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Статті в журналах з теми "Ray-tracing modelling"

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Автор: Grafiati

Опубліковано: 10 грудня 2022

Оновлено: 28 січня 2023

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1

Kamaruddin, Mohd Nazeri, Tan Kim Geok, Omar Abdul Aziz, Tharek Abd Rahman, Ferdous Hossain, and Azlan Abdul Aziz. "Adaptive 3D ray tracing approach for indoor radio signal prediction at 3.5 GHz." International Journal of Electrical and Computer Engineering (IJECE) 12, no. 2 (April 1, 2022): 1617. http://dx.doi.org/10.11591/ijece.v12i2.pp1617-1625.

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This paper explained an adaptive ray tracing technique in modelling indoor radio wave propagation. As compared with conventional ray tracing approach, the presented ray tracing approach offers an optimized method to trace the travelling radio signal by introducing flexibility and adaptive features in ray launching algorithm in modelling the radio wave for indoor scenarios. The simulation result was compared with measurements data for verification. By analyzing the results, the proposed adaptive technique showed a better improvement in simulation time, power level and coverage in modelling the radio wave propagation for indoor scenario and may benefit in the development of signal propagation simulators for future technologies.

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2

Hossain, Ferdous, Tan Geok, Tharek Rahman, Mohammad Hindia, Kaharudin Dimyati, Chih Tso, and Mohd Kamaruddin. "A Smart 3D RT Method: Indoor Radio Wave Propagation Modelling at 28 GHz." Symmetry 11, no. 4 (April 9, 2019): 510. http://dx.doi.org/10.3390/sym11040510.

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This paper describes a smart ray-tracing method based on the ray concept. From the literature review, we observed that there is still a research gap on conventional ray-tracing methods that is worthy of further investigation. The herein proposed smart 3D ray-tracing method offers an efficient and fast way to predict indoor radio propagation for supporting future generation networks. The simulation data was verified by measurements. This method is advantageous for developing new ray-tracing algorithms and simulators to improve propagation prediction accuracy and computational speed.

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3

AL-Behadili, Hasanain A. H., Mohsin Najim Sarayyih Almaliki, and Saddam K. Alwan AlWane. "A Ray Tracing Model for Wireless Communications." International Journal of Interactive Mobile Technologies (iJIM) 13, no. 11 (November 15, 2019): 245. http://dx.doi.org/10.3991/ijim.v13i11.11730.

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<p>Recently, there has been an interest in modelling of the communication process. One of the most important reasons for developing such models is to forecast what will be happened. A number of modelling studies provide several assumptions and use different theories. up to now, there is still a lack of an optimum model which can be used for the purpose of future communications. This indicates a need to understand the aspects of communication modelling and the motivation behind improving our knowledge in this field. This paper details work done to design a propagation model of a wireless communication system to give a forecast of signal behavior. Data for this study were collected using a wireless communication system employed in the outdoor environment. The final part of this paper gives a summary and description of findings which include a comparison between the experimental and simulation results. The model finally shows a similar trend with the observation.</p>

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4

Flandes, Alberto, Ángel M. García-Reyes, and Linda Spilker. "Ray-tracing thermal modelling of Saturn's main rings." Icarus 354 (January 2021): 114063. http://dx.doi.org/10.1016/j.icarus.2020.114063.

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5

Novak, Roman, Andrej Hrovat, Michael D. Bedford, and Tomaž Javornik. "Geometric Simplifications of Natural Caves in Ray-Tracing-Based Propagation Modelling." Electronics 10, no. 23 (November 25, 2021): 2914. http://dx.doi.org/10.3390/electronics10232914.

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Natural caves show some similarities to human-made tunnels, which have previously been the subject of radio-frequency propagation modelling using deterministic ray-tracing techniques. Since natural caves are non-uniform because of their inherent concavity and irregular limestone formations, detailed 3D models contain a large number of small facets, which can have a detrimental impact on the ray-tracing computational complexity as well as on the modelling accuracy. Here, we analyse the performance of ray tracing in repeatedly simplified 3D descriptions of two caves in the UK, i.e., Kingsdale Master Cave (KMC) Roof Tunnel and Skirwith Cave. The trade-off between the size of the reflection surface and the modelling accuracy is examined. Further, by reducing the number of facets, simulation time can be reduced significantly. Two simplification methods from computer graphics were applied: Vertex Clustering and Quadric Edge Collapse. We compare the ray-tracing results to the experimental measurements and to the channel modelling based on the modal theory. We show Edge Collapse to be better suited for the task than Vertex Clustering, with larger simplifications being possible before the passage becomes entirely blocked. The use of model simplification is predominantly justified by the computational time gains, with the acceptable simplified geometries roughly halving the execution time given the laser scanning resolution of 10 cm.

