Pub Date : 2025-01-10DOI: 10.1016/j.jqsrt.2025.109346
M. Ganesh , Stuart C. Hawkins
Using extensive numerical computations for several benchmark geometries, we demonstrate the physical correctness and numerical stability of a two-step algorithm for computing the electromagnetic-scattering T-matrix of homogeneous penetrable three-dimensional scatterers with smooth boundaries. Our numerical results show that the T-matrices computed with our algorithm have high accuracy, even at size parameters and aspect ratios exceeding the upper limits that can be tackled using the current state-of-the-art algorithm, the Extended Boundary Condition Method. The two-step algorithm is an extension to penetrable scatterers of the algorithm introduced in Ganesh and Hawkins (2010) for perfect conductors. The numerical stability of the T-matrix algorithm stems from the application of an efficient new high-order method in the first step, and a stable fully-discrete Laplace–Fourier transform in the second step. The high-order method is based on a recently established surface integral equation formulation for electromagnetic scattering by bounded penetrable media, for which stability at all-frequencies has been proven.
{"title":"T-matrix computations for light scattering by penetrable particles with large aspect ratios","authors":"M. Ganesh , Stuart C. Hawkins","doi":"10.1016/j.jqsrt.2025.109346","DOIUrl":"10.1016/j.jqsrt.2025.109346","url":null,"abstract":"<div><div>Using extensive numerical computations for several benchmark geometries, we demonstrate the physical correctness and numerical stability of a two-step algorithm for computing the electromagnetic-scattering T-matrix of homogeneous penetrable three-dimensional scatterers with smooth boundaries. Our numerical results show that the T-matrices computed with our algorithm have high accuracy, even at size parameters and aspect ratios exceeding the upper limits that can be tackled using the current state-of-the-art algorithm, the Extended Boundary Condition Method. The two-step algorithm is an extension to penetrable scatterers of the algorithm introduced in Ganesh and Hawkins (2010) for perfect conductors. The numerical stability of the T-matrix algorithm stems from the application of an efficient new high-order method in the first step, and a stable fully-discrete Laplace–Fourier transform in the second step. The high-order method is based on a recently established surface integral equation formulation for electromagnetic scattering by bounded penetrable media, for which stability at all-frequencies has been proven.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"334 ","pages":"Article 109346"},"PeriodicalIF":2.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-09DOI: 10.1016/j.jqsrt.2025.109339
Xiaozhi Shen , Juan Liu , Chenming Wang , Huaying Wang , Zhanbin Chen , Yan Sun
Based on the multiconfiguration Dirac–Hartree–Fock (MCDHF) method, accurate atomic spectra data including the transition rates, line strengths, and oscillator strengths for the inner-shell excited configuration 2s2p (P)3p in N II ion are reported by taking into account the core-core, core-valence and valence correlation effects as well as the Breit interaction. Good accordance can be found in the comparison with other calculations and measurements. Meanwhile, by studying the effects of electron correlations on the energy levels and transition rates of 2s2p (P)3p configuration, it is found that the valence correlations of active space = { = 2–7, = s–i} and the core correlations with regard to 1 electrons have the strongly adjusted effect and the balancing influence, respectively. Furthermore, the quintet transitions 2s2p (P)3s P–2s2p (P)3p L (L = P, D) are found to strictly obey the selection rule S = 0. The branching fractions under this case tend to 1, which is a peculiarly intrinsic property that is recommended to diagnose the lifetimes or rates of quintet states.
