An Accelerated Hybrid Method for Electromagnetic Scattering of a Composite Target–Ground Model and Its Spotlight SAR Image

Abstract

In this paper, an accelerated hybrid method of physical optics (PO) shooting and bouncing ray (SBR)–physical theory of diffraction (PTD) is proposed to deal with the electromagnetic scattering of a complex target on rough ground. To accelerate the ray tracing progress, the ray marching technique based on octree structure is employed. In this technique, only the nodes passed by the ray are detected successively until the first facet intersected by ray is found or the ray passes through the bounding box, which greatly decreases the intersection test. Then, based on the accelerated PO-SBR-PTD method, the spotlight synthetic aperture radar (SAR) echo data of the composite target–ground model is obtained by the vector superposition of the echo on each meshed patch. Furthermore, the spotlight SAR image of the composite model is simulated by the polar format algorithm (PFA). In numerical simulations, both the EM scattering of the target and composite model are calculated and evaluated by comparing with the multilevel fast multipole method (MLFMM) in FEKO software. Meanwhile the spotlight SAR image of the composite target–ground model is also compared with the real image in MSTAR data, and a satisfactory similarity between them is obtained. In addition, the SAR images of two targets on rough ground for different pose angles are also presented and analyzed.

High-Precision GPU-Accelerated Simulation Algorithm for Targets under Non-Uniform Cluttered Backgrounds

“…In order to validate the accuracy of this simulation method, we opted to compare our results with those presented in reference [23]. However, due to the unavailability of an exact ZSU-23 digital model in our laboratory, we selected the T62 tank as our simulated target and compared its simulation results with the measured data from the MSTAR dataset.…”

“…The signal parameters of the MSTAR simulation are presented in Table 1. The comparison between the simulation results of reference [23] and the MSTAR data is illustrated in Figure 12. φ a denotes the azimuth angle of the target.…”

“…However, this application only focuses on target simulation and does not consider the impact of targets in the scene. In [23], the authors proposed an electromagnetic scattering simulation technique based on a hybrid method, which is used to study the characteristics of composite target-ground models. However, this method modifies the target's 3D structure directly to obtain the target's state on the ground and uses SBR to obtain SAR imaging of the small area of the target and ground.…”

A Fast Coupled Iterative Approach for Computing 3D Composite Scattering from Dielectric Rough Surfaces and Target

“…The study of target and environmental electromagnetic scattering characteristics is a very important and widely used topic in the field of remote sensing and monitoring. In recent years, with the rapid development of radar remote sensing and target detection technology, the study of target and environmental electromagnetic scattering characteristics [17][18][19][20][21][22][23][24] has received more and more extensive attention from scholars.…”

Composite electromagnetic scattering and SAR imaging of the topographical environment

“…Radar is widely used in the military and civilian fields due to its all-day and all-weather operation in target detection [1], environmental monitoring [2], battlefield assessment [3], and electromagnetic imaging [4]. Since the middle of the last century, foreign scholars have carried out a large number of radar ground and sea observation experiments, and battlefield environment monitoring.…”