Science.gov

Sample records for impulse radio communications

  1. Jitter-Robust Orthogonal Hermite Pulses for Ultra-Wideband Impulse Radio Communications

    NASA Astrophysics Data System (ADS)

    de Abreu, Giuseppe Thadeu Freitas; Mitchell, Craig John; Kohno, Ryuji

    2005-12-01

    The design of a class of jitter-robust, Hermite polynomial-based, orthogonal pulses for ultra-wideband impulse radio (UWB-IR) communications systems is presented. A unified and exact closed-form expression of the auto- and cross-correlation functions of Hermite pulses is provided. Under the assumption that jitter values are sufficiently smaller than pulse widths, this formula is used to decompose jitter-shifted pulses over an orthonormal basis of the Hermite space. For any given jitter probability density function (pdf), the decomposition yields an equivalent distribution of [InlineEquation not available: see fulltext.]-by-[InlineEquation not available: see fulltext.] matrices which simplifies the convolutional jitter channel model onto a multiplicative matrix model. The design of jitter-robust orthogonal pulses is then transformed into a generalized eigendecomposition problem whose solution is obtained with a Jacobi-like simultaneous diagonalization algorithm applied over a subset of samples of the channel matrix distribution. Examples of the waveforms obtained with the proposed design and their improved auto- and cross-correlation functions are given. Simulation results are presented, which demonstrate the superior performance of a pulse-shape modulated (PSM-) UWB-IR system using the proposed pulses, over the same system using conventional orthogonal Hermite pulses, in jitter channels with additive white Gaussian noise (AWGN).

  2. 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…

  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. 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…

  5. Talk Radio as Interpersonal Communication.

    ERIC Educational Resources Information Center

    Armstrong, Cameron B.; Rubin, Alan M.

    1989-01-01

    Examines whether talk radio serves different purposes for listeners who phone in, compared to those who do not. Finds that talk radio provides callers with an accessible and nonthreatening alternative to interpersonal communication. (MS)

  6. Distance bounded energy detecting ultra-wideband impulse radio secure protocol.

    PubMed

    Hedin, Daniel S; Kollmann, Daniel T; Gibson, Paul L; Riehle, Timothy H; Seifert, Gregory J

    2014-01-01

    We present a demonstration of a novel protocol for secure transmissions on a Ultra-wideband impulse radio that includes distance bounding. Distance bounding requires radios to be within a certain radius to communicate. This new protocol can be used in body area networks for medical devices where security is imperative. Many current wireless medical devices were not designed with security as a priority including devices that can be life threatening if controlled by a hacker. This protocol provides multiple levels of security including encryption and a distance bounding test to prevent long distance attacks. PMID:25571513

  7. Regulation of Wire and Radio Communication.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    This bulletin reviews early federal regulation of telegraphy, telephone, and radio communications, and the development of the Radio Acts of 1912 and 1927, the Communications Act of 1934, and the Communications Satellite Act of 1962. A large portion of the discussion focuses on the regulatory power and procedures of the Federal Communications…

  8. 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. PMID:22163511

  9. 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

  10. Spread spectrum mobile radio communications

    NASA Astrophysics Data System (ADS)

    Gupta, S. C.; Soliman, S. S.

    1987-02-01

    This report is made up of two parts. In the first part we present additional results on the performance of random access protocols for mobile packet radio networks. The effect of three different types of diversity reception in Nakagami fading environment on the channel throughput and the average packet delay of nonpersistent carrier sense multiple access (NPCSMA) protocol is considered. Expressions for the probability of packet error with diversity receptions are newly obtained for both independent and correlated diversity branches. A noncoherent frequency shift keying modulation scheme is assumed. In the second part a comprehensive study of the problem of synchronization over fading dispersive channels is presented. Synchronization is a fundamental problem in digital communications as used in mobile radio. In the first chapter, we consider a simple binary detection problem. The effect of receiver mismatch is investigated. A closed form expression for the probability of false alarm and probability of detection are given, also a set of curves are provided to demonstrate the amount of degradation for under-spread channels with some special scattering.

  11. 49 CFR 220.45 - Radio communication shall be complete.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Radio communication shall be complete. 220.45... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.45 Radio communication shall be complete. Any radio communication which is not fully understood...

  12. 49 CFR 220.45 - Radio communication shall be complete.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Radio communication shall be complete. 220.45... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.45 Radio communication shall be complete. Any radio communication which is not fully understood...

  13. 49 CFR 220.45 - Radio communication shall be complete.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Radio communication shall be complete. 220.45... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.45 Radio communication shall be complete. Any radio communication which is not fully understood...

  14. 49 CFR 220.45 - Radio communication shall be complete.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communication shall be complete. 220.45... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.45 Radio communication shall be complete. Any radio communication which is not fully understood...

  15. 49 CFR 220.45 - Radio communication shall be complete.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Radio communication shall be complete. 220.45... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.45 Radio communication shall be complete. Any radio communication which is not fully understood...

  16. 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.

  17. Association of Coronal Mass Ejections and Type II Radio Bursts with Impulsive Solar Energetic Particle Events

    NASA Astrophysics Data System (ADS)

    Yashiro, S.; Gopalswamy, N.; Cliver, E. W.; Reames, D. V.; Kaiser, M. L.; Howard, R. A.

    2004-12-01

    We report the association of impulsive solar energetic particle (SEP) events with coronal mass ejections (CMEs) and metric type II radio bursts. We identified 38 impulsive SEP events using the WIND/EPACT instrument and their CME association was investigated using white light data from SOHO/LASCO. We found that (1) at least ˜ 28--39 % of impulsive SEP events were associated with CMEs, (2) only 8--13 % were associated with metric type II radio bursts. The statistical properties of the associated CMEs were investigated and compared with those of general CMEs and CMEs associated with large gradual SEP events. The CMEs associated with impulsive SEP events were significantly slower (median speed of 613 kmps) and narrower (49 deg) than those of CMEs associated with large gradual SEP events (1336 kmps, 360 deg), but faster than the general CMEs (408 kmps).

  18. Radio communications with extra-terrestrial civilizations

    NASA Technical Reports Server (NTRS)

    Kotelnikov, V. A.

    1974-01-01

    Communications between civilizations within our galaxy at the present level of radio engineering is possible, although civilizations must begin to search for each other to achieve this. If an extra-terrestrial civilization possessing a technology at our level wishes to make itself known and will transmit special radio signals to do this, then it can be picked up by us at a distance of several hundreds of light years using already existing radio telescopes and specially built radio receivers. If it wishes, this civilization can also send us information without awaiting our answer.

  19. 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…

  20. 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.…

  1. 49 CFR 220.51 - Radio communications and signal indications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Radio communications and signal indications. 220... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.51 Radio communications and signal indications. (a) No information may be...

  2. 49 CFR 220.51 - Radio communications and signal indications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Radio communications and signal indications. 220... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.51 Radio communications and signal indications. (a) No information may be...

  3. 49 CFR 220.51 - Radio communications and signal indications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Radio communications and signal indications. 220... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.51 Radio communications and signal indications. (a) No information may be...

  4. 49 CFR 220.51 - Radio communications and signal indications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communications and signal indications. 220... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.51 Radio communications and signal indications. (a) No information may be...

  5. 49 CFR 220.51 - Radio communications and signal indications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Radio communications and signal indications. 220... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.51 Radio communications and signal indications. (a) No information may be...

  6. Spanish Basic Course: Radio Communications Procedures, USAF.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This guide to radio communication procedures is offered in Spanish and English as a means of securing a closer working relationship among United States Air Force personnel and Latin American aviators and technicians. Eight dialogues concerning routine flight procedures and aerospace technology are included. It is suggested that two rated students…

  7. Evolution of a radio communication relay system

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoa G.; Pezeshkian, Narek; Hart, Abraham; Burmeister, Aaron; Holz, Kevin; Neff, Joseph; Roth, Leif

    2013-05-01

    Providing long-distance non-line-of-sight control for unmanned ground robots has long been recognized as a problem, considering the nature of the required high-bandwidth radio links. In the early 2000s, the DARPA Mobile Autonomous Robot Software (MARS) program funded the Space and Naval Warfare Systems Center (SSC) Pacific to demonstrate a capability for autonomous mobile communication relaying on a number of Pioneer laboratory robots. This effort also resulted in the development of ad hoc networking radios and software that were later leveraged in the development of a more practical and logistically simpler system, the Automatically Deployed Communication Relays (ADCR). Funded by the Joint Ground Robotics Enterprise and internally by SSC Pacific, several generations of ADCR systems introduced increasingly more capable hardware and software for automatic maintenance of communication links through deployment of static relay nodes from mobile robots. This capability was finally tapped in 2010 to fulfill an urgent need from theater. 243 kits of ruggedized, robot-deployable communication relays were produced and sent to Afghanistan to extend the range of EOD and tactical ground robots in 2012. This paper provides a summary of the evolution of the radio relay technology at SSC Pacific, and then focuses on the latest two stages, the Manually-Deployed Communication Relays and the latest effort to automate the deployment of these ruggedized and fielded relay nodes.

  8. Radio occultation constellation deployment via impulses along the geomagnetic field

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, Michael Yu.; Trofimov, Sergey P.; Chang, Hao-Chi

    2013-01-01

    The problem of radio occultation (RO) constellation deployment is examined. Of particular interest here is to study the feasibility of using passively stabilized small satellites. We consider a pair of satellites supplied with a passive magnetic attitude control system. The capsule containing two satellites is launched into a parking orbit and stabilized along the geomagnetic field direction. Then the satellites are pushed apart by a separation spring at some point of orbit. If necessary for braking, one or two thrusters may be placed along the stabilized axis of each satellite. Optimization of the separation point and velocity along with the ΔV required for possible braking thrust is carried out in accordance with some specific demands of RO missions. Atmospheric drag and Earth oblateness are taken into account as perturbations. It is shown that, depending on a mission scenario, the separation with either one braking thrust or no thrusts at all is preferable.

  9. Satellite observations of transient radio impulses from thunderstorms

    SciTech Connect

    Argo, P.E.; Kirkland, M.; Jacobson, A.; Massey, R.; Suszynsky, D.; Eack, K.; Fitzgerald, T.J.; Smith, D.

    1999-06-01

    Transient radio emissions from thunderstorms detected by satellites were first reported in 1995. The nature and source of these emissions remained a mystery until the launch of the FORTE satellite in 1997. FORTE, with its more sophisticated triggering and larger memory capacity showed that these emissions were connected to major thunderstorm systems. The analysis reported here, connecting FORTE RF events with ground based lightning location data from the National Lightning Detection Network (NLDN), shows that localized regions within thunderstorms are responsible for the creation of the satellite detected rf signals. These regions are connected with the areas of strong radar returns from the NEXRAD Doppler radar system, indicating that they are from regions of intense convection. The authors will also show data from several storms detected in the extended Caribbean, in which the height profile of the source regions can be determined. Although as a single low earth orbit satellite FORTE cannot provide global coverage of thunderstorm/lightning events, follow-on satellite constellations should be able to provide detailed information on global lightning in near real-time.

  10. Radio Emissions Precursors of Impulsive Phase of Solar Flares Recorded by CALLISTO-BR

    NASA Astrophysics Data System (ADS)

    Fernandes, Francisco; Cunha-Silva, Rafael; Galdino, Marcela; Sodré, Zuleika

    2016-07-01

    A solar flare consists in an eruptive process and involves a sudden release of energy generated by processes carried on from instabilities in the magnetic configuration at solar atmosphere, generating emissions at different wavelengths. Usually, the pre-flare phase presents an increasing of soft X-ray, ultraviolet and radio emissions. In this work, we present a survey of solar radio emission recorded in metric wavelengths (45 - 250 MHz) by CALLISTO-BR spectrograph, belong to the e-Callisto network, associated with pre-flare phase of solar X-rays flares. A sample of 281 radio emissions was analyzed, and 120 were identified as precursor emissions of X-rays flares. The main results of the statistics can be summarized as: (a) 55% of the precursor radio emissions start less than 60 minutes before the beginning of the associated X-ray flare and about 20% start less than 20 minutes before the X-ray emission; (b) 27% of flares with precursor emissions are classified as B class, 61% of C class, and less than 22% of M class. No precursors radio emissions were associated with X class flare; (c) about 42% of radio precursor emissions are of type III bursts and 33% have complex morphology, as drifting pulsating structures. Analysis of global emission trends recorded during the precursor phase of the C4.8 flare of February 15, 2011 (14:32-14:51 UT) is also presented. The occurrence of radio emission during the pre-impulsive phase of a solar flare suggests the presence of plasma turbulence in the active region, since during the impulsive phase, when the energy is released, occur the heating of the plasma and increasing of soft X-ray emission as identified in the event analyzed. The results are presented and discussed.

  11. Radio Science from an Optical Communications Signal

    NASA Technical Reports Server (NTRS)

    Moision, Bruce; Asmar, Sami; Oudrhiri, Kamal

    2013-01-01

    NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable precision in estimating range, doppler, and received signal intensity of an non-coherent optical link (the current state-of-the-art for a deep-space link). We provide a joint estimation algorithm with performance close to the bound. We draw comparisons to estimates based on a coherent radio frequency signal, illustrating that large gains in either precision or observation time are possible with an optical link.

  12. Software-Defined Radio for Space-to-Space Communications

    NASA Technical Reports Server (NTRS)

    Fisher, Ken; Jih, Cindy; Moore, Michael S.; Price, Jeremy C.; Abbott, Ben A.; Fritz, Justin A.

    2011-01-01

    A paper describes the Space- to-Space Communications System (SSCS) Software- Defined Radio (SDR) research project to determine the most appropriate method for creating flexible and reconfigurable radios to implement wireless communications channels for space vehicles so that fewer radios are required, and commonality in hardware and software architecture can be leveraged for future missions. The ability to reconfigure the SDR through software enables one radio platform to be reconfigured to interoperate with many different waveforms. This means a reduction in the number of physical radio platforms necessary to support a space mission s communication requirements, thus decreasing the total size, weight, and power needed for a mission.

  13. Hybrid optical radio frequency airborne communications

    NASA Astrophysics Data System (ADS)

    Bagley, Zachary C.; Hughes, David H.; Juarez, Juan C.; Kolodzy, Paul; Martin, Todd; Northcott, Malcolm; Pike, H. Alan; Plasson, Ned D.; Stadler, Brian; Stotts, Larry B.; Young, David W.

    2012-05-01

    Optical RF Communications Adjunct Program flight test results provide validation of the theoretical models and hybrid optical radio frequency (RF) airborne system concepts developed by the Defense Advanced Research Projects Agency and the U.S. Air Force Research Laboratory. Theoretical models of the free-space optical communications (FSOC), RF, and network components accurately predict the flight test results under a wide range of day and night operating conditions. The FSOC system, including the adaptive optics and optical modem, can operate under high turbulence conditions. The RF and network mechanisms of Layer 2 retransmission and failover provide increased reliability, reducing end-to-end packet error rates. Overall the test results show that stable, long-range FSOC is possible and practical for near-term operations.

  14. Rhetorical Perspectives in Radio Communications: The Speaker and the Loudspeaker.

    ERIC Educational Resources Information Center

    Godfrey, Donald G.

    Radio rhetoric is set apart from traditional rhetoric by the efficacy it commands. This study focuses on rhetorical perspective in radio communication, noting 10 identifiable aspects of radio rhetoric noteworthy in undertaking rhetorical criticism: (1) the pressures of federal regulations which require balanced presentation affect preparation; (2)…

  15. Experimental radio frequency link for Ka-band communications applications

    NASA Technical Reports Server (NTRS)

    Fujikawa, Gene; Conray, Martin J.; Saunders, Alan L.; Pope, Dale E.

    1988-01-01

    An experimental radio frequency link has been demonstrated to provide two-way communication between a remote user ground terminal and a ground-based Ka-band transponder. Bit-error-rate performance and radio frequency characteristics of the communication link were investigated.

