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Anomalous behaviors of the VLF signals before earthquakes for VTX-Malda propagation path VLF信号在VTX-Malda传播路径下的震前异常行为
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6051047
S. Ray, S. Chakrabarti, A. Choudhury
{"title":"Anomalous behaviors of the VLF signals before earthquakes for VTX-Malda propagation path","authors":"S. Ray, S. Chakrabarti, A. Choudhury","doi":"10.1109/URSIGASS.2011.6051047","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6051047","url":null,"abstract":"We present the results of monitoring of four years (2005, 2007–09) of VLF signals collected in the Malda branch of ICSP, located in Malda, West Bengal and find the correlations, between the ionospheric activities and the earthquakes. Here we use that VLF signals which are transmitted from the VTX station (18.2 KHz). We first study the average signal throughout the year. We plot the so-called standardized calibration curve using the four years data. To establish the correlation between the ionospheric activities and the seismic events, we use the data of the year 2008 and we find that the deviations of the VLF day length (defined as the time difference between sunrise and sunset terminators) are correlated with the seismic event. We find that the highest deviation takes place one day prior to the seismic events. We also calculate the ‘D-layer preparation time’ (DLPT) and the ‘D-layer disappearance time’ (DLDT) for the data of 2008 and established the co-relation between the anomalous DLPT and DLDT with the seismic events. We find that the anomalous behaviour of the DLPT and DLDT are also correlated with the seismic events.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124448955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Propagation “over the horizon” of Saturn's radio lightning studied by three-dimensional ray tracing 通过三维射线追踪研究了土星射电闪电的“超越地平线”传播
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6051302
A.-L. Gautier, B. Cecconi, P. Zarka, G. Fischer
{"title":"Propagation “over the horizon” of Saturn's radio lightning studied by three-dimensional ray tracing","authors":"A.-L. Gautier, B. Cecconi, P. Zarka, G. Fischer","doi":"10.1109/URSIGASS.2011.6051302","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6051302","url":null,"abstract":"Saturn Electrostatic Discharges (SED] are radio signature of lightning flashes originating from Saturns cloud systems. Observations of SED show that the radio horizon is larger than the visible one, especially when Cassini is in Saturns morning side (“over the horizon” effect]. Moreover, both apparition and disappearance of bursts appear to be frequency-dependent. We built a 3D ray tracing code, which computes the path propagation of radio waves through a realistic model of Saturns ionosphere, where electron density varies with local time, and were able to reproduce the typical dynamic spectrum of observed “over the horizon” events.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126376437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Doherty power amplifiers in software radio systems 软件无线电系统中的多尔蒂功率放大器
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6050517
F. Ghannouchi, K. Rawat
{"title":"Doherty power amplifiers in software radio systems","authors":"F. Ghannouchi, K. Rawat","doi":"10.1109/URSIGASS.2011.6050517","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6050517","url":null,"abstract":"Power amplification in software defined radio needs reconfigurabilty as well as optimum performance in terms of linearity and efficiency to handle different modulation standards (and hence carrier and modulation bandwidth). Since digital predistortion is now widely accepted as highly suitable solutions for linearization in a reconfigurable perspective. Hence, this technique in conjunction with multi-band Doherty power amplifiers finds a potential solution for reconfigurable-multi-band software defined radio transmitter. This paper demonstrates the current state-of art for such transmitters, including a brief discussion about the available design methodology for the dual-band Doherty power amplifier.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126225871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Advances in two-dimensional and three-dimensional laser imagery modeling 二维和三维激光成像建模研究进展
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6050368
G. Berginc
{"title":"Advances in two-dimensional and three-dimensional laser imagery modeling","authors":"G. Berginc","doi":"10.1109/URSIGASS.2011.6050368","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6050368","url":null,"abstract":"Laser radar (Ladar) technology has enjoyed significant advances over the past decade. Novel focal plane areas, compact laser illuminators and advanced signal processing have enabled the construction of low power 2-D and 3-D laser imagery systems. The applications of such systems range from surveillance, targeting and weapons guidance to target identification. This paper deals with modeling of new optical non-conventional imaging with laser systems. In this paper, we present the simulation of the 3D ladar sensor including physics based modeling of laser backscattering from complex rough targets, reflectance modeling of porous occluders, development of 3D scenes and reconstruction algorithms for identification. This paper addresses the utility of physics based scene simulation in support of tomography algorithms for reconstructing optical three-dimensional scenes. This includes a review of the physics and phenomenology that can be modeled and examples of scene.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126404312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Computation of the effects of solar phenomena on Global Ionospheric Weather using wave guide mode theory of VLF propagation 利用VLF传播的波导模式理论计算太阳现象对全球电离层天气的影响
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6051009
T. Basak, S. Chakrabarti, S. Pal
{"title":"Computation of the effects of solar phenomena on Global Ionospheric Weather using wave guide mode theory of VLF propagation","authors":"T. Basak, S. Chakrabarti, S. Pal","doi":"10.1109/URSIGASS.2011.6051009","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6051009","url":null,"abstract":"The sub-ionospheric VLF signal strength varies significantly with place and time. The solar eclipse and regular solar terminator motion effects on the Global Ionospheric Weather (GIW) and hence the VLF propagation. It has been simulated considering wave guide mode theory of VLF radio signal propagation along various transmitter to receiver great circular paths. Using Long Wave Propagation Capability code, the mode theoretical results are obtained. To estimate the ionospheric weather changes by VLF technique during a total solar eclipse, a three dimensional model of disk obscuration & its ionospheric consequences has been constructed.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128127460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Principles of Dynasonde Navigator 王朝导航仪原理