{"title":"Transition rates and electron correlation effects for the 2s2p2 (4P)3p configuration in N II","authors":"Xiaozhi Shen , Juan Liu , Chenming Wang , Huaying Wang , Zhanbin Chen , Yan Sun","doi":"10.1016/j.jqsrt.2025.109339","DOIUrl":"10.1016/j.jqsrt.2025.109339","url":null,"abstract":"<div><div>Based on the multiconfiguration Dirac–Hartree–Fock (MCDHF) method, accurate atomic spectra data including the transition rates, line strengths, and oscillator strengths for the inner-shell excited configuration 2s2p<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> (<span><math><msup><mrow></mrow><mrow><mn>4</mn></mrow></msup></math></span>P)3p in N II ion are reported by taking into account the core-core, core-valence and valence correlation effects as well as the Breit interaction. Good accordance can be found in the comparison with other calculations and measurements. Meanwhile, by studying the effects of electron correlations on the energy levels and transition rates of 2s2p<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> (<span><math><msup><mrow></mrow><mrow><mn>4</mn></mrow></msup></math></span>P)3p configuration, it is found that the valence correlations of active space <span><math><mrow><mi>n</mi><mi>l</mi></mrow></math></span> = {<span><math><mi>n</mi></math></span> = 2–7, <span><math><mi>l</mi></math></span> = s–i} and the core correlations with regard to 1<span><math><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> electrons have the strongly adjusted effect and the balancing influence, respectively. Furthermore, the quintet transitions 2s2p<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> (<span><math><msup><mrow></mrow><mrow><mn>4</mn></mrow></msup></math></span>P)3s <span><math><msup><mrow></mrow><mrow><mn>5</mn></mrow></msup></math></span>P–2s2p<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> (<span><math><msup><mrow></mrow><mrow><mn>4</mn></mrow></msup></math></span>P)3p <span><math><msup><mrow></mrow><mrow><mn>5</mn></mrow></msup></math></span>L<span><math><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span> (L = P, D) are found to strictly obey the selection rule <span><math><mi>Δ</mi></math></span>S = 0. The branching fractions under this case tend to 1, which is a peculiarly intrinsic property that is recommended to diagnose the lifetimes or rates of quintet states.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"334 ","pages":"Article 109339"},"PeriodicalIF":2.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-09DOI: 10.1016/j.jqsrt.2025.109348
A.P. Chaynikov, A.G. Kochur, A.I. Dudenko
Emission of electrons and photons during the cascade decay of inner-shell vacancies created after the decay of unstable 125I radionuclide is simulated by construction and analysis of the cascade decay trees in isolated-ion approximation. The yields of final cascade ions, the number of emitted electrons and photons, and their spectra, are calculated. During one transformation of 125I, the total energy emitted to the environment is 61.7 keV, of which 43.3 keV is emitted by photons, mostly high-energy KL photons produced at the first step of the decays of the 1s vacancies. If 125I is used as an agent for Auger therapy of cancer, only the energy absorbed by the tumor tissues in the nearest vicinity of the emitter is important. This energy is 18.6 keV, most of which is provided by cascade-produced electrons. The contribution of low-energy photons and cascade-produced ions to local energy deposition are 0.15 keV and 0.7 keV, respectively. Additional monopole ejection of electrons (shake off) during the cascades progression, and upon the internal conversion of 125Te* nuclide produced by the electron capture decay of 125I, is shown to affect little the final ions charges and emitted energies.
