Radio Science最新文献

{"title":"Statistical Analysis of Off-Great Circle Radio Wave Propagation in the Polar Cap","authors":"T. G. Cameron, R. A. D. Fiori, G. W. Perry, A. Spicher, T. Thayaparan","doi":"10.1029/2023rs007897","DOIUrl":"https://doi.org/10.1029/2023rs007897","url":null,"abstract":"High latitude ionospheric density structures such as polar cap patches and arcs are capable of deflecting high frequency (HF) radio waves to off-great circle paths, and are likely detrimental to technologies dependent on HF radio propagation. In this study, nearly 2.5 years of 4.6–14.4 MHz data from a multi-frequency HF radio link between Qaanaaq, Greenland and Alert, Canada are used to investigate high-latitude off-great circle propagation in the polar cap. After an example of HF radio propagation affected by polar cap patches is shown in detail, a statistical analysis of the occurrence and impacts of off-great circle deflections in the polar cap is presented. Off-great circle propagation is shown to be increasingly common with increasing frequency up to 11.1 MHz, such that averaged over 1 year, received 11.1 MHz signals experienced deflections >30° from the great circle direction 65.6% of the time. The occurrence of these deflections across the year is shown to be at a maximum in the winter, while occurrence across the day varies with season. Trends across both time of day and time of year for 11.1 and 14.4 MHz deflections are consistent with polar cap patch occurrence trends. Off-great circle deflections are shown to be associated with increased time-of-flights, a larger range of positive and negative Doppler shifts, increased Doppler spreads, and lower signal-to-noise ratios. These results are discussed in the context of ionospheric phenomena in the polar cap, and implications for over-the-horizon radars operating at high latitudes.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"32 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140599467","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}

