Radio Science最新文献

Front matters 前面问题

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-09-01 DOI: 10.1002/rds.21333

引用次数: 0

Study on the variation of low-frequency time code signals during medium to large solar flare events 中大型太阳耀斑事件中低频时码信号的变化研究

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-09-01 DOI: 10.1029/2024RS008186

Zhen Qi;Xiaoqian Ren;Qiang Liu;Fan Zhao;Luxi Huang;Yingming Chen;Xin Wang;Langlang Cheng;Yuping Gao;Ping Feng

{"title":"Study on the variation of low-frequency time code signals during medium to large solar flare events","authors":"Zhen Qi;Xiaoqian Ren;Qiang Liu;Fan Zhao;Luxi Huang;Yingming Chen;Xin Wang;Langlang Cheng;Yuping Gao;Ping Feng","doi":"10.1029/2024RS008186","DOIUrl":"https://doi.org/10.1029/2024RS008186","url":null,"abstract":"This study is based on the 68.5 kHz signal transmitted by China's low-frequency time code time service system (BPC) and systematically researches the effects of medium to large solar flares (M/X-class) on low-frequency time code signals. By analyzing the field strength and timing deviation data of the BPC signal during 20 typical flare events, the study reveals the variation patterns of low-frequency time code signals under disturbances from medium to large solar flares. Case analyses indicate that, during such flares, the BPC signal intensity exhibits two response patterns: a single-valley structure and a double-valley structure. The BPC signal response is divided into two stages—a rapid change phase and a gradual change phase—which show a strong linear relationship with the development of the solar flare. Meanwhile, the BPC timing deviation displays a bipolar pulse characteristic, and after the flare, the instability in signal performance is closely associated with the double-valley response in field strength. These phenomena suggest that the changes in the BPC time code signal are closely related to the effects of ionospheric disturbances during solar flares on the superposition characteristics of the BPC ground-wave and sky-wave signals. This first systematic investigation analyzes low-frequency time-code signal variation during medium-to-large solar flares, revealing their response characteristics. It provides significant insights into the low-frequency time-code signal propagation-solar activity association and lays a solid theoretical foundation for improving time-service stability and reliability.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 9","pages":"1-17"},"PeriodicalIF":1.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196046","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

Examinations of metal meshing surfaces to retain good optical transparency in different electromagnetic shielding effectiveness 检验金属网格表面在不同的电磁屏蔽效果下保持良好的光学透明性

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-09-01 DOI: 10.1029/2024RS008108

H. T. Chou;C. Y. Chang;C. Y. Chou;S. Kawdungta;D. Torrungrueng

引用次数: 0

Integrating drones with digital twins for aerial remote sensing 将无人机与数字孪生体集成，用于航空遥感

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-08-01 DOI: 10.1029/2023RS007700

Izzat Al-Darraji;Fazal Qudus Khan;Tania Tareq Salim;Georgios Tsaramirsis;Houssem Jerbi;Ayad A. Kakei;Ayad Ghany Ismaeel

{"title":"Integrating drones with digital twins for aerial remote sensing","authors":"Izzat Al-Darraji;Fazal Qudus Khan;Tania Tareq Salim;Georgios Tsaramirsis;Houssem Jerbi;Ayad A. Kakei;Ayad Ghany Ismaeel","doi":"10.1029/2023RS007700","DOIUrl":"https://doi.org/10.1029/2023RS007700","url":null,"abstract":"Drones are highly autonomous, remote-controlled platforms capable of performing a variety of tasks in diverse environments. A digital twin (DT) is a virtual replica of a physical system. The integration of DT with drones gives the opportunity to manipulate the drone during a mission. In this paper, the architecture of DT is presented in order to explain how the physical environment can be represented. The techniques via which drones are collecting the necessary information for DT are compared as a next step to introduce the main methods that have been applied in DT progress by drones. The findings of this research indicated that the process of incorporating DTs into drones will result in the advancement of readings from all sensors, control code and intelligence. This can be executed on the DTs, remote control for the performance of complex tasks in a variety of application environments, and simulation on the DTs without having an effect on the actual drone. On the other hand, in order to develop three-dimensional representations of structures and construction sites, a method known as photogrammetry is used to generate these models employing drones as aerial scanners. In spite of this, there are a number of technological and social-political obstacles that should be taken in consideration. These challenges include the interoperability of different sensors, the creation of efficiently optimized data processing algorithms, and concerns over data privacy and security.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 8","pages":"1-11"},"PeriodicalIF":1.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934374","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

Validation of ANCHOR ionospheric data assimilation model using incoherent scatter radars 基于非相干散射雷达的ANCHOR电离层数据同化模型验证

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-08-01 DOI: 10.1029/2024RS008125