{"title":"Emission of electrons and photons and formation of cascade ions during the decay of 125I radionuclide","authors":"A.P. Chaynikov, A.G. Kochur, A.I. Dudenko","doi":"10.1016/j.jqsrt.2025.109348","DOIUrl":"10.1016/j.jqsrt.2025.109348","url":null,"abstract":"<div><div>Emission of electrons and photons during the cascade decay of inner-shell vacancies created after the decay of unstable <sup>125</sup>I radionuclide is simulated by construction and analysis of the cascade decay trees in isolated-ion approximation. The yields of final cascade ions, the number of emitted electrons and photons, and their spectra, are calculated. During one transformation of <sup>125</sup>I, the total energy emitted to the environment is 61.7 keV, of which 43.3 keV is emitted by photons, mostly high-energy <em>KL</em> photons produced at the first step of the decays of the 1<em>s</em> vacancies. If <sup>125</sup>I is used as an agent for Auger therapy of cancer, only the energy absorbed by the tumor tissues in the nearest vicinity of the emitter is important. This energy is 18.6 keV, most of which is provided by cascade-produced electrons. The contribution of low-energy photons and cascade-produced ions to local energy deposition are 0.15 keV and 0.7 keV, respectively. Additional monopole ejection of electrons (shake off) during the cascades progression, and upon the internal conversion of <sup>125</sup>Te* nuclide produced by the electron capture decay of <sup>125</sup>I, is shown to affect little the final ions charges and emitted energies.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"334 ","pages":"Article 109348"},"PeriodicalIF":2.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The work proposes a two-step indirect method for evaluating the beam shape coefficients (BSCs) of the electromagnetic (EM) field of shaped beams. The spherical wave expansion of the EM field is based on the expansion of the scalar potential function so that the BSCs of the EM field are obtained as the linear combinations of the BSCs of the potential function. By using the scalar translational addition theorem, the BSCs of the potential function in the particle coordinate system are obtained from those in the beam system. The beams having circular profile and carrying no topological charge are considered in the work. The method simplifies the formulation of the BSCs and speeds up the numerical calculations. The numerical results for the Gaussian beam validate the method in evaluating the BSCs and reproducing the beam field in both accuracy and efficiency.
{"title":"Speed up the beam shape coefficient evaluation by using scalar spherical wave expansion and scalar translational addition theorem","authors":"Jianqi Shen , Yu Wang , Shiliang Zhong , Yiqian Tian , Haoyu Jiang","doi":"10.1016/j.jqsrt.2025.109343","DOIUrl":"10.1016/j.jqsrt.2025.109343","url":null,"abstract":"<div><div>The work proposes a two-step indirect method for evaluating the beam shape coefficients (BSCs) of the electromagnetic (EM) field of shaped beams. The spherical wave expansion of the EM field is based on the expansion of the scalar potential function so that the BSCs of the EM field are obtained as the linear combinations of the BSCs of the potential function. By using the scalar translational addition theorem, the BSCs of the potential function in the particle coordinate system are obtained from those in the beam system. The beams having circular profile and carrying no topological charge are considered in the work. The method simplifies the formulation of the BSCs and speeds up the numerical calculations. The numerical results for the Gaussian beam validate the method in evaluating the BSCs and reproducing the beam field in both accuracy and efficiency.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"334 ","pages":"Article 109343"},"PeriodicalIF":2.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-08DOI: 10.1016/j.jqsrt.2025.109342
Afshin Moradi , Mohammed M. Bait-Suwailam
The present work explores the application of microwave remote sensing to distinguish between healthy and infested date palm trees, using a novel approach centered around the scattering to absorption width ratio (SAWR). Through comprehensive analytical formulations and numerical modeling, we investigate the interaction of palm trees with microwaves at oblique incidence, specifically at a frequency of 2.45 GHz (ISM-band). The study examines the behavior of TE and TM polarizations waves (relative to the -axis), providing detailed analyses of their scattering and absorption characteristics as functions of incident angles. Our findings demonstrate that the SAWR metric is a promising indicator for assessing palm tree health, effectively differentiating between healthy and pest-infested trees. This research offers a non-destructive, real-time method for monitoring tree health, with significant implications for pest detection in agricultural practices.