  16. Radio Quiet Zones (RQZ) - Working with national communication administrations

    NASA Astrophysics Data System (ADS)

    Tzioumis, Anastasios

    Radio Astronomy detects extremely faint radio signals from space, and hence is very susceptible to Radio Frequency Interference (RFI) from other radio communication services. Although radio astronomy has been allocated some radio bands by the International Telecommunications Union (ITU), cosmic radio emissions occur over the whole of the electromagnetic spectrum. Thus, there is a need for radio telescopes to operate over very wide radio bands and avoid RFI. Radio Quiet Zones (RQZ) in various forms have been implemented around many radio astronomy observatories, to minimise the impact of RFI on radio astronomy observations by coordinating with nearby radiocommunication services. The history and characteristics of such RQZ around the world will be reviewed, with emphasis on recent experience. For the next generation radio astronomy telescopes such as the Square Kilometre Array (SKA), it will be of critical importance to minimise RFI over the whole operating frequency range 200 MHz - 25 GHz. Progress towards establishing strict RQZ for the SKA will be reviewed. The main experience and lesson learned is that it is critical to work closely with national communication administrations. Work on RQZ in international bodies and the implications for radio sciences will also be discussed.

  17. Solar Influence on Ionosphere and Radio Communications

    NASA Astrophysics Data System (ADS)

    Reddy, B. M.

    2006-11-01

    When we are discussing solar influence on Ionosphere, it will be helpful to remember that less than one-thousandth of the solar energy being intercepted by the planet Earth is responsible for its production and dynamics. This includes the solar wind energy intercepted by a much larger magnetosphere. But it is this small fraction of energy (in the X-rays, EUV and solar wind) that undergoes violent fluctuations during the course of a solar cycle and during such solar events as flares and Coronal Mass Ejections (CMEs).The consequences of these events are now generically dubbed as “Space Weather”. The problems created by extreme space weather events encompass a wide variety of applications of human interest. These include difficulties to satellite operations, ionosphere-reflected H.F Communications, GPS operations and even power grids and gas pipelines. I will restrict my presentation to H.F communications and to certain science elements such as anomalous plasma temperature variations measured by satellites. Particular attention will be given to increases in electron temperatures during magnetic storms in the night time when there is no photo-electron heat input. As this has a bearing on the present theory of electron thermal conduction associated with increase in neutral densities during storms, a detailed analysis will be presented using satellite data. Also the presentation will include examples of H.F communication failures especially at night time, contrary to what is expected at low latitudes. This has serious implications to the communication scenario in India in view of the high Atmospheric Radio Noise at the lower bands of the H.F. Spectrum.

  18. Localized radio frequency communication using asynchronous transfer mode protocol

    DOEpatents

    Witzke, Edward L.; Robertson, Perry J.; Pierson, Lyndon G.

    2007-08-14

    A localized wireless communication system for communication between a plurality of circuit boards, and between electronic components on the circuit boards. Transceivers are located on each circuit board and electronic component. The transceivers communicate with one another over spread spectrum radio frequencies. An asynchronous transfer mode protocol controls communication flow with asynchronous transfer mode switches located on the circuit boards.

  19. Suppression of radio frequency inteference (RFI) for synchronous impulse reconstruction ultra-wideband radar

    NASA Astrophysics Data System (ADS)

    Nguyen, Lam; Soumekh, Mehrdad

    2005-05-01

    This paper is concerned with the issues associated with the suppression of radio frequency interference (RFI) for a synchronous impulse reconstruction (SIRE) ultra-wideband (UWB) synthetic aperture radar (SAR) that is currently being designed and built at the Army Research Laboratory. In this effort, we are developing the next version of the UWB radar that can employ inexpensive A/D converters to digitize wideband signals using the equivalent time sampling technique. In this presentation, we provide an analytical model for the signature of the RFI sources that are measured via an equivalent time sampling scheme. This formulation reveals spectral as well as temporal properties of the measured RFI signals that would aid a user in developing sniff (passive) data collection strategies for constructing adaptive digital signal processing methods for suppressing RFI sources.

  20. 80. Survivable lowfrequency communications system receiver, teletypewriter set, radio, teleprinter, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    80. Survivable low-frequency communications system receiver, teletypewriter set, radio, teleprinter, south side - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

  1. Inflatable Reflector For Solar Power And Radio Communication

    NASA Technical Reports Server (NTRS)

    Sercel, Joel; Gilchriest, Carl; Ewell, Rich; Herman, Martin; Rascoe, Daniel L.; Nesmith, Bill J.

    1995-01-01

    Report proposes installation of lightweight inflatable reflector structure aboard spacecraft required to both derive power from sunlight and communicate with Earth by radio when apparent position of Earth is at manageably small angle from line of sight to Sun. Structure contains large-aperture paraboloidal reflector aimed toward Sun and concentrates sunlight onto photovoltaic power converter and acts as main reflector of spacecraft radio-communication system.

  2. Performance evaluation of cognitive radio in advanced metering infrastructure communication

    NASA Astrophysics Data System (ADS)

    Hiew, Yik-Kuan; Mohd Aripin, Norazizah; Din, Norashidah Md

    2016-03-01

    Smart grid is an intelligent electricity grid system. A reliable two-way communication system is required to transmit both critical and non-critical smart grid data. However, it is difficult to locate a huge chunk of dedicated spectrum for smart grid communications. Hence, cognitive radio based communication is applied. Cognitive radio allows smart grid users to access licensed spectrums opportunistically with the constraint of not causing harmful interference to licensed users. In this paper, a cognitive radio based smart grid communication framework is proposed. Smart grid framework consists of Home Area Network (HAN) and Advanced Metering Infrastructure (AMI), while AMI is made up of Neighborhood Area Network (NAN) and Wide Area Network (WAN). In this paper, the authors only report the findings for AMI communication. AMI is smart grid domain that comprises smart meters, data aggregator unit, and billing center. Meter data are collected by smart meters and transmitted to data aggregator unit by using cognitive 802.11 technique; data aggregator unit then relays the data to billing center using cognitive WiMAX and TV white space. The performance of cognitive radio in AMI communication is investigated using Network Simulator 2. Simulation results show that cognitive radio improves the latency and throughput performances of AMI. Besides, cognitive radio also improves spectrum utilization efficiency of WiMAX band from 5.92% to 9.24% and duty cycle of TV band from 6.6% to 10.77%.

  3. Radio Communication Systems for the Disabled

    ERIC Educational Resources Information Center

    Kent, Herbert; Lesieur, Russel C.

    1978-01-01

    Presented are pertinent essentials concerning the use of Citizens Radio Service, particularly class D, and the Amateur Radio Service for the physically disabled. Prohibited and permitted uses are described in detail, and the Ten Code and some fundamental concepts are discussed. Eligibility and filing directions are also included. (BM)

  4. The Fascinating World of Radio Communications.

    ERIC Educational Resources Information Center

    Green, Wayne, Ed.

    Intended mainly for the amateur radio operator, or "ham," this book outlines some of the pleasures to be had in amateur radio, including DXing (calling distant stations) and helping in emergencies. The steps in starting out on this hobby, including getting Citizens' Band (CB) gear, a CB license, and a receiver and antenna, are described. Also…

  5. 49 CFR 220.43 - Radio communications consistent with federal regulations and railroad operating rules.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Radio communications consistent with federal... Radio and Wireless Communication Procedures § 220.43 Radio communications consistent with federal regulations and railroad operating rules. Radio communication shall not be used in connection with a...

  6. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  7. 49 CFR 220.43 - Radio communications consistent with federal regulations and railroad operating rules.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communications consistent with federal... Radio and Wireless Communication Procedures § 220.43 Radio communications consistent with federal regulations and railroad operating rules. Radio communication shall not be used in connection with a...

  8. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  9. 49 CFR 220.43 - Radio communications consistent with federal regulations and railroad operating rules.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Radio communications consistent with federal... Radio and Wireless Communication Procedures § 220.43 Radio communications consistent with federal regulations and railroad operating rules. Radio communication shall not be used in connection with a...

  10. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  11. 49 CFR 220.43 - Radio communications consistent with federal regulations and railroad operating rules.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Radio communications consistent with federal... Radio and Wireless Communication Procedures § 220.43 Radio communications consistent with federal regulations and railroad operating rules. Radio communication shall not be used in connection with a...

  12. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  13. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  14. Impulsive interference in communication channels and its mitigation by SPART and other nonlinear filters

    NASA Astrophysics Data System (ADS)

    Nikitin, Alexei V.; Epard, Marc; Lancaster, John B.; Lutes, Robert L.; Shumaker, Eric A.

    2012-12-01

    A strong digital communication transmitter in close physical proximity to a receiver of a weak signal can noticeably interfere with the latter even when the respective channels are tens or hundreds of megahertz apart. When time domain observations are made in the signal chain of the receiver between the first mixer and the baseband, this interference is likely to appear impulsive. The impulsive nature of this interference provides an opportunity to reduce its power by nonlinear filtering, improving the quality of the receiver channel. This article describes the mitigation, by a particular nonlinear filter, of the impulsive out-of-band (OOB) interference induced in High Speed Downlink Packet Access (HSDPA) by WiFi transmissions, protocols which coexist in many 3G smartphones and mobile hotspots. Our measurements show a decrease in the maximum error-free bit rate of a 1.95 GHz HSDPA receiver caused by the impulsive interference from an OOB 2.4 GHz WiFi transmission, sometimes down to a small fraction of the rate observed in the absence of the interference. We apply a nonlinear SPART filter to recover a noticeable portion of the lost rate and maintain an error-free connection under much higher levels of the WiFi interference than a receiver that does not contain such a filter. These measurements support our wider investigation of OOB interference resulting from digital modulation, which appears impulsive in a receiver, and its mitigation by nonlinear filters.

  15. Communicating radio astronomy with the public: Another point of view

    NASA Astrophysics Data System (ADS)

    Varano, S.

    2008-06-01

    Radio waves cannot be sensed directly, but they are used in daily life by almost everybody. Even so, the majority of the general public do not even know that celestial bodies emit radio waves. Presenting invisible radiation to a general audience with little or no background knowledge in physics is a difficult task. In addition, much important technology now commonplace in many other scientific fields was pioneered by radio observatories in their efforts to detect and process radio signals from the Universe. Radio astronomy outreach does not have such a well-established background as optical astronomy outreach. In order to make radio astronomy accessible to the public, it is necessary either to add more scientific detail or to find a different way of communicating. In this paper we present examples from our work at the Visitor Centre "Marcello Ceccarelli", which is part of the Medicina Radio Observatory, operated by the Institute of Radio Astronomy (IRA) in Bologna, which in turn is part of the National Institute for Astrophysics (INAF).

  16. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Radio communication used in shoving, backing or... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or...

  17. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communication used in shoving, backing or... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or...

  18. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Radio communication used in shoving, backing or... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or...

  19. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Radio communication used in shoving, backing or... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or...

  20. Technology Evaluation of Programmable Communicating Thermostats with Radio Broadcast Data System Communications

    SciTech Connect

    Herter, Karen; Wayland, Seth

    2008-10-31

    Programmable Communicating Thermostats are thermostats that can be programmed by the user to respond to signals indicating a grid-level system emergency or pricing event. The California Energy Commission is considering standards that would include a requirement for Programmable Communicating Thermostats in residential and small commercial applications. The current specification for Programmable Communicating Thermostats requires Radio Data System communications to Programmable Communicating Thermostats. This study tested the signal strength and reliability of Radio Data System signals at 40 customer sites within the Sacramento Municipal Utility District, which is serviced by 17 radio stations that already transmit Radio Data System signals. The study also tested the functionality of a commercially available Programmable Communicating Thermostat for compliance with California Energy Commission design standards. Test results demonstrated that Radio Data System is capable of reliably sending price and emergency signals. This study also provides evidence that existing Programmable Communicating Thermostats, on receiving a Radio Data System pricing or event signal, are capable of automatically increasing set points to a customer-determined or utility-determined level, thus providing air-conditioning demand response within seconds or just a few (less than 5) minutes.

  1. Radio for Formal Education and for Development Communication.

    ERIC Educational Resources Information Center

    Development Communication Report, 1978

    1978-01-01

    The keynote article in this issue describes some empirically demonstrated beneficial functions of radio in development communications: (1) it improves the quality and relevance of education; (2) it keeps educational costs down; (3) it broadens access to education; and (4) it extends the impact of time, money, and effort outside the formal…

  2. Integrated Radio and Optical Communication (iROC)

    NASA Technical Reports Server (NTRS)

    Raible, Daniel; Romanofsky, Robert; Pease, Gary; Kacpura, Thomas

    2016-01-01

    This is an overview of the Integrated Radio and Optical Communication (iROC) Project for Space Communication and Navigation Industry Days. The Goal is to develop and demonstrate new, high payoff space technologies that will promote mission utilization of optical communications, thereby expanding the capabilities of NASA's exploration, science, and discovery missions. This is an overview that combines the paramount features of select deep space RF and optical communications elements into an integrated system, scalable from deep space to near earth. It will realize Ka-band RF and 1550 nanometer optical capability. The approach is to prototype and demonstrate performance of key components to increase to TRL-5, leading to integrated hybrid communications system demonstration to increase to TRL-5, leading to integrated hybrid communications system demonstration.

  3. MicrobeWorld Radio and Communications Initiative

    SciTech Connect

    Barbara Hyde

    2006-11-22

    MicrobeWorld is a 90-second feature broadcast daily on more than 90 public radio stations and available from several sources as a podcast, including www.microbeworld.org. The feature has a strong focus on the use and adapatbility of microbes as alternative sources of energy, in bioremediation, their role in climate, and especially the many benefits and scientific advances that have resulting from decoding microbial genomes. These audio features are permanantly archived on an educational outreach site, microbeworld.org, where they are linked to the National Science Education Standards. They are also being used by instructors at all levels to introduce students to the multiple roles and potential of microbes, including a pilot curriculum program for middle-school students in New York.

  4. 49 CFR 220.21 - Railroad operating rules; radio communications; recordkeeping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... meaning given these terms in 49 CFR Part 1201. ... 49 Transportation 4 2013-10-01 2013-10-01 false Railroad operating rules; radio communications...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and...

  5. 49 CFR 220.21 - Railroad operating rules; radio communications; recordkeeping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... meaning given these terms in 49 CFR Part 1201. ... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad operating rules; radio communications...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and...

  6. 49 CFR 220.21 - Railroad operating rules; radio communications; recordkeeping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... meaning given these terms in 49 CFR Part 1201. ... 49 Transportation 4 2014-10-01 2014-10-01 false Railroad operating rules; radio communications...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and...

  7. 49 CFR 220.21 - Railroad operating rules; radio communications; recordkeeping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... meaning given these terms in 49 CFR Part 1201. ... 49 Transportation 4 2012-10-01 2012-10-01 false Railroad operating rules; radio communications...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and...

  8. 49 CFR 220.21 - Railroad operating rules; radio communications; recordkeeping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... meaning given these terms in 49 CFR Part 1201. ... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad operating rules; radio communications...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and...

  9. Electromagnetic compatibility fundamentals applied to spacecraft radio communication systems

    NASA Technical Reports Server (NTRS)

    Haber, F.; Celebiler, M.; Weil-Malherbe, C.

    1971-01-01

    A design guide for minimizing electromagnetic interference in aerospace communication equipment for ground stations is presented. Specifically treated are the mechanisms of generating unwanted radio emissions that may affect station operations as well as other communications services, the mechanisms by which sensitive receivers become susceptible to interference, means for reducing interference, standard methods of measurement, and the problems of site selection. The sources of interference are viewed primarily as originating from communications transmitters aboard spacecraft and aircraft, ground transmitters within and outside the ground stations, and other electrical sources on the ground that are not intended to radiate.

  10. Radio propagation for space communications systems

    NASA Technical Reports Server (NTRS)

    Ippolito, L. J.

    1981-01-01

    This paper presents a review of the most recent information on the effects of the earth's atmosphere on space communications systems. Models and techniques used in the prediction of atmospheric effects as influenced by frequency, geography, elevation angle, and type of transmission are discussed. Recent data on performance characteristics obtained from direct measurements on satellite links operating to above 30 GHz are reviewed. Particular emphasis is placed on the effects of precipitation on the earth-space path, including rain attenuation, and rain and ice-particle depolarization. Sky noise, antenna gain degradation, scintillations, and bandwidth coherence are also discussed. The impact of the various propagation factors on communications system design criteria is presented. These criteria include link reliability, power margins, noise contributions, modulation and polarization factors, channel crosstalk, error-rate, and bandwidth limitations.

