Radio Science最新文献

Competitive metaheuristic algorithms for building a performance database of a dual-band combline bandpass filter with microstrip connection 基于竞争元启发式算法的双带组合带通滤波器性能数据库构建

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1029/2024RS008142

Ahmet Uluslu;Kervendurdy Allaberdiyev

{"title":"Competitive metaheuristic algorithms for building a performance database of a dual-band combline bandpass filter with microstrip connection","authors":"Ahmet Uluslu;Kervendurdy Allaberdiyev","doi":"10.1029/2024RS008142","DOIUrl":"https://doi.org/10.1029/2024RS008142","url":null,"abstract":"Dual-band bandpass filters have attracted intense attention in recent developments to meet many demands, especially wireless applications and multi-band radio wave. Here, a Combline filter in the form of a dual bandpass 3-row microstrip with a center resonance frequency of 2.5 and 3.0 GHz and a total of 13 design parameters, 6 of which are variable, has become a single-objective and multi-dimensional optimization design problem with the help of current competitive metaheuristic algorithms. Algorithms have been derived in recent years, have proven their success against existing algorithms, and have not been used in the filter design problem. In addition, in a different study conducted in recent years, among five different objective function pairs that were fabricated from mathematical models that have proven successful, the three most successful objective function pairs were selected based on the relevant study results and these objective function pairs were adapted for the filter and included in the study. Throughout this design optimization process, the filter toolbox in the R2023B version, available as of the MATLAB R2022B version, was used. In addition to the original objective function, the study includes multiple innovations such as the new filter toolbox and current competitive metaheuristic algorithms. During this entire optimization process, the most optimal results are verified by electromagnetic simulation. Considering all these results in the study, the optimization processes performed with the proposed competitive algorithms are an easy, fast and efficient solution for complex and multi-dimensional filter design optimization applications. Additionally, it can be quickly applied to other microwave optimization problems by changing the objective functions.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 4","pages":"1-18"},"PeriodicalIF":1.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thank you to our 2024 reviewers 感谢我们的2024位评审

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1029/2025RS008270

Kazuya Kobayashi;Jothiram Vivekanandan

引用次数: 0

Analysis of sweeping impedance probe measurements in the F-layer of the ionosphere during the occurrence of a mid-latitude spread F event 中纬度扩散F事件发生时电离层F层扫描阻抗探针测量分析

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1029/2024RS008157

P. Chowdhury;E. Spencer;P. Adhya;S. Patra;S. K. Vadepu;P. S. Rayapati

{"title":"Analysis of sweeping impedance probe measurements in the F-layer of the ionosphere during the occurrence of a mid-latitude spread F event","authors":"P. Chowdhury;E. Spencer;P. Adhya;S. Patra;S. K. Vadepu;P. S. Rayapati","doi":"10.1029/2024RS008157","DOIUrl":"https://doi.org/10.1029/2024RS008157","url":null,"abstract":"Plasma Impedance Probes (PIP) are AC instruments that are used to measure and observe resonances and damping features in plasmas. These probes are typically flown on sounding rocket missions studying ionosphere plasma physics. In this work we present a combined circuit—empirical model for the frequency dependent impedance of a monopole probe on a sounding rocket payload that traverses multiple ionospheric layers. The purpose of this model is to resolve some difficulties encountered when interpreting and analyzing PIP measurements made at the higher altitudes during the Tropical STORMS sounding rocket launched from Wallops Island, Virginia, in 2007. In an earlier work (Spencer & Patra, 2015, https://doi.org/10.1002/2015rs005697), we identified the presence of anomalous damping in the measurements above 260 km. Here, we introduce a more detailed model of the plasma probe interaction to explain these observations. The new model incorporates the effect of a sheath, and some additional parallel conductivity elements that dampen the observed impedance in the F-layer of the ionosphere. We show that by accounting for the presence and gradual impact of the parallel conductance elements, the PIP data can be accurately analyzed and interpreted. We hypothesize that secondary electrons with higher mobilities may contribute to the observed effects, and propose future investigations that may be conducted to further understand the observations.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 4","pages":"1-19"},"PeriodicalIF":1.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Front matters 前面问题

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1002/rds.21328

引用次数: 0

Impact of static and mobile scatterers on vehicle-to-vehicle communication channel in rectangular tunnel environment 矩形隧道环境中静态和移动散射体对车对车通信信道的影响

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1029/2025RS008217

Hanene Zormati;Jalel Chebil;Jamel Bel Hadj Tahar

引用次数: 0

Design of a simple and efficient ultra-wideband dipole-structured cross-polarization conversion metasurface 设计一种简单高效的超宽带偶极结构交叉极化转换超表面

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1029/2025RS008218

Faiz ur Rehman;Zicheng Liu;Miao Cao;Yali Zong

引用次数: 0

Correlation between the delay and rise time of VLF/LF amplitudes during 20 solar X-ray flares observed in February 2014 at mid-latitude 2014年2月在中纬度观测到的20次太阳x射线耀斑VLF/LF振幅延迟与上升时间的相关性

