Radio Science最新文献_第7页

Design and ANN-based optimization of compact flexible dual-band spiral wearable antenna (CFDSW) with deformation analysis for body area network and biomedical applications 基于体域网络和生物医学应用的紧密型柔性双频螺旋可穿戴天线（CFDSW）设计与优化及变形分析

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2026RS008642

Pavithra Balaji;Narmadha Ramakrishnan

{"title":"Design and ANN-based optimization of compact flexible dual-band spiral wearable antenna (CFDSW) with deformation analysis for body area network and biomedical applications","authors":"Pavithra Balaji;Narmadha Ramakrishnan","doi":"10.1029/2026RS008642","DOIUrl":"https://doi.org/10.1029/2026RS008642","url":null,"abstract":"This paper presents the increasing desire to have reliable wearable communication systems by suggesting a small, miniaturized antenna functioning in 2.4 and 5.8 GHz ISM (Industrial, Scientific, and Medical) bands, to provide reliable connections in the continuous health monitoring and Body Area Network (BAN) applications. The compact Flexible Dual ISM Band Spiral Wearable (CFDSW) antenna is a compact antenna that uses a CPW fed CPW spiral coiled in a flexible polyimide substrate that has a compact size of 24 × 20 × 0.1 mm3 and is therefore very suitable in conformal wearable devices. An improved CPW ground design is proposed in order to improve impedance matching and bandwidth characteristics. The antenna is assessed on a scale of simulated and measured studies in the free space, bending, on-body and wrist position. The findings show that there are stable dual-band performance with maximum gains of 6.86 dBi at 2.4 GHz and 5.23 dBi at 5.8 GHz as well as simulated radiation efficiencies in the same two bands of about 88%. An Artificial Neural Network (ANN) machine learning optimization framework that employs Bayesian Regularization to train the network on proper prediction of resonance properties is used in order to obtain exact resonance properties with a substantial reduction in computational complexity compared to traditional full-wave optimization. Particular Absorption rate (SAR) of 0.6 W/kg and 0.8 W/kg verify adherence to IEEE and ICNIRP safety standards which proves suitability of the antenna to wearable biomedical BAN setup.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-22"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146777","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 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/rds.70053

引用次数: 0

The multiple launch angle refractivity-from-clutter (MLA-RFC) technique 多发射角杂波折射（MLA-RFC）技术

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-04-02 DOI: 10.1029/2025RS008307

DeGrafth A. Palmore;Caglar Yardim;Qing Wang;David G. Ortiz-Suslow;Ryan Yamaguchi;Jesus Ruiz-Plancarte;Brian K. Haus

{"title":"The multiple launch angle refractivity-from-clutter (MLA-RFC) technique","authors":"DeGrafth A. Palmore;Caglar Yardim;Qing Wang;David G. Ortiz-Suslow;Ryan Yamaguchi;Jesus Ruiz-Plancarte;Brian K. Haus","doi":"10.1029/2025RS008307","DOIUrl":"https://doi.org/10.1029/2025RS008307","url":null,"abstract":"The phenomenon of ducting, influenced by variations in air moisture and temperature above the sea surface, introduces non-standard propagation characteristics that can significantly affect marine communication and radar systems. Therefore, it is necessary to understand these duct formations in order to accurately predict system performance. Atmospheric ducts are characterized by variations in the vertical refractivity profile. The Refractivity-From-Clutter (RFC) technique, known for real-time low tropospheric refractivity profiling, is the focus of this study. This paper explores the concept of employing Multiple Launch Angles (MLA) to enhance RFC inversion precision. The optimal number and distribution of launch angles, multiple-angle cost functions, and corresponding MLA-RFC performance computations are demonstrated via simulations. An MLA-RFC-capable radar is built and deployed during the Coastal Land-Air-Sea Interaction (CLASI) Study in Moss Landing, CA in 2021 and 2022. The Lower ATmospheric PROPagation (LATPROP) radar system is a modified, low-cost marine radar. The capabilities of MLA-RFC are demonstrated using multiple launch angle LATPROP radar measurements collected during the CLASI campaign. The results show that the MLA-RFC method outperforms the single-angle RFC approach by generating reliable launch angle weights and applying them totheinversion algorithm, which leads to reduced bias and RMSerror inevaporation duct height estimates. These weights are derived from the averaged simulated energy trapped in a duct for a given evaporation duct height. Both simulation and experimental results indicate that MLA improves estimation performance by up to 77% and 67%, respectively, compared to the classical single-launch angle RFC.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 3","pages":"1-23"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147588282","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

