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Sample records for enhanced uwb radio

  1. UWB EMI To Aircraft Radios: Field Evaluation on Operational Commercial Transport Airplanes. Volume 1

    NASA Technical Reports Server (NTRS)

    Oria, A. J. (Editor); Ely, Jay J.; Martin, Warren L.; Shaver, Timothy W.; Fuller, Gerald L.; Zimmerman, John; Fuschino, Robert L.; Larsen, William E.

    2005-01-01

    Ultrawideband (UWB) transmitters may soon be integrated into a wide variety of portable electronic devices (PEDs) that passengers routinely carry on board commercial airplanes. Airlines and the FAA will have difficulty controlling passenger use of UWB transmitters during flights with current airline policies and existing wireless product standards. The aeronautical community is concerned as to whether evolving FCC UWB rules are adequate to protect legacy and emerging aeronautical radio systems from electromagnetic interference (EMI) from emerging UWB products. To address these concerns, the NASA Office of Space Communications and Chief Spectrum Managers assembled a multidisciplinary team from NASA LaRC, NASA JPL, NASA ARC, FAA, United Airlines, Sky West Airlines, and Eagles Wings Inc. to carry out a comprehensive series of tests aimed at determining the nature and extent of any EMI to aeronautical communication and navigation systems from UWB devices meeting FCCapproved and proposed levels for unlicensed handheld transmitters.

  2. A DS-UWB Cognitive Radio System Based on Bridge Function Smart Codes

    NASA Astrophysics Data System (ADS)

    Xu, Yafei; Hong, Sheng; Zhao, Guodong; Zhang, Fengyuan; di, Jinshan; Zhang, Qishan

    This paper proposes a direct-sequence UWB Gaussian pulse of cognitive radio systems based on bridge function smart sequence matrix and the Gaussian pulse. As the system uses the spreading sequence code, that is the bridge function smart code sequence, the zero correlation zones (ZCZs) which the bridge function sequences' auto-correlation functions had, could reduce multipath fading of the pulse interference. The Modulated channel signal was sent into the IEEE 802.15.3a UWB channel. We analysis the ZCZs's inhibition to the interference multipath interference (MPI), as one of the main system sources interferences. The simulation in SIMULINK/MATLAB is described in detail. The result shows the system has better performance by comparison with that employing Walsh sequence square matrix, and it was verified by the formula in principle.

  3. Enhanced Ultra-Wideband (UWB) Circular Monopole Antenna with Electromagnetic Band Gap (EBG) Surface and Director

    DTIC Science & Technology

    2014-08-01

    concept of enhanced UWB monopole antenna ............................................................5 Fig. 7 Conventional mushroom EBG surface (left) vs...space (red squares) and the antenna over a single-layer mushroom EBG (blue diamonds...or coherent, signal that adds to the antenna radiation. One of the common EBG designs, known as mushroom design, is based on a periodic array of

  4. Hybrid UWB and WiMAX radio-over-multi-mode fibre for in-building optical networks

    NASA Astrophysics Data System (ADS)

    Perez, J.; Llorente, R.

    2014-01-01

    In this paper the use of hybrid WiMedia-defined ultra-wideband (UWB) and IEEE 802.16d WiMAX radio-over-fibre is proposed and experimentally demonstrated for multi-mode based in-building optical networks with the advantage of great immunity to optical transmission impairments. In the proposed approach, spectral coexistence of both signals must be achieved with negligible mutual interference. The experimental study performed addressed an indoor configuration with 50 μm multi-mode fibres (MMF) and 850 nm vertical-cavity surface-emitting laser (VCSEL) transmitters. The results indicate that the impact of the wireless convergence in radio-over-multi-mode fibre (RoMMF) is significant for UWB transmissions, mainly due to MMF dispersion and electrooptical (EO) devices with limited bandwidth. On the other hand, WiMAX transmission is feasible for a 300 m MMF and 30 m wireless link in the presence of UWB, with -31 dBm WiMAX EVM.

  5. Attenuation characteristic of UWB signals propagation in free space

    NASA Astrophysics Data System (ADS)

    Li, Meng; Huang, Zhonghua

    2016-10-01

    Researching attenuation characteristic of UWB signals propagation in free-space is necessary for ultra-wideband (UWB) radio fuze optimized design. Research attenuation characteristic of UWB signals propagation in free space can be achieved by learning attenuation characteristic of radio waves propagation in free-space and UWB signal power spectral density. 50ps, 100ps and 200ps of pulse width UWB fuze transmission narrow pulse signal propagation in free-space are simulated and analyzed. The attenuation of UWB signals at 3m, 6m and 9m are contrasted. The simulation, analysis and contrast is theoretical basis of UWB radio fuze optimized design.

  6. 4 Gbps impulse radio (IR) ultra-wideband (UWB) transmission over 100 meters multi mode fiber with 4 meters wireless transmission.

    PubMed

    Jensen, Jesper Bevensee; Rodes, Roberto; Caballero, Antonio; Yu, Xianbin; Gibbon, Timothy Braidwood; Monroy, Idelfonso Tafur

    2009-09-14

    We present experimental demonstrations of in-building impulse radio (IR) ultra-wideband (UWB) link consisting of 100 m multi mode fiber (MMF) and 4 m wireless transmission at a record 4 Gbps, and a record 8 m wireless transmission at 2.5 Gbps. A directly modulated vertical cavity surface emitting laser (VCSEL) was used for the generation of the optical signal. 8 m at 2.5 Gbps corresponds to a bit rate--distance product of 20; the highest yet reported for wireless IR-UWB transmission.

  7. Toward a highly accurate ambulatory system for clinical gait analysis via UWB radios.

    PubMed

    Shaban, Heba A; Abou el-Nasr, Mohamad; Buehrer, R Michael

    2010-03-01

    In this paper, we propose and investigate a low-cost and low-complexity wireless ambulatory human locomotion tracking system that provides a high ranging accuracy (intersensor distance) suitable for the assessment of clinical gait analysis using wearable ultra wideband (UWB) transceivers. The system design and transceiver performance are presented in additive-white-gaussian noise and realistic channels, using industry accepted channel models for body area networks. The proposed system is theoretically capable of providing a ranging accuracy of 0.11 cm error at distances equivalent to interarker distances, at an 18 dB SNR in realistic on-body UWB channels. Based on real measurements, it provides the target ranging accuracy at an SNR = 20 dB. The achievable accuracy is ten times better than the accuracy reported in the literature for the intermarker-distance measurement. This makes it suitable for use in clinical gait analysis, and for the characterization and assessment of unstable mobility diseases, such as Parkinson's disease.

  8. UWB Tracking Software Development

    NASA Technical Reports Server (NTRS)

    Gross, Julia; Arndt, Dickey; Ngo, Phong; Phan, Chau; Dusl, John; Ni, Jianjun; Rafford, Melinda

    2006-01-01

    An Ultra-Wideband (UWB) two-cluster Angle of Arrival (AOA) tracking prototype system is currently being developed and tested at NASA Johnson Space Center for space exploration applications. This talk discusses the software development efforts for this UWB two-cluster AOA tracking system. The role the software plays in this system is to take waveform data from two UWB radio receivers as an input, feed this input into an AOA tracking algorithm, and generate the target position as an output. The architecture of the software (Input/Output Interface and Algorithm Core) will be introduced in this talk. The development of this software has three phases. In Phase I, the software is mostly Matlab driven and calls C++ socket functions to provide the communication links to the radios. This is beneficial in the early stage when it is necessary to frequently test changes in the algorithm. Phase II of the development is to have the software mostly C++ driven and call a Matlab function for the AOA tracking algorithm. This is beneficial in order to send the tracking results to other systems and also to improve the tracking update rate of the system. The third phase is part of future work and is to have the software completely C++ driven with a graphics user interface. This software design enables the fine resolution tracking of the UWB two-cluster AOA tracking system.

  9. Meander-line-based inhomogeneous anisotropic artificial material for gain enhancement of UWB Vivaldi antenna

    NASA Astrophysics Data System (ADS)

    Pandey, Gaurav Kumar; Singh, Hari Shankar; Meshram, Manoj Kumar

    2016-02-01

    An inhomogeneous anisotropic (IA) artificial material (AM) is proposed having epsilon-near-zero (ENZ) characteristics and effective refractive index >1, simultaneously, in the same direction. Further, the proposed IA-AM is utilized for the gain enhancement of Vivaldi antenna for ultra-wideband (UWB) applications. The IA-AM consists of two types of compact meandered line-based anisotropic artificial material with ENZ characteristics in two adjacent narrow bands of 5.5-8.5 and 8-11.5 GHz. However, the non-resonant behavior of the artificial material in other direction appears with high refractive index property in broadband region. The combination of both the unit cells with broadband ENZ and high refractive index property is used to improve the gain of the Vivaldi antenna in broadband. The proposed IA-AM-loaded Vivaldi antenna exhibits a gain enhancement of up to 2 dBi compared to the original antenna in the operating frequency band of 3.1-12 GHz with | S 11| < -10 dB. The proposed antenna shows nearly stable unidirectional radiation patterns with high directivity and nearly flat group delay.

  10. UWB communication receiver feedback loop

    DOEpatents

    Spiridon, Alex; Benzel, Dave; Dowla, Farid U.; Nekoogar, Faranak; Rosenbury, Erwin T.

    2007-12-04

    A novel technique and structure that maximizes the extraction of information from reference pulses for UWB-TR receivers is introduced. The scheme efficiently processes an incoming signal to suppress different types of UWB as well as non-UWB interference prior to signal detection. Such a method and system adds a feedback loop mechanism to enhance the signal-to-noise ratio of reference pulses in a conventional TR receiver. Moreover, sampling the second order statistical function such as, for example, the autocorrelation function (ACF) of the received signal and matching it to the ACF samples of the original pulses for each transmitted bit provides a more robust UWB communications method and system in the presence of channel distortions.

  11. UWB transmitter

    SciTech Connect

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-01-15

    An ultra-wideband (UWB) dual impulse transmitter is made up of a trigger edge selection circuit actuated by a single trigger input pulse; a first step recovery diode (SRD) based pulser connected to the trigger edge selection circuit to generate a first impulse output; and a second step recovery diode (SRD) based pulser connected to the trigger edge selection circuit in parallel to the first pulser to generate a second impulse output having a selected delay from the first impulse output.

  12. Performance Evaluation of MIMO-UWB Systems Using Measured Propagation Data and Proposal of Timing Control Scheme in LOS Environments

    NASA Astrophysics Data System (ADS)

    Takanashi, Masaki; Nishimura, Toshihiko; Ogawa, Yasutaka; Ohgane, Takeo

    Ultrawide-band impulse radio (UWB-IR) technology and multiple-input multiple-output (MIMO) systems have attracted interest regarding their use in next-generation high-speed radio communication. We have studied the use of MIMO ultrawide-band (MIMO-UWB) systems to enable higher-speed radio communication. We used frequency-domain equalization based on the minimum mean square error criterion (MMSE-FDE) to reduce intersymbol interference (ISI) and co-channel interference (CCI) in MIMO-UWB systems. Because UWB systems are expected to be used for short-range wireless communication, MIMO-UWB systems will usually operate in line-of-sight (LOS) environments and direct waves will be received at the receiver side. Direct waves have high power and cause high correlations between antennas in such environments. Thus, it is thought that direct waves will adversely affect the performance of spatial filtering and equalization techniques used to enhance signal detection. To examine the feasibility of MIMO-UWB systems, we conducted MIMO-UWB system propagation measurements in LOS environments. From the measurements, we found that the arrival time of direct waves from different transmitting antennas depends on the MIMO configuration. Because we can obtain high power from the direct waves, direct wave reception is critical for maximizing transmission performance. In this paper, we present our measurement results, and propose a way to improve performance using a method of transmit (Tx) and receive (Rx) timing control. We evaluate the bit error rate (BER) performance for this form of timing control using measured channel data.

  13. UWB Technology and Applications on Space Exploration

    NASA Technical Reports Server (NTRS)

    Ngo, Phong; Phan, Chau; Gross, Julia; Dusl, John; Ni, Jianjun; Rafford, Melinda

    2006-01-01

    Ultra-wideband (UWB), also known as impulse or carrier-free radio technology, is one promising new technology. In February 2002, the Federal Communications Commission (FCC) approved the deployment of this technology. It is increasingly recognized that UWB technology holds great potential to provide significant benefits in many terrestrial and space applications such as precise positioning/tracking and high data rate mobile wireless communications. This talk presents an introduction to UWB technology and some applications on space exploration. UWB is characterized by several uniquely attractive features, such as low impact on other RF systems due to its extremely low power spectral densities, immunity to interference from narrow band RF systems due to its ultra-wide bandwidth, multipath immunity to fading due to ample multipath diversity, capable of precise positioning due to fine time resolution, capable of high data rate multi-channel performance. The related FCC regulations, IEEE standardization efforts and industry activities also will be addressed in this talk. For space applications, some projects currently under development at NASA Johnson Space Center will be introduced. These include the UWB integrated communication and tracking system for Lunar/Mars rover and astronauts, UWB-RFID ISS inventory tracking, and UWB-TDOA close-in high resolution tracking for potential applications on robonaut.

  14. An adaptive line enhancement method for UWB proximity fuze signal processing based on correlation matrix estimation with time delay factor

    NASA Astrophysics Data System (ADS)

    Li, Meng; Huang, Zhonghua

    2016-10-01

    Signal processing for an ultra-wideband radio fuze receiver involves some challenges: it requires high real-time performance; the output signal is mixed with broadband noise; and the signal-to-noise ratio (SNR) decreases with increased detection range. The adaptive line enhancement method is used to filter the output signal of the ultra-wideband radio fuze receiver, and thus suppress the wideband noise from the output signal of the receiver and extract the target characteristic signal. The filter input correlation matrix estimation algorithm is based on the delay factor of an adaptive line enhancer. The proposed adaptive algorithm was used to filter and reduce noise in the output signal from the fuze receiver. Simulation results showed that the SNR of the output signal after adaptive noise reduction was improved by 20 dB, which was higher than the SNR of the output signal after finite impulse response (FIR) filtering of around 10 dB.

  15. UWB technology for safety-oriented vehicular communications

    NASA Astrophysics Data System (ADS)

    Llorente, Roberto; Morant, Maria

    2016-03-01

    Ultra-Wide Band (UWB) technology for wireless multiple access communications are receiving great interest for the last five years due to its unique features such as spectrum coexistence with other wireless services, RF front-end simplicity (enabling potential low cost terminals), good radio wave propagation (robust against multi-path fading, material penetration) and high bitrate. Low-cost UWB technology can be employed to provide simultaneous communications and vehicular radar capabilities. In this paper, the application of vehicle-to-vehicle (C2C), infrastructure-to-vehicle (I2C), communication and vehicular radar (VRAD) based on UWB technology are proposed altogether the required fiber-optics infrastructure, with the advantage of being flexible, cost-effective, reliable, fast and secure. The experimental validation and comparison for the optical generation of UWB signals combined with radio-over-fiber transmission is also reported in this work applied to vehicular communications. Both impulse-radio (IR-UWB) and orthogonal frequency division multiplexing (OFDM-UWB) signals are generated and their performance are evaluated experimentally in the 3.1-10.6 GHz frequency range. Up-conversion in the 60 GHz wireless band is also herein reported.

  16. Intruder detection and tracking using UWB technology

    NASA Astrophysics Data System (ADS)

    Schiavone, Guy A.; Wahid, Parveen; Palaniappan, Ravishankar; Tracy, Judd; Vandoorn, Eric; Micikevicius, Paulis; Hughes, Charles

    2004-08-01

    UWB communication is essentially the transmission and receiving of ultra short electromagnetic energy pulses. Short pulses mean wide bandwidths, often greatly exceeding 25% of the nominal center frequency. Modern UWB radio is characterized by very low power transmission (in the range of tens of microwatts) and wide bandwidths (greater than a gigahertz). One of the major applications of Ultra-wide band technology has been for detection and tracking of intruders in different environments. Based on some of our previous work [1,2] we developed a hybrid Ray-tracing/FDTD technique to study the indoor and outdoor propagation of UWB signals. The basic goal of this paper is to describe the experimental and simulation studies that were conducted to locate and track an intruder inside a UWB sensor web system. The sensor was developed using the Time Domain P-200 device and the software was developed using MATLAB. Return scans from UWB devices are analyzed to determine the noise floor and the signal strength. Using the noise floor level a threshold level is set above which the alarm will be triggered to determine the presence of an intruder. The probability of false alarm (PFA) is also determined using the Signal-to-Noise ratio and the threshold. We vary the PFA to lower the false alarm to a minimum level. We also determine the noise statistics of the system using Non-parametric Kolmogorov-Smirnov (KS) test. Using this basic UWB sensor web system we will try to determine the physical dimensions of the intruder and also track multiple intruders on the system.

  17. Test and Evaluation Enhancements for Cognitive Radio Technologies

    DTIC Science & Technology

    2015-05-13

    Radio Technologies The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an official...Final Report: Test and Evaluation Enhancements for Cognitive Radio Technologies Report Title This document serves as the final report for the...Instrumentation Grant (W911NF-14-1-0042) TEST & EVALUATION ENHANCEMENTS FOR COGNITIVE RADIO TECHNOLOGIES Final Report Dr. Willie L. Thompson, II

  18. Performance comparison between UWB-IR and MB-OFDM with transmit diversity in implant communications.

    PubMed

    Shimizu, Yuto; Furukawa, Tomofumi; Anzai, Daisuke; Wang, Jianqing

    2015-01-01

    An ultra wideband (UWB) technology is a potential candidate for implant body area networks (BANs), where wireless communications are established between inside and outside of a human body. The UWB can accomplish higher data rate than the other frequency band for the implant communication. However, due to its high frequencies, the UWB signals suffer from quite large attenuation in the implant communication link, which makes it difficult to achieve reliable communications. For achieving reliable communication, it is well known that a spatial diversity technique is efficient without any frequency extension. In our previous works, we developed a transmit polarization diversity antenna for the UWB implant communication. However, optimal UWB modulation scheme for transmit diversity were rarely discussed. In this paper, in order to investigate the optimal UWB modulation schemes for implant communication with transmit diversity, we compare the communication performances of UWB-impulse radio (UWB-IR) and multiband-orthogonal frequency division multiplexing (MB-OFDM). For this purpose, we first analyze the propagation characteristics in the implant UWB channel, which ranges from 3.4 GHz to 4.8 GHz, using a finite difference time domain (FDTD) numerical analysis technique. Then, we evaluate and discuss the communication performances of both modulation schemes for the transmit polarization diversity from the viewpoint of the BER and the required transmit power.

  19. Radio-frequency wave enhanced runaway production rate

    SciTech Connect

    Chan, V.S.; McClain, F.W.

    1983-06-01

    Enhancement of runaway electron production (over that of an Ohmic discharge) can be achieved by the addition of radio-frequency waves. This effect is studied analytically and numerically using a two-dimensional Fokker--Planck quasilinear equation.

  20. Method of remote powering and detecting multiple UWB passive tags in an RFID system

    DOEpatents

    Dowla, Farid U [Castro Valley, CA; Nekoogar, Faranak [San Ramon, CA; Benzel, David M [Livermore, CA; Dallum, Gregory E [Livermore, CA; Spiridon, Alex [Palo Alto, CA

    2012-05-29

    A new Radio Frequency Identification (RFID), tracking, powering apparatus/system and method using coded Ultra-wideband (UWB) signaling is introduced. The proposed hardware and techniques disclosed herein utilize a plurality of passive UWB transponders in a field of an RFID-radar system. The radar system itself enables multiple passive tags to be remotely powered (activated) at about the same time frame via predetermined frequency UWB pulsed formats. Once such tags are in an activated state, an UWB radar transmits specific "interrogating codes" to put predetermined tags in an awakened status. Such predetermined tags can then communicate by a unique "response code" so as to be detected by an UWB system using radar methods.

  1. UWB Tracking System Design for Lunar/Mars Exploration

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Phan, Chau; Gross, Julia

    2006-01-01

    This paper describes a design effort for a prototype ultra-wideband (UWB) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being studied for use in tracking of lunar/Mars rovers during early exploration missions when satellite navigation systems are not available. The UWB technology is exploited to implement the tracking system due to its properties such as high data rate, fine time resolution, low power spectral density, and multipath immunity. A two-cluster prototype design using commercially available UWB products is proposed to implement the Angle Of Arrival (AOA) tracking methodology in this research effort. An AOA technique using the Time Difference Of Arrival (TDOA) information is utilized for location estimation in the prototype system, not only to exploit the precise time resolution possible with UWB signals, but also to eliminate the need for synchronization between the transmitter and the receiver. After the UWB radio at each cluster is used to obtain the TDOA estimates from the UWB signal sent from the target, the TDOA data is converted to AOA data to find the angle of arrival, assuming this is a far field application. Since the distance between two clusters is known, the target position is computed by a simple triangulation. Simulations show that the average tracking error at a range of 610 meters is 2.7595 meters, less than 0.5% of the tracking range. Outdoor tests to track the SCOUT vehicle (The Science Crew Operations and Utility Testbed) near the Meteor Crater, Flagstaff, Arizona were performed on September 12-13, 2005. The tracking performance was obtained with less than 1% tracking error at ranges up to 2000 feet. No RF interference with on-board GPS, video, voice and telemetry systems was detected. Outdoor tests demonstrated the UWB tracking capability.

  2. UWB Two-Cluster AOA Tracking Prototype System Design

    NASA Technical Reports Server (NTRS)

    Ngo, Phong H.; Arndt, D.; Phan, C.; Gross, J.; Jianjun; Rafford, Melinda

    2006-01-01

    This presentation discusses a design effort for a prototype ultra-wideband (UWB) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being studied for use in tracking of lunar/Mars rovers during early exploration missions when satellite navigation systems are not available. The UWB technology is exploited to implement the tracking system due to its properties such as fine time resolution, low power spectral density and multipath immunity. A two cluster prototype design using commercially available UWB radios is employed to implement the Angle of Arrival (AOA) tracking methodology in this design effort. In order to increase the tracking range, low noise amplifiers (LNA) and high gain horns are used at the receiving sides. Field tests were conducted jointly with the Science and Crew Operation Utility Testbed (SCOUT) vehicle near the Meteor Crater in Arizona to test the tracking capability for a moving target in an operational environment. These tests demonstrate that the UWB tracking system can co-exist with other on-board radio frequency (RF) communication systems (such as Global Positioning System (GPS), video, voice and telemetry systems), and that a tracking resolution less than 1% of the range can be achieved.

  3. UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction

    PubMed Central

    Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej; Eggers, Patrick C. F.; Olesen, Kim; Byskov, Claus; Pedersen, Gert Frølund

    2015-01-01

    A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1–5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists of two UWB antennas at the blade root and one UWB antenna at the blade tip. The detailed topology and challenges of this deflection sensing system are addressed. Due to the complexity of the problem, this paper will first realize the on-blade UWB radio link in the simplest case, where the tip antenna is situated outside (and on the surface of) a blade tip. To investigate this case, full-blade time-domain measurements are designed and conducted under different deflections. The detailed measurement setups and results are provided. If the root and tip antenna locations are properly selected, the first pulse is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics on this application are listed finally. PMID:26274964

  4. UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction.

    PubMed

    Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej; Eggers, Patrick C F; Olesen, Kim; Byskov, Claus; Pedersen, Gert Frølund

    2015-08-12

    A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1-5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists of two UWB antennas at the blade root and one UWB antenna at the blade tip. The detailed topology and challenges of this deflection sensing system are addressed. Due to the complexity of the problem, this paper will first realize the on-blade UWB radio link in the simplest case, where the tip antenna is situated outside (and on the surface of) a blade tip. To investigate this case, full-blade time-domain measurements are designed and conducted under different deflections. The detailed measurement setups and results are provided. If the root and tip antenna locations are properly selected, the first pulse is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics on this application are listed finally.

  5. Enhancing the Radio Astronomy Capabilities at NASA's Deep Space Network

    NASA Astrophysics Data System (ADS)

    Lazio, Joseph; Teitelbaum, Lawrence; Franco, Manuel M.; Garcia-Miro, Cristina; Horiuchi, Shinji; Jacobs, Christopher; Kuiper, Thomas; Majid, Walid

    2015-08-01

    NASA's Deep Space Network (DSN) is well known for its role in commanding and communicating with spacecraft across the solar system that produce a steady stream of new discoveries in Astrophysics, Heliophysics, and Planetary Science. Equipped with a number of large antennas distributed across the world, the DSN also has a history of contributing to a number of leading radio astronomical projects. This paper summarizes a number of enhancements that are being implemented currently and that are aimed at increasing its capabilities to engage in a wide range of science observations. These enhancements include* A dual-beam system operating between 18 and 27 GHz (~ 1 cm) capable of conducting a variety of molecular line observations, searches for pulsars in the Galactic center, and continuum flux density (photometry) of objects such as nearby protoplanetary disks* Enhanced spectroscopy and pulsar processing backends for use at 1.4--1.9 GHz (20 cm), 18--27 GHz (1 cm), and 38--50 GHz (0.7 cm)* The DSN Transient Observatory (DTN), an automated, non-invasive backend for transient searching* Larger bandwidths (>= 0.5 GHz) for pulsar searching and timing; and* Improved data rates (2048 Mbps) and better instrumental response for very long baseline interferometric (VLBI) observations with the new DSN VLBI processor (DVP), which is providing unprecedented sensitivity for maintenance of the International Celestial Reference Frame (ICRF) and development of future versions.One of the results of these improvements is that the 70~m Deep Space Station 43 (DSS-43, Tidbinbilla antenna) is now the most sensitive radio antenna in the southern hemisphere. Proposals to use these systems are accepted from the international community.Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics & Space Administration.

  6. GPS/UWB/MEMS-IMU tightly coupled navigation with improved robust Kalman filter

    NASA Astrophysics Data System (ADS)

    Li, Zengke; Chang, Guobin; Gao, Jingxiang; Wang, Jian; Hernandez, Alberto

    2016-12-01

    The integration of Global Positioning System (GPS) with Inertial Navigation System (INS) has been very intensively developed and widely applied in multiple areas. To further enhance the reliability and availability of GPS/INS integrated navigation in GPS challenging environment, range observation through ultra-wideband (UWB) is introduced in GPS/INS tightly coupled navigation. An improved robust Kalman filter is proposed and used to resist the influence of gross error from UWB observation in GPS/UWB/IMU tightly coupled navigation. The variance of the squared Mahalanobis distance in moving window is calculated, which brings as new judgement factor for gross errors in order to decrease the rate of false outlier identification. A simulation analysis shows that the improved robust Kalman filter is able to correctly identify gross errors and the rate of false judgment as zero. In order to validate the new robust filter, a real experiment is conducted. The results indicate that the improved robust Kalman filter used in GPS/UWB/INS tightly coupled navigation is able to remove the harmful effect of gross error in UWB observation. It clearly illustrates that the improved robust Kalman filter is very effective, and all the simulated small and large gross errors added to UWB distance observation are successfully identified.

  7. Provision of IR-UWB wireless and baseband wired services over a WDM-PON.

    PubMed

    Pan, Shilong; Yao, Jianping

    2011-12-12

    A simple scheme to simultaneously generate an on-off keying or bi-phase modulation (BPM) impulse radio ultra wideband (IR-UWB) signal and a baseband wired signal in the optical domain using a dual-drive modulator is proposed and demonstrated. Although the two signals have spectral overlap in the optical spectrum, they are located at different frequency bands when converted to electrical signals at a photodetector (PD), which can be well separated by an electrical filter. An experiment is carried out. Eye diagrams, electrical spectra and BER measurements show that the co-channel interference between the UWB and the wired signals is small for a single-channel 36-km fiber link to provide 1.25-Gb/s UWB wireless and 1.25-Gb/s baseband wired services. The inter-channel interference is also small and negligible when the link is operated together with two other 1.25 Gb/s baseband wired links, which demonstrates that a conventional WDM-PON can be upgraded to provide additional UWB services without affecting the existing services by modifying the modulators in the center office and inserting UWB antennas in the optical network units.

  8. Matched filter design optimisation for UWB receiver for sensor network application

    NASA Astrophysics Data System (ADS)

    Naik, Rohit; Singh, Jugdutt; Veljanovski, Ronny

    2005-12-01

    Ultra Wideband (UWB) communications is one of the possible solutions for future wireless personal area network (WPAN) applications. The Federal Communications Commission (FCC), in the USA, allocated 7.5 GHz of unlicensed frequency bandwidth from 3.1 GHz to 10.6 GHz for UWB communication. It is an available spectrum which can be utilised for data communication using different technologies complying with FCC regulations. This paper presents a brief overview of the world wide regulations and Institute of Electrical and Electronic Engineers (IEEE) standardisation updates for UWB. It also focuses on the wireless sensor network application and the use of UWB communications in biomedical sensor networks. The paper aims at the design and implementation of an optimised pulsed matched filter (OPMF) used in the digital backend of a UWB radio. The optimisations are performed at the architectural and circuit level in order to reduce hardware complexity and reduced power. The OPMF is successfully implemented using the application specific integrated circuit (ASIC) design methodology and the results are compared with those obtained in previous implementation. The OPMF implementation presented in this paper yields improved characteristics such as reduction in area, almost 25% power reduction and better timing.

  9. A framework for UWB-based communication and location tracking systems for wireless sensor networks.

    PubMed

    Chóliz, Juan; Hernández, Angela; Valdovinos, Antonio

    2011-01-01

    Ultra wideband (UWB) radio technology is nowadays one of the most promising technologies for medium-short range communications. It has a wide range of applications including wireless sensor networks (WSN) with simultaneous data transmission and location tracking. The combination of location and data transmission is important in order to increase flexibility and reduce the cost and complexity of the system deployment. In this scenario, accuracy is not the only evaluation criteria, but also the amount of resources associated to the location service, as it has an impact not only on the location capacity of the system but also on the sensor data transmission capacity. Although several studies can be found in the literature addressing UWB-based localization, these studies mainly focus on distance estimation and position calculation algorithms. Practical aspects such as the design of the functional architecture, the procedure for the transmission of the associated information between the different elements of the system, and the need of tracking multiple terminals simultaneously in various application scenarios, are generally omitted. This paper provides a complete system level evaluation of a UWB-based communication and location system for Wireless Sensor Networks, including aspects such as UWB-based ranging, tracking algorithms, latency, target mobility and MAC layer design. With this purpose, a custom simulator has been developed, and results with real UWB equipment are presented too.

  10. 47 CFR 15.507 - Marketing of UWB equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Marketing of UWB equipment. 15.507 Section 15... Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is limited to... state or local government. The marketing of UWB devices must be directed solely to parties eligible...

  11. 47 CFR 15.507 - Marketing of UWB equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Marketing of UWB equipment. 15.507 Section 15... Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is limited to... state or local government. The marketing of UWB devices must be directed solely to parties eligible...

  12. 47 CFR 15.507 - Marketing of UWB equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Marketing of UWB equipment. 15.507 Section 15... Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is limited to... state or local government. The marketing of UWB devices must be directed solely to parties eligible...

  13. 47 CFR 15.507 - Marketing of UWB equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Marketing of UWB equipment. 15.507 Section 15... Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is limited to... state or local government. The marketing of UWB devices must be directed solely to parties eligible...

  14. 47 CFR 15.507 - Marketing of UWB equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Marketing of UWB equipment. 15.507 Section 15... Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is limited to... state or local government. The marketing of UWB devices must be directed solely to parties eligible...

  15. UWB pulse propagation into human tissues

    NASA Astrophysics Data System (ADS)

    Cavagnaro, Marta; Pittella, Erika; Pisa, Stefano

    2013-12-01

    In this paper the propagation of a UWB pulse into a layered model of the human body is studied to characterize absorption and reflection of the UWB signal due to the different body tissues. Several time behaviours for the incident UWB pulse are considered and compared with reference to the feasibility of breath and heartbeat activity monitoring. Results show that if the UWB source is placed far from the human body, the reflection coming from the interface between air and skin can be used to detect the respiratory activity. On the contrary, if the UWB source is placed close to the human body, a small reflection due to the interface between the posterior lung wall and the bone, which is well distanced in time from the reflections due to the first layers of the body model, can be used to detect lung and heart changes associated with the cardio-respiratory activity.

  16. UWB dual burst transmit driver

    SciTech Connect

    Dallum, Gregory E; Pratt, Garth C; Haugen, Peter C; Zumstein, James M; Vigars, Mark L; Romero, Carlos E

    2012-04-17

    A dual burst transmitter for ultra-wideband (UWB) communication systems generates a pair of precisely spaced RF bursts from a single trigger event. An input trigger pulse produces two oscillator trigger pulses, an initial pulse and a delayed pulse, in a dual trigger generator. The two oscillator trigger pulses drive a gated RF burst (power output) oscillator. A bias driver circuit gates the RF output oscillator on and off and sets the RF burst packet width. The bias driver also level shifts the drive signal to the level that is required for the RF output device.

  17. FDTD simulation tools for UWB antenna analysis.

    SciTech Connect

    Brocato, Robert Wesley

    2005-02-01

    This paper describes the development of a set of software tools useful for analyzing ultra-wideband (UWB) antennas and structures. These tools are used to perform finite difference time domain (FDTD) simulation of a conical antenna with continuous wave (CW) and UWB pulsed excitations. The antenna is analyzed using spherical coordinate-based FDTD equations that are derived from first principles. The simulation results for CW excitation are compared to simulation and measured results from published sources; the results for UWB excitation are new.

  18. FDTD simulation tools for UWB antenna analysis.

    SciTech Connect

    Brocato, Robert Wesley

    2004-12-01

    This paper describes the development of a set of software tools useful for analyzing ultra-wideband (UWB) antennas and structures. These tools are used to perform finite difference time domain (FDTD) simulation of a conical antenna with continuous wave (CW) and UWB pulsed excitations. The antenna is analyzed using spherical coordinate-based FDTD equations that are derived from first principles. The simulation results for CW excitation are compared to simulation and measured results from published sources; the results for UWB excitation are new.

  19. On IEEE 802.15.6 IR-UWB receivers - simulations for DBPSK modulation.

    PubMed

    Niemelä, Ville; Hämäläinen, Matti; Iinatti, Jari

    2013-01-01

    In 2002, Federal Communications Commission (FCC) was the first in defining regulations for ultra wideband (UWB) communications followed by Europe and Japan some years later. Focusing on impulse radio (IR) UWB, in 2007 was the time for the first published standard targeting in personal area networks, released by the IEEE. The second IEEE released standard including UWB definitions is targeted for wireless body area networks (WBAN) and was published in 2012. As the wireless communications has been and will be passing through almost any levels in society, the natural step with WBAN is using it in different medical, healthcare and wellbeing applications. The arguments for these are related to the modern lifestyle, in which people have increasingly more free time and are more interested in taking care of their health and wellbeing. Another challenge is the population composition, i.e., aging in developed countries which call for new solutions and procedures, particularly from cost wise. In this paper, we are evaluating UWB receivers based on the IEEE 802.15.6 physical layer definitions and capable of detecting differentially encoded modulation. The evaluation is performed using two different WBAN channel models.

  20. ASIC Implementation of Highly Reliable IR-UWB Transceiver for Industrial Automation

    NASA Astrophysics Data System (ADS)

    Olonbayar, Sonom; Fischer, Gunter; Kreiser, Dan; Martynenko, Denys; Klymenko, Oleksiy; Kraemer, Rolf; Grass, Eckhard

    2016-07-01

    An in-depth treatment of impulse an radio ultra-wideband (IR-UWB) wireless system is provided reviewing theoretical background, proceeding with detailed implementation procedure, and finally giving simulation and test results. This is the first research and prototyping work to be published in the field of IR-UWB that operates in the 6-8 GHz band. The aim of this work is to implement an IR-UWB wireless system for industrial automation that is robust and reliable. To achieve this, an analogue bandwidth of 250 MHz and digital baseband processing at the clock frequency 499.2 MHz were realized in a 250 nm BiCMOS process, integrating the complete system into a single chip. Simulation and measurement results confirm that the implemented IR-UWB transceiver is operational across four frequency channels in the band 6-8 GHz each supporting three data rates 850 kb/s, 6.81 Mb/s and 27.24 Mb/s.

  1. Interplanetary Proton and Electron Enhancements Associated with Radio-loud and Radio-quiet CME-driven Shocks

    NASA Astrophysics Data System (ADS)

    Makela, P. A.; Gopalswamy, N.; Xie, H.; Akiyama, S.; Yashiro, S.

    2009-12-01

    We present the results on electron and proton acceleration in association with radio-quiet (RQ) and radio-loud (RL) shocks driven by coronal mass ejections (CMEs) during 1996-2006. The CME-driven shocks are classified into RL or RQ shocks based on the presence or the lack of type II radio bursts in the metric and decameter-hectometric wavelength range. We studied proton flux enhancements at L1 in the 66 keV - 50 MeV energy range observed by the ACE/EPAM and SOHO/ERNE instruments. Electron flux enhancements were studied in the 38-53~keV energy channel of EPAM. In general, the RL shocks are more likely to be associated with an energetic storm particle (ESP) event than RQ shocks. Approximately one third of RQ shocks and slightly over a half of RL shocks produced an ESP event at energies above 1.8 MeV. In overall both RQ and RL electron ESP events are rarer, but they follow a similar pattern to the proton observations, i.e. ESP events are observed in approximately one fifth versus two fifths of shocks, respectively. We also studied correlations of ESP event size with CME and shock properties. As expected, the ESP events associated with the RQ shocks are less intense than those with RL shocks. In addition, particle acceleration in RQ shocks occurs predominately in quasi-perpendicular shocks. There is a modest positive correlation between ESP event size and the CME and shock speed and the Mach number. Again, the correlations are stronger for the RL shocks. It appears that shocks can accelerate particles, although less efficiently, even when they do not produce observable type II radio bursts. The variation between the presence of type IIs and ESP events is probably connected to variations in the coronal conditions of shock formation and to the consequent evolution of the shock as it travels through diverse coronal and interplanetary plasmas.

  2. UWB delay and multiply receiver

    SciTech Connect

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  3. Optimised implementation of a matched filter bank for ultrawideband radios

    NASA Astrophysics Data System (ADS)

    Muthuswamy, Sivanandan; Veljanovski, Ronny; Singh, Jugdutt

    2005-02-01

    Ultra-wideband (UWB) technology dates back to early 1980s and was originally employed in radar applications. Unlike any narrowband or broadband communication systems, an UWB system does not employ any radio frequency (RF) carrier for data transmission. Instead it uses very short period electrical pulses in the order of hundreds of pico-seconds to few nano-seconds, which justifies the availability of an ultra-high bandwidth. From a hardware implementation viewpoint, UWB system design presents many challenges such as synchronisation, power limitation and receiver design. However, the design of an UWB transceiver is less complex given the fact that the RF carrier is eliminated. In an UWB transceiver, most of the processing is performed in the digital baseband while the analog front end is responsible for amplification, filtering and quantisation. A bank of matched filters constitutes the major portion of digital baseband section in an UWB transceiver. This paper presents the design, optimisation and field programmable gate array (FPGA) implementation of the matched filter bank as an attempt to minimise the overall circuit complexity, achieve higher data rates and low power consumption in UWB radios.

  4. Improving the power efficiency of SOA-based UWB over fiber systems via pulse shape randomization

    NASA Astrophysics Data System (ADS)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2016-09-01

    A simple pulse shape randomization scheme is considered in this paper for improving the performance of ultra wide band (UWB) communication systems using On Off Keying (OOK) or pulse position modulation (PPM) formats. The advantage of the proposed scheme, which can be either employed for impulse radio (IR) or for carrier-based systems, is first theoretically studied based on closed-form derivations of power spectral densities. Then, we investigate an application to an IR-UWB over optical fiber system, by utilizing the 4th and 5th orders of Gaussian derivatives. Our approach proves to be effective for 1 Gbps-PPM and 2 Gbps-OOK transmissions, with an advantage in terms of power efficiency for short distances. We also examine the performance for a system employing an in-line Semiconductor Optical Amplifier (SOA) with the view to achieve a reach extension, while limiting the cost and system complexity.

  5. Growth Enhancement of Radish Sprouts Induced by Low Pressure O2 Radio Frequency Discharge Plasma Irradiation

    NASA Astrophysics Data System (ADS)

    Kitazaki, Satoshi; Koga, Kazunori; Shiratani, Masaharu; Hayashi, Nobuya

    2012-01-01

    We studied growth enhancement of radish sprouts (Raphanus sativus L.) induced by low pressure O2 radio frequency (RF) discharge plasma irradiation. The average length of radish sprouts cultivated for 7 days after O2 plasma irradiation is 30-60% greater than that without irradiation. O2 plasma irradiation does not affect seed germination. The experimental results reveal that oxygen related radicals strongly enhance growth, whereas ions and photons do not.

  6. UWB Tracking Algorithms: AOA and TDOA

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun David; Arndt, D.; Ngo, P.; Gross, J.; Refford, Melinda

    2006-01-01

    Ultra-Wideband (UWB) tracking prototype systems are currently under development at NASA Johnson Space Center for various applications on space exploration. For long range applications, a two-cluster Angle of Arrival (AOA) tracking method is employed for implementation of the tracking system; for close-in applications, a Time Difference of Arrival (TDOA) positioning methodology is exploited. Both AOA and TDOA are chosen to utilize the achievable fine time resolution of UWB signals. This talk presents a brief introduction to AOA and TDOA methodologies. The theoretical analysis of these two algorithms reveal the affecting parameters impact on the tracking resolution. For the AOA algorithm, simulations show that a tracking resolution less than 0.5% of the range can be achieved with the current achievable time resolution of UWB signals. For the TDOA algorithm used in close-in applications, simulations show that the (sub-inch) high tracking resolution is achieved with a chosen tracking baseline configuration. The analytical and simulated results provide insightful guidance for the UWB tracking system design.

  7. A Tightly-Coupled GPS/INS/UWB Cooperative Positioning Sensors System Supported by V2I Communication.

    PubMed

    Wang, Jian; Gao, Yang; Li, Zengke; Meng, Xiaolin; Hancock, Craig M

    2016-06-27

    This paper investigates a tightly-coupled Global Position System (GPS)/Ultra-Wideband (UWB)/Inertial Navigation System (INS) cooperative positioning scheme using a Robust Kalman Filter (RKF) supported by V2I communication. The scheme proposes a method that uses range measurements of UWB units transmitted among the terminals as augmentation inputs of the observations. The UWB range inputs are used to reform the GPS observation equations that consist of pseudo-range and Doppler measurements and the updated observation equation is processed in a tightly-coupled GPS/UWB/INS integrated positioning equation using an adaptive Robust Kalman Filter. The result of the trial conducted on the roof of the Nottingham Geospatial Institute (NGI) at the University of Nottingham shows that the integrated solution provides better accuracy and improves the availability of the system in GPS denied environments. RKF can eliminate the effects of gross errors. Additionally, the internal and external reliabilities of the system are enhanced when the UWB observables received from the moving terminals are involved in the positioning algorithm.

  8. A Tightly-Coupled GPS/INS/UWB Cooperative Positioning Sensors System Supported by V2I Communication

    PubMed Central

    Wang, Jian; Gao, Yang; Li, Zengke; Meng, Xiaolin; Hancock, Craig M.

    2016-01-01

    This paper investigates a tightly-coupled Global Position System (GPS)/Ultra-Wideband (UWB)/Inertial Navigation System (INS) cooperative positioning scheme using a Robust Kalman Filter (RKF) supported by V2I communication. The scheme proposes a method that uses range measurements of UWB units transmitted among the terminals as augmentation inputs of the observations. The UWB range inputs are used to reform the GPS observation equations that consist of pseudo-range and Doppler measurements and the updated observation equation is processed in a tightly-coupled GPS/UWB/INS integrated positioning equation using an adaptive Robust Kalman Filter. The result of the trial conducted on the roof of the Nottingham Geospatial Institute (NGI) at the University of Nottingham shows that the integrated solution provides better accuracy and improves the availability of the system in GPS denied environments. RKF can eliminate the effects of gross errors. Additionally, the internal and external reliabilities of the system are enhanced when the UWB observables received from the moving terminals are involved in the positioning algorithm. PMID:27355947

  9. Location detection and tracking of moving targets by a 2D IR-UWB radar system.

    PubMed

    Nguyen, Van-Han; Pyun, Jae-Young

    2015-03-19

    In indoor environments, the Global Positioning System (GPS) and long-range tracking radar systems are not optimal, because of signal propagation limitations in the indoor environment. In recent years, the use of ultra-wide band (UWB) technology has become a possible solution for object detection, localization and tracking in indoor environments, because of its high range resolution, compact size and low cost. This paper presents improved target detection and tracking techniques for moving objects with impulse-radio UWB (IR-UWB) radar in a short-range indoor area. This is achieved through signal-processing steps, such as clutter reduction, target detection, target localization and tracking. In this paper, we introduce a new combination consisting of our proposed signal-processing procedures. In the clutter-reduction step, a filtering method that uses a Kalman filter (KF) is proposed. Then, in the target detection step, a modification of the conventional CLEAN algorithm which is used to estimate the impulse response from observation region is applied for the advanced elimination of false alarms. Then, the output is fed into the target localization and tracking step, in which the target location and trajectory are determined and tracked by using unscented KF in two-dimensional coordinates. In each step, the proposed methods are compared to conventional methods to demonstrate the differences in performance. The experiments are carried out using actual IR-UWB radar under different scenarios. The results verify that the proposed methods can improve the probability and efficiency of target detection and tracking.

  10. A Wireless FSCV Monitoring IC with Analog Background Subtraction and UWB Telemetry

    PubMed Central

    Dorta-Quiñones, Carlos I.; Wang, Xiao Y.; Dokania, Rajeev K.; Gailey, Alycia; Lindau, Manfred; Apsel, Alyssa B.

    2015-01-01

    A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5-mm2 chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pArms and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm2, weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV. PMID:26057983

  11. A Wireless FSCV Monitoring IC With Analog Background Subtraction and UWB Telemetry.

    PubMed

    Dorta-Quiñones, Carlos I; Wang, Xiao Y; Dokania, Rajeev K; Gailey, Alycia; Lindau, Manfred; Apsel, Alyssa B

    2016-04-01

    A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5- mm(2) chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pA(rms) and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm(2), weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV.

  12. Performance evaluation on FPGA-implemented UWB-IR receiver for in-body to out-of-body communication systems.

    PubMed

    Shimizu, Yuto; Anzai, Daisuke; Jianqing Wang

    2014-01-01

    In order to design an optimized transceiver structure of ultra wideband (UWB) transmission in in-body to out-of-body communications, it is necessary to make the transceiver structure be easily adjustable in order to realize a good communication performance in an experimental environment. For this purpose, we first implement our develop UWB-impulse radio (IR) receiver structure for the in-body to out-of-body communication in a field programmable gate array (FPGA) board, and evaluate the fundamental communication performance of the FPGA-implemented UWB-IR receiver by a biological-equivalent liquid phantom experiment. The FPGA configuration results indicate that our FPGA realization of the UWB-IR receiver has accomplished good communication performance with few FPGA slices. Moreover, the evaluation results in the liquid phantom experiment show that the FPGA-implemented UWB-IR receiver can achieve a bit error rate (BER) of 10(-3) up to a communication distance of 70 mm with ensuring a high data rate of 2 Mbps.

  13. UWB Impulse Radar Characterization and Processing Techniques

    DTIC Science & Technology

    2004-12-01

    S/B s’améliore de façon à peu près linéaire . L’intégration d’environ 80 impulsions donne lieu à un rapport S/B maximal d’environ 35 dB, avec une...défense Canada (RDDC) a un programme de recherche active sur bien des aspects des systèmes radar à bande ultra-large (UWB), y compris la simulation

  14. UWB Tracking System Design with TDOA Algorithm

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Phan, Chau; Gross, Julia; Dusl, John; Schwing, Alan

    2006-01-01

    This presentation discusses an ultra-wideband (UWB) tracking system design effort using a tracking algorithm TDOA (Time Difference of Arrival). UWB technology is exploited to implement the tracking system due to its properties, such as high data rate, fine time resolution, and low power spectral density. A system design using commercially available UWB products is proposed. A two-stage weighted least square method is chosen to solve the TDOA non-linear equations. Matlab simulations in both two-dimensional space and three-dimensional space show that the tracking algorithm can achieve fine tracking resolution with low noise TDOA data. The error analysis reveals various ways to improve the tracking resolution. Lab experiments demonstrate the UWBTDOA tracking capability with fine resolution. This research effort is motivated by a prototype development project Mini-AERCam (Autonomous Extra-vehicular Robotic Camera), a free-flying video camera system under development at NASA Johnson Space Center for aid in surveillance around the International Space Station (ISS).

  15. UWB Tracking System Design for Free-Flyers

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun; Arndt, Dickey; Phan, Chan; Ngo, Phong; Gross, Julia; Dusl, John

    2004-01-01

    This paper discusses an ultra-wideband (UWB) tracking system design effort for Mini-AERCam (Autonomous Extra-vehicular Robotic Camera), a free-flying video camera system under development at NASA Johnson Space Center for aid in surveillance around the International Space Station (ISS). UWB technology is exploited to implement the tracking system due to its properties, such as high data rate, fine time resolution, and low power spectral density. A system design using commercially available UWB products is proposed. A tracking algorithm TDOA (Time Difference of Arrival) that operates cooperatively with the UWB system is developed in this research effort. Matlab simulations show that the tracking algorithm can achieve fine tracking resolution with low noise TDOA data. Lab experiments demonstrate the UWB tracking capability with fine resolution.

  16. Fabrication of CPW-Fed Fractal Antenna for UWB Applications with Omni-Directional Patterns

    PubMed Central

    Sedghi, Tohid; Jalali, Mahdi; Aribi, Tohid

    2014-01-01

    Novel and compact CPW-fed antennas are proposed comprised of a fractal patch and modified ground-plane. The ground-plane is truncated at the center and includes dielectric notches at its side to enhance the antenna's impedance bandwidth. The dimensions of the notches effectively control the upper and lower band edges of the antenna. The optimized antenna operates across 2.95–12.81 GHz for S11 ≤ −10 dB. Omnidirectional radiation pattern is achieved over the full UWB frequency range. The miniaturized antenna has a total size of 14 × 18 × 1 mm3. The characteristics of the proposed antenna are suitable for UWB wireless communication requiring low profile antennas. PMID:24672314

  17. Amorphous hollow carbon spheres synthesized using radio frequency plasma-enhanced chemical vapour deposition

    NASA Astrophysics Data System (ADS)

    Yang, G. M.; Xu, Q.; Tian, H. W.; Wang, X.; Zheng, W. T.

    2008-10-01

    We report a method to synthesize amorphous hollow carbon spheres, with diameters ranging from 100 to 800 nm, which are dispersed among bent graphitized carbon nanotubes using radio frequency plasma-enhanced chemical vapour deposition in mixed CH4/H2 gases. The products are characterized by techniques including scanning electron microscopy, energy-dispersive x-ray spectroscopy, Raman spectroscopy and transmission electron microscopy. It is found that MgO and Ni nanoparticles together with hydrogen play important roles in the formation of the spheres. A possible formation mechanism for the carbon composites has been proposed.

  18. Photonic ultrawideband impulse radio generation and modulation over a fiber link using a phase modulator and a delay interferometer.

    PubMed

    Shao, Jing; Sun, Junqiang

    2012-08-15

    We propose and experimentally demonstrate a simple and flexible photonic scheme for generation and modulation of ultrawideband (UWB) using a phase modulator and a fiber delay interferometer (DI)-based multichannel frequency discrimination. By introducing a Gaussian signal to the phase modulator, the UWB polarity-switchable doublet pulses can be achieved by combining the pair of UWB monocycle pulses with inverted polarities at the DI outputs under proper time delay. Furthermore, the pulse shape modulation, pulse position modulation, and on-off keying can be performed by coding the electrical data patterns and adjusting the time delay between the two monocycle pulses. Only a laser source introduced in the architecture guarantees the excellent dispersion tolerance over 75 km optical fiber link for UWB pulse sequence, which has potential application in future high-speed UWB impulse radio over optical fiber access networks.

