URSI Radio Science Bulletin最新文献_第9页

Become an individual member of URSI 成为URSI的个人成员

URSI Radio Science Bulletin Pub Date : 2020-12-01 DOI: 10.23919/URSIRSB.2020.9663146

引用次数: 0

Effect of mountain clutter on a VHF (206.5 MHz) wind profiler in the central Himalayas 喜马拉雅山脉中部山区杂波对甚高频（206.5MHz）风廓线仪的影响

URSI Radio Science Bulletin Pub Date : 2020-12-01 DOI: 10.23919/URSIRSB.2020.9663126

Samaresh Bhattacharjee;Manish Naja;Subra Ananthakrishnan

{"title":"Effect of mountain clutter on a VHF (206.5 MHz) wind profiler in the central Himalayas","authors":"Samaresh Bhattacharjee;Manish Naja;Subra Ananthakrishnan","doi":"10.23919/URSIRSB.2020.9663126","DOIUrl":"https://doi.org/10.23919/URSIRSB.2020.9663126","url":null,"abstract":"A modern, indigenously developed VHF ( 206.5 + 2.5 MHz) wind-profiler radar, operating in the Himalayan region, was installed at Aryabhatta Research Institute of Observational Sciences (ARIES) near Nainital, Uttarakhand (29.4N; 79.5E; 1793 m amsl) India. This profiler was named the Aries ST RADar (ASTRAD). The profiler was installed within a 30 m χ 30 m two-story building for better utilization of available space on a hilly terrain, surrounded by high-rise mountains. In an innovative way, 12 clusters of 49 elements were placed on the rooftop with the required precision in forming a quasi-circular aperture. Activation and integration of the clusters of the system progressed with extensive calibration of each individual transmitting/receiving module (TRM) connected with each antenna. During activation, the presence of a strong central patch in the Doppler-spectrum-like clutter, close to 0 Hz, was encountered. Based on experiments, it became clear that the reflected strength of the RF signal in the VHF band was significant due to the mountain terrain. A metal fence 3.5 m-4 m height was designed and installed at the perimeter of the rooftop to minimize the strength and to gain improvement in the detectability of the weak backscattered atmospheric signal. In this article, technical details of the system and design steps of the fence that led to overcoming the issue of clutter are summarized.","PeriodicalId":101270,"journal":{"name":"URSI Radio Science Bulletin","volume":"2020 375","pages":"33-39"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873543/9663119/09663126.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50329025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

President's address at the XXXIV URSI GASS 主席在URSI GASS第三十四次会议上的讲话

URSI Radio Science Bulletin Pub Date : 2020-12-01 DOI: 10.23919/URSIRSB.2020.9663139

Piergiorgio L. E. Uslenghi

引用次数: 0

Report on VERSIM 2020 VERSIM 2020报告

URSI Radio Science Bulletin Pub Date : 2020-12-01 DOI: 10.23919/URSIRSB.2020.9663141

Yoshiharu Omura

{"title":"Report on VERSIM 2020","authors":"Yoshiharu Omura","doi":"10.23919/URSIRSB.2020.9663141","DOIUrl":"https://doi.org/10.23919/URSIRSB.2020.9663141","url":null,"abstract":"The 9th VLF/ELF Remote Sensing of Ionospheres and Magnetospheres Workshop (VERSIM 2020) was successfully held as a virtual meeting during the week of 16–20 November 2020. The meeting had been rescheduled from the original meeting (23–27 March 2020 at the Uji Campus, Kyoto University, Japan), cancelled due to the COVID-19 pandemic. The VERSIM workshop aims to bring together scientists from all across the globe to present and discuss topics related to the excitation, propagation, and effects of electromagnetic waves in the ELF/VLF (300 Hz – 30 kHz) range. The VERSIM group was established as a joint URSI/IAGA work group in 1975. It has been the main scientific body to specifically focus on whistlers in the Earth's ionosphere and magnetosphere (whistler waves were one of the first electromagnetic signals detected by ground instruments, and gave important clues about the Earth's active space environment). The scope of this group has grown substantially over the years. It has grown particularly in recent years with the recognition that whistler-mode chorus and hiss waves play a particularly important role in shaping the dynamics of the Earth's high-energy radiation belts (particularly topical in light of the continuing successful operation of the Van Allen Probes and the Arase (ERG) spacecraft). Whistler waves are also known to be intimately involved in the magnetic reconnection process (which is currently very topical due to the launch of the MMS satellite) and solar flaring. In addition to the traditional VERSIM topics, results of recent space missions, such as Arase, MMS, and the Van Allen Probes, were presented.","PeriodicalId":101270,"journal":{"name":"URSI Radio Science Bulletin","volume":"2020 375","pages":"82-83"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873543/9663119/09663141.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50329075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Solution box: SOLBOX 21: Near-zero-index shells constructed by using dielectric rods 解决方案盒：SOLBOX 21：使用电介质棒构建的近零折射率外壳