  11. 49 CFR 220.29 - Statement of letters and numbers in radio communications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Statement of letters and numbers in radio...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.29 Statement of letters and numbers in radio communications. (a) If necessary...

  12. 49 CFR 220.29 - Statement of letters and numbers in radio communications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Statement of letters and numbers in radio...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.29 Statement of letters and numbers in radio communications. (a) If necessary...

  13. 49 CFR 220.29 - Statement of letters and numbers in radio communications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Statement of letters and numbers in radio...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.29 Statement of letters and numbers in radio communications. (a) If necessary...

  14. 49 CFR 220.29 - Statement of letters and numbers in radio communications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Statement of letters and numbers in radio...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.29 Statement of letters and numbers in radio communications. (a) If necessary...

  15. Impulsiveness and energetics in solar flares with and without type II radio bursts - A comparison of hard X-ray characteristics for over 2500 solar flares

    NASA Technical Reports Server (NTRS)

    Pearson, Douglas H.; Nelson, Robert; Kojoian, Gabriel; Seal, James

    1989-01-01

    The hard X-ray characteristics of more than 2500 solar flares are used to study the relative size, impulsiveness, and energetics of flares with and without type II radio bursts. A quantitative definition of the hard X-ray impulsiveness is introduced, which may be applied to a large number of events unambiguously. It is found that the flares with type II bursts are generally not significantly larger, more impulsive, or more energetic than those without type II bursts. Also, no evidence is found to suggest a simple classification of the flares as either 'impulsive' or 'gradual'. Because type II bursts are present even in small flares with relatively unimpulsive energy releases, it is concluded that changes in the ambient conditions of the solar atmosphere causing an unusually low Alfven speed may be important in the generation of the shock wave that produces type II radio bursts.

  16. Meteor scatter radio communication at high latitudes

    NASA Astrophysics Data System (ADS)

    Cannon, P. S.; Dickson, A. H.; Armstrong, M. H.

    1985-11-01

    A brief historical and physical description of the meteor burst communications (MBC) technique is given together with a discussion of the advantages of very high frequency MBC, with respect to conventional high frequency communication, when used at high latitudes. A recently deployed high latitude MBC propagation experiment, between Bodo in Norway and Wick in Scotland (UK) is described and some of the early data gathered at frequencies close to 40 MHz and 70 MHz is presented. A theoretical description of the effects of Polarisation Rotation in a linearly polarised MBC system is developed and it is shown that at 40 MHz Polarisation Rotation, due to excess D-region ionization may cause the system performance to differ from its ambient level. Corroborative experimental results, over a temperature latitude path, are presented. Based upon the early high latitude experimental results and on the theoretical calculations, it is suggested that frequencies close to 40 MHz, in common use in atemperate latitude linearly polarised MBC systems, are too low for high latitude operation.

  17. Software Defined Radio Architecture Contributions to Next Generation Space Communications

    NASA Technical Reports Server (NTRS)

    Kacpura, Thomas J.; Eddy, Wesley M.; Smith, Carl R.; Liebetreu, John

    2015-01-01

    systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused.

  18. Modeling Radio Communication Blackout and Blackout Mitigation in Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Kundrapu, Madhusudhan; Loverich, John; Beckwith, Kristian; Stoltz, Peter; Shashurin, Alexey; Keidar, Michael

    2015-05-01

    A procedure for the modeling and analysis of radio communication blackout of hypersonic vehicles is presented. The weakly ionized plasma generated around the surface of a hypersonic reentry vehicle is simulated using full Navier-Stokes equations in multi-species single fluid form. A seven species air chemistry model is used to compute the individual species densities in air including ionization - plasma densities are compared with experiment. The electromagnetic wave's interaction with the plasma layer is modeled using multi-fluid equations for fluid transport and full Maxwell's equations for the electromagnetic fields. The multi-fluid solver is verified for a whistler wave propagating through a slab. First principles radio communication blackout over a hypersonic vehicle is demonstrated along with a simple blackout mitigation scheme using a magnetic window.

  19. Radio frequency communication system utilizing radiating transmission lines

    DOEpatents

    Struven, Warren C.

    1984-01-01

    A radio communication system for use in tunnels, mines, buildings or other shielded locations in which a pair of radiating transmission lines (30), (31) extend through such location in spaced coextensive relation to each other. Each transmission line (30), (31) has at least one unidirectional amplifier (32), (33) interposed therein with the sense of the unidirectional amplifier (32) of one transmission line (30) being opposite to the sense of the unidirectional amplifier (33) of the other transmission line (31). Each of the amplifiers (32), (33) has a gain which is less than the coupling loss between the transmission lines (30), (31). Two or more mobile transceivers (35) in the location served by the system are coupled to the transmission lines (30), (31) by electromagnetic wave propagation in space in order to communicate directly with each other at a given radio frequency within the frequency range of the system.

  20. A wideband propagation simulator for high speed mobile radio communications

    NASA Astrophysics Data System (ADS)

    Busson, P.; Lejannic, J. C.; Elzein, G.; Citerne, J.

    1994-07-01

    Multipath, jamming, listening and detection are the main limitations for mobile radio communications. Spread spectrum techniques, especially frequency hopping, can be used to avoid these problems. Therefore, a wideband simulation for multipath mobile channels appeared the most appropriate evaluation technique. It also gives useful indications for system characteristic improvements. This paper presents the design and realization of a new UHF-VHF propagation simulator, which can be considered as an extended version of Bussgang's one. This frequency hopping simulator (up to 100,000 hops per second) is wideband thus capable to deal with spread spectrum signals. As it generates up to 16 paths, it can be used in almost all mobile radio propagation situations. Moreover, it is also able to simulate high mobile relative speeds up to 2000km/h such as air-air communication systems. This simulator can reproduce, in laboratory, 16 rays Rician or Rayleigh fading channels with a maximum time delay of about 15 ms. At the highest frequency of 1200 MHz, Doppler rates up to 2 kHz can be generated corresponding to vehicle speeds up to 2000 km/h. Let note that the Bussgang simulator was defined for narrowband and fixed radio communications. In both equipments, in-phase and quadrature signals are obtained using two numerical transversal filters. Simulation results were derived in various situations especially in terrestrial urban and suburban environments, where they could be compared with measurements. The main advantage of the simulator lies in its capacity to simulate the high speed and wideband mobile radio communication channels.

  1. Tunnel radio communications system at Stanford Linear Accelerator Center

    SciTech Connect

    Struven, W.C.

    1980-07-01

    A unique single frequency, dual daisy chain tunnel radio communication system has been developed for use in our new Positron-Electron Storage Ring. Communications are possible between portables in the underground ring and between a portable in the ring and all control rooms on the site. The system is designed as a wide band facility and therefore can carry many simplex and duplex transmissions. This system utilizes TV twinlead as a distributed antenna and repeater amplifiers to cover more than 7000 feet of underground tunnel. The design philosophy, tests and initial design are discussed and contrasted with the final implementation of the system. Future uses of the system are discussed.

  2. Networked Operations of Hybrid Radio Optical Communications Satellites

    NASA Technical Reports Server (NTRS)

    Hylton, Alan; Raible, Daniel

    2014-01-01

    In order to address the increasing communications needs of modern equipment in space, and to address the increasing number of objects in space, NASA is demonstrating the potential capability of optical communications for both deep space and near-Earth applications. The Integrated Radio Optical Communications (iROC) is a hybrid communications system that capitalizes on the best of both the optical and RF domains while using each technology to compensate for the other's shortcomings. Specifically, the data rates of the optical links can be higher than their RF counterparts, whereas the RF links have greater link availability. The focus of this paper is twofold: to consider the operations of one or more iROC nodes from a networking point of view, and to suggest specific areas of research to further the field. We consider the utility of Disruption Tolerant Networking (DTN) and the Virtual Mission Operation Center (VMOC) model.

  3. 75 FR 20951 - Amendment of the Commission's Rules Regarding Amateur Radio Service Communications During...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 97 Amendment of the Commission's Rules Regarding Amateur Radio Service Communications During Government Disaster Drills AGENCY: Federal Communications Commission. ACTION: Notice of...

  4. 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. PMID:23381294

  5. Coordination procedure for radio relay and communication satellite services

    NASA Technical Reports Server (NTRS)

    Eckerman, J.

    1973-01-01

    A global rain rate statistic model is used to link microwave propagation statistics to measurable rain statistics in order to develop international telecommunication site criteria for radio relay and communication satellite services that minimize interference between receivers and transmitters. This rain coordination procedure utilizes a rain storm cell size, a statistical description of the rainfall rate within the cell valid for most of the earth's surface, approximations between Raleigh scatter and constancy of precipitation with altitude, and an analytic relation between radar reflectivity and rain rate.

  6. RFID Transponders' Radio Frequency Emissions in Aircraft Communication and Navigation Radio Bands

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Ely, Jay J.; Williams, Reuben A.; Koppen, Sandra V.; Salud, Maria Theresa P.

    2006-01-01

    Radiated emissions in aircraft communication and navigation bands are measured from several active radio frequency identification (RFID) tags. The individual tags are different in design and operations. They may also operate in different frequency bands. The process for measuring the emissions is discussed, and includes tag interrogation, reverberation chamber testing, and instrument settings selection. The measurement results are described and compared against aircraft emission limits. In addition, interference path loss for the cargo bays of passenger aircraft is measured. Cargo bay path loss is more appropriate for RFID tags than passenger cabin path loss. The path loss data are reported for several aircraft radio systems on a Boeing 747 and an Airbus A320.

  7. Implantable Radio Frequency Identification Sensors: Wireless Power and Communication

    PubMed Central

    Hutchens, Chriswell; Rennaker, Robert L.; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2013-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700mV, 30 to 40uA load attained at −2dBm. PMID:22254944

  8. Implantable radio frequency identification sensors: wireless power and communication.

    PubMed

    Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2011-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm. PMID:22254944

  9. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or pushing..., locomotive, car, or on-track equipment, the employee directing the movement shall specify the distance of...

  10. Localization and cooperative communication methods for cognitive radio

    NASA Astrophysics Data System (ADS)

    Duval, Olivier

    We study localization of nearby nodes and cooperative communication for cognitive radios. Cognitive radios sensing their environment to estimate the channel gain between nodes can cooperate and adapt their transmission power to maximize the capacity of the communication between two nodes. We study the end-to-end capacity of a cooperative relaying scheme using orthogonal frequency-division modulation (OFDM) modulation, under power constraints for both the base station and the relay station. The relay uses amplify-and-forward and decode-and-forward cooperative relaying techniques to retransmit messages on a subset of the available subcarriers. The power used in the base station and the relay station transmitters is allocated to maximize the overall system capacity. The subcarrier selection and power allocation are obtained based on convex optimization formulations and an iterative algorithm. Additionally, decode-and-forward relaying schemes are allowed to pair source and relayed subcarriers to increase further the capacity of the system. The proposed techniques outperforms non-selective relaying schemes over a range of relay power budgets. Cognitive radios can be used for opportunistic access of the radio spectrum by detecting spectrum holes left unused by licensed primary users. We introduce a spectrum holes detection approach, which combines blind modulation classification, angle of arrival estimation and number of sources detection. We perform eigenspace analysis to determine the number of sources, and estimate their angles of arrival (AOA). In addition, we classify detected sources as primary or secondary users with their distinct second-orde one-conjugate cyclostationarity features. Extensive simulations carried out indicate that the proposed system identifies and locates individual sources correctly, even at -4 dB signal-to-noise ratios (SNR). In environments with a high density of scatterers, several wireless channels experience nonline-of-sight (NLOS

  11. 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.

  12. Radio Synthesis Imaging - A High Performance Computing and Communications Project

    NASA Astrophysics Data System (ADS)

    Crutcher, Richard M.

    The National Science Foundation has funded a five-year High Performance Computing and Communications project at the National Center for Supercomputing Applications (NCSA) for the direct implementation of several of the computing recommendations of the Astronomy and Astrophysics Survey Committee (the "Bahcall report"). This paper is a summary of the project goals and a progress report. The project will implement a prototype of the next generation of astronomical telescope systems - remotely located telescopes connected by high-speed networks to very high performance, scalable architecture computers and on-line data archives, which are accessed by astronomers over Gbit/sec networks. Specifically, a data link has been installed between the BIMA millimeter-wave synthesis array at Hat Creek, California and NCSA at Urbana, Illinois for real-time transmission of data to NCSA. Data are automatically archived, and may be browsed and retrieved by astronomers using the NCSA Mosaic software. In addition, an on-line digital library of processed images will be established. BIMA data will be processed on a very high performance distributed computing system, with I/O, user interface, and most of the software system running on the NCSA Convex C3880 supercomputer or Silicon Graphics Onyx workstations connected by HiPPI to the high performance, massively parallel Thinking Machines Corporation CM-5. The very computationally intensive algorithms for calibration and imaging of radio synthesis array observations will be optimized for the CM-5 and new algorithms which utilize the massively parallel architecture will be developed. Code running simultaneously on the distributed computers will communicate using the Data Transport Mechanism developed by NCSA. The project will also use the BLANCA Gbit/s testbed network between Urbana and Madison, Wisconsin to connect an Onyx workstation in the University of Wisconsin Astronomy Department to the NCSA CM-5, for development of long

  13. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false IFR operations: Two-way radio... RULES Flight Rules Instrument Flight Rules § 91.185 IFR operations: Two-way radio communications failure. (a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio...

  14. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false IFR operations: Two-way radio... RULES Flight Rules Instrument Flight Rules § 91.185 IFR operations: Two-way radio communications failure. (a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio...

  15. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false IFR operations: Two-way radio... RULES Flight Rules Instrument Flight Rules § 91.185 IFR operations: Two-way radio communications failure. (a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio...

  16. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false IFR operations: Two-way radio... RULES Flight Rules Instrument Flight Rules § 91.185 IFR operations: Two-way radio communications failure. (a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio...

  17. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false IFR operations: Two-way radio... RULES Flight Rules Instrument Flight Rules § 91.185 IFR operations: Two-way radio communications failure. (a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio...

  18. Radio-wave propagation for space communications systems

    NASA Technical Reports Server (NTRS)

    Ippolito, L. J.

    1981-01-01

    The most recent information on the effects of Earth's atmosphere on space communications systems is reviewed. The design and reliable operation of satellite systems that provide the many applications in space which rely on the transmission of radio waves for communications and scientific purposes are dependent on the propagation characteristics of the transmission path. The presence of atmospheric gases, clouds, fog, precipitation, and turbulence causes uncontrolled variations in the signal characteristics. These variations can result in a reduction of the quality and reliability of the transmitted information. Models and other techniques are used in the prediction of atmospheric effects as influenced by frequency, geography, elevation angle, and type of transmission. Recent data on performance characteristics obtained from direct measurements on satellite links operating to above 30 GHz have been reviewed. Particular emphasis has been placed on the effects of precipitation on the Earth/space path, including rain attenuation, and ice particle depolarization. Other factors are sky noise, antenna gain degradation, scintillations, and bandwidth coherence. Each of the various propagation factors has an effect on design criteria for communications systems. These criteria include link reliability, power margins, noise contribution, modulation and polarization factors, channel cross talk, error rate, and bandwidth limitations.

  19. STS-37 Pilot Cameron uses SAREX to communicate amateur radio operators

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Pilot Kenneth D. Cameron, wearing Shuttle Amateur Radio Experiment (SAREX) headset (HDST), communicates with amateur radio operators and students while on aft flight deck aboard Atlantis, Orbiter Vehicle (OV) 104. SAREX provided radio transmissions between ground based amateur radio operators around the world and Cameron (call sign KB5AWP) and the other crewmembers, all of whom are licensed amateur radio operators. SAREX enabled students from all over the United States to have a chance to communicate with an astronaut in space. The cloud-covered surface of the Earth is visible above Cameron framed in the overhead window W8.

