Radio Science最新文献_第2页

A software tool for the true height analysis of ionograms using the iterative gradient correction (IGC) method 使用迭代梯度校正法（IGC）分析离子图真实高度的软件工具

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-10-01 DOI: 10.1029/2024RS007955

M. Ankita;S. Tulasi Ram

{"title":"A software tool for the true height analysis of ionograms using the iterative gradient correction (IGC) method","authors":"M. Ankita;S. Tulasi Ram","doi":"10.1029/2024RS007955","DOIUrl":"https://doi.org/10.1029/2024RS007955","url":null,"abstract":"Deriving the precise true height electron density profile from the measured ionosonde virtual heights is quite a challenging problem. Recently, Ankita and Tulasi Ram (2023, https://doi.org/10.1029/2023RS007808) presented a new method, Iterative Gradient Correction (IGC) method, for true height analysis that uses HF radio wave propagation path computations to reconstruct the true height profile. Through iterative corrections on electron density gradients between successive points, the IGC method minimizes errors below a specified tolerance at each point and reconstructs a complete electron density profile. The derived profiles from the IGC method are found to be accurate when compared with Incoherent Scatter Radar and Global Navigation Satellite System—Radio Occultation observations. To facilitate true height analysis by IGC method for a wider user community, a MATLAB-based software has been developed and is outlined in this report. The software can be installed on any Windows platform and is designed with a user-friendly interface for easy and efficient application by the users. It can analyze multiple scaled ionograms in a single run and outputs the real height profiles in ASCII format. Further, the software also captures important ionospheric parameters such as the base altitudes and peak frequencies of E- and F-layers (e.g., hE, hF, foE, and foF2) etc., from the computed true height profiles and tabulates in a separate output file for the ready use. The software also provides the option for extrapolation of true height profile into top-side ionosphere up to a user-specified height and reconstructs the complete vertical electron density profile.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 10","pages":"1-10"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595842","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

Fast joint DOA and inter-subarray errors estimation in partly calibrated arrays 部分校准阵列中的快速联合 DOA 和子阵间误差估计

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-10-01 DOI: 10.1029/2024RS008061

Qi Song;Feng-Gang Yan;Xiang-Tian Meng;Bing-Xia Cao;Ming Jin

引用次数: 0

Rectangular microstrip with co-planar corner loading: advanced antenna and array design for high cross-polar isolation across all radiation planes 带有共平面角加载的矩形微带：先进的天线和阵列设计，实现所有辐射平面的高跨极性隔离

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-10-01 DOI: 10.1029/2024RS008027

D. Dutta;D. Guha;C. Kumar

引用次数: 0

Electron density profile derived from ionogram using ray tracing inversion method 利用射线追踪反演法从电离图中得出电子密度曲线

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-10-01 DOI: 10.1029/2024RS008086

Qi Jiang;Jiuhou Lei;Xinan Yue;Dexin Ren;Fuqing Huang;Xiaoli Luan;Guozhu Li

{"title":"Electron density profile derived from ionogram using ray tracing inversion method","authors":"Qi Jiang;Jiuhou Lei;Xinan Yue;Dexin Ren;Fuqing Huang;Xiaoli Luan;Guozhu Li","doi":"10.1029/2024RS008086","DOIUrl":"https://doi.org/10.1029/2024RS008086","url":null,"abstract":"The ionosonde is widely used for detecting electron density profiles below the F2 peak altitude. Extracting precise profiles from ionograms is crucial, as it serves as a significant data source for ionospheric studies and applications. In our study, we utilized the ray tracing profile inversion method (RTPI) to derive more realistic electron density profiles from the ionosonde observations. By comparing the electron density profiles inverted by RTPI method with and without geomagnetic field against the profiles observed by Incoherent Scatter Radar (ISR) plasma lines, we validated the high precision of the RTPI with magnetic field effect method. The results showed that the average height difference and average peak height difference between profiles inverted by RTPI and plasma line observations are less than 10 and 5 km, respectively. Additionally, we quantified the errors associated with the geomagnetic field effect. It would cause an ~8—10 km overestimation in true height and a ~ 10%—15% underestimation in electron density if the geomagnetic field effect is not considered. These errors induced by the magnetic field accumulate with the frequency of the radio waves. Moreover, we conducted a comparative analysis of simulated echo traces using profiles with different E-layer shapes. It was demonstrated that the key parameters of the bottom structure have a significant impact on ionogram retrieval, while the E-layer shape has negligible influence on inversion. Furthermore, we analyzed echo traces simulated using ray tracing with and without collision. The collision effect has weak effect on the delay of the radio waves.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 10","pages":"1-13"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595903","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

