2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)最新文献

{"title":"Redundant and non-imaging calibration of the Precision Array For Probing The Epoch Of Reionization (PAPER)","authors":"J. Aguirre, A. Parsons, R. Bradley, C. Carilli, D. DeBoer, Z. Ali, Adrian Liu, D. Jacobs, David F. Moore, J. Pober, I. Stefan","doi":"10.1109/USNC-URSI-NRSM.2014.6928120","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928120","url":null,"abstract":"Summary form only given. The Precision Array for Probing the Epoch of Reionization (PAPER) is a focused experiment aimed at detecting the spatial power spectrum of neutral hydrogen emission during the Epoch of Reionization (EoR). PAPER is an interferometer operating from 100 - 200 MHz at the site of the future Square Kilometre Array (SKA) site in South Africa. The PAPER antennas measure linear polarization and the correlator produces full-Stokes output. PAPER currently has 64 antennas and has just completed a 141-day science integration. An expansion to 128 antennas and another long observing campaign will be complete in late 2013. In order to achieve maximum sensitivity to particular modes of the power spectrum, PAPER currently employs a highly redundant array configuration. This configuration samples the uv-plane extremely poorly by design, is not therefore particularly suited to standard self-calibration techniques. It has been known for many years (e.g Noordam & de Bruyn 1982), however, that instantaneous baseline redundancy allows a robust, fast and simple method for achieving relative gain and phase delay calibration between antennas. We consider the accuracy and long-term stability of the resulting calibration achieved with PAPER for Stokes I. Calibrating the leakage terms for the remaining Stokes parameters using only redundancy has proved challenging. We present a per-baseline method, appropriate for a non-imaging approach, to obtain the relative x-y linear polarization delay and characterize remaining leakage terms. We finally demonstrate how the decoupling of the individual baselines' relative calibration from the determination of a sky model is used in conjunction with a delay-space CLEANing of the visibility to spectrum (Parsons & Backer 2009) to achieve high-dynamic-range suppression of smooth-spectrum foreground emission. This approach minimizes the effect of calibration errors on the estimation of the final EoR power spectrum.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126690935","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}

{"title":"Calculations of 4278 Å artificial auroral airglow emissions resulting from powerful HF radio transmissions","authors":"C. Fallen, B. Watkins","doi":"10.1109/USNC-URSI-NRSM.2014.6928080","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928080","url":null,"abstract":"Powerful HF electromagnetic waves transmitted into the ionosphere from the High-frequency Active Auroral Research Program (HAARP) facility in Alaska and the European Incoherent Scatter Scientific Association (EISCAT) facility in Norway have induced artificial aurora with ground-measurable 4278 Å wavelength emissions (B. Gustavsson et al., Ann. Geophys., 23, 1747-1754, 2005; T. B. Pedersen et al., Geophys. Res. Lett. 37, 2, L02106, 2010). This artificial “blue-line” emission can result from the electronic transition of an N2+(1N) ion to its ground state. The two main sources of N2+(1N) ions in the F region are photoionization and electron-impact ionization of N2 molecules. Experimental and theoretical evidence suggests that impact ionization of N2 molecules by electrons accelerated by wave-plasma interactions to energies exceeding 18 eV is responsible at least in part for artificial 4278 Å wavelength emissions observed during ionosphere radio modification experiments at HAARP and EISCAT (H. C. Carlson et al., J. Atmos. Solar Terr. Phys., 44, 12, 1089-1100, 1982; A. V. Gurevich et al., J. Atmos. Terr. Phys., 47, 11, 1057-1070, 1985).","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126082734","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}

{"title":"Sweeping Impedance Probe new techniques for ionospheric plasma diagnostics","authors":"Julio Martin-Hidalgo, C. Swenson, Daniel Farr","doi":"10.1109/USNC-URSI-NRSM.2014.6928085","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928085","url":null,"abstract":"The impedance of a probe immersed in ionospheric plasma at radio frequencies is an important technique for determining absolute electron density. Building on 50 years of history in developing and flying RF probes for plasma diagnostics at Utah State, a new SIP (Sweeping Impedance Probe) design has been completed which will obtain qualitative improvement over previous instruments in terms of accuracy and sweep rate. The new technique is based on sequential measurements to improve the error correction, and requiring simple components by using DC as intermediate frequency. This instrument will provide a continuous measurement of the plasma impedance magnitude and phase with an expected accuracy of 1% and 1 degree respectively over the 1 to 20 MHz range.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127830103","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}