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6050895
M. Rietveld, N. Zabotin
{"title":"Principles of Dynasonde Navigator","authors":"M. Rietveld, N. Zabotin","doi":"10.1109/URSIGASS.2011.6050895","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6050895","url":null,"abstract":"Dynasonde is an ideology of precision ionospheric radio sounding based on rigorously taking into account phase characteristics of a radio echo. Unique products of phase ionosondes intended for various Space Weather-related applications include: echo recognition and noise discrimination, echo classification into traces, scaling of standard ionospheric parameters, 3-D plasma density inversion (NeXtYZ) including true vertical profile with error bars, small-scale irregularity diagnostics, and vector velocities, all obtained directly and autonomously from ionogram data. Our report describes details of implementation of Dynasonde principles in operation of the web portal Dynasonde Navigator (http://dynserv.eiscat.uit.no) hosted by EISCAT.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128154966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Throughput of optimal and suboptimal low-power IR-UWB coherent receivers for wireless body-area-networks (WBANs) 无线体域网络(wban)中最优和次最优低功率IR-UWB相干接收机的吞吐量
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6051323
H. Shaban, M. A. El-Nasr, R. Buehrer
{"title":"Throughput of optimal and suboptimal low-power IR-UWB coherent receivers for wireless body-area-networks (WBANs)","authors":"H. Shaban, M. A. El-Nasr, R. Buehrer","doi":"10.1109/URSIGASS.2011.6051323","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6051323","url":null,"abstract":"Impulse radio ultra wide band (IR-UWB) systems have the potential for low-power consumption as well as high data-rates over short distances. This makes them an attractive candidate for emerging wireless body-area-network (BAN) applications. In this paper, we investigate the performance of low-power suboptimal real sinusoidal-template based detectors for M-ary pulse-amplitude-modulation (PAM) and M-ary equally-correlated pulse-position-modulation M-ary (EC-PPM) modulation techniques in multipath channels. Furthermore, we provide numerical results in the UWB-based IEEE 802.15.6a channels, and evaluate the corresponding attainable throughput.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128156828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
Pathfinders and precursors for the SKA SKA的探路者和前体
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6051202
J. Cordes
{"title":"Pathfinders and precursors for the SKA","authors":"J. Cordes","doi":"10.1109/URSIGASS.2011.6051202","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6051202","url":null,"abstract":"I will discuss pathfinding activities in science, technology development and cyber-infrastructure that are relevant to the Square Kilometre Array. Technology development includes work on dish antennas, wideband dipole arrays, wideband feed antennas, and widefield phased array feeds. Science applications include time-domain exploration, deep continuum imaging, and high-rate surveys. The implied data volumes are growing exponentially and need to be matched with data management and mining systems.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125483939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Modular planar antenna at X-band for satellite communications 用于卫星通信的x波段模块化平面天线
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6050477
J. Inclán-Alonso, A. Garcia-Aguilar, L. Vigil-Herrero, J. Fernández-González, J. Sanmartin-Jara, M. Sierra-Pérez
{"title":"Modular planar antenna at X-band for satellite communications","authors":"J. Inclán-Alonso, A. Garcia-Aguilar, L. Vigil-Herrero, J. Fernández-González, J. Sanmartin-Jara, M. Sierra-Pérez","doi":"10.1109/URSIGASS.2011.6050477","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6050477","url":null,"abstract":"An antenna which has been conceived as a portable system for satellite communications based on the recommendations ITU-R S.580–6 [1] and ITU-R S.465–5 [2] for small antennas, i.e., with a diameter lower than 50 wavelengths, is introduced. It is a planar and a compact structure with a size of 40×40×2 cm. The antenna is formed by an array of 256 printed elements covering a large bandwidth (14.7%) at X-Band. The specification includes transmission (Tx) and reception (Rx) bands simultaneously. The printed antenna has a radiation pattern with a 3dB beamwidth of 5°, over a 31dBi gain, and a dual and an interchangeable circular polarization.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125666471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Timing of optical pulsars with two high time resolution photometers at Asiago and NTT 在阿齐亚戈和NTT用两个高时间分辨率光度计测量脉冲星的时间
2011 XXXth URSI General Assembly and Scientific Symposium Pub Date : 2011-10-20 DOI: 10.1109/URSIGASS.2011.6050331
C. Barbieri, G. Naletto, A. Shearer, L. Zampieri, C. Germanà, S. Gradari, G. Codogno
{"title":"Timing of optical pulsars with two high time resolution photometers at Asiago and NTT","authors":"C. Barbieri, G. Naletto, A. Shearer, L. Zampieri, C. Germanà, S. Gradari, G. Codogno","doi":"10.1109/URSIGASS.2011.6050331","DOIUrl":"https://doi.org/10.1109/URSIGASS.2011.6050331","url":null,"abstract":"We have built two single photon very high speed photometers (Aqueye for the Asiago 1.8m telescope and Iqueye for the 3.5m ESO NTT) as prototypes of a ‘quantum’ photometer for the European Extremely Large Telescope (E‐ELT) The two photometers are the most accurate ‘time machines’ available to optical astronomy. Under the control of a GPS receiver and a Rubidium clock, the arrival time of each detected photon is referenced to UTC with a precision better than 500 picoseconds, continuously for hours of data acquisition. Light curves for three optical pulsars (Crab, B0540‐69, Vela) will be reported. Results from simultaneous observations of the Crab pulsar with the Jodrell Bank RadioTelescope will also be reported.","PeriodicalId":325870,"journal":{"name":"2011 XXXth URSI General Assembly and Scientific Symposium","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125843836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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