A spectral domain ray tracing method for quasi-optical devices modelling

In this paper, an outdoor massive MIMO (Multiple-Input and Multiple-Output) system with $40\times 40$ planer array is simulated based on the SBR (Shooting and Bouncing Ray) method. The propagation characteristics, including PAP (Power Angle Profile), receive power, delay spread and PDP (Power Delay Profile), are studied in both LoS (line-of-sight) and NLoS (non-line-of-sight) links. The near-field effect is also discussed.

Two ray shooting methods for computing the EM scattering by large open-ended cavities

This paper analyzes the scattering characteristics of the hypervelocity models with the shooting and bouncing rays (SBR). The algorithm provides a reliable treatment to measure the object with electrically large size covered by inhomogeneous plasma sheath. The numerical results indicate that covering with plasma sheath will change the value of RCS of the hypervelocity. And the inhomogeneous plasma sheath also has great influence on the RCS result.

A new efficient hybrid technique is presented, which combines the method of moments (MoM) and the shooting and bouncing ray (SBR) for analyzing scattering of complex large structures. By applying the SBR method for the whole structures, a corrected incident field including not only the direct incident field but also the multi-bounce field from the SBR region contributes to the integral equation in the MoM region. For the SBR region, it also considers the interaction from MoM region and then a physical optics (PO) type integration is performed to calculate the scattered field. For complex electrically large electromagnetic problems, the proposed technique is more efficient and simpler to implement in a general-purpose computer code. Numerical results are presented to show the efficiency and accuracy of the method.

Vehicle-to-vehicle (V2V) communications require highly accurate and real-time channel modeling techniques. The dynamic nature of V2V scenarios demands continuous scene updates while ray-tracing (RT) algorithms typically require substantial computational time to achieve accurate predictions. This letter proposes an OptiX-based GPU-parallel dynamic shooting and bouncing ray tracing (DSRT) method that combines the advantages of shooting and bouncing ray (SBR) and RT approaches. The method employs an improved adaptive ray-tube splitting mechanism to improve accuracy. A level of detail (LOD)-based dynamic scene update method further optimizes performance, while OptiX and CUDA acceleration enable efficient RT. Channel measurements in urban environments demonstrate the high accuracy of our algorithm. Performance evaluation results show that DSRT achieves a parallelization degree exceeding 98.8% and delivers exceptional speedup ratios.

Triangular ray tubes in electromagnetic scattering calculation using shooting and bouncing ray (SBR)

The site-specific radio wave propagation prediction in outdoor is increasingly important for electromagnetic interference analysis. Since the outdoor environment is usually very complex and electrically large, the shooting and bouncing ray (SBR) method (one technique of ray tracing) rather than other numerical methods such as finite difference time domain method and finite element method, is often applied in the computation. However, a large amount of rays have to be launched to guarantee the accuracy in conventional ray tracing methods. This, in turn, increases the simulation time significantly. Recently, many acceleration algorithms have been reported including space partitioning and wavefront decomposition. This paper presents a novel adaptive ray launching (ARL) method based on the pattern of transmitting antenna, which reduces the launched ray number significantly while maintaining the computation accuracy

In the paper, high resolution range profile (HRRP) of a target above rough ground is analyzed based on the scattered echo data. The electromagnetic scattering of composite model is solved by the hybrid method of physical optics (PO)- shooting and bouncing ray (SBR). And an octree data structure is used to accelerate the ray tracing progress. The bistatic electromagnetic scattering of a reduced-scale vehicle target above rough ground is calculated by our method and compared with the simulation result with MLFMM in FEKO. Then by inverse Fourier transform of backscattering echo data, the range profile of composite model is obtained.

Radar detectability reducing for complex shape military or civil object is very important problem of contemporary radar theory. Solution of this problem is unthinkable without providing numerical estimations of the investigated object Radar Cross Section (RCS) and its reduction with some cloak. In this paper a new method for the semitransparent cloak modeling is proposed. This method is realized in the framework of Shooting and Bouncing Ray (SBR) method. General stages of SBR method and the cloak modeling introduction into its algorithm are discussed. The proposed approach was tested on an example of complex shape object.

This letter proposes new usage of the binary tree constructed by fundamental GO ray components in shooting and bouncing rays (SBR) for indoor propagation analysis. The node number of the binary tree is here considered as an important parameter. A couple of small size arrays that can store the passing ray information of both the node number and the position of the pixel considered, and the corresponding ray classification algorithm are newly introduced, not to double-count the same ray with slightly different bouncing angle. Consequently, we realize the big reduction of the computer memory resources consumed for the ray classification especially for wide area analysis, keeping the high accuracy of the SBR method.

Prediction of urban sound propagation is an integral part for the assessment of noise levels in cities. Several propagation modeling methods exist to predict sound propagation in city environments including parabolic equation, diffusion equation, radiosity, ray tracing, image source, modal analysis, and transmission line matrix methods. For this study, adaptive beam tracing as a geometrical acoustic prediction method is applied in the context of predicting sound propagation in complex urban environments. Adaptive beam tracing is advantageous compared to the ray tracing and image source methods by eliminating aliasing errors and spurious image sources, respectively. A model of diffraction [Svensson et al., J. Acoust. Soc. Am. 106, 2331–2344 (1999)] is integrated with the adaptive beam tracing algorithm in order to enhance the prediction capability of the proposed method. The effects of facade roughness, street canyon shielding, and building spacing are investigated. Comparison of the proposed method is made with a ray tracing method. Computation times, as well as various geometric configurations, are compared between the proposed method and the ray tracing method.

We present a method to generate three-dimensional (3D) inverse synthetic aperture radar (ISAR) images of a target at arbitrary aspect angles using the shooting and bouncing ray (SBR) method. We have derived a 3D-image-domain ray-tube integration formula based on the SBR technique. The imaging formula is in a form of convolution, then a nonuniform fast Fourier transform (NUFFT) is induced to achieve the convolution, which can be used to generate 3D ISAR images rapidly. Compared to the conventional algorithm where the ISAR images are obtained by inverse Fourier transforming the computed scattered fields over a range of frequencies and a range of aspect angles, the new formula needs only one-time ray tracing and physical optics (PO) integration over a small angle span. Hence the computational time is decreased tremendously. The ISAR images of a missile target and an armored car for several aspect angles are presented to demonstrate the efficiency and accuracy of the proposed method.

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.

For the electromagnetic modeling of scattered fields from large and complex objects, a very efficient simulation tool based on the well-known Shooting-and-Bouncing-Rays (SBR) technique has been developed [1]. This algorithm uses field-based high-frequency approaches for finding the relevant propagation paths, i.e. rays are traced through the scenario according to the laws of Geometrical Optics (GO) and diffracted rays are generated according to the laws of the Uniform Theory of Diffraction (UTD). This GO/UTD part is combined with a source-based approach, where each ray generates an equivalent surface current at each interaction with the object. These currents are calculated using Physical Optics (PO) and Physical Theory of Diffraction (PTD), and the superposition of all these contributions leads to the total scattered field strengths. Further technical details about the ray tracing approach can be found in [1, 2, 4]. With this simulation tool, large and complex objects can be modeled, which are still too costly for numerically exact methods. Generally, both metallic and dielectric objects [2], and also combined metallic-dielectric objects, can be modeled.

A modeling method for synthetical scene based on the electromagnetic model