{"title":"Inferring 2D spatio-temporal properties of irregularities from a closely-spaced sub-auroral scintillation array","authors":"S. Datta‐Barua, G. Bust, Yang Su, K. Deshpande","doi":"10.1109/USNC-URSI-NRSM.2014.6928061","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928061","url":null,"abstract":"Summary form only given. Auroral zone irregularities affect a broad swath of radio frequencies through rapid phase fluctuations in the received signal experienced by the receiver, known as scintillation. Scintillation can lead to loss of HF communications and L-band satellite-based navigation through receiver loss of lock. For this reason, the ability to quantify the severity and predict the occurrence of high-latitude scintillation continues to be a major goal in upper atmospheric science and applied research. Some scintillation models characterize scintillations by phase and/or amplitude variance indices sigma-phi and S4, while others parameterize the power spectral density of the phase scintillations observed, but these apply for single station observations. Often it is useful for applications as well as scientifically to understand how the scintillation parameters measured at one location may be correlated with scintillation occurrence and severity at another nearby location. In other words, we would like to know the spatial and temporal variation of the phase fluctuations themselves. Since the fluctuations at Global Navigation Satellite System (GNSS) L-band corresponds to scale sizes on the order of 100 m, it is useful to know about spatial variations at the 100 m to 1 km scale range. Advances in GNSS scintillation monitoring technologies and reduction in instrumentation cost have enabled the ability to establish arrays of ground-based arrays with km and sub-km baselines in two dimensions. In this effort, we present our continuing analysis of scintillation observations made with a 2-dimensional array of sub-km spaced receivers in the northern auroral zone. Previous estimates of the phase fluctuation velocity with respect to the ground, as observed by the array, are refined by accounting for relative Global Positioning System (GPS) signal raypath motion, by projecting the observable direction onto the locally horizontal plane, and by appropriate weighting of the observables in the estimation equation. These are compared with auxiliary data from magnetometers, SuperDARN and all-sky image data sets. We conduct spectral analyses of the fluctuations at each of the array receivers. For cases where the \"frozen field\" approximation is valid, and we have a wavenumber spectrum along the direction of the velocity, the Rino and Fremouw (J. Atmospheric and Terrestrial Physics, vol. 39, p. 859-868, 1977) equation relating observed phase to statistical properties of the irregularities, will be used to infer the spatial spectrum, altitude and thickness of the irregularities. In addition, the ground 2D drift velocity can then be projected to the irregularity altitude providing the drift speeds at ionospheric heights.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128794928","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}

{"title":"Time-domain terahertz imaging and spectroscopy of x-ray blocking and scattering coatings","authors":"N. Burford, M. El-Shenawee","doi":"10.1109/USNC-URSI-NRSM.2014.6927949","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6927949","url":null,"abstract":"The terahertz (THz) band of the electromagnetic spectrum is the gap between the microwave/millimeter wave band and the far infrared band. This band has been historically defined to be around 0.1 to 10 THz, due to the long-standing difficulties in efficient generation and detection of these frequencies. Only recently have efficient and practical commercial THz systems become available. Imaging with THz waves offers several unique advantages. THz waves can penetrate several millimeters into non-conducting materials. This allows for imaging of features that are covered in an optically opaque coating. Since THz waves have a shorter wavelength than microwaves, they are able to resolve smaller features. Unlike the x-ray imaging that is often associated with imaging into materials, the low photon energy of THz waves cannot ionize materials. This negates the risk of irreversible material damage inherent with x-ray imaging.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127010662","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}