  20. Impulsive consensus seeking in directed networks of multi-agent systems with communication time delays

    NASA Astrophysics Data System (ADS)

    Wu, Quanjun; Zhou, Jin; Xiang, Lan

    2012-08-01

    In this article, we consider average consensus problem in directed delayed networked multi-agent systems having impulsive effects with fixed topology and stochastic switching topology. A simple impulsive consensus protocol for such networks is proposed, and some generic criteria for solving the average consensus problem are analytically derived. It is shown that a directed delayed networked multi-agent system can achieve average consensus globally exponentially with suitable impulsive gain and impulsive interval. Subsequently, two typical illustrative examples, along with computer simulation results, are provided to visualise the effectiveness and feasibility of our theoretical results.

  1. Radio Wave Propagation Handbook for Communication on and Around Mars

    NASA Technical Reports Server (NTRS)

    Ho, Christian; Golshan, Nasser; Kliore, Arvydas

    2002-01-01

    This handbook examines the effects of the Martian environment on radio wave propagation on Mars and in the space near the planet. The environmental effects include these from the Martian atmosphere, ionosphere, global dust storms, aerosols, clouds, and geomorphologic features. Relevant Martian environmental parameters were extracted from the measurements of Mars missions during the past 30 years, especially from Mars Pathfinder and Mars Global Surveyor. The results derived from measurements and analyses have been reviewed through an extensive literature search. The updated parameters have been theoretically analyzed to study their effects on radio propagation. This handbook also provides basic information about the entire telecommunications environment on and around Mars for propagation researchers, system engineers, and link analysts. Based on these original analyses, some important recommendations have been made, including the use of the Martian ionosphere as a reflector for Mars global or trans-horizon communication between future Martian colonies, reducing dust storm scattering effects, etc. These results have extended our wave propagation knowledge to a planet other than Earth; and the tables, models, and graphics included in this handbook will benefit telecommunication system engineers and scientific researchers.

  2. High Data Rate OFDM-Based Radio over FSO Communication System Using M-QAM Modulation

    NASA Astrophysics Data System (ADS)

    Kumar, Naresh; Teixeira, Antonio Luis Jesus

    2015-12-01

    In this paper, we have presented analysis of OFDM-based Radio over FSO Communication System using M-QAM Modulation under different data rate and attenuation. A distance of 1,000 m was achieved at 10 Gbit/s data rate in OFDM-based Radio over FSO Communication System.

  3. On the Training of Radio and Communications Engineers in the Decades of the Immediate Future.

    ERIC Educational Resources Information Center

    Klyatskin, I.G.

    A list of 11 statements relating to the change in training programs for radio and communications engineers is presented in this article, in preparation for future developments in the field. Semiconductors, decimeter and centimeter radio frequency ranges, and a statistical approach to communications systems are analyzed as the three important…

  4. Analysis of Intermittency in Submillimeter Radio and Hard X-Ray Data During the Impulsive Phase of a Solar Flare

    NASA Astrophysics Data System (ADS)

    Giménez de Castro, G.; Simões, P. J. A.; Raulin, J.-P.; Guimarães, O. M.

    2016-07-01

    We present an analysis of intermittent processes occurring during the impulsive phase of the flare SOL2012-03-13, using hard X-rays and submillimeter radio data. Intermittency is a key characteristic in turbulent plasmas and has so far only been analyzed for hard X-ray data. Since in a typical flare the same accelerated electron population is believed to produce both hard X-rays and gyrosynchrotron radiation, we compare the two time profiles by searching for intermittency signatures. For this, we define a cross-wavelet power spectrum, which is used to obtain the local intermittency measure, or {LIM}. When greater than three, the square {LIM} coefficients indicate a local intermittent process. The {LIM}2 coefficient distribution in time and scale helps to identify avalanche or cascade energy release processes. We find two different and well-separated intermittent behaviors in the submillimeter data: for scales greater than 20 s, a broad distribution during the rising and maximum phases of the emission seems to favor a cascade process; for scales below 1 s, short pulses centered on the peak time are representative of avalanches. When applying the same analysis to hard X-rays, we find that only the scales above 10 s produce a distribution related to a cascade energy fragmentation. Our results suggest that different acceleration mechanisms are responsible for tens of keV and MeV energy ranges of electrons.

  5. Analysis of Intermittency in Submillimeter Radio and Hard X-Ray Data During the Impulsive Phase of a Solar Flare

    NASA Astrophysics Data System (ADS)

    Giménez de Castro, G.; Simões, P. J. A.; Raulin, J.-P.; Guimarães, O. M.

    2016-08-01

    We present an analysis of intermittent processes occurring during the impulsive phase of the flare SOL2012-03-13, using hard X-rays and submillimeter radio data. Intermittency is a key characteristic in turbulent plasmas and has so far only been analyzed for hard X-ray data. Since in a typical flare the same accelerated electron population is believed to produce both hard X-rays and gyrosynchrotron radiation, we compare the two time profiles by searching for intermittency signatures. For this, we define a cross-wavelet power spectrum, which is used to obtain the local intermittency measure, or {LIM}. When greater than three, the square {LIM} coefficients indicate a local intermittent process. The {LIM}2 coefficient distribution in time and scale helps to identify avalanche or cascade energy release processes. We find two different and well-separated intermittent behaviors in the submillimeter data: for scales greater than 20 s, a broad distribution during the rising and maximum phases of the emission seems to favor a cascade process; for scales below 1 s, short pulses centered on the peak time are representative of avalanches. When applying the same analysis to hard X-rays, we find that only the scales above 10 s produce a distribution related to a cascade energy fragmentation. Our results suggest that different acceleration mechanisms are responsible for tens of keV and MeV energy ranges of electrons.

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

    PubMed

    Ebrazeh, Ali; Bozorgzadeh, Bardia; Mohseni, Pedram

    2015-08-01

    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. PMID:26737929

  7. 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.

  8. Incorporating the Campus Radio Station into Your Emergency Communications Plan

    ERIC Educational Resources Information Center

    Johnson, Thomas C.

    2008-01-01

    Radio stations have been a mainstay of American life since the 1920s. Broadcasting primarily over AM and FM frequencies, American radio stations have been used to provide entertainment, news, weather, and advertising to the public. Beginning in 1963 and continuing until 1997, local radio stations were part of the Emergency Broadcast System (EBS)…

  9. A Simple Radio Receiver Aids Understanding of Wireless Communication

    ERIC Educational Resources Information Center

    Straulino, S.; Orlando, A.

    2012-01-01

    The basic theory of radio broadcasting is discussed from an experimental point of view. First, concepts like wave modulation and tuning are explained with the use of instruments in the physics laboratory. Then, a very basic radio receiver is described and assembled, whose most important feature, like in the old "crystal radios", is the absence of…

  10. The Great Communicator: How FDR's Radio Speeches Shaped American History

    ERIC Educational Resources Information Center

    Yu, Lumeng

    2005-01-01

    The simultaneous rise in popularity of radio and Franklin Delano Roosevelt's (FDR's) political fortune is an interesting historical twist of fate. Radio brought news alive, but left people free to create images in their imaginations. FDR's distinctive voice and jollity flowed into people's homes. His disability was invisible. Radio helped make…

  11. [Problems of harmonization of sanitary regulations of the electromagnetic fields of mobile radio communication equipment].

    PubMed

    Pal'tsev, Iu P; Pokhodzeĭ, L V; Rubtsova, N B; Bogacheva, E V

    2013-01-01

    In the article there are presented data on the probable adverse effects of electromagnetic fields generated by means of mobile cellulary radio communication equipment, a comparative analysis of hygienic rating and methods of measurement of their parameters in Russia and abroad has been performed, and the ways of harmonizing hygienic rules have been outlined, the necessity of further research to risk assessment of the use of cellular radio communication devices by population and preventive measures have been substantiated. PMID:24340578

  12. A low complexity wireless microbial fuel cell monitor using piezoresistive sensors and impulse-radio ultra-wide-band

    NASA Astrophysics Data System (ADS)

    Crepaldi, M.; Chiolerio, A.; Tommasi, T.; Hidalgo, D.; Canavese, G.; Stassi, S.; Demarchi, D.; Pirri, F. C.

    2013-05-01

    Microbial Fuel Cells (MFCs) are energy sources which generate electrical charge thanks to bacteria metabolism. Although functionally similar to chemical fuel cells (both including reactants and two electrodes, and anode and cathode), they have substantial advantages, e.g. 1) operation at ambient temperature and pressure; 2) use of neutral electrolytes and avoidance of expensive catalysts (e.g. platinum); 3) operation using organic wastes. An MFC can be effectively used in environments where ubiquitous networking requires the wireless monitoring of energy sources. We then report on a simple monitoring system for MFC comprising an ultra-low-power Impulse-Radio Ultra-Wide-Band Transmitter (TX) operating in the low 0-960MHz band and a nanostructured piezoresistive pressure sensor connected to a discrete component digital read-out circuit. The sensor comprises an insulating matrix of polydimethylsiloxane and nanostructured multi-branched copper microparticles as conductive filler. Applied mechanical stress induces a sample deformation that modulates the mean distance between particles, i.e. the current flow. The read-out circuit encodes pressure as a pulse rate variation, with an absolute sensitivity to the generated MFC voltage. Pulses with variable repetition frequency can encode battery health: the pressure sensor can be directly connected to the cells membrane to read excessive pressure. A prototype system comprises two MFCs connected in series to power both the UWB transmitter which consumes 40μW and the read-out circuit. The two MFC generate an open circuit voltage of 1.0+/-0.1V. Each MFC prototype has a total volume of 0.34L and is formed by two circular Poly(methyl methacrylate) (PMMA) chambers (anode and cathode) separated by a cation exchange membrane. The paper reports on the prototype and measurements towards a final solution which embeds all functionalities within a MFC cell. Our solution is conceived to provide energy sources integrating energy management

  13. When all else fails: 21st century Amateur Radio as an emergency communications medium.

    PubMed

    Nollet, Kenneth E; Ohto, Hitoshi

    2013-12-01

    Twenty-first century demand for radio spectrum continues to increase with the explosive growth of wireless devices, but authorities reserve slices of the spectrum for licensed Amateur Radio operators, recognizing their value to the public, particularly with respect to providing emergency communications. Blood banking and transfusion medicine are among the specialties that should also recognize the value of Amateur Radio as an emergency communications medium, because blood collection, testing, processing, storage, and transfusion are life-saving activities that in modern times can be separated by considerable distance. PMID:24041739

  14. 77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 12 and 90 Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection and Assignment of Frequencies, and Transition of the Upper 200 Channels in...

  15. 49 CFR 220.43 - Radio communications consistent with federal regulations and railroad operating rules.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... regulations and railroad operating rules. 220.43 Section 220.43 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS... regulations and railroad operating rules. Radio communication shall not be used in connection with a...

  16. Calculation of optimal operating frequencies of a communication radio line according to oblique ionosphere sounding

    NASA Astrophysics Data System (ADS)

    Vertogradov, G. G.; Uryadov, V. P.; Vertogradova, E. G.

    2008-01-01

    A hardware-software complex for real-time automatic determination of the optimal operating frequencies of a communication radio line according to oblique chirp ionosphere sounding is created. Path tests of the chirp complex on midlatitude radio lines are performed. Bit error probability and the reliability of HF communication for narrow-band and broadband communication systems are estimated from the results of oblique chirp sounding. It is shown that the quality of a communication channel greatly depends on the ratio of the regular and fluctuation components of a signal, as well as on the magnetic activity level. The created chirp complex can be used as a part of the ionospheric-wave and frequency-control service for dynamic management of the radio-line frequency resource in the interests of efficient operation of different-purpose radioelectronic systems.

  17. Irregularities in ionospheric plasma clouds: their evolution and effect on radio communication. Technical report

    SciTech Connect

    Vesecky, J.F.; Chamberlain, J.W.; Cornwall, J.M.; Hammer, D.A.; Perkins, F.W.

    1980-09-01

    Both satellite radio communications, which travel through the Earth's ionosphere, and high frequency (HF) sky wave circuits, which use the ionosphere as a refracting medium, can be strongly affected by radio wave scintillation. High altitude nuclear explosions cause scintillation (by strongly disturbing the ionosphere) and thus severely degrade satellite radio communications over a large region. Since further atmospheric nuclear tests are banned, a thorough understanding of the physics involved in both the disturbed ionosphere and its interaction with radio waves is necessary in order to design radio communications systems which will operate satisfactorily in a nuclear environment. During the 1980 JASON Summer Study we addressed some aspects of the evolution of ionospheric irregularities following a high altitude nuclear explosion--the radio wave propagation theory being apparently well understood for the satellite link case. In particular, we have worked on irregularity evolution at late times (approx. hours) after an explosion and the impact of early time irregularity structure on late time evolution. We also raise the question of scintillation effects on HF sky wave communications.

  18. Development of radio dramas for health communication pilot intervention in Canadian Inuit communities.

    PubMed

    Racicot-Matta, Cassandra; Wilcke, Markus; Egeland, Grace M

    2016-03-01

    A mixed-methods approach was used to develop a culturally appropriate health intervention over radio within the Inuit community of Pangnirtung, Nunavut (NU), Canada. The radio dramas were developed, recorded and tested pre-intervention through the use of Participatory Process and informed by the extended elaboration likelihood model (EELM) for education-communication. The radio messages were tested in two focus groups (n = 4 and n = 5) to determine fidelity of the radio dramas to the EELM theory. Focus group feedback identified that revisions needed to be made to two characteristics required of educational programmes by the EELM theorem: first, the quality of the production was improved by adding Inuit youth recorded music and second, the homophily (relatability of characters) of radio dramas was improved by re-recording the dramas with voices of local youth who had been trained in media communication studies. These adjustments would not have been implemented had pre-intervention testing of the radio dramas not taken place and could have reduced effectiveness of the overall intervention. Therefore, it is highly recommended that media tools for health communication/education be tested with the intended target audience before commencement of programmes. Participatory Process was identified to be a powerful tool in the development and sustainability of culturally appropriate community health programming. PMID:24957329

  19. A review of radio channel models for body centric communications

    PubMed Central

    Cotton, Simon L; D'Errico, Raffaele; Oestges, Claude

    2014-01-01

    The human body is an extremely challenging environment for the operation of wireless communications systems, not least because of the complex antenna-body electromagnetic interaction effects which can occur. This is further compounded by the impact of movement and the propagation characteristics of the local environment which all have an effect upon body centric communications channels. As the successful design of body area networks (BANs) and other types of body centric system is inextricably linked to a thorough understanding of these factors, the aim of this paper is to conduct a survey of the current state of the art in relation to propagation and channel models primarily for BANs but also considering other types of body centric communications. We initially discuss some of the standardization efforts performed by the Institute of Electrical and Electronics Engineers 802.15.6 task group before focusing on the two most popular types of technologies currently being considered for BANs, namely narrowband and Ultrawideband (UWB) communications. For narrowband communications the applicability of a generic path loss model is contended, before presenting some of the scenario specific models which have proven successful. The impacts of human body shadowing and small-scale fading are also presented alongside some of the most recent research into the Doppler and time dependencies of BANs. For UWB BAN communications, we again consider the path loss as well as empirical tap delay line models developed from a number of extensive channel measurement campaigns conducted by research institutions around the world. Ongoing efforts within collaborative projects such as Committee on Science and Technology Action IC1004 are also described. Finally, recent years have also seen significant developments in other areas of body centric communications such as off-body and body-to-body communications. We highlight some of the newest relevant research in these areas as well as discussing

  20. Executive summary. [application of laser oriented and radio frequency techniques for space communication

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The scope of Technology Forecasting for Space Communications is very wide, covering virtually every technology that can directly or indirectly affect space communications. The assigned effort, however, was directed toward a series of studies which individually examined important aspects of space communications and which collectively was interrelated. The contributions of the individual tasks and their interrelationship are indicated. The total effort of the tasks was fairly evenly divided between laser oriented and radio frequency tasks. The investigations show that laser communications have a current state of the art which would allow operational systems to be implemented in the 1975 to 1980 time frame. Further, these systems, when operated over ranges in the order of synchronous ranges (42,000 km)and transmitting data rates of 10 to the 8th power 10 to the 9th power bits per second will have a smaller total weight impact on a spacecraft than do radio systems.

