introduced by a residue of the incident field that is not canceled by the background subtraction method currently in use. A slow drift in system parameters and probe column oscillations are among the contributing factors