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6

Disney, M. I., P. Lewis, and P. R. J. North. "Monte Carlo ray tracing in optical canopy reflectance modelling." Remote Sensing Reviews 18, no. 2-4 (September 2000): 163–96. http://dx.doi.org/10.1080/02757250009532389.

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7

García-Reyes, Ángel M., and Alberto Flandes. "Methods for ray-tracing thermal modelling of Saturn's main rings." MethodsX 8 (2021): 101457. http://dx.doi.org/10.1016/j.mex.2021.101457.

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8

Hassan-Ali, M., and K. Pahlavan. "Site-specific wideband indoor channel modelling using ray-tracing software." Electronics Letters 33, no. 23 (1997): 1983. http://dx.doi.org/10.1049/el:19971318.

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9

Friebel, Björn, Michael Schweins, Nils Dreyer, and Thomas Kürner. "Simulation of GPS localisation based on ray tracing." Advances in Radio Science 19 (December 17, 2021): 85–92. http://dx.doi.org/10.5194/ars-19-85-2021.

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Abstract. In recent years, many simulation tools emerged to model the communication of connected vehicles. Thereby, the focus was put on channel modelling, applications or protocols while the localisation due to satellite navigation systems was treated as perfect. The effect of inaccurate positioning, however, was neglected so far. This paper presents an approach to extend an existing simulation framework for radio networks to estimate the localisation accuracy by navigation systems like GPS, GLONASS or Galileo. Therefore the error due multipath components is calculated by ray optical path loss predictions (ray tracing) considering 3D building data together with a well-established model for the ionospheric error.

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10

Iversen, Einar, Bjørn Ursin, Teemu Saksala, Joonas Ilmavirta, and Maarten V. de Hoop. "Higher-order Hamilton–Jacobi perturbation theory for anisotropic heterogeneous media: dynamic ray tracing in ray-centred coordinates." Geophysical Journal International 226, no. 2 (April 15, 2021): 1262–307. http://dx.doi.org/10.1093/gji/ggab152.

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SUMMARY Dynamic ray tracing is a robust and efficient method for computation of amplitude and phase attributes of the high-frequency Green’s function. A formulation of dynamic ray tracing in Cartesian coordinates was recently extended to higher orders. Extrapolation of traveltime and geometrical spreading was demonstrated to yield significantly higher accuracy—for isotropic as well as anisotropic heterogeneous 3-D models of an elastic medium. This is of value in mapping, modelling and imaging, where kernel operations are based on extrapolation or interpolation of Green’s function attributes to densely sampled 3-D grids. We introduce higher-order dynamic ray tracing in ray-centred coordinates, which has certain advantages: (1) such coordinates fit naturally with wave propagation; (2) they lead to a reduction of the number of ordinary differential equations; (3) the initial conditions are simple and intuitive and (4) numerical errors due to redundancies are less likely to influence the computation of the Green’s function attributes. In a 3-D numerical example, we demonstrate that paraxial extrapolation based on higher-order dynamic ray tracing in ray-centred coordinates yields results highly consistent with those obtained using Cartesian coordinates. Furthermore, in a 2-D example we show that interpolation of dynamic ray tracing quantities along a wavefront can be done with much better consistency in ray-centred coordinates than in Cartesian coordinates. In both examples we measure consistency by means of constraints on the dynamic ray tracing quantities in the 3-D position space and in the 6-D phase space.

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11

Chan, T. M., and W. M. To. "Modelling of Scattering from Balcony Fronts." Building Acoustics 9, no. 3 (September 2002): 219–31. http://dx.doi.org/10.1260/135101002320815684.

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Balconies are normally used in large auditoria such as concert halls or opera houses, to increase seating capacity or to give better view for a distinguished group of the audience. When ray-tracing based computer models are applied to study the acoustical quality of these auditoria, the alteration of the sound field due to balcony fronts is normally unobservable, because of the relative small size of the balcony fronts in the auditorium. Furthermore, most diffuse reflection ray-tracing methods are not based on direct wave acoustics but on an approximation of the scattering effect. In practice, experience shows that balcony fronts give additional warmth to music. This effect is more prominent when singers perform in traditional horseshoe shaped opera houses with multi-levels balconies. This paper describes modelling of scattering from balcony fronts using a theoretical wave approach, in which the incident wave front is not plane but spherical. A computer simulation illustrates the scattering of sound that takes place when the wavefront impinges on the surface of the balcony fronts.

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12

Oliveira, Saulo P., Juarez S. Azevedo, Wilson M. Figueiró, Rodrigo A. Guimarães, Winicius J. Silva, and Andressa de Oliveira. "Representation of discontinuous seismic velocity fields by sigmoidal functions for ray tracing and traveltime modelling." Geophysical Journal International 224, no. 1 (October 2, 2020): 435–48. http://dx.doi.org/10.1093/gji/ggaa476.