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1029/2024RS008103

Y. Liu;M. Füllekrug

{"title":"Correlation between the delay and rise time of VLF/LF amplitudes during 20 solar X-ray flares observed in February 2014 at mid-latitude","authors":"Y. Liu;M. Füllekrug","doi":"10.1029/2024RS008103","DOIUrl":"https://doi.org/10.1029/2024RS008103","url":null,"abstract":"During daylight hours, the concentration of electrons in the ionosphere can be amplified by solar flares, which may subsequently influence the propagation of radio waves. Previous research on Very Low Frequency (VLF) signals focused on X-class and M-class flares. This study expands the scope to include a broader frequency range and C-class flares. During 20-28 February 2014, signals from 15 transmitters (18.3—81.0 kHz) were recorded by a receiver in Bath, UK. 20 solar flares captured during this period are investigated. A new methodology was employed to determine the rise times of the received amplitudes for comparison with the solar X-ray flux recorded by the Geostationary Operational Environmental Satellite geostationary satellite. The time delays between the onset of the X-ray flux and the onset of received amplitude changes are calculated. The general trend shows that shorter delays are linearly correlated to longer rise times of the amplitudes. It is found that the absolute slopes of the linear correlation between the delay and the rise time of M-class flares are larger than those of C-class flares. Two flares showed onset times of received amplitudes preceding the X-ray flux onset. A possible explanation for this is that the received signals might also be influenced by hard X-rays rather than the analyzed soft X-rays. In summary, this study demonstrates the effects of small C-class and M- class flares on the propagation of VLF/LF signals and offers insights for further research on solar flare impacts on radio waves and the lower ionosphere.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 4","pages":"1-16"},"PeriodicalIF":1.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Complex polarizations of ionospheric characteristic waves: A revisit in terms of real representation 电离层特征波的复杂极化：从实际表现的角度重新审视

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-04-01 DOI: 10.1029/2024RS008197

Xun Wang;Yunhua Zhang;Dong Li

{"title":"Complex polarizations of ionospheric characteristic waves: A revisit in terms of real representation","authors":"Xun Wang;Yunhua Zhang;Dong Li","doi":"10.1029/2024RS008197","DOIUrl":"https://doi.org/10.1029/2024RS008197","url":null,"abstract":"The polarizations of ionospheric characteristic waves (CWs) are determined by the two solutions of the quadratic equation in the complex polarization ratio R within the magneto-ionic theory. This paper revisits these solutions and their relationship from the perspective of real representation, given that various real polarization parameter sets are also commonly used and play important parts in characterizing wave polarization. Multiple two-dimensional (2D) real representations are analyzed by re-examining several real two- parameter sets mathematically under a unified framework to prevent possible confusion from examining different parameters in separate frameworks, and by graphically representing the polarizations of the two CWs using 2D polarization plane plots constructed from paired real parameters. A three-dimensional (3D) real representation as the extension of two dimensions is further considered by the mathematical re-examination of the three normalized Stokes parameters for the two CWs and the application of the 3D Poincaré sphere visualization to overcome the non-uniform polarization distribution on the plane plot and the non-unique correspondence between plane point and polarization state. Each real parameter in these real representations is expressed as a function of R. Importantly, the relationship between the same real parameters of the two CWs is derived. Numerical examples presented through the polarization plane or Poincaré sphere plot demonstrate how these real parameters vary with certain ionosphere medium-related quantities and validate the correctness of the derived relationships. The comparison of each real representation with and without collisions reveals the impact of collisions on the real parameters and polarization orthogonality of the two CWs.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 4","pages":"1-27"},"PeriodicalIF":1.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of ground conductivity on VLF wave propagation 地面电导率对甚低频波传播的影响

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-03-01 DOI: 10.1029/2024RS008150

P. Teysseyre;C. Briand;R. Marshall;M. Cohen

{"title":"Effect of ground conductivity on VLF wave propagation","authors":"P. Teysseyre;C. Briand;R. Marshall;M. Cohen","doi":"10.1029/2024RS008150","DOIUrl":"https://doi.org/10.1029/2024RS008150","url":null,"abstract":"Very Low Frequency (VLF, 3–30 kHz) waves propagate long distances in the waveguide formed by the Earth and the lower ionosphere. External sources such as solar flares and lightning discharges perturb the upper waveguide boundary and thereby modify the waves propagating within it. Therefore, studying the propagation of VLF waves within the waveguide enables us to probe the ionospheric response to external forcing. However, the wave propagation also depends on the lower waveguide boundary property, that is, the path conductivity. We tackle two main questions: how accurate should the path conductivity description be to obtain a given accuracy on the ionospheric electron density? Are the currently available ground-conductivity maps accurate enough? The impact of the ground conductivity values and their spatial extension on VLF wave propagation is studied through modeling with the Longwave Mode Propagator code. First, we show that knowledge of the path conductivity value should be more accurate as the ground conductivity decreases, in particular in regions where σ ≤ 10<sup>−3</sup> S/m. Second, we find that wave propagation is strongly sensitive to the spatial extension of ground conductivity path segments: segments of a few tens of km should be included in the path description to maintain below 50% the error on the derived electron density due to the path description. These results highlight the need for an update of the ground conductivity maps, to get better spatial resolution, more accurate values, and an estimate of the time-variability of each region.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 3","pages":"1-16"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143769445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fractional OAM vortex SAR imaging based on chirp scaling algorithm 基于啁啾缩放算法的分数阶OAM涡旋SAR成像

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-03-01 DOI: 10.1029/2024RS008112

Liu Yu;Du Yongxing;Li Baoshan;Qin Ling;Li Chenlu

引用次数: 0