Revealing inconsistencies in ROTI index using multi-GNSS constellation measurements: impact of sampling rates and time window 利用多重全球导航卫星系统星座测量揭示 ROTI 指数的不一致性：采样率和时间窗口的影响

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-10-01 DOI: 10.1029/2024RS007982

Yi Sui;Zhe Yang;Weijia Zhan

{"title":"Revealing inconsistencies in ROTI index using multi-GNSS constellation measurements: impact of sampling rates and time window","authors":"Yi Sui;Zhe Yang;Weijia Zhan","doi":"10.1029/2024RS007982","DOIUrl":"https://doi.org/10.1029/2024RS007982","url":null,"abstract":"Understanding ionospheric irregularities and their dynamics is crucial, with the rate of change of the total electron content index (ROTI) serving as a significant metric for this purpose. However, inconsistencies in ROTI magnitudes have been noted when sampled at one-second interval across various Global Navigation Satellite System (GNSS) receivers. This study presents a detailed statistical analysis to investigate inconsistencies in ROTI using multi-GNSS observations in conjunction with four distinct GNSS receiver types. Various factors affecting the ROTI inconsistencies among receivers were examined, including differences in sampling rates (1, 5, 15, and 30 s), and varying time window widths (1, 2, and 5 min). By examination of data obtained from GNSS receivers with zero or short baselines on a global scale, the analysis uncovered substantial variations in multi-GNSS ROTI values across the four assessed receiver types. The main findings suggest that reducing the sampling rate reduces the inconsistencies in the magnitude of ROTI, particularly at lower sampling rates. This reduction can be attributed to the exclusion of high-frequency components in the ROTI spectrum. Interestingly, the width of the time window is found to have minimal impact on the ROTI magnitude. The study also shows a direct correlation between a larger magnitude of ROTI and the increased noise in the signals tracked by receivers. These results emphasize the importance of considering sampling rates and GNSS receiver types when utilizing ROTI to investigate ionospheric irregularities.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 10","pages":"1-18"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595807","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

An instrument error budget for space-based absolute flux measurements of the sky synchrotron spectrum below 20 MHz 对 20 兆赫以下天空同步辐射光谱进行天基绝对通量测量的仪器误差预算

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-09-01 DOI: 10.1029/2023RS007824

J. Rolla;A. Romero-Wolf;T. J. W. Lazio

引用次数: 0

A systematic review of meta-surface based antennas for Thz applications 基于元表面的 Thz 应用天线系统综述

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-09-01 DOI: 10.1029/2024RS007980

Nipun Sharma;Amrit Kaur

{"title":"A systematic review of meta-surface based antennas for Thz applications","authors":"Nipun Sharma;Amrit Kaur","doi":"10.1029/2024RS007980","DOIUrl":"https://doi.org/10.1029/2024RS007980","url":null,"abstract":"The growing demand for advanced wireless communication, high-resolution imaging, and innovative medical applications in the Terahertz (THz) frequency range has driven remarkable developments in meta-surface-based antennas. This comprehensive review delves into the cutting-edge advancements, novel designs, and practical applications of meta-surfaces in the THz spectrum. The review begins by exploring the materials employed in meta-surfaces and their crucial role in achieving efficient THz operation. It delves into the realm of polarization diversity, revealing innovative approaches to harnessing the potential of meta-surfaces for polarization control and conversion. A key area of focus is beam-steering technology, with a thorough investigation into beam-steering techniques that have significant implications for enhancing wireless communication, high-resolution imaging, and the internet of things. The paper highlights the potential of these techniques in addressing real-world challenges and advancing THz technology. Furthermore, this review provides an in-depth examination of the innovative antenna designs tailored for THz applications, shedding light on their characteristics and benefits. It also explores the exciting possibilities of THz technology within the medical field, including precise bio sensing and cancer cell detection.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 9","pages":"1-22"},"PeriodicalIF":1.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377151","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

Low-profile miniaturized wideband circularly polarized monopole and MIMO antennas using characteristic mode analysis for wireless communication 利用特性模式分析实现用于无线通信的小型化宽带圆极化单极和多输入多输出天线

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-09-01 DOI: 10.1029/2024RS008030