{"title":"Multi-instrument ionospheric tomography in Scandinavia with Bayesian statistical inversion and correlation priors","authors":"J. Norberg, J. Vierinen, L. Roininen, O. Amm, M. Lehtinen","doi":"10.1109/USNC-URSI-NRSM.2014.6928076","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928076","url":null,"abstract":"We present a novel algorithm for ionospheric tomography and the latest results obtained with it. Ionospheric tomography is mathematically a sparse limited-angle tomography problem and therefore severely ill-posed. This means that to obtain reasonable reconstructions the problem needs a strong regularisation. In ionospheric tomography the regularisation is often implemented with a limited set of base functions, Tikhonov regularisation, initial profiles for iterative methods, or with a different combinations of these schemes. These methods have been shown to produce satisfactory reconstructions, but the role of the regularisation and how much the chosen method actually constraints the possible outcomes is not always clear. Our tomography scheme is implemented in the Bayesian statistical framework (Markkanen et al. Ann. Geophys., vol. 13, pp. 1277-1287, 1995). In Bayesian inference the regularisation is given as an a priori distribution. The a priori distribution contains the information about the unknown parameters before the measurements. The second step is to build a likelihood function for the unknown parameters, given the observed measurements. By combining the likelihood with the prior density function, we obtain the a posteriori distribution, from where we can obtain the estimate with the highest probability, based on the information in our disposal. Here we give the a priori distribution with the novel correlation priors (Roininen et al. Inverse Probl. Imag., vol. 5, issue 2, pp. 611-647, 2011). Essentially the correlation priors are Gaussian Markov random fields, wherein we can state the physical assumptions of the ionosphere in an interpretable manner. With this implementation we get a very thorough understanding of what is the role of the regularising a priori distribution. On addition to that, the statistical framework also gives a very natural way to combine different ionospheric measurements. Therefore we can use measurements from Low Earth Orbit (LEO) and Global Positioning System (GPS) satellites as well as ground based measurements in the same model. Starting from 2011, as a part of TomoScand project, Finnish Meteorological Institute has been installing a new receiver network for LEO beacon satellites. At the moment, together with the receiver network of Sodankyla Geophysical Observatory, we collect data from 11 receivers stations. The northern most receiver located in Svalbard and southern most in Estonia. We also collect data from 86 GPS receiver stations provided by Finnish company Geotrim. We present the latest results with the new network and algorithm in a 2-dimensional case, however, the goal in the near future is to extend the model to a 3-dimensional case to cover over Scandinavia.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130427009","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}

{"title":"Wave-kinetic simulations of lower-hybrid turbulence driven by velocity ring instabilities","authors":"C. Crabtree, G. Ganguli, M. Mithaiwala, L. Rudakov","doi":"10.1109/USNC-URSI-NRSM.2014.6928089","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928089","url":null,"abstract":"Summary form only given. We develop numerical solutions to the wave-kinetic equation in a periodic box, including the effects of nonlinear (NL) scattering of Lower-hybrid waves, which gives the evolution of the wave-spectra in wavenumber space. Simultaneously we solve the particle diffusion equation of both the background plasma particles and the ring ions, due to both linear and nonlinear Landau resonances. At early times when the ring ions are cold, an electrostatic beam mode is excited, while a kinetic mode is stable. As the instability progresses the ring ions heat, the beam mode is stabilized, and the kinetic mode destabilizes. When the amplitude of the waves becomes sufficient the lower-hybrid waves are scattered (by either nearly unmagnetized ions or magnetized electrons) into electromagnetic magnetosonic waves [Ganguli et al 2010]. The effect of NL scattering is to limit the amplitude of the waves, slowing down the quasilinear relaxation time and ultimately allowing more energy from the ring to be liberated into waves [Mithaiwala et al., 2011]. The effects of convection out of the instability region are modeled, additionally limiting the amplitude of the waves, allowing further energy to be liberated from the ring [Scales et al., 2012]. Results are compared to recent 3D PIC simulations [Winske and Duaghton 2012], and the potential implications for the radiation belts are discussed [Crabtree et al., 2012].","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130825575","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}

{"title":"Antenna location effects on the capacity of MIMO DSRC channels","authors":"N. Adhikari, S. Noghanian","doi":"10.1109/USNC-URSI-NRSM.2014.6928032","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928032","url":null,"abstract":"Summary form only given. Dedicated Short Range Communication (DSRC) [1], an automotive communication protocol, is popular for its potential application like Lane Changing Warning (LCW), Forward Collision Warning (FCW) in ensuring traffic safety and reducing traffic accidents. The major challenge in developing such application to provide a 360 degrees view of traffic status is to overcome the hurdle provided by the obstacles in form of buildings (in intersection), heavy vehicles (in case of overtaking), generally categorized as Non-Line-of-Sight (NLOS) scenarios [2]. In this work, we have used a vehicle as an obstacle between two other vehicles (at the transmitting and receiving ends). Antennas were placed at various locations on the vehicles' bodies. A total of 15 transmitters and receivers were spread out on the rear, center and front of two vehicles. The two vehicles were separated by two different distances: 10 meters and 15 meters, and the obstacle vehicle was positioned at the center, between these vehicles. This multiple antenna system was studied at two different locations. One location was in the area of College of Engineering and Mines, University of North Dakota, and the other was in the area around Walmart in Grand Forks, ND. Commercial simulation software, Wireless InSite® from Remcom Inc. [3], was utilized. Initially, the response of each receiver with respect to each transmitter was analyzed depending on the received power. By adopting the concept of Multiple Input and Multiple Output (MIMO) [4-5], different combination of transmitters and receivers were used to evaluate the channel capacity of a vehicle-to-vehicle (V2V) communication system in respect to antenna position [6]. These NLOS cases were compared to Line-of-Sight (LOS) cases (studied previously in [6]) when the obstacle vehicle was removed from the transmitting and receiving vehicle. The obtained capacities values were then compared with the capacity for a MIMO Rayleigh fading channel [7]. Furthermore, the impact of inclusion of phase of the received signal on channel capacity equation was studied.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128141772","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}