  19. Sorafenib inhibits cell growth but fails to enhance radio- and chemosensitivity of glioblastoma cell lines

    PubMed Central

    Riedel, Matthias; Struve, Nina; Müller-Goebel, Justus; Köcher, Sabrina; Petersen, Cordula; Dikomey, Ekkehard; Rothkamm, Kai; Kriegs, Malte

    2016-01-01

    Background Glioblastomas (GBM) are the most common malignant type of primary brain tumor. GBM are intensively treated with surgery and combined radiochemotherapy using X-irradiation and temozolomide (TMZ) but they are still associated with an extremely poor prognosis, urging for the development of new treatment strategies. To improve the outcome of GBM patients, the small molecule multi-kinase inhibitor sorafenib has moved into focus of recent research. Sorafenib has already been shown to enhance the radio- and radiochemosensitivity of other tumor entities. Whether sorafenib is also able to sensitize GBM cells to radio- and chemotherapy is still an unsolved question which we have addressed in this study. Methods The effect of sorafenib on signaling, proliferation, radiosensitivity, chemosensitivity and radiochemosensitivity was analyzed in six glioblastoma cell lines using Western blot, proliferation- and colony formation assays. Results In half of the cell lines sorafenib clearly inhibited MAPK signaling. We also observed a strong blockage of proliferation, which was, however, not associated with MAPK pathway inhibition. Sorafenib had only minor effects on cell survival when administered alone. Most importantly, sorafenib treatment failed to enhance GBM cell killing by irradiation, TMZ or combined treatment, and instead rather caused resistance in some cell lines. Conclusion Our data suggest that sorafenib treatment may not improve the efficacy of radiochemotherapy in GBM. PMID:27542273

  20. Firefighters' Radios

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Public Technology Inc. asked for NASA assistance to devise the original firefighter's radio. Good short-range radio communications are essential during a fire to coordinate hose lines, rescue victims, and otherwise increase efficiency. Useful firefighting tool is lower cost, more rugged short range two-way radio. Inductorless electronic circuit replaced inductances and coils in radio circuits with combination of transistors and other low-cost components. Substitution promises reduced circuit size and cost. Enhanced electrical performance made radio more durable and improved maintainability by incorporating modular construction.

  1. Band-notched reconfigurable CPW-fed UWB antenna

    NASA Astrophysics Data System (ADS)

    Majid, H. A.; Rahim, M. K. A.; Hamid, M. R.; Murad, N. A.; Samsuri, N. A.; Yusof, M. F. M.; Kamarudin, M. R.

    2016-04-01

    A reconfigurable band-notched CPW-fed UWB antenna using electromagnetic bandgap (EBG) structure is proposed. Two structures are positioned adjacent to the transmission line of the UWB antenna. The band-notched characteristic can be disabled by switching the state of switch place at the strip line. The EBG structure produces reconfigurable band notched at 4.0 GHz, which covers C-band satellite communication (3.625-4.2 GHz) systems. The proposed antenna is suitable for UWB systems, which requires reconfigurable band reject function.

  2. Ultrawideband Electromagnetic Interference to Aircraft Radios

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Fuller, Gerald L.; Shaver, Timothy W.

    2002-01-01

    A very recent FCC Final Rule now permits marketing and operation of new products that incorporate Ultrawideband (UWB) technology into handheld devices. Wireless product developers are working to rapidly bring this versatile, powerful and expectedly inexpensive technology into numerous consumer wireless devices. Past studies addressing the potential for passenger-carried portable electronic devices (PEDs) to interfere with aircraft electronic systems suggest that UWB transmitters may pose a significant threat to aircraft communication and navigation radio receivers. NASA, United Airlines and Eagles Wings Incorporated have performed preliminary testing that clearly shows the potential for handheld UWB transmitters to cause cockpit failure indications for the air traffic control radio beacon system (ATCRBS), blanking of aircraft on the traffic alert and collision avoidance system (TCAS) displays, and cause erratic motion and failure of instrument landing system (ILS) localizer and glideslope pointers on the pilot horizontal situation and attitude director displays. This paper provides details of the preliminary testing and recommends further assessment of aircraft systems for susceptibility to UWB electromagnetic interference.

  3. Ketogenic Diets Enhance Oxidative Stress and Radio-Chemo-Therapy Responses in Lung Cancer Xenografts

    PubMed Central

    Allen, Bryan G.; Bhatia, Sudershan K.; Buatti, John M.; Brandt, Kristin E.; Lindholm, Kaleigh E.; Button, Anna M.; Szweda, Luke I.; Smith, Brian J.; Spitz, Douglas R.; Fath, Melissa A.

    2014-01-01

    Purpose Ketogenic diets (KDs) are high in fat and low in carbohydrates as well as protein which forces cells to rely on lipid oxidation and mitochondrial respiration rather than glycolysis for energy metabolism. Cancer cells (relative to normal cells) are believed to exist in a state of chronic oxidative stress mediated by mitochondrial metabolism. The current study tests the hypothesis that KDs enhance radio-chemo-therapy responses in lung cancer xenografts by enhancing oxidative stress. Experimental Design Mice bearing NCI-H292 and A549 lung cancer xenografts were fed a KD (KetoCal® 4:1 fats: proteins+carbohydrates) and treated with either conventionally fractionated (1.8-2 Gy) or hypofractionated (6 Gy) radiation as well as conventionally fractionated radiation combined with carboplatin. Mice weights and tumor size were monitored. Tumors were assessed for immuno-reactive 4-hydroxy-2-nonenal-(4HNE) modified proteins as a marker of oxidative stress as well as PCNA and γH2AX as indices of proliferation and DNA damage, respectively. Results The KD combined with radiation resulted in slower tumor growth in both NCI-H292 and A549 xenografts (p<0.05), relative to radiation alone. The KD also slowed tumor growth when combined with carboplatin and radiation, relative to control. Tumors from animals fed a KD in combination with radiation demonstrated increases in oxidative damage mediated by lipid peroxidation as determined by 4HNE-modified proteins as well as decreased proliferation as assessed by decreased immunoreactive PCNA. Conclusions These results show that a KD enhances radio-chemo-therapy responses in lung cancer xenografts by a mechanism that may involve increased oxidative stress. PMID:23743570

  4. Body Area Networks performance analysis using UWB.

    PubMed

    Fatehy, Mohammed; Kohno, Ryuji

    2013-01-01

    The successful realization of a Wireless Body Area Network (WBAN) using Ultra Wideband (UWB) technology supports different medical and consumer electronics (CE) applications but stand in a need for an innovative solution to meet the different requirements of these applications. Previously, we proposed to use adaptive processing gain (PG) to fulfill the different QoS requirements of these WBAN applications. In this paper, interference occurred between two different BANs in a UWB-based system has been analyzed in terms of acceptable ratio of overlapping between these BANs' PG providing the required QoS for each BAN. The first BAN employed for a healthcare device (e.g. EEG, ECG, etc.) with a relatively longer spreading sequence is used and the second customized for entertainment application (e.g. wireless headset, wireless game pad, etc.) where a shorter spreading code is assigned. Considering bandwidth utilization and difference in the employed spreading sequence, the acceptable ratio of overlapping between these BANs should fall between 0.05 and 0.5 in order to optimize the used spreading sequence and in the meantime satisfying the required QoS for these applications.

  5. Signal Enhancement with Stacked Magnets for High-Resolution Radio Frequency Glow Discharge Mass Spectrometry.

    PubMed

    Wei, Juan; Dong, Jiangli; Zhuo, Shangjun; Qian, Rong; Fang, Yuanxing; Chen, Qiao; Patel, Ekbal

    2017-01-17

    A method for signal enhancement utilizing stacked magnets was introduced into high-resolution radio frequency glow discharge-mass spectrometry (rf-GD-MS) for significantly improved analysis of inorganic materials. Compared to the block magnet, the stacked magnets method was able to achieve 50-59% signal enhancement for typical elements in Y2O3, BSO, and BTN samples. The results indicated that signal was enhanced as the increase of discharge pressure from 1.3 to 8.0 mPa, the increase of rf-power from 10 to 50 W with a frequency of 13.56 MHz, the decrease of sample thickness, and the increase of number of stacked magnets. The possible mechanism for the signal enhancement was further probed using the software "Mechanical APDL (ANSYS) 14.0". It was found that the distinct oscillated magnetic field distribution from the stacked magnets was responsible for signal enhancement, which could extend the movement trajectories of electrons and increase the collisions between the electrons and neutral particles to increase the ionization efficiency. Two NIST samples were used for the validation of the method, and the results suggested that relative errors were within 13% and detection limit for six transverse stacked magnets could reach as low as 0.0082 μg g(-1). Additionally, the stability of the method was also studied. RSD within 15% of the elements in three nonconducting samples could be obtained during the sputtering process. Together, the results showed that the signal enhancement method with stacked magnets could offer great promises in providing a sensitive, stable, and facile solution for analyzing the nonconducting materials.

  6. Software-Defined Ultra-wideband Radio Communications: A New RF Technology for Emergency Response Applications

    SciTech Connect

    Nekoogar, F; Dowla, F

    2009-10-19

    Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal of flexibility in operational parameters and helps the radio system to dynamically adapt itself to its environment for optimal performance.

  7. A Novel Design of Frequency Reconfigurable Antenna for UWB Application

    NASA Astrophysics Data System (ADS)

    Yang, Xiaolin; Yu, Ziliang; Wu, Zheng; Shen, Huajiao

    2016-09-01

    In this paper, we present a novel frequency reconfigurable antenna which could be easily operate in a single notched-band (WiMAX (3.3-3.6 GHz)) UWB frequency band, another single notched-band (WLAN (5-6 GHz)) UWB frequency band and the dual band-notched UWB frequency band (the stopband covers the WiMAX (3.3-3.6 GHz) and WLAN (5-6 GHz)). The reconfigurability is achieved by changing the states of PIN diodes. The simulated results are in agreement well with the measured results. And the measured patterns are slightly changed with antenna reconfiguration. The proposed antenna is a good candidate for various UWB applications.

  8. Automated handling of textile yarn packages to enhance radio frequency drying

    SciTech Connect

    Clapp, T.G. . Coll. of Textiles)

    1992-11-01

    The benefits of radio frequency (RF) dryers in the textile industry are well documented and include improved product quality, increased drying versatility, uniform drying, and enhanced flexibility for just-in-time (JIT) processing. In spite of these benefits, however, less than 25 of the 400 RF package dryers in use worldwide are located in North America because of the costs associated with additional materials handling operations. This report defines six yarn package handling work functions as candidates for automation, determines the justifiable corporate investment to automate these six functions, and discusses various investment levels and rates of return on such automation. The report also identifies 11 manufacturers that build customized automation equipment and details their systems.

  9. Automated handling of textile yarn packages to enhance radio frequency drying. Final report

    SciTech Connect

    Clapp, T.G.

    1992-11-01

    The benefits of radio frequency (RF) dryers in the textile industry are well documented and include improved product quality, increased drying versatility, uniform drying, and enhanced flexibility for just-in-time (JIT) processing. In spite of these benefits, however, less than 25 of the 400 RF package dryers in use worldwide are located in North America because of the costs associated with additional materials handling operations. This report defines six yarn package handling work functions as candidates for automation, determines the justifiable corporate investment to automate these six functions, and discusses various investment levels and rates of return on such automation. The report also identifies 11 manufacturers that build customized automation equipment and details their systems.

  10. Photonic generation and wireless transmission of different pulse modulation formats for high-speed impulse radio ultrawideband over fiber systems

    NASA Astrophysics Data System (ADS)

    Xie, Shizhong; Chen, Hongwei; Chen, Minghua; Yang, Sigang; Li, Pengxiao

    2011-12-01

    Novel methods on photonic generation of different pulse modulation formats for impulse radio ultra-wideband (IR-UWB) over fiber application is overviewed. A flexible, high-speed and power-efficient photonic on-off keying and binary phase shift keying modulated IR-UWB over fiber communication system is proposed and demonstrated. IR-UWB transmission over 20km fiber and 0.25m wireless link without any compensation is presented. The transmission performance for both modulation formats is evaluated and compared by measuring eye diagrams and the electrical spectra.

  11. Path loss variation of on-body UWB channel in the frequency bands of IEEE 802.15.6 standard.

    PubMed

    Goswami, Dayananda; Sarma, Kanak C; Mahanta, Anil

    2016-06-01

    The wireless body area network (WBAN) has gaining tremendous attention among researchers and academicians for its envisioned applications in healthcare service. Ultra wideband (UWB) radio technology is considered as excellent air interface for communication among body area network devices. Characterisation and modelling of channel parameters are utmost prerequisite for the development of reliable communication system. The path loss of on-body UWB channel for each frequency band defined in IEEE 802.15.6 standard is experimentally determined. The parameters of path loss model are statistically determined by analysing measurement data. Both the line-of-sight and non-line-of-sight channel conditions are considered in the measurement. Variations of parameter values with the size of human body are analysed along with the variation of parameter values with the surrounding environments. It is observed that the parameters of the path loss model vary with the frequency band as well as with the body size and surrounding environment. The derived parameter values are specific to the particular frequency bands of IEEE 802.15.6 standard, which will be useful for the development of efficient UWB WBAN system.

  12. Short-Range Vital Signs Sensing Based on EEMD and CWT Using IR-UWB Radar

    PubMed Central

    Hu, Xikun; Jin, Tian

    2016-01-01

    The radar sensor described realizes healthcare monitoring capable of detecting subject chest-wall movement caused by cardiopulmonary activities and wirelessly estimating the respiration and heartbeat rates of the subject without attaching any devices to the body. Conventional single-tone Doppler radar can only capture Doppler signatures because of a lack of bandwidth information with noncontact sensors. In contrast, we take full advantage of impulse radio ultra-wideband (IR-UWB) radar to achieve low power consumption and convenient portability, with a flexible detection range and desirable accuracy. A noise reduction method based on improved ensemble empirical mode decomposition (EEMD) and a vital sign separation method based on the continuous-wavelet transform (CWT) are proposed jointly to improve the signal-to-noise ratio (SNR) in order to acquire accurate respiration and heartbeat rates. Experimental results illustrate that respiration and heartbeat signals can be extracted accurately under different conditions. This noncontact healthcare sensor system proves the commercial feasibility and considerable accessibility of using compact IR-UWB radar for emerging biomedical applications. PMID:27916877

  13. Short-Range Vital Signs Sensing Based on EEMD and CWT Using IR-UWB Radar.

    PubMed

    Hu, Xikun; Jin, Tian

    2016-11-30

    The radar sensor described realizes healthcare monitoring capable of detecting subject chest-wall movement caused by cardiopulmonary activities and wirelessly estimating the respiration and heartbeat rates of the subject without attaching any devices to the body. Conventional single-tone Doppler radar can only capture Doppler signatures because of a lack of bandwidth information with noncontact sensors. In contrast, we take full advantage of impulse radio ultra-wideband (IR-UWB) radar to achieve low power consumption and convenient portability, with a flexible detection range and desirable accuracy. A noise reduction method based on improved ensemble empirical mode decomposition (EEMD) and a vital sign separation method based on the continuous-wavelet transform (CWT) are proposed jointly to improve the signal-to-noise ratio (SNR) in order to acquire accurate respiration and heartbeat rates. Experimental results illustrate that respiration and heartbeat signals can be extracted accurately under different conditions. This noncontact healthcare sensor system proves the commercial feasibility and considerable accessibility of using compact IR-UWB radar for emerging biomedical applications.

  14. 3D positioning scheme exploiting nano-scale IR-UWB orthogonal pulses

    NASA Astrophysics Data System (ADS)

    Kim, Nammoon; Kim, Youngok

    2011-10-01

    In these days, the development of positioning technology for realizing ubiquitous environments has become one of the most important issues. The Global Positioning System (GPS) is a well-known positioning scheme, but it is not suitable for positioning in in-door/building environments because it is difficult to maintain line-of-sight condition between satellites and a GPS receiver. To such problem, various positioning methods such as RFID, WLAN, ZigBee, and Bluetooth have been developed for indoor positioning scheme. However, the majority of positioning schemes are focused on the two-dimension positioning even though three-dimension (3D) positioning information is more useful especially in indoor applications, such as smart space, U-health service, context aware service, etc. In this paper, a 3D positioning system based on mutually orthogonal nano-scale impulse radio ultra-wideband (IR-UWB) signals and cross array antenna is proposed. The proposed scheme uses nano-scale IR-UWB signals providing fine time resolution and high-resolution multiple signal specification algorithm for the time-of-arrival and the angle-of-arrival estimation. The performance is evaluated over various IEEE 802.15.4a channel models, and simulation results show the effectiveness of proposed scheme.

  15. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... information to an associated receiver. The UWB intentional radiator shall cease transmission within 10 seconds... received. An acknowledgment of reception must continue to be received by the UWB intentional radiator...

  16. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... information to an associated receiver. The UWB intentional radiator shall cease transmission within 10 seconds... received. An acknowledgment of reception must continue to be received by the UWB intentional radiator...

  17. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... information to an associated receiver. The UWB intentional radiator shall cease transmission within 10 seconds... received. An acknowledgment of reception must continue to be received by the UWB intentional radiator...

  18. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... information to an associated receiver. The UWB intentional radiator shall cease transmission within 10 seconds... received. An acknowledgment of reception must continue to be received by the UWB intentional radiator...

  19. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... information to an associated receiver. The UWB intentional radiator shall cease transmission within 10 seconds... received. An acknowledgment of reception must continue to be received by the UWB intentional radiator...

  20. Waveform Analysis of UWB GPR Antennas

    PubMed Central

    Rial, Fernando I.; Lorenzo, Henrique; Pereira, Manuel; Armesto, Julia

    2009-01-01

    Ground Penetrating Radar (GPR) systems fall into the category of ultra-wideband (UWB) devices. Most GPR equipment covers a frequency range between an octave and a decade by using short-time pulses. Each signal recorded by a GPR gathers a temporal log of attenuated and distorted versions of these pulses (due to the effect of the propagation medium) plus possible electromagnetic interferences and noise. In order to make a good interpretation of this data and extract the most possible information during processing, a deep knowledge of the wavelet emitted by the antennas is essential. Moreover, some advanced processing techniques require specific knowledge of this signal to obtain satisfactory results. In this work, we carried out a series of tests in order to determine the source wavelet emitted by a ground-coupled antenna with a 500 MHz central frequency. PMID:22573965

  1. UTag: Long-range Ultra-wideband Passive Radio Frequency Tags

    SciTech Connect

    Dowla, F

    2007-03-14

    Long-range, ultra-wideband (UWB), passive radio frequency (RF) tags are key components in Radio Frequency IDentification (RFID) system that will revolutionize inventory control and tracking applications. Unlike conventional, battery-operated (active) RFID tags, LLNL's small UWB tags, called 'UTag', operate at long range (up to 20 meters) in harsh, cluttered environments. Because they are battery-less (that is, passive), they have practically infinite lifetimes without human intervention, and they are lower in cost to manufacture and maintain than active RFID tags. These robust, energy-efficient passive tags are remotely powered by UWB radio signals, which are much more difficult to detect, intercept, and jam than conventional narrowband frequencies. The features of long range, battery-less, and low cost give UTag significant advantage over other existing RFID tags.

  2. Detection of Multiple Stationary Humans Using UWB MIMO Radar

    PubMed Central

    Liang, Fulai; Qi, Fugui; An, Qiang; Lv, Hao; Chen, Fuming; Li, Zhao; Wang, Jianqi

    2016-01-01

    Remarkable progress has been achieved in the detection of single stationary human. However, restricted by the mutual interference of multiple humans (e.g., strong sidelobes of the torsos and the shadow effect), detection and localization of the multiple stationary humans remains a huge challenge. In this paper, ultra-wideband (UWB) multiple-input and multiple-output (MIMO) radar is exploited to improve the detection performance of multiple stationary humans for its multiple sight angles and high-resolution two-dimensional imaging capacity. A signal model of the vital sign considering both bi-static angles and attitude angle of the human body is firstly developed, and then a novel detection method is proposed to detect and localize multiple stationary humans. In this method, preprocessing is firstly implemented to improve the signal-to-noise ratio (SNR) of the vital signs, and then a vital-sign-enhanced imaging algorithm is presented to suppress the environmental clutters and mutual affection of multiple humans. Finally, an automatic detection algorithm including constant false alarm rate (CFAR), morphological filtering and clustering is implemented to improve the detection performance of weak human targets affected by heavy clutters and shadow effect. The simulation and experimental results show that the proposed method can get a high-quality image of multiple humans and we can use it to discriminate and localize multiple adjacent human targets behind brick walls. PMID:27854356

  3. Ultra Wideband (UWB) communication vulnerability for security applications.

    SciTech Connect

    Cooley, H. Timothy

    2010-07-01

    RF toxicity and Information Warfare (IW) are becoming omnipresent posing threats to the protection of nuclear assets, and within theatres of hostility or combat where tactical operation of wireless communication without detection and interception is important and sometimes critical for survival. As a result, a requirement for deployment of many security systems is a highly secure wireless technology manifesting stealth or covert operation suitable for either permanent or tactical deployment where operation without detection or interruption is important The possible use of ultra wideband (UWB) spectrum technology as an alternative physical medium for wireless network communication offers many advantages over conventional narrowband and spread spectrum wireless communication. UWB also known as fast-frequency chirp is nonsinusoidal and sends information directly by transmitting sub-nanosecond pulses without the use of mixing baseband information upon a sinusoidal carrier. Thus UWB sends information using radar-like impulses by spreading its energy thinly over a vast spectrum and can operate at extremely low-power transmission within the noise floor where other forms of RF find it difficult or impossible to operate. As a result UWB offers low probability of detection (LPD), low probability of interception (LPI) as well as anti-jamming (AJ) properties in signal space. This paper analyzes and compares the vulnerability of UWB to narrowband and spread spectrum wireless network communication.

  4. Mobility-Enhanced Reliable Geographical Forwarding in Cognitive Radio Sensor Networks

    PubMed Central

    Zubair, Suleiman; Syed Yusoff, Sharifah Kamilah; Fisal, Norsheila

    2016-01-01

    The emergence of the Internet of Things and the proliferation of mobile wireless devices has brought the area of mobile cognitive radio sensor networks (MCRSN) to the research spot light. Notwithstanding the potentials of CRSNs in terms of opportunistic channel usage for bursty traffic, the effect of the mobility of resource-constrained nodes to route stability, mobility-induced spatio-temporal spectral opportunities and primary user (PU) protection still remain open issues that need to be jointly addressed. To this effect, this paper proposes a mobile reliable geographical forwarding routing (MROR) protocol. MROR provides a robust mobile framework for geographical forwarding that is based on a mobility-induced channel availability model. It presents a comprehensive routing strategy that considers PU activity (to take care of routes that have to be built through PU coverage), PU signal protection (by the introduction of a mobility-induced guard (mguard) distance) and the random mobility-induced spatio-temporal spectrum opportunities (for enhancement of throughput). It also addresses the issue of frequent route maintenance that arises when speeds of the mobile nodes are considered as a routing metric. As a result, simulation has shown the ability of MROR to reduce the route failure rate by about 65% as against other schemes. In addition, further results show that MROR can improve both the throughput and goodput at the sink in an energy-efficient manner that is required in CRSNs as against compared works. PMID:26840312

  5. Mobility-Enhanced Reliable Geographical Forwarding in Cognitive Radio Sensor Networks.

    PubMed

    Zubair, Suleiman; Syed Yusoff, Sharifah Kamilah; Fisal, Norsheila

    2016-01-29

    The emergence of the Internet of Things and the proliferation of mobile wireless devices has brought the area of mobile cognitive radio sensor networks (MCRSN) to the research spot light. Notwithstanding the potentials of CRSNs in terms of opportunistic channel usage for bursty traffic, the effect of the mobility of resource-constrained nodes to route stability, mobility-induced spatio-temporal spectral opportunities and primary user (PU) protection still remain open issues that need to be jointly addressed. To this effect, this paper proposes a mobile reliable geographical forwarding routing (MROR) protocol. MROR provides a robust mobile framework for geographical forwarding that is based on a mobility-induced channel availability model. It presents a comprehensive routing strategy that considers PU activity (to take care of routes that have to be built through PU coverage), PU signal protection (by the introduction of a mobility-induced guard (mguard) distance) and the random mobility-induced spatio-temporal spectrum opportunities (for enhancement of throughput). It also addresses the issue of frequent route maintenance that arises when speeds of the mobile nodes are considered as a routing metric. As a result, simulation has shown the ability of MROR to reduce the route failure rate by about 65% as against other schemes. In addition, further results show that MROR can improve both the throughput and goodput at the sink in an energy-efficient manner that is required in CRSNs as against compared works.

  6. Optimal waveforms design for ultra-wideband impulse radio sensors.

    PubMed

    Li, Bin; Zhou, Zheng; Zou, Weixia; Li, Dejian; Zhao, Chong

    2010-01-01

    Ultra-wideband impulse radio (UWB-IR) sensors should comply entirely with the regulatory spectral limits for elegant coexistence. Under this premise, it is desirable for UWB pulses to improve frequency utilization to guarantee the transmission reliability. Meanwhile, orthogonal waveform division multiple-access (WDMA) is significant to mitigate mutual interferences in UWB sensor networks. Motivated by the considerations, we suggest in this paper a low complexity pulse forming technique, and its efficient implementation on DSP is investigated. The UWB pulse is derived preliminarily with the objective of minimizing the mean square error (MSE) between designed power spectrum density (PSD) and the emission mask. Subsequently, this pulse is iteratively modified until its PSD completely conforms to spectral constraints. The orthogonal restriction is then analyzed and different algorithms have been presented. Simulation demonstrates that our technique can produce UWB waveforms with frequency utilization far surpassing the other existing signals under arbitrary spectral mask conditions. Compared to other orthogonality design schemes, the designed pulses can maintain mutual orthogonality without any penalty on frequency utilization, and hence, are much superior in a WDMA network, especially with synchronization deviations.

  7. Optimal Waveforms Design for Ultra-Wideband Impulse Radio Sensors

    PubMed Central

    Li, Bin; Zhou, Zheng; Zou, Weixia; Li, Dejian; Zhao, Chong

    2010-01-01

    Ultra-wideband impulse radio (UWB-IR) sensors should comply entirely with the regulatory spectral limits for elegant coexistence. Under this premise, it is desirable for UWB pulses to improve frequency utilization to guarantee the transmission reliability. Meanwhile, orthogonal waveform division multiple-access (WDMA) is significant to mitigate mutual interferences in UWB sensor networks. Motivated by the considerations, we suggest in this paper a low complexity pulse forming technique, and its efficient implementation on DSP is investigated. The UWB pulse is derived preliminarily with the objective of minimizing the mean square error (MSE) between designed power spectrum density (PSD) and the emission mask. Subsequently, this pulse is iteratively modified until its PSD completely conforms to spectral constraints. The orthogonal restriction is then analyzed and different algorithms have been presented. Simulation demonstrates that our technique can produce UWB waveforms with frequency utilization far surpassing the other existing signals under arbitrary spectral mask conditions. Compared to other orthogonality design schemes, the designed pulses can maintain mutual orthogonality without any penalty on frequency utilization, and hence, are much superior in a WDMA network, especially with synchronization deviations. PMID:22163511

  8. UWB microwave breast cancer detection: generalized models and performance prediction.

    PubMed

    Chen, Yifan; Gunawan, Erry; Kim, Yongmin; Low, Kay Soon; Soh, Cheong Boon; Thi, Lin Lin

    2006-01-01

    This paper presents a generic framework for the modeling of ultra-wideband (UWB) signal propagation in human breast, which facilitates system-level simulations and provides performance prediction. The clutter associated with the breast tissue heterogeneity is modeled through several key parameters depending on the tissue compositions. Subsequently, important channel properties such as the backscatter energy and the probability density function of time-of-arrival are derived. The modified Hermite polynomials, which fit well into the real pulse shapes, are then used to model the UWB signals. Armed with the channel/signal model preliminaries, three metrics are proposed, namely, the mean clutter response, the clean tumor response, and the worst-case clutter response. The generalized model provides a parsimonious way to study the effects of tissue structures, pulse templates, and array setup on the performance of a specified UWB imaging system. Numerical examples are used to demonstrate the usefulness of the proposed approach.

  9. A Novel UWB Antenna with Dual Band-Notched Characteristics

    NASA Astrophysics Data System (ADS)

    Lin, Yongfan; Liang, Jiangang; Wu, Goucheng; Xu, Zhiyong; Niu, Xuebin

    2015-11-01

    In this article, started from analyzing the basic principle of band-notched characteristics, a feasibly method used for band-notched antenna is demonstrated and the equivalent circuit for this method is designed. A novel UWB antenna is designed. Based on this method, two stubs which can be equivalent to shorted stubs in parallel configuration are added to realize dual band-notched characteristics. Simulated and measured results all show that the UWB antenna yields an impendence bandwidth of 2.0-10.6 GHz by defining VSWR ≦ 2, and two obvious band-notched functions (3.27-3.83 GHz, 4.60-5.90 GHz) occur at the working bandwidth of WIMAX (3.3-3.7 GHz) and HiperLAN/2 (5.15-5.35 GHz, 5.47-5.725 GHz), so the electromagnetic interference between UWB application and WIMAX, HiperLAN/2 can be suppressed.

  10. Spectral efficiency considerations in ultrawideband (UWB) radar and communications

    NASA Astrophysics Data System (ADS)

    Rao, Chinmay; Narayanan, Ram M.

    2005-05-01

    Recent years have seen a rapid expansion of ultrawideband (UWB) technology in radar and communications applications. While the initial impetus for UWB systems was derived from the need for high-resolution radar applications for the military, these systems are now used in a variety of consumer applications such as cellular phones and satellite television. The principal motivation for using UWB is that it offers improved spectral efficiency, i.e., it permits multiple users to occupy and operate within the same frequency band with minimal cross-interference. Currently, UWB schemes use some form of pulse train modulation to encode data onto the carrier. However, these schemes are not always ideal since: (a) these are not the most spectrally efficient due to the fact that additional users can be added by using alternate schemes, (b) these do not possess anti-jam capability since it is possible to estimate the carrier frequency the signal, and (c) such type of modulation possess frequency sidelobes that might interfere with UWB devices in adjacent bands. Our research aims to characterize the above shortcomings and to ultimately develop a method for defining and estimating an appropriate spectral efficiency metric. We also present results of our study of new waveform designs, for both radar and communications, resulting in optimal sharing of frequency segments with minimum impact to system functionality and avoidance of spectral fratricide. One such waveform investigated and described herein is a combination of pulse shape and pulse position modulation, primarily for optimizing the performance of UWB communications systems that use pulse trains.

  11. "Enhanced" Ray Tracing Study of the Attenuation Lanes in Jupiter's Hectometric Radio Emission By Using Cassini Jupiter Encounter Data

    NASA Astrophysics Data System (ADS)

    Imai, M.; Lecacheux, A.

    2014-12-01

    Cassini Jupiter encounter, in the late 2000 and the early 2001, revealed persistent properties of Jovian hectometric (HOM) radiation, which is produced along auroral magnetic field lines in the polar regions of Jupiter. One of the unique properties - known as attenuation lanes (or so-called attenuation bands) - appears as a recurrent, well defined intensity extinction/enhancement feature in the HOM dynamic spectrum. It is believed that this phenomenon is the consequence of ray refraction from high-density medium - either (1) the field-aligned enhanced density along Io plasma torus or (2) Io plasma torus itself or both - in the course of radio propagation from the radio source to the observer. Many studies, mainly on case (1), have used standard ray-tracing technique, which cannot provide reliable information on transmitted radiation intensity. In this study, we have investigated case (2) by using an "enhanced" ray-tracing technique, in which a family of neighboring rays is simultaneously traced, allowing the physical intensity to be estimated along the ray path. We show the results of our ray-tracing computations and then suggest the most plausible scenario for the attenuation lanes phenomenon. More generally and from this example, we conclude that existing refracting plasma structures, encountered by radiation along its ray path through the planetary magnetosphere, might strongly affect, while not taken into account, the overall properties of the radio emission measured by a distant observer.

  12. Enhanced Radio Frequency Biosensor for Food Quality Detection Using Functionalized Carbon Nanofillers.

    PubMed

    Tanguy, Nicolas R; Fiddes, Lindsey K; Yan, Ning

    2015-06-10

    This paper outlines an improved design of inexpensive, wireless and battery free biosensors for in situ monitoring of food quality. This type of device has an additional advantage of being operated remotely. To make the device, a portion of an antenna of a passive 13.56 MHz radio frequency identification (RFID) tag was altered with a sensing element composed of conductive nanofillers/particles, a binding agent, and a polymer matrix. These novel RFID tags were exposed to biogenic amine putrescine, commonly used as a marker for food spoilage, and their response was monitored over time using a general-purpose network analyzer. The effect of conductive filler properties, including conductivity and morphology, and filler functionalization was investigated by preparing sensing composites containing carbon particles (CPs), multiwall carbon nanotubes (MWCNTs), and binding agent grafted-multiwall carbon nanotubes (g-MWCNTs), respectively. During exposure to putrescine, the amount of reflected waves, frequency at resonance, and quality factor of the novel RFID tags decreased in response. The use of MWCNTs reduced tag cutoff time (i.e., faster response time) as compared with the use of CPs, which highlighted the effectiveness of the conductive nanofiller morphology, while the addition of g-MWCNTs further accelerated the sensor response time as a result of localized binding on the conductive nanofiller surface. Microstructural investigation of the film morphology indicated a better dispersion of g-MWCNTs in the sensing composite as compared to MWCNTs and CPs, as well as a smoother texture of the surface of the resulting coating. These results demonstrated that grafting of the binding agent onto the conductive particles in the sensing composite is an effective way to further enhance the detection sensitivity of the RFID tag based sensor.

  13. Enhanced pulsar and single pulse detection via automated radio frequency interference detection in multipixel feeds

    NASA Astrophysics Data System (ADS)

    Kocz, J.; Bailes, M.; Barnes, D.; Burke-Spolaor, S.; Levin, L.

    2012-02-01

    Single pixel feeds on large aperture radio telescopes have the ability to detect weak (˜10 mJy) impulsive bursts of radio emission and sub-mJy radio pulsars. Unfortunately, in large-scale blind surveys, radio frequency interference (RFI) mimics both radio bursts and radio pulsars, greatly reducing the sensitivity to new discoveries as real signals of astronomical origin get lost among the millions of false candidates. In this paper a technique that takes advantage of multipixel feeds to use eigenvector decomposition of common signals is used to greatly facilitate radio burst and pulsar discovery. Since the majority of RFI occurs with zero dispersion, the method was tested on the total power present in the 13 beams of the Parkes multibeam receiver using data from archival intermediate-latitude surveys. The implementation of this method greatly reduced the number of false candidates and led to the discovery of one new rotating radio transient or RRAT, six new pulsars and five new pulses that shared the swept-frequency characteristics similar in nature to the `Lorimer burst'. These five new signals occurred within minutes of 11 previous detections of a similar type. When viewed together, they display temporal characteristics related to integer seconds, with non-random distributions and characteristic 'gaps' between them, suggesting they are not from a naturally occurring source. Despite the success in removing RFI, false candidates present in the data that are only visible after integrating in time or at non-zero dispersion remained. It is demonstrated that with some computational penalty, the method can be applied iteratively at all trial dispersions and time resolutions to remove the vast majority of spurious candidates.

  14. Experimental implant communication of high data rate video using an ultra wideband radio link.

    PubMed

    Chávez-Santiago, Raúl; Balasingham, Ilangko; Bergsland, Jacob; Zahid, Wasim; Takizawa, Kenichi; Miura, Ryu; Li, Huan-Bang

    2013-01-01

    Ultra wideband (UWB) is one of the radio technologies adopted by the IEEE 802.15.6™-2012 standard for on-body communication in body area networks (BANs). However, a number of simulation-based studies suggest the feasibility of using UWB for high data rate implant communication too. This paper presents an experimental verification of said predictions. We carried out radio transmissions of H.264/1280×720 pixels video at 80 Mbps through a UWB multiband orthogonal frequency division multiplexing (MB-OFDM) interface in a porcine chirurgical model. The results demonstrated successful transmission up to a maximum depth of 30 mm in the abdomen and 33 mm in the thorax within the 4.2-4.8 GHz frequency band.

  15. Enhanced tissue integration of implantable electrodes for sensing, and stimulation, via radio frequency glow discharge

    NASA Astrophysics Data System (ADS)

    O'Connor, Laurie M.

    Biopotential electrodes are conductive materials that convert electronic currents to or from ionic currents for sensing, and stimulating specific tissue sites for medical applications. Implanted electrodes become "walled off" by the foreign body tissue reactions producing poorly attached scar capsules dominated by surrounding dense collagenous lamellae and source fibroblasts which are electrically resistive. The conductive interstitial fluid that is typical between an electrode and the resistive capsule allows spurious current paths. The insulating layer increases the distance between the electrode and the target sites and poor attachment often results in electrode migration within the host tissue. This investigation tested the hypothesis that surface-energy modulation of electrodes, via Radio Frequency Glow Discharge Treatment (RFGDT), can improve the performance of tissue-implantable electrodes by reducing the foreign body tissue reaction and enhancing interfacial bonding between the tissue and electrode material. Previously published findings were reproduced in a pilot study of explanted reference grade medical-grade methyl silicone (PDMS) and commercially pure titanium (cpTi) materials and their tissue capsules from 30-day subcutaneous exposures in Balb/C mice. The low-critical surface tension PDMS produced thick, dense, poorly attached scar capsules while the higher-surface-energy commercially pure titanium (cpTi) produced more cellular and strongly attached tissue layers difficult to delaminate from the biomaterial. For the main body of work, cpTi, capacitor-grade Tantalum (Ta), and synthetic heart valve-quality Pyrolytic Carbon (PyC) were evaluated, representative of potential high-surface-energy implant electrode materials. Their surface characteristics were determined as-manufactured and after Radio Frequency Glow Discharge Treatment (RFGDT) by Critical Surface Tension (CST) measurement, Scanning Electron Microscopy (SEM), Energy Dispersive X

  16. A Minimized MIMO-UWB Antenna with High Isolation and Triple Band-Notched Functions

    NASA Astrophysics Data System (ADS)

    Kong, Yuanyuan; Li, Yingsong; Yu, Kai

    2016-11-01

    A compact high isolation MIMO-UWB antenna with triple frequency rejection bands is proposed for UWB communication applications. The proposed MIMO-UWB antenna consists of two identical UWB antennas and each antenna element has a semicircle ring shaped radiation patch fed by a bend microstrip feeding line for covering the UWB band, which operates from 2.85 GHz to 11.79 GHz with an impedance bandwidth of 122.1 %. By etching a L-shaped slot on the ground plane, and embedding an "anchor" shaped stub into the patch and integrating an open ring under the semicircle shaped radiation patch, three notch bands are realized to suppress WiMAX (3.3-3.6 GHz), WLAN(5.725-5.825 GHz) and uplink of X-band satellite (7.9-8.4 GHz) signals. The high isolation with S21<-20 dB in most UWB band is obtained by adding a protruded decoupling structure. The design procedure of the MIMO-UWB antenna is given in detail. The proposed MIMO-UWB antenna is simulated, fabricated and measured. Experimental results demonstrate that the proposed MIMO-UWB antenna has a stable gain, good impedance match, high isolation, low envelope correlation coefficient and good radiation pattern at the UWB operating band and it can provide three designated notch bands.

  17. UWB radar technique for arc detection in coaxial cables and waveguides

    SciTech Connect

    Maggiora, R.; Salvador, S.

    2009-11-26

    As spread spectrum technology has revolutionized the communications industry, Ultra Wide Band (UWB) technology is dramatically improving radar performances. These advanced signal processing techniques have been adapted to coaxial cables and waveguides to provide new features and enhanced performance on arc detection. UWB signals constituted by a sequence of chips (properly chosen to reduce side lobes and to improve detection accuracy) are transmitted along the transmission lines at a specified Pulse Repetition Frequency (PRF) and their echoes are received by means of directional couplers. The core of the receiver is an ultra high-speed correlator implemented in a Digital Signal Processor (DSP). When a target (arc) is detected, its position and its 'radar cross section' are calculated to be able to provide the arc position along the transmission line and to be able to classify the type of detected arc. The 'background scattering' is routinely extracted from the received signal at any pulse. This permits to be resilient to the background structure of transmission lines (bends, junctions, windows, etc.). Thanks to the localization feature, segmentation is also possible for creating sensed and non-sensed zones (for example, to be insensitive to antenna load variations)

  18. Self organization of wireless sensor networks using ultra-wideband radios

    DOEpatents

    Dowla, Farid U.; Nekoogar, Franak; Spiridon, Alex

    2009-06-16

    A novel UWB communications method and system that provides self-organization for wireless sensor networks is introduced. The self-organization is in terms of scalability, power conservation, channel estimation, and node synchronization in wireless sensor networks. The UWB receiver in the present invention adds two new tasks to conventional TR receivers. The two additional units are SNR enhancing unit and timing acquisition and tracking unit.

  19. Trends in ultracool dwarf magnetism. I. X-ray suppression and radio enhancement

    SciTech Connect

    Williams, P. K. G.; Berger, E.; Cook, B. A.

    2014-04-10

    Although ultracool dwarfs (UCDs) are now known to generate and dissipate strong magnetic fields, a clear understanding of the underlying dynamo is still lacking. We have performed X-ray and radio observations of seven UCDs in a narrow range of spectral type (M6.5-M9.5) but spanning a wide range of projected rotational velocities (vsin i ≈ 3-40 km s{sup –1}). We have also analyzed unpublished archival Chandra observations of four additional objects. All of the newly observed targets are detected in the X-ray, while only one is detected in the radio, with the remainder having sensitive upper limits. We present a database of UCDs with both radio and X-ray measurements and consider the data in light of the so-called Güdel-Benz relation (GBR) between magnetic activity in these bands. Some UCDs have very bright radio emission and faint X-ray emission compared to what would be expected for rapid rotators, while others show the opposite behavior. We show that UCDs would still be radio-overluminous relative to the GBR even if their X-ray emission were at standard rapid-rotator 'saturation' levels. Recent results from Zeeman-Doppler imaging and geodynamo simulations suggest that rapidly rotating UCDs may harbor a bistable dynamo that supports either a stronger, axisymmetric magnetic field or a weaker, non-axisymmetric field. We suggest that the data can be explained in a scenario in which strong-field objects obey the GBR while weak-field objects are radio-overluminous and X-ray-underluminous, possibly because of a population of gyrosynchrotron-emitting coronal electrons that is continuously replenished by low-energy reconnection events.

  20. Multi-pulse multi-delay (MPMD) multiple access modulation for UWB

    DOEpatents

    Dowla, Farid U.; Nekoogar, Faranak

    2007-03-20

    A new modulation scheme in UWB communications is introduced. This modulation technique utilizes multiple orthogonal transmitted-reference pulses for UWB channelization. The proposed UWB receiver samples the second order statistical function at both zero and non-zero lags and matches the samples to stored second order statistical functions, thus sampling and matching the shape of second order statistical functions rather than just the shape of the received pulses.

  1. Towards Contactless Silent Speech Recognition Based on Detection of Active and Visible Articulators Using IR-UWB Radar.

    PubMed

    Shin, Young Hoon; Seo, Jiwon

    2016-10-29

    People with hearing or speaking disabilities are deprived of the benefits of conventional speech recognition technology because it is based on acoustic signals. Recent research has focused on silent speech recognition systems that are based on the motions of a speaker's vocal tract and articulators. Because most silent speech recognition systems use contact sensors that are very inconvenient to users or optical systems that are susceptible to environmental interference, a contactless and robust solution is hence required. Toward this objective, this paper presents a series of signal processing algorithms for a contactless silent speech recognition system using an impulse radio ultra-wide band (IR-UWB) radar. The IR-UWB radar is used to remotely and wirelessly detect motions of the lips and jaw. In order to extract the necessary features of lip and jaw motions from the received radar signals, we propose a feature extraction algorithm. The proposed algorithm noticeably improved speech recognition performance compared to the existing algorithm during our word recognition test with five speakers. We also propose a speech activity detection algorithm to automatically select speech segments from continuous input signals. Thus, speech recognition processing is performed only when speech segments are detected. Our testbed consists of commercial off-the-shelf radar products, and the proposed algorithms are readily applicable without designing specialized radar hardware for silent speech processing.

  2. A Detailed Algorithm for Vital Sign Monitoring of a Stationary/Non-Stationary Human through IR-UWB Radar

    PubMed Central

    Khan, Faheem; Cho, Sung Ho

    2017-01-01

    The vital sign monitoring through Impulse Radio Ultra-Wide Band (IR-UWB) radar provides continuous assessment of a patient’s respiration and heart rates in a non-invasive manner. In this paper, IR UWB radar is used for monitoring respiration and the human heart rate. The breathing and heart rate frequencies are extracted from the signal reflected from the human body. A Kalman filter is applied to reduce the measurement noise from the vital signal. An algorithm is presented to separate the heart rate signal from the breathing harmonics. An auto-correlation based technique is applied for detecting random body movements (RBM) during the measurement process. Experiments were performed in different scenarios in order to show the validity of the algorithm. The vital signs were estimated for the signal reflected from the chest, as well as from the back side of the body in different experiments. The results from both scenarios are compared for respiration and heartbeat estimation accuracy. PMID:28165416

  3. Towards Contactless Silent Speech Recognition Based on Detection of Active and Visible Articulators Using IR-UWB Radar

    PubMed Central

    Shin, Young Hoon; Seo, Jiwon

    2016-01-01

    People with hearing or speaking disabilities are deprived of the benefits of conventional speech recognition technology because it is based on acoustic signals. Recent research has focused on silent speech recognition systems that are based on the motions of a speaker’s vocal tract and articulators. Because most silent speech recognition systems use contact sensors that are very inconvenient to users or optical systems that are susceptible to environmental interference, a contactless and robust solution is hence required. Toward this objective, this paper presents a series of signal processing algorithms for a contactless silent speech recognition system using an impulse radio ultra-wide band (IR-UWB) radar. The IR-UWB radar is used to remotely and wirelessly detect motions of the lips and jaw. In order to extract the necessary features of lip and jaw motions from the received radar signals, we propose a feature extraction algorithm. The proposed algorithm noticeably improved speech recognition performance compared to the existing algorithm during our word recognition test with five speakers. We also propose a speech activity detection algorithm to automatically select speech segments from continuous input signals. Thus, speech recognition processing is performed only when speech segments are detected. Our testbed consists of commercial off-the-shelf radar products, and the proposed algorithms are readily applicable without designing specialized radar hardware for silent speech processing. PMID:27801867

  4. A hybrid TOA-fingerprinting based localization of mobile nodes using UWB signaling for Non-line-of-sight conditions.

    PubMed

    Kabir, Md Humayun; Kohno, Ryuji

    2012-01-01

    Recently, Impulse Radio Ultra Wideband (IR-UWB) signaling has become popular for providing precise location accuracy for mobile and wireless sensor node localization in the indoor environment due to its large bandwidth and high time resolution while providing ultra-high transmission capacity. However, the Non-line-of-sight (NLOS) error mitigation has considerable importance in localization of wireless nodes. In order to mitigate NLOS errors in indoor localization this paper proposes and investigates a novel approach which creates a hybrid combination of channel impulse response (CIR)-based fingerprinting (FP) positioning and an iterative Time of Arrival (TOA) real time positioning method using Ultra Wideband (UWB) signaling. Besides, to reduce the calculation complexities in FP method, this paper also introduces a unique idea for the arrangement of reference nodes (or tags) to create a fingerprinting database. The simulation results confirm that the proposed hybrid method yields better positioning accuracies and is much more robust in NLOS error mitigation than TOA only and FP only and a conventional iterative positioning method.

  5. Spectrum-averaged Harmonic Path (SHAPA) algorithm for non-contact vital sign monitoring with ultra-wideband (UWB) radar.

    PubMed

    Van Nguyen; Javaid, Abdul Q; Weitnauer, Mary Ann

    2014-01-01

    We introduce the Spectrum-averaged Harmonic Path (SHAPA) algorithm for estimation of heart rate (HR) and respiration rate (RR) with Impulse Radio Ultrawideband (IR-UWB) radar. Periodic movement of human torso caused by respiration and heart beat induces fundamental frequencies and their harmonics at the respiration and heart rates. IR-UWB enables capture of these spectral components and frequency domain processing enables a low cost implementation. Most existing methods of identifying the fundamental component either in frequency or time domain to estimate the HR and/or RR lead to significant error if the fundamental is distorted or cancelled by interference. The SHAPA algorithm (1) takes advantage of the HR harmonics, where there is less interference, and (2) exploits the information in previous spectra to achieve more reliable and robust estimation of the fundamental frequency in the spectrum under consideration. Example experimental results for HR estimation demonstrate how our algorithm eliminates errors caused by interference and produces 16% to 60% more valid estimates.

  6. A Radio Frequency Electric Current Enhances Antibiotic Efficacy against Bacterial Biofilms

    PubMed Central

    Caubet, R.; Pedarros-Caubet, F.; Chu, M.; Freye, E.; de Belém Rodrigues, M.; Moreau, J. M.; Ellison, W. J.

    2004-01-01

    Bacterial biofilms are notably resistant to antibiotic prophylaxis. The concentration of antibiotic necessary to significantly reduce the number of bacteria in the biofilm matrix can be several hundred times the MIC for the same bacteria in a planktonic phase. It has been observed that the addition of a weak continuous direct electric current to the liquid surrounding the biofilm can dramatically increase the efficacy of the antibiotic. This phenomenon, known as the bioelectric effect, has only been partially elucidated, and it is not certain that the electrical parameters are optimal. We confirm here the bioelectric effect for Escherichia coli biofilms treated with gentamicin and with oxytetracycline, and we report a new bioelectric effect with a radio frequency alternating electric current (10 MHz) instead of the usual direct current. None of the proposed explanations (transport of ions within the biofilm, production of additional biocides by electrolysis, etc.) of the direct current bioelectric effect are applicable to the radio frequency bioelectric effect. We suggest that this new phenomenon may be due to a specific action of the radio frequency electromagnetic field upon the polar parts of the molecules forming the biofilm matrix. PMID:15561841

  7. UWB SAR system PULSAR: new generator and antenna developments

    NASA Astrophysics Data System (ADS)

    Delmonte, Philippe; Dubois, Cyril; Andrieu, Jo"l.; Beillard, Bruno; Lalande, Michèle; Bertrand, Valérie; Jecko, Bernard; Pecastaing, Laurent; Gibert, Alain; Paillol, Jean; Domens, Pierre; Guillerey, Régis; Monnier, Francis; Legoff, Marc

    2003-08-01

    PULSAR is an Ultra Wide-Band short pulse Radar developed by the CELAR (French Technical Centre for Armament Electronics) and the IRCOM (Research Institute of Microwave and Optical Communications) in order to detect foliage and ground concealed targets. One of the most promising mission of such potential radar is the detection of buried and surface land mine fields. An instrumentation measurement system has been designed and implemented. This paper deals with the recent development efforts on this system, specially on a new pulse generator and a new UWB antenna. Recently, the LGE (Laboratoire de Génie Electrique) has developed a high voltage pulse coaxial generator. These recent developments allowed to increase the pulse output voltage and the pulse rise time. The new UWB antenna is able to support a very high voltage; the bandwidth and the gain are greater than the ones of the previous antenna.

  8. Amplify-and-Forward Cooperative Diversity for Green UWB-Based WBSNs

    PubMed Central

    2013-01-01

    This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e − 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs. PMID:24307880

  9. Amplify-and-forward cooperative diversity for green UWB-based WBSNs.

    PubMed

    Shaban, Heba; Abou El-Nasr, Mohamad

    2013-01-01

    This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e - 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs.

  10. Radio Galaxies.

    ERIC Educational Resources Information Center

    Downes, Ann

    1986-01-01

    Provides background information on radio galaxies. Topic areas addressed include: what produces the radio emission; radio telescopes; locating radio galaxies; how distances to radio galaxies are found; physics of radio galaxies; computer simulations of radio galaxies; and the evolution of radio galaxies with cosmic time. (JN)

  11. UWB channel estimation using new generating TR transceivers

    DOEpatents

    Nekoogar, Faranak; Dowla, Farid U.; Spiridon, Alex; Haugen, Peter C.; Benzel, Dave M.

