Abstract
In this paper, an improved hybrid scheme combining the method of moment (MoM) and physical optic (PO) is proposed to analyze composite scattering from multiple 3D conductingobjects above a 2D random rough dielectric surface. In the calculation scheme, rough surface scattering is calculated using the PO method and target scattering is calculated by the MoM. The coupling interactions between the multiple targets are considered using the domain distribution method (DDM), where the matrix equations are constructed upon each individual target and are then presented and solved as a whole. The contribution from rough surface scattering, which is calculated by the PO method, is coupled with the impedance matrix, and the unknowns must be considered only in the MoM region. Most of the composite scattering problems are computing interactions between objects and rough surface, and solving the complex impedance matrix equation in the MoM part. To solve these two problems, first, the combined multilevel fast multipole algorithm (MLFMA) and the fast far field approximation (FaFFA) are introduced to accelerate interactions between objects and rough surface, where the near area on the rough surface is computed by MLFMA, while the far area is computed by FaFFA. In addition, to further improve the efficiency, the adaptive integral method (AIM) is employed to solve the impedance matrix equation of the MoM part in the scheme. The results are compared to those obtained with the traditional MoM-PO method, showing that the hybrid method proposed in this paper can maintain a high accuracy with a much smaller computational time and fewer resource requirements. The numerical results obtained under several different conditions are presented and discussed in this paper.
Highlights
Composite scattering from multiple targets above a rough surface has been widely used in applications, such as navigation for multiple aircraft and detection of an important target among multiple targets in the air, and in other areas [1]–[6]
Among the studies of composite scattering from multiple targets with a rough surface reported in the literature, Ref. [7] studied composite scattering from multiple targets above and on a rough surface, and Ref. [8] computed composite scattering from multiple targets above and below a dielectric rough surface
As the root mean square (RMS) increases, the accuracy of the imposed method worsens, especially at large incident angles. The reason for this lies in that the mutual interaction becomes stronger when the RMS increases and the imposed method ignores it. These results show that this proposed method has limitations, especially for rough surfaces with large RMS heights
Summary
Composite scattering from multiple targets above a rough surface has been widely used in applications, such as navigation for multiple aircraft and detection of an important target among multiple targets in the air, and in other areas [1]–[6]. A method combining compressive sensing and the MoM [17] and a method based on compute unified device architecture (CUDA) [18] are used to further accelerate the MoM These methods are not suitable for calculating composite scattering from electrically large targets above a rough surface because the computational complexity increases strongly with increasing numbers of unknowns in the composite model. [24], Ye used the iterative KA-MoM technique to study scattering from a 3D target above a rough dielectric surface with the MoM part accelerated by using the conjugate gradient (CG) method. For the MoM-PO method, unknowns are only required in the MoM area, greatly reducing the storage requirements This approach considers all of the scattering contributions from the targets and the rough surface, guaranteeing the accuracy of this method. The wavelength of the incident field must be less than the radius of curvature at the object surface
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