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SUMMARY Wave-modelling methods based on asymptotic ray theory have a lower computational cost than full wave-equation methods but require a smooth velocity field, though discontinuities may be handled by imposing interface conditions between adjacent blocks. We propose to approximate discontinuous velocity fields with model parametrizations based on smooth, rapidly varying functions known as sigmoidal functions. We have implemented the proposed technique on Cartesian grids using the wavelet theory formalism. Numerical experiments with 2-D and 3-D initial-value and two-point ray tracing in heterogeneous media show that the ray paths and traveltimes produced with the sigmoidal representation are consistent with the results produced by conventional ray tracing in block structures, broadening the scope of classical algorithms based on smooth velocity fields.

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13

Yulita, D., M. I. R. Putra, S. U. Dini, Erlina, Jessika, A. Pradana, M. Handayani, and I. Anshori. "Simple Qualitative Modelling of Particle Size Analysis using Ray Tracing Method." Journal of Physics: Conference Series 2243, no. 1 (June 1, 2022): 012083. http://dx.doi.org/10.1088/1742-6596/2243/1/012083.

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Abstract Understanding particle size analysis is essential for pharmaceutical, mining, environmental, coatings, and other industries. Although there are numerous technologies that can be utilized to take particle size measurements, the results of those measurements are presented automatically and are sometimes difficult to understand. In this study, using the ray-tracing method, simple qualitative modelling of particle size analysers can be developed. The laser is positioned as the initial position of the light source in x and y directions. The cell is pictured by cuvettes with four surfaces clear, and the particle is modelled as a sphere. Reflection of a single ray of the laser beam on many spheres can be performed using single ray reflection on a single sphere consecutively until the beam leaving the observation region or arriving at a light sensor. Then with vector formulation of ray direction after reflection on many spheres system n ^ r we can define n ^ r , n = n ^ i , n − 1 − 2 ( n ^ i , n − 1 . n ^ p , n ) n ^ p , n with n = 1,2,3,… where n ^ r , 0 = n ^ i . As a test of the particle size analysis model, the results are compared with measurements of the monodisperse polystyrene latex. Interesting patterns in FFT and autocorrelation function results are found. Unfortunately, this finding is still considered inconclusive, due to the pattern obtained is not completely like the experimental results.

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14

Epstein, M., D. Peter, and M. A. Slawinski. "Combining Ray-Tracing Techniques and Finite-Element Modelling in Deformable Media." Quarterly Journal of Mechanics and Applied Mathematics 65, no. 1 (January 11, 2012): 87–112. http://dx.doi.org/10.1093/qjmam/hbr021.

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15

Tiberi, G., S. Bertini, A. Monorchio, F. Giannetti, and G. Manara. "Computationally efficient ray-tracing technique for modelling ultrawideband indoor propagation channels." IET Microwaves, Antennas & Propagation 3, no. 3 (2009): 395. http://dx.doi.org/10.1049/iet-map.2008.0026.

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16

Li, Zhen, Marek Ziebart, Santosh Bhattarai, David Harrison, and Stuart Grey. "Fast solar radiation pressure modelling with ray tracing and multiple reflections." Advances in Space Research 61, no. 9 (May 2018): 2352–65. http://dx.doi.org/10.1016/j.asr.2018.02.019.

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17

Iversen, Einar, Bjørn Ursin, Teemu Saksala, Joonas Ilmavirta, and Maarten V. de Hoop. "Higher-order Hamilton–Jacobi perturbation theory for anisotropic heterogeneous media: transformation between Cartesian and ray-centred coordinates." Geophysical Journal International 226, no. 2 (April 15, 2021): 893–927. http://dx.doi.org/10.1093/gji/ggab151.

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SUMMARY Within the field of seismic modelling in anisotropic media, dynamic ray tracing is a powerful technique for computation of amplitude and phase properties of the high-frequency Green’s function. Dynamic ray tracing is based on solving a system of Hamilton–Jacobi perturbation equations, which may be expressed in different 3-D coordinate systems. We consider two particular coordinate systems; a Cartesian coordinate system with a fixed origin and a curvilinear ray-centred coordinate system associated with a reference ray. For each system we form the corresponding 6-D phase spaces, which encapsulate six degrees of freedom in the variation of position and momentum. The formulation of (conventional) dynamic ray tracing in ray-centred coordinates is based on specific knowledge of the first-order transformation between Cartesian and ray-centred phase-space perturbations. Such transformation can also be used for defining initial conditions for dynamic ray tracing in Cartesian coordinates and for obtaining the coefficients involved in two-point traveltime extrapolation. As a step towards extending dynamic ray tracing in ray-centred coordinates to higher orders we establish detailed information about the higher-order properties of the transformation between the Cartesian and ray-centred phase-space perturbations. By numerical examples, we (1) visualize the validity limits of the ray-centred coordinate system, (2) demonstrate the transformation of higher-order derivatives of traveltime from Cartesian to ray-centred coordinates and (3) address the stability of function value and derivatives of volumetric parameters in a higher-order representation of the subsurface model.