Andrew M. Pepper;Victoriya V. Forsythe;Sarah E. McDonald;Katherine A. Zawdie

{"title":"Validation of ANCHOR ionospheric data assimilation model using incoherent scatter radars","authors":"Andrew M. Pepper;Victoriya V. Forsythe;Sarah E. McDonald;Katherine A. Zawdie","doi":"10.1029/2024RS008125","DOIUrl":"https://doi.org/10.1029/2024RS008125","url":null,"abstract":"ANCHOR is a novel data assimilation model developed at the U.S. Naval Research Laboratory for nowcasting ionospheric parameters relevant to space weather applications. ANCHOR incorporates electron density observations from ionosondes, Abel inverted radio occultation (RO) data, and ground-based GNSS receiver data into a PyIRI-driven model background using the Kalman filter technique. The purpose of this study is to validate the estimated model parameters with parameters derived from electron density observations from incoherent scatter radars (ISR) at various levels of solar activity. Four distinct events were identified from a 6-year data set spanning from 2018 to 2024 collected from four operating ISRs located at varying latitudes west of the prime meridian: Arecibo, Jicamarca, Millstone Hill, and Poker Flat. These events span a range of solar activity levels, with two events at low solar activity, one at moderate and one at high solar activity, each with data coverage from at least two radars. Parameter extraction is achieved by fitting Epstein functions to the electron density profiles, where the peak density (NmF2), peak altitude (hmF2), and the bottomside and topside thickness parameters are simultaneously optimized to characterize the F2 layer. The ISR-extracted parameters are used to directly compare with the model outputs using the root mean square error (RMSE) analysis method. Up to 75% improvement relative to the background model for NmF2, hmF2, and thickness parameters with consistency across all latitudes is found. Additionally, the ANCHOR assimilative model was compared to PyIRTAM model, showing a good agreement between the performances of both systems.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 8","pages":"1-20"},"PeriodicalIF":1.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934379","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

Enhanced meteoroid trajectory and speed reconstruction using a forward scatter radio network: Pre-t0 phase technique and uncertainty analysis 利用前向散射无线电网络增强流星体轨迹和速度重建：前0相位技术和不确定性分析

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-08-01 DOI: 10.1029/2025RS008305

Joachim Balis;Hervé Lamy;Michel Anciaux;Emmanuel Jehin;Johan De Keyser;Daniel Kastinen;Peter G. Brown

引用次数: 0

On phase screen models for scintillation diagnostics 闪烁诊断的相屏模型

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-08-01 DOI: 10.1029/2024RS008204

Charles Rino;Charles Carrano;Dmytro Vasylyev;Theodore Beach;Brian Breitsch;Yu Morton;Keith Groves

{"title":"On phase screen models for scintillation diagnostics","authors":"Charles Rino;Charles Carrano;Dmytro Vasylyev;Theodore Beach;Brian Breitsch;Yu Morton;Keith Groves","doi":"10.1029/2024RS008204","DOIUrl":"https://doi.org/10.1029/2024RS008204","url":null,"abstract":"Advanced global navigation satellite system receivers typically report intensity scintillation indices, phase scintillation indices, and rate of total electron content change indices (ROTI). Extensive regional measurements are being accumulated and made available as diagnostic resources. Although each parameter is derived independently from measured intensity and phase time series, to the extent that ionospheric structure is the source of the scintillation manifestations, more definitive scintillation diagnostics can be predicted for structure characterized by a two-component inverse power law spectral density function. This paper derives theoretical predictions of main statistical characteristics of signal amplitude and phase that has been randomly modulated while propagating through two-dimensional random phase screens. An irregularity parameter estimation procedure is developed that generates maximum likelihood parameter estimates. It is shown that the estimated parameters reconcile theoretical prediction with reasonable accuracy. Phase-screen simulations are used to verify the theoretical predictions. The scintillation model is embedded in a generic signal model with additive noise, which allows direct application to appropriately detrended intensity and phase measurements.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 8","pages":"1-17"},"PeriodicalIF":1.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934522","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

Calibration of electrically short antennas using the l = 2 spherical harmonic expansion coefficients of the radio brightness distribution on the sky between 0.5 and 6.8 MHz 利用0.5 ~ 6.8 MHz天空射电亮度分布的l = 2球谐展开系数标定电短天线

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-08-01 DOI: 10.1029/2024RS008137