  1. A low-power photovoltaic system with energy storage for radio communications: Description and design methodology

    NASA Technical Reports Server (NTRS)

    Chapman, C. P.; Chapman, P. D.; Lewison, A. H.

    1982-01-01

    A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.

  2. A low-power photovoltaic system with energy storage for radio communications: description and design methodology

    SciTech Connect

    Chapman, C.P.; Chapman, P.D.

    1982-01-01

    A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.

  3. Low-power photovoltaic system with energy storage for radio communications. Description and design methodology

    SciTech Connect

    Chapman, C.P.; Chapman, P.D.; Lewison, A.H.

    1982-01-15

    A low-power photovoltaic system was constructed with approximately 500 amp-hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous no-sun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.

  4. The reach and effect of radio communication campaigns on condom use in Malawi.

    PubMed

    Meekers, Dominique; Van Rossem, Ronan; Silva, Martha; Koleros, Andrew

    2007-06-01

    This study uses data from the 2004 Malawi Demographic and Health Survey to assess the reach of selected radio programs about family planning and health in Malawi and their effect on condom use and discussion of family planning. The results show that such radio programs in Malawi reach a broad audience: eight of the 12 programs were heard by at least half of the respondents, although women were less effectively reached than men. For both women and men, the radio programs were found to have a significant impact on family planning discussion with one's partner. The programs' effect on condom use was limited, however. A positive association was found with ever use of condoms, but no association was found with condom use at last intercourse. This limited impact suggests that such radio communication campaigns need to be informed by research identifying the specific constraints to current condom use in Malawi. PMID:17642412

  5. Deep null antennas and their applications to tactical VHF radio communications

    NASA Astrophysics Data System (ADS)

    Vincent, Kenneth A.

    1989-03-01

    Antennas with a characteristic cardioid radiation pattern, their applications to VHF radio communications and their design, construction and performance are examined. Structures are investigated using both the Mini Numerical Electromagnetics Code (MININEC) and the Numerical Electromagnetics Code (NEC). A test structure is built, test data obtained, and a comparison of test results versus predicted results is made.

  6. 75 FR 46854 - Amendment of the Commission's Rules Regarding Amateur Radio Service Communications During...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-04

    ... of human life and immediate protection of property when normal communication systems are not...(copyright)), or the US Department of Defense's Military Auxiliary Radio System (MARS). 9. On the other hand... operations can and have played an essential role in protecting the safety of life and property...

  7. 25 CFR 169.26 - Telephone and telegraph lines; radio, television, and other communications facilities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Telephone and telegraph lines; radio, television, and other communications facilities. 169.26 Section 169.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER RIGHTS-OF-WAY OVER INDIAN LANDS § 169.26 Telephone and telegraph...

  8. 25 CFR 169.26 - Telephone and telegraph lines; radio, television, and other communications facilities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Telephone and telegraph lines; radio, television, and other communications facilities. 169.26 Section 169.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER RIGHTS-OF-WAY OVER INDIAN LANDS § 169.26 Telephone and telegraph...

  9. 25 CFR 169.26 - Telephone and telegraph lines; radio, television, and other communications facilities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Telephone and telegraph lines; radio, television, and other communications facilities. 169.26 Section 169.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER RIGHTS-OF-WAY OVER INDIAN LANDS § 169.26 Telephone and telegraph...

  10. 25 CFR 169.26 - Telephone and telegraph lines; radio, television, and other communications facilities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Telephone and telegraph lines; radio, television, and other communications facilities. 169.26 Section 169.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER RIGHTS-OF-WAY OVER INDIAN LANDS § 169.26 Telephone and telegraph...

  11. 25 CFR 169.26 - Telephone and telegraph lines; radio, television, and other communications facilities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Telephone and telegraph lines; radio, television, and other communications facilities. 169.26 Section 169.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER RIGHTS-OF-WAY OVER INDIAN LANDS § 169.26 Telephone and telegraph...

  12. A Combined Radio and Underwater Wireless Optical Communication System based on Buoys

    NASA Astrophysics Data System (ADS)

    Song, Yuhang; Tong, Zheng; Cong, Bo; Yu, Xiangyu; Kong, Meiwei; Lin, Aobo

    2016-02-01

    We propose a system of combining radio and underwater wireless optical communication based on buoys for real-time image and video transmission between underwater vehicles and the base station on the shore. We analysis how the BER performance is affected by the link distance and the deflection angle of the light source using Monte Carlo simulation.

  13. Applications of Microwave Photonics in Radio Astronomy and Space Communication

    NASA Technical Reports Server (NTRS)

    D'Addario, Larry R.; Shillue, William P.

    2006-01-01

    An overview of narrow band vs wide band signals is given. Topics discussed included signal transmission, reference distribution and photonic antenna metrology. Examples of VLA, ALMA, ATA and DSN arrays are given. . Arrays of small antennas have become more cost-effective than large antennas for achieving large total aperture or gain, both for astronomy and for communication. It is concluded that emerging applications involving arrays of many antennas require low-cost optical communication of both wide bandwidth and narrow bandwidth; development of round-trip correction schemes enables timing precision; and free-space laser beams with microwave modulation allow structural metrology with approx 100 micrometer precision over distances of 200 meters.

  14. Wireless Phone Threat Assessment for Aircraft Communication and Navigation Radios

    NASA Technical Reports Server (NTRS)

    Nguyens, T. X.; Koppen, S. V.; Smith, L. J.; Williams, R. A.; Salud, M. T.

    2005-01-01

    Emissions in aircraft communication and navigation bands are measured for the latest generation of wireless phones. The two wireless technologies considered, GSM/GPRS and CDMA2000, are the latest available to general consumers in the U.S. A base-station simulator is used to control the phones. The measurements are conducted using reverberation chambers, and the results are compared against FCC and aircraft installed equipment emission limits. The results are also compared against baseline emissions from laptop computers and personal digital assistant devices that are currently allowed to operate on aircraft.

  15. Numerical arc segmentation algorithm for a radio conference - A software tool for communication satellite systems planning

    NASA Technical Reports Server (NTRS)

    Whyte, W. A.; Heyward, A. O.; Ponchak, D. S.; Spence, R. L.; Zuzek, J. E.

    1988-01-01

    A detailed description of a Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) software package for communication satellite systems planning is presented. This software provides a method of generating predetermined arc segments for use in the development of an allotment planning procedure to be carried out at the 1988 World Administrative Radio Conference (WARC - 88) on the use of the GEO and the planning of space services utilizing GEO. The features of the NASARC software package are described, and detailed information is given about the function of each of the four NASARC program modules. The results of a sample world scenario are presented and discussed.

  16. VibeComm: radio-free wireless communication for smart devices using vibration.

    PubMed

    Hwang, Inhwan; Cho, Jungchan; Oh, Songhwai

    2014-01-01

    This paper proposes VibeComm, a novel communication method for smart devices using a built-in vibrator and accelerometer. The proposed approach is ideal for low-rate off-line communication, and its communication medium is an object on which smart devices are placed, such as tables and desks. When more than two smart devices are placed on an object and one device wants to transmit a message to the other devices, the transmitting device generates a sequence of vibrations. The vibrations are propagated through the object on which the devices are placed. The receiving devices analyze their accelerometer readings to decode incoming messages. The proposed method can be the alternative communication method when general types of radio communication methods are not available. VibeComm is implemented on Android smartphones, and a comprehensive set of experiments is conducted to show its feasibility. PMID:25390406

  17. VibeComm: Radio-Free Wireless Communication for Smart Devices Using Vibration

    PubMed Central

    Hwang, Inhwan; Cho, Jungchan; Oh, Songhwai

    2014-01-01

    This paper proposes VibeComm, a novel communication method for smart devices using a built-in vibrator and accelerometer. The proposed approach is ideal for low-rate off-line communication, and its communication medium is an object on which smart devices are placed, such as tables and desks. When more than two smart devices are placed on an object and one device wants to transmit a message to the other devices, the transmitting device generates a sequence of vibrations. The vibrations are propagated through the object on which the devices are placed. The receiving devices analyze their accelerometer readings to decode incoming messages. The proposed method can be the alternative communication method when general types of radio communication methods are not available. VibeComm is implemented on Android smartphones, and a comprehensive set of experiments is conducted to show its feasibility. PMID:25390406

  18. RFID Transponders' RF Emissions in Aircraft Communication and Navigation Radio Bands

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Ely, Jay J.; Koppen Sandra V.; Fersch, Mariatheresa S.

    2008-01-01

    Radiated emission data in aircraft communication and navigation bands are presented for several active radio frequency identification (RFID) tags. The individual tags are different in design, operation and transmitting frequencies. The process for measuring the tags emissions in a reverberation chamber is discussed. Measurement issues dealing with tag interrogation, low level measurement in the presence of strong transmissions, and tags low duty factors are discussed. The results show strong emissions, far exceeding aircraft emission limits and can be of potential interference risks.

  19. Monitoring the Communication Channel from Puschshino to Moscow in the Project of Space Radio Telescope "radioastron"

    NASA Astrophysics Data System (ADS)

    Dumsky, D. V.; Isaev, E. A.; Samodurov, V. A.; Isaev, K. A.

    The need for transmission and storage of large amounts of scientific data in the project space radio telescope "Radioastron" required us to organize a reliable communication channel between the tracking station in Pushchino and treatment centers in Moscow. Network management data requires us to an integrated approach and covers the organization secure access to manage network devices, timely replacement of equipment and software upgrades, backups, as well as documentation of the network infrastructure. The reliability of the channel is highly dependent on continuous monitoring of network and server equipment and communication lines.

  20. Control and Non-Payload Communications Generation 1 Prototype Radio Flight Test Report

    NASA Technical Reports Server (NTRS)

    Shalkhauser, Kurt A.; Young, Daniel P.; Bretmersky, Steven C.; Ishac, Joseph A.; Walker, Steven H.; Griner, James H.; Kachmar, Brian A.

    2014-01-01

    Unmanned aircraft (UA) represent a new capability that will provide a variety of services in the Government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized because of the lack of a common understanding of what is required to safely operate Unmanned Aircraft Systems in the National Airspace System (UAS in the NAS). The desire and ability to fly UA is of increasing urgency. The application of UA to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UA to the NAS. Existing Federal Aviation Regulations, procedures, and technologies do not allow routine UA access to the NAS. Access to the NAS is hampered by challenges such as the lack of an onboard pilot to see and avoid other aircraft; the ability of a single pilot or operator to control multiple UA; the reliance on command and control (C2) links; the altitudes, speeds, and duration at which the aircraft fly; and the wide variation in UA size and performance. NASA is working with other Government agencies to provide solutions that reduce technical barriers and make access to the NAS routine. This goal will be accomplished through system-level integration of key concepts, technologies, or procedures and through demonstrations of these integrated capabilities in an operationally relevant environment. This project provides an opportunity to transition the acquired empirical data and knowledge to the Federal Aviation Administration and other stakeholders to help them define the requirements for routine UA access to the NAS.Radio communications channels for UA are currently managed through exceptions and use either Department of Defense frequencies for line-of-sight (LOS) and satellite-based communications links, low-power LOS links in amateur bands, or unlicensed Industrial/Scientific/Medical (ISM) frequencies. None of these frequency bands are designated for safety and

  1. Reconfigurable Transceiver and Software-Defined Radio Architecture and Technology Evaluated for NASA Space Communications

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.; Kacpura, Thomas J.

    2004-01-01

    The NASA Glenn Research Center is investigating the development and suitability of a software-based open-architecture for space-based reconfigurable transceivers (RTs) and software-defined radios (SDRs). The main objectives of this project are to enable advanced operations and reduce mission costs. SDRs are becoming more common because of the capabilities of reconfigurable digital signal processing technologies such as field programmable gate arrays and digital signal processors, which place radio functions in firmware and software that were traditionally performed with analog hardware components. Features of interest of this communications architecture include nonproprietary open standards and application programming interfaces to enable software reuse and portability, independent hardware and software development, and hardware and software functional separation. The goals for RT and SDR technologies for NASA space missions include prelaunch and on-orbit frequency and waveform reconfigurability and programmability, high data rate capability, and overall communications and processing flexibility. These operational advances over current state-of-art transceivers will be provided to reduce the power, mass, and cost of RTs and SDRs for space communications. The open architecture for NASA communications will support existing (legacy) communications needs and capabilities while providing a path to more capable, advanced waveform development and mission concepts (e.g., ad hoc constellations with self-healing networks and high-rate science data return). A study was completed to assess the state of the art in RT architectures, implementations, and technologies. In-house researchers conducted literature searches and analysis, interviewed Government and industry contacts, and solicited information and white papers from industry on space-qualifiable RTs and SDRs and their associated technologies for space-based NASA applications. The white papers were evaluated, compiled, and

  2. Instantaneous Impulses.

    ERIC Educational Resources Information Center

    Erlichson, Herman

    2000-01-01

    Describes an experiment that extends Newton's instantaneous-impulse method of orbital analysis to a graphical method of orbit determination. Discusses the experiment's usefulness for teaching both horizontal projectile motion and instantaneous impulse. (WRM)

  3. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Flight Test Report

    NASA Technical Reports Server (NTRS)

    Ishac, Joseph A.; Iannicca, Dennis C.; Shalkhauser, Kurt A.; Kachmar, Brian A.

    2014-01-01

    NASA Glenn Research Center conducted a series of flight tests for the purpose of evaluating air-to-ground communications links for future unmanned aircraft systems (UAS). The primary objective of the test effort was to evaluate the transition of the aircraft communications from one ground station to the next, and to monitor data flow during the "hand-off" event. To facilitate the testing, ground stations were installed at locations in Cleveland, Ohio and Albany, Ohio that each provides line-of-sight radio communications with an overflying aircraft. This report describes results from the flight tests including flight parameters, received signal strength measurements, data latency times, and performance observations for the air-to-ground channel.

  4. Development of data communication system with ultra high frequency radio wave for implantable artificial hearts.

    PubMed

    Tsujimura, Shinichi; Yamagishi, Hiroto; Sankai, Yoshiyuki

    2009-01-01

    In order to minimize infection risks of patients with artificial hearts, wireless data transmission methods with electromagnetic induction or light have been developed. However, these methods tend to become difficult to transmit data if the external data transmission unit moves from its proper position. To resolve this serious problem, the purpose of this study is to develop a prototype wireless data communication system with ultra high frequency radio wave and confirm its performance. Due to its high-speed communication rate, low power consumption, high tolerance to electromagnetic disturbances, and secure wireless communication, we adopted Bluetooth radio wave technology for our system. The system consists of an internal data transmission unit and an external data transmission unit (53 by 64 by 16 mm, each), and each has a Bluetooth module (radio field intensity: 4 dBm, receiver sensitivity: -80 dBm). The internal unit also has a micro controller with an 8-channel 10-bit A/D converter, and the external unit also has a RS-232C converter. We experimented with the internal unit implanted into pig meat, and carried out data transmission tests to evaluate the performance of this system in tissue thickness of up to 3 mm. As a result, data transfer speeds of about 20 kbps were achieved within the communication distance of 10 m. In conclusion, we confirmed that the system can wirelessly transmit the data from the inside of the body to the outside, and it promises to resolve unstable data transmission due to accidental movements of an external data transmission unit. PMID:19964616

  5. Multi-carrier transmission for hybrid radio frequency with optical wireless communications

    NASA Astrophysics Data System (ADS)

    Wang, Gang; Chen, Genshe; Shen, Dan; Pham, Khanh; Blasch, Erik; Nguyen, Tien M.