    2011-06-28

    The present invention presents a simple and novel channel estimation scheme for UWB communication systems. As disclosed herein, the present invention maximizes the extraction of information by incorporating a new generation of transmitted-reference (Tr) transceivers that utilize a single reference pulse(s) or a preamble of reference pulses to provide improved channel estimation while offering higher Bit Error Rate (BER) performance and data rates without diluting the transmitter power.

  12. Progress in UWB generation with linear silicon switches

    NASA Astrophysics Data System (ADS)

    Cardwell, Kendall W.; Giorgi, David M.; McIntyre, Iain A.; Solone, Paul J.; Stuurman, K.; Zucker, Oved S. F.

    1993-06-01

    The use of linear photoconductive switches rather than nonlinear switches for the generation of Ultra-Wide-Band (UWB) pulses provides advantages such as jitter-free operation, low losses, and a reduction of the electrical and mechanical stresses in the switch. These advantages lead to the operation of many switches in series and/or parallel, higher average powers and longer lifetimes. Energy Compression Research Corporation (ECR) has demonstrated an advanced UWB source based on light activated silicon switches (LASS). The UWB source consists of a single LASS device mounted on a low impedance (< 0.5 (Omega) ) microstrip transmission line and a high fidelity impedance transformer connected to a 50 (Omega) coaxial connection. The voltage was measured at low impedance and 50 (Omega) to verify the efficiency and fidelity of the impedance transformer. After a transformation of 110:1 in impedance, the measurement at the end of the transformer verified that pulse rise-time was less than 100 ps and the overall efficiency was 50%. The system was tested up to 10 kV into 50 (Omega) before connector breakdown limited further increase. Larger powers can be radiated if the transformer is directly connected to the antenna.

  13. Ultra Wideband (UWB) Synchronous Impulse Reconstruction (SIRE) Radar Upgrade Assessment Field Experiment

    DTIC Science & Technology

    2011-04-01

    Several upgrades have been incorporated into the Ultra Wideband (UWB) Synchronous Impulse Reconstruction (SIRE) radar, which includes: (a) Augmented ... Reality , (b) antenna array mounting structure, (c) electronic switch and electro-mechanical relay, and (d) low noise amplifiers. The purpose of the experiment is to assess UWB SIRE radar upgrades.

  14. Detection of Transionospheric SuperDARN HF Waves by the Radio Receiver Instrument on the enhanced Polar Outflow Probe Satellite

    NASA Astrophysics Data System (ADS)

    Gillies, R. G.; Yau, A. W.; James, H. G.; Hussey, G. C.; McWilliams, K. A.

    2014-12-01

    The enhanced Polar Outflow Probe (ePOP) Canadian small-satellite was launched in September 2013. Included in this suite of eight scientific instruments is the Radio Receiver Instrument (RRI). The RRI has been used to measure VLF and HF radio waves from various ground and spontaneous ionospheric sources. The first dedicated ground transmission that was detected by RRI was from the Saskatoon Super Dual Auroral Radar Network (SuperDARN) radar on Nov. 7, 2013 at 14 MHz. Several other passes over the Saskatoon SuperDARN radar have been recorded since then. Ground transmissions have also been observed from other radars, such as the SPEAR, HAARP, and SURA ionospheric heaters. However, the focus of this study will be on the results obtained from the SuperDARN passes. An analysis of the signal recorded by the RRI provides estimates of signal power, Doppler shift, polarization, absolute time delay, differential mode delay, and angle of arrival. By comparing these parameters to similar parameters derived from ray tracing simulations, ionospheric electron density structures may be detected and measured. Further analysis of the results from the other ground transmitters and future SuperDARN passes will be used to refine these results.

  15. 30 pJ/b, 67 Mbps, Centimeter-to-Meter Range Data Telemetry With an IR-UWB Wireless Link.

    PubMed

    Ebrazeh, Ali; Mohseni, Pedram

    2015-06-01

    This paper reports an energy-efficient, impulse radio ultra wideband (IR-UWB) wireless link operating in 3-5 GHz for data telemetry over centimeter-to-meter range distances at rates extended to tens of Mbps. The link comprises an all-digital, integrated transmitter (TX) fabricated in 90 nm 1P/9M CMOS that incorporates a waveform-synthesis pulse generator and a timing generator for on-off-keying (OOK) pulse modulation and phase scrambling. The link also incorporates an energy-detection receiver (RX) realized with commercial off-the-shelf (COTS) components that performs radio-frequency (RF) filtering, amplification, logarithmic power detection for data demodulation and automatic level control for robust operation in the presence of distance variations. Employing a miniaturized, UWB, chip antenna for the TX and RX, wireless transmission of pseudo-random binary sequence (PRBS) data at rates up to 50 Mbps over 10 cm-1 m is shown. Further, employing a high-gain horn antenna for the RX, wireless transmission of PRBS data at rates up to 67 Mbps over 50 cm-4 m is shown with a TX energy consumption of 30 pJ/b (i.e., power consumption of 2 mW) from 1.2 V. The measured bit error rate (BER) in both cases is < 10(-7) . Results from wireless recording of the background current of a carbon-fiber microelectrode (CFM) in one fast-scan cyclic voltammetry (FSCV) scan using the IR-UWB link are also included, exhibiting excellent match with those obtained from a conventional frequency-shift-keyed (FSK) link at ~433 MHz.

  16. Room temperature radio-frequency plasma-enhanced pulsed laser deposition of ZnO thin films

    NASA Astrophysics Data System (ADS)

    Huang, S.-H.; Chou, Y.-C.; Chou, C.-M.; Hsiao, V. K. S.

    2013-02-01

    In this study, we compared the crystalline structures, optical properties, and surface morphologies of ZnO thin films deposited on silicon and glass substrates by conventional pulsed laser deposition (PLD) and radio-frequency (RF) plasma-enhanced PLD (RF-PEPLD). The depositions were performed at room temperature under 30-100 mTorr pressure conditions. The RF-PEPLD process was found to have deposited a ZnO structure with preferred (0 0 2) c-axis orientation at a higher deposition rate; however, the RF-PEPLD process generated more defects in the thin films. The application of oxygen pressure to the RF-PEPLD process reduced defects effectively and also increased the deposition rate.

  17. Enhancing Community Knowledge and Health Behaviors to Eliminate Blinding Trachoma in Mali Using Radio Messaging as a Strategy

    ERIC Educational Resources Information Center

    Bamani, Sanoussi; Toubali, Emily; Diarra, Sadio; Goita, Seydou; Berte, Zana; Coulibaly, Famolo; Sangare, Hama; Tuinsma, Marjon; Zhang, Yaobi; Dembele, Benoit; Melvin, Palesa; MacArthur, Chad

    2013-01-01

    The National Blindness Prevention Program in Mali has broadcast messages on the radio about trachoma as part of the country's trachoma elimination strategy since 2008. In 2011, a radio impact survey using multi-stage cluster sampling was conducted in the regions of Kayes and Segou to assess radio listening habits, coverage of the broadcasts,…

  18. A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications

    PubMed Central

    Islam, Mohammad Tariqul; Islam, Md. Moinul; Samsuzzaman, Md.; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah

    2015-01-01

    This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator) and CLS (capacitive loaded strip) unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2) covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors. PMID:26007721

  19. A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications.

    PubMed

    Islam, Mohammad Tariqul; Islam, Md Moinul; Samsuzzaman, Md; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah

    2015-05-20

    This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator) and CLS (capacitive loaded strip) unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2) covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors.

  20. Hex-Sided Rounded Dipole Antenna (HSRDA) For UWB Applications

    NASA Astrophysics Data System (ADS)

    Singhal, Sarthak; Verma, Nand Kishor; Singh, Amit Kumar

    2016-03-01

    A hex-sided rounded dipole antenna (HSRDA) for UWB applications is presented. It is designed by the addition of semi-elliptical patch sections at the edges of a square bow-tie antenna. The antenna structure is fed by a modified microstrip feedline for better impedance matching. An impedance bandwidth of 2.9-11.4 GHz is achieved. The antenna structure has quasi omnidirectional radiation patterns and reasonable gain over the same frequency range. A good agreement between the experimental and simulation results is observed. The proposed antenna structure has miniaturized size for the same bandwidth as compared to already reported antenna structures.

  1. Magnetic Zenith Enhancement of HF Radio-Induced Airglow Production at HAARP

    DTIC Science & Technology

    2003-02-22

    frequencies and ionospheric conditions. The spot at HAARP appears on average just equatorward of the nominal magnetic field direction, deflects somewhat...earlier airglow observations at HAARP [Pedersen and Carlson, 2001]. Airglow observations over a wide range of transmitter and ionospheric frequencies...P. A., C. A. Tepley, and L. M. Duncan, Airglow enhancements associated with plasma cavities formed during ionospheric heating ex- periments, J

  2. Interrogation of electrical connector faults using miniaturized UWB sources

    NASA Astrophysics Data System (ADS)

    Tokgöz, Çaǧata; Dardona, Sameh

    2017-01-01

    A diagnostic method for the detection, identification, and characterization of precursors of faults due to partial insertion of pin-socket contacts within electrical connectors commonly used in avionics systems is presented. It is demonstrated that a miniaturized ultrawideband (UWB) source and a minispectrum analyzer can be employed to measure resonant frequency shifts in connector S parameters as a small and low-cost alternative to a large and expensive network analyzer. The transfer function of an electrical connector is represented as a ratio of the spectra measured using the spectrum analyzer with and without the connector. Alternatively, the transfer function is derived in terms of the connector S parameters and the reflection coefficients at both ports of the connector. The transfer function data obtained using this derivation agreed well with its representation as a measured spectral ratio. The derivation enabled the extraction of the connector S parameters from the measured transfer function data as a function of the insertion depth of a pin-socket contact within the connector. In comparison with the S parameters measured directly using a network analyzer at multiple insertion depths, the S parameters extracted from the measured transfer function showed consistent and reliable representation of the electrical connector fault. The results demonstrate the potential of integrating a low-cost miniaturized UWB device into a connector harness for real-time detection of precursors to partially inserted connector faults.

  3. Capacity of UWB wireless channel for neural recording systems.

    PubMed

    El Khaled, Mohamad; Bahrami, Hadi; Fortier, Paul; Gosselin, Benoit; Rusch, Leslie Ann

    2014-01-01

    Ultra wide-band (UWB) short-range communication systems are valuable in medical technology, particularly for implanted devices, due to their low-power consumption, low cost, small size and high data rates. Monitoring of neural responses in the brain requires high data rate if we target a system supporting a large number of sensors. In this work, we are interested in the evaluation of the capacity of the ultra wide-band (UWB) channel that we could exploit using a realistic model of the biological channel. The channel characteristics are examined under two scenarios that are related to TX antenna placements. Using optimal power spectrum allocation (OPSA) at the transmitter side, we have computed this capacity by taking into account the fading characteristics of the channel. The results show the pertinence of the optimal power spectrum allocation for this type of channel. An improvement by a factor of 2 to 3 over a uniform power spectrum allocation (UPSA) when the SNR <; 0 dB was obtained. When the SNR is > 40 dB, both approaches give similar results. Antennas placement is examined under two scenarios having contrasting power constraints.

  4. A UWB Radar Signal Processing Platform for Real-Time Human Respiratory Feature Extraction Based on Four-Segment Linear Waveform Model.

    PubMed

    Hsieh, Chi-Hsuan; Chiu, Yu-Fang; Shen, Yi-Hsiang; Chu, Ta-Shun; Huang, Yuan-Hao

    2016-02-01

    This paper presents an ultra-wideband (UWB) impulse-radio radar signal processing platform used to analyze human respiratory features. Conventional radar systems used in human detection only analyze human respiration rates or the response of a target. However, additional respiratory signal information is available that has not been explored using radar detection. The authors previously proposed a modified raised cosine waveform (MRCW) respiration model and an iterative correlation search algorithm that could acquire additional respiratory features such as the inspiration and expiration speeds, respiration intensity, and respiration holding ratio. To realize real-time respiratory feature extraction by using the proposed UWB signal processing platform, this paper proposes a new four-segment linear waveform (FSLW) respiration model. This model offers a superior fit to the measured respiration signal compared with the MRCW model and decreases the computational complexity of feature extraction. In addition, an early-terminated iterative correlation search algorithm is presented, substantially decreasing the computational complexity and yielding negligible performance degradation. These extracted features can be considered the compressed signals used to decrease the amount of data storage required for use in long-term medical monitoring systems and can also be used in clinical diagnosis. The proposed respiratory feature extraction algorithm was designed and implemented using the proposed UWB radar signal processing platform including a radar front-end chip and an FPGA chip. The proposed radar system can detect human respiration rates at 0.1 to 1 Hz and facilitates the real-time analysis of the respiratory features of each respiration period.

  5. Inter-BSs virtual private network for privacy and security enhanced 60 GHz radio-over-fiber system

    NASA Astrophysics Data System (ADS)

    Zhang, Chongfu; Chen, Chen; Zhang, Wei; Jin, Wei; Qiu, Kun; Li, Changchun; Jiang, Ning

    2013-06-01

    A novel inter-basestations (inter-BSs) based virtual private network (VPN) for the privacy and security enhanced 60 GHz radio-over-fiber (RoF) system using optical code-division multiplexing (OCDM) is proposed and demonstrated experimentally. By establishing inter-BSs VPN overlaying the network structure of a 60 GHz RoF system, the express and private paths for the communication of end-users under different BSs can be offered. In order to effectively establish the inter-BSs VPN, the OCDM encoding/decoding technology is employed in the RoF system. In each BS, a 58 GHz millimeter-wave (MMW) is used as the inter-BSs VPN channel, while a 60 GHz MMW is used as the common central station (CS)-BSs communication channel. The optical carriers used for the downlink, uplink and VPN link transmissions are all simultaneously generated in a lightwave-centralized CS, by utilizing four-wave mixing (FWM) effect in a semiconductor optical amplifier (SOA). The obtained results properly verify the feasibility of our proposed configuration of the inter-BSs VPN in the 60 GHz RoF system.

  6. In vitro enhancement of SAOS-2 cell calcified matrix deposition onto radio frequency magnetron sputtered bioglass-coated titanium scaffolds.

    PubMed

    Saino, Enrica; Maliardi, Valentina; Quartarone, Eliana; Fassina, Lorenzo; Benedetti, Laura; De Angelis, Maria Gabriella Cusella; Mustarelli, Piercarlo; Facchini, Alessandro; Visai, Livia

    2010-03-01

    In bone tissue engineering, bioglass coating of titanium (Ti) scaffolds has drawn attention as a method to improve osteointegration and implant fixation. In this in vitro study, bioactive glass layers with an approximate thickness of 1 microm were deposited at 200 degrees C onto a three-dimensional Ti-6Al-4V scaffold using a radio frequency (r.f.) magnetron sputtering system. After incubation with SAOS-2 human osteoblasts, in comparison with the uncoated scaffolds, the bioglass-coated scaffolds showed a twofold increase in cell proliferation (p < 0.05) up to 68.4 x 10(6), and enhanced the deposition of extracellular matrix components such as decorin, fibronectin, osteocalcin, osteonectin, osteopontin, and type-I and -III collagens (p < 0.05). Calcium deposition was twofold greater on the bioglass-coated scaffolds (p < 0.05). The immunofluorescence related to the preceding bone matrix proteins and calcium showed their colocalization to the cell-rich areas. Alkaline phosphatase activity increased twofold (p < 0.001) and its protein content was threefold higher with respect to the uncoated sample. Quantitative reverse transcriptase-polymerase chain reaction analysis revealed upregulated transcription specific for type-I collagen and osteopontin (p < 0.001). All together, these results demonstrate that the bioglass coating of the three-dimensional Ti scaffolds by the r.f. magnetron sputtering technique determines an in vitro increase of the bone matrix elaboration and may potentially have a clinical benefit.

  7. Undoped InOx films deposited by radio frequency plasma enhanced reactive thermal evaporation at room temperature: importance of substrate.

    PubMed

    Parreira, P; Lavareda, G; Valente, J; Nunes, F T; Amaral, A; de Carvalho, C Nunes

    2010-04-01

    Conductive and transparent undoped thin films of indium oxide (InOx ), 120 nm average thick, were deposited by radio frequency plasma enhanced reactive thermal evaporation (rf-PERTE) of indium in the presence of oxygen at room temperature. Several substrates were used in order to study their influence on the main properties of these films: alkali free (AF) glass, fused silica, crystalline silicon and polyethylene terephthalate (PET). Surface morphology of the InOx films as a function of the substrates was observed by SEM and showed that the undoped InOx films obtained are nanostructured. For the c-Si substrate, InOx films with increased grain size are obtained, induced by the crystalline substrate. Films deposited on fused silica and AF glass substrates show a nano-grainy surface with similar surface morphologies. The InOx films deposited on AF glass show the highest values of both: electrical conductivity of about 1100 (omega cm)(-1) and visible transmittance of 85%. The substrate has a greater influence on the surface morphology of the films when a polymer (PET) is used. InOx films deposited on PET show a decrease in the electrical conductivity (90 (omega cm)(-1)) and a slight decrease in the average visible transmittance (78%).

  8. 79 GHz UWB automotive short range radar - Spectrum allocation and technology trends

    NASA Astrophysics Data System (ADS)

    Bloecher, H.-L.; Sailer, A.; Rollmann, G.; Dickmann, J.

    2009-05-01

    Automotive UWB (Ultra-Wideband) short range radar (SSR) is on the market as a key technology for novel comfort and safety systems. SiGe based 79 GHz UWB SRR will be a definite candidate for the long term substitution of the 24 GHz UWB SRR. This paper will give an overview of the finished BMBF joint project KOKON and the recently started successing project RoCC, which concentrate on the development of this technology and sensor demonstrators. In both projects, the responsibilities of Daimler AG deal with application based sensor specification, test and evaluation of realized sensor demonstrators. Recent UWB SRR frequency regulation approaches and activitites will be introduced. Furthermore, some first results of Daimler activities within RoCC will be presented, dealing with the packaging and operation of these sensors within the complex car environment.

  9. A High-Voltage UWB Coupled-Line Directional Coupler for Radar

    NASA Astrophysics Data System (ADS)

    Farr, Everett G.; Atchley, Lanney M.; Ellibee, Donald E.; Lawry, Dean I.

    The simplest method of building ultra-wideband (UWB) radar systems requires two antennas, one each for transmission and reception. To save space, it would be preferable to use a single antenna, so a UWB, high-voltage directional coupler is needed. In support of that goal, we develop here coupled-line directional couplers. We begin by describing the time-domain theory of operation of such couplers, and we optimize the impedances for maximum return signal. We then design, build and test two versions of high-voltage coupled-line directional couplers. We incorporate the directional couplers into a low-voltage UWB radar system, and we observe scattering back from a comer reflector. We identify possible improvements to the directional couplers and the UWB radar system.

  10. Enhanced MUF propagation of HF radio waves in the auroral zone

    NASA Astrophysics Data System (ADS)

    Milan, S. E.; Jones, T. B.; Warrington, E. M.

    1997-01-01

    Four high frequency propagation paths were monitored from a transmitter located within the polar cap by four receivers located variously within the polar cap and at sub-auroral latitudes. Of these paths, one was contained entirely within the polar cap at all times, two were trans-auroral at all times, and one varied from trans-auroral during the day to polar cap during the night. Fourteen frequencies within the HF band were transmitted each hour for the duration of two 24 day experimental campaigns during the summer of 1988 and the winter of 1989. From an analysis of the received signals the confidence of signal recognition and signal strength were determined. During geomagnetically undisturbed periods the propagation behaviour resembled that of mid-latitude paths. During geomagnetically disturbed times, however, night-time propagation occurred on frequencies up to and sometimes over 10 MHz above the undisturbed night-time MUF, for periods of 2 to 6 h. These features appeared on the trans-auroral paths only and were attributed to E region (and occasionally F region) enhancement by auroral precipitation. APEs (auroral E propagation events) occurred on over 50% of nights. The occurrence of APEs also coincided with ionospheric storm periods when the HF band available for propagation was otherwise significantly narrowed due to a depletion of the F region electron density.

  11. Enhancing community knowledge and health behaviors to eliminate blinding trachoma in Mali using radio messaging as a strategy.

    PubMed

    Bamani, Sanoussi; Toubali, Emily; Diarra, Sadio; Goita, Seydou; Berté, Zana; Coulibaly, Famolo; Sangaré, Hama; Tuinsma, Marjon; Zhang, Yaobi; Dembelé, Benoit; Melvin, Palesa; MacArthur, Chad

    2013-04-01

    The National Blindness Prevention Program in Mali has broadcast messages on the radio about trachoma as part of the country's trachoma elimination strategy since 2008. In 2011, a radio impact survey using multi-stage cluster sampling was conducted in the regions of Kayes and Segou to assess radio listening habits, coverage of the broadcasts, community knowledge and behavior specific to trachoma and facial cleanliness of children. Radio access and listening were high, with 60% of respondents having heard a message on the radio about trachoma. The majority of respondents knew about trachoma, its root causes, its impact on health and prevention measures. Additionally, 66% reported washing their children's faces more than or equal to twice/day and 94% reported latrine disposal of feces. A high percentage of persons who gave a positive response to knowledge and behavior questions reported hearing the trachoma messages on the radio with 60% reporting that the radio is where they learned about trachoma. There was no significant difference in facial cleanliness when comparing children whose primary caregiver had/had not heard the trachoma messages. Next steps include revising the current messages to include more focused behavior change messaging and to engage in a more robust use of community radios.

  12. Time-Reversal Based Range Extension technique for Ultra-wideband (UWB) Sensors and Applications in Tactical Communications and Networking

    DTIC Science & Technology

    2010-01-28

    DISTRIBUTION /AVAILABILITY STATEMENT release for public distribution . 13. SUPPLEMENTARY NOTES 14. ABSTRACT This final report summarizes major project...Communication System 57 4.2.4 Simulation Results 59 4.2.5 Conclusions 61 4.3 Publication List 62 III Technical Impacts 65 4.4 UWB MIMO ...Testbed 67 4.4.1 2-By-l UWB MISO Testbed Description 67 4.4.2 Potential UWB MIMO Testbed 67 CONTENTS 7 5 Waveform Diveristy 69 6 Wideband

  13. Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices

    SciTech Connect

    Wang, Tong

    2002-09-18

    Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radiofrequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish an optimized process to minimize or eliminate EFE. To achieve these goals, a scanning field emission microscope (SFEM) was designed and built as an extension to an existing commercial scanning electron microscope (SEM). In the SFEM chamber of ultra high vacuum, a sample is moved laterally in a raster pattern under a high voltage anode tip for EFE detection and localization. The sample is then transferred under vacuum to the SEM chamber equipped with an energy-dispersive x-ray spectrometer for individual emitting site characterization. Compared to other systems built for similar purposes, this apparatus has low cost and maintenance, high operational flexibility, considerably bigger scan area, as well as reliable performance. EFE sources from planar Nb have been studied after various surface preparation, including chemical etching and electropolishing, combined with ultrasonic or high-pressure water rinse. Emitters have been identified, analyzed and the preparation process has been examined and improved based on EFE results. As a result, field-emission-free or near field-emission-free surfaces at ~140 MV/m have been consistently achieved with the above techniques. Characterization on the remaining emitters leads to the conclusion that no evidence of intrinsic emitters, i.e., no fundamental electric field limit induced by EFE, has been observed up to ~140 MV/m. Chemically etched and electropolished Nb are compared and no significant difference is observed up to ~140 MV/m. To

  14. Deceptive jamming for countering UWB-SAR based on Doppler frequency phase template of false target

    NASA Astrophysics Data System (ADS)

    He, Xiaodong; Tang, Bin

    2016-04-01

    A false target deceptive jamming method for countering ultra-wideband synthetic aperture radar (UWB-SAR) is proposed in this paper, which is based on dechirp processing to intercepted UWB-SAR signal and inverse dechirp to jamming signal. The jammer quadrature down-converts and dechirps the intercepted UWB-SAR signal using a linear frequency modulation (LFM) signal oscillator, which could reduce the bandwidth and sample rate of analog-to-digital converter. Then, the jammer utilises the azimuth direction Doppler frequency phase between the false target and the jammer, and backward reflection coefficient template to modulate the phase of the intercepted UWB-SAR signal, and then delayed the modulated phase and also modulated the range direction Doppler frequency phase to the that. Finally, the jammer uses LFM signal oscillator to up-convert the narrowband jamming signal in order to recover the bandwidth of the signal. Parameter errors analysis and simulation results have shown that the detected parameters and motion characteristic errors reduce the resolution and offset the expected position of the false target, but it still could obtain an expected false target image. Theoretical analysis and simulation results indicated that the jamming signal proposed in this paper could produce a false target in the UWB-SAR image, which provide a feasible method for countering UWB-SAR in real time.

  15. Design and Performance Evaluation of a UWB Communication and Tracking System for Mini-AERCam

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2005-01-01

    be a passive component of the communication system which will need to operate in a time-varying multipath environment created as the robot camera moves over the ISS structure. In addition, due to many interference sources located on the ISS, SSO, LEO satellites and ground-based transmitters, selecting a frequency for the ISS and Mini-AERCam link which will coexist with all interferers poses a major design challenge. To meet all of these challenges, ultrawideband (UWB) radio technology is being studied for use in the Mini-AERCam communication and tracking subsystem. The research described in this report is focused on design and evaluation of passive tracking system algorithms based on UWB radio transmissions from mini-AERCam.

  16. Transmission over UWB channels with OFDM system using LDPC coding

    NASA Astrophysics Data System (ADS)

    Dziwoki, Grzegorz; Kucharczyk, Marcin; Sulek, Wojciech

    2009-06-01

    Hostile wireless environment requires use of sophisticated signal processing methods. The paper concerns on Ultra Wideband (UWB) transmission over Personal Area Networks (PAN) including MB-OFDM specification of physical layer. In presented work the transmission system with OFDM modulation was connected with LDPC encoder/decoder. Additionally the frame and bit error rate (FER and BER) of the system was decreased using results from the LDPC decoder in a kind of turbo equalization algorithm for better channel estimation. Computational block using evolutionary strategy, from genetic algorithms family, was also used in presented system. It was placed after SPA (Sum-Product Algorithm) decoder and is conditionally turned on in the decoding process. The result is increased effectiveness of the whole system, especially lower FER. The system was tested with two types of LDPC codes, depending on type of parity check matrices: randomly generated and constructed deterministically, optimized for practical decoder architecture implemented in the FPGA device.

  17. Very compact quad band-notched UWB monopole antenna

    NASA Astrophysics Data System (ADS)

    Wu, Ling; Xia, Yingqing; Ye, Lei; Li, Lingzhi

    2016-10-01

    A very compact UWB antenna with four notched bands is proposed. The antenna consists of a rectangular radiating patch with a half circle at bottom, a tapered microstrip feed-line, and a semielliptical ground plane. With a pair of Lshaped slots, complementary co-directional SRR on the patch and a pair of L-shaped slots on the ground plane, four notched bands are created to prevent interference from WiMAX /WLAN/X-band. Experimental results show that the designed antenna, with compact size 20×30mm2, has an operating band(VSWR<2) from 2.7 to 20GHz,except four stop bands of 3.1 3.7GHz, 5.13 5.48GHz, 5.74 6.04GHz, 7.3 7.96GHz. And good radiation patterns within the operating band have been observed.

  18. A Novel Triangular Shaped UWB Fractal Antenna Using Circular Slot

    NASA Astrophysics Data System (ADS)

    Shahu, Babu Lal; Pal, Srikanta; Chattoraj, Neela

    2016-03-01

    The article presents the design of triangular shaped fractal based antenna with circular slot for ultra wideband (UWB) application. The antenna is fed using microstrip line and has overall dimension of 24×24×1.6 mm3. The proposed antenna is covering the wide frequency bandwidth of 2.99-11.16 GHz and is achieved using simple fractal based triangular-circular geometries and asymmetrical ground plane. The antenna is designed and parametrical studies are performed using method of moment (MOM) based Full Wave Electromagnetic (EM) software Simulator Zeland IE3D. The prototype of proposed antenna is fabricated and tested to compare the simulated and measured results of various antenna parameters. The antenna has good impedance bandwidth, nearly constant gain and stable radiation pattern. Measured return loss shows fair agreement with simulated one. Also measured group delay variation obtained is less than 1.0 ns, which proves good time domain behavior of the proposed antenna.

  19. Non-Invasive UWB Sensing of Astronauts' Breathing Activity

    PubMed Central

    Baldi, Marco; Cerri, Graziano; Chiaraluce, Franco; Eusebi, Lorenzo; Russo, Paola

    2015-01-01

    The use of a UWB system for sensing breathing activity of astronauts must account for many critical issues specific to the space environment. The aim of this paper is twofold. The first concerns the definition of design constraints about the pulse amplitude and waveform to transmit, as well as the immunity requirements of the receiver. The second issue concerns the assessment of the procedures and the characteristics of the algorithms to use for signal processing to retrieve the breathing frequency and respiration waveform. The algorithm has to work correctly in the presence of surrounding electromagnetic noise due to other sources in the environment. The highly reflecting walls increase the difficulty of the problem and the hostile scenario has to be accurately characterized. Examples of signal processing techniques able to recover breathing frequency in significant and realistic situations are shown and discussed. PMID:25558995

  20. Non-invasive UWB sensing of astronauts' breathing activity.

    PubMed

    Baldi, Marco; Cerri, Graziano; Chiaraluce, Franco; Eusebi, Lorenzo; Russo, Paola

    2014-12-30

    The use of a UWB system for sensing breathing activity of astronauts must account for many critical issues specific to the space environment. The aim of this paper is twofold. The first concerns the definition of design constraints about the pulse amplitude and waveform to transmit, as well as the immunity requirements of the receiver. The second issue concerns the assessment of the procedures and the characteristics of the algorithms to use for signal processing to retrieve the breathing frequency and respiration waveform. The algorithm has to work correctly in the presence of surrounding electromagnetic noise due to other sources in the environment. The highly reflecting walls increase the difficulty of the problem and the hostile scenario has to be accurately characterized. Examples of signal processing techniques able to recover breathing frequency in significant and realistic situations are shown and discussed.

  1. Through-wall imaging and characterization of human activity using ultrawideband (UWB) random noise radar

    NASA Astrophysics Data System (ADS)

    Lai, Chieh-Ping; Narayanan, Ram M.

    2005-05-01

    Recent terrorist activities and law-enforcement situations involving hostage situations underscore the need for effective through-wall imaging. Current building interior imaging systems are based on short-pulse waveforms, which require specially designed antennas to subdue unwanted ringing. In addition, periodically transmitted pulses of energy are easily recognizable by the intelligent adversary who may employ appropriate countermeasures to confound detection. A coherent polarimetric random noise radar architecture is being developed based on UWB technology and software defined radio, which has great promise in its ability to covertly image obscured targets. The main advantages of the random noise radar lie in two aspects: first, random noise waveform has an ideal "thumbtack" ambiguity function, i.e., its down range and cross range resolution can be separately controlled, thus providing unambiguous high resolution imaging at any distance; second, random noise waveform is inherently low probability of intercept (LPI) and low probability of detection (LPD), i.e., it is immune from detection, jamming, and interference. Thus, it is an ideal candidate sensor for covert imaging of obscured regions in hostile environments. The coherency in the system can be exploited to field a fully-polarimetric system that can take advantage of polarization features in target recognition. Moving personnel can also be detected using Doppler processing. Simulation studies are used to analyze backscattered signals from the walls, and humans and other targets behind the walls. Real-time data processing shows human activity behind the wall and human target tracking. The high resolution provides excellent multipath and clutter rejection.

  2. Dramatic radio enhancement from the 26th anniversary outburst of jet-driving symbiotic binary MWC 560

    NASA Astrophysics Data System (ADS)

    Lucy, Adrian B.; Weston, J. H. S.; Sokoloski, J. L.

    2016-04-01

    We report the first detection of radio emission from the reputedly jet-driving symbiotic star MWC 560, which is currently undergoing a multi-wavelength outburst (ATel #8653, #8832, and references therein).

  3. Performance Evaluation of a UWB-RFID System for Potential Space Applications

    NASA Technical Reports Server (NTRS)

    Phan, Chan T.; Arndt, D.; Ngo, P.; Gross, J.; Ni, Jianjun; Rafford, Melinda

    2006-01-01

    This talk presents a brief overview of the ultra-wideband (UWB) RFID system with emphasis on the performance evaluation of a commercially available UWB-RFID system. There are many RFID systems available today, but many provide just basic identification for auditing and inventory tracking. For applications that require high precision real time tracking, UWB technology has been shown to be a viable solution. The use of extremely short bursts of RF pulses offers high immunity to interference from other RF systems, precise tracking due to sub-nanosecond time resolution, and robust performance in multipath environments. The UWB-RFID system Sapphire DART (Digital Active RFID & Tracking) will be introduced in this talk. Laboratory testing using Sapphire DART is performed to evaluate its capability such as coverage area, accuracy, ease of operation, and robustness. Performance evaluation of this system in an operational environment (a receiving warehouse) for inventory tracking is also conducted. Concepts of using the UWB-RFID technology to track astronauts and assets are being proposed for space exploration.

  4. All-optical UWB doublet pulses generation by using a delay interferometer

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Xu, En-Ming

    2013-06-01

    We demonstrated a simple scheme to generate ultra wideband (UWB) doublet pulses by inputting a dark return-to-zero (RZ) signal into a fiber delay interferometer (FDI). An 0.625-Gbit/s dark-RZ pulse train where the pulse width is 120 ps was inputted into a FDI where the free spectral range (FSR) is 0.16 nm (˜20 GHz, according time delay is ˜50 ps) and the extinction ratio (ER) is 9 dB, and the phase difference of the two fiber arms was changed and controlled by adjusting the operation temperature of the FDI, by do so, UWB doublet pulses were directly generated at an output port of the FDI. The system parameter effects on the output UWB pulses were discussed. Moreover, we also numerically demonstrated that the UWB quadruplet pulses can be generated in the same set by optimizing system parameters. This scheme has some distinct advantages including easy integration, convenient tuning, good stability, and so on. Presented method also accords with the general features in future applied UWB-Over-Fiber communication system, such as, single optical source input, simple configuration and passive device.

  5. e-POP Radio Science Using Amateur Radio Transmissions

    NASA Astrophysics Data System (ADS)

    Frissell, N. A.; Perry, G. W.; Miller, E. S.; Shovkoplyas, A.; Moses, M. L.; James, H. G.; Yau, A. W.

    2015-12-01

    A major component of the enhanced Polar Outflow Probe (e-POP) Radio Receiver Instrument (RRI) mission is to utilize artificially generated radio emissions to study High Frequency (HF) radio wave propagation in the ionosphere. In the North American and European sectors, communications between amateur radio operators are a persistent and abundant source source of HF transmissions. We present the results of HF radio wave propagation experiments using amateur radio transmissions as an HF source for e-POP RRI. We detail how a distributed and autonomously operated amateur radio network can be leveraged to study HF radio wave propagation as well as the structuring and dynamics of the ionosphere over a large geographic region. In one case, the sudden disappearance of nearly two-dozen amateur radio HF sources located in the midwestern United States was used to detect a enhancement in foF2 in that same region. We compare our results to those from other more conventional radio instruments and models of the ionosphere to demonstrate the scientific merit of incorporating amateur radio networks for radio science at HF.

  6. Implementation of Software Programmable Radios to Form Ad-Hoc Meshed Networks to Enhance Maritime Interception Operations

    DTIC Science & Technology

    2010-09-01

    Networks, Software Programmable Radios, MIMO , Ultra-wideband, MIO, VBSS 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18...locations where it was never possible before: in crowded urban environments, massive buildings, subway tunnels, - virtually anywhere.  Networks can be...Multiple Input / Multiple Output ( MIMO )  Network-Controlled Robotics (Unmanned Vehicles) 2. Possible Combination of TW220 and Small Satellites Software

  7. Modeling, Real-Time Estimation, and Identification of UWB Indoor Wireless Channels

    DOE PAGES

    Olama, Mohammed M.; Djouadi, Seddik M.; Li, Yanyan; ...

    2013-01-01

    Stochastic differential equations (SDEs) are used to model ultrawideband (UWB) indoor wireless channels. We show that the impulse responses for time-varying indoor wireless channels can be approximated in a mean-square sense as close as desired by impulse responses that can be realized by SDEs. The state variables represent the inphase and quadrature components of the UWB channel. The expected maximization and extended Kalman filter are employed to recursively identify and estimate the channel parameters and states, respectively, from online received signal strength measured data. Both resolvable and nonresolvable multipath received signals are considered and represented as small-scaled Nakagami fading. Themore » proposed models together with the estimation algorithm are tested using UWB indoor measurement data demonstrating the method’s viability and the results are presented.« less

  8. Modeling, Real-Time Estimation, and Identification of UWB Indoor Wireless Channels

    SciTech Connect

    Olama, Mohammed M; Djouadi, Seddik M; Li, Yanyan; Fathy, Aly

    2013-01-01

    In this paper, stochastic differential equations (SDEs) are used to model ultrawideband (UWB) indoor wireless channels. We show that the impulse responses for time-varying indoor wireless channels can be approximated in a mean square sense as close as desired by impulse responses that can be realized by SDEs. The state variables represent the inphase and quadrature components of the UWB channel. The expected maximization and extended Kalman filter are employed to recursively identify and estimate the channel parameters and states, respectively, from online received signal strength measured data. Both resolvable and non-resolvable multipath received signals are considered and represented as small-scaled Nakagami fading. The proposed models together with the estimation algorithm are tested using UWB indoor measurement data demonstrating the method s viability and the results are presented.

  9. Smart container UWB sensor system for situational awareness of intrusion alarms

    DOEpatents

    Romero, Carlos E.; Haugen, Peter C.; Zumstein, James M.; Leach, Jr., Richard R.; Vigars, Mark L.

    2013-06-11

    An in-container monitoring sensor system is based on an UWB radar intrusion detector positioned in a container and having a range gate set to the farthest wall of the container from the detector. Multipath reflections within the container make every point on or in the container appear to be at the range gate, allowing intrusion detection anywhere in the container. The system also includes other sensors to provide false alarm discrimination, and may include other sensors to monitor other parameters, e.g. radiation. The sensor system also includes a control subsystem for controlling system operation. Communications and information extraction capability may also be included. A method of detecting intrusion into a container uses UWB radar, and may also include false alarm discrimination. A secure container has an UWB based monitoring system

  10. Performance of Multiple Pulse Multiple Delay Modulated UWB Signals in a Multiple Access Indoor Wireless Channel

    SciTech Connect

    Nekoogar, F

    2003-06-12

    In this paper, the performance of a two user UWB multiple access (UWB-MA) system based on multiple-pulse multiple-delay (MPMD) modulation scheme in an indoor wireless channel is evaluated by computer simulations. The indoor multipath propagation channel model used in this study is based on the modified statistical Saleh-Valenzuela model proposed by Foerester and Li from Intel. The simulation results indicate that the multipath performance of MPMD modulated signals in a multiple access system outperforms the nonmultipath case as the number of autocorrelation function (ACF) sampling points increases for each user. This is an unusual but important result, since MPMD receiver exploits multipath phenomenon in indoor wireless channels to increase the BER performance, hence the transmission rate in a UWB-MA system.

  11. UWB based low-cost and non-invasive practical breast cancer early detection

    NASA Astrophysics Data System (ADS)

    Vijayasarveswari, V.; Khatun, S.; Fakir, M. M.; Jusoh, M.; Ali, S.

    2017-03-01

    Breast cancer is one of the main causes of women death worldwide. Breast tumor is an early stage of cancer that locates in cells of a human breast. As there is no remedy, early detection is crucial. Towards this, Ultra-Wideband (UWB) is a prominent candidate. It is a wireless communication technology which can achieve high bandwidth with low power utilization. UWB is suitable to be used for short range communication systems including breast cancer detection since it is secure, non-invasive and human health friendly. This paper presents the low-cost and non-invasive early breast cancer detection strategy using UWB sensor (or antenna). Emphasis is given here to detect breast tumor in 2D and 3D environments. The developed system consisted of hardware and software. Hardware included UWB transceiver and a pair of home-made directional sensor/antenna. The software included feed-forward back propagation Neural Network (NN) module to detect the tumor existence, size and location along with soft interface between software and hardware. Forward scattering technique was used by placing two sensors diagonally opposite sides of a breast phantom. UWB pulses were transmitted from one side of phantom and received from other side, controlled by the software interface in PC environment. Collected received signals were then fed into the NN module for training, testing and validation. The system exhibited detection efficiency on tumor existence, location (x, y, z), and size were approximately 100%, (78.17%, 70.66%, 92.46%), 85.86% respectively. The proposed UWB based early breast cancer detection system could be more practical with low-cost, user friendly and non-harmful features. This project may help users to monitor their breast health regularly at their home.

  12. Breakdown Behavior of a Wireless Communication Network Under UWB Impact

    NASA Astrophysics Data System (ADS)

    Rohe, M.; Koch, M.

    Systems with high priority to safety and reliability such as monitoring systems on airports have to work properly. Fast information transmission, continuous access to databases, as well as the management of air traffic are most important for effective and safe operation. Sources of Intentional Electromagnetic Interference can be manufactured relatively easy using commercially available components by civilian persons with relevant expertise and can be used for sabotage or blackmail purposes. For analyzing the weak points of a system existing on airports, it is necessary to reproduce its setup. In this investigation a UHF transmitter of a wireless communication device is developed and its breakdown behavior to unipolar fast rise pulses (UWB) is determined. A breakdown is a non-permanent damage, but includes a type of upset, that requires manual reset or at least stops communications for some period of time. The transmitter consists of three main components connected by data cables: power supply, microcontroller, and loop antenna. The immunity tests are accomplished as a function of the electromagnetic field direction to the device using an open TEM waveguide.

  13. Reconfigurable UWB Bandpass Filter with Flexible Notch Characteristics

    NASA Astrophysics Data System (ADS)

    Dhwaj, Kirti

    The thesis reports a compact tunable ultra-wideband (UWB) notch filter using hybrid microstrip and coplanar waveguide (CPW) structure. The tunable notch is implemented to filter out the wireless local area network (WLAN) channels from 5GHz to 6GHz. The proposed structure utilizes the resonance of open ended stubs to achieve transmission zeroes in the filter passband. Varactors and by-pass capacitors are then introduced for dynamic tunability of notch. Further, the electromagnetic decoupling of the two resonators leads to tunable bandwidth of notch. DC bias circuitry is implemented to control the varactor capacitances. Rejection levels up to 25 dB are attained using this technique while maintaining insertion loss levels below 2.5 dB in the passband. The reconfigurability of bandwidth is shown by maintaining a constant bandwidth of 150 MHz across the WLAN band for the notch. The filter achieves an excellent wide bandwidth (from 2.5 GHz to 8.5 GHz) using multimode-resonator (MMR) based topology which makes the filter one wavelength long at the central frequency.

  14. UWB multi-burst transmit driver for averaging receivers

    DOEpatents

    Dallum, Gregory E

    2012-11-20

    A multi-burst transmitter for ultra-wideband (UWB) communication systems generates a sequence of precisely spaced RF bursts from a single trigger event. There are two oscillators in the transmitter circuit, a gated burst rate oscillator and a gated RF burst or RF power output oscillator. The burst rate oscillator produces a relatively low frequency, i.e., MHz, square wave output for a selected transmit cycle, and drives the RF burst oscillator, which produces RF bursts of much higher frequency, i.e., GHz, during the transmit cycle. The frequency of the burst rate oscillator sets the spacing of the RF burst packets. The first oscillator output passes through a bias driver to the second oscillator. The bias driver conditions, e.g., level shifts, the signal from the first oscillator for input into the second oscillator, and also controls the length of each RF burst. A trigger pulse actuates a timing circuit, formed of a flip-flop and associated reset time delay circuit, that controls the operation of the first oscillator, i.e., how long it oscillates (which defines the transmit cycle).

  15. Statistical Modeling of Indirect Paths for UWB Sensors in an Indoor Environment

    PubMed Central

    Lee, Moona; Lee, Joon-Yong

    2016-01-01

    In this paper, we present a statistical model of an indirect path generated in an ultra-wideband (UWB) human tracking scenario. When performing moving target detection, an indirect path signal can generate ghost targets that may cause a false alarm. For this purpose, we performed radar measurements in an indoor environment and established a statistical model of an indirect path based on the measurement data. The proposed model takes the form of a modified Saleh–Valenzuela model, which is used in a UWB channel model. An application example of the proposed model for mitigating false alarms is also presented. PMID:28035978

  16. Breast tumor detection using UWB circular-SAR tomographic microwave imaging.

    PubMed

    Oloumi, Daniel; Boulanger, Pierre; Kordzadeh, Atefeh; Rambabu, Karumudi

    2015-01-01

    This paper describes the possibility of detecting tumors in human breast using ultra-wideband (UWB) circular synthetic aperture radar (CSAR). CSAR is a subset of SAR which is a radar imaging technique using a circular data acquisition pattern. Tomographic image reconstruction is done using a time domain global back projection technique adapted to CSAR. Experiments are conducted on a breast phantoms made of pork fat emulating normal and cancerous conditions. Preliminary experimental results show that microwave imaging of a breast phantom using UWB-CSAR is a simple and low-cost method, efficiently capable of detecting the presence of tumors.

  17. Super multi-channel recording systems with UWB wireless transmitter for BMI.

    PubMed

    Suzuki, Takafumi; Ando, Hiroshi; Yoshida, Takeshi; Sawahata, Hirohito; Kawasaki, Keisuke; Hasegawa, Isao; Matsushita, Kojiro; Hirata, Masayuki; Yoshimine, Toshiki; Takizawa, Kenichi

    2014-01-01

    In order to realize a low-invasive and high accuracy Brain-Machine Interface (BMI) system for clinical applications, a super multi-channel recording system was developed in which 4096 channels of Electrocorticogram (ECoG) signal can be amplified and transmitted to outside the body by using an Ultra Wide Band (UWB) wireless system. Also, a high density, flexible electrode array made by using a Parylene-C substrate was developed that is composed of units of 32-ch recording arrays. We have succeeded in an evaluation test of UWB wireless transmitting using a body phantom system.

  18. Radio Days.

    ERIC Educational Resources Information Center

    Sanderson, Neil

    1998-01-01

    Thousands of today's high school students run FM radio stations at school, carrying on a tradition that began 50 years ago. Radio helps students learn to work with others and develop a strong sense of responsibility. A sidebar gives advice on starting a high school radio station. (MLF)

  19. Ultrawideband Electromagnetic Interference to Aircraft Radios: Results of Limited Functional Testing With United Airlines and Eagles Wings Incorporated, in Victorville, California

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Shaver, Timothy W.; Fuller, Gerald L.

    2002-01-01

    On February 14, 2002, the FCC adopted a FIRST REPORT AND ORDER, released it on April 22, 2002, and on May 16, 2002 published in the Federal Register a Final Rule, permitting marketing and operation of new products incorporating UWB technology. Wireless product developers are working to rapidly bring this versatile, powerful and expectedly inexpensive technology into numerous consumer wireless devices. Past studies addressing the potential for passenger-carried portable electronic devices (PEDs) to interfere with aircraft electronic systems suggest that UWB transmitters may pose a significant threat to aircraft communication and navigation radio receivers. NASA, United Airlines and Eagles Wings Incorporated have performed preliminary testing that clearly shows the potential for handheld UWB transmitters to cause cockpit failure indications for the air traffic control radio beacon system (ATCRBS), blanking of aircraft on the traffic alert and collision avoidance system (TCAS) displays, and cause erratic motion and failure of instrument landing system (ILS) localizer and glideslope pointers on the pilot horizontal situation and attitude director displays. This report provides details of the preliminary testing and recommends further assessment of aircraft systems for susceptibility to UWB electromagnetic interference.

  20. Impulse radio ultra wideband wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry.

    PubMed

    Ebrazeh, Ali; Bozorgzadeh, Bardia; Mohseni, Pedram

    2015-01-01

    This paper demonstrates the feasibility of utilizing impulse radio ultra wideband (IR-UWB) signaling technique for reliable, wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM) to address the problem of elevated data rates in high-channel-count neurochemical monitoring. Utilizing an FSCV-sensing chip fabricated in AMS 0.35μm 2P/4M CMOS, a 3-5-GHz, IR-UWB transceiver (TRX) chip fabricated in TSMC 90nm 1P/9M RF CMOS, and two off-chip, miniature, UWB antennae, wireless transfer of pseudo-random binary sequence (PRBS) data at 50Mbps over a distance of <;1m is first shown with bit-error rates (BER) <; 10(-3). Further, IR-UWB wireless transmission of dopamine concentration levels prerecorded with FSCV at a CFM during flow injection analysis (FIA) is also demonstrated with transmitter (TX) power dissipation of only ~4.4μW from 1.2V, representing two orders of magnitude reduction in TX power consumption compared to that of a conventional frequency-shift-keyed (FSK) link operating at ~433MHz.

  1. Ultra-wideband radios for time-of-flight-ranging and network position estimation

    DOEpatents

    Hertzog, Claudia A.; Dowla, Farid U.; Dallum, Gregory E.; Romero, Carlos E.

    2011-06-14

    This invention provides a novel high-accuracy indoor ranging device that uses ultra-wideband (UWB) RF pulsing with low-power and low-cost electronics. A unique of the present invention is that it exploits multiple measurements in time and space for very accurate ranging. The wideband radio signals utilized herein are particularly suited to ranging in harsh RF environments because they allow signal reconstruction in spite of multipath propagation distortion. Furthermore, the ranging and positioning techniques discussed herein directly address many of the known technical challenges encountered in UWB localization regarding synchronization and sampling. In the method developed, noisy, corrupted signals can be recovered by repeating range measurements across a channel, and the distance measurements are combined from many locations surrounding the target in a way that minimizes the range biases associated to indirect flight paths and through-wall propagation delays.

  2. Low-Rank Matrix Recovery Approach for Clutter Rejection in Real-Time IR-UWB Radar-Based Moving Target Detection

    PubMed Central

    Sabushimike, Donatien; Na, Seung You; Kim, Jin Young; Bui, Ngoc Nam; Seo, Kyung Sik; Kim, Gil Gyeom

    2016-01-01

    The detection of a moving target using an IR-UWB Radar involves the core task of separating the waves reflected by the static background and by the moving target. This paper investigates the capacity of the low-rank and sparse matrix decomposition approach to separate the background and the foreground in the trend of UWB Radar-based moving target detection. Robust PCA models are criticized for being batched-data-oriented, which makes them inconvenient in realistic environments where frames need to be processed as they are recorded in real time. In this paper, a novel method based on overlapping-windows processing is proposed to cope with online processing. The method consists of processing a small batch of frames which will be continually updated without changing its size as new frames are captured. We prove that RPCA (via its Inexact Augmented Lagrange Multiplier (IALM) model) can successfully separate the two subspaces, which enhances the accuracy of target detection. The overlapping-windows processing method converges on the optimal solution with its batch counterpart (i.e., processing batched data with RPCA), and both methods prove the robustness and efficiency of the RPCA over the classic PCA and the commonly used exponential averaging method. PMID:27598159

  3. Low-Rank Matrix Recovery Approach for Clutter Rejection in Real-Time IR-UWB Radar-Based Moving Target Detection.

    PubMed

    Sabushimike, Donatien; Na, Seung You; Kim, Jin Young; Bui, Ngoc Nam; Seo, Kyung Sik; Kim, Gil Gyeom

    2016-09-01

    The detection of a moving target using an IR-UWB Radar involves the core task of separating the waves reflected by the static background and by the moving target. This paper investigates the capacity of the low-rank and sparse matrix decomposition approach to separate the background and the foreground in the trend of UWB Radar-based moving target detection. Robust PCA models are criticized for being batched-data-oriented, which makes them inconvenient in realistic environments where frames need to be processed as they are recorded in real time. In this paper, a novel method based on overlapping-windows processing is proposed to cope with online processing. The method consists of processing a small batch of frames which will be continually updated without changing its size as new frames are captured. We prove that RPCA (via its Inexact Augmented Lagrange Multiplier (IALM) model) can successfully separate the two subspaces, which enhances the accuracy of target detection. The overlapping-windows processing method converges on the optimal solution with its batch counterpart (i.e., processing batched data with RPCA), and both methods prove the robustness and efficiency of the RPCA over the classic PCA and the commonly used exponential averaging method.