Brent Page;Alain Lecacheux;Marc Pulupa;Stuart D. Bale

{"title":"Calibration of electrically short antennas using the l = 2 spherical harmonic expansion coefficients of the radio brightness distribution on the sky between 0.5 and 6.8 MHz","authors":"Brent Page;Alain Lecacheux;Marc Pulupa;Stuart D. Bale","doi":"10.1029/2024RS008137","DOIUrl":"https://doi.org/10.1029/2024RS008137","url":null,"abstract":"A space-borne radio-frequency antenna is typically located in the vicinity of a conductive spacecraft body that influences its beam. Also, at wavelengths that greatly exceed the sizes of such an antenna and spacecraft, the antenna is expected to have the beam of an equivalent short dipole. This type of beam varies with direction as sin<sup>2</sup>(ζ), where ζ is the polar angle relative to the antenna's electrical axis. We describe a Markov Chain Monte Carlo method for fitting for this axis and apply it to measurements from Parker Solar Probe's four whip antennas. Depending on how the antennas are connected to the spacecraft's radio receiver, their voltages are processed individually for “monopole” measurements or differenced for “dipole” measurements. We find with a reduced χ<sup>2</sup> = 1.01 that the electrical axes of the dipoles deviate from the whip axes by 0° — 4°. A byproduct of this fit is a measurement of the l = 2 spherical harmonic expansion coefficients of the brightness distribution on the sky. We utilize this measurement to in turn determine the electrical axes of the monopoles from a much smaller data set. These are found to be deflected ≈ 27° away from the whips. Rheometric calibration and computational electromagnetic simulations of the antenna system corroborate the fits. All of the analyzed data were captured with the spacecraft solar array deployed, which perturbs the electrical axes of the antennas by a few degrees.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 8","pages":"1-19"},"PeriodicalIF":1.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934544","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

The improvement and implementation of theory of Maxwellian circuit 麦克斯韦电路理论的改进与实现

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-08-01 DOI: 10.1029/2024RS008205

Yuhang Ji;Fan Rong;Liping Yan;Xiang Zhao

{"title":"The improvement and implementation of theory of Maxwellian circuit","authors":"Yuhang Ji;Fan Rong;Liping Yan;Xiang Zhao","doi":"10.1029/2024RS008205","DOIUrl":"https://doi.org/10.1029/2024RS008205","url":null,"abstract":"The classical transmission line (TL) equations are constrained by the quasi-TEM (Transverse Electromagnetic) approximation. The Theory of Maxwellian Circuit (TMC) establishes a generalized TL equation. It employs full-wave analysis results to fit the distributed parameters of the TL equation, thereby determining a generalized TL equation form that is not limited to the quasi-TEM approximation. TMC can be regarded as a data-driven modeling approach. Furthermore, the TL equation formulated by TMC can serve as a reference for other generalized TL equations in terms of both equation form and parameters, including coefficient terms and inhomogeneous terms. This paper analyzes the distributed parameters and source terms in the differential equations of TMC and improves the form of the source terms, which implies corresponding changes in the values of the distributed parameter terms. Numerical simulations reveal that the improved TMC model offers improved accuracy in predicting current distribution along TLs. Furthermore, several technical details related to the numerical implementation of TMC are presented, including avoiding dealing directly with non-smooth positions in TLs, using a set of boundary conditions with weak ill-conditioning, and choosing the range of [λ/40, λ/20] as the length of segments based on computational accuracy and efficiency. These considerations represent novel contributions not previously mentioned. These studies will aid in applying machine learning to transmission line modeling and analysis and advance the development of generalized TL equations and theory.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 8","pages":"1-13"},"PeriodicalIF":1.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934566","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

AU-Ray program for modeling radio wave propagation in the ionosphere 模拟无线电波在电离层传播的AU-Ray程序

IF 1.5 4区地球科学

Radio Science Pub Date : 2025-08-01 DOI: 10.1029/2024RS008209

E. A. O. Hirvonen;K. Kauristie;E. Kallio

{"title":"AU-Ray program for modeling radio wave propagation in the ionosphere","authors":"E. A. O. Hirvonen;K. Kauristie;E. Kallio","doi":"10.1029/2024RS008209","DOIUrl":"https://doi.org/10.1029/2024RS008209","url":null,"abstract":"This paper presents a numerical ray-tracing model, AU-Ray, for simulating the HF/VHF radio wave propagation in the ionosphere. AU-Ray operates in fully three-dimensional magnetoionic conditions along similar principles as applied in some other widely used ray-tracing codes (e.g., PHaRLAP and Proplab-Pro). The AU-Ray software has been developed in C++ and built entirely on open-source packages, which makes it an efficient standalone alternative for other ray-tracing models. The model can handle customized user-defined sources for the ionospheric background conditions, in addition to the well-known empirical models. Use cases for AU-Ray include analyzing satellite and ground-based measurements, investigating ionospheric anomalies, and supporting real-time operations. Validation against other ray-tracing models demonstrates that AU-Ray provides consistent results with Proplab-Pro and PHaRLAP and has similar performance in computational efficiency as PHaRLAP, which is significantly higher than that of Proplab-Pro. As an additional feature when compared to PHaRLAP's capabilities AU-Ray's photon mapping tool allows operations to solve large quantities of rays for detailed propagation maps in experimental background conditions.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 8","pages":"1-14"},"PeriodicalIF":1.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934395","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