URSI Radio Science Bulletin Pub Date : 2020-12-01 DOI: 10.23919/URSIRSB.2020.9663130

Özgür Ergül;Özgür Eriş;Özgür Ergül

{"title":"Solution box: SOLBOX 21: Near-zero-index shells constructed by using dielectric rods","authors":"Özgür Ergül;Özgür Eriş;Özgür Ergül","doi":"10.23919/URSIRSB.2020.9663130","DOIUrl":"https://doi.org/10.23919/URSIRSB.2020.9663130","url":null,"abstract":"In the previous issue of SOLBOX (SOLBOX-20), we discussed periodic arrangements of dielectric rods with interesting electromagnetic properties [1]. As computational simulations demonstrate, when material and geometric properties — such as the shapes, sizes, and periodicities of the rods — are properly selected, these arrangements can behave like homogeneous objects with near-zero refractive indices. In SOLBOX-20, this phenomenon was shown by constructing triangular prisms and investigating the refraction of electromagnetic beams through them. Using cylindrical rods with 3.75 mm radius, 17 mm center-to-center periodicity, and 8.8 relative permittivity (corresponding to alumina), near-zero refractive index values could effectively be obtained at 10.3 GHz. As also shown in the same numerical set, modifying the material of the rods, i.e., using 4.0 relative permittivity, dramatically changed the behaviors of the structures, which seemed to possess ordinary refractive index values just above unity. Specifically, without using an appropriate material, such an arrangement of rods did not provide near-zero-index (NZI) characteristics, while the effective relative permittivity induced in the environment simply corresponded to that of a diluted material in vacuum.","PeriodicalId":101270,"journal":{"name":"URSI Radio Science Bulletin","volume":"2020 375","pages":"45-50"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873543/9663119/09663130.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50329249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Editor's comments 编辑意见

URSI Radio Science Bulletin Pub Date : 2020-12-01 DOI: 10.23919/URSIRSB.2020.9663124

W. Ross Stone

引用次数: 0

History of ionospheric physics 电离层物理学史

URSI Radio Science Bulletin Pub Date : 2020-09-01 DOI: 10.23919/URSIRSB.2020.9523816

{"title":"History of ionospheric physics","authors":"","doi":"10.23919/URSIRSB.2020.9523816","DOIUrl":"https://doi.org/10.23919/URSIRSB.2020.9523816","url":null,"abstract":"Kristian Schlegel, past President of URSI, asked that the following open-access article on the history of ionospheric physics be brought to the attention of Radio Science Bulletin readers: A. Anduaga, “The Formation of Ionospheric Physics — Confluence of Traditions and Threads of Continuity,” History of Geo- and Space Sciences, 12, 1, 2021, pp. 57–75; available at https://doi.org/10.5194/hgss-12-57-2021. The following is the abstract from the article: This paper examines how ionospheric physics emerged as a research speciality in Britain, Germany, and the United States in the first four decades of the 20th century. It argues that the formation of this discipline can be viewed as the confluence of four deep-rooted traditions in which scientists and engineers transformed, from within, research areas connected to radio wave propagation and geomagnetism. These traditions include Cambridge school's mathematical physics, Göttingen's mathematical physics, laboratory-based experimental physics, and Humboldtian-style terrestrial physics. Although focused on ionospheric physics, the paper pursues the idea that a dynamic conception of scientific tradition will provide a new perspective for the study of geoscience history.","PeriodicalId":101270,"journal":{"name":"URSI Radio Science Bulletin","volume":"2020 374","pages":"88-88"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873543/9523795/09523816.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50415295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hertz and Marconi: A comparison between the apparatus of their landmark experiments 赫兹和马可尼：他们里程碑式实验装置的比较

URSI Radio Science Bulletin Pub Date : 2020-09-01 DOI: 10.23919/URSIRSB.2020.9523815

Stefano Maddio;Stefano Selleri

引用次数: 0

Women in radio science: Introduction by the associate editor 无线电科学中的女性：副主编介绍

URSI Radio Science Bulletin Pub Date : 2020-09-01 DOI: 10.23919/URSIRSB.2020.9523818

Asta Pellinen-Wannberg

引用次数: 0

Information for authors 作者信息

URSI Radio Science Bulletin Pub Date : 2020-09-01 DOI: 10.23919/URSIRSB.2020.9523825

引用次数: 0