{"title":"A phaseless near-field measurement technique for antennas with an internal source","authors":"T. Brockett, Y. Rahmat-Samii","doi":"10.1109/USNC-URSI-NRSM.2014.6927944","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6927944","url":null,"abstract":"Summary form only given. Modern wireless devices are increasingly becoming completely integrated, where all components from the source to the antenna are included in the overall design. From a design and manufacturing standpoint this is quite advantageous, however, from a testing and measurement standpoint, verifying performance can be complicated, especially when characterizing the antenna. In conventional antenna measurements, an input signal is applied directly to the input of the antenna where its radiation is measured using a measuring probe at a certain far field distance from the antenna. This input signal is usually referenced using a network analyzer or similar transceiver system to determine the amplitude and phase captured by the measuring probe. In conventional near-field measurements, this referenced signal is required because both amplitude and phase must be measured to allow calculation of the far-field radiation pattern from the measured near fields. For antennas that feature their own internal source, the input signal must have some way to be referenced. Unless the device designer specifically adds a way to do so, this is usually not possible. For existing antenna measurement chambers and ranges, this adds complication to the configuration to measure the antenna, especially for near-field ranges where modification of existing chambers may not be possible. Thus, for measurements of an antenna with an internal source, one cannot use the measurement configuration in the conventional way. This presentation will introduce a solution using a unique measurement configuration and phaseless measurement techniques. The configuration includes terminating the transmitter on the network analyzer and using it purely as a receiver, measuring both amplitude and phase of the antenna using the reference signal from the network analyzer instead of a reference signal from the antenna's internal source. In this configuration, the measured amplitude and phase value is the relative value in relation to the integrated device's source. In theory, this is still valid for near-field measurement because relative field values are required to calculate the far-field. In reality, however, the lack of synchronicity between the network analyzer's source and the device's internal source causes stability issues (drift) with the measured phase. This renders the measured phase unusable for the near-field to far-field transformation. In contrast, the relative amplitude can be used as long as the internal source power is stable. This allows for the use of phaseless near-field measurement techniques (i.e. phase retrieval) to determine the near-field phase that is required for the near-field to far-field transformation. Representative measured results are shown to demonstrate the utility of this techniques.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128188288","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}

{"title":"A survey of active galactic nuclei jets with the RadioAstron space VLBI mission","authors":"M. Lister","doi":"10.1109/USNC-URSI-NRSM.2014.6928128","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2014.6928128","url":null,"abstract":"Launched in 2011, the Russian RadioAstron orbiting radio telescope gives the highest angular resolution ever attained in astronomy. By observing in concert with large Earth-based telescopes, it has successfully achieved a record angular resolution of 30 microarcseconds, and is currently being used to survey a large set of radio jets associated with active galactic nuclei (AGN) at 1.3, 6, and 18 cm wavelengths. A major goal of its AGN key science program is to directly measure the sizes of the synchrotron emission regions in AGN jets, near the central black holes where they are formed. Earth-based VLBI has not yet been able to probe this regime. RadioAstron is thus providing new important details on the geometry, emission mechanisms, and amount of relativistic beaming in these powerful outflows. We present preliminary results from the RadioAstron AGN survey, demonstrating that very high flow Lorentz factors (> 100) or coherent emission mechanisms may be needed to explain the extreme compactness of the radio emission. We also compare our findings to those from the ground-based MOJAVE VLBA survey, which has found Lorentz factors ranging up to only ~ 40 in a large sample of the brightest known AGN jets.","PeriodicalId":277196,"journal":{"name":"2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132094572","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}