Radar Cross Section Of Complex Targets Research Articles

Metasurface-Based Method for Broadband RCS Reduction of Dihedral Corner Reflectors With Multiple Bounces

A broadband technique to reduce the radar cross section (RCS) of complex targets is presented. In such targets, multiple-bounce mechanism dominates their RCS. The proposed technique demonstrates that by treating the multiple-bounce mechanism as a cascaded phenomenon, the problem then simplifies to identifying and implementing a set of orthogonal functions. Robust guidelines for avoiding grating lobes are provided using array theory. The 90° dihedral corner is used to verify the proposed technique. Measurements are reported for a fabricated prototype with artificial magnetic conductor (AMC) technology where a 70% RCS-reduction bandwidth is observed. To generalize the method, a 45° dihedral corner, with quadruple-bounce mechanism, is considered. Generalized guidelines are summarized and applied to reduce the RCS of complex targets using the proposed method.

Cross section measurements of scale-model tactical targets by using 0.1 THz compact radar system

We present a new compact radar system to measure a terahertz radar cross section (RCS) of metal plates, trihedral corner reflectors, and an aircraft scaled model with a 0.1 THz continuous wave. We both numerically and experimentally investigate the terahertz RCS of the metal plates and trihedral corner reflectors. The numerical simulations are obtained by using commercial software, i.e., computer simulation technology, which agree well with the experimental results. Then, the RCS of an aircraft scaled model is measured, and the experimental results are in good agreement with the physical characteristics of the scaled model. The effectiveness of our compact radar system is verified to get the RCS of complex targets, such as the scaled models of the tactical targets.

RCS of Complex Targets: Original Representation Validated by Measurements—Application to ISAR Imagery

In this paper, we propose and investigate a model based on asymptotic methods, designed to compute the radar cross section (RCS) of complex targets. A combined method of physical optics, geometrical optics, and the equivalent current method is applied to establish an effective backscattering analysis procedure. The scattering model includes shadowing effects, multiple bounce, and diffraction by edges. This model is used for RCS estimation and to generate inverse synthetic aperture radar (ISAR) raw data for imaging applications. We review the theoretical aspects and describe the proposed model and experimental setup in detail. Numerical results are provided and compared with the experimental results obtained in the anechoic chamber of ENSTA Bretagne to validate the approach through the computation of the RCS for canonical objects and a generic boat. Finally, a parallelepiped representation of the RCS is presented to be used for ISAR imagery, and the first results concerning the ISAR imaging of a generic boat are provided.

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

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