  4. The enhanced locating performance of an integrated cross-correlation and genetic algorithm for radio monitoring systems.

    PubMed

    Chang, Yao-Tang; Wu, Chi-Lin; Cheng, Hsu-Chih

    2014-04-24

    The rapid development of wireless broadband communication technology has affected the location accuracy of worldwide radio monitoring stations that employ time-difference-of-arrival (TDOA) location technology. In this study, TDOA-based location technology was implemented in Taiwan for the first time according to International Telecommunications Union Radiocommunication (ITU-R) recommendations regarding monitoring and location applications. To improve location accuracy, various scenarios, such as a three-dimensional environment (considering an unequal locating antenna configuration), were investigated. Subsequently, the proposed integrated cross-correlation and genetic algorithm was evaluated in the metropolitan area of Tainan. The results indicated that the location accuracy at a circular error probability of 50% was less than 60 m when a multipath effect was present in the area. Moreover, compared with hyperbolic algorithms that have been applied in conventional TDOA-based location systems, the proposed algorithm yielded 17-fold and 19-fold improvements in the mean difference when the location position of the interference station was favorable and unfavorable, respectively. Hence, the various forms of radio interference, such as low transmission power, burst and weak signals, and metropolitan interference, was proved to be easily identified, located, and removed.

  5. The Enhanced Locating Performance of an Integrated Cross-Correlation and Genetic Algorithm for Radio Monitoring Systems

    PubMed Central

    Chang, Yao-Tang; Wu, Chi-Lin; Cheng, Hsu-Chih

    2014-01-01

    The rapid development of wireless broadband communication technology has affected the location accuracy of worldwide radio monitoring stations that employ time-difference-of-arrival (TDOA) location technology. In this study, TDOA-based location technology was implemented in Taiwan for the first time according to International Telecommunications Union Radiocommunication (ITU-R) recommendations regarding monitoring and location applications. To improve location accuracy, various scenarios, such as a three-dimensional environment (considering an unequal locating antenna configuration), were investigated. Subsequently, the proposed integrated cross-correlation and genetic algorithm was evaluated in the metropolitan area of Tainan. The results indicated that the location accuracy at a circular error probability of 50% was less than 60 m when a multipath effect was present in the area. Moreover, compared with hyperbolic algorithms that have been applied in conventional TDOA-based location systems, the proposed algorithm yielded 17-fold and 19-fold improvements in the mean difference when the location position of the interference station was favorable and unfavorable, respectively. Hence, the various forms of radio interference, such as low transmission power, burst and weak signals, and metropolitan interference, was proved to be easily identified, located, and removed. PMID:24763254

  6. Studies of scattering, reflectivity, and transmitivity in WBAN channel: feasibility of using UWB.

    PubMed

    Kabir, Md Humaun; Ashrafuzzaman, Kazi; Chowdhury, M Sanaullah; Kwak, Kyung Sup

    2010-01-01

    The Wireless Personal Area Network (WPAN) is one of the fledging paradigms that the next generation of wireless systems is sprouting towards. Among them, a more specific category is the Wireless Body Area Network (WBAN) used for health monitoring. On the other hand, Ultra-Wideband (UWB) comes with a number of desirable features at the physical layer for wireless communications. One big challenge in adoption of UWB in WBAN is the fact that signals get attenuated exponentially. Due to the intrinsic structural complexity in human body, electromagnetic waves show a profound variation during propagation through it. The reflection and transmission coefficients of human body are highly dependent upon the dielectric constants as well as upon the frequency. The difference in structural materials such as fat, muscles and blood essentially makes electromagnetic wave attenuation to be different along the way. Thus, a complete characterization of body channel is a challenging task. The connection between attenuation and frequency of the signal makes the investigation of UWB in WBAN an interesting proposition. In this paper, we study analytically the impact of body channels on electromagnetic signal propagation with reference to UWB. In the process, scattering, reflectivity and transmitivity have been addressed with analysis of approximate layer-wise modeling, and with numerical depictions. Pulses with Gaussian profile have been employed in our analysis. It shows that, under reasonable practical approximations, the human body channel can be modeled in layers so as to have the effects of total reflections or total transmissions in certain frequency bands. This could help decide such design issues as antenna characteristics of implant devices for WBAN employing UWB.

  7. Nanotube Radio

    NASA Astrophysics Data System (ADS)

    Jensen, Kenneth; Weldon, Jeff; Garcia, Henry; Zettl, Alex

    2008-03-01

    We have constructed a fully functional, fully integrated radio receiver from a single carbon nanotube. The nanotube serves simultaneously as all essential components of a radio: antenna, tunable band-pass filter, amplifier, and demodulator. A direct current voltage source, as supplied by a battery, powers the radio. Using carrier waves in the commercially relevant 40-400 MHz range and both frequency and amplitude modulation techniques, we demonstrate successful music and voice reception.

  8. Radio Science

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Radio science experiments use electromagnetic waves to probe or study the solar system. Three major research areas were identified within this discipline: radio astronomy, radar astronomy, and celestial mechanics. Radio astronomy (or radiometry) is the detection and measurement of naturally produced radio frequency emissions. Sources include surfaces, atmospheres, rings, and plasmas. Radar astronomy is the observation of man-made signals after their interaction with a target. Both imaging and non-imaging results. Celestial mechanics includes all studies related to the motions of (and gravity fields of) bodies within the solar system. These should not be considered rigid separations, but aid in the discussion of the data sets.

  9. Inhibition of cellular proliferation and enhancement of hydrogen peroxide production in fibrosarcoma cell line by weak radio frequency magnetic fields.

    PubMed

    Castello, Pablo R; Hill, Iain; Sivo, Frank; Portelli, Lucas; Barnes, Frank; Usselman, Robert; Martino, Carlos F

    2014-12-01

    This study presents experimental data for the effects of weak radio frequency (RF) magnetic fields on hydrogen peroxide (H2O2) production and cellular growth rates of fibrosarcoma HT1080 cells in vitro. Cells were exposed either to 45 µT static magnetic fields (SMFs)-oriented vertical to the plane of growth or to SMFs combined with weak 5 and 10 MHz RF magnetic fields of 10 µTRMS intensity perpendicular to the static field. Cell numbers were reduced up to 30% on Day 2 for the cells exposed to the combination of SMF and a 10 MHz RF magnetic field compared with the SMF control cells. In addition, cells exposed to 10 MHz RF magnetic fields for 8 h increased H2O2 production by 55%. The results demonstrate an overall magnetic field-induced biological effect that shows elevated H2O2 levels with accompanying decrease in cellular growth rates.

  10. The effect of oxygen flow rate and radio frequency plasma power on cubic ZnMgO ultraviolet sensors grown by plasma-enhanced molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Casey Boutwell, R.; Wei, Ming; Schoenfeld, Winston V.

    2013-07-01

    Cubic Zn1-xMgxO thin films were produced by Plasma-Enhanced Molecular Beam Epitaxy. Oxygen flow rate and applied Radio-Frequency (RF) plasma power were varied to investigate the impact on film growth and optoelectronic device performance. Solar-blind and visible-blind detectors were fabricated with metal-semiconductor-metal interdigitated Ni/Mg/Au contacts and responsivity is compared under different growth conditions. Increasing oxygen flow rate and RF plasma power increased Zn incorporation in the film, which leads to phase segregation at relatively high Zn/Mg ratio. Responsivity as high as 61 A/W was measured in phase-segregated ZnMgO visible-blind detectors.

  11. Hybrid radio-frequency/direct-current plasma-enhanced chemical vapor deposition system for deposition on inner surfaces of polyethylene terephthalate bottles

    SciTech Connect

    Li Jing; Gong Chunzhi; Yang Shiqin; Tian Xiubo; Fu, Ricky K. Y.; Chu, Paul K.

    2009-12-15

    A hybrid radio-frequency (rf)/direct-current (dc) system has been developed to control the biasing effects during deposition of diamondlike carbon (DLC) films onto the inner wall of polyethylene terephthalate (PET) bottles. An additional dc bias is coupled to the rf electrode to produce the effect of equivalent rf self-biasing. This allows more flexible control of the deposition of the DLC films which are intended to improve the gas barrier characteristics. The experimental results demonstrate that the additional dc bias improves the adhesion strength between the DLC film and PET, although the enhancement in the gas barrier properties is not significantly larger compared to the one without dc bias. The apparatus and methodology have practical importance in the food and beverage industry.

  12. College Radio.

    ERIC Educational Resources Information Center

    Sauls, Samuel J.

    As with commercial stations, the underlying premise of the college radio station is to serve the community, whether it be the campus community or the community at large, but in unique ways often geared to underserved niches of the population. Much of college radio's charm lies in its unpredictable nature and constant mutations. The stations give…

  13. Radio astronomy

    NASA Technical Reports Server (NTRS)

    Taylor, R. M.; Manchester, R. N.

    1980-01-01

    The activities of the Deep Space Network in support of radio and radar astronomy operations during July and August 1980 are reported. A brief update on the OSS-sponsored planetary radio astronomy experiment is provided. Also included are two updates, one each from Spain and Australia on current host country activities.

  14. Radio stars.

    PubMed

    Hjellming, R M; Wade, C M

    1971-09-17

    Up to the present time six classes of radio stars have been established. The signals are almost always very faint and drastically variable. Hence their discovery has owed as much to serendipity as to the highly sophisticated equipment and techniques that have been used. When the variations are regular, as with the pulsars, this characteristic can be exploited very successfully in the search for new objects as well as in the detailed study of those that are already known. The detection of the most erratically variable radio stars, the flare stars and the x-ray stars, is primarily a matter of luck and patience. In the case of the novas, one at least knows where and oughly when to look for radio emission. A very sensitive interferometer is clearly the best instrument to use in the initial detection of a radio star. The fact that weak background sources are frequently present makes it essential to prove that the position of a radio source agrees with that of a star to within a few arc seconds. The potential of radio astronomy for the study of radio stars will not be realized until more powerful instruments than those that are available today can be utilized. So far, we have been able to see only the most luminous of the radio stars.

  15. A RF receiver frontend for SC-UWB in a 0.18-μm CMOS process

    NASA Astrophysics Data System (ADS)

    Rui, Guo; Haiying, Zhang

    2012-12-01

    A radio frequency (RF) receiver frontend for single-carrier ultra-wideband (SC-UWB) is presented. The front end employs direct-conversion architecture, and consists of a differential low noise amplifier (LNA), a quadrature mixer, and two intermediate frequency (IF) amplifiers. The proposed LNA employs source inductively degenerated topology. First, the expression of input impedance matching bandwidth in terms of gate-source capacitance, resonant frequency and target S11 is given. Then, a noise figure optimization strategy under gain and power constraints is proposed, with consideration of the integrated gate inductor, the bond-wire inductance, and its variation. The LNA utilizes two stages with different resonant frequencies to acquire flat gain over the 7.1-8.1 GHz frequency band, and has two gain modes to obtain a higher receiver dynamic range. The mixer uses a double balanced Gilbert structure. The front end is fabricated in a TSMC 0.18-μm RF CMOS process and occupies an area of 1.43 mm2. In high and low gain modes, the measured maximum conversion gain are 42 dB and 22 dB, input 1 dB compression points are -40 dBm and -20 dBm, and S11 is better than -18 dB and -14.5 dB. The 3 dB IF bandwidth is more than 500 MHz. The double sideband noise figure is 4.7 dB in high gain mode. The total power consumption is 65 mW from a 1.8 V supply.

  16. Investigation of the State and Uses of Ultra-Wide-Band Radio-Frequency Identification Technology

    SciTech Connect

    Hickerson, Jonathan W; Younkin, James R

    2010-01-01

    Radio-frequency identification (RFID) technology has revolutionized the concept of asset tracking. By affixing an RFID tag to a valued asset, one can track the item throughout any facility where RIFD readers are in place, thereby alerting inspectors to theft, misuse, and misplacement of the tracked item. While not yet implemented for tracking very high value assets, RFID technology is already widely used in many industries as the standard for asset tracking. A subset of RFID technology exists called Ultra-Wide-Band (UWB) RFID. While traditional (sometimes called narrow-band) RFID technology transmits a continuous sine-wave signal of a narrow frequency range, UWB technology works by transmitting signals as short pulses of a broad frequency range. This improves performance in several areas, namely, range, precision, and accuracy of motion detection. Because of the nature of the technology, it also performs well in close proximity to metal, which sets it apart from traditional RFID. The purpose of this paper is to investigate the current state of UWB RFID technology and research the areas where it already is being used. This is accomplished through study of publicly known uses of the technology as well as personal exploration of RFID hardware and software. This paper presents the findings in a general manner to facilitate their usefulness for diverse applications.

  17. Enhanced EJ Cell Killing of 125I Radiation by Combining with Cytosine Deaminase Gene Therapy Regulated by Synthetic Radio-Responsive Promoter

    PubMed Central

    Li, Ling; Kang, Lei; Wang, Rong-Fu; Yan, Ping; Zhao, Qian; Yin, Lei; Guo, Feng-qin

    2015-01-01

    Abstract Aim: To investigate the enhancing effect of radionuclide therapy by the therapeutic gene placed under the control of radio-responsive promoter. Methods: The recombinant lentivirus E8-codA-GFP, including a synthetic radiation-sensitive promoter E8, cytosine deaminase (CD) gene, and green fluorescent protein gene, was constructed. The gene expression activated by 125I radiation was assessed by observation of green fluorescence. The ability of converting 5-fluorocytosine (5-FC) to 5-fluorourial (5-FU) by CD enzyme was assessed by high-performance liquid chromatography. The viability of the infected cells exposed to 125I in the presence of 5-FC was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the infected cells exposed to 125I alone served as negative control and 5-FU as positive control. Results: The recombinant lentiviral vector was constructed successfully. On exposure of infected cells to 125I, green fluorescence can be observed and 5-FU can be detected. MTT assay showed that the survival rate for infected cells treated with 125I was lower compared with the 125I control group, but higher than the positive control group. Conclusion: The synthetic promoter E8 can induce the expression of downstream CD gene under 125I radiation, and the tumor killing effect of 125I can be enhanced by combining CD gene therapy with radiosensitive promoter. PMID:26382009

  18. Enhancement of the mechanical properties of AZ31 magnesium alloy via nanostructured hydroxyapatite thin films fabricated via radio-frequency magnetron sputtering.

    PubMed

    Surmeneva, M A; Tyurin, A I; Mukhametkaliyev, T M; Pirozhkova, T S; Shuvarin, I A; Syrtanov, M S; Surmenev, R A

    2015-06-01

    The structure, composition and morphology of a radio-frequency (RF) magnetron sputter-deposited dense nano-hydroxyapatite (HA) coating that was deposited on the surface of an AZ31 magnesium alloy were characterized using AFM, SEM, EDX and XRD. The results obtained from SEM and XRD experiments revealed that the bias applied during the deposition of the HA coating resulted in a decrease in the grain and crystallite size of the film having a crucial role in enhancing the mechanical properties of the fabricated biocomposites. A maximum hardness of 9.04 GPa was found for the HA coating, which was prepared using a bias of -50 V. The hardness of the HA film deposited on the grounded substrate (GS) was found to be 4.9 GPa. The elastic strain to failure (H/E) and the plastic deformation resistance (H(3)/E(2)) for an indentation depth of 50 nm for the HA coating fabricated at a bias of -50 V was found to increase by ~30% and ~74%, respectively, compared with the coating deposited at the GS holder. The nanoindentation tests demonstrated that all of the HA coatings increased the surface hardness on both the microscale and the nanoscale. Therefore, the results revealed that the films deposited on the surface of the AZ31 magnesium alloy at a negative substrate bias can significantly enhance the wear resistance of this resorbable alloy.

  19. Ultra Wide Band (UWB) Interference - Assessment and Mitigation Studies

    DTIC Science & Technology

    2006-02-01

    Gaussian pulses............................................................................ 45 Figure 35 ESD of Hermite polynomial based (from...television stations have to have a license to operate. Their carrier frequency is allocated based upon which channels are already assigned in the nearby...continuous sine wave, as shown in Figure 1, where its frequency is based on how many times it completes a cycle in one second. In the AM radio band

  20. Novel Dual-band Slot Antenna Design for Bluetooth and UWB Applications

    NASA Astrophysics Data System (ADS)

    Huang, Hai-Yan; Shao, Wei; Wang, Bing-Zhong; Ma, Xiao-Liang

    2014-05-01

    A novel technique to introduce an additional low frequency band to compact ultra wideband (UWB) slot antennas is proposed in this paper. To get an additional Bluetooth band, a parasitic strip is mounted on the back side of the slot edge. Because of the interaction of the strip and the slot edge, the Bluetooth band can be obtained while a notch band between the Bluetooth band and UWB band also appears. Two types of feeding, coplanar waveguide and microstrip line, are investigated. The proposed antennas are both fabricated on a low-cost FR4 substrate and have compact size (24 mm × 28 mm × 1 mm). The good agreement between measured and simulated results verifies our design.

  1. Super-resolution techniques for velocity estimation using UWB random noise radar signals

    NASA Astrophysics Data System (ADS)

    Dawood, Muhammad; Quraishi, Nafish; Alejos, Ana V.

    2011-06-01

    The Doppler spread pertaining to the ultrawideband (UWB) radar signals from moving target is directly proportional to the bandwidth of the transmitted signal and the target velocity. Using typical FFT-based methods, the estimation of true velocities pertaining to two targets moving with relatively close velocities within a radar range bin is problematic. In this paper, we extend the Multiple Signal Classification (MUSIC) algorithm to resolve targets moving velocities closer to each other within a given range bin for UWB random noise radar waveforms. Simulated and experimental results are compared for various target velocities using both narrowband (200MHz) and wideband (1GHz) noise radar signals, clearly establishing the unbiased and unambiguous velocity estimations using the MUSIC algorithm.

  2. Emerging Communication Technologies (ECT) Phase 2 Report. Volume 3; Ultra Wideband (UWB) Technology

    NASA Technical Reports Server (NTRS)

    Bastin, Gary L.; Harris, William G.; Chiodini, Robert; Nelson, Richard A.; Huang, PoTien; Kruhm, David A.

    2003-01-01

    The Emerging Communication Technology (ECT) project investigated three First Mile communication technologies in support of NASA s Second Generation Reusable Launch Vehicle (2nd Gen RLV), Orbital Space Plane, Advanced Range Technology Working Group (ARTWG) and the Advanced Spaceport Technology Working Group (ASTWG). These First Mile technologies have the purpose of interconnecting mobile users with existing Range Communication infrastructures. ECT was a continuation of the Range Information System Management (RISM) task started in 2002. RISM identified the three advance communication technologies investigated under ECT. These were Wireless Ethernet (Wi-Fi), Free Space Optics (FSO), and Ultra Wideband (UWB). Due to the report s size, it has been broken into three volumes: 1) Main Report 2) Appendices 3) UWB

  3. Multichannel neural recording with a 128 Mbps UWB wireless transmitter for implantable brain-machine interfaces.

    PubMed

    Ando, H; Takizawa, K; Yoshida, T; Matsushita, K; Hirata, M; Suzuki, T

    2015-01-01

    To realize a low-invasive and high accuracy BMI (Brain-machine interface) system, we have already developed a fully-implantable wireless BMI system which consists of ECoG neural electrode arrays, neural recording ASICs, a Wi-Fi based wireless data transmitter and a wireless power receiver with a rechargeable battery. For accurate estimation of movement intentions, it is important for a BMI system to have a large number of recording channels. In this paper, we report a new multi-channel BMI system which is able to record up to 4096-ch ECoG data by multiple connections of 64-ch ASICs and time division multiplexing of recorded data. This system has an ultra-wide-band (UWB) wireless unit for transmitting the recorded neural signals to outside the body. By preliminary experiments with a human body equivalent liquid phantom, we confirmed 4096-ch UWB wireless data transmission at 128 Mbps mode below 20 mm distance.

  4. Radio Pulsars

    NASA Astrophysics Data System (ADS)

    Beskin, V. S.; Chernov, S. V.; Gwinn, C. R.; Tchekhovskoy, A. A.

    2015-10-01

    Almost 50 years after radio pulsars were discovered in 1967, our understanding of these objects remains incomplete. On the one hand, within a few years it became clear that neutron star rotation gives rise to the extremely stable sequence of radio pulses, that the kinetic energy of rotation provides the reservoir of energy, and that electromagnetic fields are the braking mechanism. On the other hand, no consensus regarding the mechanism of coherent radio emission or the conversion of electromagnetic energy to particle energy yet exists. In this review, we report on three aspects of pulsar structure that have seen recent progress: the self-consistent theory of the magnetosphere of an oblique magnetic rotator; the location, geometry, and optics of radio emission; and evolution of the angle between spin and magnetic axes. These allow us to take the next step in understanding the physical nature of the pulsar activity.

  5. Performances study of UWB monopole antennas using half-elliptic radiator conformed on elliptical surface

    NASA Astrophysics Data System (ADS)

    Djidel, S.; Bouamar, M.; Khedrouche, D.

    2016-04-01

    This paper presents a performances study of UWB monopole antenna using half-elliptic radiator conformed on elliptical surface. The proposed antenna, simulated using microwave studio computer CST and High frequency simulator structure HFSS, is designed to operate in frequency interval over 3.1 to 40 GHz. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest. The proposed antenna structure is suitable for ultra-wideband applications, which is, required for many wearable electronics applications.

  6. A Rugged Ultra-Wideband (UWB) Circular Planar Monopole for Multichannel Radar

    DTIC Science & Technology

    2016-03-01

    where y is the half separation distance between the tapered edges, x is the length, and p is the exponential growth parameter that governs how...quickly or how slowly the tapered slot expands.11 If the exponential growth is too large or too small, then the voltage standing wave ratio (VSWR) can...the standard exponentially tapered Vivaldi antenna and contrasts the size and performance to the UWB-CPM using a simulated example Vivaldi. The

  7. Implementation and Performance Analysis of Noncoherent UWB Transceiver Under LOS Residential Channel Environment

    NASA Astrophysics Data System (ADS)

    Choi, Sungsoo; Koo, Insoo; Kim, Youngsun

    This paper focuses on two things. One is to describe implementation of a Low-Rate Ultra-Wideband (LR-UWB) transceiver for low power Wireless Personal Area Network (WPAN) applications. The other is to derive the Bit Error Rate (BER) performance of the proposed system. At first, in order to implement low-power and low-complexity transceiver, we design a non-coherent On-Off-Keying(OOK) UWB system by adopting the architecture of the simplified asynchronous transmission and the edge-triggered pulse transmission, which makes the system performance independent of the shape of the transmitted waveform, robust to multipath channels. The designed non-coherent UWB transceiver architecture has an advantage of the simple realization since any mixer, high-speed correlator, and very high-sampling A/D converter are not necessary at the cost of performance degradation of about 3dB. Further, the designed non-coherent UWB transceiver is actually implemented with the wireless CANVAS prototyping testbed in short range indoor application environment such as a lecture room. The implemented prototype testbed is proven to offer the data rate of 9.6kbps and 115kbps on the conditions of Peer-to-Peer (P-to-P) in the indoor channel within the range of about 10m. At second, we analyze the bit error rate (BER) performance of this proposed system under the line-of-sight (LOS) residential channel environment. As a result, it is necessary to choose appropriate number of Window Bank(WB)s for better BER performance.

  8. Radio Astronomy

    NASA Technical Reports Server (NTRS)

    Wolken, P. R.; Shaffer, R. D.

    1983-01-01

    Deep Space Network (DSN) 26- and 64-meter antenna stations were utilized in support of Radio Astronomy Experiment Selection Panel experiments. Within a time span of 10 days, in May 1983 (267.75 hours total), nine RAES experiments were supported. Most of these experiments involved multifacility interferometry using Mark 3 data recording terminals and as many as six non-DSN observatories. Investigations of black holes, quasars, galaxies, and radio sources are discussed.

  9. Impact of fluorescence emission from gold atoms on surrounding biological tissue—implications for nanoparticle radio-enhancement

    NASA Astrophysics Data System (ADS)

    Byrne, H. L.; Gholami, Y.; Kuncic, Z.

    2017-04-01

    The addition of gold nanoparticles within target tissue (i.e. a tumour) to enhance the delivered radiation dose is a well studied radiotherapy treatment strategy, despite not yet having been translated into standard clinical practice. While several studies have used Monte Carlo simulations to investigate radiation dose enhancement by Auger electrons emitted from irradiated gold nanoparticles, none have yet considered the effects due to escaping fluorescence photons. Geant4 was used to simulate a water phantom containing 10 mg ml‑1 uniformly dispersed gold (1% by mass) at 5 cm depth. Incident monoenergetic photons with energies either side of the gold K-edge at 73 keV and 139.5 keV were chosen to give the same attenuation contrast against water, where water is used as a surrogate for biological tissue. For 73 keV incident photons, adding 1% gold into the water phantom enhances the energy deposited in the phantom by a factor of  ≈1.9 while 139.5 keV incident photons give a lower enhancement ratio of  ≈1.5. This difference in enhancement ratio, despite the equivalent attenuation ratios, can be attributed to energy carried from the target into the surrounding volume by fluorescence photons for the higher incident photon energy. The energy de-localisation is maximal just above the K-edge with 36% of the initial energy deposit in the phantom lost to escaping fluorescence photons. Conversely we find that the absorption of more photons by gold in the phantom reduces the number of scattered photons and hence energy deposited in the surrounding volume by up to 6% for incident photons below the K-edge. For incident photons above the K-edge this is somewhat offset by fluorescence. Our results give new insight into the previously unstudied centimetre scale energy deposition outside a target, which will be valuable for the future development of treatment plans using gold nanoparticles. From these results, we can conclude that gold nanoparticles

  10. Two Novel Space-Time Coding Techniques Designed for UWB MISO Systems Based on Wavelet Transform

    PubMed Central

    Zaki, Amira Ibrahim; El-Khamy, Said E.

    2016-01-01

    In this paper two novel space-time coding multi-input single-output (STC MISO) schemes, designed especially for Ultra-Wideband (UWB) systems, are introduced. The proposed schemes are referred to as wavelet space-time coding (WSTC) schemes. The WSTC schemes are based on two types of multiplexing, spatial and wavelet domain multiplexing. In WSTC schemes, four symbols are transmitted on the same UWB transmission pulse with the same bandwidth, symbol duration, and number of transmitting antennas of the conventional STC MISO scheme. The used mother wavelet (MW) is selected to be highly correlated with transmitted pulse shape and such that the multiplexed signal has almost the same spectral characteristics as those of the original UWB pulse. The two WSTC techniques increase the data rate to four times that of the conventional STC. The first WSTC scheme increases the data rate with a simple combination process. The second scheme achieves the increase in the data rate with a less complex receiver and better performance than the first scheme due to the spatial diversity introduced by the structure of its transmitter and receiver. The two schemes use Rake receivers to collect the energy in the dense multipath channel components. The simulation results show that the proposed WSTC schemes have better performance than the conventional scheme in addition to increasing the data rate to four times that of the conventional STC scheme. PMID:27959939

  11. A novel through-wall respiration detection algorithm using UWB radar.

    PubMed

    Li, Xin; Qiao, Dengyu; Li, Ye; Dai, Huhe

    2013-01-01

    Through-wall respiration detection using Ultra-wideband (UWB) impulse radar can be applied to the post-disaster rescue, e.g., searching living persons trapped in ruined buildings after an earthquake. Since strong interference signals always exist in the real-life scenarios, such as static clutter, noise, etc., while the respiratory signal is very weak, the signal to noise and clutter ratio (SNCR) is quite low. Therefore, through-wall respiration detection using UWB impulse radar under low SNCR is a challenging work in the research field of searching survivors after disaster. In this paper, an improved UWB respiratory signal model is built up based on an even power of cosine function for the first time. This model is used to reveal the harmonic structure of respiratory signal, based on which a novel high-performance respiration detection algorithm is proposed. This novel algorithm is assessed by experimental verification and simulation and shows about a 1.5dB improvement of SNR and SNCR.

  12. Simultaneous multi-channel CMW-band and MMW-band UWB monocycle pulse generation using FWM effect in a highly nonlinear photonic crystal fiber.

    PubMed

    Zhang, Fangzheng; Wu, Jian; Fu, Songnian; Xu, Kun; Li, Yan; Hong, Xiaobin; Shum, Ping; Lin, Jintong

    2010-07-19

    We propose and experimentally demonstrate a scheme to simultaneously realize multi-channel centimeter wave (CMW) band and millimeter wave (MMW) band ultra-wideband (UWB) monocycle pulse generation using four wave mixing (FWM) effect in a highly nonlinear photonic crystal fiber (HNL-PCF). Two lightwaves carrying polarity-reversed optical Gaussian pulses with appropriate time delay and another lightwave carrying a 20 GHz clock signal are launched into the HNL-PCF together. By filtering out the FWM idlers, two CMW-band UWB monocycle signals and two MMW-band UWB monocycle signals at 20 GHz are obtained simultaneously. Experimental measurements of the generated UWB monocycle pulses at individual wavelength, which comply with the FCC regulations, verify the feasibility and flexibility of proposed scheme for use in practical UWB communication systems.

  13. Enhancement of Compound Selectivity Using a Radio Frequency Ion-Funnel Proton Transfer Reaction Mass Spectrometer: Improved Specificity for Explosive Compounds.

    PubMed

    González-Méndez, Ramón; Watts, Peter; Olivenza-León, David; Reich, D Fraser; Mullock, Stephen J; Corlett, Clive A; Cairns, Stuart; Hickey, Peter; Brookes, Matthew; Mayhew, Chris A

    2016-11-01

    A key issue with any analytical system based on mass spectrometry with no initial separation of compounds is to have a high level of confidence in chemical assignment. This is particularly true for areas of security, such as airports, and recent terrorist attacks have highlighted the need for reliable analytical instrumentation. Proton transfer reaction mass spectrometry is a useful technology for these purposes because the chances of false positives are small owing to the use of a mass spectrometric analysis. However, the detection of an ion at a given m/z for an explosive does not guarantee that that explosive is present. There is still some ambiguity associated with any chemical assignment owing to the presence of isobaric compounds and, depending on mass resolution, ions with the same nominal m/z. In this article we describe how for the first time the use of a radio frequency ion-funnel (RFIF) in the reaction region (drift tube) of a proton transfer reaction-time-of-flight-mass spectrometer (PTR-ToF-MS) can be used to enhance specificity by manipulating the ion-molecule chemistry through collisional induced processes. Results for trinitrotoluene, dinitrotoluenes, and nitrotoluenes are presented to demonstrate the advantages of this new RFIF-PTR-ToF-MS for analytical chemical purposes.

  14. Radio astronomy

    NASA Technical Reports Server (NTRS)

    Kellermann, Kenneth I.; Heeschen, David; Backer, Donald C.; Cohen, Marshall H.; Davis, Michael; Depater, Imke; Deyoung, David; Dulk, George A.; Fisher, J. R.; Goss, W. Miller

    1991-01-01

    The following subject areas are covered: (1) scientific opportunities (millimeter and sub-millimeter wavelength astronomy; meter to hectometer astronomy; the Sun, stars, pulsars, interstellar masers, and extrasolar planets; the planets, asteroids, and comets; radio galaxies, quasars, and cosmology; and challenges for radio astronomy in the 1990's); (2) recommendations for new facilities (the millimeter arrays, medium scale instruments, and small-scale projects); (3) continuing activities and maintenance, upgrading of telescopes and instrumentation; (4) long range programs and technology development; and (5) social, political, and organizational considerations.

  15. Model of human breathing reflected signal received by PN-UWB radar.

    PubMed

    Mabrouk, Mohamed; Rajan, Sreeraman; Bolic, Miodrag; Batkin, Izmail; Dajani, Hilmi R; Groza, Voicu Z

    2014-01-01

    Human detection is an integral component of civilian and military rescue operations, military surveillance and combat operations. Human detection can be achieved through monitoring of vital signs. In this article, a mathematical model of human breathing reflected signal received in PN-UWB radar is proposed. Unlike earlier published works, both chest and abdomen movements are considered for modeling the radar return signal along with the contributions of fundamental breathing frequency and its harmonics. Analyses of recorded reflected signals from three subjects in different postures and at different ranges from the radar indicate that ratios of the amplitudes of the harmonics contain information about posture and posture change.

  16. SITE TECHNOLOGY CAPSULE: IITRI RADIO FREQUENCY HEATING TECHNOLOGY

    EPA Science Inventory

    Radio frequency heating (RFH) technologies use electromagnetic energy in the radio frequency (RF) band to heat soil in situ, thereby potentially enhancing the performance of standard soil vapor extraction (SVE) technologies. Contaminants are removed from in situ soils and transfe...

  17. The Radio JOVE Project - Shoestring Radio Astronomy

    NASA Technical Reports Server (NTRS)

    Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.

    2010-01-01

    Radio JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning radio astronomy. They can do this through building a radio telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (Radio Skypipe) and other reference materials

  18. Customization of UWB 3D-RTLS Based on the New Uncertainty Model of the AoA Ranging Technique.

    PubMed

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J

    2017-01-25

    The increased potential and effectiveness of Real-time Locating Systems (RTLSs) substantially influence their application spectrum. They are widely used, inter alia, in the industrial sector, healthcare, home care, and in logistic and security applications. The research aims to develop an analytical method to customize UWB-based RTLS, in order to improve their localization performance in terms of accuracy and precision. The analytical uncertainty model of Angle of Arrival (AoA) localization in a 3D indoor space, which is the foundation of the customization concept, is established in a working environment. Additionally, a suitable angular-based 3D localization algorithm is introduced. The paper investigates the following issues: the influence of the proposed correction vector on the localization accuracy; the impact of the system's configuration and LS's relative deployment on the localization precision distribution map. The advantages of the method are verified by comparing them with a reference commercial RTLS localization engine. The results of simulations and physical experiments prove the value of the proposed customization method. The research confirms that the analytical uncertainty model is the valid representation of RTLS' localization uncertainty in terms of accuracy and precision and can be useful for its performance improvement. The research shows, that the Angle of Arrival localization in a 3D indoor space applying the simple angular-based localization algorithm and correction vector improves of localization accuracy and precision in a way that the system challenges the reference hardware advanced localization engine. Moreover, the research guides the deployment of location sensors to enhance the localization precision.

  19. Customization of UWB 3D-RTLS Based on the New Uncertainty Model of the AoA Ranging Technique

    PubMed Central

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J.

    2017-01-01

    The increased potential and effectiveness of Real-time Locating Systems (RTLSs) substantially influence their application spectrum. They are widely used, inter alia, in the industrial sector, healthcare, home care, and in logistic and security applications. The research aims to develop an analytical method to customize UWB-based RTLS, in order to improve their localization performance in terms of accuracy and precision. The analytical uncertainty model of Angle of Arrival (AoA) localization in a 3D indoor space, which is the foundation of the customization concept, is established in a working environment. Additionally, a suitable angular-based 3D localization algorithm is introduced. The paper investigates the following issues: the influence of the proposed correction vector on the localization accuracy; the impact of the system’s configuration and LS’s relative deployment on the localization precision distribution map. The advantages of the method are verified by comparing them with a reference commercial RTLS localization engine. The results of simulations and physical experiments prove the value of the proposed customization method. The research confirms that the analytical uncertainty model is the valid representation of RTLS’ localization uncertainty in terms of accuracy and precision and can be useful for its performance improvement. The research shows, that the Angle of Arrival localization in a 3D indoor space applying the simple angular-based localization algorithm and correction vector improves of localization accuracy and precision in a way that the system challenges the reference hardware advanced localization engine. Moreover, the research guides the deployment of location sensors to enhance the localization precision. PMID:28125056

  20. Space Telecommunications Radio System STRS Cognitive Radio

    NASA Technical Reports Server (NTRS)

    Briones, Janette C.; Handler, Louis M.

    2013-01-01

    Radios today are evolving from awareness toward cognition. A software defined radio (SDR) provides the most capability for integrating autonomic decision making ability and allows the incremental evolution toward a cognitive radio. This cognitive radio technology will impact NASA space communications in areas such as spectrum utilization, interoperability, network operations, and radio resource management over a wide range of operating conditions. NASAs cognitive radio will build upon the infrastructure being developed by Space Telecommunication Radio System (STRS) SDR technology. This paper explores the feasibility of inserting cognitive capabilities in the NASA STRS architecture and the interfaces between the cognitive engine and the STRS radio. The STRS architecture defines methods that can inform the cognitive engine about the radio environment so that the cognitive engine can learn autonomously from experience, and take appropriate actions to adapt the radio operating characteristics and optimize performance.

  1. Investigation of broadband digital predistortion for broadband radio over fiber transmission systems

    NASA Astrophysics Data System (ADS)

    Zhang, Xiupu; Liu, Taijun; Shen, Dongya

    2016-12-01

    In future broadband cloud radio access networks (C-RAN), front-haul transmission systems play a significant role in performance and cost of C-RAN. Broadband and high linearity radio over fiber (RoF) transmission systems are considered a promising solution for the front-haul. Digital linearization is one possible solution for RoF front-haul. In this paper, we investigate RF domain digital predistortion (DPD) linearization for broadband RoF front-haul. The implemented DPD is first investigated in 2.4 GHz WiFi over fiber transmission systems at 36 Mb/s, and more than 8-dB and 5.6-dB improvements of error vector magnitude (EVM) are achieved in back to back (BTB) and after 10 km single mode fiber (SMF) transmission. Further, both WiFi and ultra wide band (UWB) wireless signals are transmitted together, in which the DPD has linearization bandwidth of 2.4 GHz. It is shown that the implemented DPD leads to EVM improvements of 4.5-dB (BTB) and 3.1-dB (10 km SMF) for the WiFi signal, and 4.6-dB (BTB) and 4-dB (10 km SMF) for the broadband UWB signal.

  2. Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems

    NASA Astrophysics Data System (ADS)

    Jiangwei, Yin; Ning, Li; Renliang, Zheng; Wei, Li; Junyan, Ren

    2009-05-01

    This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 μm RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 × 0.28 mm2. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

  3. Subbanding of temporal and spatial UWB SAR imagery of buried mines

    NASA Astrophysics Data System (ADS)

    Wong, David C.; Carin, Lawrence

    1998-09-01

    A numerical algorithm has been developed for the modeling of ultra-wideband (UWB) plane-wave scattering from a class of buried mines. In particular, the model assumes that a mine can be simulated as a body of revolution (BOR). The numerical results indicate that there are particular frequency subbands in which a given target is excited most strongly, with the subband depending strongly on the target type. Moreover, these optimal subbands are also dependent on the depression angle; therefore, the synthetic aperture radar (SAR) aperture must be limited (spatial-spectrum subbanding) so that the desired depression angle is achieved over the aperture used for imaging. These results indicate that the scattered response from particular buried mines can be highlighted by proper processing of the temporal and spatial spectrum. So motivated, we have applied subbanding to data measured by the Army Research Laboratory (ARL) UWB SAR, which collects fully polarimetric data over the 50 - 1200 MHz bandwidth. The measured data, when processed appropriately corroborate the theoretical expectations of where example anti-personnel and anti-tank mines scatter optimally. In particular, we consider the Valmara anti-personnel mine and the M20 anti-tank mine, using data collected at Yuma Proving Grounds. After validating the theory, we present frequency subbanding that will highlight one mine over another, a technique of potential application to the discrimination of targets from clutter.

  4. Design of UWB Monopole Antenna with Dual Notched Bands Using One Modified Electromagnetic-Bandgap Structure

    PubMed Central

    Xu, Ziqiang

    2013-01-01

    A modified electromagnetic-bandgap (M-EBG) structure and its application to planar monopole ultra-wideband (UWB) antenna are presented. The proposed M-EBG which comprises two strip patch and an edge-located via can perform dual notched bands. By properly designing and placing strip patch near the feedline, the proposed M-EBG not only possesses a simple structure and compact size but also exhibits good band rejection. Moreover, it is easy to tune the dual notched bands by altering the dimensions of the M-EBG. A demonstration antenna with dual band-notched characteristics is designed and fabricated to validate the proposed method. The results show that the proposed antenna can satisfy the requirements of VSWR < 2 over UWB 3.1–10.6 GHz, except for the rejected bands of the world interoperability for microwave access (WiMAX) and the wireless local area network (WLAN) at 3.5 GHz and 5.5 GHz, respectively. PMID:24170984

  5. Influence of the organism interface on the breast cancer detection by UWB

    NASA Astrophysics Data System (ADS)

    Xiao, Xia; Kikkawa, Takamaro

    2008-11-01

    Ultra-wide band (UWB) imaging technique is very attractive for the early breast cancer detection based on the obvious contrast in the electrical properties of malignant tumor to the normal fatty breast tissue. The tumor can be detected by analyzing the reflecting and scattering behavior of the UWB microwaves propagating in the breast. In this study, the influence of the organism interfaces is investigated from different cases of breast configuration involving different gland shapes as well as the tumor locations. Results show that the gland structure and tumor status have large influences on the reconstructed images generated from the detected signals due to the interface varieties. The tumor information in the proposed configurations can be obtained by series signal processing including eliminating the early time response of the detected signals caused by the direct wave and the reflection from the interface between the skin and the breast fat, and compensating the path loss of the propagating signal due to the radial spreading and the attenuation in the lossy breast. The location and the number of emitters and detectors affect the quality of the reconstructed image.

  6. A high linearity dual-band mixer for IMT-A and UWB systems

    NASA Astrophysics Data System (ADS)

    Xusheng, Tang; Xiaoyu, Wang; Jiang, Yang; Xin, Tang; Fengyi, Huang

    2014-11-01

    The design and analysis of a reconfigurable dual-band down-conversion mixer for IMT-advanced (3.4-3.6 GHz) and UWB (4.2-4.8 GHz) applications are presented. Based on a folded double-balanced Gilbert cell, which is well known for its low voltage, simplicity and well balanced performance, the mixer adopts a capacitive cross-coupling technique for input matching and performance improvement. Switched capacitors and resistors are added to shift the working bands. Fabricated in a TSMC 0.13 μm process, the test results show flat conversion gains from 9.6 to 10.3 dB on the IMT-A band and from 9.7 to 10.4 dB on the UWB band, with a noise figure of about 15 dB on both bands. The input third-order intercept points (IIP3) are about 7.3 dBm on both of the frequency bands. The whole chip consumes 11 mW under 1.2 V supply and the total area of the layout is 0.76 × 0.65 mm2.

  7. MB-OFDM-UWB Based Wireless Multimedia Sensor Networks for Underground Coalmine: A Survey

    PubMed Central

    Han, Ruisong; Yang, Wei; You, Kaiming

    2016-01-01

    Safety production of coalmines is a task of top priority which plays an important role in guaranteeing, supporting and promoting the continuous development of the coal industry. Since traditional wireless sensor networks (WSNs) cannot fully meet the requirements of comprehensive environment monitoring of underground coalmines, wireless multimedia sensor networks (WMSNs), enabling the retrieval of multimedia information, are introduced to realize fine-grained and precise environment surveillance. In this paper, a framework for designing underground coalmine WMSNs based on Multi-Band Orthogonal Frequency-Division Multiplexing Ultra-wide Band (MB-OFDM-UWB) is presented. The selection of MB-OFDM-UWB wireless transmission solution is based on the characteristics of underground coalmines. Network structure and design challenges are analyzed first, which is the foundation for further discussion. Then, key supporting technologies and open research areas in different layers are surveyed, and we provide a detailed literature review of the state of the art strategies, algorithms and general solutions in these issues. Finally, other research issues like localization, information processing, and network management are discussed. PMID:27999258

  8. Experimental Results of Site Calibration and Sensitivity Measurements in OTR for UWB Systems

    NASA Astrophysics Data System (ADS)

    Viswanadham, Chandana; Rao, P. Mallikrajuna

    2016-08-01

    System calibration and parameter accuracy measurement of electronic support measures (ESM) systems is a major activity, carried out by electronic warfare (EW) engineers. These activities are very critical and needs good understanding in the field of microwaves, antennas, wave propagation, digital and communication domains. EW systems are broad band, built with state-of-the art electronic hardware, installed on different varieties of military platforms to guard country's security from time to time. EW systems operate in wide frequency ranges, typically in the order of thousands of MHz, hence these are ultra wide band (UWB) systems. Few calibration activities are carried within the system and in the test sites, to meet the accuracies of final specifications. After calibration, parameters are measured for their accuracies either in feed mode by injecting the RF signals into the front end or in radiation mode by transmitting the RF signals on to system antenna. To carry out these activities in radiation mode, a calibrated open test range (OTR) is necessary in the frequency band of interest. Thus site calibration of OTR is necessary to be carried out before taking up system calibration and parameter measurements. This paper presents the experimental results of OTR site calibration and sensitivity measurements of UWB systems in radiation mode.

  9. UWB micro-doppler radar for human gait analysis using joint range-time-frequency representation

    NASA Astrophysics Data System (ADS)

    Wang, Yazhou; Fathy, Aly E.

    2013-05-01

    In this paper, we present a novel, standalone ultra wideband (UWB) micro-Doppler radar sensor that goes beyond simple range or micro-Doppler detection to combined range-time-Doppler frequency analysis. Moreover, it can monitor more than one human object in both line-of-sight (LOS) and through wall scenarios, thus have full human objects tracking capabilities. The unique radar design is based on narrow pulse transceiver, high speed data acquisition module, and wideband antenna array. For advanced radar post-data processing, joint range-time-frequency representation has been performed. Characteristics of human walking activity have been analyzed using the radar sensor by precisely tracking the radar object and acquiring range-time-Doppler information simultaneously. The UWB micro-Doppler radar prototype is capable of detecting Doppler frequency range from -180 Hz to +180 Hz, which allows a maximum target velocity of 9 m/s. The developed radar sensor can also be extended for many other applications, such as respiration and heartbeat detection of trapped survivors under building debris.

  10. Design of UWB monopole antenna with dual notched bands using one modified electromagnetic-bandgap structure.

    PubMed

    Liu, Hao; Xu, Ziqiang

    2013-01-01

    A modified electromagnetic-bandgap (M-EBG) structure and its application to planar monopole ultra-wideband (UWB) antenna are presented. The proposed M-EBG which comprises two strip patch and an edge-located via can perform dual notched bands. By properly designing and placing strip patch near the feedline, the proposed M-EBG not only possesses a simple structure and compact size but also exhibits good band rejection. Moreover, it is easy to tune the dual notched bands by altering the dimensions of the M-EBG. A demonstration antenna with dual band-notched characteristics is designed and fabricated to validate the proposed method. The results show that the proposed antenna can satisfy the requirements of VSWR < 2 over UWB 3.1-10.6 GHz, except for the rejected bands of the world interoperability for microwave access (WiMAX) and the wireless local area network (WLAN) at 3.5 GHz and 5.5 GHz, respectively.

  11. MB-OFDM-UWB Based Wireless Multimedia Sensor Networks for Underground Coalmine: A Survey.

    PubMed

    Han, Ruisong; Yang, Wei; You, Kaiming

    2016-12-16

    Safety production of coalmines is a task of top priority which plays an important role in guaranteeing, supporting and promoting the continuous development of the coal industry. Since traditional wireless sensor networks (WSNs) cannot fully meet the requirements of comprehensive environment monitoring of underground coalmines, wireless multimedia sensor networks (WMSNs), enabling the retrieval of multimedia information, are introduced to realize fine-grained and precise environment surveillance. In this paper, a framework for designing underground coalmine WMSNs based on Multi-Band Orthogonal Frequency-Division Multiplexing Ultra-wide Band (MB-OFDM-UWB) is presented. The selection of MB-OFDM-UWB wireless transmission solution is based on the characteristics of underground coalmines. Network structure and design challenges are analyzed first, which is the foundation for further discussion. Then, key supporting technologies and open research areas in different layers are surveyed, and we provide a detailed literature review of the state of the art strategies, algorithms and general solutions in these issues. Finally, other research issues like localization, information processing, and network management are discussed.

  12. RADIO ALTIMETERS

    DOEpatents

    Bogle, R.W.

    1960-11-22

    A radio ranging device is described which utilizes a superregenerative oscillator having alternate sending and receiving phases with an intervening ranging interval between said phases, means for varying said ranging interval, means responsive to an on-range noise reduction condition for stopping said means for varying the ranging interval and indicating means coupled to the ranging interval varying means and calibrated in accordance with one-half the product of the ranging interval times the velocity of light whereby the range is indicated.

  13. New VLA Observations for the HH 1-2 Region: Evidence for Density Enhancements Moving Along the Axis of the VLA 1 Radio Jet

    NASA Technical Reports Server (NTRS)

    Noriega-Crespo, A.; Rodriguez, L.; Delgado, V.; Gomez, Y.; Reipurth, B.; Torrelles, J.; Raga, A.; Canto, J.

    1999-01-01

    Using the Very Large Array, we have carried out new, sensitive radio continuum observations at 6 and 3.6 cm of the HH 1-2 region. The comparison between the 6 cm maps made from data taken in 1986.2 and 1992.9 indicates that VLA 1, the exciting source of the HH 1-2 flow, has suffered a morphological change that is attributed to the motion of a symmetric pair of knots along the axis of the radio jet.

  14. Radio Galaxy Zoo: host galaxies and radio morphologies derived from visual inspection

    NASA Astrophysics Data System (ADS)

    Banfield, J. K.; Wong, O. I.; Willett, K. W.; Norris, R. P.; Rudnick, L.; Shabala, S. S.; Simmons, B. D.; Snyder, C.; Garon, A.; Seymour, N.; Middelberg, E.; Andernach, H.; Lintott, C. J.; Jacob, K.; Kapińska, A. D.; Mao, M. Y.; Masters, K. L.; Jarvis, M. J.; Schawinski, K.; Paget, E.; Simpson, R.; Klöckner, H.-R.; Bamford, S.; Burchell, T.; Chow, K. E.; Cotter, G.; Fortson, L.; Heywood, I.; Jones, T. W.; Kaviraj, S.; López-Sánchez, Á. R.; Maksym, W. P.; Polsterer, K.; Borden, K.; Hollow, R. P.; Whyte, L.

    2015-11-01

    We present results from the first 12 months of operation of Radio Galaxy Zoo, which upon completion will enable visual inspection of over 170 000 radio sources to determine the host galaxy of the radio emission and the radio morphology. Radio Galaxy Zoo uses 1.4 GHz radio images from both the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) and the Australia Telescope Large Area Survey (ATLAS) in combination with mid-infrared images at 3.4 μm from the Wide-field Infrared Survey Explorer (WISE) and at 3.6 μm from the Spitzer Space Telescope. We present the early analysis of the WISE mid-infrared colours of the host galaxies. For images in which there is >75 per cent consensus among the Radio Galaxy Zoo cross-identifications, the project participants are as effective as the science experts at identifying the host galaxies. The majority of the identified host galaxies reside in the mid-infrared colour space dominated by elliptical galaxies, quasi-stellar objects and luminous infrared radio galaxies. We also find a distinct population of Radio Galaxy Zoo host galaxies residing in a redder mid-infrared colour space consisting of star-forming galaxies and/or dust-enhanced non-star-forming galaxies consistent with a scenario of merger-driven active galactic nuclei (AGN) formation. The completion of the full Radio Galaxy Zoo project will measure the relative populations of these hosts as a function of radio morphology and power while providing an avenue for the identification of rare and extreme radio structures. Currently, we are investigating candidates for radio galaxies with extreme morphologies, such as giant radio galaxies, late-type host galaxies with extended radio emission and hybrid morphology radio sources.

  15. Radio Jove: Jupiter Radio Astronomy for Citizens

    NASA Astrophysics Data System (ADS)

    Higgins, Charles; Thieman, J. R.; Flagg, R.; Reyes, F. J.; Sky, J.; Greenman, W.; Brown, J.; Typinski, D.; Ashcraft, T.; Mount, A.