{"title":"Thank You to Our 2023 Reviewers","authors":"Sana Salous, Kazuya Kobayashi","doi":"10.1029/2024rs008003","DOIUrl":"https://doi.org/10.1029/2024rs008003","url":null,"abstract":"<p>Science operates best by sharing accurate new knowledge in clear ways. To check our assumptions, our methods, and our interpretations of the observations, experiments, analyses, and calculations that we do, we ask experts who were not involved in the study to critically evaluate our work. We call this peer review. They look for completeness, accuracy, whether work is new, and how clearly we have written the descriptions. We continue to be humbled by the time, effort, and careful insights that our colleagues share with each other through the process of peer review. Thank you all for your efforts toward advancing radio science now and for the future.</p>\u0000<p>Individuals in italics provided three or more reviews for <i>Radio Science</i> during the year.</p>\u0000<p>A</p>\u0000<p>Aaron Chippendale</p>\u0000<p>Abid Khan</p>\u0000<p><i>Abubaker Elobied</i></p>\u0000<p>Adam Beardsley</p>\u0000<p>Adel Thaljaoui</p>\u0000<p>Adnan Cheema</p>\u0000<p>Agri Faturahman</p>\u0000<p><i>Aiswarya RS</i></p>\u0000<p>Ajeet Kumar</p>\u0000<p>Akimasa Hirata</p>\u0000<p>Alan E. E. Rogers</p>\u0000<p>Albane Saintenoy</p>\u0000<p>Alex Chartier</p>\u0000<p>Alex Minetto</p>\u0000<p>Alexander Shvets</p>\u0000<p>Alexei Dmitriev</p>\u0000<p><i>Alexey Oinats</i></p>\u0000<p>Ali Zidour</p>\u0000<p>Alireza Mahmoudian</p>\u0000<p>Alison Moraes</p>\u0000<p>Amir Rezagholi</p>\u0000<p><i>Amjad Iqbal</i></p>\u0000<p>Ana Elias</p>\u0000<p><i>Anand Kumar</i></p>\u0000<p>Andres Romero-Wolf</p>\u0000<p>Andrey Lyakhov</p>\u0000<p>Angelo De Santis</p>\u0000<p>Animesh Maitra</p>\u0000<p><i>Ankan Bhattacharya</i></p>\u0000<p>Ashik Paul</p>\u0000<p><i>Asif Ahmed</i></p>\u0000<p>Asma S</p>\u0000<p>Atsuki Shinbori</p>\u0000<p>Avinash Deshpande</p>\u0000<p>Axel von Engeln</p>\u0000<p><i>Ayman Althuwayb</i></p>\u0000<p>Balaji K</p>\u0000<p>Benjamin Reid</p>\u0000<p>Bing Li</p>\u0000<p>Bo Ai</p>\u0000<p>Brecht De Beelde</p>\u0000<p>Brent Page</p>\u0000<p>Brian Breitsch</p>\u0000<p>C Vedavathi</p>\u0000<p>Carlo Scotto</p>\u0000<p><i>Chandan Kumar Ghosh</i></p>\u0000<p>Chao Xiong</p>\u0000<p>Chaoxian Qi</p>\u0000<p>Charles Naudet</p>\u0000<p>Cherry Ng</p>\u0000<p><i>Chinmoy Bhattacharya</i></p>\u0000<p><i>Christina Arras</i></p>\u0000<p><i>Christopher Volk</i></p>\u0000<p>Conor Brennan</p>\u0000<p>Craig Rodger</p>\u0000<p>D Sarma Achanta</p>\u0000<p>Daban Kadhim Omar Dabbagh</p>\u0000<p>Dalia Nandi</p>\u0000<p>Daniel Greenway</p>\u0000<p>Daniel Kastinen</p>\u0000<p>Daniel Kouba</p>\u0000<p>Daniel Okoh</p>\u0000<p>Dariia Savelian</p>\u0000<p>Dario Bojanjac</p>\u0000<p>Dario Sabbagh</p>\u0000<p>Dave Laurenson</p>\u0000<p><i>David Hartley</i></p>\u0000<p><i>David Themens</i></p>\u0000<p>Dayang Li</p>\u0000<p>Deepak Singh</p>\u0000<p><i>Dinesh Jackson Samuel Samuel</i></p>\u0000<p>Dmitrii Solomitckii</p>\u0000<p>Dominique Lesselier</p>\u0000<p><i>Dustin Buccino</i></p>\u0000<p>Edmund Spencer</p>\u0000<p>Eduardo Araujo-Pradere</p>\u0000<p>Elnour Badria</p>\u0000<p>Enrico Testi</p>\u0000<p>Ercha Aa</p>\u0000<p>Euclides Chuma</p>\u0000<p>François Lavoué</p>\u0000<p>Gareth Chisham</p>\u0000<p>Gargi Rakshit</p>\u0000<p><i>Gerald Arada</i></p>\u0000<p><i>Giada Battaglia</i></p>\u0000<p><i>Giuseppe Mazzarella</i></p>\u0000<p>Glenn Hussey</p>\u0000<p><i>Guanyi Ma</i></p>\u0000<p>Gunter Stober</p>\u0000<p>Guobin Yang</p>\u0000<p><i>Guozhu Li</i></p>\u0000<p>H. Adenle</p>\u0000<p>Hai-Sheng Zhao</p>\u0000<p>Haiyang Fu</p>\u0000<p>Hector Garcia Martinez</p>\u0000<p><i>Heidi Morris</i></p>","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"68 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140598983","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}

{"title":"Variation in Total Electron Content Over Ethiopia During the Solar Eclipse Events","authors":"Chali Idosa Uga, Sujan Prasad Gautam, Uluma Edward, Binod Adhikari, Dessalegn Teferi, Ashutosh Giri, Athwart Davis Odhiambo, Ayomide Olabode","doi":"10.1029/2023rs007830","DOIUrl":"https://doi.org/10.1029/2023rs007830","url":null,"abstract":"This work studies variations of ionospheric total electron content (TEC) during four distinct solar eclipse events over the Ethiopia region. Dual-frequency global positioning system (GPS) data obtained from UNAVCO over Addis Ababa (9.036°N, 38.76°E) and Bahir Dar (11.6°N, 37.34°E) stations are used to examine the ionospheric variability during two annular solar eclipses on 15 January 2010 and 1 September 2016, a partial solar eclipse on 4 January 2011, and a hybrid solar eclipse (the eclipse path starts out as annular but later changes to total) on 3 November 2013. The results show a significant decrease in TEC values during the occurrence of the solar eclipses. Specifically, the TEC values are reduced to −20% and −10% during the annular eclipse on 15 January 2010, −33% and −38% during the partial solar eclipse on 4 January 2011, −26% and −24% during the annular solar eclipse on 1 September 2016, over the Addis Ababa and Bahir Dar stations, respectively. There is only minimal change in TEC of −8% and −9% at Addis Ababa and Bahir stations, respectively, during the 3 November 2013 solar eclipse even if the obstruction rate is high over the study area. Furthermore, the study shows that the spatial gradient of TEC reduction varies at different locations, which is attributed to the distinct amount of reduction in solar radiation reaching the Earth's surface, resulting in reduced photo-ionization. Overall, this study provides insightful information about the behavior of the ionospheric TEC during solar eclipses over Ethiopia and emphasizes the use of dual-frequency GPS data in tracking the variations of the TEC.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"6 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140598968","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}