{"title":"A new theoretical method for remotely assessing the health of date palm trees using the scattering/absorption ratio of obliquely incident electromagnetic waves","authors":"Afshin Moradi , Mohammed M. Bait-Suwailam","doi":"10.1016/j.jqsrt.2025.109342","DOIUrl":"10.1016/j.jqsrt.2025.109342","url":null,"abstract":"<div><div>The present work explores the application of microwave remote sensing to distinguish between healthy and infested date palm trees, using a novel approach centered around the scattering to absorption width ratio (SAWR). Through comprehensive analytical formulations and numerical modeling, we investigate the interaction of palm trees with microwaves at oblique incidence, specifically at a frequency of 2.45 GHz (ISM-band). The study examines the behavior of TE<span><math><msup><mrow></mrow><mrow><mi>z</mi></mrow></msup></math></span> and TM<span><math><msup><mrow></mrow><mrow><mi>z</mi></mrow></msup></math></span> polarizations waves (relative to the <span><math><mi>z</mi></math></span>-axis), providing detailed analyses of their scattering and absorption characteristics as functions of incident angles. Our findings demonstrate that the SAWR metric is a promising indicator for assessing palm tree health, effectively differentiating between healthy and pest-infested trees. This research offers a non-destructive, real-time method for monitoring tree health, with significant implications for pest detection in agricultural practices.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"333 ","pages":"Article 109342"},"PeriodicalIF":2.3,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-04DOI: 10.1016/j.jqsrt.2025.109340
Huiling Liu, Xingxing Han, Bei Zhao, Jing Shi, Le Zhu
To analyze the influence of eccentricity and the properties of a focused beam on the features of photonic jets (PJs) formed by an eccentrically coated sphere, light scattering of an eccentrically coated sphere illuminated by a focused Gaussian beam is investigated by using the generalized Lorenz-Mie theory. Variations of internal and near-surface field distributions are calculated with the change of the core locations inside of the particle. Numerical results concerning the behaviors of PJs, including the position of maximum intensity, focal distance, value of peak intensity, and transversal dimension of PJ expressed by full width half maximum (FWHM), are presented. The results show that by properly tuning the location of core, the PJ parameters can be efficiently engineered. The PJs can also be further adjusted by varying the beam waist radius of the incident Gaussian beam, which provide an extra way to adjust the PJ patterns for a particle with fixed structure.
{"title":"Characteristics of photonic jet formed by an eccentrically coated dielectric sphere","authors":"Huiling Liu, Xingxing Han, Bei Zhao, Jing Shi, Le Zhu","doi":"10.1016/j.jqsrt.2025.109340","DOIUrl":"10.1016/j.jqsrt.2025.109340","url":null,"abstract":"<div><div>To analyze the influence of eccentricity and the properties of a focused beam on the features of photonic jets (PJs) formed by an eccentrically coated sphere, light scattering of an eccentrically coated sphere illuminated by a focused Gaussian beam is investigated by using the generalized Lorenz-Mie theory. Variations of internal and near-surface field distributions are calculated with the change of the core locations inside of the particle. Numerical results concerning the behaviors of PJs, including the position of maximum intensity, focal distance, value of peak intensity, and transversal dimension of PJ expressed by full width half maximum (FWHM), are presented. The results show that by properly tuning the location of core, the PJ parameters can be efficiently engineered. The PJs can also be further adjusted by varying the beam waist radius of the incident Gaussian beam, which provide an extra way to adjust the PJ patterns for a particle with fixed structure.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"334 ","pages":"Article 109340"},"PeriodicalIF":2.3,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-03DOI: 10.1016/j.jqsrt.2025.109341
Chen Zhou , He Huang , Lei Bi
Geometric optics methods with intensity mapping have been widely used to calculate the single-scattering properties of randomly oriented non-spherical particles with large size parameters, but the backscattering phase functions are often underestimated. The primary reason is that the coherent backscatter enhancement (CBE) is not addressed when the intensity mapping technique is used. In this paper, the phase difference between each pair of conjugate reversible rays is computed in the ray-tracing module of the improved geometric optics method (IGOM), and the effect of CBE is incorporated by considering the interference between conjugate rays. The phase functions of regular hexagons, roughened hexagons, and spheroids with different size parameters and refractive indices are simulated using both the original IGOM and the IGOM with CBE considered (IGOM-CBE), and the results are compared to rigorous numerical simulations that solve Maxwell's equations. The results show that the near-backscattering phase functions calculated with the IGOM-CBE are more consistent with rigorous numerical simulations for all cases, indicating that the paired ray-tracing process effectively improves the backscatter simulated by the geometric optics method.