    2014-01-01

    Radio JOVE is a hands-on educational activity that brings the radio sounds of the Sun, Jupiter, the Milky Way Galaxy, and terrestrial radio noise to students, teachers, and the general public. Participants may build a simple radio telescope kit, make scientific observations, and interact with professional radio observatories in real-time over the Internet. Our website (http://radiojove.gsfc.nasa.gov) includes science information, construction manuals, observing guides, and education resources for teachers and students. Radio Jove is continually expanding its participants with over 1800 kits sold to more than 70 countries worldwide. Recently some of our most dedicated observers have upgraded their Radio Jove antennas to semi-professional observatories. We have spectrographs and wide band antennas, some with 8 MHz bandwidth and some with dual polarization capabilities. In an effort to add to the science literature, these observers are coordinating their efforts to pursue some basic questions about Jupiter’s radio emissions (radio source locations, spectral structure, long term changes, etc.). We can compare signal and ionosphere variations using the many Radio Jove observers at different locations. Observers are also working with members of the Long Wavelength Array Station 1 (LWA1) radio telescope to coordinate observations of Jupiter; Radio Jove is planning to make coordinated observations while the Juno Mission is active beginning in 2015. The Radio Jove program is overviewed, its hardware and software are highlighted, recent sample observations are shown, and we demonstrate that we are capable of real citizen science.

  16. Experimental study of coexistence of multi-band OFDM-UWB and OFDM-baseband signals in long-reach PONs using directly modulated lasers.

    PubMed

    Morgado, José A P; Fonseca, Daniel; Cartaxo, Adolfo V T

    2011-11-07

    Transmission of coexisting Orthogonal Frequency Division Multiplexing (OFDM)-baseband (BB) and multi-band OFDM-ultra-wideband (UWB) signals along long-reach passive optical networks using directly modulated lasers (DML) is experimentally demonstrated.When optimized modulation indexes are used, bit error ratios not exceeding 5 × 10⁻⁴ can be achieved by all (OFDM-BB and three OFDM-UWB sub-bands) signals for a reach of 100 km of standard single-mode fiber (SSMF) and optical signal-to-noise ratios not lower than 25dB@0.1 nm. It is experimentally shown that, for the SSMF reach of 100km, the optimized performance of coexisting OFDM-BB and OFDM-UWB signals is mainly imposed by the combination of two effects: the SSMF dispersion-induced nonlinear distortion of the OFDM-UWB signals caused by the OFDM-BB and OFDM-UWB signals, and the further degradation of the OFDM-UWB signals with higher frequency, due to the reduced DML bandwidth.

  17. Learning radio astronomy by doing radio astronomy

    NASA Astrophysics Data System (ADS)

    Vaquerizo Gallego, J. A.

    2011-11-01

    PARTNeR (Proyecto Académico con el Radio Telescopio de NASA en Robledo, Academic Project with the NASA Radio Telescope at Robledo) is an educational program that allows high school and undergraduate students to control a 34 meter radio telescope and conduct radio astronomical observations via the internet. High-school teachers who join the project take a course to learn about the science of radio astronomy and how to use the antenna as an educational resource. Also, teachers are provided with learning activities they can do with their students and focused on the classroom implementation of the project within an interdisciplinary framework. PARTNeR provides students with firsthand experience in radio astronomy science. Thus, remote radio astronomical observations allow students to learn with a first rate scientific equipment the basics of radio astronomy research, aiming to arouse scientific careers and positive attitudes toward science. In this contribution we show the current observational programs and some recent results.

  18. A compact 5.5 GHz band-rejected UWB antenna using complementary split ring resonators.

    PubMed

    Islam, M M; Faruque, M R I; Islam, M T

    2014-01-01

    A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm(2), and VSWR < 2, observing band elimination of 5.5 GHz WLAN band.

  19. A magnetometer-free indoor human localization based on loosely coupled IMU/UWB fusion.

    PubMed

    Zihajehzadeh, Shaghayegh; Yoon, Paul K; Park, Edward J

    2015-01-01

    The magnetic distortions in indoor environment affects the accuracy of yaw angle estimation using magnetometer. Thus, the accuracy of indoor localization based on inertial-magnetic sensors will be affected as well. To address this issue, this paper proposes a magnetometer-free solution for indoor human localization and yaw angle estimation. The proposed algorithm fuses a wearable inertial sensor consisting of MEMS-based accelerometer and gyroscope with a portable ultra-wideband (UWB) localization system in a cascaded two-step filter consisting of a tilt Kalman filter and a localization Kalman filter. By benchmarking against an optical motion capture system, the experimental results show that the proposed algorithm can accurately track position and velocity as well as the yaw angle without using magnetometer.

  20. A Compact 5.5 GHz Band-Rejected UWB Antenna Using Complementary Split Ring Resonators

    PubMed Central

    Islam, M. M.; Faruque, M. R. I.; Islam, M. T.

    2014-01-01

    A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm2, and VSWR < 2, observing band elimination of 5.5 GHz WLAN band. PMID:24971379

  1. Design of Compact Flower Shape Dual Notched-Band Monopole Antenna for Extended UWB Wireless Applications

    NASA Astrophysics Data System (ADS)

    Sharma, Manish; Awasthi, Y. K.; Singh, Himanshu; Kumar, Raj; Kumari, Sarita

    2016-11-01

    In this letter, a compact monopole antenna for ultra wideband (UWB) applications is proposed with small size of 18×20=360 mm2. Antenna consist of a flower shape radiating patch with a pair of C-shaped slots which offer two notch bands for WiMAX (3.04-3.68 GHz) & WLAN (4.73-5.76 GHz) and two rectangular shaped slots in the ground plane which provides a wide measured usable fractional extended bandwidth of 163 % (2.83-14.0 GHz) with improved VSWR. Moreover, it is also convenient for other wireless application as close range radar, 8-12 GHz in X-band. Measured radiation patterns exhibits nearly omnidirectional in H-plane and dipole like pattern in E-plane across the bandwidth and furthermore exhibits good time domain performance.

  2. High speed Radix-4 soft-decision Viterbi decoder for MB-OFDM UWB system

    NASA Astrophysics Data System (ADS)

    Liang, Guixuan; Portilla, Jorge; Riesgo, Teresa

    2013-05-01

    In this paper, a 64 state soft decision Viterbi Decoder (VD) system by using a high speed radix-4 Add Compare Select (ACS) architecture is presented. The proposed VD system can support different data rate (from 53.5 Mbps to 480 Mbps) for Multiband Orthogonal Frequency-division Multiplexing (MB-OFDM) Ultra-Wideband (UWB) system when implemented onto the FPGA board. The proposed VD employs efficient two steps Radix 4 architecture, which is responsible of calculating two steps of 64 state Radix 4 Branch Metrics (BM) within one clock cycle. The branch metrics are calculated using a uniform distance measurement algorithm, which equals to the symbol itself when compared to logic-0 and equal to its one's complement when compared to logic-1. By employing the modified Modulo Normalization algorithm, it is possible to use only a 10- bit memory block to restore each of the 64 state metrics, with the advantage of avoiding errors caused by overflow during the updating process for state metrics, and simplifying the comparator circuit of the ACS unit. The Two Pointer Even Algorithm, which is considered to be very simple and more hardware-efficient than the register exchange algorithm, is used for tracing back the survivor sequence and output the decoded data stream. 3-bit soft decision input sequences are used for gathering the experimental results. The sampling frequency of the MBOFDM UWB system is 528 MHz, by using the proposed two steps Radix 4 VD architecture we can process 4 input signals in parallel within one clock cycle, therefore only 132 MHz operating frequency is needed for the proposed VD system. This will dramatically reduce the dynamic power consumption for hardware implementation. Final results of the implementation show that the proposed VD architecture can support a maximum working frequency of 152.5 MHz on Xilinx XUPV5-LX110T Evaluation Platform.

  3. The Radio Amateur's Handbook.

    ERIC Educational Resources Information Center

    Blakeslee, Douglas, Ed.

    The objectives of this basic reference work for the radio amateur are to present radio theory and practice in terms of application and to reflect both the fundamentals and the rapidly-advancing technology of radio communications so that the radio amateur will have a guide to what is practical, meaningful, proven, and useful. Twenty-three chapters…

  4. The Frequency Spectrum Radio.

    ERIC Educational Resources Information Center

    Howkins, John, Ed.

    1979-01-01

    This journal issue focuses on the frequency spectrum used in radio communication and on the World Administrative Radio Conference, sponsored by the International Telecommunication Union, held in Geneva, Switzerland, in the fall of 1979. Articles describe the World Administrative Radio Conference as the most important radio communication conference…

  5. Sensing through the wall imaging using the Army Research Lab ultra-wideband synchronous impulse reconstruction (UWB SIRE) radar

    NASA Astrophysics Data System (ADS)

    Nguyen, Lam; Ressler, Marc; Sichina, Jeffrey

    2008-04-01

    The U.S. Army Research Laboratory (ARL), as part of a mission and customer funded exploratory program, has developed a new low-frequency, ultra-wideband (UWB) synthetic aperture radar (SAR). The radar is capable of penetrating enclosed areas (buildings) and generating SAR imagery. This supports the U.S. Army's need for intelligence on the configuration, content, and human presence inside these enclosed areas. The radar system is mounted on a ground based vehicle traveling along the road and is configured with an array of antennas pointing toward the enclosed areas of interest. This paper will describe an experiment conducted recently at Aberdeen Proving Ground (APG), Maryland. In this paper we briefly describe the UWB SIRE radar and the test setup in the experiment. We will also describe the signal processing and the image techniques used to produce the SAR imagery. Finally, we will present SAR imagery of the building and its internal structure from different viewing directions.

  6. A 10.6mm3 Fully-Integrated, Wireless Sensor Node with 8GHz UWB Transmitter

    PubMed Central

    Kim, Hyeongseok; Kim, Gyouho; Lee, Yoonmyung; Foo, Zhiyoong; Sylvester, Dennis; Blaauw, David; Wentzloff, David

    2015-01-01

    This paper presents a complete, autonomous, wireless temperature sensor, fully encapsulated in a 10.6mm3 volume. The sensor includes solar energy harvesting with an integrated 2 μAh battery, optical receiver for programming, microcontroller and memory, 8GHz UWB transmitter, and miniaturized custom antennas with a wireless range of 7 meters. Full, stand-alone operation was demonstrated for the first time for a system of this size and functionality. PMID:26855848

  7. Integrable high order UWB pulse photonic generator based on cross phase modulation in a SOA-MZI.

    PubMed

    Moreno, Vanessa; Rius, Manuel; Mora, José; Muriel, Miguel A; Capmany, José

    2013-09-23

    We propose and experimentally demonstrate a potentially integrable optical scheme to generate high order UWB pulses. The technique is based on exploiting the cross phase modulation generated in an InGaAsP Mach-Zehnder interferometer containing integrated semiconductor optical amplifiers, and is also adaptable to different pulse modulation formats through an optical processing unit which allows to control of the amplitude, polarity and time delay of the generated taps.

  8. Compact self-grounded Bow-Tie antenna design for an UWB phased-array hyperthermia applicator.

    PubMed

    Takook, Pegah; Persson, Mikael; Gellermann, Johanna; Trefná, Hana Dobšíček

    2017-01-08

    Using UWB hyperthermia systems has the potential to improve the heat delivery to deep seated tumours. In this paper, we present a novel self-grounded Bow-Tie antenna design which is to serve as the basis element in a phased-array applicator. The UWB operation in the frequency range of 0.43-1 GHz is achieved by immersing the antenna in a water bolus. The radiation characteristics are improved by appropriate shaping the water bolus and by inclusion of dielectric layers on the top of the radiating arms of the antenna. In order to find the most appropriate design, we use a combination of performance indicators representing the most important attributes of the antenna. These are the UWB impedance matching, the transmission capability and the effective field size. The antenna was constructed and experimentally validated on muscle-like phantom. The measured reflection and transmission coefficients as well as radiation characteristics are in excellent agreement with the simulated results. MR image acquisitions with antenna located inside MR bore indicate a negligible distortion of the images by the antenna itself, which indicates MR compatibility.

  9. Through-the-wall localization of a moving target by two independent ultra wideband (UWB) radar systems.

    PubMed

    Kocur, Dušan; Svecová, Mária; Rovňáková, Jana

    2013-09-09

    In the case of through-the-wall localization of moving targets by ultra wideband (UWB) radars, there are applications in which handheld sensors equipped only with one transmitting and two receiving antennas are applied. Sometimes, the radar using such a small antenna array is not able to localize the target with the required accuracy. With a view to improve through-the-wall target localization, cooperative positioning based on a fusion of data retrieved from two independent radar systems can be used. In this paper, the novel method of the cooperative localization referred to as joining intersections of the ellipses is introduced. This method is based on a geometrical interpretation of target localization where the target position is estimated using a properly created cluster of the ellipse intersections representing potential positions of the target. The performance of the proposed method is compared with the direct calculation method and two alternative methods of cooperative localization using data obtained by measurements with the M-sequence UWB radars. The direct calculation method is applied for the target localization by particular radar systems. As alternative methods of cooperative localization, the arithmetic average of the target coordinates estimated by two single independent UWB radars and the Taylor series method is considered.

  10. Spotforming with an Array of Ultra-Wideband Radio Transmitters

    SciTech Connect

    Dowla, F; Spiridon, A

    2003-09-29

    Ultra-wideband (UWB) array signal processing has the distinct advantage in that it is possible to illuminate or focus on ''spots'' at distant points in space, as opposed to just illuminating or steering at certain directions for narrowband array processing. The term ''spotforming'' is used to emphasize the property that point-focusing techniques with UWB waveforms can be viewed as a generalization of the well-known narrowband beamforming techniques. Because methods in spotforming can lead to powerful applications for UWB systems, in this paper we derive, simulate and experimentally verify UWB spot size as a function of frequency, bandwidth and array aperture.

  11. Spotforming with an array of ultra-wideband radio transmitters

    SciTech Connect

    Dowla, F; Spiridon, A

    2004-02-05

    Ultra-wideband (UWB) array signal processing has the distinct advantage in that it is possible to illuminate or focus on ''spots'' at distant points in space, as opposed to just illuminating or steering at certain directions for narrowband array processing. The term ''spotforming'' is used to emphasize the property that point-focusing techniques with UWB waveforms can be viewed as a generalization of the well-known narrowband beamforming techniques. Because methods in spotforming can lead to powerful applications for UWB systems, in this paper we derive, simulate and experimentally verify UWB spot size as a function of frequency, bandwidth and array aperture.

  12. Radio frequency detection assembly and method for detecting radio frequencies

    SciTech Connect

    Cown, Steven H.; Derr, Kurt Warren

    2010-03-16

    A radio frequency detection assembly is described and which includes a radio frequency detector which detects a radio frequency emission produced by a radio frequency emitter from a given location which is remote relative to the radio frequency detector; a location assembly electrically coupled with the radio frequency detector and which is operable to estimate the location of the radio frequency emitter from the radio frequency emission which has been received; and a radio frequency transmitter electrically coupled with the radio frequency detector and the location assembly, and which transmits a radio frequency signal which reports the presence of the radio frequency emitter.

  13. Radio frequency coaxial feedthrough

    DOEpatents

    Owens, Thomas L.

    1989-01-17

    An improved radio frequency coaxial transmission line vacuum feed-through provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflections from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits voltage and power handling capabilities of a feedthrough.

  14. Resonance and Radio

    ERIC Educational Resources Information Center

    Starrett, Malin J.

    2008-01-01

    The science and technology of radio receives little attention in contemporary education. This article discusses ways to explore the basic operating principles of radio. (Contains 4 figures, 3 footnotes, and 2 notes.)

  15. Link Dependent Adaptive Radio Simulation

    DTIC Science & Technology

    2014-06-01

    14. ABSTRACT This paper shows the optimized Link Dependent Adaptive Radio (LDAR) using the variable QAM OFDM modulation size which adapts to channel...bit error rate (BER), Orthogonal Frequency Division Multiplexing ( OFDM ) 16. SECURITY CLASSIFICATION OF: Unclassified 17. LIMITATION OF ABSTRACT...using the variable QAM OFDM modulation size which adapts to channel conditions. The LDAR enhanced performance is illustrated by use of a flight path

  16. Commercial Radio as Communication.

    ERIC Educational Resources Information Center

    Rothenbuhler, Eric W.

    1996-01-01

    Compares the day-to-day work routines of commercial radio with the principles of a theoretical communication model. Illuminates peculiarities of the conduct of communication by commercial radio. Discusses the application of theoretical models to the evaluation of practicing institutions. Offers assessments of commercial radio deriving from…

  17. Extragalactic Radio Sources

    ERIC Educational Resources Information Center

    Kellerman, Kenneth I.

    1973-01-01

    Discusses new problems arising from the growing observational data through radio telescope arrays, involving the origin of radio sources, apparent superluminal velocities, conversion of radio sources to relativistic particles, and the nature of compact opaque and extended transparent sources. New physics may be needed to answer these cosmological…

  18. A multiuser detector based on artificial bee colony algorithm for DS-UWB systems.

    PubMed

    Yin, Zhendong; Liu, Xiaohui; Wu, Zhilu

    2013-01-01

    Artificial Bee Colony (ABC) algorithm is an optimization algorithm based on the intelligent behavior of honey bee swarm. The ABC algorithm was developed to solve optimizing numerical problems and revealed premising results in processing time and solution quality. In ABC, a colony of artificial bees search for rich artificial food sources; the optimizing numerical problems are converted to the problem of finding the best parameter which minimizes an objective function. Then, the artificial bees randomly discover a population of initial solutions and then iteratively improve them by employing the behavior: moving towards better solutions by means of a neighbor search mechanism while abandoning poor solutions. In this paper, an efficient multiuser detector based on a suboptimal code mapping multiuser detector and artificial bee colony algorithm (SCM-ABC-MUD) is proposed and implemented in direct-sequence ultra-wideband (DS-UWB) systems under the additive white Gaussian noise (AWGN) channel. The simulation results demonstrate that the BER and the near-far effect resistance performances of this proposed algorithm are quite close to those of the optimum multiuser detector (OMD) while its computational complexity is much lower than that of OMD. Furthermore, the BER performance of SCM-ABC-MUD is not sensitive to the number of active users and can obtain a large system capacity.

  19. SEMICONDUCTOR INTEGRATED CIRCUITS: A low-spurious fast-hopping MB-OFDM UWB synthesizer

    NASA Astrophysics Data System (ADS)

    Danfeng, Chen; Wei, Li; Ning, Li; Junyan, Ren

    2010-06-01

    A frequency synthesizer for the ultra-wide band (UWB) group #1 is proposed. The synthesizer uses a phase-locked loop (PLL) and single-sideband (SSB) mixers to generate the three center frequencies of the first band group by mixing 4224 MHz with ±264 MHz and 792 MHz, respectively. A novel multi-QSSB mixer is designed to combine the function of frequency selection and frequency conversion for low power and high linearity. The synthesizer is fabricated in Jazz 0.18-μm RF CMOS technology. The measured reference spur is as low as -69 dBc and the maximum spur is the LO leakage of -32 dBc. A low phase noise of -110 dBc/Hz @ 1 MHz offset and an integrated phase noise of 1.86° are achieved. The hopping time between different bands is less than 1.8 ns. The synthesizer consumes 30 mA from a 1.8 V supply.

  20. Time-lapse imaging of human heart motion with switched array UWB radar.

    PubMed

    Brovoll, Sverre; Berger, Tor; Paichard, Yoann; Aardal, Øyvind; Lande, Tor Sverre; Hamran, Svein-Erik

    2014-10-01

    Radar systems for detection of human heartbeats have mostly been single-channel systems with limited spatial resolution. In this paper, a radar system for ultra-wideband (UWB) imaging of the human heart is presented. To make the radar waves penetrate the human tissue the antenna is placed very close to the body. The antenna is an array with eight elements, and an antenna switch system connects the radar to the individual elements in sequence to form an image. Successive images are used to build up time-lapse movies of the beating heart. Measurements on a human test subject are presented and the heart motion is estimated at different locations inside the body. The movies show rhythmic motion consistent with the beating heart, and the location and shape of the reflections correspond well with the expected response form the heart wall. The spatial dependent heart motion is compared to ECG recordings, and it is confirmed that heartbeat modulations are seen in the radar data. This work shows that radar imaging of the human heart may provide valuable information on the mechanical movement of the heart.

  1. PCA-based artifact removal algorithm for stroke detection using UWB radar imaging.

    PubMed

    Ricci, Elisa; di Domenico, Simone; Cianca, Ernestina; Rossi, Tommaso; Diomedi, Marina

    2016-09-16

    Stroke patients should be dispatched at the highest level of care available in the shortest time. In this context, a transportable system in specialized ambulances, able to evaluate the presence of an acute brain lesion in a short time interval (i.e., few minutes), could shorten delay of treatment. UWB radar imaging is an emerging diagnostic branch that has great potential for the implementation of a transportable and low-cost device. Transportability, low cost and short response time pose challenges to the signal processing algorithms of the backscattered signals as they should guarantee good performance with a reasonably low number of antennas and low computational complexity, tightly related to the response time of the device. The paper shows that a PCA-based preprocessing algorithm can: (1) achieve good performance already with a computationally simple beamforming algorithm; (2) outperform state-of-the-art preprocessing algorithms; (3) enable a further improvement in the performance (and/or decrease in the number of antennas) by using a multistatic approach with just a modest increase in computational complexity. This is an important result toward the implementation of such a diagnostic device that could play an important role in emergency scenario.

  2. Flexible, Polarization-Diverse UWB Antennas for Implantable Neural Recording Systems.

    PubMed

    Bahrami, Hadi; Mirbozorgi, S Abdollah; Ameli, Reza; Rusch, Leslie A; Gosselin, Benoit

    2016-02-01

    Implanted antennas for implant-to-air data communications must be composed of material compatible with biological tissues. We design single and dual-polarization antennas for wireless ultra-wideband neural recording systems using an inhomogeneous multi-layer model of the human head. Antennas made from flexible materials are more easily adapted to implantation; we investigate both flexible and rigid materials and examine performance trade-offs. The proposed antennas are designed to operate in a frequency range of 2-11 GHz (having S11 below -10 dB) covering both the 2.45 GHz (ISM) band and the 3.1-10.6 GHz UWB band. Measurements confirm simulation results showing flexible antennas have little performance degradation due to bending effects (in terms of impedance matching). Our miniaturized flexible antennas are 12 mm×12 mm and 10 mm×9 mm for single- and dual-polarizations, respectively. Finally, a comparison is made of four implantable antennas covering the 2-11 GHz range: 1) rigid, single polarization, 2) rigid, dual polarization, 3) flexible, single polarization and 4) flexible, dual polarization. In all cases a rigid antenna is used outside the body, with an appropriate polarization. Several advantages were confirmed for dual polarization antennas: 1) smaller size, 2) lower sensitivity to angular misalignments, and 3) higher fidelity.

  3. Entropy-Based TOA Estimation and SVM-Based Ranging Error Mitigation in UWB Ranging Systems.

    PubMed

    Yin, Zhendong; Cui, Kai; Wu, Zhilu; Yin, Liang

    2015-05-21

    The major challenges for Ultra-wide Band (UWB) indoor ranging systems are the dense multipath and non-line-of-sight (NLOS) problems of the indoor environment. To precisely estimate the time of arrival (TOA) of the first path (FP) in such a poor environment, a novel approach of entropy-based TOA estimation and support vector machine (SVM) regression-based ranging error mitigation is proposed in this paper. The proposed method can estimate the TOA precisely by measuring the randomness of the received signals and mitigate the ranging error without the recognition of the channel conditions. The entropy is used to measure the randomness of the received signals and the FP can be determined by the decision of the sample which is followed by a great entropy decrease. The SVM regression is employed to perform the ranging-error mitigation by the modeling of the regressor between the characteristics of received signals and the ranging error. The presented numerical simulation results show that the proposed approach achieves significant performance improvements in the CM1 to CM4 channels of the IEEE 802.15.4a standard, as compared to conventional approaches.

  4. Application of power transformation and moments in time based UWB ranging

    NASA Astrophysics Data System (ADS)

    Liu, Wenyan; Huang, Xiaotao

    2016-04-01

    For ultra-wideband (UWB) ranging, TOA estimation with the energy detection (ED) receiver is to detect the energy sample that contains the first path (FP) signal in dense multipath. Threshold crossing (TC) is used frequently. However, it is difficult to determine the threshold. Some threshold setting methods are based on constant false alarm rate (CFAR) and the chi-squared distribution. However, the distribution is complicated. Moreover, it depends on the degree of freedom (DOF). If the DOF used is wrong, it will degrade the detection performance. The study bypasses the distribution. We first examine the distribution of the output of the ED receiver after power transformation. Based on the new characteristics of the transformed data and approximate distributions, we propose some practical TOA estimation methods. Similarly, the moments of the output of the ED receiver, such as the second or one-third order moments, are also analysed and used. The proposed methods are easy to implement and can achieve about the same ranging performance with methods based on the chi-squared distribution. We provide both theoretical and simulation results to prove their effectiveness.

  5. UWB Band-notched Adjustable Antenna Using Concentric Split-ring Slots Structure

    NASA Astrophysics Data System (ADS)

    Yin, Y.; Hong, J. S.

    2014-09-01

    In this paper, a kind of concentric split-ring slots structure is utilized to design a novel triple-band-notched UWB antenna. Firstly, a concentric split-ring slots structure that has a higher VSWR than that of a single slot at notch frequency is presented. What's more, the structure is very simple and feasible to obtain notched-band at different frequency by adjustment of the length of slot. Secondly, a triple-band-notched antenna, whose notched bands are at 3.52-3.81 GHz for WiMAX and 5.03-5.42 GHz and 5.73-56.17 GHz for WLAN, is designed by using this structure. At last, a compact size of 24 × 30 mm2 of the proposed antenna has been fabricated and measured and it is shown that the proposed antenna has a broadband matched impedance (3.05-14 GHz, VSWR < 2), relatively stable gain and good omnidirectional radiation patterns at low bands.

  6. Three-Dimensional Planetary Surface Tracking Based on a Simple Ultra-Wideband Impulse-Radio Infrastructure

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.; Ni, David; Ngo, Phong

    2010-01-01

    Several prototype ultra-wideband (UWB) impulse-radio (IR) tracking systems are currently under development at NASA Johnson Space Center (JSC). These systems are being studied for use in tracking of Lunar/Mars rovers and astronauts during early exploration missions when satellite navigation systems (such as GPS) are not available. To date, the systems that have been designed and tested are intended only for two-dimensional location and tracking, but these designs can all be extended to three-dimensional tracking with only minor modifications and increases in complexity. In this presentation, we will briefly review the design and performance of two of the current 2-D systems: one designed specifically for short-range, extremely high-precision tracking (approximately 1-2 cm resolution) and the other designed specifically for much longer range tracking with less stringent precision requirements (1-2 m resolution). We will then discuss a new multi-purpose system design based on a simple UWB-IR architecture that can be deployed easily on a planetary surface to support arbitrary three-dimensional localization and tracking applications. We will discuss utilization of this system as an infrastructure to provide both short-range and long-range tracking and analyze the localization performance of the system in several different configurations. We will give theoretical performance bounds for some canonical system configurations and compare these performance bounds with both numerical simulations of the system as well as actual experimental system performance evaluations.

  7. Radio wave propagation and acoustic sounding

    NASA Astrophysics Data System (ADS)

    Singal, S. P.

    Radio wave propagation of the decimetric and centimetric waves depends to a large extent on the boundary layer meteorological conditions which give rise to severe fadings, very often due to multipath propagation. Sodar is one of the inexpensive remote sensing techniques which can be employed to probe the boundary layer structure. In the paper a historical perspective has been given of the simultaneously conducted studies on radio waves and sodar at various places. The radio meteorological information needed for propagation studies has been clearly spelt out and conditions of a ray path especially in the presence of a ducting layer have been defined as giving rise to fading or signal enhancement conditions. Finally the potential of the sodar studies to obtain information about the boundary layer phenomena has been stressed, clearly spelling out the use of acoustic sounding in radio wave propagation studies.

  8. Parg deficiency confers radio-sensitization through enhanced cell death in mouse ES cells exposed to various forms of ionizing radiation.

    PubMed

    Shirai, Hidenori; Fujimori, Hiroaki; Gunji, Akemi; Maeda, Daisuke; Hirai, Takahisa; Poetsch, Anna R; Harada, Hiromi; Yoshida, Tomoko; Sasai, Keisuke; Okayasu, Ryuichi; Masutani, Mitsuko

    2013-05-24

    Poly(ADP-ribose) glycohydrolase (Parg) is the main enzyme involved in poly(ADP-ribose) degradation. Here, the effects of Parg deficiency on sensitivity to low and high linear-energy-transfer (LET) radiation were investigated in mouse embryonic stem (ES) cells. Mouse Parg(-/-) and poly(ADP-ribose) polymerase-1 deficient (Parp-1(-/-)) ES cells were used and responses to low and high LET radiation were assessed by clonogenic survival and biochemical and biological analysis methods. Parg(-/-) cells were more sensitive to γ-irradiation than Parp-1(-/-) cells. Transient accumulation of poly(ADP-ribose) was enhanced in Parg(-/-) cells. Augmented levels of phosphorylated H2AX (γ-H2AX) from early phase were observed in Parg(-/-) ES cells. The induction level of p53 phophorylation at ser18 was similar in wild-type and Parp-1(-/-) cells and apoptotic cell death process was mainly observed in the both genotypes. These results suggested that the enhanced sensitivity of Parg(-/-) ES cells to γ-irradiation involved defective repair of DNA double strand breaks. The effects of Parg and Parp-1 deficiency on the ES cell response to carbon-ion irradiation (LET13 and 70 keV/μm) and Fe-ion irradiation (200 keV/μm) were also examined. Parg(-/-) cells were more sensitive to LET 70 keV/μm carbon-ion irradiation than Parp-1(-/-) cells. Enhanced apoptotic cell death also accompanied augmented levels of γ-H2AX in a biphasic manner peaked at 1 and 24h. The induction level of p53 phophorylation at ser18 was not different between wild-type and Parg(-/-) cells. The augmented level of poly(ADP-ribose) accumulation was noted after carbon-ion irradiation compared to γ-irradiation even in the wild-type cells. An enhanced poly(ADP-ribose) accumulation was further observed in Parg(-/-) cells. Both Parg(-/-) cells and Parp-1(-/-) cells did not show sensitization to Fe-ion irradiation. Parg deficiency sensitizes mouse ES cells to a wide therapeutic range of LET radiation through the effects on

  9. Dominion Radio Astrophysical Observatory

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The Dominion Radio Astrophysical Observatory began operating in 1959, and joined the NATIONAL RESEARCH COUNCIL in 1970. It became part of the Herzberg Institute of Astrophysics in 1975. The site near Penticton, BC has a 26 m radio telescope, a seven-antenna synthesis telescope on a 600 m baseline and two telescopes dedicated to monitoring the solar radio flux at 10.7 cm. This part of the Institu...

  10. Radio determination satellite service

    NASA Astrophysics Data System (ADS)

    Briskman, Robert D.

    1990-07-01

    The capabilities and measured performance of a geosynchronous satellite-based service called the radio determination satellite service (RDSS), which operates at radio frequencies allocated by the International Telecommunications Union (ITU) and is licensed in the United States by the Federal Communications Commission (FCC), are discussed. Plans for both improvement in capability and expansion to nearly global coverage are described. Since RDSS can also provide radio navigation, some comparisons of this service with the Global Positioning System (GPS) are made.

  11. All-optical UWB generation and modulation using SOA-XPM effect and DWDM-based multi-channel frequency discrimination.

    PubMed

    Wang, Fei; Dong, Jianji; Xu, Enming; Zhang, Xinliang

    2010-11-22

    An all-optical UWB pulses generation and modulation scheme using cross phase modulation (XPM) effect of semiconductor optical amplifier (SOA) and DWDM-based multi-channel frequency discrimination is proposed and demonstrated, which has potential application in multiuser UWB-Over-Fiber communication systems. When a Gaussian pulse light and a wavelength-tunable CW probe light are together injected into the SOA, the probe light out from the SOA will have a temporal chirp due to SOA-XPM effect. When the chirped probe light is tuned to the slopes of single DWDM channel transmittance curve, the optical phase modulation to intensity modulation conversion is achieved at DWDM that serves as a multi-channel frequency discriminator, the inverted polarity Gaussian monocycle and doublet pulse is detected by a photodetector, respectively. If the probe lights are simultaneously aimed to different slopes of several DWDM channels, multi-channel or binary-phase-coded UWB signal generation can be acquired. Using proposed scheme, pulse amplitude modulation (PAM), pulse polarity modulation (PPM) and pulse shape modulation (PSM) to UWB pulses also can be conveniently realized.

  12. Parg deficiency confers radio-sensitization through enhanced cell death in mouse ES cells exposed to various forms of ionizing radiation

    SciTech Connect

    Shirai, Hidenori; Fujimori, Hiroaki; Gunji, Akemi; Maeda, Daisuke; Hirai, Takahisa; Poetsch, Anna R.; Harada, Hiromi; Yoshida, Tomoko; Sasai, Keisuke; Okayasu, Ryuichi; Masutani, Mitsuko

    2013-05-24

    Highlights: •Parg{sup −/−} ES cells were more sensitive to γ-irradiation than Parp-1{sup −/−} ES cells. •Parg{sup −/−} cells were more sensitive to carbon-ion irradiation than Parp-1{sup −/−} cells. •Parg{sup −/−} cells showed defects in DSB repair after carbon-ion irradiation. •PAR accumulation was enhanced after carbon-ion irradiation compared to γ-irradiation. -- Abstract: Poly(ADP-ribose) glycohydrolase (Parg) is the main enzyme involved in poly(ADP-ribose) degradation. Here, the effects of Parg deficiency on sensitivity to low and high linear-energy-transfer (LET) radiation were investigated in mouse embryonic stem (ES) cells. Mouse Parg{sup −/−} and poly(ADP-ribose) polymerase-1 deficient (Parp-1{sup −/−}) ES cells were used and responses to low and high LET radiation were assessed by clonogenic survival and biochemical and biological analysis methods. Parg{sup −/−} cells were more sensitive to γ-irradiation than Parp-1{sup −/−} cells. Transient accumulation of poly(ADP-ribose) was enhanced in Parg{sup −/−} cells. Augmented levels of phosphorylated H2AX (γ-H2AX) from early phase were observed in Parg{sup −/−} ES cells. The induction level of p53 phophorylation at ser18 was similar in wild-type and Parp-1{sup −/−} cells and apoptotic cell death process was mainly observed in the both genotypes. These results suggested that the enhanced sensitivity of Parg{sup −/−} ES cells to γ-irradiation involved defective repair of DNA double strand breaks. The effects of Parg and Parp-1 deficiency on the ES cell response to carbon-ion irradiation (LET13 and 70 keV/μm) and Fe-ion irradiation (200 keV/μm) were also examined. Parg{sup −/−} cells were more sensitive to LET 70 keV/μm carbon-ion irradiation than Parp-1{sup −/−} cells. Enhanced apoptotic cell death also accompanied augmented levels of γ-H2AX in a biphasic manner peaked at 1 and 24 h. The induction level of p53 phophorylation at ser18 was

  13. MRI-aided tissues interface characterization: An accurate signal propagation time calculation method for UWB breast tumor imaging

    NASA Astrophysics Data System (ADS)

    Wang, Liang; Xiao, Xia; Kikkawa, Takamaro

    2016-12-01

    Radar-based ultrawideband (UWB) microwave imaging is expected to be a safe, low-cost tool for breast cancer detection. However, since radar wave travels at different speeds in different tissues, propagation time is hard to be estimated in heterogeneous breast. Wrongly estimated propagation time leads to error of tumor location in resulting image, aka imaging error. In this paper, we develop a magnetic resonance imaging-aided (MRI-aided) propagation time calculation technique which is independent from radar imaging system but can help decrease the imaging error. The technique can eliminate the influence of the rough interface between fat layer and gland layer in breast and get relative accurate thicknesses of two layers. The propagation time in each layer is calculated and summed. The summed propagation time is used in Confocal imaging algorithm to increase the accuracy of resulting image. 25 patients' breast models with glands of varying size are classified into four categories for imaging simulation tests. Imaging accuracy in terms of tumor location along x-direction has been improved for 21 among 25 cases, as a result, overall around 50% improvement compared to conventional UWB imaging.

  14. A CPW-Fed Circular Wide-Slot UWB Antenna with Wide Tunable and Flexible Reconfigurable Dual Notch Bands

    PubMed Central

    Li, Yingsong; Li, Wenxing; Ye, Qiubo

    2013-01-01

    A coplanar waveguide (CPW)-fed circular slot antenna with wide tunable dual band-notched function and frequency reconfigurable characteristic is designed, and its performance is verified experimentally for ultra-wideband (UWB) communication applications. The dual band-notched function is achieved by using a T-shaped stepped impedance resonator (T-SIR) inserted inside the circular ring radiation patch and by etching a parallel stub loaded resonator (PSLR) in the CPW transmission line, while the wide tunable bands can be implemented by adjusting the dimensions of the T-SIR and the PSLR. The notch band reconfigurable characteristic is realized by integrating three switches into the T-SIR and the PSLR. The numerical and experimental results show that the proposed antenna has a wide bandwidth ranging from 2.7 GHz to 12 GHz with voltage standing wave ratio (VSWR) less than 2, except for the two notch bands operating at 3.8–5.9 GHz and 7.7–9.2 GHz, respectively. In addition, the proposed antenna has been optimized to a compact size and can provide omnidirectional radiation patterns, which are suitable for UWB communication applications. PMID:24222733

  15. A 128-channel 6 mW wireless neural recording IC with spike feature extraction and UWB transmitter.

    PubMed

    Chae, Moo Sung; Yang, Zhi; Yuce, Mehmet R; Hoang, Linh; Liu, Wentai

    2009-08-01

    This paper reports a 128-channel neural recording integrated circuit (IC) with on-the-fly spike feature extraction and wireless telemetry. The chip consists of eight 16-channel front-end recording blocks, spike detection and feature extraction digital signal processor (DSP), ultra wideband (UWB) transmitter, and on-chip bias generators. Each recording channel has amplifiers with programmable gain and bandwidth to accommodate different types of biological signals. An analog-to-digital converter (ADC) shared by 16 amplifiers through time-multiplexing results in a balanced trade-off between the power consumption and chip area. A nonlinear energy operator (NEO) based spike detector is implemented for identifying spikes, which are further processed by a digital frequency-shaping filter. The computationally efficient spike detection and feature extraction algorithms attribute to an auspicious DSP implementation on-chip. UWB telemetry is designed to wirelessly transfer raw data from 128 recording channels at a data rate of 90 Mbit/s. The chip is realized in 0.35 mum complementary metal-oxide-semiconductor (CMOS) process with an area of 8.8 x 7.2 mm(2) and consumes 6 mW by employing a sequential turn-on architecture that selectively powers off idle analog circuit blocks. The chip has been tested for electrical specifications and verified in an ex vivo biological environment.

  16. A CPW-fed circular wide-slot UWB antenna with wide tunable and flexible reconfigurable dual notch bands.

    PubMed

    Li, Yingsong; Li, Wenxing; Ye, Qiubo

    2013-01-01

    A coplanar waveguide (CPW)-fed circular slot antenna with wide tunable dual band-notched function and frequency reconfigurable characteristic is designed, and its performance is verified experimentally for ultra-wideband (UWB) communication applications. The dual band-notched function is achieved by using a T-shaped stepped impedance resonator (T-SIR) inserted inside the circular ring radiation patch and by etching a parallel stub loaded resonator (PSLR) in the CPW transmission line, while the wide tunable bands can be implemented by adjusting the dimensions of the T-SIR and the PSLR. The notch band reconfigurable characteristic is realized by integrating three switches into the T-SIR and the PSLR. The numerical and experimental results show that the proposed antenna has a wide bandwidth ranging from 2.7 GHz to 12 GHz with voltage standing wave ratio (VSWR) less than 2, except for the two notch bands operating at 3.8-5.9 GHz and 7.7-9.2 GHz, respectively. In addition, the proposed antenna has been optimized to a compact size and can provide omnidirectional radiation patterns, which are suitable for UWB communication applications.

  17. Radio data transmission for SCADA

    SciTech Connect

    Frasier, W.E. )

    1989-09-01

    Enron has used such wireless systems as meteor burst radio, 952 MHz multiple address radio, VSAT and L-band satellite, cellular radio and ACSB radio. The company's experience with meteor burst radio communications is discussed in this paper. It indicates good system reliability and consequently all back-up telephone lines have been removed from sites using this system.

  18. DEMONSTRATION BULLETIN: RADIO FREQUENCY HEATING - IIT RESEARCH INSTITUTE

    EPA Science Inventory

    Radio frequency heating (RFH) is a process that uses electromagnetic energy generated by radio waves to heat soil in situ, thereby potentially enhancing the performance of standard soil vapor extraction (SVE) technologies. An RFH system developed by the IIT Research Institute ...

  19. DEMONSTRATION BULLETIN: RADIO FREQUENCY HEATING - KAI TECHNOLOGIES, INC.

    EPA Science Inventory

    Radio frequency heating (RFH) is a process that uses electromagnetic energy in the radio frequency (RF) band to heat soil in situ, thereby potentially enhancing the performance of standard soil vapor extraction (SVE) technologies. An RFH system developed by KAI Technologies, I...

  20. Radio and TV interference extraction for ultrawideband radar

    NASA Astrophysics Data System (ADS)

    Abend, Kenneth; McCorkle, John W.

    1995-06-01

    This paper describes a computationally efficient, high-performance, UWB radar interference suppression algorithm. An adaptive FIR (finite impulse response) prediction-error noise- whitening filter exhibits minimal computational complexity and achieves 30 dB interference reduction per pulse (1 microsecond(s) long) with 16-bit simulated interference. Using measured interference data digitized to 8-bits with a 6.5 effective bit digitizer, collected just north of Washington, DC at the Army Research Laboratory, the technique achieved 20 to 27 dB of reduction. To minimize the computational load, the filter weights are periodically determined from data collected during a fraction of a radar range sweep. These weights are found to be effective for hundreds of subsequent radar pulses. Previous work on an estimate-and-subtract, tone-extraction technique resulted in 20 dB average interference reduction on the same measured data with a computational load linearly related to the number of tones extracted. The adaptive filtering approach uses an over-determined system producing an FIR filter with N taps, independent of the number of interference signals. An iterative technique to reduce the range sidelobes caused by the filter's impulse response is also presented. The computational load of this iterative stage is, at worst, linearly related to the number of targets whose sidelobes are extracted. It is shown that, with a small reduction in performance, the sidelobe reduction can be accomplished with a relatively small increase in the overall computational load. The computational complexity of the proposed technique relative to the estimate-and- subtract technique depends on the signal and interference environment and on the acceptable sidelobe level. A comprehensive radio and TV interference simulator was developed to test the interference suppression algorithm. It avoids difficulties in memory requirements and code complexity typically encountered in high-sample rate, long

  1. Stabilized radio frequency quadrupole

    DOEpatents

    Lancaster, Henry D.; Fugitt, Jock A.; Howard, Donald R.

    1984-01-01

    A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

  2. Stabilized radio frequency quadrupole

    DOEpatents

    Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

    1984-12-25

    Disclosed is a long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator. 5 figs.

  3. Amateur Radio Satellite Communications.

    ERIC Educational Resources Information Center

    Koch, David P.

    The Amateur Radio Satellite Communications project had, as its goal, the assembly of an amateur radio satellite station in a high school physics classroom. Specific objectives were to provide: (1) a special source of interest as a motivator for attracting students and building public relations; (2) a center of interest as a motivator for the study…

  4. Planetary foreshock radio emissions

    NASA Astrophysics Data System (ADS)

    Kuncic, Zdenka; Cairns, Iver H.

    2005-07-01

    The electron foreshock regions upstream of Earth's bow shock and upstream of traveling interplanetary shocks are known to be propitious sites for a variety of energetic particle and plasma wave phenomena, including radio emissions. A quantitative theoretical model has been developed for radio emissions associated with the terrestrial foreshock and for type II radio bursts associated with interplanetary shocks. Here, we generalize this model and apply it to other planetary foreshocks. We present predictions for the levels of planetary foreshock radio emissions and compare these with observations by past and present space missions. One key result is that Mercury can be a strong source of foreshock radio emissions, and this prediction may be testable with the anticipated BepiColombo space mission. Although the terrestrial foreshock radio emissions are the most detectable with existing instruments, our results predict that they are the second strongest in absolute terms, following the Jovian foreshock emissions. Indeed, we predict that the radio instrument on board Ulysses should have detected Jovian foreshock radio emissions, and we suggest that there is some evidence in the data to support this. We also suggest that Cassini was potentially capable of detecting foreshock emissions from Venus during its gravity-assist flybys and may possibly be capable of detecting foreshock emissions from Saturn under favorable solar wind conditions.

  5. Radio Astronomy for Amateurs

    NASA Astrophysics Data System (ADS)

    Quinn, N.; Murdin, P.

    2003-04-01

    Karl Jansky is considered the father of RADIOASTRONOMY. During the 1930s, Jansky worked for the Bell Telephone Laboratories studying the origin of static noise from thunderstorms. During the course of this work he discovered that some signals had an extraterrestrial origin. However, it was Grote Reber, a professional radio engineer and radio amateur, who carried out further investigations. In 1937...

  6. The Radio Jove Project

    NASA Technical Reports Server (NTRS)

    Thieman, J. R.

    2010-01-01

    The Radio love Project is a hands-on education and outreach project in which students, or any other interested individuals or groups build a radio telescope from a kit, operate the radio telescope, transmit the resulting signals through the internet if desired, analyze the results, and share the results with others through archives or general discussions among the observers. Radio love is intended to provide an introduction to radio astronomy for the observer. The equipment allows the user to observe radio signals from Jupiter, the Sun, the galaxy, and Earth-based radiation both natural and man-made. The project was started through a NASA Director's Discretionary Fund grant more than ten years ago. it has continued to be carried out through the dedicated efforts of a group of mainly volunteers. Dearly 1500 kits have been distributed throughout the world. Participation can also be done without building a kit. Pre-built kits are available. Users can also monitor remote radio telescopes through the internet using free downloadable software available through the radiosky.com website. There have been many stories of prize-winning projects, inspirational results, collaborative efforts, etc. We continue to build the community of observers and are always open to new thoughts about how to inspire the observers to still greater involvement in the science and technology associated with Radio Jove.

  7. Writing for Radio.

    ERIC Educational Resources Information Center

    Tupper, Marianna S.

    1995-01-01

    Describes a 24-hour commercial radio station simulation class project for eighth-grade language arts. Students wrote their own scripts, chose music and were disc jockeys on their own music and talk shows, and prepared news and traffic reports. Guest speakers from actual commercial radio came in to discuss issues such as advertising, censorship,…

  8. Film, Radio, and Television.

    ERIC Educational Resources Information Center

    Hardesty, Carolyn, Ed.

    1990-01-01

    This journal issue covers the history of film, radio, and television in Iowa. The first article, "When Pictures and Sound Came to Iowa," summarizes the origin of movies and radio and their early beginnings in Iowa. Using old photographs and measurement charts, the viewing, reading, and listening habits of young people in 1950 and 1958…

  9. Polyethylene Oxide Films Polymerized by Radio Frequency Plasma-Enhanced Chemical Vapour Phase Deposition and Its Adsorption Behaviour of Platelet-Rich Plasma

    NASA Astrophysics Data System (ADS)

    Hu, Wen-Juan; Xie, Fen-Yan; Chen, Qiang; Weng, Jing

    2008-10-01

    We present polyethylene oxide (PEO) functional films polymerized by rf plasma-enhanced vapour chemical deposition (rf-PECVD) on p-Si (100) surface with precursor ethylene glycol dimethyl ether (EGDME) and diluted Ar in pulsed plasma mode. The influences of discharge parameters on the film properties and compounds are investigated. The film structure is analysed by Fourier transform infrared (FTIR) spectroscopy. The water contact angle measurement and atomic force microscope (AFM) are employed to examine the surface polarity and to detect surface morphology, respectively. It is concluded that the smaller duty cycle in pulsed plasma mode contributes to the rich C-O-C (EO) group on the surfaces. As an application, the adsorption behaviour of platelet-rich plasma on plasma polymerization films performed in-vitro is explored. The shapes of attached cells are studied in detail by an optic invert microscope, which clarifies that high-density C-O-C groups on surfaces are responsible for non-fouling adsorption behaviour of the PEO films.

  10. Realistic Radio Communications in Pilot Simulator Training

    NASA Technical Reports Server (NTRS)

    Burki-Cohen, Judith; Kendra, Andrew J.; Kanki, Barbara G.; Lee, Alfred T.

    2000-01-01

    Simulators used for total training and evaluation of airline pilots must satisfy stringent criteria in order to assure their adequacy for training and checking maneuvers. Air traffic control and company radio communications simulation, however, may still be left to role-play by the already taxed instructor/evaluators in spite of their central importance in every aspect of the flight environment. The underlying premise of this research is that providing a realistic radio communications environment would increase safety by enhancing pilot training and evaluation. This report summarizes the first-year efforts of assessing the requirement and feasibility of simulating radio communications automatically. A review of the training and crew resource/task management literature showed both practical and theoretical support for the need for realistic radio communications simulation. A survey of 29 instructor/evaluators from 14 airlines revealed that radio communications are mainly role-played by the instructor/evaluators. This increases instructor/evaluators' own workload while unrealistically lowering pilot communications load compared to actual operations, with a concomitant loss in training/evaluation effectiveness. A technology review searching for an automated means of providing radio communications to and from aircraft with minimal human effort showed that while promising, the technology is still immature. Further research and the need for establishing a proof-of-concept are also discussed.

  11. Radio efficiency of pulsars

    SciTech Connect

    Szary, Andrzej; Melikidze, George I.; Gil, Janusz; Zhang, Bing; Xu, Ren-Xin E-mail: zhang@physics.unlv.edu

    2014-03-20

    We investigate radio emission efficiency, ξ, of pulsars and report a near-linear inverse correlation between ξ and the spin-down power, E-dot , as well as a near-linear correlation between ξ and pulsar age, τ. This is a consequence of very weak, if any, dependences of radio luminosity, L, on pulsar period, P, and the period derivative, P-dot , in contrast to X-ray or γ-ray emission luminosities. The analysis of radio fluxes suggests that these correlations are not due to a selection effect, but are intrinsic to the pulsar radio emission physics. We have found that, although with a large variance, the radio luminosity of pulsars is ≈10{sup 29} erg s{sup –1}, regardless of the position in the P-- P-dot diagram. Within such a picture, a model-independent statement can be made that the death line of radio pulsars corresponds to an upper limit in the efficiency of radio emission. If we introduce the maximum value for radio efficiency into the Monte Carlo-based population syntheses we can reproduce the observed sample using the random luminosity model. Using the Kolmogorov-Smirnov test on a synthetic flux distribution reveals a high probability of reproducing the observed distribution. Our results suggest that the plasma responsible for generating radio emission is produced under similar conditions regardless of pulsar age, dipolar magnetic field strength, and spin-down rate. The magnetic fields near the pulsar surface are likely dominated by crust-anchored, magnetic anomalies, which do not significantly differ among pulsars, leading to similar conditions for generating electron-positron pairs necessary to power radio emission.

  12. RESOLVING THE BRIGHT HCN(1–0) EMISSION TOWARD THE SEYFERT 2 NUCLEUS OF M51: SHOCK ENHANCEMENT BY RADIO JETS AND WEAK MASING BY INFRARED PUMPING?