A compact wideband antenna design for biomedical in-body applications 用于生物医学体内应用的紧凑型宽带天线设计

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2025RS008481

Nadia Salah;Walid S. El-Deeb;A. E. Farahat;K. F. A. Hussein;Azhar A. Hamdi

{"title":"A compact wideband antenna design for biomedical in-body applications","authors":"Nadia Salah;Walid S. El-Deeb;A. E. Farahat;K. F. A. Hussein;Azhar A. Hamdi","doi":"10.1029/2025RS008481","DOIUrl":"https://doi.org/10.1029/2025RS008481","url":null,"abstract":"This paper presents the design, optimization, and experimental assessment of a compact ultrawideband (UWB) antenna tailored for on-body biomedical applications. The proposed antenna features an eight-pointed star-shaped patch with a microstrip-fed configuration and is engineered to operate effectively when placed directly on the human skin surface. The final design achieves a measured impedance bandwidth of 15.6 GHz, spanning from 6.2 to 21.8 GHz, making it suitable for a wide range of high-data-rate and diagnostic applications. A realistic three-layer human tissue model—comprising skin, fat, and muscle—is employed in full-wave simulations to evaluate the antenna's performance under practical conditions. Simulation and measurement results show that the antenna maintains good impedance matching and stable directivity across the operational band, while off-body radiation remains minimal, confirming its near-field operation. The antenna exhibits low realized gain (around −10 dBi) and efficiency (∼2%) due to significant absorption by lossy biological tissues, aligning with its intended function of delivering electromagnetic energy into the body for wireless sensing or in-body communication. Specific absorption rate (SAR) analysis verifies that the antenna complies with safety standards, ensuring its suitability for wearable or implantable biomedical systems. The compact form factor, wideband performance, and robust interaction with human tissues confirm the proposed antenna's potential for advanced biomedical applications.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-20"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146794","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

Enhancing long wave propagation prediction capability through the integration of international reference models 整合国际参考模式，提高长波传播预报能力

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2025RS008597

Yang Xu;Yiwen Liu;Yuhao Wang;Jun Zeng;Wen Xiong;Shuqi Xie;Yangyang Chen

{"title":"Enhancing long wave propagation prediction capability through the integration of international reference models","authors":"Yang Xu;Yiwen Liu;Yuhao Wang;Jun Zeng;Wen Xiong;Shuqi Xie;Yangyang Chen","doi":"10.1029/2025RS008597","DOIUrl":"https://doi.org/10.1029/2025RS008597","url":null,"abstract":"The propagation characteristics of very low frequency (VLF, 3–30 kHz) and low frequency (LF, 30–300 kHz) electromagnetic waves in the Earth ionosphere waveguide (EIWG) are critical to long-distance communication, navigation, and timing. To address limitations of traditional long-wave propagation models (Long Wavelength Propagation Capability), for example, the static representation of ionospheric parameters, this study presents an optimized scheme incorporating international reference models. By incorporating the International Reference Ionosphere model to yield high-resolution ionospheric parameters, coupling it with the NRLMSIS model for calculating neutral atmospheric component densities to enable accurate electron collision frequency derivation, and integrating updated geomagnetic parameters from the 13th International Geomagnetic Reference Field (IGRF-13) model, this approach improves the predictive accuracy of long-wave propagation models. Validation using measured data from the VTX station for six propagation paths shows that the optimized model enables spatiotemporally continuous modeling of ionospheric electron density and collision frequency and eliminates non-physical parameter discontinuities in the original model during dawn-dusk transition periods, with the equivalent reflection height exhibiting physically consistent continuous dynamic evolution. During daytime, the correlation coefficient between predicted and measured field strengths improved from −0.505 ∼ 0.566 to 0.638 ∼ 0.964, while the RMSE over the six paths decreased from 2.111 to 1.1537 dB, which indicates a improvement predictive performance. It should be noted, however, that the model's improvement is relatively limited during nighttime. This study presents a more reliable numerical framework for VLF/LF propagation prediction, thereby conferring practical value for engineering applications.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-16"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146811","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