{"title":"Statistical Analysis of Ionospheric Correlation for Shortwave System","authors":"Mingjie Lv, Qiong Tang, Jiandong Qiao, Wei Qiao, Chen Zhou","doi":"10.1029/2023rs007893","DOIUrl":"https://doi.org/10.1029/2023rs007893","url":null,"abstract":"Statistical analysis of the temporal and spatial variations in the ionosphere is necessary to improve the shortwave system. Based on the standardized Euclidean distance algorithm, multisource ionospheric assimilation data, International GNSS Service vertical total electron content data, and ionosonde data are used to statistically analyze the ionospheric correlation distance, and the variation of ionospheric correlation distances with local times, magnetic latitudes, and seasons are obtained. The statistical analysis results show that the zonal ionospheric correlation distance presents minima in the equatorial ionospheric anomaly crest regions. Additionally, the meridional correlation distance in middle magnetic latitudes is greater than that in other regions. The zonal ionospheric correlation distance presents obvious local‐time variability. The variation trends of the meridional and zonal correlation distance during spring and autumn are similar. The patterns of the ionospheric correlation range variation with local times, magnetic latitudes, and seasons can be used to select the optimal locations or spacing for ionosonde stations, shortwave multi‐station systems, and shortwave radio beacons.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"12 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140764226","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}

{"title":"Synthesis of elliptically shaped aperiodic antenna arrays subject to complex design constraints","authors":"J. M. E. Geerarts;G. Theis;A. B. Smolders;D. Caratelli","doi":"10.1029/2023RS007914","DOIUrl":"10.1029/2023RS007914","url":null,"abstract":"State-of-the-art conformal array pattern synthesis techniques typically suffer from a significant computational burden. This article builds upon the auxiliary array pattern synthesis technique, allowing the technique to work on elliptical contours. This deterministic method is both computationally efficient and capable of handling complex design cases with additional design constraints. In order to highlight the versatility and applicability, the method has been applied to an elliptical arc array comprised of Rampart antennas and an elliptical ring array using dipole elements. The results have been validated through full-wave electromagnetic simulations, as well as physical measurements. Both arrays presented show good agreement with the proposed synthesis technique. Highlighting the ability to satisfy additional design constraints, such as enforcing a minimal element spacing or having a controlled beamformer-network complexity.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 5","pages":"1-14"},"PeriodicalIF":1.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141041697","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}

{"title":"Front matters","authors":"","doi":"10.1002/rds.21241","DOIUrl":"https://doi.org/10.1002/rds.21241","url":null,"abstract":"","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 5","pages":"1-2"},"PeriodicalIF":1.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10542685","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141181999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-latitude off-great circle propagation associated with the solar terminator","authors":"T. G. Cameron;R. A. D. Fiori;G. W. Perry;J. J. Ruck;T. Thayaparan","doi":"10.1029/2023RS007917","DOIUrl":"10.1029/2023RS007917","url":null,"abstract":"Large-scale ionospheric gradients associated with the solar terminator can deflect high frequency (HF) radio waves to off-great circle paths during the morning and evening, negatively impacting technologies reliant on HF radio wave propagation. For example, geolocation algorithms used by scientific and military over-the-horizon radars (OTHRs) generally assume on-great circle propagation, and thus lateral deviations from the great-circle path can lead to positioning errors. In this study, radio wave propagation is simulated via 3D numerical ray traces though an empirical, high-latitude model ionosphere initialized for a variety of times of the day and year to explore and quantify high-latitude off-great circle propagation associated with the solar terminator. Analysis of these simulations show large scale east-west ionospheric gradients due to the solar terminator can cause lateral deviations in north-directed propagation paths exceeding 20° at sunrise and sunset depending on radio wave frequency, though the largest portion of received signal power tends to experience maximum deflections of 5°. An exploration of the dependence of propagation direction on deflection shows that propagation paths parallel to the solar terminator tend to experience the largest deflections. Since the solar terminator at high latitudes is at an angle with respect to north in the winter and summer, propagation paths oriented west or east of north can experience larger deflections than north oriented paths at sunrise and sunset during these times of year. Impacts of these diurnal deflections on the operation of OTHR and scientific radar are discussed, as well as possible strategies for mitigating them.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 5","pages":"1-17"},"PeriodicalIF":1.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141140263","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}