    2015-05-01

    Radio frequency (RF) wireless communication is reaching its capacity to support large data rate transmissions due to hardware constraints (e.g., silicon processes), software strategies (e.g., information theory), and consumer desire for timely large file exchanges (e.g., big data and mobile cloud computing). A high transmission rate performance must keep pace with the generated huge volumes of data for real-time processing. Integrated RF and optical wireless communications (RF/OWC) could be the next generation transmission technology to satisfy both the increased data rate exchange and the communications constraints. However, with the promising benefits of RF/OWC, challenges remain to fully develop hybrid RF with wireless optical communications such as uniform waveform design for information transmission and detection. In this paper, an orthogonal frequency division multiplexing (OFDM) transmission scheme, which widely employed in RF communications, is developed for optical communications. The traditional high peak-to-average power ratio (PAPR) in OFDM is reduced to improve system performance. The proposed multi-carrier waveform is evaluated with a frequency-selective fading channel. The results demonstrate that bit error rate (BER) performance of our proposed optical OFDM transmission technique outperforms the traditional OWC on-off keying (OOK) transmission scheme.

  6. Radio frequency interference protection of communications between the Deep Space Network and deep space flight projects

    NASA Technical Reports Server (NTRS)

    Johnston, D. W. H.

    1981-01-01

    The increasing density of electrical and electronic circuits in Deep Space Station systems for computation, control, and numerous related functions has combined with the extension of system performance requirements calling for higher speed circuitry along with broader bandwidths. This has progressively increased the number of potential sources of radio frequency interference inside the stations. Also, the extension of spectrum usage both in power and frequency as well as the greater density of usage at all frequencies for national and international satellite communications, space research, Earth resource operations and defense, and particularly the huge expansion of airborne electronic warfare and electronic countermeasures operations in the Mojave area have greatly increased the potential number and severity of radio frequency interference incidents. The various facets of this problem and the efforts to eliminate or minimize the impact of interference on Deep Space Network support of deep space flight projects are described.

  7. Empirical models of the electron concentration of the ionosphere and their value for radio communications purposes

    SciTech Connect

    Dudeney, J.R.; Kressman, R.I.

    1986-06-01

    Criteria for the development of ionosphere electron concentration vertical profile empirical models for radio communications purposes are discussed and used to evaluate and compare four contemporary schemes. Schemes must be optimized with respect to quality of profile match, availability and simplicity of the external data required for profile specification, and numerical complexity, depending on the application. It is found that the Dudeney (1978) scheme provides the best general performance, while the Booker (1977) technique is optimized for precision radio wave studies where an observed profile is available. The CCIR (Bradley and Dudeney, 1973) scheme performance is found to be inferior to the previous two, and should be superceded except where mathematical simplicity is prioritized. The International Reference Ionosphere profile is seen to have significant disadvantages with respect to all three criteria. 17 references.

  8. Empirical models of the electron concentration of the ionosphere and their value for radio communications purposes

    NASA Astrophysics Data System (ADS)

    Dudeney, J. R.; Kressman, R. I.

    1986-06-01

    Criteria for the development of ionosphere electron concentration vertical profile empirical models for radio communications purposes are discussed and used to evaluate and compare four contemporary schemes. Schemes must be optimized with respect to quality of profile match, availability and simplicity of the external data required for profile specification, and numerical complexity, depending on the application. It is found that the Dudeney (1978) scheme provides the best general performance, while the Booker (1977) technique is optimized for precision radio wave studies where an observed profile is available. The CCIR (Bradley and Dudeney, 1973) scheme performance is found to be inferior to the previous two, and should be superceded except where mathematical simplicity is prioritized. The International Reference Ionosphere profile is seen to have significant disadvantages with respect to all three criteria.

  9. Communication interference/jamming and propagation analysis system and its application to radio location

    NASA Astrophysics Data System (ADS)

    Kuzucu, H.

    1992-11-01

    Modern defense systems depend on comprehensive surveillance capability. The ability to detect and locate the radio signals is a major element of a surveillance system. With the increasing need for more mobile surveillance systems in conjunction with the rapid deployment of forces and the advent of technology allowing more enhanced use of small aperture systems, tactical direction finding (DF) and radiolocation systems will have to be operated in diverse operational conditions. A quick assessment of the error levels expected and the evaluation of the reliability of the fixes on the targeted areas bears crucial importance to the effectiveness of the missions relying on DF data. This paper presents a sophisticated, graphics workstation based computer tool developed for the system level analysis of radio communication systems and describes its use in radiolocation applications for realizing such accurate and realistic assessments with substantial money and time savings.

  10. The Radio Communication Project in Nepal: a culture-centered approach to participation.

    PubMed

    Dutta, Mohan Jyoti; Basnyat, Iccha

    2008-08-01

    Considerable research has been conducted on the topic of entertainment-education (DD), the method of using entertainment platforms such as popular music, radio, and television programming to diffuse information, attitudes, and behaviors via role modeling. A significant portion of the recently published EE literature has used the example of the Radio Communication Project (RCP) in Nepal to demonstrate the effectiveness of EE and to argue that EE campaigns can indeed be participatory in nature. In this project, we apply the culture-centered approach to examine the discursive space created by the RCP and its claim of being participatory, A critical examination of RCP discourse brings forth an alternative lens for approaching RCP and its participatory claim. PMID:18709698

  11. Amateur Radio Communications with a Deep Space Probe (Yes, It's Possible)

    NASA Astrophysics Data System (ADS)

    Cudnik, Brian; Rahman, Mahmudur; Saganti, Seth; Erickson, Gary M.; Saganti, Premkumar

    2015-05-01

    Prairie View A&M University through the collaboration with NASA-Johnson Space Center has partnered with the Kyushu Institute of Technology (KIT), Japan and developed a payload for the Shinen-2 spacecraft that was launched from Japan on December 3, 2014 as part of the Hayabusa2 mission. The main purpose of the Shinen-2 spacecraft is deep space communication experiment to test the feasibility of deep-space radio communications from the spacecraft to Earth without the need of the Deep Space Network (DSN) of NASA. This presents an opportunity to the wider community of amateur astronomers, ham radio operators, and other research personnel in that they will have the opportunity to work with deep space communication such as Shinen-2 spacecraft. It should be possible to detect a signal as an increased strength from Shinen-2 spacecraft at a rest frequency of 437.385 MHz, using commercially available equipment procured at low-cost, when the spacecraft approaches to within 3,000,000 km of the Earth during December 2015.

  12. Power consumption of communication systems employing radio-over-fiber distributed antenna systems for railway

    NASA Astrophysics Data System (ADS)

    Pham, Tien Dat; Kanno, Atsushi; Kawanishi, Tetsuya

    2013-01-01

    Demand on high speed communication and broadband access connection for fast moving passengers is rapidly increasing. However, the current wireless access communication techniques for railway which are mainly based on GSM for rail, satellite, and macro-cell cellular networks cannot meet the requirement of communication on fast moving trains. Cellular networks with small cell size and high carrier frequencies can be realized as a promising solution to overcome the current obstacles. In that situation, a radio-over-fiber distributed antenna system using WDM technology can be an attractive means to connect small base stations along the railway track to the control centers. However, considering a huge number of base stations placed along the railway track, power consumption will become one of the main concerns. In this paper, we investigate and optimize power consumption and energy efficiency of a Radio-over-Fiber distributed antenna system (RoF DAS) for railway. Based on the model, optimum system design in terms of remote antenna cell size and number of cells in a WDM ring are derived with respect to system energy consumption and efficiency. From the model we can also determine an appropriate scheme to upgrade a currently deployed conventional cellular network to a system employing RoF DAS technology. The power consumption and energy efficiency of the conventional and the upgraded systems are compared. The results demonstrate a significant save of power consumption and remarkable enhancement of energy efficiency when using a RoF DAS system.

  13. Spectrum survey for reliable communications of cognitive radio based smart grid network

    NASA Astrophysics Data System (ADS)

    Farah Aqilah, Wan; Jayavalan, Shanjeevan; Mohd Aripin, Norazizah; Mohamad, Hafizal; Ismail, Aiman

    2013-06-01

    The smart grid (SG) system is expected to involve huge amount of data with different levels of priorities to different applications or users. The traditional grid which tend to deploy propriety networks with limited coverage and bandwidth, is not sufficient to support large scale SG network. Cognitive radio (CR) is a promising communication platform for SG network by utilizing potentially all available spectrum resources, subject to interference constraint. In order to develop a reliable communication framework for CR based SG network, thorough investigations on the current radio spectrum are required. This paper presents the spectrum utilization in Malaysia, specifically in the UHF/VHF bands, cellular (GSM 900, GSM 1800 and 3G), WiMAX, ISM and LTE band. The goal is to determine the potential spectrum that can be exploit by the CR users in the SG network. Measurements was conducted for 24 hours to quantify the average spectrum usage and the amount of available bandwidth. The findings in this paper are important to provide insight of actual spectrum utilization prior to developing a reliable communication platform for CR based SG network.

  14. The Hitachi and Takahagi 32 m radio telescopes: Upgrade of the antennas from satellite communication to radio astronomy

    NASA Astrophysics Data System (ADS)

    Yonekura, Yoshinori; Saito, Yu; Sugiyama, Koichiro; Soon, Kang Lou; Momose, Munetake; Yokosawa, Masayoshi; Ogawa, Hideo; Kimura, Kimihiro; Abe, Yasuhiro; Nishimura, Atsushi; Hasegawa, Yutaka; Fujisawa, Kenta; Tomoaki, Oyama; Kono, Yusuke; Miyamoto, Yusuke; Sawada-Satoh, Satoko; Hideyuki, Kobayashi; Kawaguchi, Noriyuki; Honma, Mareki; Shibata, Katsunori M.; Sato, Katsuhisa; Ueno, Yuji; Jike, Takaaki; Tamura, Yoshiaki; Hirota, Tomoya; Miyazaki, Atsushi; Niinuma, Kotaro; Sorai, Kazuo; Takaba, Hiroshi; Hachisuka, Kazuya; Kondo, Tetsuro; Sekido, Mamoru; Murata, Yasuhiro; Nakai, Naomasa; Omodaka, Toshihiro

    2016-05-01

    The Hitachi and Takahagi 32 m radio telescopes (former satellite communication antennas) were so upgraded as to work at 6, 8, and 22 GHz. We developed the receiver systems, IF systems, back-end systems (including samplers and recorders), and reference systems. We measured the performance of the antennas. The system temperature including the atmosphere toward the zenith, T_sys^{ast }, is measured to be ˜30-40 K for 6 GHz and ˜25-35 K for 8 GHz. T_sys^{ast } for 22 GHz is measured to be ˜40-100 K in winter and ˜150-500 K in summer seasons, respectively. The aperture efficiency is 55%-75% for Hitachi at 6 GHz and 8 GHz, and 55%-65% for Takahagi at 8 GHz. The beam sizes at 6 GHz and 8 GHz are ˜4{^'.}6 and ˜3{^'.}8, respectively. The side-lobe level is less than 3%-4% at 6 and 8 GHz. Pointing accuracy was measured to be better than ˜0{^'.}3 for Hitachi and ˜0{^'.}6 for Takahagi. We succeeded in VLBI observations in 2010 August, indicating good performance of the antenna. We started single-dish monitoring observations of 6.7 GHz methanol maser sources in 2012 December, and found several new sources showing short-term periodic variation of the flux density.

  15. Sensing using eigenchannels in radio-frequency multiple-input, multiple-output communication systems

    NASA Astrophysics Data System (ADS)

    Bikhazi, Nicolas; Young, William F.; Nguyen, Hung

    2011-06-01

    This paper describes the use of multiple-input, multiple-output (MIMO) communication technology as a radio frequency (RF) sensor. We suggest some possible measures for determining how the changes in MIMO channel are related to objects moving through the MIMO channel. Initially, we examine the singular values of the channel matrix. We further demonstrate the effects of the signal-to-noise ratio (SNR) in conjunction with the target physical properties in the creation of eigenchannels. These eigenchannels represent the key factor in the ability of a MIMO system to perform as an effective sensor. Another important feature of MIMO technology is that it allows us to capture spatial information about the target, beyond the typical time and frequency information. Preliminary experimental results at 750 MHz demonstrate that targets can be detected and distinguished based on these simple measures. For example, a vehicular target is distinguishable from a person or groups of people. Our concept is closely related to a MIMO radar approach. However, a key difference is that we make use of the natural process of establishing a MIMO communication link rather than interrogate a specific physical region via a pulsed RF waveform. MIMO communications requires sounding of the physical environment and the creation of a channel matrix in order to maximize data throughput. We leverage this information about the area of interest already captured by the communication system. This allows the use of a MIMO system for both sensing and communication.

  16. The influence of alcohol and aging on radio communication during flight.

    PubMed

    Morrow, D; Leirer, V; Yesavage, J

    1990-01-01

    This study finds that alcohol and pilot age impair radio communication during simulated flight. Young (mean age 25 years) and older (mean age 42 years) pilots flew in a light aircraft simulator during alcohol and placebo conditions. In the alcohol condition, pilots drank alcohol and flew after reaching 0.04% BAC, after reaching 0.10% BAC, and then 2, 4, 8, 24, and 48 h after they stopped drinking at 0.10% BAC. They flew at the same times in the placebo condition. Alcohol and age impaired communication-based and overall flying performance during and immediately after drinking. Most important, alcohol and age cumulatively impaired performance, since older pilots were more impaired by alcohol. Notably, performance was as impaired 2 h after reaching 0.10% BAC as it was at 0.10% BAC. Moreover, overall performance was impaired for 8 h after reaching 0.10% BAC. PMID:2302121

  17. Pulsed radio frequency interference effects on data communications via satellite transponder

    NASA Technical Reports Server (NTRS)

    Weinberg, A.; Hong, Y.

    1979-01-01

    Power-limited communication links may be susceptible to significant degradation if intentional or unintentional pulsed high level radio frequency interference (RFI) is present. Pulsed RFI is, in fact, of current interest to NASA in studies relating to its Tracking and Data Relay Satellite System (TDRSS). The present paper examines the impact of pulsed RFI on the error probability performance of a power-limited satellite communication link: the assumed modulation scheme is PN coded binary PSK. The composite effects of thermal noise, pulsed CW and pulsed Gaussian noise are analyzed, where RFI arrivals are assumed to follow Poisson statistics. Under the assumption that the satellite repeater is ideal and that integrate and dump filtering is employed at the ground receiver, an exact error probability expression and associated approximations are derived. Computed results are generated using an arbitrarily specified RFI model.

  18. Design of Radio Frequency Link in Automatic Test System for Multimode Mobile Communication Base Station

    NASA Astrophysics Data System (ADS)

    Zhang, Weipeng

    2015-12-01

    A modularized design for the radio frequency (RF) link in automatic test system of multimode mobile communication base station is presented, considering also the characteristics of wireless communication indices and composition of signals of base stations. The test link is divided into general module, time division duplex (TDD) module, module of spurious noise filter, module of downlink intermodulation, module of uplink intermodulation and uplink block module. The composition of modules and link functions are defined, and the interfaces of the general module and the module of spurious noise filter are described. Finally, the estimated gain budget of the test link is presented. It is verified by experiments that the system is reliable and the test efficiency is improved.

  19. Third Generation Wireless Phone Threat Assessment for Aircraft Communication and Navigation Radios

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Smith, Laura J.; Williams, Reuben A.; Salud, Maria Theresa P.

    2005-01-01

    Radiated emissions in aircraft communication and navigation bands are measured from third generation (3G) wireless mobile phones. The two wireless technologies considered are the latest available to general consumers in the US. The measurements are conducted using reverberation chambers. The results are compared against baseline emissions from laptop computers and personal digital assistant devices that are currently allowed to operate on aircraft. Using existing interference path loss data and receivers interference threshold, a risk assessment is performed for several aircraft communication and navigation radio systems. In addition, cumulative interference effects of multiple similar devices are conservatively estimated or bounded. The effects are computed by summing the interference power from individual devices that is scaled according to the interference path loss at its location.

  20. Solar Paddle Antenna on Pico-Satellite for Amateur Radio Communication

    NASA Astrophysics Data System (ADS)

    Nohmi, Masahiro; Oi, Katsumi; Takuma, Satoshi; Ogawa, Masaaki

    This paper describes solar paddle antenna proposed in the development of Kagawa Satellite "KUKAI." KUKAI is a mother-daughter pico-satellite for technical verification of a tethered space robot. The mother and the daughter satellites communicate respectively with the ground station by amateur radio frequencies. For the purpose of simple deployment system on orbit and antenna directivity suitable for KUKAI, solar paddle antenna mounted at the edge of a solar paddle is employed. After sufficient antenna adjustment on the ground, KUKAI was launched on 23 January 2009 by the H-IIA rocket from Tanegashima Space Center. The solar paddles were successfully deployed, and communication by the solar paddle antenna was successful.

