Improved Near-Field ISAR Imaging Algorithm for Far-Field Radar Cross Section Measurement

The measurement of radar cross section (RCS) is of great significance to the development and maintenance of large stealth military targets. The traditional test method is based on target imaging. In the near field, the traditional imaging algorithm is no longer effective. An RCS measurement method based on two-dimensional near-field inverse synthetic aperture radar (ISAR) spherical wave imaging algorithm is proposed. The algorithm calculates the “focusing operator” of each pixel in the image, and then reproduces all scattering points of the target by numerical integration. Finally, the RCS of the target is calculated by Geometric Theory of Diffraction (GTD)-based algorithm. Simulation results show that the proposed algorithm can obtain accurate image of target, and its RCS calculation accuracy is high for low scattering target, and it has high practicability.