{"title":"Simulation of backscattering phase function with the geometric optics method using a paired ray-tracing technique","authors":"Chen Zhou , He Huang , Lei Bi","doi":"10.1016/j.jqsrt.2025.109341","DOIUrl":"10.1016/j.jqsrt.2025.109341","url":null,"abstract":"<div><div>Geometric optics methods with intensity mapping have been widely used to calculate the single-scattering properties of randomly oriented non-spherical particles with large size parameters, but the backscattering phase functions are often underestimated. The primary reason is that the coherent backscatter enhancement (CBE) is not addressed when the intensity mapping technique is used. In this paper, the phase difference between each pair of conjugate reversible rays is computed in the ray-tracing module of the improved geometric optics method (IGOM), and the effect of CBE is incorporated by considering the interference between conjugate rays. The phase functions of regular hexagons, roughened hexagons, and spheroids with different size parameters and refractive indices are simulated using both the original IGOM and the IGOM with CBE considered (IGOM-CBE), and the results are compared to rigorous numerical simulations that solve Maxwell's equations. The results show that the near-backscattering phase functions calculated with the IGOM-CBE are more consistent with rigorous numerical simulations for all cases, indicating that the paired ray-tracing process effectively improves the backscatter simulated by the geometric optics method.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"334 ","pages":"Article 109341"},"PeriodicalIF":2.3,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-02DOI: 10.1016/j.jqsrt.2024.109338
Luka Rajačić, Nikodin V. Nedić, Dejan Dojić, Miloš Skočić, Srdjan Bukvić
In this paper, we discuss the technical and numerical aspects related to a specific diagnostic tool, the Saha–Boltzmann plot, introduced in plasma spectroscopy by Yalcin et al. in 1999. The method has a clear physical background and requires only common spectroscopic data as input parameters. The output parameters are the electron temperature and the electron density of the investigated plasma. In this paper, we explain how to correctly estimate the uncertainties of electron temperature and electron density, regardless of whether the accuracy of the input parameters is known or not. In addition, we offer a computer program, as part of a free web service, that efficiently solves the ’Saha–Boltzmann plot’ task.
{"title":"Saha–Boltzmann method in plasma diagnostics: What can we obtain from a strict approach?","authors":"Luka Rajačić, Nikodin V. Nedić, Dejan Dojić, Miloš Skočić, Srdjan Bukvić","doi":"10.1016/j.jqsrt.2024.109338","DOIUrl":"10.1016/j.jqsrt.2024.109338","url":null,"abstract":"<div><div>In this paper, we discuss the technical and numerical aspects related to a specific diagnostic tool, the Saha–Boltzmann plot, introduced in plasma spectroscopy by Yalcin et al. in 1999. The method has a clear physical background and requires only common spectroscopic data as input parameters. The output parameters are the electron temperature and the electron density of the investigated plasma. In this paper, we explain how to correctly estimate the uncertainties of electron temperature and electron density, regardless of whether the accuracy of the input parameters is known or not. In addition, we offer a computer program, as part of a free web service, that efficiently solves the ’Saha–Boltzmann plot’ task.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"333 ","pages":"Article 109338"},"PeriodicalIF":2.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.jqsrt.2024.109329
Gérard Gouesbet , Leonardo A. Ambrosio , Jianqi Shen
On one hand, we consider two T-matrix theories, namely “Generalized Lorenz–Mie theory” (GLMT) and “Extended Boundary Condition Method” (EBCM), in which structured beams may be expanded over Vector Spherical Wave Functions (VSWFs), with expansion coefficients expressed by using electromagnetic Beam Shape Coefficients (BSCs). On the other hand, we consider acoustical (more generally scalar) fields which may be expressed similarly by an expansion over basic functions, with expansion coefficients expressed using acoustical (scalar) BSCs. We establish relationships between electromagnetic and scalar BSCs.
