Near-field Measurement of Target RCS Based on ISAR Imaging and Scattering Center Extraction

keywords:radar scattering cross section  2D ISAR imaging  near-field measurement  probe compensation  CLEAN algorithm

Abstract:In this paper, the effective measurement of the target radar scattering cross section (RCS) area at the near-field test distance is achieved by combining inverse synthetic aperture radar ( ISAR) imaging and scattering center extraction techniques.The near-field spherical wave correction technique and probe compensation technique are used to reduce the effect of near-field spherical wave effect and transceiver probe on the imaging quality. The scattering center extraction technique is applied to the target ISAR image to eliminate the side-lobe effect caused by the limited bandwidth in the target ISAR image and to reduce the data storage requirement. The selection criterion of the truncation threshold in the scattering center extraction is studied in depth, and the empirical formula for the determination of the truncation threshold is given and validated with simulation experiments. Finally, the chamber near-field measurements of standard spherical cone scatterers were used to validate the method studied in this paper, and the results agreed well with the multilayer fast multipole simulations, which verified the effectiveness of the proposed method.