    SciTech Connect

    Matsushita, Satoki; Trung, Dinh-V-; Boone, Frédéric; Krips, Melanie; Lim, Jeremy; Muller, Sebastien

    2015-01-20

    We present high angular resolution observations of the HCN(1-0) emission (at ∼1'' or ∼34 pc), together with CO J = 1-0, 2-1, and 3-2 observations, toward the Seyfert 2 nucleus of M51 (NGC 5194). The overall HCN(1-0) distribution and kinematics are very similar to that of the CO lines, which have been indicated as the jet-entrained molecular gas in our past observations. In addition, high HCN(1-0)/CO(1-0) brightness temperature ratio of about unity is observed along the jets, similar to that observed at the shocked molecular gas in our Galaxy. These results strongly indicate that both diffuse and dense gases are entrained by the jets and outflowing from the active galactic nucleus. The channel map of HCN(1-0) at the systemic velocity shows a strong emission right at the nucleus, where no obvious emission has been detected in the CO lines. The HCN(1-0)/CO(1-0) brightness temperature ratio at this region reaches >2, a value that cannot be explained considering standard physical/chemical conditions. Based on our calculations, we suggest infrared pumping and possibly weak HCN masing, but still requiring an enhanced HCN abundance for the cause of this high ratio. This suggests the presence of a compact dense obscuring molecular gas in front of the nucleus of M51, which remains unresolved at our ∼1'' (∼34 pc) resolution, and consistent with the Seyfert 2 classification picture.

  13. Private Land Mobile Radio Services--Federal Communications Commission. Final rule.

    PubMed

    1982-09-16

    The Commission adopts a Second Report and Order releasing reserved radio spectrum in the 806-821/851-866 MHz bands for Private Land Mobile Radio Service use. The rules adopted provide enhanced flexibility in radio system design and user options. The action is necessary to satisfy land mobile spectrum needs across the country.

  14. The infrared properties of the GPS and CSS radio sources

    NASA Astrophysics Data System (ADS)

    O'Dea, C. P.

    2016-02-01

    I review the results of three Spitzer studies of GHz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio galaxies. The luminosity of the IR continuum and the high ionization lines confirm that some GPS/CSS can have central engines which are similar to those of the extended powerful radio sources. This is consistent with the hypothesis that some GPS/CSS can evolve to become the large-scale sources. Warm H_2 is common in the GPS/CSS sources consistent with feedback via jet-ISM interaction. The GPS/CSS seem to have higher star formation rates than typical (2JY + 3CRR) radio sources. This should be confirmed with a larger sample. If compact sources interact with dense, clumpy star forming clouds and if the interaction with the dense medium sufficiently enhances the radio power, these star forming galaxies with enhanced radio emission will be selected for the current bright samples of GPS and CSS sources. This will increase the number of GPS and CSS sources which are observed to be forming stars. If radio sources have longer lives and/or star formation is more common in large radio galaxies, the need for a new population of star forming compact sources with enhanced radio emission is reduced.

  15. Simple pre-distortion schemes for improving the power efficiency of SOA-based IR-UWB over fiber systems

    NASA Astrophysics Data System (ADS)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2017-01-01

    In this paper, we investigate the usage of SOA for reach extension of an impulse radio over fiber system. Operating in the saturated regime translates into strong nonlinearities and spectral distortions, which drops the power efficiency of the propagated pulses. After studying the SOA response versus operating conditions, we have enhanced the system performance by applying simple analog pre-distortion schemes for various derivatives of the Gaussian pulse and their combination. A novel pulse shape has also been designed by linearly combining three basic Gaussian pulses, offering a very good spectral efficiency (> 55 %) for a high power (0 dBm) at the amplifier input. Furthermore, the potential of our technique has been examined considering a 1.5 Gbps-OOK and 0.75 Gbps-PPM modulation schemes. Pre-distortion proved an advantage for a large extension of optical link (150 km), with an inline amplification via SOA at 40 km.

  16. 75 FR 10439 - Cognitive Radio Technologies and Software Defined Radios

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... COMMISSION 47 CFR Part 2 Cognitive Radio Technologies and Software Defined Radios AGENCY: Federal... implement security features in software defined radios (SDRs). While, the Commission dismisses this petition... Order 1. On March 17, 2005, the Commission adopted the Cognitive Radio Report and Order, 70 FR...

  17. Radio broadcasting via satellite

    NASA Astrophysics Data System (ADS)

    Helm, Neil R.; Pritchard, Wilbur L.

    1990-10-01

    Market areas offering potential for future narrowband broadcast satellites are examined, including international public diplomacy, government- and advertising-supported, and business-application usages. Technical issues such as frequency allocation, spacecraft types, transmission parameters, and radio receiver characteristics are outlined. Service and system requirements, advertising revenue, and business communications services are among the economic issues discussed. The institutional framework required to provide an operational radio broadcast service is studied, and new initiatives in direct broadcast audio radio systems, encompassing studies, tests, in-orbit demonstrations of, and proposals for national and international commercial broadcast services are considered.

  18. Design and Analysis of Miniaturized Microstrip Patch Antenna with Metamaterials Based on Modified Split-Ring Resonator for UWB Applications

    NASA Astrophysics Data System (ADS)

    Khedrouche, D.; Bougoutaia, T.; Hocini, A.

    2016-11-01

    In this paper, a miniaturized microstrip patch antenna using a negative index metamaterial with modified split-ring resonator (SRR) unit cells is proposed for ultra-wideband (UWB) applications. The new design of metamaterial based microstrip patch antenna has been optimized to provide an improved bandwidth and multiple frequency operations. All the antenna performance parameters are presented in response-graphs. Also it is mentioned that the physical dimensions of the metamaterial based patch antenna are very small, which is convenient to modern communication. A 130 % bandwidth, covering the frequency band of 2.9-13.5 GHz, (for return loss less than or equal -10 dB) is achieved, which allow the antenna to operate in the Federal Communication Commission (FCC) band. In addition, the antenna has a good radiation pattern in the ultra-wide band spectrum, and it is nearly omnidirectional.

  19. A human body model for efficient numerical characterization of UWB signal propagation in wireless body area networks.

    PubMed

    Lim, Hooi Been; Baumann, Dirk; Li, Er-Ping

    2011-03-01

    Wireless body area network (WBAN) is a new enabling system with promising applications in areas such as remote health monitoring and interpersonal communication. Reliable and optimum design of a WBAN system relies on a good understanding and in-depth studies of the wave propagation around a human body. However, the human body is a very complex structure and is computationally demanding to model. This paper aims to investigate the effects of the numerical model's structure complexity and feature details on the simulation results. Depending on the application, a simplified numerical model that meets desired simulation accuracy can be employed for efficient simulations. Measurements of ultra wideband (UWB) signal propagation along a human arm are performed and compared to the simulation results obtained with numerical arm models of different complexity levels. The influence of the arm shape and size, as well as tissue composition and complexity is investigated.

  20. Eratosthenes via Ham Radio

    ERIC Educational Resources Information Center

    Koser, John F.

    1975-01-01

    A secondary geology class used Eratosthenes' method for measuring the circumference of the earth by comparing their measurements of the shadow of a vertical rod to the measurements made by another person contacted by ham radio. (MLH)

  1. Unveiling the radio cosmos

    NASA Astrophysics Data System (ADS)

    Vanderlinde, Keith

    2017-02-01

    Using a radio telescope with no moving parts, the dark energy speeding up the expansion of the Universe can be probed in unprecedented detail, says Keith Vanderlinde, on behalf of the CHIME collaboration.

  2. Fast Radio Bursts

    NASA Astrophysics Data System (ADS)

    Kaspi, Victoria M.

    2017-01-01

    Fast Radio Bursts (FRBs) are a recently discovered phenomenon consisting of short (few ms) bursts of radio waves that have dispersion measures that strongly suggest an extragalactic and possibly cosmological origin. Current best estimates for the rate of FRBs is several thousand per sky per day at radio frequencies near 1.4 GHz. Even with so high a rate, to date, fewer than 20 FRBs have been reported, with one source showing repeated bursts. In this talk I will describe known FRB properties including what is known about the lone repeating source, as well as models for the origin of these mysterious events. I will also describe the CHIME radio telescope, currently under construction in Canada. Thanks to its great sensitivity and unprecedented field-of-view, CHIME promises major progress on FRBs.

  3. Packet Radio for Library Automation.

    ERIC Educational Resources Information Center

    Brownrigg, Edwin B.; And Others

    1984-01-01

    This tutorial on packet radio (communication system using radio and digital packet-switching technology) highlights radio transmission of data, brief history, special considerations in applying packet radio to library online catalogs, technology, defining protocol at physical and network levels, security, geographic coverage, and components. (A…

  4. Soldier’s Radio

    DTIC Science & Technology

    1992-02-14

    individual soldier. "t’s primary use is by individuals in squads or small units, but may also be used to interconnect into local and wide area...Velopilnq the concept for the Soldier’s Radio. The operation of the SR can be partitioned into two areas. The architecture required to provide intra- squad ... SQUAD CONMECTrVITY The basic radio ccmmunications architectures suitable for :cnsideration for the SR intra- squad operations include the Net, .tar

  5. The Radio JOVE Project

    NASA Astrophysics Data System (ADS)

    Garcia, L.; Thieman, J.; Higgins, C.

    1999-09-01

    Radio JOVE is an interactive educational activity which brings the radio sounds of Jupiter and the Sun to students, teachers, and the general public. This is accomplished through the construction of a simple radio telescope kit and the use of a real-time radio observatory on the Internet. Our website (http://radiojove.gsfc.nasa.gov/) will contain science information, instruction manuals, observing guides, and education resources for students and teachers. Our target audience is high school science classes, but subjects can be tailored to college undergraduate physics and astronomy courses or even to middle school science classes. The goals of the project are: 1) Educate people about planetary and solar radio astronomy, space physics, and the scientific method 2) Provide teachers and students with a hands-on radio astronomy exercise as a science curriculum support activity by building and using a simple radio telescope receiver/antenna kit 3) Create the first ever online radio observatory which provides real-time data for those with internet access 4) Allow interactions among participating schools by facilitating exchanges of ideas, data, and observing experiences. Our current funding will allow us to impact 100 schools by partially subsidizing their participation in the program. We expect to expand well beyond this number as publicity and general interest increase. Additional schools are welcome to fully participate, but we will not be able to subsidize their kit purchases. We hope to make a wide impact among the schools by advertising through appropriate newsletters, space grant consortia, the INSPIRE project (http://image.gsfc.nasa.gov/poetry/inspire/), electronic links, and science and education meetings. We would like to acknoledge support from the NASA/GSFC Director's Discretionary Fund, the STScI IDEAS grant program and the NASA/GSFC Space Science Data Operations Office.

  6. Radio spectrum surveillance station

    NASA Technical Reports Server (NTRS)

    Hersey, D. R.

    1979-01-01

    The paper presents a general and functional description of a low-cost surveillance station designed as the first phase of NASA's program to develop a radio spectrum surveillance capability for deep space stations for identifying radio frequency interference sources. The station described has identified several particular interferences and is yielding spectral signature data which, after cataloging, will serve as a library for rapid identification of frequently observed interference. Findings from the use of the station are discussed.

  7. Radio observations of solar eclipse.

    NASA Astrophysics Data System (ADS)

    Liu, Yuying; Fu, Qijun

    1998-09-01

    For radio astronomy, a solar eclipse provides an opportunity for making solar radio observations with high one-dimension spatial resolution. The radio observation of a solar eclipse has played an important role in solar radio physics. Some important factors for radio observation of a solar eclipse are introduced and analysed. Solar eclipse radio observation has also played an important role in the progress of solar radio atronomy in China. The solar eclipses of 1958, 1968, 1980 and 1987, which were observed in China, are introduced, and the main results of these observations are briefly shown.

  8. Computational Techniques in Radio Neutrino Event Reconstruction

    NASA Astrophysics Data System (ADS)

    Beydler, M.; ARA Collaboration

    2016-03-01

    The Askaryan Radio Array (ARA) is a high-energy cosmic neutrino detector constructed with stations of radio antennas buried in the ice at the South Pole. Event reconstruction relies on the analysis of the arrival times of the transient radio signals generated by neutrinos interacting within a few kilometers of the detector. Because of its depth dependence, the index of refraction in the ice complicates the interferometric directional reconstruction of possible neutrino events. Currently, there is an ongoing endeavor to enhance the programs used for the time-consuming computations of the curved paths of the transient wave signals in the ice as well as the interferometric beamforming. We have implemented a fast, multi-dimensional spline table lookup of the wave arrival times in order to enable raytrace-based directional reconstructions. Additionally, we have applied parallel computing across multiple Graphics Processing Units (GPUs) in order to perform the beamforming calculations quickly.

  9. Astrometry of southern radio sources.

    PubMed

    White, G L; Jauncey, D L; Harvey, B R; Savage, A; Gulkis, S; Preston, R A; Peterson, B A; Reynolds, J E; Nicolson, G D; Malin, D F

    1991-01-01

    An overview is presented of a number of astrometry and astrophysics programs based on radio sources from the Parkes 2.7 GHz catalogues. The programs cover the optical identification and spectroscopy of flat-spectrum Parkes sources and the determination of their milliarc-second radio structures and positions. Work is also in progress to tie together the radio and Hipparcos positional reference frames. A parallel program of radio and optical astrometry of southern radio stars is also under way.

  10. TDM-PON compatible generation of 10 Gbps NRZ and 1.25 Gbps UWB signals by a single light source.

    PubMed

    Malekizandi, Mohammadreza; Le, Quang Trung; Emsia, Ali; Briggmann, Dieter; Chipouline, Arkadi; Küppers, Franko

    2016-07-25

    A novel and cost-efficient technique is presented to generate non-return-to-zero (NRZ) and ultra-wideband (UWB) signals in different time slots of time division multiplexing-passive optical network (TDM-PON) by using a single chirped controlled semiconductor laser associated with an optical bandpass filter. In this technique, the chirp of the laser is controlled by different bias burst amplitudes (BBA) for different time slots. Through the proper selection of the burst amplitudes, 10 Gbps NRZ and 1.25 Gbps UWB signals are generated in different time slots. Principle of operation is discussed, the complete chirp behavior of the laser is experimentally investigated, data transmission of the generated signals is demonstrated and bit-error-rate (BER) level of 10-9 is achieved.

  11. Performance Enhancements of Ranging Radio Aided Navigation

    DTIC Science & Technology

    2009-03-01

    c22 c23 c31 c32 c33 37775 (2.1) pb = Cbap a (2.2) The DCM has the following properties if used with a right hand Cartesian frame: 1. Det(Cba) Cba...3 F11m = 26666666664 03 I3 03 03 03 CneGC e n 2Cne eieCen (fn) Cnb 03 03 03 (Cne!eie) 03 Cnb 03 03 03 1a I3 03 03 03 03 03 1 b I3 ...represents the distance to the landmark and is found from the z component of yn, pbcam, and s¯ c. d = [yn]z pn+Cnbp b cam z [CnbC b cs ¯ c]z (3.27) Now

  12. Cognitive Radio will revolutionize American transportation

    ScienceCinema

    None

    2016-07-12

    Cognitive Radio will revolutionize American transportation. Through smart technology, it will anticipate user needs; detect available bandwidths and frequencies then seamlessly connect vehicles, infrastructures, and consumer devices; and it will support the Department of Transportation IntelliDrive Program, helping researchers, auto manufacturers, and Federal and State officials advance the connectivity of US transportation systems for improved safety, mobility, and environmental conditions. Using cognitive radio, a commercial vehicle will know its driver, onboard freight and destination route. Drivers will save time and resources communicating with automatic toll booths and know ahead of time whether to stop at a weigh station or keep rolling. At accident scenes, cognitive radio sensors on freight and transportation modes can alert emergency personnel and measure on-site, real-time conditions such as a chemical leak. The sensors will connect freight to industry, relaying shipment conditions and new delivery schedules. For industry or military purposes, cognitive radio will enable real-time freight tracking around the globe and its sensory technology can help prevent cargo theft or tampering by alerting shipper and receiver if freight is tampered with while en route. For the average consumer, a vehicle will tailor the transportation experience to the passenger such as delivering age-appropriate movies via satellite. Cognitive radio will enhance transportation safety by continually sensing what is important to the user adapting to its environment and incoming information, and proposing solutions that improve mobility and quality of life.

  13. Cognitive Radio will revolutionize American transportation

    SciTech Connect

    2013-07-22

    Cognitive Radio will revolutionize American transportation. Through smart technology, it will anticipate user needs; detect available bandwidths and frequencies then seamlessly connect vehicles, infrastructures, and consumer devices; and it will support the Department of Transportation IntelliDrive Program, helping researchers, auto manufacturers, and Federal and State officials advance the connectivity of US transportation systems for improved safety, mobility, and environmental conditions. Using cognitive radio, a commercial vehicle will know its driver, onboard freight and destination route. Drivers will save time and resources communicating with automatic toll booths and know ahead of time whether to stop at a weigh station or keep rolling. At accident scenes, cognitive radio sensors on freight and transportation modes can alert emergency personnel and measure on-site, real-time conditions such as a chemical leak. The sensors will connect freight to industry, relaying shipment conditions and new delivery schedules. For industry or military purposes, cognitive radio will enable real-time freight tracking around the globe and its sensory technology can help prevent cargo theft or tampering by alerting shipper and receiver if freight is tampered with while en route. For the average consumer, a vehicle will tailor the transportation experience to the passenger such as delivering age-appropriate movies via satellite. Cognitive radio will enhance transportation safety by continually sensing what is important to the user adapting to its environment and incoming information, and proposing solutions that improve mobility and quality of life.

  14. An Analysis of Electromagnetic Interference (EMI) of Ultra Wideband(UWB) and IEEE 802.11A Wireless Local Area Network (WLAN) Employing Orthogonal Frequency Division Multiplexing (OFDM)

    DTIC Science & Technology

    2004-03-01

    802.11 Networks, 2d ed., SAMS, Indianapolis, IN, 2002. [HäH02] M. Hämäläinen, V. Hovinen, R. Tesi , J.H.J. Iinatti, and M. Latva-aho, On the UWB...Fi) Networking Handbook, McGraw-Hill: NY, 2003. [Sal02]. M.P. Salud , Investigation of RF Emissions from Wireless Networks as a Threat to Avionic

  15. Self Organization of Wireless Sensor Networks Using Ultra-Wideband Radios

    SciTech Connect

    Nekoogar, F; Dowla, F; Spiridon, A

    2004-07-19

    Ultra-wideband (UWB) technology has proven to be useful in short range, high data rate, robust, and low power communications. These features can make UWB systems ideal candidates for reliable data communications between nodes of a wireless sensor network (WSN). However, the low powered UWB pulses can be significantly degraded by channel noise, inter-node interference, and intentional jamming. In this paper we present a novel interference suppression technique for UWB based WSNs that promises self-organization in terms of power conservation, scalability, and channel estimation for the entire distributed network.

  16. Radio data archiving system

    NASA Astrophysics Data System (ADS)

    Knapic, C.; Zanichelli, A.; Dovgan, E.; Nanni, M.; Stagni, M.; Righini, S.; Sponza, M.; Bedosti, F.; Orlati, A.; Smareglia, R.

    2016-07-01

    Radio Astronomical Data models are becoming very complex since the huge possible range of instrumental configurations available with the modern Radio Telescopes. What in the past was the last frontiers of data formats in terms of efficiency and flexibility is now evolving with new strategies and methodologies enabling the persistence of a very complex, hierarchical and multi-purpose information. Such an evolution of data models and data formats require new data archiving techniques in order to guarantee data preservation following the directives of Open Archival Information System and the International Virtual Observatory Alliance for data sharing and publication. Currently, various formats (FITS, MBFITS, VLBI's XML description files and ancillary files) of data acquired with the Medicina and Noto Radio Telescopes can be stored and handled by a common Radio Archive, that is planned to be released to the (inter)national community by the end of 2016. This state-of-the-art archiving system for radio astronomical data aims at delegating as much as possible to the software setting how and where the descriptors (metadata) are saved, while the users perform user-friendly queries translated by the web interface into complex interrogations on the database to retrieve data. In such a way, the Archive is ready to be Virtual Observatory compliant and as much as possible user-friendly.

  17. Statistical radio astronomy of the 21st century

    NASA Astrophysics Data System (ADS)

    Pariiskii, Yu. N.; Berlin, A. B.; Bursov, N. N.; Nizhel'skii, N. A.; Semenova, T. A.; Temirova, A. V.; Tsybulev, P. G.

    2015-06-01

    The exponential development of radio-astronomy methods (sensitivity, resolution, depth of surveys, etc) has led to the need for new methods aimed at distinguishing weak signals in the midst of numerous background signals, as has long been the case for radio astronomy at meter wavelengths. Centimeter-wavelength data accumulated with existing radio telescopes (such as the RATAN-600 reflector—the largest radio telescope in Russia) are presented, and expected problems for major new radio telescopes of the 21st century, such as the Square Kilometer Array, are discussed. The effectiveness of using certain tested methods to derive astrophysically important results through reasonable statistical processing of large datasets is shown. In experiments conducted with RATAN-600, these methods lead to an enhancement in sensitivity by an order of magnitude compared with the sensitivity of a resolving element.

  18. Comets at radio wavelengths

    NASA Astrophysics Data System (ADS)

    Crovisier, Jacques; Bockelée-Morvan, Dominique; Colom, Pierre; Biver, Nicolas

    2016-11-01

    Comets are considered as the most primitive objects in the Solar System. Their composition provides information on the composition of the primitive solar nebula, 4.6 Gyr ago. The radio domain is a privileged tool to study the composition of cometary ices. Observations of the OH radical at 18 cm wavelength allow us to measure the water production rate. A wealth of molecules (and some of their isotopologues) coming from the sublimation of ices in the nucleus have been identified by observations in the millimetre and submillimetre domains. We present an historical review on radio observations of comets, focusing on the results from our group, and including recent observations with the Nançay radio telescope, the IRAM antennas, the Odin satellite, the Herschel space observatory, ALMA, and the MIRO instrument aboard the Rosetta space probe.

  19. High redshift radio galaxies

    NASA Technical Reports Server (NTRS)

    Mccarthy, Patrick J.

    1993-01-01

    High redshift galaxies that host powerful radio sources are examined. An overview is presented of the content of radio surveys: 3CR and 3CRR, 4C and 4C/USS, B2/1 Jy, MG, MRC/1Jy, Parkes/PSR, B3, and ESO Key-Project. Narrow-line radio galaxies in the visible and UV, the source of ionization and excitation of the emission lines, emission-line luminosities, morphology of the line-emitting gas, physical properties and energetics, kinematics of the line-emitting gas, and implications from the emission lines are discussed. The morphologies and environments of the host galaxies, the alignment effect, and spectral energy distributions and ages are also examined.

  20. Radio coverage statistics.

    PubMed

    Lynn, W

    1984-01-01

    The Clearinghouse on Development Communication surveyed 135 countries in Asia, Africa, Europe, North and South America, for U.S.A.I.D., to determine the number of radio and television broadcast stations and receivers. Some of the data were obtained from the World Factbook, the World Radio and TV Handbook, and the World Radio and T.V. Facts and Figures, from 1979 to 1981. In those countries where stations are privately owned, audience surveys are often available. In 2 out of 3 developing countries, however, stations are government owned, and no such information is available. Numbers of receivers can sometimes be ascertained from receiver license applications. There is a need for more complete information on broadcast demographics, listening and viewing patterns by the community of world development program personnel.

  1. Radio frequency spectrum management

    NASA Astrophysics Data System (ADS)

    Sujdak, E. J., Jr.

    1980-03-01

    This thesis is a study of radio frequency spectrum management as practiced by agencies and departments of the Federal Government. After a brief introduction to the international agency involved in radio frequency spectrum management, the author concentrates on Federal agencies engaged in frequency management. These agencies include the National Telecommunications and Information Administration (NTIA), the Interdepartment Radio Advisory Committee (IRAC), and the Department of Defense (DoD). Based on an analysis of Department of Defense frequency assignment procedures, recommendations are given concerning decentralizing military frequency assignment by delegating broader authority to unified commanders. This proposal includes a recommendation to colocate the individual Service frequency management offices at the Washington level. This would result in reduced travel costs, lower manpower requirements, and a common tri-Service frequency management data base.

  2. Planetary radio waves

    NASA Technical Reports Server (NTRS)

    Goertz, C. K.

    1986-01-01

    Three planets, the earth, Jupiter and Saturn are known to emit nonthermal radio waves which require coherent radiation processes. The characteristic features (frequency spectrum, polarization, occurrence probability, radiation pattern) are discussed. Radiation which is externally controlled by the solar wind is distinguished from internally controlled radiation which only originates from Jupiter. The efficiency of the externally controlled radiation is roughly the same at all three planets (5 x 10 to the -6th) suggesting that similar processes are active there. The maser radiation mechanism for the generation of the radio waves and general requirements for the mechanism which couples the power generator to the region where the radio waves are generated are briefly discussed.

  3. Radio Emission from Supernovae

    SciTech Connect

    Weiler, Kurt W.; Panagia, Nino; Sramek, Richard A.; Van Dyk, Schuyler D.; Stockdale, Christopher J.; Kelley, Matthew T.

    2009-05-03

    Study of radio supernovae over the past 27 years includes more than three dozen detected objects and more than 150 upper limits. From this work it is possible to identify classes of radio properties, demonstrate conformance to and deviations from existing models, estimate the density and structure of the circumstellar material and, by inference, the evolution of the presupernova stellar wind, and reveal the last stages of stellar evolution before explosion. It is also possible to detect ionized hydrogen along the line of sight, to demonstrate binary properties of the presupernova stellar system, and to detect dumpiness of the circumstellar material.

  4. Radio Observations of Meteors.

    PubMed

    Millman, P M

    1954-08-27

    To summarize, we find that the radio technique of meteor observation enables us to extend the systematic recording of meteor rates down to the 9th or 10th magnitude; to determine satisfactory heights and velocities on a scale previously impossible; to calculate the orbits of meteor showers and individual meteors, in particular those that appear only in the daytime; and to study wind drift and fine structure in the ionosphere. The radio observations have quite definitely indicated that down to the 9th magnitude, corresponding to particles approximately 1 mm in diameter, meteors are members of the solar system and do not come from interstellar space.

  5. Sensors Locate Radio Interference

    NASA Technical Reports Server (NTRS)

    2009-01-01

    After receiving a NASA Small Business Innovation Research (SBIR) contract from Kennedy Space Center, Soneticom Inc., based in West Melbourne, Florida, created algorithms for time difference of arrival and radio interferometry, which it used in its Lynx Location System (LLS) to locate electromagnetic interference that can disrupt radio communications. Soneticom is collaborating with the Federal Aviation Administration (FAA) to install and test the LLS at its field test center in New Jersey in preparation for deploying the LLS at commercial airports. The software collects data from each sensor in order to compute the location of the interfering emitter.

  6. Radio astronomy with microspacecraft

    NASA Technical Reports Server (NTRS)

    Collins, D.

    2001-01-01

    A dynamic constellation of microspacecraft in lunar orbit can carry out valuable radio astronomy investigations in the frequency range of 30kHz--30MHz, a range that is difficult to explore from Earth. In contrast to the radio astronomy ivestigations that have flown on individual spacecraft, the four microspacecraft together with a carrier spacecraft, which transported them to lunar orbit, form an interferometer with far superior angular resolution. Use of microspacecraft allows the entire constellation to be launched with a Taurus-class vehicle. Also distinguishing this approach is that the Moon is used as needed to shield the constellation from RF interference from the Earth and Sun.

  7. A radio frequency coaxial feedthrough

    DOEpatents

    Owens, T.L.

    1987-12-07

    An improved radio frequency coaxial transmission line vacuum feedthrough is provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflection from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits the voltage and power handling capabilities of a feedthrough.

  8. Prism beamswitch for radio telescopes.

    PubMed

    Payne, J M; Ulich, B L

    1978-12-01

    A dielectric prism and switching mechanism have been constructed for beamswitching a Cassegrain radio telescope. Spatially extended radio sources may be mapped without significant confusion utilizing the sensitivity and stability inherent in the conventional Dicke radiometer.

  9. Svetloe Radio Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Smolentsev, Sergey; Rahimov, Ismail

    2013-01-01

    This report summarizes information about the Svetloe Radio Astronomical Observatory activities in 2012. Last year, a number of changes took place in the observatory to improve some technical characteristics and to upgrade some units to their required status. The report provides an overview of current geodetic VLBI activities and gives an outlook for the future.

  10. Zelenchukskaya Radio Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Smolentsev, Sergey; Dyakov, Andrei

    2013-01-01

    This report summarizes information about Zelenchukskaya Radio Astronomical Observatory activities in 2012. Last year a number of changes took place in the observatory to improve some technical characteristics and to upgrade some units to the required status. The report provides an overview of current geodetic VLBI activities and gives an outlook for the future.

  11. RADIO RANGING DEVICE

    DOEpatents

    Nieset, R.T.

    1961-05-16

    A radio ranging device is described. It utilizes a super regenerative detector-oscillator in which echoes of transmitted pulses are received in proper phase to reduce noise energy at a selected range and also at multiples of the selected range.

  12. Community Radio in Canada.

    ERIC Educational Resources Information Center

    Canadian Broadcasting Corp., Ottawa (Ontario).

    Results are presented of a survey of 20 community radio organizations operating in Canada. For each of the 20 agencies, information is provided relating to: (1) the name and address of the organization; (2) the name and population of the community served; (3) the station's call letters, frequency, and power; (4) the date of the station's license;…

  13. Radio Channel Simulator (RCSM)

    SciTech Connect

    2007-01-31

    This is a simulation package for making site specific predictions of radio signal strength. The software computes received power at discrete grid points as a function of the transmitter location and propagation environment. It is intended for use with wireless network simulation packages and to support wireless network deployments.

  14. Albanian: Basic Radio Communications.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This volume has been designed as a supplement to a course in Albanian developed by the Defense Language Institute. The emphasis in this text is placed on radio communications instruction. The volume is divided into five exercises, each of which contains a vocabulary, dictation, and an air-to-ground communications procedure conducted in Albanian…

  15. Torun Radio Astronomy Observatory

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Torun Center for Astronomy is located at Piwnice, 15 km north of Torun, Poland. A part of the Faculty of Physics and Astronomy of the Nicolaus Copernicus University, it was created by the union of Torun Radio Astronomy Observatory (TRAO) and the Institute of Astronomy on 1 January 1997....

  16. Educational Broadcasting--Radio.

    ERIC Educational Resources Information Center

    Ahamed, Uvais; Grimmett, George

    This manual is intended for those who must conduct educational radio broadcasting training courses in Asia-Pacific countries without the resources of experienced personnel, as well as for individuals to use in self-learning situations. The selection of material has been influenced by the need to use broadcasting resources effectively in programs…

  17. Community Control of Local Radio.

    ERIC Educational Resources Information Center

    Lewis, Peter M.

    This study was designed to determine to what extent local communities control the local radio which serves them, by what formal mechanisms their control is secured, and the underlying assumptions and goals which govern the practice of the professionals who have charge of the facilities. Two British radio stations, BBC Radio Bristol and the…

  18. Ham Radio is Mir Magic.

    ERIC Educational Resources Information Center

    Evans, Gary

    1997-01-01

    Presents a classroom activity in which students communicated with U.S. and Russian astronauts via ham radio while they were in orbit on the space station Mir. Gives suggestions for other ham radio classroom activities as well as names of organizations, publications, and grant programs that teachers can access to help in bring ham radio into their…

  19. Radio: Your Publics Are Listening!

    ERIC Educational Resources Information Center

    Marx, Gary

    The purpose of this booklet is to provide school board members, administrators, teachers, and others interested in education with an understanding of radio, how it works, and how school systems can take advantage of the communications possibilities offered by radio. After providing background information on radio as a mass communications medium…

  20. The interplay between radio galaxies and cluster environment

    NASA Astrophysics Data System (ADS)

    Magliocchetti, Manuela; Brüggen, Marcus

    2007-07-01

    By combining the REFLEX and NORAS cluster data sets with the NVSS radio catalogue, we obtain a sample of 145, z < 0.3, X-ray-selected clusters brighter than 3 × 10-12 erg s-1cm-2 that show a central radio emission above 3 mJy. For virial masses Mvir <~ 1014.5Msolar, 11 clusters out of 12 (corresponding to 92 per cent of the systems) are inhabited by a central radio source. This fraction decreases with higher masses as ~ M-0.4vir. If this decrease is a selection effect, it suggests that the majority of X-ray-selected clusters host in their centre a radio source brighter than ~1020 WHz-1sr-1. A division of the sample into clusters harbouring either point-like or an extended radio-loud active galactic nucleus (AGN) reveals that the steepening of the LX -T relation for low-temperature clusters is strongly associated with the presence of central radio objects with extended jets and/or lobe structures. In the latter case, LX ~ T4 while for point-like sources one recovers an approximately self-similar relation LX ~ T2.3. Monte Carlo simulations show that the steepening of the LX -T relation is not caused by clusters being underluminous in the X-ray band, but rather by overheating, most likely caused by the interplay between the extended radio structures and the intracluster medium. In the case of low-mass systems, we also find a tight correlation between radio luminosity and cluster temperature. The effects of the central radio source on the thermal state of a cluster become less important with increasing cluster mass. The presence of radio sources with extended structures (61, corresponding to ~42 per cent of the sample) is enhanced in X-ray luminous clusters with respect to `field' radio-loud AGN. Furthermore, we find that the luminosity distribution of the cluster radio population differs from that of all radio sources, as there is a deficit of low-luminosity (LR <~ 1022 WHz-1sr-1) objects, while the number of high-luminosity ones is boosted. The net effect on the

  1. Collaborative Beamfocusing Radio (COBRA)

    NASA Astrophysics Data System (ADS)

    Rode, Jeremy P.; Hsu, Mark J.; Smith, David; Husain, Anis

    2013-05-01

    A Ziva team has recently demonstrated a novel technique called Collaborative Beamfocusing Radios (COBRA) which enables an ad-hoc collection of distributed commercial off-the-shelf software defined radios to coherently align and beamform to a remote radio. COBRA promises to operate even in high multipath and non-line-of-sight environments as well as mobile applications without resorting to computationally expensive closed loop techniques that are currently unable to operate with significant movement. COBRA exploits two key technologies to achieve coherent beamforming. The first is Time Reversal (TR) which compensates for multipath and automatically discovers the optimal spatio-temporal matched filter to enable peak signal gains (up to 20 dB) and diffraction-limited focusing at the intended receiver in NLOS and severe multipath environments. The second is time-aligned buffering which enables TR to synchronize distributed transmitters into a collaborative array. This time alignment algorithm avoids causality violations through the use of reciprocal buffering. Preserving spatio-temporal reciprocity through the TR capture and retransmission process achieves coherent alignment across multiple radios at ~GHz carriers using only standard quartz-oscillators. COBRA has been demonstrated in the lab, aligning two off-the-shelf software defined radios over-the-air to an accuracy of better than 2 degrees of carrier alignment at 450 MHz. The COBRA algorithms are lightweight, with computation in 5 ms on a smartphone class microprocessor. COBRA also has low start-up latency, achieving high accuracy from a cold-start in 30 ms. The COBRA technique opens up a large number of new capabilities in communications, and electronic warfare including selective spatial jamming, geolocation and anti-geolocation.

  2. The importance of Radio Quiet Zone (RQZ) for radio astronomy

    NASA Astrophysics Data System (ADS)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin

    2013-05-01

    Most of radio observatories are located in isolated areas. Since radio sources from the universe is very weak, astronomer need to avoid radio frequency interference (RFI) from active spectrum users and radio noise produced by human made (telecommunication, mobile phone, microwave user and many more. There are many observatories around the world are surrounded by a Radio Quiet Zone (RQZ), which is it was set up using public or state laws. A Radio Quiet Zone normally consists of two areas: an exclusive area in which totally radio emissions are forbidden, with restrictions for residents and business developments, and a larger (radius up to 100 km above) coordination area where the power of radio transmission limits to threshold levels. Geographical Information System (GIS) can be used as a powerful tool in mapping large areas with varying RQZ profiles. In this paper, we report the initial testing of the usage of this system in order to identify the areas were suitable for Radio Quiet Zone. Among the important parameters used to develop the database for our GIS are population density, information on TV and telecommunication (mobile phones) transmitters, road networks (highway), and contour shielding. We will also use other information gathered from on-site RFI level measurements on selected 'best' areas generated by the GIS. The intention is to find the best site for the purpose of establishing first radio quiet zones for radio telescope in Malaysia.

  3. Accurate radio and optical positions for southern radio sources

    NASA Technical Reports Server (NTRS)

    Harvey, Bruce R.; Jauncey, David L.; White, Graeme L.; Nothnagel, Axel; Nicolson, George D.; Reynolds, John E.; Morabito, David D.; Bartel, Norbert

    1992-01-01

    Accurate radio positions with a precision of about 0.01 arcsec are reported for eight compact extragalactic radio sources south of -45-deg declination. The radio positions were determined using VLBI at 8.4 GHz on the 9589 km Tidbinbilla (Australia) to Hartebeesthoek (South Africa) baseline. The sources were selected from the Parkes Catalogue to be strong, flat-spectrum radio sources with bright optical QSO counterparts. Optical positions of the QSOs were also measured from the ESO B Sky Survey plates with respect to stars from the Perth 70 Catalogue, to an accuracy of about 0.19 arcsec rms. These radio and optical positions are as precise as any presently available in the far southern sky. A comparison of the radio and optical positions confirms the estimated optical position errors and shows that there is overall agreement at the 0.1-arcsec level between the radio and Perth 70 optical reference frames in the far south.

  4. Industrial WSN Based on IR-UWB and a Low-Latency MAC Protocol

    NASA Astrophysics Data System (ADS)

    Reinhold, Rafael; Underberg, Lisa; Wulf, Armin; Kays, Ruediger

    2016-07-01

    Wireless sensor networks for industrial communication require high reliability and low latency. As current wireless sensor networks do not entirely meet these requirements, novel system approaches need to be developed. Since ultra wideband communication systems seem to be a promising approach, this paper evaluates the performance of the IEEE 802.15.4 impulse-radio ultra-wideband physical layer and the IEEE 802.15.4 Low Latency Deterministic Network (LLDN) MAC for industrial applications. Novel approaches and system adaptions are proposed to meet the application requirements. In this regard, a synchronization approach based on circular average magnitude difference functions (CAMDF) and on a clean template (CT) is presented for the correlation receiver. An adapted MAC protocol titled aggregated low latency (ALL) MAC is proposed to significantly reduce the resulting latency. Based on the system proposals, a hardware prototype has been developed, which proves the feasibility of the system and visualizes the real-time performance of the MAC protocol.

  5. The Applications of Decision-Level Data Fusion Techniques in the Field of Multiuser Detection for DS-UWB Systems.

    PubMed

    Gu, Yebo; Yang, Minglei; Shi, Zhenguo; Wu, Zhilu

    2015-09-25

    In this paper, the decision-level data fusion techniques are extended to the multiuser detection (MUD) field. Then two novel MUD algorithms, that is the chairman arbitrating decision-level fusion criterion (CA-DFC) based MUD algorithm and the veto logic decision-level fusion criterion (VL-DFC) based MUD algorithm, are proposed for DS-UWB communication systems. In CA-DFC based method, the chairman can make his arbitration among the preliminary decisions from sub-optimal detectors by his own rule. In the VL-DFC based method, the undetermined bits in these preliminary decisions are considered to construct a simplified solution space, and then the chairman can make his final decision within this space. Simulation results demonstrate that the performances of CA-DFC and VL-DFC based MUD algorithms are superior to those of other sub-optimal MUD algorithms, and even close to that of OMD. Moreover, both of these proposed algorithms have lower computational complexity than OMD, which reveals their efficiency. Compared with CA-DFC, VL-DFC based algorithm achieves a little improvement in its performance, at the cost of the increment in its computational complexity. Thus, they can be applied to different practical situations.

  6. Adaptive modulation and intra-symbol frequency-domain averaging scheme for multiband OFDM UWB over fiber system

    NASA Astrophysics Data System (ADS)

    He, Jing; Li, Teng; Wen, Xuejie; Deng, Rui; Chen, Ming; Chen, Lin

    2016-01-01

    To overcome the unbalanced error bit distribution among subcarriers caused by inter-subcarriers mixing interference (ISMI) and frequency selective fading (FSF), an adaptive modulation scheme based on 64/16/4QAM modulation is proposed and experimentally investigated in the intensity-modulation direct-detection (IM/DD) multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) over fiber system. After 50 km standard single mode fiber (SSMF) transmission, at the bit error ratio (BER) of 1×10-3, the experimental results show that the power penalty of the IM/DD MB-OFDM UWBoF system with 64/16/4QAM adaptive modulation scheme is about 3.6 dB, compared to that with the 64QAM modulation scheme. Moreover, the receiver sensitivity has been improved about 0.52 dB when the intra-symbol frequency-domain averaging (ISFA) algorithm is employed in the IM/DD MB-OFDM UWBoF system based on the 64/16/4QAM adaptive modulation scheme. Meanwhile, after 50 km SSMF transmission, there is a negligible power penalty in the adaptively modulated IM/DD MB-OFDM UWBoF system, compared to the optical back-to-back case.

  7. On the Analysis of the Dynamics and Synchronization of Chaotic Modulation and Demodulation in UWB Communication and Positioning Systems

    NASA Astrophysics Data System (ADS)

    Chedjou, J. C.; Dada, J. P.; Moussa, I.; Takenga, C.; Anne, R.; Kyamakya, K.

    This paper studies synchronization transitions in a system of coupled non-identical self-sustained chaotic oscillators of the Rössler type. The interest devoted to the Rössler oscillators is motivated by their capability to behave chaotically at very high frequencies. Both phase synchronization and lag synchronization are analyzed in terms of a coupling parameter. It is shown that both types of synchronization can be achieved when monitoring a coupling parameter. The advantage of using one parameter to insure both types of synchronization is found in practical realizations. Indeed one should monitor only one resistor to predict the boundaries of the control resistor for the occurrence of each type of synchronization. Another advantage of monitoring only one resistor is found in the accuracy of results. An experimental study of the synchronization is carried out. Experimental waveforms in the drive and response systems are obtained. The waveforms are compared to confirm the achievement of sync hronization experimentally. One of the advantages of using analog simulation in this work is the possibility to analyze the behaviour of the coupled system at very high frequencies by performing an appropriate time scaling. This offers the possibility of using our coupled system for Ultra-wideband (UWB) applications.

  8. Virtual observatory tools and amateur radio observations supporting scientific analysis of Jupiter radio emissions

    NASA Astrophysics Data System (ADS)

    Cecconi, Baptiste; Hess, Sebastien; Le Sidaner, Pierre; Savalle, Renaud; Stéphane, Erard; Coffre, Andrée; Thétas, Emmanuel; André, Nicolas; Génot, Vincent; Thieman, Jim; Typinski, Dave; Sky, Jim; Higgins, Chuck; Imai, Masafumi

    2016-04-01

    In the frame of the preparation of the NASA/JUNO and ESA/JUICE (Jupiter Icy Moon Explorer) missions, and the development of a planetary sciences virtual observatory (VO), we are proposing a new set of tools directed to data providers as well as users, in order to ease data sharing and discovery. We will focus on ground based planetary radio observations (thus mainly Jupiter radio emissions), trying for instance to enhance the temporal coverage of jovian decametric emission. The data service we will be using is EPN-TAP, a planetary science data access protocol developed by Europlanet-VESPA (Virtual European Solar and Planetary Access). This protocol is derived from IVOA (International Virtual Observatory Alliance) standards. The Jupiter Routine Observations from the Nancay Decameter Array are already shared on the planetary science VO using this protocol, as well as data from the Iitate Low Frquency Radio Antenna, in Japan. Amateur radio data from the RadioJOVE project is also available. The attached figure shows data from those three providers. We will first introduce the VO tools and concepts of interest for the planetary radioastronomy community. We will then present the various data formats now used for such data services, as well as their associated metadata. We will finally show various prototypical tools that make use of this shared datasets.

  9. Radio emissions from RHESSI TGFs

    NASA Astrophysics Data System (ADS)

    Mezentsev, Andrey; Østgaard, Nikolai; Gjesteland, Thomas; Albrechtsen, Kjetil; Cummer, Steven

    2016-04-01

    The discovery of bursts of energetic photons coming out to space from the Earth's atmosphere, referred to as terrsetrial gamma-ray flashes (TGFs), has stimulated research activity investigating different aspects of the TGF generation and accompanying processes. Two models of the TGF production are nowadays competing to explain the observations of the TGFs and related phenomena. One of the models involves the feedback mechanism enhancing the production rate of the runaway electrons in the ambient electric field of a thundercloud. Another model considers runaway electrons accelerated in the strong local electric field in front of the upward propagating negative leader of the +IC. We performed a detailed analysis of RHESSI TGFs detected between August 2004 and September 2015. It was reported that the RHESSI satellite clock has a systematic error of ˜ 1.8 ms, but the exact value remained unknown, also it was unclear if this systematic clock error is changing with time or not. We compared RHESSI TGFs with the world wide lightning location network (WWLLN) database and found the distribution of the time delays between the TGF peak times and associated WWLLN detections. This distribution allowed us to find the value of the RHESSI systematic clock offset with the microsecond accuracy level. Also we found that this offset experienced two changes: in August 2005 and in October 2013, which was confirmed by two independent ways. We found that in case of double TGFs WWLLN detection corresponds to the second TGF of the pair. VLF magnetic field recordings from the Duke University also attribute radio sferics to the second TGF, exhibiting no detectable radio emission during the first TGFs of the TGF pairs. We have proposed a possible scenario that is consistent with the observations. This scenario supports the leader-based model of the TGF generation. Spectral characteristics of 77 sferics recorded by the Duke University VLF sensors and related to the RHEESI TGFs show that maximal

  10. AIDS radio triggers.

    PubMed

    Elias, A M

    1991-07-01

    In April 1991, the Ethnic Communities' Council of NSW was granted funding under the Community AIDS Prevention and Education Program through the Department of Community Services and Health, to produce a series of 6x50 second AIDS radio triggers with a 10-second tag line for further information. The triggers are designed to disseminate culturally-sensitive information about HIV/AIDS in English, Italian, Greek, Spanish, Khmer, Turkish, Macedonian, Serbo-Croatian, Arabic, Cantonese, and Vietnamese, with the goal of increasing awareness and decreasing the degree of misinformation about HIV/AIDS among people of non-English-speaking backgrounds through radio and sound. The 6 triggers cover the denial that AIDS exists in the community, beliefs that words and feelings do not protect one from catching HIV, encouraging friends to be compassionate, compassion within the family, AIDS information for a young audience, and the provision of accurate and honest information on HIV/AIDS. The triggers are slated to be completed by the end of July 1991 and will be broadcast on all possible community, ethnic, and commercial radio networks across Australia. They will be available upon request in composite form with an information kit for use by health care professionals and community workers.

  11. MULTIMOMENT RADIO TRANSIENT DETECTION

    SciTech Connect

    Spitler, L. G.; Cordes, J. M.; Chatterjee, S.; Stone, J.

    2012-04-01

    We present a multimoment technique for signal classification and apply it to the detection of fast radio transients in incoherently dedispersed data. Specifically, we define a spectral modulation index in terms of the fractional variation in intensity across a spectrum. A signal whose intensity is distributed evenly across the entire band has a lower modulation index than a spectrum whose intensity is localized in a single channel. We are interested in broadband pulses and use the modulation index to excise narrowband radio frequency interference by applying a modulation index threshold above which candidate events are removed. The technique is tested both with simulations and using data from known sources of radio pulses (RRAT J1928+15 and giant pulses from the Crab pulsar). The method is generalized to coherent dedispersion, image cubes, and astrophysical narrowband signals that are steady in time. We suggest that the modulation index, along with other statistics using higher order moments, should be incorporated into signal detection pipelines to characterize and classify signals.

  12. The Askaryan Radio Array

    NASA Astrophysics Data System (ADS)

    Hoffman, Kara D.

    2013-01-01

    Ultra high energy cosmogenic neutrinos could be most efficiently detected in dense, radio frequency (RF) transparent media via the Askaryan effect. Building on the expertise gained by RICE, ANITA and IceCube's radio extension in the use of the Askaryan effect in cold Antarctic ice, we are currently developing an antenna array known as ARA (The Askaryan Radio Array) to be installed in boreholes extending 200 m below the surface of the ice near the geographic South Pole. The unprecedented scale of ARA, which will cover a fiducial area of ~ 100 square kilometers, was chosen to ensure the detection of the flux of neutrinos suggested by the observation of a drop in high energy cosmic ray flux consistent with the GZK cutoff by HiRes and the Pierre Auger Observatory. Funding to develop the instrumentation and install the first prototypes has been granted, and the first components of ARA were installed during the austral summer of 2010-2011. Within 3 years of commencing operation, the full ARA will exceed the sensitivity of any other instrument in the 0.1-10 EeV energy range by an order of magnitude. The primary goal of the ARA array is to establish the absolute cosmogenic neutrino flux through a modest number of events. This information would frame the performance requirements needed to expand the array in the future to measure a larger number of neutrinos with greater angular precision in order to study their spectrum and origins.

  13. Exploring Systems Engineering (and the Universe) Through the RadioJOVE telescope

    NASA Astrophysics Data System (ADS)

    Aditi Raj, Anya

    2017-01-01

    Amateur projects in radio astronomy are popular methods to engage in what often seems to be an inaccessible field, and pre-made kits are becoming increasingly available to hobbyists and educators. One such kit is the RadioJOVE, which is attractive due to its simplicity, accessibility and its extensive support network and community of users. When coupled with an education in project management, building the RadioJOVE provides a perfect framework to learn about best practices in completing a project. We will primarily discuss the use of the RadioJOVE project to enhance study in project management and systems engineering. We also intend to discuss the importance of amateur projects such as the RadioJOVE in gaining a holistic understanding of radio astronomy and the project’s potential to spark interest in radio astronomy in students of various disciplines.

  14. Interstellar matter in early-type galaxies. III - Radio emission and star formation

    NASA Technical Reports Server (NTRS)

    Walsh, D. E. P.; Knapp, G. R.; Wrobel, J. M.; Kim, D.-W.

    1989-01-01

    The relationship between the IR and radio luminosity in early-type galaxies is examined using the correlation among spiral galaxies as a diagnostic of the presence of star formation. For ellipticals, the presence of long-wavelength IR emission enhances the probability that the galaxy is a radio source and is also correlated with the strength of that source. These findings are consistent with the idea that active radio nuclei are due to black holes being fueled by accretion of gas. The majority of S0s detected in both radio and far-IR have a similar ratio of IR to radio luminosity as has been found in spirals, and which is considered to be indicative of recent star formation. Sensitive radio limits for several galaxies reveal another substantial population of S0s with moderately strong IR emission unaccompanied by radio power.

  15. Obstacle avoidance and concealed target detection using the Army Research Lab ultra-wideband synchronous impulse reconstruction (UWB SIRE) forward imaging radar

    NASA Astrophysics Data System (ADS)

    Nguyen, Lam; Wong, David; Ressler, Marc; Koenig, Francois; Stanton, Brian; Smith, Gregory; Sichina, Jeffrey; Kappra, Karl

    2007-04-01

    The U.S. Army Research Laboratory (ARL), as part of a mission and customer funded exploratory program, has developed a new low-frequency, ultra-wideband (UWB) synthetic aperture radar (SAR) for forward imaging to support the Army's vision of an autonomous navigation system for robotic ground vehicles. These unmanned vehicles, equipped with an array of imaging sensors, will be tasked to help detect man-made obstacles such as concealed targets, enemy minefields, and booby traps, as well as other natural obstacles such as ditches, and bodies of water. The ability of UWB radar technology to help detect concealed objects has been documented in the past and could provide an important obstacle avoidance capability for autonomous navigation systems, which would improve the speed and maneuverability of these vehicles and consequently increase the survivability of the U. S. forces on the battlefield. One of the primary features of the radar is the ability to collect and process data at combat pace in an affordable, compact, and lightweight package. To achieve this, the radar is based on the synchronous impulse reconstruction (SIRE) technique where several relatively slow and inexpensive analog-to-digital (A/D) converters are used to sample the wide bandwidth of the radar signals. We conducted an experiment this winter at Aberdeen Proving Ground (APG) to support the phenomenological studies of the backscatter from positive and negative obstacles for autonomous robotic vehicle navigation, as well as the detection of concealed targets of interest to the Army. In this paper, we briefly describe the UWB SIRE radar and the test setup in the experiment. We will also describe the signal processing and the forward imaging techniques used in the experiment. Finally, we will present imagery of man-made obstacles such as barriers, concertina wires, and mines.