Interdigital dual band filter design based on surrogate modeling and optimization 基于代理建模和优化的数字间双带滤波器设计

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2025RS008599

Ahmet Uluslu;Bahadir Mustafa Ural

{"title":"Interdigital dual band filter design based on surrogate modeling and optimization","authors":"Ahmet Uluslu;Bahadir Mustafa Ural","doi":"10.1029/2025RS008599","DOIUrl":"https://doi.org/10.1029/2025RS008599","url":null,"abstract":"In recent years, dual-band filters have become critically important in satellite and space communication systems. This study presents an optimized digital twin-based modeling strategy for a small-sized microstrip interdigital dual-band filter. The main innovation of the study is the achievement of high-accuracy S<inf>11</inf> (dB) estimation in the 1-6 GHz frequency range through the combination of reduced data usage via Latin Hypercube sampling and optimization methods. Models created using eight input parameters (including the frequency dimension) were evaluated using MSE, MAE, and R2 error metrics. According to the results, the proposed approach achieved MSE of 1.871, MAE of 0.486, and R2 of 0.810 on the test data, providing a significant performance improvement, especially compared to the SVM-based model (Test MSE: 5.130, R2: 0.329). Furthermore, lower error values and more stable generalization performance were obtained compared to the Ensemble method. The results clearly demonstrate the frequency-dependent variation of S-parameters through target/prediction comparisons. The proposed approach offers an effective and generalizable solution for digital twin-supported modeling in high-dimensional and computationally expensive electromagnetic problems.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-12"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146774","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

Path loss parameters determination for vehicle-to-vehicle communication in urban environment based on real measurements 基于实测的城市环境下车对车通信路径损耗参数确定

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-04-02 DOI: 10.1029/2025RS008556

Hanene Zormati;Hayfa Fhima;Jalel Chebil;Jamel Bel Hadj Tahar

引用次数: 0

Consistent shifts of constant-frequency electromagnetic waves observed by CSES CSES观测到的恒频电磁波的一致位移

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2025RS008516

Ying Han;Qingjie Liu;Jianping Huang;Rui Yan;Jing Yuan;Shanshan Li;Yali Wang;Xuhui Shen

{"title":"Consistent shifts of constant-frequency electromagnetic waves observed by CSES","authors":"Ying Han;Qingjie Liu;Jianping Huang;Rui Yan;Jing Yuan;Shanshan Li;Yali Wang;Xuhui Shen","doi":"10.1029/2025RS008516","DOIUrl":"https://doi.org/10.1029/2025RS008516","url":null,"abstract":"Constant-frequency electromagnetic waves (CFEWs) refer to artificially emitted electromagnetic waves with a constant frequency. Ground stations continuously transmit CFEWs into space at different frequencies. When a satellite passes over a station, it can receive stable CFEWs within a specific frequency range. Based on the frequency shift phenomenon observed in satellite-monitored CFEWs, this study proposes an automatic method for recognizing frequency shifts and extracting frequency data using computer vision. Applied to data from 8 revisit cycles observed by CSES, this method recognized and calculated the center frequencies of three CFEWs—which exhibited specific frequency shifts of approximately 11.8 kHz, 23.6 kHz, and 17.7 kHz—using a total of 1,602 power spectrograms. The study reveals a consistent pattern of synchronized frequency shifts among the three CFEWs, showing that they tend to shift simultaneously in the same direction—either upward or downward—indicating a coherent response to ionospheric influences. Furthermore, these waves systematically register at higher frequencies in the Eastern Hemisphere. This research establishes an intelligent analytical framework for evaluating signal stability and optimizing anti-interference capabilities in geophysical and weather research, as well as in seismic monitoring systems.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-13"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146838","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