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18

Shield, B. M., and L. N. Yang. "Two Methods of Modelling a Curved Surface in a Ray Tracing Model." Building Acoustics 5, no. 2 (June 1998): 69–78. http://dx.doi.org/10.1177/1351010x9800500201.

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This paper describes two methods of modelling a curved surface in ray tracing computer models: an approximate method in which the surface is modelled as a series of planes, and an exact method which uses the precise analytical description of the surface. The focusing effects predicted using the two models in a hypothetical cylindrical space have been examined and compared. It was found that the approximate method of modelling the curved surface predicted focusing effects that were significantly different from those predicted using the exact method. However, the larger the number of planes used in the approximation, the closer the agreement between the two methods. The effects of source position and number of sources on focusing were also examined, and showed that focusing effects are stronger when the source position is on the axis of the cylinder. Propagation of sound across and along the cylinder has also been studied.

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19

Kroon-Batenburg, Loes M. J., Antoine M. M. Schreurs, Raimond B. G. Ravelli, and Piet Gros. "Accounting for partiality in serial crystallography using ray-tracing principles." Acta Crystallographica Section D Biological Crystallography 71, no. 9 (August 25, 2015): 1799–811. http://dx.doi.org/10.1107/s1399004715011803.

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Serial crystallography generates `still' diffraction data sets that are composed of single diffraction images obtained from a large number of crystals arbitrarily oriented in the X-ray beam. Estimation of the reflection partialities, which accounts for the expected observed fractions of diffraction intensities, has so far been problematic. In this paper, a method is derived for modelling the partialities by making use of the ray-tracing diffraction-integration methodEVAL. The method estimates partialities based on crystal mosaicity, beam divergence, wavelength dispersion, crystal size and the interference function, accounting for crystallite size. It is shown that modelling of each reflection by a distribution of interference-function weighted rays yields a `still' Lorentz factor. Still data are compared with a conventional rotation data set collected from a single lysozyme crystal. Overall, the presented still integration method improves the data quality markedly. TheRfactor of the still data compared with the rotation data decreases from 26% using a Monte Carlo approach to 12% after applying the Lorentz correction, to 5.3% when estimating partialities byEVALand finally to 4.7% after post-refinement. The mergingRintfactor of the still data improves from 105 to 56% but remains high. This suggests that the accuracy of the model parameters could be further improved. However, with a multiplicity of around 40 and anRintof ∼50% the merged still data approximate the quality of the rotation data. The presented integration method suitably accounts for the partiality of the observed intensities in still diffraction data, which is a critical step to improve data quality in serial crystallography.

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20

Oliva, G. André, and Francisco Frutos-Alfaro. "Effects of the treatment of the mass quadrupole moment on ray-tracing applications for rapidly rotating neutron stars." Monthly Notices of the Royal Astronomical Society 505, no. 2 (May 17, 2021): 2870–85. http://dx.doi.org/10.1093/mnras/stab1380.

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ABSTRACT The Neutron Star Interior Composition Explorer (NICER) mission has provided a unique opportunity to constrain the equation of state of neutron stars by using the technique of pulse-profile modelling. This technique requires accurate and efficient ray-tracing, that in turn requires a robust representation of the space–time around a neutron star. Several exact and approximate metrics have been proposed, and used, to perform ray-tracing around neutron stars, with both moderate and fast rotation. In this paper, we perform a comparison between several of these metrics, when used for ray-tracing. We calculate the shape of the neutron star as seen by a distant observer using two different surface formulae, the thermal spectrum and pulse profiles from circular and crescent-shaped hotspots, for four configurations of pulsars with rotation rates ranging from 622 to 1000 Hz, and using both a moderate and a stiff equation of state to include realistic and extreme cases. We find small differences between the metrics for rotation frequencies starting at ${\sim}700\, \mathrm{Hz}$ that could theoretically be used for constraining the quadrupole moment or the space–time models. We also determine the practicality of use of each metric in larger-scale applications such as pulse-profile modelling.

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21

Hesse, E. "Modelling diffraction during ray tracing using the concept of energy flow lines." Journal of Quantitative Spectroscopy and Radiative Transfer 109, no. 8 (May 2008): 1374–83. http://dx.doi.org/10.1016/j.jqsrt.2007.11.002.

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22

Pereira, José Carlos Garcia, José Rodríguez, Jorge Cruz Fernandes, and Luís Guerra Rosa. "Homogeneous Flux Distribution in High-Flux Solar Furnaces." Energies 13, no. 2 (January 16, 2020): 433. http://dx.doi.org/10.3390/en13020433.