  16. Workshop on Radio Transients

    NASA Astrophysics Data System (ADS)

    Croft, Steve; Gaensler, Bryan

    2012-04-01

    abstract-type="normal">SummaryWe are entering a new era in the study of variable and transient radio sources. This workshop discussed the instruments and the strategies employed to study those sources, how they are identified and classified, how results from different surveys can be compared, and how radio observations tie in with those at other wavelengths. The emphasis was on learning what common ground there is between the plethora of on-going projects, how methods and code can be shared, and how best practices regarding survey strategy could be adopted. The workshop featured the four topics below. Each topic commenced with a fairly brief introductory talk, which then developed into discussion. By way of preparation, participants had been invited to upload and discuss one slide per topic to a wiki ahead of the workshop. 1. Telescopes, instrumentation and survey strategy. New radio facilities and on-going projects (including upgrades) are both studying the variability of the radio sky, and searching for transients. The discussion first centred on the status of those facilities, and on projects with a time-domain focus, both ongoing and planned, before turning to factors driving choices of instrumentation, such as phased array versus single pixel feeds, the field of view, spatial and time resolution, frequency and bandwidth, depth, area, and cadence of the surveys. 2. Detection, pipelines, and classification. The workshop debated (a) the factors that influence decisions to study variability in the (u,v) plane, in images, or in catalogues, (b) whether, and how much, pipeline code could potentially be shared between one project and another, and which software packages are best for different approaches, (c) how data are stored and later accessed, and (d) how transients and variables are defined and classified. 3. Statistics, interpretation, and synthesis. It then discussed how (i) the choice of facility and strategy and (ii) detection and classification schemes

  17. Radio quiet, please! - protecting radio astronomy from interference

    NASA Astrophysics Data System (ADS)

    van Driel, W.

    2011-06-01

    The radio spectrum is a finite and increasingly precious resource for astronomical research, as well as for other spectrum users. Keeping the frequency bands used for radio astronomy as free as possible of unwanted Radio Frequency Interference (RFI) is crucial. The aim of spectrum management, one of the tools used towards achieving this goal, includes setting regulatory limits on RFI levels emitted by other spectrum users into the radio astronomy frequency bands. This involves discussions with regulatory bodies and other spectrum users at several levels - national, regional and worldwide. The global framework for spectrum management is set by the Radio Regulations of the International Telecommunication Union, which has defined that interference is detrimental to radio astronomy if it increases the uncertainty of a measurement by 10%. The Radio Regulations are revised every three to four years, a process in which four organisations representing the interests of the radio astronomical community in matters of spectrum management (IUCAF, CORF, CRAF and RAFCAP) participate actively. The current interests and activities of these four organisations range from preserving what has been achieved through regulatory measures, to looking far into the future of high frequency use and giant radio telescope use.

  18. Updates to the NASA Space Telecommunications Radio System (STRS) Architecture

    NASA Technical Reports Server (NTRS)

    Kacpura, Thomas J.; Handler, Louis M.; Briones, Janette; Hall, Charles S.

    2008-01-01

    This paper describes an update of the Space Telecommunications Radio System (STRS) open architecture for NASA space based radios. The STRS architecture has been defined as a framework for the design, development, operation and upgrade of space based software defined radios, where processing resources are constrained. The architecture has been updated based upon reviews by NASA missions, radio providers, and component vendors. The STRS Standard prescribes the architectural relationship between the software elements used in software execution and defines the Application Programmer Interface (API) between the operating environment and the waveform application. Modeling tools have been adopted to present the architecture. The paper will present a description of the updated API, configuration files, and constraints. Minimum compliance is discussed for early implementations. The paper then closes with a summary of the changes made and discussion of the relevant alignment with the Object Management Group (OMG) SWRadio specification, and enhancements to the specialized signal processing abstraction.

  19. Radio emision from supernova remnants

    NASA Astrophysics Data System (ADS)

    Dubner, G.

    2016-06-01

    The vast majority of supernova remnants (SNRs) in our Galaxy and nearby galaxies have been discovered through radio observations, and only a very small number of the SNRs catalogued in the Milky Way have not been detected in the radio band, or are poorly defined by current radio observations. The study of the radio emission from SNRs is an excellent tool to investigate morphological characteristics, marking the location of shock fronts and contact discontinuities; the presence, orientation and intensity of the magnetic field; the energy spectrum of the emitting particles; and the dynamical consequences of the interaction with the circumstellar and interstellar medium. I will review the present knowledge of different important aspects of radio remnants and their impact on the interstellar gas. Also, new radio studies of the Crab Nebula carried out with the Karl Jansky Very Large Array (JVLA) at 3 GHz and with ALMA at 100 GHz, will be presented.

  20. Uzaybimer Radio Telescope Control System

    NASA Astrophysics Data System (ADS)

    Balbay, R.; Öz, G. K.; Arslan, Ö.; Özeren, F. F.; Küçük, İ.

    2016-12-01

    A 13 meters former NATO radar is being converted into a radio telescope. The radio telescope is controlled by a system which has been developed at UZAYBİMER. The Telescope Control System(TCS) has been designed using modern industrial systems. TCS has been developed in LabView platform in which works Windows embedded OS. The position feedback used on radio telescopes is an industrial EtherCAT standard. ASCOM library is used for astronomical calculations.

  1. Radio Emission from Binary Stars

    NASA Astrophysics Data System (ADS)

    Hjellming, R.; Murdin, P.

    2000-11-01

    Stellar radio emission is most common in double star systems where each star provides something essential in producing the large amounts of radio radiation needed for it to be detectable by RADIO TELESCOPES. They transfer mass, supply energy or, when one of the stars is a NEUTRON STAR or BLACK HOLE, have the strong gravitational fields needed for the energetic particles and magnetic fields needed...

  2. The properties of radio ellipticals

    NASA Astrophysics Data System (ADS)

    Sparks, W. B.; Disney, M. J.; Wall, J. V.; Rodgers, A. W.

    1984-03-01

    The authors present optical and additional radio data for the bright galaxies of the Disney & Wall survey. These data form the basis of a statistical comparison of the properties of radio elliptical galaxies to radio-quiet ellipticals. The correlations may be explained by the depth of the gravitational potential well in which the galaxy resides governing the circumstances under which an elliptical galaxy rids itself of internally produced gas.

  3. Radio-loud and Radio-quiet QSOs

    NASA Astrophysics Data System (ADS)

    Kellermann, K. I.; Condon, J. J.; Kimball, A. E.; Perley, R. A.; Ivezić, Željko

    2016-11-01

    We discuss 6 GHz JVLA observations covering a volume-limited sample of 178 low-redshift (0.2< z< 0.3) optically selected quasi-stellar objects (QSOs). Our 176 radio detections fall into two clear categories: (1) about 20% are radio-loud QSOs (RLQs) with spectral luminosities of {L}6≳ {10}23.2 {{W}} {{Hz}}-1 that are primarily generated in the active galactic nucleus (AGN) responsible for the excess optical luminosity that defines a bona fide QSO; and (2) the remaining 80% that are radio-quiet QSOs (RQQs) that have {10}21≲ {L}6≲ {10}23.2 {{W}} {{Hz}}-1 and radio sizes ≲ 10 {kpc}, and we suggest that the bulk of their radio emission is powered by star formation in their host galaxies. “Radio-silent” QSOs ({L}6≲ {10}21 {{W}} {{Hz}}-1) are rare, so most RQQ host galaxies form stars faster than the Milky Way; they are not “red and dead” ellipticals. Earlier radio observations did not have the luminosity sensitivity of {L}6≲ {10}21 {{W}} {{Hz}}-1 that is needed to distinguish between such RLQs and RQQs. Strong, generally double-sided radio emission spanning \\gg 10 {kpc} was found to be associated with 13 of the 18 RLQ cores with peak flux densities of {S}{{p}}> 5 {mJy} {{beam}}-1 ({log}(L)≳ 24). The radio luminosity function of optically selected QSOs and the extended radio emission associated with RLQs are both inconsistent with simple “unified” models that invoke relativistic beaming from randomly oriented QSOs to explain the difference between RLQs and RQQs. Some intrinsic property of the AGNs or their host galaxies must also determine whether or not a QSO appears radio-loud.

  4. RADIO FREQUENCY ATTENUATOR

    DOEpatents

    Giordano, S.

    1963-11-12

    A high peak power level r-f attenuator that is readily and easily insertable along a coaxial cable having an inner conductor and an outer annular conductor without breaking the ends thereof is presented. Spaced first and second flares in the outer conductor face each other with a slidable cylindrical outer conductor portion therebetween. Dielectric means, such as water, contact the cable between the flares to attenuate the radio-frequency energy received thereby. The cylindrical outer conductor portion is slidable to adjust the voltage standing wave ratio to a low level, and one of the flares is slidable to adjust the attenuation level. An integral dielectric container is also provided. (AFC)

  5. Packet Radio Communications Project

    DTIC Science & Technology

    1974-12-01

    init.ate any pending DMA channel I/O now possible as a result of the completed DMA I/O operation. For example, if the packet transmision has been...keyboard and printer b. Binary data record I/O fo/from the tape media c. Scan for unsolicited keyboard input 2-12 Software description of experimental...the station and transmit to the station packets input on the radio receivers. The goal is to provide a transparent packet transfer media to

  6. Radio frequency strain monitor

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S. (Inventor); Rogowski, Robert S. (Inventor); Holben, Jr., Milford S. (Inventor)

    1989-01-01

    A radio frequency strain monitor includes a voltage controlled oscillator for generating an oscillating signal that is input into a propagation path. The propagation path is preferably bonded to the surface of a structure to be monitored and produces a propagated signal. A phase difference between the oscillating and propagated signals is detected and maintained at a substantially constant value which is preferably a multiple of 90.degree. by changing the frequency of the oscillating signal. Any change in frequency of the oscillating signal provides an indication of strain in the structure to which the propagation path is bonded.

  7. Lunar Farside Radio Lab

    NASA Astrophysics Data System (ADS)

    Maccone, Claudio

    2005-03-01

    It is proposed that the Farside of the Moon should be protected legally against man-made radio pollution and uncontrolled exploitation. In fact, only by establishing a radiotelescope on the Farside of the Moon it will finally be possible to cope with the Radio Frequency Interference (RFI) that is now increasingly plaguing all of Radioastronomy, Bioastronomy and Search for Extraterrestrial Intelligence (SETI) Searches done from the surface of the Earth. It is suggested to partition the Farside into 3 sectors, each 60°wide, to ensurethe creation of a future “Lunar Farside Radio Lab” inside crater Daedalus (at 180°E) with our planned Radiotelescope (in practice a Phased Array),complete freedom to exploit the Nearside as well as the four Lagrangian points L1, L3, L4 and L5 of the Earth Moon system by allowing even some International Space Stations to be located there. It is also claimed, however, thatthe “opposite” Lagrangian point L2 should possibly be kept free of spacecrafts that would flood the Farside by the RFI they produce. Realistically, it might be difficult to comply with the latter request in view of the far-future development of a Space Base located there in order to depart towards the Asteroids and the Outer Planets at very reduced fuel consumption. A more reasonable request about any future space station located at the Earth Moon L2 point is thus that this future space station should be shielded to prevent its RFI from reaching the Farside of the Moon.A number of further astrophysical, astronautical and technical issues could just be highlighted in this study and deserve much more elaboration. To mention a few:the precise size of the “Quiet Cone” extending into space above the Farside of the Moon. Also, the experimental measurement of how quiet this Cone actually is by letting a radiometer orbit the Moon (see the web site www.rli.it);the mathematical modelling of the weak ionosphere of the Moon and its possible diffraction effects at very

  8. Solar radio emission

    NASA Technical Reports Server (NTRS)

    Goldman, M. V.; Smith, D. F.

    1981-01-01

    Active areas of both observational and theoretical research in which rapid progress is being made are discussed. These include: (1) the dynamic spectrum or frequency versus time plot; (2) physical mechanisms in the development of various types of bursts; (3) microwave type 1, 2, 3, and moving type 4 bursts; (4) bursts caused by trapped electrons; (5) physics of type 3bursts; (6) the physics of type 2 bursts and their related shocks; (7) the physics of both stationary and moving traps and associated type 1 and moving type 4 bursts; and (8) the status of the field of solar radio emission.

  9. Observations of Solar Radio Transients

    NASA Astrophysics Data System (ADS)

    Paige, Giorla

    2011-05-01

    A low frequency radio telescope has been recently been constructed on the campus of the The College of New Jersey (TCNJ) and has begun conducting observations at 20MHz as part of NASA'a Radio Jove program. This instrument is capable of observations of solar radio emission including strong prompt radio emission associated with solar burst events. We will discuss solar observations conducted with this instrument as well as an effort to conduct coincident observations with the Eight-meter-wavelength Transient Array (ETA) and the Long Wavelength Array (LWA).

  10. Internet Resources for Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Andernach, H.

    A subjective overview of Internet resources for radio-astronomical information is presented. Basic observing techniques and their implications for the interpretation of publicly available radio data are described, followed by a discussion of existing radio surveys, their level of optical identification, and nomenclature of radio sources. Various collections of source catalogues and databases for integrated radio source parameters are reviewed and compared, as well as the web interfaces to interrogate the current and ongoing large-area surveys. Links to radio observatories with archives of raw (uv-) data are presented, as well as services providing images, both of individual objects or extracts (``cutouts'') from large-scale surveys. While the emphasis is on radio continuum data, a brief list of sites providing spectral line data, and atomic or molecular information is included. The major radio telescopes and surveys under construction or planning are outlined. A summary is given of a search for previously unknown optically bright radio sources, as performed by the students as an exercise, using Internet resources only. Over 200 different links are mentioned and were verified, but despite the attempt to make this report up-to-date, it can only provide a snapshot of the situation as of mid-1998.

  11. Optical emission in the radio lobes of radio galaxies. II - New observations of 21 radio lobes

    NASA Astrophysics Data System (ADS)

    Crane, P.; Tyson, J. A.; Saslaw, W. C.

    1983-02-01

    The authors report new identifications of optical emission associated with the radio lobes of double radio galaxies. Optical emission is present in the outer radio structure of the sources 3C 219, 3C 244.1, 3C 247, 3C 252, 3C 268.2, 3C 321, 3C 319, 3C 337, and possibly in 3C 330. The authors have not found emission to the detection limit of V ≡ 24 in the sources 3C 79, 3C 173.1, 3C 223, 3C 325, and 3C 381. Of the 21 separate sources in optical studies of extended lobes of radio galaxies reported to date, 16 radio sources observed so far show significant optical emission within one or both lobes, while in 11 of these the optical object is within 2arcsec of the radio peak.

  12. The Extragalactic Radio Background

    NASA Technical Reports Server (NTRS)

    Kogut, A.; Fixsen, D. J.; Levin, S. M.; Limon, M.; Lubin, P. M.; Seiffert, M.; Singal, J.; Villela, T.; Wollack, E.; Wuensche, C. A.

    2011-01-01

    The existence of an isotropic component of the high-latitude radio sky has been recognized for nearly fifty years, but has typically been assumed to be Galactic in origin. We use recent radio observations to test whether the observed high-latitude component could originate within either an extended Galactic halo or a more local "bubble" structure. The lack of significant polarization from the isotropic component, combined with the lack of significant correlation with the Galactic far-infrared emission, rule out an origin within the Galaxy. We conclude that an extragalactic origin is the only viable alternative for the bulk of the isotropic high-latitude emission. The extragalactic component is 2-3 times brighter than local (Galactic) emission towards the Galactic poles and is consistent with a power law in frequency with amplitude T(sub r) = 24.1 plus or minus 2.1 K and spectral index beta = -2.599 plus or minus 0.036 evaluated at reference frequency 310 MHz.

  13. [Development of innovative methods of electromagnetic field evaluation for portable radio-station].

    PubMed

    Rubtsova, N B; Perov, S Iu; Bogacheva, E V; Kuster, N

    2013-01-01

    The results of portable radio-station "Radiy-301" electromagnetic fields (EMF) emission measurement and specific absorption rate data evaluation has shown that workers' exposure EMF levels may elevate hygienic norms and hereupon can be health risk factor. Possible way of portable radio-station EMF dosimetry enhancement by means of domestic and international approaches harmonization is considered.

  14. Space Telecommunications Radio Architecture (STRS)

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.

    2006-01-01

    A software defined radio (SDR) architecture used in space-based platforms proposes to standardize certain aspects of radio development such as interface definitions, functional control and execution, and application software and firmware development. NASA has charted a team to develop an open software defined radio hardware and software architecture to support NASA missions and determine the viability of an Agency-wide Standard. A draft concept of the proposed standard has been released and discussed among organizations in the SDR community. Appropriate leveraging of the JTRS SCA, OMG's SWRadio Architecture and other aspects are considered. A standard radio architecture offers potential value by employing common waveform software instantiation, operation, testing and software maintenance. While software defined radios offer greater flexibility, they also poses challenges to the radio development for the space environment in terms of size, mass and power consumption and available technology. An SDR architecture for space must recognize and address the constraints of space flight hardware, and systems along with flight heritage and culture. NASA is actively participating in the development of technology and standards related to software defined radios. As NASA considers a standard radio architecture for space communications, input and coordination from government agencies, the industry, academia, and standards bodies is key to a successful architecture. The unique aspects of space require thorough investigation of relevant terrestrial technologies properly adapted to space. The talk will describe NASA s current effort to investigate SDR applications to space missions and a brief overview of a candidate architecture under consideration for space based platforms.

  15. Safety and Special Radio Services.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    Numerous radio stations across the nation perform nonbroadcast services in areas ranging from aviation, forestry protection, and telephone maintenance to amateur and citizen radio. These services can be grouped in four general categories: (1) safety, (2) industry, (3) land transportation, and (4) miscellaneous purposes. This bulletin briefly…

  16. Frequency Allocation; The Radio Spectrum.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    The Federal Communications Commission (FCC) assigns segments of the radio spectrum to categories of users, and specific frequencies within each segment to individual users. Since demand for channel space exceeds supply, the process is complex. The radio spectrum can be compared to a long ruler: the portion from 10-540 kiloHertz has been set aside…

  17. Stabilized radio-frequency quadrupole

    DOEpatents

    Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

    1982-09-29

    A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

  18. The future for radio astronomy

    NASA Astrophysics Data System (ADS)

    Breton, Rene P.; Hassall, Tom

    2013-12-01

    THE TRANSIENT UNIVERSE Rene P Breton and Tom Hassall argue that, while radio astronomy has always involved transient phenomena, exploration of this part of the electromagnetic spectrum has been falling behind because of the lack of data. But the advent of a new generation of radio telescopes such as LOFAR, could change that.

  19. Audiences for Contemporary Radio Formats.

    ERIC Educational Resources Information Center

    Lull, James T.; And Others

    A radio audience survey of 110 sample geographic clusters in the Santa Barbara, California, area served a twofold purpose: the construction of a demographic profile of audience types according to radio format choices, and the identification and analysis of various audience subgroups. A skip interval technique of these geographic clusters resulted…

  20. The Radio Phenomenon in Italy.

    ERIC Educational Resources Information Center

    Faenza, Roberto

    One in a series of studies of experiments in new audiovisual techniques in Europe and the situations in some member countries, this paper traces the development of radio in Italy. Opposing views about radio broadcasting (public monopoly vs. freedom of broadcasting) are examined, and the various political and legal aspects of communications in…

  1. 78 FR 32165 - Commercial Radio Operators; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... COMMISSION 47 CFR Part 0 Commercial Radio Operators; Correction AGENCY: Federal Communication Commission... rules concerning radio operator licenses for maritime and aviation in order to reduce administrative...) Administers the Commission's commercial radio operator program (part 13 of this chapter); the...

  2. Galaxy clusters: Radio relics from fossil electrons

    NASA Astrophysics Data System (ADS)

    Johnston-Hollitt, Melanie

    2017-01-01

    The detection of a tailed radio galaxy in a galaxy cluster conjoined to a region of diffuse radio emission confirms that radio galaxies provide the energetic electrons needed to explain the origin of this enigmatic emission.

  3. Report on ''European Radio Interferometry School 2015''

    NASA Astrophysics Data System (ADS)

    Laing, R.; Richards, A.

    2016-03-01

    The sixth European Interferometry School (ERIS2015) was held at ESO for the first time. As usual the school was aimed at graduate students and early-career postdocs, but this year the emphasis was on enhanced wide-bandwidth interferometers covering metre to submillimetre wavebands. More than 100 participants attended ERIS2015. The topics of the school are briefly described here. They covered a wide range, from an introduction to radio interferometric techniques through packages for data reduction and analysis to hands-on workshop sessions and proposal writing.

  4. Radio characteristics of galactic nuclei

    NASA Astrophysics Data System (ADS)

    Condon, J. J.

    1986-02-01

    Radio characteristics of galactic nuclei, providing such unique information as spectral data on source variability, and the long-term history of the central engine and its duration of activity and total energy, are reviewed. The compact radio source characteristics are complicated by orientation-dependent relativistic beaming and by refractive focusing in the interstellar medium. Incoherent synchrotron radiation is thought to be the emission mechanism, with the result that synchrotron self-absorption in compact sources hides the central engine from direct radio observation. However, the history revealed by the extended jets and lobes of radio galaxies and quasars favors a single massive object not supported by radiation pressure, either a spinar or a black hole, as the energy source in radio-galaxy nuclei.

  5. Radio outburst of BL Lacertae

    NASA Astrophysics Data System (ADS)

    Buemi, C. S.; Leto, P.; Trigilio, C.; Umana, G.; Giroletti, M.; Orienti, M.; Raiteri, C. M.; Villata, M.; Bach, U.

    2013-04-01

    We report on extremely high radio flux of BL Lacertae at 43 and 8 GHz. Observations at 43 GHz with the 32 m radio telescope in Noto (Italy) revealed a flux density of 10.5 +/- 0.2 Jy on 2013 April 10.65, while observations at 8 GHz with the 32 m radio telescope in Medicina (Italy) detected a flux density of 8.2 +/- 0.7 Jy on April 12.22. These extremely high radio fluxes show that the radio activity likely correlated to the strong optical, near-infrared, and gamma-ray activity of 2011-2012 (see ATels #4028, #4031, #4155, #4271, #4277, #4349, #4565, #4600), and X-ray activity of late 2012 (ATels #4557, #4627), is far to be exhausted.

  6. Exploring the Dynamic Radio Sky

    NASA Astrophysics Data System (ADS)

    Mooley, Kunal P.; Hallinan, Gregg; Frail, Dale A.; Myers, Steven T.; Kulkarni, Shrinivas R.; Bourke, Stephen; Horesh, Assaf

    2015-01-01

    Most of what is currently known about slow radio transients (supernovae, gamma-ray bursts, tidal disruption events, stellar flares, etc.) has come via radio follow-up of objects identified by synoptic telescopes at optical, X-ray or gamma-ray wavelengths. However, with the ability to capture obscured, unbeamed and magnetically-driven phenomena, radio surveys offer unique discovery strong diagnostic for cosmic transients. For the first time, we are systematically exploring the dynamic radio sky on timescales between one day to several years using multi-epoch large surveys with the Karl G. Jansky Array (VLA). We have carried out surveys in the COSMOS deep field as well as wide fields like Stripe 82. I have developed a unique infrastructure for near-real-time calibration, imaging, transient search, transient vetting, rapid multiwavelength follow-up, and contemporaneous optical surveys to better characterize radio transient phenomena. A large part of my thesis includes the commissioning of a new observing mode at the VLA: On-The-Fly Mosaicking. This mode has significantly improved the survey efficiency of the VLA, and it is a driver for VLASS, the future all-sky survey planned with this telescope. Through our radio surveys we have discovered several fascinating transients that are unique to the radio. These surveys have established the VLA as an efficient transient discovery machine. My thesis has enormous implications for how to design efficient transient surveys for the next generation of radio interferometer facilities like ASKAP, MeerKAT, WSRT/Apertif and LOFAR. My work has also provided answers to key problems such as the rates of transients, demographics of variability of radio sources including AGN, and false-positive foreground for future searches for the radio counterparts of gravitational-wave (GW) sources.

  7. The Radio Language Arts Project: adapting the radio mathematics model.

    PubMed

    Christensen, P R

    1985-01-01

    Kenya's Radio Language Arts Project, directed by the Academy for Educational Development in cooperation with the Kenya Institute of Education in 1980-85, sought to teach English to rural school children in grades 1-3 through use of an intensive, radio-based instructional system. Daily 1/2 hour lessons are broadcast throughout the school year and supported by teachers and print materials. The project further was aimed at testing the feasibility of adaptation of the successful Nicaraguan Radio Math Project to a new subject area. Difficulties were encountered in articulating a language curriculum with the precision required for a media-based instructional system. Also a challenge was defining the acceptable regional standard for pronunciation and grammar; British English was finally selected. An important modification of the Radio Math model concerned the role of the teacher. While Radio Math sought to reduce the teacher's responsibilities during the broadcast, Radio Language Arts teachers played an important instructional role during the English lesson broadcasts by providing translation and checks on work. Evaluations of the Radio language Arts Project suggest significant gains in speaking, listening, and reading skills as well as high levels of satisfaction on the part of parents and teachers.

  8. Radio Seeing Monitor Interferometer

    NASA Astrophysics Data System (ADS)

    Hiriart, David; Valdez, Jorge; Zaca, Placido; Medina, José L.

    2002-10-01

    A two-element interferometer for monitoring atmospheric phase fluctuations (radio seeing) is presented; this uses the unmodulated beacon signal at 11.715 GHz from a geostationary satellite. The system measures phase differences on the signal received by two small antennas separated by 50 m. The system incorporates the best features from previous designs: a heterodyne phase-lock receiver and an IQ demodulator system. Phase fluctuations measured at this frequency may be extrapolated to millimetric and submillimetric wavelengths since the atmosphere is not dispersive at these frequencies. The instrument has been tested at the Observatory San Pedro Martir (Mexico) at 2800 m above sea level. The final destination of the instrument is Cerro la Negra (Mexico), where the Large Millimeter Telescope is under construction, at an altitude of 4600 m.

  9. Radio pulsar disk electrodynamics

    NASA Technical Reports Server (NTRS)

    Michel, F. C.

    1983-01-01

    Macroscopic physics are discussed for the case of a disk close to an isolated, magnetized, rotating neutron star that acts as a Faraday disk dynamo, while the disk acts as both a load and a neutral sheet. This sheet allows the polar cap current to return to the neutron star, splitting a dipolar field into two monopolar halves. The dominant energy loss is from the stellar wind torque, and the next contribution is dissipation in the auroral zones, where the current returns to the star in a 5 cm-thick sheet. The disk itself may be a source of visible radiation comparable to that in pulsed radio frequency emission. As the pulsar ages, the disk expands and narrows into a ring which, it is suggested, may lead to a cessation of pulsed emission at periods of a few sec.

  10. The Physics of Cooling Flow Clusters with Central Radio Sources

    NASA Technical Reports Server (NTRS)

    Sarazin, Craig L.

    2005-01-01

    Central galaxies in rich clusters are the sites of cluster cooling flows, with large masses of gas cooling through part of the X-ray band. Many of these galaxies host powerful radio sources. These sources can displace and compress the X-ray gas leading to enhanced cooling and star formation. We observed the bright cooling flow Abell 2626 with a strangely distorted central radio source. We wished to understand the interaction of radio and X-ray thermal plasma, and to determine the dynamical nature of this cluster. One aim was to constrain the source of additional pressure in radio "holes" in the X-ray emission needed to support overlying shells of X-ray gas. We also aimed to study the problem of the lack of kT < 1-2 keV gas in cooling flows by searching for abundance inhomogeneities, heating from the radio source, and excess absorption. We also have a Chandra observation of this cluster. There were problems with the pipeline processing of this data due to a telemetry dropout. We are publishing the Chandra and XMM data together. Delays with the Chandra data have slowed up the publication. At the center of the cluster, there is a complex interaction of the odd, Z-shaped radio source, and the X-ray plasma. However, there are no clear radio bubbles. Also, the cluster SO galaxy IC 5337, which is projected 1.5 arcmin west of the cluster center, has unusual tail-like structures in both the radio and X-ray. It appears to be falling into the cluster center. There is a hot, probably shocked region of gas to the southwest, which is apparently due to the merger of a subcluster in this part of the system. There is also a merging subcluster to the northeast. The axes of these two mergers agrees with a supercluster filament structure.

  11. Radio Astronomy Explorer /RAE/. I - Observations of terrestrial radio noise.

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Caruso, J. A.; Stone, R. G.

    1973-01-01

    Radio Astronomy Explorer (RAE) I data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial radio noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 dB and more above cosmic noise background, on frequencies above the F-layer critical frequency.

  12. Radio studies of extragalactic supernovae.

    PubMed

    Weiler, K W; Sramek, R A; Panagia, N

    1986-03-14

    Some exploding stars (supernovae) are powerful emitters of centimeter radio radiation. Detailed observations have shown that these supernovae quickly become detectable in the radio range, first at shorter wavelengths (higher frequencies) and later at progressively longer and longer wavelengths (lower frequencies). This part of the phenomenon appears to be well explained by a monotonic decrease in the amount of ionized material surrounding the radio-emitting regions as the shock from the explosion travels outward. The radio emission itself is of a nonthermal, synchrotron origin, as is the case in most bright cosmic radio sources. Once the absorption effects become negligible, the radio intensity declines with time until reaching the detection limit of the telescope. Models suggest that the absorbing material originates in a dense wind of matter lost by the supernova progenitor star, or by its companion if it is in a binary system, in the last stages of evolution before the explosion. The synchrotron radio emission can be generated either externally by the shock wave from the explosion propagating through this same high density stellar wind or internally by a rapidly rotating neutron star, which is the collapsed core of the exploded star. Present results appear to favor the former model for at least the first several years after the supernova explosion, although the latter model remains viable.

  13. Analysis of hyperbolic signatures from small discontinuities using an UWB ground-coupled radar: FDTD simulations and field experiments

    NASA Astrophysics Data System (ADS)

    Sagnard, Florence; Tebchrany, Elias; Baltazart, Vincent

    2013-04-01

    Ground penetrating radar (GPR) is a well-known non-destructive technique based on electromagnetic wave propagation that is able to detect by reflection or scattering of waves dielectric discontinuities in the underground. Our application is mainly concerned with civil engineering to perform supervision, inventory, and soil characterization. Because the air-coupled radar suffers from a significant reflection at the ground interface that reduces energy transfer of electromagnetic radiation in the sub-surface and penetration depth, we have developed an ultra-wide band (UWB) ground-coupled radar made of a pair of partially shielded compact planar bowtie slot antennas. As the antenna dimension (36*23 cm2) is close to the A4 sheet size, the maturity of the microstrip technology has allowed to design a particular geometry on the FR4 substrate (h=1.5 mm) which is able to operate at frequencies from 460 MHz to beyond 4 GHz in air. Contrary to a commercial GPR where details on antenna design are not available, it appears here possible to know and control the radiation characteristics and develop full-wave FDTD modeling that can represent field experiments for comparisons and analyses. The objective of this work is to improve, by means of a parametric study, the knowledge of physical phenomena involved in dielectric polarization when waves interact with buried discontinuities and particularly cracks, pipes, delaminations that can be distinguished by their shape, size, dielectric contrast with the surrounding medium, orientation relative to the electric field… Thus, we have first characterized by FDTD modeling and field measurements in a wet sand the radar link in two perpendicular polarizations (parallel and mirror) in the presence of a common soil (epsilon'=5.5, sigma=0.01 S/m) considering variable offsets. Afterwards, we have studied and analyzed the hyperbola signatures generated by the presence of buried canonical objects (pipes, strips) with several dielectric

  14. Radio emission in Mercury magnetosphere

    NASA Astrophysics Data System (ADS)

    Varela, J.; Reville, V.; Brun, A. S.; Pantellini, F.; Zarka, P.

    2016-10-01

    Context. Active stars possess magnetized wind that has a direct impact on planets that can lead to radio emission. Mercury is a good test case to study the effect of the solar wind and interplanetary magnetic field (IMF) on radio emission driven in the planet magnetosphere. Such studies could be used as proxies to characterize the magnetic field topology and intensity of exoplanets. Aims: The aim of this study is to quantify the radio emission in the Hermean magnetosphere. Methods: We use the magnetohydrodynamic code PLUTO in spherical coordinates with an axisymmetric multipolar expansion for the Hermean magnetic field, to analyze the effect of the IMF orientation and intensity, as well as the hydrodynamic parameters of the solar wind (velocity, density and temperature), on the net power dissipated on the Hermean day and night side. We apply the formalism derived by Zarka et al. (2001, Astrophys. Space Sci., 277, 293), Zarka (2007, Planet. Space Sci., 55, 598) to infer the radio emission level from the net dissipated power. We perform a set of simulations with different hydrodynamic parameters of the solar wind, IMF orientations and intensities, that allow us to calculate the dissipated power distribution and infer the existence of radio emission hot spots on the planet day side, and to calculate the integrated radio emission of the Hermean magnetosphere. Results: The obtained radio emission distribution of dissipated power is determined by the IMF orientation (associated with the reconnection regions in the magnetosphere), although the radio emission strength is dependent on the IMF intensity and solar wind hydro parameters. The calculated total radio emission level is in agreement with the one estimated in Zarka et al. (2001, Astrophys. Space Sci., 277, 293) , between 5 × 105 and 2 × 106 W.

  15. Software-defined radio with flexible RF front end for satellite maritime radio applications

    NASA Astrophysics Data System (ADS)

    Budroweit, Jan

    2016-09-01

    This paper presents the concept of a software-defined radio with a flexible RF front end. The design and architecture of this system, as well as possible application examples will be explained. One specific scenario is the operation in maritime frequency bands. A well-known service is the Automatic Identification System (AIS), which has been captured by the DLR mission AISat, and will be chosen as a maritime application example. The results of an embedded solution for AIS on the SDR platform are presented in this paper. Since there is an increasing request for more performance on maritime radio bands, services like AIS will be enhanced by the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). The new VHF Data Exchange Service (VDES) shall implement a dedicated satellite link. This paper describes that the SDR with a flexible RF front end can be used as a technology demonstration platform for this upcoming data exchange service.

  16. Radio protection zone evaluation at the Dominion Radio Astrophysical Observatory

    NASA Astrophysics Data System (ADS)

    Tapping, Ken

    Increasing use of the radio spectrum by licensed and unlicensed devices, together with the encroachment of housing developments are an issue facing many radio observatories, including the Dominion Radio Astrophysical Observatory (DRAO), located near Penticton in Southern British Columbia. A joint study by Industry Canada (Canada's national spectrum manager), and the National Research Council (Operator of DRAO) is currently in progress to examine protection zone needs and the reliability of the definitions of the zone, and the general level of background noise from growing local communities. The objectives are to produce a definition of a protection zone that is useful in spectrum management to protect the observatory, and to establish how much local community development is acceptable if the observatory is to remain a viable location for radio astronomical observations. This presentation will summarize the results so far in this ongoing study.

  17. Radio Search For Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Zarka, P.

    Theoretical justification and ongoing observational efforts in view of detecting radio emissions from extrasolar planets will be presented. On the "prediction" side, a heuris- tic scaling law has been established relating the radio output of any magnetized flow- obstacle system to the incident magnetic energy flux on the obstacle. Its confirmation by the observation of radio emission from extrasolar planets would help to understand the energy budget of such a system. On the "detection" side, specific procedures have been developed for interference mitigation and weak burst detection.

  18. Recurrent Activity in Radio Galaxies

    SciTech Connect

    Jamrozy, Marek; Konar, Chiranjib; Machalski, Jerzy; Mack, Karl-Heinz; Saikia, Dhruba; Siemiginowska, Aneta; Stawarz, Lukasz; /KIPAC, Menlo Park /Jagiellonian U.

    2007-10-15

    One of the outstanding issues concerning extragalactic radio sources is the total duration of their active phase and the possible existence of duty cycles of their nuclear activity. A duty cycle can be recognized if there is a mechanism which preserves the information of past activity for a sufficiently long time after a new activity has started up. If a new cycle starts before the radio lobes created during a former activity period have faded, we can recognize this by the observations of a young radio source embedded in an old relic structure.

  19. Searches for Fast Radio Transients

    NASA Astrophysics Data System (ADS)

    Cordes, J. M.; McLaughlin, M. A.

    2003-10-01

    We discuss optimal detection of fast radio transients from astrophysical objects while taking into account the effects of propagation through intervening ionized media, including dispersion, scattering, and scintillation. Our analysis applies to the giant-pulse phenomenon exhibited by some pulsars, for which we show examples, and to radio pulses from other astrophysical sources, such as prompt radio emission from gamma-ray burst sources and modulated signals from extraterrestrial civilizations. We estimate scintillation parameters for extragalactic sources that take into account scattering both in the host galaxy and in foreground Galactic plasma.

  20. The Helios radio astronomy experiment

    NASA Technical Reports Server (NTRS)

    Kayser, S.; Stone, R.

    1984-01-01

    Radio bursts traveling between the Sun and the Earth were tracked by radio astronomy experiments on Helios 1 and 2. A relatively short dipole antenna with a well-defined toroidal reception pattern was flown. The antenna spins in the ecliptic at 60.3 rpm and 2 frequencies are measured in each revolution. The signal analysis determines the strength of the signal, the direction of the source in the ecliptic, and the degree of modulation, and estimates source size. The experiments provide three-dimensional direction finding in space. They extend the radio frequency window beyond what is observable on Earth, and offer a long triangulation baseline.

  1. The excess radio background and fast radio transients

    SciTech Connect

    Kehayias, John; Kephart, Thomas W.; Weiler, Thomas J. E-mail: thomas.w.kephart@vanderbilt.edu

    2015-10-01

    In the last few years ARCADE 2, combined with older experiments, has detected an additional radio background, measured as a temperature and ranging in frequency from 22 MHz to 10 GHz, not accounted for by known radio sources and the cosmic microwave background. One type of source which has not been considered in the radio background is that of fast transients (those with event times much less than the observing time). We present a simple estimate, and a more detailed calculation, for the contribution of radio transients to the diffuse background. As a timely example, we estimate the contribution from the recently-discovered fast radio bursts (FRBs). Although their contribution is likely 6 or 7 orders of magnitude too small (though there are large uncertainties in FRB parameters) to account for the ARCADE 2 excess, our development is general and so can be applied to any fast transient sources, discovered or yet to be discovered. We estimate parameter values necessary for transient sources to noticeably contribute to the radio background.

  2. Multi-User Performance Issues in Wireless Impulse Radio Networks

    DTIC Science & Technology

    2004-01-01

    Enabling uwb through precise timing. In UWBST02, 2002. [12] R. Fontana , A. Ameti, E. Richley, L. Beard, and D. Guy. Recent advances in ultra wideband...Gabriella Di Benedetto . Multi user interference in power-unbalanced ultra wide band systems: Analysis and verification. In UWBST 03, 2003. [31] G. D

  3. The Business of Radio Promotion.

    ERIC Educational Resources Information Center

    Hall, Jonathan

    This speech suggests that public radio stations should examine and use the techniques employed by commercial stations to increase their listening audience--creative promotion based on community involvement and participation. Some examples are included. (SC)

  4. Radio astronomy - The next decade

    NASA Astrophysics Data System (ADS)

    Kellermann, Kenneth I.

    1991-09-01

    Discoveries made over the past several decades by radio astronomers include radio galaxies, quasars, pulsars, gravitational lenses, energetic bursts from the sun and Jupiter, the greenhouse effect on Venus, the rotation of Mercury, giant molecular clouds, violent activity in galactic nuclei, and cosmic background radiation. This paper discusses the development of ever more powerful radio telescopes, which include the VLA operated by NRAO near Socorro (New Mexico); the new NRAO's 100-m Green Bank Telescope being constructed in Green Bank (West Virginia); and the proposed Millimeter Array, which will consist of 40 antennas, each 8-m across, arranged in any of four different ways depending on the size of the region under study. Consideration is also given to methods for increasing the resolving power and image quality of radio telescopes, with special attention given to very-long-baseline interferometry.

  5. Facilities for radio-iodination.

    PubMed

    Ramsey, N W; Bhattacharyya, A K; Dunn, M J

    1980-02-01

    A fume cabinet with a sloping front, fitted with a chemical absorbing filter and extractor fan, but without exhaust ducting, appears to possess considerable advantages for radio-iodination work compared with standard fume cupboards.

  6. EVA Radio DRATS 2011 Report

    NASA Technical Reports Server (NTRS)

    Swank, Aaron J.; Bakula, Casey J.

    2012-01-01

    In the Fall of 2011, National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) participated in the Desert Research and Technology Studies (DRATS) field experiments held near Flagstaff, Arizona. The objective of the DRATS outing is to provide analog mission testing of candidate technologies for space exploration, especially those technologies applicable to human exploration of extra- terrestrial rocky bodies. These activities are performed at locations with similarities to extra-terrestrial conditions. This report describes the Extravehicular Activity (EVA) Dual-Band Radio Communication System which was demonstrated during the 2011 outing. The EVA radio system is designed to transport both voice and telemetry data through a mobile ad hoc wireless network and employs a dual-band radio configuration. Some key characteristics of this system include: 1. Dual-band radio configuration. 2. Intelligent switching between two different capability wireless networks. 3. Self-healing network. 4. Simultaneous data and voice communication.

  7. 46 CFR 15.830 - Radio officers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Radio officers. 15.830 Section 15.830 Shipping COAST... Computations § 15.830 Radio officers. Radio officers are required on certain merchant vessels of the United States. The determination of when a radio officer is required is based on the Federal...

  8. 75 FR 66709 - Commercial Radio Operators Rules

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... COMMISSION 47 CFR Parts 0, 1, 13, 80, and 87 Commercial Radio Operators Rules AGENCY: Federal Communications... radio operator licenses for maritime and aviation radio stations who perform certain functions performed within the commercial radio operators service, to determine which rules can be clarified, streamlined,...

  9. 46 CFR 15.830 - Radio officers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Radio officers. 15.830 Section 15.830 Shipping COAST... Computations § 15.830 Radio officers. Radio officers are required on certain merchant vessels of the United States. The determination of when a radio officer is required is based on the Federal...

  10. 46 CFR 15.830 - Radio officers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Radio officers. 15.830 Section 15.830 Shipping COAST... Computations § 15.830 Radio officers. Radio officers are required on certain merchant vessels of the United States. The determination of when a radio officer is required is based on the Federal...

  11. 46 CFR 15.830 - Radio officers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Radio officers. 15.830 Section 15.830 Shipping COAST... Computations § 15.830 Radio officers. Radio officers are required on certain merchant vessels of the United States. The determination of when a radio officer is required is based on the Federal...

  12. 46 CFR 15.830 - Radio officers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Radio officers. 15.830 Section 15.830 Shipping COAST... Computations § 15.830 Radio officers. Radio officers are required on certain merchant vessels of the United States. The determination of when a radio officer is required is based on the Federal...

  13. PARTNeR: Radio astromony for students

    NASA Astrophysics Data System (ADS)

    Blasco, C.; Vaquerizo, J. A.

    2008-06-01

    PARTNeR stands for Proyecto Academico con el Radiotelescopio de NASA en Robledo (the Academic Project with NASA's radio telescope at Robledo), and allows students to perform radio astronomy observations. High school and university students can access the PARTNeR radio telescope via the internet. The students can operate the antenna from their own school or university and perform radio astronomy observations.

  14. Innovativeness and the Public Radio Audience.

    ERIC Educational Resources Information Center

    Williams, Wenmouth, Jr.; Krugman, Dean M.

    1981-01-01

    A public radio audience was surveyed to test the hypothesis that a relationship exists between innovativeness and public radio listening. Rather than supporting the hypothesis, findings indicate that the entertainment and information elements of public radio are the primary attractions for the public radio audience. (MER)

  15. Radio Implementation of a Testbed For Cognitive Radio Source Localization Using USRPS and GNU Radio

    DTIC Science & Technology

    2014-09-01

    pp. 116–130, 2009. [4] R.A. Rashid , M.A. Sarijari, N. Fisal, S.K.S. Yusof and N.H. Mahalin, “Spectrum sensing measurement using GNU Radio and...USRP software radio platform,” in Proc. 7th Int. Conf. Wireless and Mobile Commun., Luxembourg, 2011. [5] R.A. Rashid , M.A. Sarijari, N. Fisal...Sarijari, A. Marwanto, N. Fisal, S.K.S. Yusof and R.A Rashid , “Energy detection sensing based on GNU Radio and USRP: An analysis study,” in Proc

  16. Ondvrejov solar radio WWW page

    NASA Astrophysics Data System (ADS)

    Jivrivcka, Karel; Meszarosova, Hana

    Since mid 1997 the Solar Radio Astronomy Group of the Astronomical Institute in Ondvrejov has been running a new WWW page. You can find us at the address --- http://sunkl.asu.cas.cz/radio/ --- where information about our instruments, observed frequencies, as well as about our data archive is available. The home page includes four main topics: 1. Observation & Instrumentation --- here you can find information about which instruments are currently in use, observed frequencies, time resolutions etc. Presently we use for solar radio observations three dedicated instruments: RT3 -- single frequency 3 GHz receiver with 10 ms time resolution RT4 -- radio spectrograph 2.0--4.5 GHz with 100 ms time resolution RT5 -- radio spectrograph 0.8--2.0 GHz with 100 ms time resolution The observations are run daily, while the Sun is higher then 5 degrees above the horizon. Because of the tremendous amount of data, only chosen time intervals with radio events are archived. Event Archive Info: --- here you can find information about archived data (date, time interval) as well as overall images of individual events in GIF format (the image names are at the same time hyperlinks for direct loading) sorted by date and time of observation. Gallery: --- here you can find some representative examples of spectra of solar radio events, recorded by our instruments. Anonymous FTP Server: --- enables direct FTP access to our image archive. This WWW page should give you an insight, what data are available and what the events look roughly like. The uncalibrated rough data from our archive can be processed only by special programs and are not generally free. But if you are interested in a particular event from our archive, you can contact us via e-mail address: radio@asu.cas.cz This work has been supported by the Czech Academy of Sciences through grant no.A3003707.

  17. Populations of extragalactic radio sources

    NASA Astrophysics Data System (ADS)

    Wall, J. V.

    In the late 1950s and early 1960s, radio sky surveys were the center of an intense and public debate -- Big-Bang versus Steady-State cosmology -- the arguments revolving about source counts and statistical interpretations in the face of instrumental complications. The 1965 discovery of the microwave background took the fire from the debate, but left the momentum in place for large-area radio surveys at different frequencies, and for extensive identification/redshift-measurement programs. By the 1970s the data enabled us to start disentangling the different populations of extragalactic radio sources. We could refine our taxonomy, and we could view the possibility of delineating individual cosmic histories and evolutions. We could at least describe a goal to elucidate the birth-life-death cycles of the objects involved 1quasi-stellar objects (QSOs) and radio galaxies: together the 'active galactic nuclei' (AGNs)1 whose unaccountably prodigious energies somehow produce the beautifully aligned radio structures with which we are now familiar. One part of John Bolton's vision was to see how distorted a view of the AGN universe the original long-wavelength surveys provided. One legacy is thus the 'short-wavelength survey' for extragalactic radio sources, which has done so much to balance our picture of the radio sky. And indeed the legacy continues in the form of the immense sky surveys at present under way, complete with their sub-industries of radio-positioning and identification. From these, yet further results are emerging on spatial distribution and the skeleton structure of the universe. It is the purpose of this paper to outline something of this current view of the populations, their differences, similarities and unifying concepts.

  18. National Centre for Radio Astrophysics

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    India's National Centre for Radio Astrophysics (NCRA), located on the Pune University Campus, is part of the TATA INSTITUTE OF FUNDAMENTAL RESEARCH. At Khodad, 80 km from Pune, NCRA has set up the Giant Metrewave Radio Telescope (GMRT), the world's largest telescope operating at meter wavelengths. GMRT consists of 30 fully steerable dishes of 45 m diameter, spread over a 25 km area. Another meter...

  19. Historic Radio Astronomy Working Group

    NASA Astrophysics Data System (ADS)

    2007-06-01

    This special issue of Astronomische Nachrichten contains the proceedings of a session of the Historic Radio Astronomy Working Group of the International Astronomical Union that took place during the 26th General Assembly of the IAU in Prague on 17th August 2006. In addition to the talks presented in Prague some contributions were solicited to give a more complete overview of `The Early History of European Radio Astronomy'.

  20. Radio emission from supernova remnants

    NASA Astrophysics Data System (ADS)

    Dubner, Gloria; Giacani, Elsa

    2015-09-01

    The explosion of a supernova releases almost instantaneously about 10^{51} ergs of mechanic energy, changing irreversibly the physical and chemical properties of large regions in the galaxies. The stellar ejecta, the nebula resulting from the powerful shock waves, and sometimes a compact stellar remnant, constitute a supernova remnant (SNR). They can radiate their energy across the whole electromagnetic spectrum, but the great majority are radio sources. Almost 70 years after the first detection of radio emission coming from an SNR, great progress has been achieved in the comprehension of their physical characteristics and evolution. We review the present knowledge of different aspects of radio remnants, focusing on sources of the Milky Way and the Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief overview of theoretical background, analyze morphology and polarization properties, and review and critically discuss different methods applied to determine the radio spectrum and distances. The consequences of the interaction between the SNR shocks and the surrounding medium are examined, including the question of whether SNRs can trigger the formation of new stars. Cases of multispectral comparison are presented. A section is devoted to reviewing recent results of radio SNRs in the Magellanic Clouds, with particular emphasis on the radio properties of SN 1987A, an ideal laboratory to investigate dynamical evolution of an SNR in near real time. The review concludes with a summary of issues on radio SNRs that deserve further study, and analysis of the prospects for future research with the latest-generation radio telescopes.

  1. A zero-power radio receiver.

    SciTech Connect

    Brocato, Robert Wesley

    2004-09-01

    This report describes both a general methodology and some specific examples of passive radio receivers. A passive radio receiver uses no direct electrical power but makes sole use of the power available in the radio spectrum. These radio receivers are suitable as low data-rate receivers or passive alerting devices for standard, high power radio receivers. Some zero-power radio architectures exhibit significant improvements in range with the addition of very low power amplifiers or signal processing electronics. These ultra-low power radios are also discussed and compared to the purely zero-power approaches.

  2. Natural radio lasing at Jupiter

    NASA Technical Reports Server (NTRS)

    Calvert, W.; Leblanc, Y.; Ellis, G. R. A.

    1988-01-01

    Like the comparable AKR radio emissions from earth's magnetosphere, the well-known decametric radio S-bursts from Jupiter, observed in France and Australia at frequencies from 10 to 26 MHz, have been found to exhibit equally spaced discrete spectral components which can be attributed to the adjacent longitudinal oscillation modes of natural radio lasers. Implying sizes of only a few kilometers for the individual radio lasers producing the S-bursts, the frequency spacing of these modes was roughly constant with frequency and about 30 to 50 kHz. Their corresponding temporal spacings, however, varied inversely proportional to the observing frequency, suggesting that the radio lasers producing the S-bursts were expanding uniformly at a rate of about 4 km/s. Presumably caused by the projected motion of Io with respect to the planet, this expansion of the S-burst radio lasers would account for the downward frequency drifts of the S-bursts without the energetic electron bunches which have heretofore always been assumed necessary to account for such behavior.

  3. Radio galaxies and their environment

    SciTech Connect

    van Breugel, W.