  1. Impact of the integrated Radio Communication Project in Nepal, 1994-1997.

    PubMed

    Storey, D; Boulay, M; Karki, Y; Heckert, K; Karmacharya, D M

    1999-01-01

    The Radio Communication Project (RCP) in Nepal is an ongoing, theory-based, multimedia reproductive health campaign which began in 1995. It consists of two entertainment-education radio serials (a soap opera for the general public and a dramatized distance education serial for health workers), additional radio spot advertisements and promotions, and complementary print materials. This paper examines impact data from a variety of sources, including a pre- and postpanel survey of currently married women (N = 1905), three waves of clinic-based observations of client-provider interactions (N = 240 per wave) and client exit interviews (N = 240 per wave), and 2 years of clinic service statistics, in order to draw inferences about the separate and combined effects of the RCP components. The study found increased health worker interpersonal interaction skills, improved quality of client-provider interactions, increased client self-efficacy in dealing with health workers, improved client attitudes toward health services and toward the practice of family planning, increased adoption of family planning, and increased family planning service utilization, all attributable to the RCP. The panel data allowed statistical control of the influence of predisposing factors before the campaign on postcampaign ideation and behavior. The effect of the RCP on contraceptive behavior was largely indirect through its influence on ideation. Implications for the design of integrated, multimedia, entertainment-education campaigns and integrated evaluation designs are discussed. PMID:10790785

  2. Plastic circuits and tags for 13.56 MHz radio-frequency communication

    NASA Astrophysics Data System (ADS)

    Myny, Kris; Steudel, Soeren; Vicca, Peter; Beenhakkers, Monique J.; van Aerle, Nick A. J. M.; Gelinck, Gerwin H.; Genoe, Jan; Dehaene, Wim; Heremans, Paul

    2009-12-01

    We discuss the design and implementation of 64-bit and 128-bit plastic transponder chips for radio-frequency identification tags. The 64-bit chips, comprising 414 organic thin-film transistors, are integrated into fully functional plastic radio-frequency identification tags with 13.56 MHz communication. The required supply voltage on the tag is generated from the AC input signal detected by the antenna, using a plastic double half-wave rectifier circuit. The tag is fully functional at a magnetic field strength of 1.26 A/m, which is below the minimum required radio-frequency magnetic field stated in the standards. We discuss the reading distance that can be achieved with our plastic rectifiers, and show that this reading distance is not limited by the performance of the plastic rectifier or transponder chip. The 128-bit transponder chip includes further features such as Manchester data encoding and a basic ALOHA anti-collision protocol. It employs 1286 organic thin-film transistors and generates the 128 bit sequence at 24 V supply voltage at a data rate of 1.5 kb/s. Data rates up to 2 kb/s could be achieved on chips with an 8-bit transponder chip.

  3. A Lightweight Radio Propagation Model for Vehicular Communication in Road Tunnels.

    PubMed

    Qureshi, Muhammad Ahsan; Noor, Rafidah Md; Shamim, Azra; Shamshirband, Shahaboddin; Raymond Choo, Kim-Kwang

    2016-01-01

    Radio propagation models (RPMs) are generally employed in Vehicular Ad Hoc Networks (VANETs) to predict path loss in multiple operating environments (e.g. modern road infrastructure such as flyovers, underpasses and road tunnels). For example, different RPMs have been developed to predict propagation behaviour in road tunnels. However, most existing RPMs for road tunnels are computationally complex and are based on field measurements in frequency band not suitable for VANET deployment. Furthermore, in tunnel applications, consequences of moving radio obstacles, such as large buses and delivery trucks, are generally not considered in existing RPMs. This paper proposes a computationally inexpensive RPM with minimal set of parameters to predict path loss in an acceptable range for road tunnels. The proposed RPM utilizes geometric properties of the tunnel, such as height and width along with the distance between sender and receiver, to predict the path loss. The proposed RPM also considers the additional attenuation caused by the moving radio obstacles in road tunnels, while requiring a negligible overhead in terms of computational complexity. To demonstrate the utility of our proposed RPM, we conduct a comparative summary and evaluate its performance. Specifically, an extensive data gathering campaign is carried out in order to evaluate the proposed RPM. The field measurements use the 5 GHz frequency band, which is suitable for vehicular communication. The results demonstrate that a close match exists between the predicted values and measured values of path loss. In particular, an average accuracy of 94% is found with R2 = 0.86. PMID:27031989

  4. A Lightweight Radio Propagation Model for Vehicular Communication in Road Tunnels

    PubMed Central

    Shamim, Azra; Shamshirband, Shahaboddin; Raymond Choo, Kim-Kwang

    2016-01-01

    Radio propagation models (RPMs) are generally employed in Vehicular Ad Hoc Networks (VANETs) to predict path loss in multiple operating environments (e.g. modern road infrastructure such as flyovers, underpasses and road tunnels). For example, different RPMs have been developed to predict propagation behaviour in road tunnels. However, most existing RPMs for road tunnels are computationally complex and are based on field measurements in frequency band not suitable for VANET deployment. Furthermore, in tunnel applications, consequences of moving radio obstacles, such as large buses and delivery trucks, are generally not considered in existing RPMs. This paper proposes a computationally inexpensive RPM with minimal set of parameters to predict path loss in an acceptable range for road tunnels. The proposed RPM utilizes geometric properties of the tunnel, such as height and width along with the distance between sender and receiver, to predict the path loss. The proposed RPM also considers the additional attenuation caused by the moving radio obstacles in road tunnels, while requiring a negligible overhead in terms of computational complexity. To demonstrate the utility of our proposed RPM, we conduct a comparative summary and evaluate its performance. Specifically, an extensive data gathering campaign is carried out in order to evaluate the proposed RPM. The field measurements use the 5 GHz frequency band, which is suitable for vehicular communication. The results demonstrate that a close match exists between the predicted values and measured values of path loss. In particular, an average accuracy of 94% is found with R2 = 0.86. PMID:27031989

  5. An estimation of the LF-MF high latitude communication radio lines range on surface electromagnetic waves

    NASA Astrophysics Data System (ADS)

    Bashkuev, Yu. B.; Dembelov, M. G.; Angarkhaeva, L. Kh.; Naguslaeva, I. B.; Khaptanov, V. B.; Buyanova, D. G.

    2015-11-01

    The paper is devoted to estimation of the LF-MF high latitude communication radio lines range on surface electromagnetic waves (SEW). A surface impedance of sea areas of water in summer and winter time is considered. An example of calculations of the ground wave field over inhomogeneous impedance paths including stratified inhomogeneous structure "ice-sea" is given. It is shown that due to the emergence of SEW the Arctic radio lines range increases significantly.

  6. Radios in the Classroom: Curriculum Integration and Communication Skills. ERIC Digest.

    ERIC Educational Resources Information Center

    Ninno, Anton

    Teachers have explored the use of radio in the classroom almost since radio technology entered into the mainstream of society, yet radio remains a relatively unused mode of instruction. This Digest describes several radio applications and summarizes various radio activities to assist teachers in integrating technology into the curriculum.…

  7. Application of semiconductor optical amplifier for mobile radio communications networks based on radio-over-fiber systems

    NASA Astrophysics Data System (ADS)

    Andreev, Vladimir A.; Burdin, Vladimir A.; Volkov, Kirill A.; Dashkov, Michael V.; Bukashkin, Sergei A.; Buzov, Alexander L.; Procopiev, Vladimir I.; Zharkov, Alexander D.

    2016-03-01

    The analysis of semiconductor optical amplifier applications in Radio-over-Fiber systems of telecommunication networks is given. In such systems semiconductor optical amplifier can be used for either amplification, modulation or detection, and also as an universal device.

  8. A paid radio advertising campaign to promote parent-child communication about alcohol.

    PubMed

    Surkan, Pamela J; Dejong, William; Herr-Zaya, Kathleen M; Rodriguez-Howard, Mayra; Fay, Kevin

    2003-01-01

    This study assessed the impact of a paid radio commercial designed to promote parent-child communication about alcohol use and sponsored by the Bureau of Substance Abuse Services, Massachusetts Department of Public Health. A random-digit-dial telephone survey of parents or guardians of children ages 10-17 years was conducted after a four-week advertising flight. Respondents with unassisted recall of the commercial more often disagreed that parent-child discussion is useful only if children have begun to experiment with alcohol, and more often reported having three or more parent-child discussions about alcohol compared to those who did not recall the commercial. Findings suggest the potential benefit of paid media campaigns to encourage parents to talk with their children about alcohol. PMID:14530150

  9. SETI: The transmission rate of radio communication and the signal's detection

    NASA Astrophysics Data System (ADS)

    Fridman, P. A.

    2011-11-01

    The transmission rate of communication between radio telescopes on Earth and extraterrestrial intelligence (ETI) is here calculated up to distances of 1000 light years. Both phase-shift keying (PSK) and frequency-shift keying (FSK) modulation schemes are considered. It is shown that M-ary FSK is advantageous in terms of energy. Narrow-band pulses scattered over the spectrum sharing a common drift rate can be the probable signals of ETI. Modern SETI spectrum analyzers are well suited to searching for these types of signals. Such signals can be detected using the Hough transform which is a dedicated tool for detecting patterns in an image. The time-frequency plane representing the power output of the spectrum analyzer during the search for ETI gives an image from which the Hough transform (HT) can detect signal patterns with frequency drift.

  10. Transmit-reference methods in software defined radio platforms for communication in harsh propagation environments and systems thereof

    DOEpatents

    Dowla, Farid U; Nekoogar, Faranak

    2015-03-03

    A method for adaptive Radio Frequency (RF) jamming according to one embodiment includes dynamically monitoring a RF spectrum; detecting any undesired signals in real time from the RF spectrum; and sending a directional countermeasure signal to jam the undesired signals. A method for adaptive Radio Frequency (RF) communications according to another embodiment includes transmitting a data pulse in a RF spectrum; and transmitting a reference pulse separated by a predetermined period of time from the data pulse; wherein the data pulse is modulated with data, wherein the reference pulse is unmodulated. A method for adaptive Radio Frequency (RF) communications according to yet another embodiment includes receiving a data pulse in a RF spectrum; and receiving a reference pulse separated in time from the data pulse, wherein the data pulse is modulated with data, wherein the reference pulse is unmodulated; and demodulating the pulses.

  11. Community Participation, Cultural Discourse, and Health Education Projects in Developing Areas: The Case of the Radio Communication Project in Nepal

    ERIC Educational Resources Information Center

    Linn, J. Gary

    2008-01-01

    In this article, the author comments on the article by Dutta and Basnyat (see EJ802883) that provides an insightful and comprehensive critique of a United States Agency for International Development (USAID) entertainment-education program, The Radio Communication Program (RCP) in Nepal, which has been reported to be highly participatory. Despite…

  12. Radio Wave Propagation for Communication on and around Mars. Part 1; Highlights: Propagation Through Mars Environment

    NASA Technical Reports Server (NTRS)

    Ho, Christian; Golshan, Nasser

    1999-01-01

    We recommend to use the dayside Martian ionosphere as a reflector for global communication, because the dayside ionosphere has stable density peak and usable critic frequency. This is very crucial for the future Mars ground to around communication. The dayside ionosphere has been well modeled as a Chapman layer. We suggest to perform the Martian nightside ionospheric modeling study. Because the nightside ionosphere has very little measurements available, we propose to drop a digital ionosond instrument into the Mars surface for data collection. Even though the Martian tropospheric radio refractivity has small value, it still can cause the ray bending and multipath effects. We recommend to perform an accurate calculation on excess phase and group delays (range and time delays). Other effects, such as range rate errors, appearance angle deviation, defocusing loss on Mars, etc. are also needed to be estimated. Ice depolarization effects due to Martian clouds on radio waves is unknown yet, which is expected to be small, because lower optical depth and thinner layer of cloud: Total Martian atmospheric gaseous attenuation is expected to be less than 1 dB on microwaves band, because the Martian atmosphere has very low concentration in uncondensed H2O and O2. An accurate calculation for zenith opacity requires the information about scale heights of H2O and O2 distribution. An accurate water vapor altitude profile at Mars is not available yet. Under the normal condition, CO2 and N2 gases do not have electric or magnetic dipoles and do not absorb electromagnetic energy from the waves. However, they may generate the dipoles through a collision and interact with waves under a high density condition and absorb electromagnetic waves in the infrared and visible band. Dust storm is most dominant factor to the radio wave attenuation. Large Martian dust storm can cause at least 3 dB or higher loss to Ka band wave. For a normal dust storm, the attenuation is about 1 dB. The

  13. Analysis of the Throughput of the Cellular Radio-Communication Systems Using Coordinated Data Transmission to Suppress Mutual Unintended Interference

    NASA Astrophysics Data System (ADS)

    Morozov, G. V.; Davydov, A. V.; Mal'tsev, A. A.

    2014-08-01

    We present the results of the comparative analysis of two data-transmission schemes of the fourth-generation cellular communication standard LTE-A, which use the "quasistatic" and "dynamic" coordination at the neighbor base stations. Both schemes are used to suppress mutual unintended co-channel interference resulting from the repeated use of one frequency channel by the neighbor base stations. The general case of the heterogeneous cellular radio-communication system with different station types (macro- and picostations) is considered. In this work, the efficiency of the coordinated-transmission schemes is studied along with the adaptive algorithms for the dataflow planning and control. The use of both coordination schemes is comparatively analyzed. An original algorithm for redistribution of the user connections is proposed for the dynamic scheme and the dependence of the communication-system throughput on the radio-network configuration and the number of base stations, that participate in the coordination is studied.

  14. Cryogenically cooled low-noise amplifier for radio-astronomical observations and centimeter-wave deep-space communications systems

    NASA Astrophysics Data System (ADS)

    Vdovin, V. F.; Grachev, V. G.; Dryagin, S. Yu.; Eliseev, A. I.; Kamaletdinov, R. K.; Korotaev, D. V.; Lesnov, I. V.; Mansfeld, M. A.; Pevzner, E. L.; Perminov, V. G.; Pilipenko, A. M.; Sapozhnikov, B. D.; Saurin, V. P.

    2016-01-01

    We report a design solution for a highly reliable, low-noise and extremely efficient cryogenically cooled transmit/receive unit for a large antenna system meant for radio-astronomical observations and deep-space communications in the X band. We describe our design solution and the results of a series of laboratory and antenna tests carried out in order to investigate the properties of the cryogenically cooled low-noise amplifier developed. The transmit/receive unit designed for deep-space communications (Mars missions, radio observatories located at Lagrangian point L2, etc.) was used in practice for communication with live satellites including "Radioastron" observatory, which moves in a highly elliptical orbit.

  15. Talk radio as the soundtrack of our lives: Participatory HIV/AIDS communication, public self-expression and Positive Talk.

    PubMed

    Burger, Mariekie

    2015-01-01

    Despite the many HIV/AIDS communication initiatives, combined with support and infrastructural support in South Africa, risky behaviour associated with the spread of the epidemic is increasing amongst many groups. This calls for a re-evaluation of endeavours aimed at curbing the spread of the epidemic. This article is only concerned with the communicational aspects of the epidemic, but does not negate the interaction of these with other measures taken to address the epidemic. As is the case with most health communication initiatives, HIV/AIDS communication initiatives have evolved to favour the participatory approach above one-directional transmission of information to the public. The participatory approach rests on the assumption that an HIV/AIDS communication initiative stands the best chance of resulting in behaviour change if members of the target community participate in the communication initiative. The assumption is that as many people as possible should be involved in the maximum number of phases of the communicative initiative (such as initial research, planning, implementation and evaluation of the project). Some research has recently started to explore new forms of community participation, including inviting community participation through, for example, internet-based platforms such as social media, and mobile phone platforms such as WhatsApp and BBM. However, the reality broadcast genre--more specifically, talk radio--has been neglected, as only a few research investigations focused on talk radio and most of these are not exclusively about HIV/AIDS communication but focus on other health topics. From a participatory communication perspective, two sets of critique against the existing HIV/AIDS communication projects hold water: firstly, they do not make the maximum use of participatory communication principles and, secondly, they are externally initiated projects and emanate from outside the target community. To address both of these concerns, this

  16. Educational Radio.

    ERIC Educational Resources Information Center

    Arafeh, Sousan

    1999-01-01

    Examines the effectiveness of the radio in education and the crucial role of the radio in distance education in first half of the 20th century; dramatic social changes in the 1960s that led to a review of educational institutions and of educational media; and the radio today as a neglected but inexpensive medium of communication that should be…

  17. Socio-Economic Aspects of National Communication Systems: III. Radio Broadcasting in Venezuela. Communication and Society, 12.