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Comparisons between experimental data and ray-tracing simulation results are presented for the high-flux SF60 solar furnace available at the Plataforma Solar de Almeria, Spain, which has an estimated thermal power of 60 kW. Since an important issue in many applications of solar concentrated radiation is to obtain a radiation distribution that is as homogeneous as possible over the central working area, so-called radiation homogenisers were also used but the degree of success achieved is just satisfactory, as the results show. Finally, further modelling studies using ray-tracing simulations aiming to attain a homogenous distribution of flux by means of double reflexion using two paraboloid surfaces are presented.

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23

Novak, Roman. "Viability of Numerical Full-Wave Techniques in Telecommunication Channel Modelling." Journal of communications software and systems 16, no. 4 (October 8, 2020): 269–78. http://dx.doi.org/10.24138/jcomss.v16i4.1041.

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In telecommunication channel modelling the wavelength is small compared to the physical features of interest, therefore deterministic ray tracing techniques provide solutions that are more efficient, faster and still within time constraints than current numerical full-wave techniques. Solving fundamental Maxwell&apos;s equations is at the core of computational electrodynamics and best suited for modelling electrical field interactions with physical objects where characteristic dimensions of a computing domain is on the order of a few wavelengths in size. However, extreme communication speeds, wireless access points closer to the user and smaller pico and femto cells will require increased accuracy in predicting and planning wireless signals, testing the accuracy limits of the ray tracing methods. The increased computing capabilities and the demand for better characterization of communication channels that span smaller geographical areas make numerical full-wave techniques attractive alternative even for larger problems. The paper surveys ways of overcoming excessive time requirements of numerical full-wave techniques while providing acceptable channel modelling accuracy for the smallest radio cells and possibly wider. We identify several research paths that could lead to improved channel modelling, including numerical algorithm adaptations for large-scale problems, alternative finite-difference approaches, such as meshless methods, and dedicated parallel hardware, possibly as a realization of a dataflow machine.

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24

Ljungholm, Mikael, and Dan-E. Nilsson. "Modelling the visual world of a velvet worm." PLOS Computational Biology 17, no. 7 (July 28, 2021): e1008808. http://dx.doi.org/10.1371/journal.pcbi.1008808.

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In many animal phyla, eyes are small and provide only low-resolution vision for general orientation in the environment. Because these primitive eyes rarely have a defined image plane, traditional visual-optics principles cannot be applied. To assess the functional capacity of such eyes we have developed modelling principles based on ray tracing in 3D reconstructions of eye morphology, where refraction on the way to the photoreceptors and absorption in the photopigment are calculated incrementally for ray bundles from all angles within the visual field. From the ray tracing, we calculate the complete angular acceptance function of each photoreceptor in the eye, revealing the visual acuity for all parts of the visual field. We then use this information to generate visual filters that can be applied to high resolution images or videos to convert them to accurate representations of the spatial information seen by the animal. The method is here applied to the 0.1 mm eyes of the velvet worm Euperipatoides rowelli (Onychophora). These eyes of these terrestrial invertebrates consist of a curved cornea covering an irregular but optically homogeneous lens directly joining a retina packed with photoreceptive rhabdoms. 3D reconstruction from histological sections revealed an asymmetric eye, where the retina is deeper in the forward-pointing direction. The calculated visual acuity also reveals performance differences across the visual field, with a maximum acuity of about 0.11 cycles/deg in the forward direction despite laterally pointing eyes. The results agree with previous behavioural measurements of visual acuity, and suggest that velvet worm vision is adequate for orientation and positioning within the habitat.

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25

Oestges, C., S. R. Saunders, and D. Vanhoenacker-Janvier. "Physical statistical modelling of the land mobile satellite channel based on ray tracing." IEE Proceedings - Microwaves, Antennas and Propagation 146, no. 1 (1999): 45. http://dx.doi.org/10.1049/ip-map:19990144.

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26

Liu, Gang, Jun She, Wenjun Lu, Ming Zhang, and Yaming Bo. "3D deterministic ray tracing method for massive MIMO channel modelling and parameters extraction." IET Communications 14, no. 18 (November 17, 2020): 3169–74. http://dx.doi.org/10.1049/iet-com.2019.0884.

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27

Eester, D. Van, Y. Louis, and R. Koch. "Ray-tracing modelling of ICRH at arbitrary cyclotron harmonics in large hot plasmas." Plasma Physics and Controlled Fusion 35, no. 9 (September 1, 1993): 1189–206. http://dx.doi.org/10.1088/0741-3335/35/9/009.

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28

Houghton, C., C. Bloomer, and L. Alianelli. "Modelling the effects of optical vibrations on photon beam parameters using ray-tracing software." Journal of Synchrotron Radiation 28, no. 5 (August 12, 2021): 1357–63. http://dx.doi.org/10.1107/s1600577521007013.