    1993-02-24

    The relationships between radio galaxies and their environment are varied, complex, and evolve with cosmic epoch. Basic questions are what role the environment plays in triggering and fuelling (radio) galaxy activity what the effects of this activity are on its environment, and how radio galaxies and environment evolve. Clearly, this could be the topic of a workshop all in itself and the scope of this review will necessarily be limited. A review of the connections between environment and galaxy activity in general has been given by Heckman. First, I will briefly summarize the relationships between parent galaxy and cluster environments, and radio galaxies. A more detailed discussion of various aspects of this will be given elsewhere by F. Owen, J.0. Burns and R. Perley. I will then discuss the current status of investigations of extended emission-line regions in radio galaxies, again referring elsewhere in this volume for more detailed discussions of some particular aspects (kinematics and ionization mechanisms by K. Meisenheimer; polarization and spectral index lobe asymmetries by G. Pooley). I will conclude with a brief discussion of the current status of observations of high redshift radio galaxies.

  4. Flare stars at radio wavelengths

    NASA Technical Reports Server (NTRS)

    Lang, Kenneth R.

    1990-01-01

    The radio emission from dMe flare stars is discussed using Very Large Array and Arecibo observations as examples. Active flare stars emit weak, unpolarized, quiescent radio radiation that may be always present. Although thermal bremsstrahlung and/or thermal gyroresonance radiation account for the slowly-varying, quiescent radio radiation of solar active regions, these processes cannot account for the long-wavelength quiescent radiation observed from nearby dMe flare stars. It has been attributed to nonthermal gyrosynchrotron radiation, but some as yet unexplained mechanism must be continually producing the energetic electrons. Long duration, narrow-band radiation is also emitted from some nearby dMe stars at 20 cm wavelength. Such radiation may be attributed to coherent plasma radiation or to coherent electron-cyclotron masers. Impulsive stellar flares exhibit rapid variations that require radio sources that are smaller than the star in size, and high brightness temperatures greater than 10(exp 15) K that are also explained by coherent radiation processes. Quasi-periodic temporal fluctuations suggest pulsations during some radio flares. Evidence for frequency structure and positive or negative frequency drifts during radio flares from dMe stars is also presented.

  5. Flare stars at radio wavelengths

    NASA Technical Reports Server (NTRS)

    Lang, Kenneth R.

    1989-01-01

    The radio emission from dMe flare stars is discussed using Very Large Array and Arecibo observations as examples. Active flare stars emit weak, unpolarized, quiescent radio radiation that may be always present. Although thermal bremsstrahlung and/or thermal gyroresonance radiation account for the slowly-varying, quiescent radio radiation of solar active regions, these processes cannot account for the long-wavelength quiescent radiation observed from nearby dMe flare stars. It has been attributed to nonthermal gyrosynchrotron radiation, but some as yet unexplained mechanism must be continually producing the energetic electrons. Long duration, narrow-band radiation is also emitted from some nearby dMe stars at 20 cm wavelength. Such radiation may be attributed to coherent plasma radiation or to coherent electron-cyclotron masers. Impulsive stellar flares exhibit rapid variations that require radio sources that are smaller than the star in size, and high brightness temperatures greater than 10(exp 15) K that are also explained by coherent radiation processes. Quasi-periodic temporal fluctuations suggest pulsations during some radio flares. Evidence for frequency structure and positive or negative frequency drifts during radio flares from dMe stars is also presented.

  6. The radio properties of infrared-faint radio sources

    NASA Astrophysics Data System (ADS)

    Middelberg, E.; Norris, R. P.; Hales, C. A.; Seymour, N.; Johnston-Hollitt, M.; Huynh, M. T.; Lenc, E.; Mao, M. Y.

    2011-02-01

    Context. Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4 GHz, but that are invisible at 3.6 μm when using sensitive Spitzer observations with μJy sensitivities. Their nature is unclear and difficult to investigate since they are only visible in the radio. Aims: High-resolution radio images and comprehensive spectral coverage can yield constraints on the emission mechanisms of IFRS and can give hints to similarities with known objects. Methods: We imaged a sample of 17 IFRS at 4.8 GHz and 8.6 GHz with the Australia Telescope Compact Array to determine the structures on arcsecond scales. We added radio data from other observing projects and from the literature to obtain broad-band radio spectra. Results: We find that the sources in our sample are either resolved out at the higher frequencies or are compact at resolutions of a few arcsec, which implies that they are smaller than a typical galaxy. The spectra of IFRS are remarkably steep, with a median spectral index of -1.4 and a prominent lack of spectral indices larger than -0.7. We also find that, given the IR non-detections, the ratio of 1.4 GHz flux density to 3.6 μm flux density is very high, and this puts them into the same regime as high-redshift radio galaxies. Conclusions: The evidence that IFRS are predominantly high-redshift sources driven by active galactic nuclei (AGN) is strong, even though not all IFRS may be caused by the same phenomenon. Compared to the rare and painstakingly collected high-redshift radio galaxies, IFRS appear to be much more abundant, but less luminous, AGN-driven galaxies at similar cosmological distances.

  7. Brown University Radio Student Telescope (BURST)

    NASA Astrophysics Data System (ADS)

    Miller, Michelle

    2017-01-01

    The Brown University Radio Student Telescope (BURST) is a rooftop low frequency radio interferometer that we hope to potentially use to observe radio transients, non-thermal radio emission from Galactic synchrotron and supernova remnants, and extragalactic radio sources. It was built by a group of Brown undergraduates this past summer. An overview of the design, ultimate installation, challenges in implementation and data acquisition will be covered in the poster.

  8. Recycling for radio astronomy

    NASA Astrophysics Data System (ADS)

    Hoare, Melvin

    2012-02-01

    Melvin Hoare, Steve Rawlings and the CUGA consortium look forward to the potential offered by recycling the ˜30 m class antennas at Goonhilly Earth Station in Cornwall, including a new deep-space tracking facility, research and training, and the possibility of enhancing the e-MERLIN array.

  9. Satellite triangulation of thunderstorms, from fading radio fields synchronously recorded on two orthogonal antennas

    NASA Astrophysics Data System (ADS)

    Jacobson, Abram R.; Shao, Xuan-Min; Holzworth, Robert H.

    2011-12-01

    Single-satellite observations of lightning radio emissions normally do not independently provide useful thunderstorm location. The scientific value of these radio waveform recordings is greatly enhanced by knowing at least the approximate location of the source thunderstorm. Since the Very High Frequency radio emissions from lightning are always broadband and usually incoherent, radio interferometry is an obvious approach to direction-finding the source. However, radio-interferometry requires separated, deployed antennas, and for decametric radio waves, success with interferometric direction-finding on a satellite has not yet been reported. We describe a method for approximate location of source thunderstorms, using the statistical fading of the received electric field on two orthogonal, but co-located, antennas. The method is based on previous work geolocating polarized sources, and we show that it can be adapted efficiently to unpolarized radio fields, which constitute the majority of lightning emissions. We implement the method with dual-antenna radio recordings from the FORTE satellite, and demonstrate its capabilities using a wide variety of radio data.

  10. Reconciling CME Kinematics using Radio and White-light Observations from STEREO and SOHO

    NASA Astrophysics Data System (ADS)

    Gopalswamy, Nat; Yashiro, Seiji; Xie, Hong; Makela, Pertti; Akiyama, Sachiko; Reiner, Michael; MacDowall, Robert

    2014-05-01

    We study the characteristics of nonthermal radio emission associated with coronal mass ejections (CMEs) observed by STEREO, SOHO, and Wind spacecraft. In particular, we examine three backside CMEs associated with type II radio bursts at frequencies below 16 MHz. These bursts are known to be excellent indicators of solar energetic particle events. We use the universal drift rate spectrum of type II radio bursts and the inferred density scale heights in the corona and interplanetary medium o estimate the speed of the shock waves that produce the type II radio bursts. We find that the radio bursts can provide an accurate estimate of the CME speeds. We consider three backside events and a cannibalism event to show the usefulness of radio dynamic spectrum in inferring CME kinematics. We use radio direction finding technique to show that CME-CME interaction results in enhanced nonthermal radio emission. The radio data also provide constraints on the particle acceleration mechanisms and the reason for the energetic particles observed at wide-ranging longitudes. Finally we infer the shape and extent of the shock associated with one of the biggest solar energetic particle events in the space era.

  11. Radio detection of high-energy cosmic rays with the Auger Engineering Radio Array

    NASA Astrophysics Data System (ADS)

    Schröder, Frank G.

    2016-07-01

    The Auger Engineering Radio Array (AERA) is an enhancement of the Pierre Auger Observatory in Argentina. Covering about 17km2, AERA is the world-largest antenna array for cosmic-ray observation. It consists of more than 150 antenna stations detecting the radio signal emitted by air showers, i.e., cascades of secondary particles caused by primary cosmic rays hitting the atmosphere. At the beginning, technical goals had been in focus: first of all, the successful demonstration that a large-scale antenna array consisting of autonomous stations is feasible. Moreover, techniques for calibration of the antennas and time calibration of the array have been developed, as well as special software for the data analysis. Meanwhile physics goals come into focus. At the Pierre Auger Observatory air showers are simultaneously detected by several detector systems, in particular water-Cherenkov detectors at the surface, underground muon detectors, and fluorescence telescopes, which enables cross-calibration of different detection techniques. For the direction and energy of air showers, the precision achieved by AERA is already competitive; for the type of primary particle, several methods are tested and optimized. By combining AERA with the particle detectors we aim for a better understanding of cosmic rays in the energy range from approximately 0.3 to 10 EeV, i.e., significantly higher energies than preceding radio arrays.

  12. Satellites of radio AGN in SDSS: Insights into agn triggering and feedback

    SciTech Connect

    Pace, Cameron; Salim, Samir E-mail: salims@indiana.edu

    2014-04-10

    We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best and Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ∼1% of radio AGN.

  13. Satellites of Radio AGN in SDSS: Insights into AGN Triggering and Feedback

    NASA Astrophysics Data System (ADS)

    Pace, Cameron; Salim, Samir

    2014-04-01

    We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best & Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ~1% of radio AGN.

  14. IA-Regional-Radio - Social Network for Radio Recommendation

    NASA Astrophysics Data System (ADS)

    Dziczkowski, Grzegorz; Bougueroua, Lamine; Wegrzyn-Wolska, Katarzyna

    This chapter describes the functions of a system proposed for the music hit recommendation from social network data base. This system carries out the automatic collection, evaluation and rating of music reviewers and the possibility for listeners to rate musical hits and recommendations deduced from auditor's profiles in the form of regional Internet radio. First, the system searches and retrieves probable music reviews from the Internet. Subsequently, the system carries out an evaluation and rating of those reviews. From this list of music hits, the system directly allows notation from our application. Finally, the system automatically creates the record list diffused each day depending on the region, the year season, the day hours and the age of listeners. Our system uses linguistics and statistic methods for classifying music opinions and data mining techniques for recommendation part needed for recorded list creation. The principal task is the creation of popular intelligent radio adaptive on auditor's age and region - IA-Regional-Radio.

  15. Sharing Low Frequency Radio Emissions in the Virtual Observatory: Application for JUNO-Ground-Radio Observations Support.

    NASA Astrophysics Data System (ADS)

    Cecconi, B.; Savalle, R.; Zarka, P. M.; Anderson, M.; Andre, N.; Coffre, A.; Clarke, T.; Denis, L.; Ebert, R. W.; Erard, S.; Genot, V. N.; Girard, J. N.; Griessmeier, J. M.; Hess, S. L.; Higgins, C. A.; Hobara, Y.; Imai, K.; Imai, M.; Kasaba, Y.; Konovalenko, A. A.; Kumamoto, A.; Kurth, W. S.; Lamy, L.; Le Sidaner, P.; Misawa, H.; Nakajo, T.; Orton, G. S.; Ryabov, V. B.; Sky, J.; Thieman, J.; Tsuchiya, F.; Typinski, D.

    2015-12-01

    In the frame of the preparation of the NASA/JUNO and ESA/JUICE (Jupiter Icy Moon Explorer) missions, and the development of a planetary sciences virtual observatory (VO), we are proposing a new set of tools directed to data providers as well as users, in order to ease data sharing and discovery. We will focus on ground based planetary radio observations (thus mainly Jupiter radio emissions), trying for instance to enhance the temporal coverage of jovian decametric emission. The data service we will be using is EPN-TAP, a planetary science data access protocol developed by Europlanet-VESPA (Virtual European Solar and Planetary Access). This protocol is derived from IVOA (International Virtual Observatory Alliance) standards. The Jupiter Routine Observations from the Nancay Decameter Array are already shared on the planetary science VO using this protocol, as well as data from the Iitate Low Frquency Radio Antenna, in Japan. Amateur radio data from the RadioJOVE project is also available. The attached figure shows data from those three providers. We will first introduce the VO tools and concepts of interest for the planetary radioastronomy community. We will then present the various data formats now used for such data services, as well as their associated metadata. We will finally show various prototypical tools that make use of this shared datasets.

  16. a Radio-Frequency

    NASA Astrophysics Data System (ADS)

    Foo, Thomas Kwok-Fah

    Radio-frequency (RF) inhomogeneity encountered in magnetic resonance (MR) imaging poses a significant impediment to obtaining images of the highest diagnostic quality. This inhomogeneity arises from the conductivity effect, which attenuates the RF field with increasing depth, and the permittivity effect. The latter is the dominant effect at 1.5 Tesla (64 MHz), and contributes to standing waves within the body. A theoretical model has been developed which describes these effects for an infinitely long right circularly cylindrical object inside a concentric RF coil and RF shield. This model assumes that the RF field propagates as a travelling wave in the z direction, along the long axis of the cylinder. The resulting solutions adequately predict the field distribution for RF coils which have both a finite wavelength and an infinite wavelength in z. This corresponds to high-pass and low-pass birdcage resonators, respectively, that are in general used in MR imaging. Standing wave models are easily obtained from the superposition of solutions of two travelling waves in opposite directions. The results of this model indicate that the axial propagation constant k_{z} is a strong function of the dielectric present in the coil -to-shield space. The field distribution in the axial plane can be represented by the Bessel function J_1(k _{rho}r), where k _sp{rho}{2} = k^2-k_sp{z}{2} . By varying the dielectric material occupying the coil-to-shield space, an optimum value of k _{z} can be obtained for a particular coil and shield configuration which minimizes the amplitude variations in the axial plane. Experimental verification of the theoretical model has been obtained. These measurements were performed on a non-resonant, travelling wave test coil with a saline phantom as a load simulating the body. The measured field profiles in the axial plane agree with the predicted values, establishing the validity of the theoretical model. As expected, optimal RF homogeneity was obtained

  17. Video via radio testbed

    NASA Astrophysics Data System (ADS)

    Szu, Harold H.; Hsu, Charles C.

    2002-03-01

    to enable us to transmit live video via the SINGARS radio at a narrow bandwidth of 16 K bps.

  18. Determination of the concentrations of the steroids estradiol, progesterone and testosterone in bovine sera: comparison of commercial dissociation enhanced lanthanide fluorescence immunoassay kits with conventional radio and enzyme immunoassays.

    PubMed

    Elliott, C T; Francis, K S; Shortt, H D; McCaughey, W J

    1995-06-01

    The performance of three conventional enzyme and radioimmunoassays routinely used to detect residues of anabolic steroids in cattle sera were compared with dissociation enhanced lanthanide fluorescence immunoassay (DELFIA) kits designed for the hospital market. Slight modifications to the kit reagents were required for the analysis of bovine sera. Owing to the large sample volumes used in conventional assays, detection limits were generally better than those obtained with DELFIA kits, however, assay reproducibility was enhanced using the DELFIA technology. Comparison of sera obtained from cattle implanted with anabolic steroids revealed a good correlation between alternate methods (r2 from 0.91 to 0.97). The DELFIA kits offer a faster method for measuring estradiol, progesterone and testosterone with adequate sensitivity and in a safer environment than that encountered using radioimmunoassays.

  19. LF radio wave propagation at equatorial regions

    NASA Astrophysics Data System (ADS)

    Boudjada, Mohammed Y.; Sawas, Sami; Galopeau, Patrick H. M.; Eichelberger, Hans; Schwingenschuh, Konrad

    2016-04-01

    We analyse night-side electric field observations recorded by the ICE experiment onboard the DEMETER micro-satellite. We show the presence of multiple spaced frequency bands between 30 kHz and 500 kHz, and sometimes in the range 3 MHz - 3.5 MHz, the upper frequency of the instrument. The frequency bandwidth is found to be less than 5 kHz and the time duration about several minutes. The frequency bands are recorded close to the equatorial plane, when the satellite latitudes extend between -05° and +05°. Particular enhancements occur at two geographical longitudes: 130°E and 160°W. Those LF radio waves may be associated to density irregularities in the equatorial region. These irregularities are occurring along the ray path between the emission source region and the satellite. We discuss in this study the locations where such frequency bands are generated, and we show that the observed spectral features may be comparable to the kilometric continuum radiation which is considered as a non-thermal radio emission.

  20. Jovian type III radio bursts

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.; Gurnett, D. A.; Scarf, F. L.

    1989-01-01

    Radio bursts have been observed in the Voyager plasma wave data from Jupiter that bear a striking resemblance to solar type III radio bursts. The emissions lie in the frequency range near 10 kHz, have durations of a minute or so, and occur in a set of periodically spaced bursts. The spacing between primary bursts is typically 15 min, but the bursts may have additional components which recur on time scales of about 3 min. The similarity with solar type III radio bursts suggests a source mechanism involving the movement of energetic electrons through a density gradient in the plasma surrounding Jupiter. The periodicity of bursts suggests Io may be involved in the generation of waves, since the timing is similar to the Alfven wave travel time from one hemisphere to the other through the Io torus.

  1. The development of radio astronomy

    NASA Astrophysics Data System (ADS)

    Reich, W.; Wielebinski, R.

    2002-07-01

    Following the detection of extraterrestrial radio waves in 1932 by Karl Jansky, radio astronomy developed quickly after World War II. It established itself soon as a new branch of astronomy with today's outstanding record in the detection of new phenomena in space. These have been honoured by a number of Nobel prizes. Radio astronomy largely depends on technical developments in receiver technology, antenna systems, electronics and computing power. Ever shorter wavelengths down to the submm-wavelength range became accessible, resulting in new exciting discoveries. However, now and in future care must be taken, in particular for the lower frequency range, of harmful man-made interferences, which might mask the weak signals from space. New international facilities with orders-of-magnitude higher sensitivity like ALMA and SKA are planned or under construction. Space-borne observatories like PLANCK will detect weak fluctuations of the cosmic microwave background, which will constrain cosmological models with an unprecedented accuracy.

  2. Miniature EVA Software Defined Radio

    NASA Technical Reports Server (NTRS)

    Pozhidaev, Aleksey

    2012-01-01

    As NASA embarks upon developing the Next-Generation Extra Vehicular Activity (EVA) Radio for deep space exploration, the demands on EVA battery life will substantially increase. The number of modes and frequency bands required will continue to grow in order to enable efficient and complex multi-mode operations including communications, navigation, and tracking applications. Whether conducting astronaut excursions, communicating to soldiers, or first responders responding to emergency hazards, NASA has developed an innovative, affordable, miniaturized, power-efficient software defined radio that offers unprecedented power-efficient flexibility. This lightweight, programmable, S-band, multi-service, frequency- agile EVA software defined radio (SDR) supports data, telemetry, voice, and both standard and high-definition video. Features include a modular design, an easily scalable architecture, and the EVA SDR allows for both stationary and mobile battery powered handheld operations. Currently, the radio is equipped with an S-band RF section. However, its scalable architecture can accommodate multiple RF sections simultaneously to cover multiple frequency bands. The EVA SDR also supports multiple network protocols. It currently implements a Hybrid Mesh Network based on the 802.11s open standard protocol. The radio targets RF channel data rates up to 20 Mbps and can be equipped with a real-time operating system (RTOS) that can be switched off for power-aware applications. The EVA SDR's modular design permits implementation of the same hardware at all Network Nodes concept. This approach assures the portability of the same software into any radio in the system. It also brings several benefits to the entire system including reducing system maintenance, system complexity, and development cost.

  3. Mobile radio interferometric geodetic systems

    NASA Technical Reports Server (NTRS)

    Macdoran, P. F.; Niell, A. E.; Ong, K. M.; Resch, G. M.; Morabito, D. D.; Claflin, E. S.; Lockhart, T. G.

    1978-01-01

    Operation of the Astronomical Radio Interferometric Earth Surveying (ARIES) in a proof of concept mode is discussed. Accuracy demonstrations over a short baseline, a 180 km baseline, and a 380 km baseline are documented. Use of ARIES in the Sea Slope Experiment of the National Geodetic Survey to study the apparent differences between oceanographic and geodetic leveling determinations of the sea surface along the Pacific Coast is described. Intergration of the NAVSTAR Global Positioning System and a concept called SERIES (Satellite Emission Radio Interferometric Earth Surveying) is briefly reviewed.

  4. Radio Relays Improve Wireless Products

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Signal Hill, California-based XCOM Wireless Inc. developed radio frequency micromachine (RF MEMS) relays with a Phase II Small Business Innovation Research (SBIR) contract through NASA?s Jet Propulsion Laboratory. In order to improve satellite communication systems, XCOM produced wireless RF MEMS relays and tunable capacitors that use metal-to-metal contact and have the potential to outperform most semiconductor technologies while using less power. These relays are used in high-frequency test equipment and instrumentation, where increased speed can mean significant cost savings. Applications now also include mainstream wireless applications and greatly improved tactical radios.

  5. Final report: In situ radio frequency heating demonstration

    SciTech Connect

    Jarosch, T.R.; Beleski, R.J.; Faust, D.

    1994-01-05

    A field demonstration of in situ radio frequency heating was performed at the Savannah River Site (SRS) as part of the US Department of Energy-Office of Technology Development`s Integrated Demonstration. The objective of the demonstration was to investigate the effectiveness of in situ radio frequency (RF) heating as an enhancement to vacuum extraction of residual solvents (primarily trichloroethylene and perchloroethylene) held in vadose zone clay deposits. Conventional soil vacuum extraction techniques are mass transfer limited because of the low permeabilities of the clays. By selectively heating the clays to temperatures at or above 100{degrees}C, the release or transport of the solvent vapors will be enhanced as a result of several factors including an increase in the contaminant vapor pressure and diffusivity and an increase in the effective permeability of the formation with the release of water vapor.

  6. Cosmology: Home of a fast radio burst

    NASA Astrophysics Data System (ADS)

    Lorimer, Duncan

    2016-02-01

    Our understanding of fast radio bursts -- intense pulses of radio waves -- and their use as cosmic probes promises to be transformed now that one burst has been associated with a galaxy of known distance from Earth. See Letter p.453

  7. Educational Radio: Directions in the Pacific.

    ERIC Educational Resources Information Center

    Reddy, Sachida

    1986-01-01

    This personal perspective on developments in educational radio broadcasting in some small island nations of the South Pacific discusses radio as a powerful teaching aid, curriculum development, educational communicators, printed support materials, costs, facilities duplication, and future trends. (MBR)

  8. Radio frequency power load and associated method

    NASA Technical Reports Server (NTRS)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2010-01-01

    A radio frequency power load and associated method. A radio frequency power load apparatus includes a container and a fluid having an ion source therein, the fluid being contained in the container. Two conductors are immersed in the fluid. A radio frequency transmission system includes a radio frequency transmitter, a radio frequency amplifier connected to the transmitter and a radio frequency power load apparatus connected to the amplifier. The apparatus includes a fluid having an ion source therein, and two conductors immersed in the fluid. A method of dissipating power generated by a radio frequency transmission system includes the steps of: immersing two conductors of a radio frequency power load apparatus in a fluid having an ion source therein; and connecting the apparatus to an amplifier of the transmission system.

  9. Modulated spectral activity (MSA) - Implications for planetary radio sources

    NASA Astrophysics Data System (ADS)

    Thieman, James R.; Alexander, Joseph K.; Staelin, David H.

    The properties of the Jovian and Saturnian MSA, modulation patterns within the normally diffuse nonthermal radio emission that are characterized by distinctive banded structures of enhanced intensity fluctuations in frequency over time scales of minutes to tens of minutes, are discussed. Although Jovian and Saturnian MSA are both normally observed in the 0.2-1.3-MHz frequency range, similar pattern have been noted in Jovian decametric emission above 30 MHz. The MSA properties are used to constrain the possible source mechanism.

  10. Modulated spectral activity (MSA) - Implications for planetary radio sources

    NASA Technical Reports Server (NTRS)

    Thieman, James R.; Alexander, Joseph K.; Staelin, David H.

    1988-01-01

    The properties of the Jovian and Saturnian MSA, modulation patterns within the normally diffuse nonthermal radio emission that are characterized by distinctive banded structures of enhanced intensity fluctuations in frequency over time scales of minutes to tens of minutes, are discussed. Although Jovian and Saturnian MSA are both normally observed in the 0.2-1.3-MHz frequency range, similar pattern have been noted in Jovian decametric emission above 30 MHz. The MSA properties are used to constrain the possible source mechanism.

  11. Radio Frequency Heating for Soil Remediation.

    PubMed

    Price, Stephen L; Kasevich, Raymond S; Johnson, Mark A; Wiberg, Dan; Marley, Michael C

    1999-02-01

    Radio frequency heating (RFH) is a technology that increases the cost-effectiveness of a variety of site remediation technologies by accelerating the rate of contaminant removal. Heating makes the physical, chemical, and biological properties of materials such as contaminants, soil, and groundwater more amenable to remediation. RFH brings controlled heating to the subsurface, enhancing the removal of contaminants by soil vapor extraction (SVE), groundwater aeration (air sparging), bioremediation, and product recovery. The results presented are from a bench-scale study and a field demonstration that both used RFH to enhance the performance of SVE. The bench-scale study performed on PCE-contaminated soil revealed an increase, by a factor of 8, in the removal rate when RFH was used to heat soil to 90 °C. The application of RFH for a three-week period at a former gasoline station near St. Paul, MN, resulted in raising the ambient soil temperature from 8 °C to 100 °C in the immediate vicinity of the RFH applicator and to 40 °C 1.5 m (5 ft) away. Most significantly, the use of an integrated RFH/SVE system achieved an overall 50% reduction in gasoline range organics (GRO) in soil over a two- to three-month period. The discussion includes applications of RFH for enhancing bioremediation and product recovery.

  12. No radio pulsations detected from SGR 1627-41 following renewed X- ray activity

    NASA Astrophysics Data System (ADS)

    Camilo, F.; Sarkissian, J.

    2008-06-01

    Starting on May 28, 2008, the SGR 1627-41 displayed X-ray bursting and enhanced flux after nearly 10 years of relative inactivity (ATEL #1548, #1549, #1555). Two magnetars are known to emit radio pulses (Camilo et al. 2007, ApJ, 666, L93), and in at least one case these are transient and have followed an X-ray outburst after many years in quiescence (Camilo et al. 2006, Nature, 442, 892). Therefore, although previous radio searches of SGR 1627-41 have been unsuccessful, we are searching for radio emission following its recent renewed burst of activity.

  13. Space Telecommunications Radio System (STRS) Architecture Standard. Release 1.02.1

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.; Kacpura, Thomas J.; Handler, Louis M.; Hall, C. Steve; Mortensen, Dale J.; Johnson, Sandra K.; Briones, Janette C.; Nappier, Jennifer M.; Downey, Joseph A.; Lux, James P.

    2012-01-01

    This document contains the NASA architecture standard for software defined radios used in space- and ground-based platforms to enable commonality among radio developments to enhance capability and services while reducing mission and programmatic risk. Transceivers (or transponders) with functionality primarily defined in software (e.g., firmware) have the ability to change their functional behavior through software alone. This radio architecture standard offers value by employing common waveform software interfaces, method of instantiation, operation, and testing among different compliant hardware and software products. These common interfaces within the architecture abstract application software from the underlying hardware to enable technology insertion independently at either the software or hardware layer.

  14. The origin of radio bursts of pulsar J0643+80

    NASA Astrophysics Data System (ADS)

    Machabeli, G.; Malofeev, V. M.; Gogoberidze, G.

    2017-03-01

    We develop a model to explain flares observed at a frequency of 111 MHz in the radiation of pulsar J0643+80. We consider non-linear processes in the electron-positron plasma of the pulsar magnetosphere and show that these interactions can cause self-trapping of radio emission in narrow bands of frequencies. This mechanism can explain the origin of the observed flares without any additional sources of radio emission. The proposed scenario naturally explains why strong enhancement of the radio emission does not affect radiation in other frequency bands.

  15. Kashima 34-m Radio Telescope

    NASA Technical Reports Server (NTRS)

    Sekido, Mamoru; Kawai, Eiji

    2013-01-01

    The Kashima 34-m radio telescope has been continuously operated and maintained by the National Institute of Information and Communications Technology (NICT) as a facility of the Kashima Space Technology Center (KSTC) in Japan. This brief report summarizes the status of this telescope, the staff, and activities during 2012.

  16. RadioActive101 Practices

    ERIC Educational Resources Information Center

    Brites, Maria José; Ravenscroft, Andrew; Dellow, James; Rainey, Colin; Jorge, Ana; Santos, Sílvio Correia; Rees, Angela; Auwärter, Andreas; Catalão, Daniel; Balica, Magda; Camilleri, Anthony F.

    2014-01-01

    In keeping with the overarching RadioActive101 (RA101) spirit and ethos, this report is the product of collaborative and joined-up thinking from within the European consortium spread across five countries. As such, it is not simply a single voice reporting on the experiences and knowledge gained during the project. Rather it is a range of…

  17. Hybrid spread spectrum radio system

    DOEpatents

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  18. Radio Days in the Classroom

    ERIC Educational Resources Information Center

    Schuchat, Dan

    2005-01-01

    What social studies project challenges students with interdisciplinary learning, engages their various abilities and learning styles, offers them the opportunity for collaborative work-and encourages them to speak in strange voices? The answer is an eighth grade radio drama project. For most of the month of March 2004, the entire eighth grade at…

  19. Exploring the Dynamic Radio Sky

    NASA Astrophysics Data System (ADS)

    Mooley, Kunal; Horesh, A.; Hallinan, G.; Bourke, S.; Kulkarni, S. R.; Frail, D. A.; Ofek, E.

    2013-01-01

    The dynamic radio sky remains a rich area for discovery. Taking advantage of the new capabilities of the Jansky-VLA, we have carried out a near-real-time survey for radio transients in the SDSS Stripe 82 region. We observed 50 sq. deg. at 3 GHz at 3 epochs separated by 1 week and 1 month with 75uJy rms. In contrast to previous surveys, our survey is coupled with contemporaneous optical monitoring (with the Palomar Transient Factory) and rapid follow-up (at X-ray through radio frequencies), enabling physical interpretation of the detected transients. Supernovae, non-thermal tidal disruption events (TDEs), stellar flares, orphan long-duration Gamma Ray Bursts (GRBs) and NS-NS coalescence events are among those which we expect to see. Such detections will have large impact on several key questions such as the rate of TDEs, obscured supernovae, the beaming factor of GRBs and the rate of NS-NS mergers. This systematic search for transient and variable radio sources is meant to be a fore-runner of next-generation surveys planned for WSRT/Apertif, ASKAP, LOFAR and MeerKAT.

  20. Radio Monitoring of Protoplanetary Discs

    NASA Astrophysics Data System (ADS)

    Ubach, C.; Maddison, S. T.; Wright, C. M.; Wilner, D. J.; Lommen, D. J. P.; Koribalski, B.

    2017-01-01

    Protoplanetary disc systems observed at radio wavelengths often show excess emission above that expected from a simple extrapolation of thermal dust emission observed at short millimetre wavelengths. Monitoring the emission at radio wavelengths can be used to help disentangle the physical mechanisms responsible for this excess, including free-free emission from a wind or jet, and chromospheric emission associated with stellar activity. We present new results from a radio monitoring survey conducted with Australia Telescope Compact Array over the course of several years with observation intervals spanning days, months and years, where the flux variability of 11 T Tauri stars in the Chamaeleon and Lupus star forming regions was measured at 7 and 15 mm and 3 and 6 cm. Results show that for most sources are variable to some degree at 7 mm, indicating the presence of emission mechanisms other than thermal dust in some sources. Additionally, evidence of grain growth to cm-sized pebbles was found for some sources that also have signs of variable flux at 7 mm. We conclude that multiple processes contributing to the emission are common in T Tauri stars at 7 mm and beyond, and that a detection at a single epoch at radio wavelengths should not be used to determine all processes contributing to the emission.

  1. Low Frequency Radio Experiment (LORE)

    NASA Astrophysics Data System (ADS)

    Manoharan, P. K.; Naidu, Arun; Joshi, B. C.; Roy, Jayashree; Kate, G.; Pethe, Kaiwalya; Galande, Shridhar; Jamadar, Sachin; Mahajan, S. P.; Patil, R. A.

    2016-03-01

    In this paper, we present a case study of Low Frequency Radio Experiment (LORE) payload to probe the corona and the solar disturbances at solar offsets greater than 2 solar radii, i.e., at frequencies below 30 MHz. The LORE can be complimentary to the planned Indian solar mission, “Aditya-L1” and its other payloads as well as synergistic to ground-based interplanetary scintillation (IPS) observations, which are routinely carried out by the Ooty Radio Telescope. We discuss the baseline design and technical details of the proposed LORE and its particular suitability for providing measurements on the detailed time and frequency structure of fast drifting type-III and slow drifting type-II radio bursts with unprecedented time and frequency resolutions. We also brief the gonio-polarimetry, which is possible with better-designed antennas and state-of-the-art electronics, employing FPGAs and an intelligent data management system. These would enable us to make a wide range of studies, such as nonlinear plasma processes in the Sun-Earth distance, in-situ radio emission from coronal mass ejections (CMEs), interplanetary CME driven shocks, nature of ICMEs driving decelerating IP shocks and space weather effects of solar wind interaction regions.

  2. A Medley of Radio Winners.

    ERIC Educational Resources Information Center

    Raley, Nancy

    1984-01-01

    The potential for college use and development of radio stations is explored, and innovative and effective ideas from colleges' current efforts are presented. Topics covered include news services, phone-in features, student staff, college program highlights, foreign language programs, paid advertising, and public service announcements. (MSE)

  3. A repeating fast radio burst

    NASA Astrophysics Data System (ADS)

    Spitler, L. G.; Scholz, P.; Hessels, J. W. T.; Bogdanov, S.; Brazier, A.; Camilo, F.; Chatterjee, S.; Cordes, J. M.; Crawford, F.; Deneva, J.; Ferdman, R. D.; Freire, P. C. C.; Kaspi, V. M.; Lazarus, P.; Lynch, R.; Madsen, E. C.; McLaughlin, M. A.; Patel, C.; Ransom, S. M.; Seymour, A.; Stairs, I. H.; Stappers, B. W.; van Leeuwen, J.; Zhu, W. W.

    2016-03-01

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  4. Workplace Training at SBS Radio.

    ERIC Educational Resources Information Center

    Simons, Lynette

    2001-01-01

    Notes that at Australia's Special Broadcasting Services Radio, workplace training is an essential requirement for on-air staff but a degree in journalism or communications is an enormous advantage. Describes several in-house accredited competency-based modules in journalism and broadcasting. (RS)

  5. Counselor Effectiveness Through Radio Communication.

    ERIC Educational Resources Information Center

    Tentoni, Stuart C.

    This study determined the effectiveness of the use of radio as a means of providing immediate feedback on student counselors in a practicum setting. Using a non-equivalent group experimental design, 10 experimental subjects were compared to 10 control subjects with respect to counselor effectiveness. The experimental subjects were given immediate…

  6. Digital Audio Radio Field Tests

    NASA Technical Reports Server (NTRS)

    Hollansworth, James E.

    1997-01-01

    Radio history continues to be made at the NASA Lewis Research Center with the beginning of phase two of Digital Audio Radio testing conducted by the Consumer Electronic Manufacturers Association (a sector of the Electronic Industries Association and the National Radio Systems Committee) and cosponsored by the Electronic Industries Association and the National Association of Broadcasters. The bulk of the field testing of the four systems should be complete by the end of October 1996, with results available soon thereafter. Lewis hosted phase one of the testing process, which included laboratory testing of seven proposed digital audio radio systems and modes (see the following table). Two of the proposed systems operate in two modes, thus making a total of nine systems for testing. These nine systems are divided into the following types of transmission: in-band on channel (IBOC), in-band adjacent channel (IBAC), and new bands - the L-band (1452 to 1492 MHz) and the S-band (2310 to 2360 MHz).

  7. A repeating fast radio burst.

    PubMed

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  8. Dictionary of Radio and Television.

    ERIC Educational Resources Information Center

    Pannett, W. E.

    This dictionary presents definitions of both the well-established terms and many new ones that have come into use with the advances that have taken place in the fields of radio and television. In many cases extended definitions are given in order to describe briefly elementary principles and circuits, while newer and more complex devices and…

  9. International Radio Broadcasting: Who Listens?

    ERIC Educational Resources Information Center

    Browne, Donald R.

    It is difficult to obtain reliable data on the nature of the audience for international broadcast programs in Asia (e.g., those beamed by the Voice of America or Radio Japan). However, analysis of listener mail and some survey research have provided a fairly clear profile of the audience: young (ages 15-34), well educated, urban, male (but with a…

  10. Antarctic radio Askaryan neutrino telescopes

    NASA Astrophysics Data System (ADS)

    Connolly, Amy

    2012-03-01

    There are strong motivations for a detectable flux of ultra-high energy (UHE) cosmic neutrinos above 10^17-18 eV. Neutrinos in this regime are expected from interactions between the highest energy cosmic rays and cosmic microwave background photons, and can also originate from the UHE sources themselves. Radio Cerenkov technique is the most promising technique for instrumenting a detection volume large enough to detect the low expected fluxes. The RICE experiment pioneered the radio Cerenkov technique with antennas deployed along strings of the AMANDA experiment deep in the South Pole ice. New radio arrays being deployed in the Antarctic ice are designed to measure dozens of these unique cosmic messengers to exploit the rich particle physics and astrophysical information that they carry. I will discuss the status and results from initial deployments of the Askaryan Radio Array (ARA) near the South Pole, and the ARIANNA array on the Ross Ice Shelf. I will also describe how these experiments could measure neutrino-nucleon cross sections at energies that exceed those probed by the LHC.

  11. Epsiodic Activity in Radio Galaxies

    SciTech Connect

    Saikia, D.J.; Konar, C.; Jamrozy, M.; Machalski, J.; Gupta, Neeraj; Stawarz, L.; Mack, K.-H.; Siemiginowska, A.; /Harvard-Smithsonian Ctr. Astrophys.

    2007-10-15

    One of the interesting issues in our understanding of active galactic nuclei is the duration of their active phase and whether such activity is episodic. In this paper we summarize our recent results on episodic activity in radio galaxies obtained with the GMRT and the VLA.

  12. 47 CFR 90.185 - Multiple licensing of radio transmitting equipment in the mobile radio service.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Multiple licensing of radio transmitting equipment in the mobile radio service. 90.185 Section 90.185 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES...

  13. 47 CFR 90.185 - Multiple licensing of radio transmitting equipment in the mobile radio service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Multiple licensing of radio transmitting equipment in the mobile radio service. 90.185 Section 90.185 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES...

  14. 47 CFR 90.185 - Multiple licensing of radio transmitting equipment in the mobile radio service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Multiple licensing of radio transmitting equipment in the mobile radio service. 90.185 Section 90.185 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES...

  15. 47 CFR 90.185 - Multiple licensing of radio transmitting equipment in the mobile radio service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Multiple licensing of radio transmitting equipment in the mobile radio service. 90.185 Section 90.185 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES...

  16. 47 CFR 90.185 - Multiple licensing of radio transmitting equipment in the mobile radio service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Multiple licensing of radio transmitting equipment in the mobile radio service. 90.185 Section 90.185 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES...

  17. 33 CFR 401.63 - Radio procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Radio procedures. 401.63 Section 401.63 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Radio Communications § 401.63 Radio procedures....

  18. 33 CFR 401.63 - Radio procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Radio procedures. 401.63 Section 401.63 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Radio Communications § 401.63 Radio procedures....

  19. 47 CFR 32.2231 - Radio systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Radio systems. 32.2231 Section 32.2231... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a) This account shall include the original cost of ownership of radio transmitters and receivers....

  20. 33 CFR 401.63 - Radio procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Radio procedures. 401.63 Section 401.63 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Radio Communications § 401.63 Radio procedures....

  1. 33 CFR 401.63 - Radio procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Radio procedures. 401.63 Section 401.63 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Radio Communications § 401.63 Radio procedures....

  2. 14 CFR 121.345 - Radio equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Radio equipment. 121.345 Section 121.345..., FLAG, AND SUPPLEMENTAL OPERATIONS Instrument and Equipment Requirements § 121.345 Radio equipment. (a) No person may operate an airplane unless it is equipped with radio equipment required for the kind...

  3. 46 CFR 169.715 - Radio.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Radio. 169.715 Section 169.715 Shipping COAST GUARD..., Miscellaneous Systems, and Equipment § 169.715 Radio. (a) Radiotelegraph and radiotelephone installations are... Regulations, part 83. (b) A valid certificate issued by the FCC is evidence that the radio installation is...

  4. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  5. 46 CFR 129.395 - Radio installations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Radio installations. 129.395 Section 129.395 Shipping... INSTALLATIONS Power Sources and Distribution Systems § 129.395 Radio installations. A separate circuit, with overcurrent protection at the switchboard, must be provided for at least one radio installation....

  6. 46 CFR 169.715 - Radio.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Radio. 169.715 Section 169.715 Shipping COAST GUARD..., Miscellaneous Systems, and Equipment § 169.715 Radio. (a) Radiotelegraph and radiotelephone installations are... Regulations, part 83. (b) A valid certificate issued by the FCC is evidence that the radio installation is...

  7. 14 CFR 121.345 - Radio equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Radio equipment. 121.345 Section 121.345..., FLAG, AND SUPPLEMENTAL OPERATIONS Instrument and Equipment Requirements § 121.345 Radio equipment. (a) No person may operate an airplane unless it is equipped with radio equipment required for the kind...

  8. 46 CFR 129.395 - Radio installations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Radio installations. 129.395 Section 129.395 Shipping... INSTALLATIONS Power Sources and Distribution Systems § 129.395 Radio installations. A separate circuit, with overcurrent protection at the switchboard, must be provided for at least one radio installation....

  9. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  10. 47 CFR 32.2231 - Radio systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Radio systems. 32.2231 Section 32.2231... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a) This account shall include the original cost of ownership of radio transmitters and receivers....

  11. 46 CFR 169.715 - Radio.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Radio. 169.715 Section 169.715 Shipping COAST GUARD..., Miscellaneous Systems, and Equipment § 169.715 Radio. (a) Radiotelegraph and radiotelephone installations are... Regulations, part 83. (b) A valid certificate issued by the FCC is evidence that the radio installation is...

  12. 78 FR 37474 - Commercial Radio Operators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-21

    ... COMMISSION 47 CFR Part 13 Commercial Radio Operators AGENCY: Federal Communications Commission. ACTION: Final... years, the information collection associated with commercial radio licenses, as well as for Commercial Operator License Examination Managers (COLEM(s)) that administer commercial radio operator licenses...

  13. 46 CFR 129.395 - Radio installations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Radio installations. 129.395 Section 129.395 Shipping... INSTALLATIONS Power Sources and Distribution Systems § 129.395 Radio installations. A separate circuit, with overcurrent protection at the switchboard, must be provided for at least one radio installation....

  14. 47 CFR 32.2231 - Radio systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Radio systems. 32.2231 Section 32.2231... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a) This account shall include the original cost of ownership of radio transmitters and receivers....

  15. 14 CFR 121.345 - Radio equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Radio equipment. 121.345 Section 121.345..., FLAG, AND SUPPLEMENTAL OPERATIONS Instrument and Equipment Requirements § 121.345 Radio equipment. (a) No person may operate an airplane unless it is equipped with radio equipment required for the kind...

  16. 46 CFR 169.715 - Radio.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Radio. 169.715 Section 169.715 Shipping COAST GUARD..., Miscellaneous Systems, and Equipment § 169.715 Radio. (a) Radiotelegraph and radiotelephone installations are... Regulations, part 83. (b) A valid certificate issued by the FCC is evidence that the radio installation is...

  17. 47 CFR 32.2231 - Radio systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Radio systems. 32.2231 Section 32.2231... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a) This account shall include the original cost of ownership of radio transmitters and receivers....

  18. 46 CFR 129.395 - Radio installations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Radio installations. 129.395 Section 129.395 Shipping... INSTALLATIONS Power Sources and Distribution Systems § 129.395 Radio installations. A separate circuit, with overcurrent protection at the switchboard, must be provided for at least one radio installation....

  19. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  20. 46 CFR 169.715 - Radio.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Radio. 169.715 Section 169.715 Shipping COAST GUARD..., Miscellaneous Systems, and Equipment § 169.715 Radio. (a) Radiotelegraph and radiotelephone installations are... Regulations, part 83. (b) A valid certificate issued by the FCC is evidence that the radio installation is...

  1. 62. The Return of Educational Radio?

    ERIC Educational Resources Information Center

    Berman, Sally D.

    2008-01-01

    This paper examines one of the traditional technologies of distance education, radio, and presents examples of educational and community radio usage in Asia and Africa. Instead of merely transposing western approaches to distance education in developing countries, it is suggested that the developed world can learn from uses of radio in developing…

  2. 46 CFR 129.395 - Radio installations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Radio installations. 129.395 Section 129.395 Shipping... INSTALLATIONS Power Sources and Distribution Systems § 129.395 Radio installations. A separate circuit, with overcurrent protection at the switchboard, must be provided for at least one radio installation....

  3. 33 CFR 401.63 - Radio procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Radio procedures. 401.63 Section 401.63 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Radio Communications § 401.63 Radio procedures....

  4. 14 CFR 121.345 - Radio equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Radio equipment. 121.345 Section 121.345..., FLAG, AND SUPPLEMENTAL OPERATIONS Instrument and Equipment Requirements § 121.345 Radio equipment. (a) No person may operate an airplane unless it is equipped with radio equipment required for the kind...

  5. 14 CFR 121.345 - Radio equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Radio equipment. 121.345 Section 121.345..., FLAG, AND SUPPLEMENTAL OPERATIONS Instrument and Equipment Requirements § 121.345 Radio equipment. (a) No person may operate an airplane unless it is equipped with radio equipment required for the kind...

  6. 78 FR 23150 - Commercial Radio Operators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ... COMMISSION 47 CFR Parts 0, 1, 13, 80 and 87 Commercial Radio Operators AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: This document amends our rules concerning commercial radio operator licenses for maritime and aviation radio stations in order to reduce administrative burdens in the...

  7. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  8. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  9. 47 CFR 32.2231 - Radio systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Radio systems. 32.2231 Section 32.2231... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a) This account shall include the original cost of ownership of radio transmitters and receivers....

  10. A Select Survey of Campus Radio Stations.

    ERIC Educational Resources Information Center

    Drake, H.

    To ascertain the continued need for a campus radio station at 10 watts and to justify a subsequent increase in power, the student radio station at Auburn University (Alabama) conducted surveys of college radio stations, emphasizing facilities in the southeast United States. Some of the findings of the surveys indicated that in the southeast and…

  11. New trends in meteor radio receivers

    NASA Astrophysics Data System (ADS)

    Rault, Jean-Louis

    2014-01-01

    Recent progresses in low cost—but performing—SDR (software defined radio) technology presents a major breakthrough in the domain of meteor radio observations. Their performances are now good enough for meteor work and should therefore encourage newcomers to join the meteor radio community.

  12. Making Waves: Pirate Radio and Popular Music.

    ERIC Educational Resources Information Center

    Jones, Steve

    The history of pirate radio--radio broadcasts offered by unlicensed broadcasters as alternatives to licensed, commercial radio programming--is difficult to trace, both in America and the United Kingdom (UK) since mention of pirate broadcasts of a less-then-thrilling nature are rarely found. Also, until 1927, the U.S. government did not formally…

  13. International Radio Regulations Resulting from WARC 1979.

    ERIC Educational Resources Information Center

    Berrada, Abderrazak

    The main features of international regulations on radio communications of the International Telecommunication Union are summarized and the possible effects on these regulations of the World Administrative Radio Conference of 1979 (WARC-79) are discussed in this paper. It is noted that while the international radio regulations are regarded as…

  14. Packet Radio: An Alternative Way to Connect.

    ERIC Educational Resources Information Center

    Lucas, Larry W.

    1995-01-01

    Explains packet radio as a form of telecomputing in which digital data is transported via radio waves instead of telephone lines or other cabling, and describes how it can be used by students to access the Internet. Highlights include packet bulletin board systems and equipment needed for a packet radio station. (LRW)

  15. Politics and Radio in the 1924 Campaign.

    ERIC Educational Resources Information Center

    Berkman, Dave

    1987-01-01

    Discusses the relation between radio broadcasting and politics in the 1924 presidential campaign, focusing on newspaper and magazine coverage. Notes radio's influence on candidate image, the aspect of censorship, and the use of radio during the campaign and after the election. (MM)

  16. Instructional Radio: So Good but So Neglected.

    ERIC Educational Resources Information Center

    Forsythe, Richard O.

    1979-01-01

    Issues related to the use of radio broadcasting for instructional purposes (such as two-way radio network conferences among doctors) and effectiveness, cost factors, and policy decisions within broadcasting are explored. Suggestions for implementing an instructional program on a school radio station are presented. (PHR)

  17. Voyager planetary radio astronomy studies

    NASA Technical Reports Server (NTRS)

    Staelin, David H.; Eikenberry, Stephen S.

    1993-01-01

    Analysis of nonthermal radio emission data obtained by the Planetary Radio Astronomy (PRA) spectrometers on the Voyager 1 and 2 spacecraft was performed. This PRA data provided unique insights into the radio emission characteristics of the outer planets because of PRA's unique spectral response below the terrestrial ionospheric plasma frequency and its unprecedented proximity to the source. Of those results which were documented or published, this final report surveys only the highlights and cites references for more complete discussions. Unpublished results for Uranus, Neptune, and theoretical Ionian current distributions are presented at greater length. The most important conclusion to be drawn from these observations is that banded spectral emission is common to the radio emission below 1-2 MHz observed from all four Jovian planets. In every case multiple spectral features evolve on time scales of seconds to minutes. To the extent these features drift in frequency, they appear never to cross one another. The Neptunian spectral features appear to drift little or not at all, their evolution consisting principally of waxing and waning. Since other evidence strongly suggests that most or all of this radio emission is occurring near the local magnetospheric electron cyclotron frequency, this implies that this emission preferentially occurs at certain continually changing planetary radii. It remains unknown why certain radii might be favored, unless radial electric field components or other means serve to differentiate radially the magnetospheric plasma density, particle energy vectors, or particle coherence. Calculation of the spatial distribution and intensity of the Io-generated magnetospheric currents are also presented; these currents may be limited principally by wave impedance and local field strengths.

  18. Feasibility study on radio communications using high altitude radio platform in the stratosphere - Applicability to mobile radio and coverage performance

    NASA Astrophysics Data System (ADS)

    Saruwatari, Taiji

    1991-11-01

    It is possible that a platform, powered by microwaves beamed from the earth, carrying radio equipment and flying in the stratosphere, could be used for radio relay such as satellite communications, terrestrial microwave radio relay, land mobile base stations. In the Communication Research Laboratory, feasibility studies were started in 1989 on application of the high altitude radio platform (HARP) to telecommunications and remote sensing. In this paper, features of mobile radio using the HARP, service coverage of the HARP and cellular configurations are described.

  19. Radios in the Classroom: Curriculum Integration and Communication Skills.

    ERIC Educational Resources Information Center

    Ninno, Anton

    2000-01-01

    Describes radio applications for education and summarizes radio activities for elementary and secondary school classrooms. Discusses teaching the history of radio communications; AM-FM radio; international shortwave broadcasts; NOAA (National Oceanic and Atmospheric Administration) weather service broadcasts; scanner radios; and amateur radios.…

  20. The Role of Alternative Programming in College Radio.

    ERIC Educational Resources Information Center

    Sauls, Samuel J.

    College radio is quite often viewed as the true alternative to commercial radio. However, what is alternative radio and how does college radio factor into the ideal? To further understand this concept, this paper focuses on the role of alternative programming in college radio. Areas discussed include alternative radio as a non-mainstream form of…