Investigation of geomagnetic field and equatorial electrojet variations using data from low- and midlatitude stations during the solar storms of March and April 2023, and October 2024 2023年3月、4月和2024年10月太阳风暴期间中低纬度站资料对地磁场和赤道电喷流变化的研究

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2025RS008505

Lok Nath Sharma;Binod Adhikari;Andrés Calabia Aibar;Ananta Panthi

{"title":"Investigation of geomagnetic field and equatorial electrojet variations using data from low- and midlatitude stations during the solar storms of March and April 2023, and October 2024","authors":"Lok Nath Sharma;Binod Adhikari;Andrés Calabia Aibar;Ananta Panthi","doi":"10.1029/2025RS008505","DOIUrl":"https://doi.org/10.1029/2025RS008505","url":null,"abstract":"In this work, we investigate geomagnetic field and equatorial electrojet variations over Atlantic, Asian, and South American sectors during the storms of March and April 2023, and October 2024 using geomagnetic field data from six ground-based stations. To gain insights and better understanding of the processes of the low-latitude ionosphere and responses to interplanetary disturbances, we investigate solar and geomagnetic indices through cross-correlation and Continuous Wavelet Transform (CWT) analyses. During all three storms, Interplanetary Magnetic field (IMF) B<inf>z</inf> component rapidly turned southward in the main phase, while solar wind velocity (V<inf>sw</inf>) and dynamic pressure (P<inf>sw</inf>) increased largely, generating Prompt Penetration Electric Fields (PPEFs) and Disturbance Dynamo Electric Fields (DDEFs). These external drivers controlled the Equatorial Electrojet (EEJ) showing pronounced longitudinal and local time dependency. Atlantic sector shows large correlations >0.9 between IMF B<inf>z</inf> and EEJ throughout the main phase of March and October storms, whereas the Asian and South American sectors show correlations in the range — 0.6 to — 0.7, and 0.7 to 0.8 respectively, during these storms. The CWT analysis of the EEJ variations for all sectors shows well-defined periodicities at 2–4 hr and 4–8 hr, indicating persistent, large-scale modulations in the equatorial ionospheric current system. This study shows that longitudinal EEJ variations during storms are affected by a complex combination of IMF B<inf>z</inf> direction, storm phase, local time, and regional electrodynamic conditions.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-21"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146805","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

Radio propagation in railway corridors through dense forests-measurement and modeling at 460 MHz 铁路走廊中穿过茂密森林的无线电传播——460兆赫的测量和建模

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-04-02 DOI: 10.1029/2025RS008362

Carlos Alberto Sanches;André Felipe Henriques Librantz;Peterson Adriano Belan

{"title":"Radio propagation in railway corridors through dense forests-measurement and modeling at 460 MHz","authors":"Carlos Alberto Sanches;André Felipe Henriques Librantz;Peterson Adriano Belan","doi":"10.1029/2025RS008362","DOIUrl":"https://doi.org/10.1029/2025RS008362","url":null,"abstract":"Current train signaling systems are being replaced by advanced systems like Communications Based Train Control, European Rail Traffic Management System, and Positive Train Control, which rely on radio networks. However, railways operating in dense forest environments face unique challenges for wireless systems due to high levels of signal attenuation, reflection, and diffraction caused by dense vegetation. The lack of comprehensive real-world data makes it difficult to design systems in such areas. This study presents measurements performed at 460 MHz in a dense forest environment and compares the results with predictions from two models, irregular terrain model and ITU-R (International Telecommunication Union) P.1812, with and without adjustments for vegetation attenuation using ITU-R P.833. Measurements were conducted in Brazil, using a transmitter antenna in a railway corridor and a mobile antenna on a moving locomotive. Our findings indicate that while predicting wireless performance in dense forests is feasible, the best model still had a mean absolute error of 7.43 dB, underscoring the challenges of accurate signal prediction in such environments.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 3","pages":"1-9"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147588297","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