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A method to simulate beam properties observed at the beamline sample-point in the presence of motion of optical components has been developed at Diamond Light Source. A series of stationary ray-tracing simulations are used to model the impact on the beam stability caused by dynamic motion of optical elements. Ray-tracing simulations using SHADOW3 in OASYS, completed over multiple iterations and stitched together, permit the modelling of a pseudo-dynamic beamline. As beamline detectors operating at higher frequencies become more common, beam stability is crucial. Synchrotron ring upgrades to low-emittance lattices require increased stability of beamlines in order to conserve beam brightness. By simulating the change in beam size and position, an estimate of the impact the motion of various components have on stability is possible. The results presented in this paper focus on modelling the physical vibration of optical elements. Multiple beam parameters can be analysed in succession without manual input. The simulation code is described and the initial results obtained are presented. This method can be applied during beamline design and operation for the identification of optical elements that may introduce large errors in the beam properties at the sample-point.

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29

Consani, Cristina, Norbert Druml, Markus Dielacher, and Marcus Baumgart. "Fog Effects on Time-of-Flight Imaging Investigated by Ray-Tracing Simulations." Proceedings 2, no. 13 (November 29, 2018): 859. http://dx.doi.org/10.3390/proceedings2130859.

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Time-of-Flight (ToF) sensors are a key technology for autonomous vehicles and autonomous mobile robotics. Quantifying the extent of perturbation induced by atmospheric phenomena on ToF imaging is critical to identify effective correction strategies. Here we present an approach that uses optical ray-tracing to simulate the ToF image, while the distance information is recovered by analyzing the optical path of each ray. Such an approach allows, for example, understanding the effects of different ray paths on the ToF image, or testing various retrieval/correction algorithms upon running a single ray-tracing simulation. By modelling several scattering scenarios, we show that ranging errors arise mostly from light backscattered to the sensor prior reaching the scene. Scattering events close to the sensors (<1 m) have the largest influence, therefore strategies capable of filtering out signals from distances shorter than the range of interest can significantly improve the accuracy of ToF sensors.

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30

Lin, Psang Dain, and Chuang-Yu Tsai. "Skew ray tracing and sensitivity analysis of ellipsoidal optical boundary surfaces." Applied Mathematical Modelling 32, no. 12 (December 2008): 2526–37. http://dx.doi.org/10.1016/j.apm.2007.09.022.

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31

Näränen, Jyri, Hannu Parviainen, and Karri Muinonen. "X-ray fluorescence modelling for Solar system regoliths: Effects of viewing geometry, particle size, and surface roughness." Proceedings of the International Astronomical Union 2, S236 (August 2006): 243–50. http://dx.doi.org/10.1017/s1743921307003298.

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AbstractSoft X-ray fluorescent emission from the surfaces of asteroids and other atmosphereless solar-system objects is studied using ray-tracing techniques. X-ray observations allow the assessment of the elemental composition and structure of the surface. The model regolith is assumed to consist of close-packed uniformly distributed spherical particles of equal size. The surface is also assumed to be rough according to a fractional-Brownian-motion model. The fluorescent X-ray emission from regolith surfaces is simulated in order to better understand the contribution of viewing-geometry -related phenomena on the signal obtained from, e.g., orbiting platforms. The first results are presented and the applicability of the methods to the interpretation of future asteroid and Mercury mission X-ray data (e.g., BepiColombo) is discussed.

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32

Asif, H. M., B. Honary, and H. Ahmed. "Multiple-input multiple-output ultra-wide band channel modelling method based on ray tracing." IET Communications 6, no. 10 (2012): 1195. http://dx.doi.org/10.1049/iet-com.2011.0265.

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33

Adnan, Farasatul, Valon Blakaj, Sendy Phang, Thomas M. Antonsen, Stephen C. Creagh, Gabriele Gradoni, and Gregor Tanner. "Wireless power distributions in multi-cavity systems at high frequencies." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 477, no. 2245 (January 2021): 20200228. http://dx.doi.org/10.1098/rspa.2020.0228.

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The next generations of wireless networks will work in frequency bands ranging from sub-6 GHz up to 100 GHz. Radio signal propagation differs here in several critical aspects from the behaviour in the microwave frequencies currently used. With wavelengths in the millimetre range (mmWave), both penetration loss and free-space path loss increase, while specular reflection will dominate over diffraction as an important propagation channel. Thus, current channel model protocols used for the generation of mobile networks and based on statistical parameter distributions obtained from measurements become insufficient due to the lack of deterministic information about the surroundings of the base station and the receiver-devices. These challenges call for new modelling tools for channel modelling which work in the short-wavelength/high-frequency limit and incorporate site-specific details—both indoors and outdoors. Typical high-frequency tools used in this context—besides purely statistical approaches—are based on ray-tracing techniques. Ray-tracing can become challenging when multiple reflections dominate. In this context, mesh-based energy flow methods have become popular in recent years. In this study, we compare the two approaches both in terms of accuracy and efficiency and benchmark them against traditional power balance methods.