{"title":"On a relationship between acoustical (more generally scalar) beam shape coefficients and electromagnetic beam shape coefficients of some T-matrix theories for structured beams","authors":"Gérard Gouesbet , Leonardo A. Ambrosio , Jianqi Shen","doi":"10.1016/j.jqsrt.2024.109329","DOIUrl":"10.1016/j.jqsrt.2024.109329","url":null,"abstract":"<div><div>On one hand, we consider two T-matrix theories, namely “Generalized Lorenz–Mie theory” (GLMT) and “Extended Boundary Condition Method” (EBCM), in which structured beams may be expanded over Vector Spherical Wave Functions (VSWFs), with expansion coefficients expressed by using electromagnetic Beam Shape Coefficients (BSCs). On the other hand, we consider acoustical (more generally scalar) fields which may be expressed similarly by an expansion over basic functions, with expansion coefficients expressed using acoustical (scalar) BSCs. We establish relationships between electromagnetic and scalar BSCs.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"333 ","pages":"Article 109329"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142929285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-30DOI: 10.1016/j.jqsrt.2024.109336
Zhao-Cheng Zeng
This study presents an information content analysis of the retrieval of global carbon monoxide (CO) from the 2nd generation of Hyperspectral Infrared Atmospheric Sounder on board Fengyun-3E (FY-3E/HIRAS-II), which is the world's first dawn-dusk orbiting meteorological satellite for civilian use with equatorial overpass times at about 5:30am/pm. Using the distinctive absorption features of CO around 2145 cm-1 in the infrared band, a retrieval algorithm based on optimal estimation is first developed to retrieve the CO profiles from FY-3E/HIRAS-II. The thermal contrast, defined as the temperature difference between the surface and the lower atmosphere, is then examined for the FY-3E/HIRAS-II observations to investigate the potential sensitivity of the observations. Retrievals of CO columns on four representative days over four seasons reveal strong enhancements from global wildfire emissions. Furthermore, the information content from the spectra, quantified by the degree of freedom for signal (DOFS), is assessed using the retrievals. The retrievals are compared with model simulations, which show good agreement. Finally, synthetic experiments are performed to investigate the impacts of thermal contrast and the vertical structure of wildfire-induced CO enhancement on the observational sensitivity. The result highlights the effectiveness of observing wildfire-induced CO enhancement during the dawn and dusk hours, even when thermal contrast conditions are not favorable. This study demonstrates the capability of FY-3E/HIRAS-II to monitor global CO, which sheds light on the potential benefits of adding dawn-dusk orbit observations to the current global air quality observations from mid-morning and early-afternoon orbit constellations.
本文对全球首颗民用黎明-黄昏轨道气象卫星风云- 3e （FY-3E/HIRAS-II）搭载的第二代高光谱红外大气探测仪（hras - ii）全球一氧化碳（CO）数据进行了信息含量分析。风云- 3e /HIRAS-II是全球首颗民用黎明-黄昏轨道气象卫星，赤道上空时间为上午/下午5:30左右。利用红外波段CO在2145 cm-1附近的独特吸收特征，提出了一种基于最优估计的检索算法，用于检索FY-3E/HIRAS-II的CO剖面。热对比，定义为地表和低层大气之间的温差，然后为FY-3E/HIRAS-II观测进行检查，以研究观测的潜在灵敏度。四个季节中四个代表性日的CO柱检索显示全球野火排放的强烈增强。此外，通过信号的自由度（DOFS）来量化光谱的信息含量，并利用检索结果进行评估。将反演结果与模型模拟结果进行了比较，结果吻合较好。最后，通过综合实验研究了热对比和野火诱导CO增强的垂直结构对观测灵敏度的影响。结果强调了在黎明和黄昏观测野火引起的CO增强的有效性，即使在热对比条件不利的情况下也是如此。这项研究证明了FY-3E/HIRAS-II监测全球CO的能力，这揭示了将黎明-黄昏轨道观测增加到目前从上午中期和下午早期轨道星座进行的全球空气质量观测的潜在好处。
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