Extended Propagation-Inside-Layer Expansion Research Articles

A Study of Composite Scattering Characteristics of Movable/Rotatable Targets and a Rough Sea Surface Using an Efficient Numerical Algorithm

The composite electromagnetic scattering characteristics of movable/rotatable targets coexisting with a randomly rough sea surface are studied by the extended propagation-inside-layer expansion (EPILE) combined with the generalized forward-backward method (GFBM). The composite scattering formulation is given. The multiple scattering characteristics related to the self- and mutual coupling of the targets and sea surface under different parameters are numerically implemented and analyzed.

A Study of Composite Electromagnetic Scattering From an Object Near a Rough Sea Surface Using an Efficient Numerical Algorithm

The composite electromagnetic scattering problem from the randomly rough sea surface and an object nearby is effectively analyzed by the Extended Propagation-Inside-Layer Expansion (EPILE) combined with the Forward-Backward method (FBM) scheme. The formulation of the composite scattering is given, the efficiency and accuracy of the adoptive algorithm are verified, and several scattering characteristics under various parameters are numerically analyzed.

A FAST EPILE+FBSA METHOD COMBINED WITH ADAPTIVE CROSS APPROXIMATION FOR THE SCATTERING FROM A TARGET ABOVE A LARGE OCEAN-LIKE SURFACE

The rigorous evaluation of the NRCS (Normalized Radar Cross Section) of an object above a one-dimensional sea surface (2D case) needs to numerically solve a set of discretized integral equations involving a large number of unknowns. Thus, the direct solution of the impedance matrix equation via LU decomposition becomes the most expensive step in the MoM (Method of Moments) procedure. So, in order to minimize the computation cost, the iterative domain decomposition method called EPILE (Extended Propagation-Inside-Layer Expansion) was used and then was combined with the FBSA (Forward-Backward with Spectral Acceleration) to calculate the local interactions on the rough sea surface. The resulting fast method is called EPILE+FBSA. In this paper, we take advantage of the rank-deflcient nature of the coupling matrices, corresponding to the object-surface interactions, to further reduce the complexity of the method by using the ACA (Adaptive Cross Approximation). Thus, the coupling matrices are strongly compressed without a loss of accuracy and the memory requirement is then strongly reduced. For a cylinder above a rough sea surface, the results show the e-ciency of the accelerated EPILE+FBSA+ACA method.

AN INVESTIGATION ON NUMERICAL CHARACTERIZATION OF SCATTERING FROM TARGET IN A DIELECTRIC ROUGH SOIL SURFACE

Based on the Propagation-Inside-Layer Expansion (PILE) and Forward-Backward method (FBM), the composite scattering from the target below a dielectric rough soil surface using the extended PILE (EPILE) combined with the Forward-Backward method (FBM) is studied. The accuracy and e-ciency of the EPILE + FBM for this speciflc type of composite scattering is researched by comparing with the method of moments (MOM), the in∞uences of the target size, target depth, target horizontal distance, the rms height, the correlation length, the incident angle and the soil moisture content, etc., to the bistatic scattering coe-cient (BSC) are also investigated.

Extended propagation-inside-layer expansion method combined with the forward-backward method to study the scattering from an object above a rough surface

In this Letter, a fast red rigorous numerical method, based on the method of moments, is developed to calculate the scattering from an object above a rough surface for three-dimensional problems (3D). G. Kubické has recently developed the extended propagation-inside-layer expansion (E-PILE) method to calculate the scattering from an object above a rough surface for two-dimensional problems. This method allows us to calculate separately and exactly the interactions between the object and the rough surface. The purpose of this paper is to extend the E-PILE method to a 3D problem. In addition, to invert a matrix of large size, the forward-backward (FB) method is applied to calculate the local interactions on the rough surface.

The Fast EPILE Combined With FBM for Electromagnetic Scattering From Dielectric Targets Above and Below the Dielectric Rough Surface

The composite electromagnetic scattering from dielectric targets above and below the dielectric rough surface using the method of moments (MOM) and the Extended Propagation-Inside-Layer Expansion (EPILE) combined with the Forward-Backward method (FBM) is studied. The established integral equations are validated by comparing with the related theory. The efficiency and exactness of the EPILE+FBM are verified by comparing with the MOM. The influences from the target size, the target height/depth, the target horizontal distance, the relative permittivity, the rms height, as well as the correlation length to the bistatic scattering coefficient are also investigated. The presented scheme is of generality for the targets and rough surface composite scattering problems.

A study of electromagnetic scattering from conducting targets above and below the dielectric rough surface

The composite scattering from the conducting targets above and below the dielectric rough surface using the extended Propagation-Inside-Layer Expansion (EPILE) combined with the Forward-Backward method (FBM) is studied. The established integral equations are approved by comparing with the related theory. The accuracy and efficiency of the EPILE + FBM are compared with the method of moments (MOM). The influences of target size, target height/depth, target position, and the rms height, the correlation length, as well as the incident angle on the bistatic scattering coefficient (BSC) for different polarizations are also investigated. The presented algorithm is of generality for the target-rough surface composite scattering problems.

The EPILE Combined With the Generalized-FBM for Analyzing the Scattering From Targets Above and on a Rough Surface

The extended propagation-inside-layer expansion (EPILE) combined with the generalized-forward-backward method (GFBM) for the scattering from multiple targets and a rough surface is presented. The accuracy and the efficiency of the EPILE+GFBM are investigated by comparison to the method of moments (MOM). The influences of the wind speed to the bistatic scattering coefficient (BSC) are also discussed .

Monostatic Radar Cross Section of an object above a sea surface from a rigorous method

Abstract The rigorous computation of the monostatic RCS (Radar Cross Section) of an object above a one-dimensional sea surface (2D case) needs to solve a problem involving a high number of unknowns. Thus, a recently developed fast numerical method, called E-PILE (Extended Propagation-Inside-Layer Expansion), was combined with FB-SA (Forward–Backward with Spectral Acceleration). Two objects are considered in this article: the cross and the cylinder. Results obtained from E-PILE + FB-SA allow us to understand the physical mechanisms involved in the coupling between the object and the sea surface.