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34

Othman, Shah Farez, Nizam Tamchek, Farah Diana Muhammad, and Mohd Hafidz Ithnin. "Modulation Transfer Function Analysis in Myopic Model Eye." ASM Science Journal 16 (July 15, 2021): 1–8. http://dx.doi.org/10.32802/asmscj.2021.688.

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Hitherto, the eye modelling is based on the emmetropic eye taken its ocular optical components value from the population-based studies. However, no studies have been done to study the effect of aberration of myopic refractive error by modelling the eye using the parameters from ocular biometrics and ray tracing method. This study aimed to determine the modulation transfer function (MTF) of myopic refractive error using eye modelling and ray tracing technique. Three eye models had been successfully modelled in Zemax software, namely, emmetropic Liou and Brennan, myopic Liou and Brennan, corrected myopic Liou and Brennan. The optical performance of the eye models were tested using the MTF. From the MTF analysis at 100 cycles/mm, the MTF value of both tangential and sagittal rays for myopic Liou and Brennan eye was the lowest compared to its emmetropic model. Also, the MTF value of the corrected myopic Liou and Brennan model was higher compared to the uncorrected myopic model. However, the corrected myopic model produced lower MTF values for both tangential and sagittal MTF compared with the emmetropic model of Liou and Brennan. In this study, the accuracy of the MTF for myopia correction and emmetropia were calculated. It was found that the accuracy of the MTF value for corrected myopia at tangential and sagittal rays was lower.

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35

Wu, Feng, Xifang Zhu, Ruxi Xiang, Xiaoyan Jiang, Qingquan Xu, Gong Chen, and Tao Wu. "Image Simulation for 3-FOV Daytime Star Sensor Based on Ray Tracing." Advances in Modelling and Analysis B 60, no. 2 (June 30, 2017): 493–504. http://dx.doi.org/10.18280/ama_b.600216.

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36

Lièbe, Christophe, Pierre Combeau, Alain Gaugue, Yannis Pousset, Lilian Aveneau, Rodolphe Vauzelle, and Jean-Marc Ogier. "Ultra-Wideband Indoor Channel Modelling Using Ray-Tracing Software for through-the-Wall Imaging Radar." International Journal of Antennas and Propagation 2010 (2010): 1–14. http://dx.doi.org/10.1155/2010/934602.

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This paper presents a new software for design of through-the-wall imaging radars. The first part describes the evolution of a ray tracing simulator, originally designed for propagation of narrowband signals, and then for ultra-wideband signals. This simulator allows to obtain temporal channel response to a wide-band emitter (3 GHz to 10 GHz). An experimental method is also described to identify the propagation paths. Simulation results are compared to propagation experiments under the same conditions. Different configurations are tested and then discussed. Finally, a configuration of through-the-wall imaging radar is proposed, with different antennas patterns and different targets. Simulated images will be helpful for understanding the experiment obtained images.

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37

Mohtashami, V., and A. A. Shishegar. "Efficient ultrawideband propagation modelling by using the cubic B-spline function in ray tracing calculations." IET Microwaves, Antennas & Propagation 6, no. 12 (2012): 1347. http://dx.doi.org/10.1049/iet-map.2012.0306.

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38

Lau, Lawrence, and Paul Cross. "Development and testing of a new ray-tracing approach to GNSS carrier-phase multipath modelling." Journal of Geodesy 81, no. 11 (March 13, 2007): 713–32. http://dx.doi.org/10.1007/s00190-007-0139-z.

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39

Winkler-Skalna, Agnieszka, and Artur Nowoświat. "Use of n-perturbation interval ray tracing method in predicting acoustic field distribution." Applied Mathematical Modelling 93 (May 2021): 426–42. http://dx.doi.org/10.1016/j.apm.2020.12.028.

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40

Previtali, Mattia, Lucía Díaz-Vilariño, and Marco Scaioni. "Indoor Building Reconstruction from Occluded Point Clouds Using Graph-Cut and Ray-Tracing." Applied Sciences 8, no. 9 (September 1, 2018): 1529. http://dx.doi.org/10.3390/app8091529.

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Despite the increasing demand of updated and detailed indoor models, indoor reconstruction from point clouds is still in an early stage in comparison with the reconstruction of outdoor scenes. Specific challenges are related to the complex building layouts and the high presence of elements such as pieces of furniture causing clutter and occlusions. This work proposes an automatic method for modelling Manhattan-World indoors acquired with a mobile laser scanner in the presence of highly occluded walls. The core of the methodology is the transformation of indoor reconstruction into a labelling problem of structural cells in a 2D floor plan. Assuming the prevalence of orthogonal intersections between walls, indoor completion is formulated as an energy minimization problem using graph cuts. Doors and windows are detected from occlusions by implementing a ray-tracing algorithm. The methodology is tested in a real case study. Except for one window partially covered by a curtain, all building elements were successfully reconstructed.

