Research on the Composite Electromagnetic Scattering of Rough Surface and Buried Target Based on G-PILE

This article proposes a G-PILE (Generalized Propagation Inside Layer Expansion) algorithm for solving the composite electromagnetic scattering of large-scale dielectric rough surfaces and buried dielectric targets. Firstly, the EFIE (Electric Field Integral Equation) is established, and the traditional PILE algorithm is improved to extend its application to studying the composite scattering characteristics of targets under rough surfaces. In the iterative process, the BMIA/CAG (Banded Matrix Iterative Approach Canonical Grid) is introduced to solve the electromagnetic scattering of the rough surface itself, ultimately reducing the complexity of the algorithm to O(N log N) and achieving acceleration. Meanwhile, a conical incident wave is introduced to reduce the error caused by rough surface truncation. To verify the accuracy of G-PILE, the scattering characteristics of a dielectric cylinder buried under a dielectric rough surface are calculated and compared with existing algorithms. The effectiveness of G-PILE is demonstrated in several aspects. Results show that the algorithm gets excellent performance in accuracy and computation efficiency. Finally, the composite electromagnetic scattering depending on different target parameters is studied. These results are of great significance for understanding and predicting the interaction between rough ground and targets as well as the changes in scattering coefficients.