Z. Ding;J. Cao;J. Yu;Nasimuddin Nasimuddin;M. Y. Chia;S. Fei;H. Wang

{"title":"Low-profile miniaturized wideband circularly polarized monopole and MIMO antennas using characteristic mode analysis for wireless communication","authors":"Z. Ding;J. Cao;J. Yu;Nasimuddin Nasimuddin;M. Y. Chia;S. Fei;H. Wang","doi":"10.1029/2024RS008030","DOIUrl":"https://doi.org/10.1029/2024RS008030","url":null,"abstract":"Low-profile miniaturized wideband circularly polarized (CP) monopole and multiple-input-multiple-output (MIMO) antennas using characteristic mode analysis (CMA) are presented. The antennas are constructed with a microstrip feeding line, a slot, and a branch, which positions the transmission line perpendicularly to the branch to achieve CP. The CP characteristic is realized through a characteristic angle (CA) difference of approximately 90° at three mode significance (MS) intersections across four modes. CMA provides both theoretical analysis and design guidance for these antennas. The antennas were fabricated and tested, with dimensions of 0.48λ\u0000<inf>0</inf>\u0000 × 0.48λ\u0000<inf>0</inf>\u0000 × 0.03λ\u0000<inf>0</inf>\u0000 and 0.47λ\u0000<inf>0</inf>\u0000 × 0.47λ\u0000<inf>0</inf>\u0000 × 0.03λ\u0000<inf>0</inf>\u0000, where λ\u0000<inf>0</inf>\u0000 represents the freespace wavelength. Measurements indicate that the monopole antenna achieves a —10 dB impedance bandwidth (IBW) from 3.2 to 8.4 GHz (89.7% relative bandwidth), a 3 dB axial ratio bandwidth (ARBW) from 3.6 to 5.1 GHz (34.5%), and a peak gain of 6.6 dBic. The MIMO antenna has a —10 dB IBW from 3.1 to 8.2 GHz (90.3%), a 3 dB ARBW from 3.2 to 6 GHz (60.9%), and a peak gain of 5.1 dBic. Both antennas feature a low profile, ultra-wideband IBW, broadband ARBW, and miniaturized design, making them suitable for wideband wireless communication applications.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 9","pages":"1-16"},"PeriodicalIF":1.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142376783","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

Exploring AI progress in GNSS remote sensing: A deep learning based framework for real-time detection of earthquake and tsunami induced ionospheric perturbations 探索全球导航卫星系统遥感领域的人工智能进展：基于深度学习的地震和海啸电离层扰动实时检测框架

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-09-01 DOI: 10.1029/2024RS008016

Michela Ravanelli;Valentino Constantinou;Hamlin Liu;Jacob Bortnik

{"title":"Exploring AI progress in GNSS remote sensing: A deep learning based framework for real-time detection of earthquake and tsunami induced ionospheric perturbations","authors":"Michela Ravanelli;Valentino Constantinou;Hamlin Liu;Jacob Bortnik","doi":"10.1029/2024RS008016","DOIUrl":"https://doi.org/10.1029/2024RS008016","url":null,"abstract":"Global Navigation Satellite System Ionospheric Seismology investigates the ionospheric response to earthquakes and tsunamis. These events are known to generate Traveling Ionospheric Disturbances (TIDs) that can be detected through GNSS-derived Total Electron Content (TEC) observations. Real-time TID identification provides a method for tsunami detection, improving tsunami early warning systems (TEWS) by extending coverage to open-ocean regions where buoy-based warning systems are impractical. Scalable and automated TID detection is, hence, essential for TEWS augmentation. In this work, we present an innovative approach to perform automatic real-time TID monitoring and detection, using deep learning insights. We utilize Gramian Angular Difference Fields (GADFs), a technique that transforms time-series into images, in combination with Convolutional Neural Networks (CNNs), starting from VARION (Variometric Approach for Real-time Ionosphere Observation) real-time TEC estimates. We select four tsunamigenic earthquakes that occurred in the Pacific Ocean: the 2010 Maule earthquake, the 2011 Tohoku earthquake, the 2012 Haida-Gwaii, the 2015 Illapel earthquake. The first three events are used for model training, whereas the out-of-sample validation is performed on the last one. The presented framework, being perfectly suitable for real-time applications, achieves 91.7% of F1 score and 84.6% of recall, highlighting its potential. Our approach to improve false positive detection, based on the likelihood of a TID at each time step, ensures robust and high performance as the system scales up, integrating more data for model training. This research lays the foundation for incorporating deep learning into real-time GNSS-TEC analysis, offering a joint and substantial contribution to TEWS progression.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 9","pages":"1-18"},"PeriodicalIF":1.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142376782","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 simple noncontact soil moisture probe for weather and climate applications 用于天气和气候应用的简易非接触式土壤水分探头

IF 1.6 4区地球科学

Radio Science Pub Date : 2024-09-01 DOI: 10.1029/2023RS007857

A. G. Voronovich;P. E. Johnston;R. J. Lataitis

引用次数: 0