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41

Sylta, Øyvind. "Modelling of secondary migration and entrapment of a multicomponent hydrocarbon mixture using equation of state and ray-tracing modelling techniques." Geological Society, London, Special Publications 59, no. 1 (1991): 111–22. http://dx.doi.org/10.1144/gsl.sp.1991.059.01.07.

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42

Blagoveshchensky, D. V., K. A. Dobroselsky, and O. A. Maltseva. "Guiding MF waves from the Earth's surface into space." Annales Geophysicae 15, no. 2 (February 28, 1997): 246–48. http://dx.doi.org/10.1007/s00585-997-0246-4.

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Abstract. The insufficiently known phenomenon of MF- wave propagation from the Earth's surface through the magnetosphere (guiding) to the conjugate hemisphere and back to the transmitter has been experimentally studied. Computer modelling fulfilled on the basis of ray tracing showed that guiding was possible only from area of the main ionospheric trough. The effect of MF guiding is most useful for the diagnostics of the plasmapause, poleward edge of the trough, the diffuse precipitation boundary and so on.

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43

Masson, O., R. Guinebretiere, and A. Dauger. "Modelling of line profile asymmetry caused by axial divergence in powder diffraction." Journal of Applied Crystallography 34, no. 4 (July 22, 2001): 436–41. http://dx.doi.org/10.1107/s0021889801005428.

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A procedure is presented for modelling the axial divergence aberration profile, taking into account all second-order and end effects of the diffractometer system. It is shown that relatively simple calculations, which could be introduced into Rietveld refinement programs, allow the instrument line profile to be modelled accurately at low and high scattering angles. This model compares well with ray-tracing calculations and can give better results than the usually used model proposed by Van Laar & Yelon [J. Appl. Cryst.(1984),17, 47–54] and Finger, Cox & Jephcoat [J. Appl. Cryst.(1994),27, 892–900].

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44

Scott, T. D., V. F. Fusco, and R. S. Ferguson. "Multi-threaded 3D ray tracing on PC networks using TCP/IP." International Journal of Numerical Modelling: Electronic Networks, Devices and Fields 13, no. 6 (2000): 511–25. http://dx.doi.org/10.1002/1099-1204(200011/12)13:6<511::aid-jnm390>3.0.co;2-g.

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45

Bailey, Brian N. "A reverse ray-tracing method for modelling the net radiative flux in leaf-resolving plant canopy simulations." Ecological Modelling 368 (January 2018): 233–45. http://dx.doi.org/10.1016/j.ecolmodel.2017.11.022.

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46

Kamboh, Usman Rauf, Ubaid Ullah, Shehzad Khalid, Umar Raza, Chinmay Chakraborty, and Fadi Al-Turjman. "Path loss modelling at 60 GHz mmWave based on cognitive 3D ray tracing algorithm in 5G." Peer-to-Peer Networking and Applications 14, no. 5 (March 11, 2021): 3181–97. http://dx.doi.org/10.1007/s12083-021-01101-w.

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47

Deep, Yoshana, Patrick Held, Shobha Sundar Ram, Dagmar Steinhauser, Anshu Gupta, Frank Gruson, Andreas Koch, and Anirban Roy. "Radar cross‐sections of pedestrians at automotive radar frequencies using ray tracing and point scatterer modelling." IET Radar, Sonar & Navigation 14, no. 6 (April 28, 2020): 833–44. http://dx.doi.org/10.1049/iet-rsn.2019.0471.

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48

Guerra, V., C. Quintana, J. Rufo, J. Rabadan, and R. Perez-Jimenez. "Parallelization of a Monte Carlo Ray Tracing Algorithm for Channel Modelling in Underwater Wireless Optical Communications." Procedia Technology 7 (2013): 11–19. http://dx.doi.org/10.1016/j.protcy.2013.04.002.

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49

Klinkrad, H., Ch Koeck, and P. Renard. "Key features of a satellite skin force modelling technique by means of Monte-Carlo ray tracing." Advances in Space Research 11, no. 6 (January 1991): 147–50. http://dx.doi.org/10.1016/0273-1177(91)90244-e.

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50

Ranguelov, Boyko, and Dragomir Gospodinov. "Tsunami vulnerability modelling for the Bulgarian Black Sea coast." Water Science and Technology 32, no. 7 (October 1, 1995): 47–53. http://dx.doi.org/10.2166/wst.1995.0198.

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The problem of tsunami hazard assessment and water pollution appear during the last years in connection with the increased density of infrastructure and industrial facilities on the Black Sea coast. The paper deals with the main results of the tsunami vulnerability modelling in accordance with the internationally recognised methods and new data obtained during the last years. Data collection, new approaches for travel times and dynamic properties of the giant sea waves have been investigated in the previous research. Now the main tsunamigenic sources together with the most vulnerable areas are outlined on the Bulgarian part of the coast. Together with the tsunami energy distribution according to the new method of ray tracing and refraction, the results give the possibility to establish the concentration-dissipation areas, which are most important to the tsunami risk assessment.

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