{"title":"Application of wide-beam transmission for advanced operations of SuperDARN Borealis radars in monostatic and multistatic modes","authors":"R. A. Rohel;P. Ponomarenko;K. A. McWilliams","doi":"10.1029/2023RS007900","DOIUrl":"10.1029/2023RS007900","url":null,"abstract":"The Super Dual Auroral Radar Network (SuperDARN) consists of more than 30 monostatic high-frequency (HF, 8-20 MHz) radars to study dynamic processes in the ionosphere. SuperDARN provides maps of global-scale ionospheric plasma drift circulation from the mid-latitudes to the poles. The conventional SuperDARN radars consecutively scan through 16 beam directions with a lower limit of 1 minute to sample the entire field of view. In this work, we use the advanced capabilities of the recently developed Borealis digital SuperDARN radar system. Combining a wide transmission beam with multiple narrow reception beams allows us to sample all conventional beam directions simultaneously and to speed up scanning of the entire field-of-view by up to 16 times without noticeable deterioration of the data quality. The wide-beam emission also enabled the implementation of multistatic operations, where ionospheric scatter signals from one radar are received by other radars with overlapping viewing areas. These novel operations required the development of a new model to determine the geographic location of the source of the multistatic radar echoes. Our preliminary studies showed that, in comparison with the conventional monostatic operations, the multistatic operations provide a significant increase in geographic coverage, in some cases nearly doubling it. The multistatic data also provide additional velocity vector components, increasing the likelihood of reconstructing full plasma drift velocity vectors. The developed operational modes can be readily implemented at other fully digital SuperDARN radars.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 5","pages":"1-17"},"PeriodicalIF":1.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141047304","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}

{"title":"Direct digital RF transceiver technology for millimeter-wave DBF systems","authors":"Noriharu Suematsu","doi":"10.1029/2023RS007802","DOIUrl":"https://doi.org/10.1029/2023RS007802","url":null,"abstract":"Digital RF technology has been developed and has been applied to below 6 GHz wireless applications. By replacing the IC die consumptive RF/analog circuit blocks by digital signal processor and circuit, digital rich/small transceivers can be realized. Since the foundation of this technology is based on the Nyquist theory, the operational frequency of the circuit has been limited by the Nyquist frequency (=1/2 of sampling clock frequency). As a result, the maximum operational RF frequency of existing digital RF technology was below 6 GHz. In this paper, a new direct digital RF technology that utilizes the higher-order Nyquist zones is introduced. This technology enables handling RF signal in beyond Nyquist frequency range which means over 6 GHz range. The results of fabricated 26/28 GHz-band transmitter/receiver are reviewed. Since the transceiver architecture with the proposed technologies does not require an RF local oscillator and up/down converters, it is suitable for microwave/millimeter-wave multi-antenna systems such as next generation satellite on-board digital beam forming and Beyond 5G fully digital Massive multiple-input multiple-output systems.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 5","pages":"1-10"},"PeriodicalIF":1.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141181997","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}

{"title":"Novel scheme for GPU-accelerated finite-difference time-domain simulation of electromagnetic wave interaction with magnetic plasma","authors":"Shimin He;Moran Liu;Ting Feng;Yiyun Wu;Xiang Wang;Chen Zhou;Ting Lan;Haiyin Qing","doi":"10.1029/2023RS007862","DOIUrl":"10.1029/2023RS007862","url":null,"abstract":"Based on graphical processing unit acceleration, a new method of finite-difference time-domain scheme is proposed to simulate the interaction between electromagnetic waves and magnetized plasma in two-dimensional conditions. In this study, transversely electric and transversely magnetic are computed in time to avoid matrix operations involving Lorentz equations of motion. Compared to Young's method, the new method reduces addition and multiplication by about 63% and 66%, respectively. The simulation results of ionospheric wave propagation show that the new method agrees well with Young's method and the calculation speed is improved significantly.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 5","pages":"1-16"},"PeriodicalIF":1.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141057515","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}