    ERIC Educational Resources Information Center

    Capriles, Oswaldo; And Others

    The third in a series that examines the role of radio broadcasting in the process of socioeconomic and cultural change in three countries with different types of broadcasting organization--Austria, Czechoslovakia, and Venezuela--this volume focuses on Venezuela. An overview of radio broadcasting in Venezuela describes various aspects and provides…

  18. Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs.

    PubMed

    Sayyed, Ali; de Araújo, Gustavo Medeiros; Bodanese, João Paulo; Becker, Leandro Buss

    2015-01-01

    The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node. PMID:26389911

  19. Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs

    PubMed Central

    Sayyed, Ali; Medeiros de Araújo, Gustavo; Bodanese, João Paulo; Buss Becker, Leandro

    2015-01-01

    The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node. PMID:26389911

  20. Forecasting ionospheric space weather with applications to satellite drag and radio wave communications and scintillation

    NASA Astrophysics Data System (ADS)

    Mannucci, Anthony J.; Tsurutani, Bruce T.; Verkhoglyadova, Olga P.; Meng, Xing; Pi, Xiaoqing; Kuang, Da; Wang, Chunming; Rosen, Gary; Ridley, Aaron; Lynch, Erin; Sharma, Surja; Manchester, Ward B.; van der Holst, Bart

    2015-04-01

    The development of quantitative models that describe physical processes from the solar corona to the Earth’s upper atmosphere opens the possibility of numerical space weather prediction with a lead-time of a few days. Forecasting solar wind-driven variability in the ionosphere and thermosphere poses especially stringent tests of our scientific understanding and modeling capabilities, in particular of coupling processes to regions above and below. We will describe our work with community models to develop upper atmosphere forecasts starting with the solar wind driver. A number of phenomena are relevant, including high latitude energy deposition, its impact on global thermospheric circulation patterns and composition, and global electrodynamics. Improved scientific understanding of this sun to Earth interaction ultimately leads to practical benefits. We will focus on two ways the upper atmosphere affects life on Earth: by changing satellite orbits, and by interfering with long-range radio communications. Challenges in forecasting these impacts will be addressed, with a particular emphasis on the physical bases for the impacts, and how they connect upstream to the sun and the heliosphere.

  1. Comparative Study of Optical and Radio-Frequency Communication Systems for a Deep-Space Mission

    NASA Technical Reports Server (NTRS)

    Hemmati, H.; Wilson, K.; Sue, M. K.; Harcke, L. J.; Wilhelm, M.; Chen, C.-C.; Lesh, J.; Feria, Y.; Rascoe, D.; Lansing, F.

    1997-01-01

    We have performed a study on telecommunication systems for a hypothetical mission to Mars. The objective of the study was to evaluate and compare the benefits that microwave-X-band (8.4 GHz) and Ka-band (32 GHz) - and optical communications technologies a afford to future missions. The telecommunication systems were required to return data after launch and in orbit at 2.7 AU with daily data volumes of 0.1, 1.0, or 10.0 Gbits (Gb). Spacecraft terminals capable of delivering each of the three data volumes were proposed and characterized in terms of mass, power consumption, size, and cost. The estimated parameters for X-band, Ka-band, and optical frequencies are compared and presented here. For all cases, the optical light terminal exhibits about 60 percent of the mass of the corresponding radio frequency (RF) subsystem. Power consumption is comparable for all three technologies at a 0.1 Gb/day data volume, but the power required at either Ka-band or optical is less than half of the X-band requirement at 10 Gb/day. These benefits can be obtained only with a suitable investment in reception facilities for Ka-band or optical frequencies.

  2. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Flight Test Report

    NASA Technical Reports Server (NTRS)

    Iannicca, Dennis C.; Ishac, Joseph A.; Shalkhauser, Kurt A.

    2015-01-01

    NASA Glenn Research Center (GRC), in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the Federal Aviation Administration (FAA) and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the GRC prototype CNPC architecture as a demonstration platform. The proposed security controls were integrated into the GRC flight test system aboard our S-3B Viking surrogate aircraft and several network tests were conducted during a flight on November 15th, 2014 to determine whether the controls were working properly within the flight environment. The flight test was also the first to integrate Robust Header Compression (ROHC) as a means of reducing the additional overhead introduced by the security controls and Mobile IPv6. The effort demonstrated the complete end-to-end secure CNPC link in a relevant flight environment.

  3. Communication

    NASA Technical Reports Server (NTRS)

    Griner, James

    2010-01-01

    NASA s communication work for the UAS Command and Control area will build upon work currently being conducted under NASA Recovery Act funds. Communication portions of UAS NextGen ConOps, Stateof- the-Art assessment, and Gap Analysis. Preliminary simulations for UAS CNPC link scalability assessment. Surrogate UAS aircraft upgrades. This work will also leverage FY10 in-guide funding for communication link model development. UAS are currently managed through exceptions and are operating using DoD frequencies for line-of-sight (LOS) and satellite-based communications links, low-power LOS links in amateur bands, or unlicensed Instrument/Scientific/Medical (ISM) frequencies. None of these frequency bands are designated for Safety and Regularity of Flight. No radio-frequency (RF) spectrum has been allocated by the International Telecommunications Union (ITU) specifically for UAS command and control links, for either LOS or Beyond LOS (BLOS) communication.

  4. Interconnection of private land mobile radio systems with the public switched telephone network in certain MHz bands--Federal Communications Commission. Final rule.

    PubMed

    1982-04-23

    This document adopts new rules to enable private radio communication systems licensed under Part 90 in the 800 MHz bands to interconnect with the facilities of the public switched telephone network. These rules are necessary to enable private licensees to better utilize their radio systems by allowing interconnected operation under certain conditions. An accompanying petition for rulemaking is dismissed as moot. PMID:10255452

  5. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Architecture Lab Test Report

    NASA Technical Reports Server (NTRS)

    Iannicca, Dennis C.; McKim, James H.; Stewart, David H.; Thadhani, Suresh K.; Young, Daniel P.

    2015-01-01

    NASA Glenn Research Center, in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the FAA and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the current GRC prototype CNPC architecture as a demonstration platform. The security controls were integrated into a lab test bed mock-up of the Mobile IPv6 architecture currently being used for NASA flight testing, and a series of network tests were conducted to evaluate the security overhead of the controls compared to the baseline CNPC link without any security. The aim of testing was to evaluate the performance impact of the additional security control overhead when added to the Mobile IPv6 architecture in various modes of operation. The statistics collected included packet captures at points along the path to gauge packet size as the sample data traversed the CNPC network, round trip latency, jitter, and throughput. The effort involved a series of tests of the baseline link, a link with Robust Header Compression (ROHC) and without security controls, a link with security controls and without ROHC, and finally a link with both ROHC and security controls enabled. The effort demonstrated that ROHC is both desirable and necessary to offset the additional expected overhead of applying security controls to the CNPC link.

  6. The Application of the 900 MHz Band to Law Enforcement Communications: An Analysis of Technical and Regulatory Factors Affecting the Applicability of the 900 MHz Portion of the Radio Spectrum to Law Enforcement Communication System Problems.

    ERIC Educational Resources Information Center

    Kavanagh, Donal D.

    The Federal Communications Commission's opening of the 900 MHz spectrum for use by the land mobile radio community was a landmark event in the history of mobile radio in the United States, as this action almost doubled the amount of spectrum available. This report describes the current regulatory environment, analyzes the applicability of 900 MHz…

  7. 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…

  8. Socio-Economic Aspects of National Communication Systems: II. Radio Broadcasting in Czechoslovakia. Communication and Society, 11.

    ERIC Educational Resources Information Center

    Bunzlova, Alice; Slovak, Leopold

    The second in a series that examines the role of radio broadcasting in the process of socioeconomic and cultural change in three countries with different types of broadcasting organization--Austria, Czechoslovakia, and Venezuela--this volume focuses on Czechoslovakia. It deals with the cultural implications of broadcasting structures and their…

  9. The Deep Space Network: A Radio Communications Instrument for Deep Space Exploration

    NASA Technical Reports Server (NTRS)

    Renzetti, N. A.; Stelzried, C. T.; Noreen, G. K.; Slobin, S. D.; Petty, S. M.; Trowbridge, D. L.; Donnelly, H.; Kinman, P. W.; Armstrong, J. W.; Burow, N. A.

    1983-01-01

    The primary purpose of the Deep Space Network (DSN) is to serve as a communications instrument for deep space exploration, providing communications between the spacecraft and the ground facilities. The uplink communications channel provides instructions or commands to the spacecraft. The downlink communications channel provides command verification and spacecraft engineering and science instrument payload data.

  10. 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.

  11. Educational Radio.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    This report summarizes information about the history, technology, and operation of educational radio in the U.S. Also presented are the Federal Communications Commission's (FCC) rules and regulations concerning the licensing and channel assignment of educational radio, and its auxiliary special broadcast services. Included are the application…

  12. Testing of Radio Communication Subsystems for the NUTS CubeSat on a Meteorological Balloon Flight from Andoya in 2014

    NASA Astrophysics Data System (ADS)

    Tommer, M.; Birkeland, R.; Gjersvik, A.; Stein, T. A.; Vestnes, F.; Skagmo, J. P.; Kvamtro, K. M.; Eckholdt, F.; Alstad, T.; Grande, J.; Mathisen, S. V.

    2015-09-01

    In April 2014, the Norwegian University of Science and Technology (NTNU) Test Satellite (NUTS) team carried out a balloon campaign at Andøya, Norway. The purpose was to test the on-board UHF and VHF radio prototypes. In accordance with the project mission goals, this campaign marked the test of the engineering model's communication subsystems. One of the mission requirements was that these systems should be as close to the final flight-model as possible. Parts of the system were built and assembled in advance at NTNU, and the final system integration was carried out at Andøya. A standard PTU probe with a GPS module transmitting the balloon's location in the UHF band was used to track the flight. The probe was mounted below the NUTS payload box. The payload radios was tracked using Yagi antennas based on the received GPS coordinates from the PTU probe. A two-way communication link was established and maintained between the balloon and the ground station. This paper will present the results from the mission as well as lessons learned related to the preparation and execution of balloon campaigns.

  13. CULTURAL RADIO BROADCASTS, SOME EXPERIENCES. REPORTS AND PAPERS ON MASS COMMUNICATION, NO. 23.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    CULTURAL RADIO PROGRAM DIRECTORS AND PRODUCERS DESCRIBE THE CULTURAL, ARTISTIC, SCIENTIFIC, EDUCATIONAL AND EXPERIMENTAL PROGRAMS AVAILABLE IN THEIR COUNTRIES, EXPLAINING THE VARIOUS ORGANIZATIONAL FRAMEWORKS, THE LISTENING PATTERNS AND TASTES OF THEIR PEOPLE, AND THE PROBLEMS THEY HAVE ENCOUNTERED. THESE INCLUDE PROBLEMS OF MULTIPLE LANGUAGES,…

  14. Beekeeper, Biker, and Mme le Ministre: Using Radio Recordings to Teach Culture and Communication.

    ERIC Educational Resources Information Center

    Munley, Ellen W.

    1983-01-01

    Discusses the close relationship between study of language and of culture when attention is centered on a native speaker's discourse and methods of using recordings to increase students' language skills. These perspectives are illustrated by reference to taped recordings available from Cassettes Radio France. (AMH)

  15. The Radio Communication Project in Nepal: A Culture-Centered Approach to Participation

    ERIC Educational Resources Information Center

    Dutta, Mohan Jyoti; Basnyat, Iccha

    2008-01-01

    Considerable research has been conducted on the topic of entertainment-education (EE), the method of using entertainment platforms such as popular music, radio, and television programming to diffuse information, attitudes, and behaviors via role modeling. A significant portion of the recently published EE literature has used the case of the Radio…

  16. RAPID COMMUNICATION: On the applicability of Sato's equation to capacitative radio frequency sheaths

    NASA Astrophysics Data System (ADS)

    Balakrishnan, J.; Nagabhushana, G. R.

    2000-12-01

    We show that the time-dependent version of Sato's equation, when applied to capacitative radio frequency sheaths, is no longer independent of the electric field of the space charge, and we discuss the use of the equation for a specific sheath model.

  17. "Impulsive" suicide attempts: What do we really mean?

    PubMed

    May, Alexis M; Klonsky, E David

    2016-07-01

    Suicide attempts are often regarded as impulsive acts. However, there is little consensus regarding the definition or clinical characteristics of an "impulsive" attempt. To clarify this issue, we examined 3 indicators of the impulsivity of an attempt: (a) preparation, (b) time contemplating the attempt, and (c) self-report that impulsivity motivated the attempt. We examined relationships among the indicators and their relationship to trait impulsivity and characteristics of the suicide attempt. Adult participants (N = 205) with a history of suicide attempts were administered validated interviews and questionnaires. In general, the 3 attempt impulsivity indicators correlated only moderately with each other and not at all with trait impulsivity or with important characteristics of the attempt (e.g., lethality, preattempt communication, motivations). However, there were 2 exceptions. First, intent to die was inversely related to the 3 attempt impulsivity indicators (rs ranged from -.17 to .45) such that more impulsive attempts were associated with lower intent. Second, self-report that the attempt was motivated by impulsivity was related to 3 facets of trait impulsivity (rs ranged from .16 to .41). These findings suggest that individuals endorsing trait impulsivity are likely to describe their attempts as motivated by impulsivity, regardless of the presence of preparation or prolonged contemplation. Overall, study results suggest that the common conception of a unidimensional impulsive attempt may be inaccurate and that the emphasis on general impulsivity in prevention guidelines should be tempered. Implications for suicide risk assessment and prevention are discussed. (PsycINFO Database Record PMID:26653582

  18. Subjective voice quality, communicative ability and swallowing after definitive radio(chemo)therapy, laryngectomy plus radio(chemo)therapy, or organ conservation surgery plus radio(chemo)therapy for laryngeal and hypopharyngeal cancer

    PubMed Central

    Szuecs, Marcella; Kuhnt, Thomas; Punke, Christoph; Witt, Gabriele; Klautke, Gunther; Kramp, Burkhard; Hildebrandt, Guido

    2015-01-01

    This retrospective analysis focusses on the impact of therapy on perceived long-term post-cancer treatment function. A validated questionnaire including items and components for the assessment of communicative ability, quality of voice and swallowing was sent to 129 patients. All patients were treated between 1998 and 2007. A total of 76 patients (58.9%) with carcinoma of the larynx or hypopharynx replied to the questionnaire. Data was evaluated retrospectively. Therapy delivered was definitive radio(chemo)therapy (defchRT/RT) (21/76, 28%), laryngectomy + radio(chemo)therapy (LE + chRT/RT) (28/76, 37%), or larynx conservation surgery + radio(chemo)therapy (LCS + chRT/RT) (27/76, 36%). Radiotherapy was administered using 2D- or 3D-conformal planning. The most common concomitant chemotherapy delivered was cisplatin + 5FU. For statistical analyses of the components, averages were calculated and tested using the Kruskal–Wallis test and the U-test of Mann and Whitney. Differences were assessed by the Monte Carlo method or Fisher's exact test. The single item rates were compared with Fisher's exact test. Mean follow-up was 56.7 months (range, 8–130 months). After defchRT/RT, patients trended towards more substantial–strong hoarseness compared with LCS + chRT/RT (P = 0.2). After LE, patients were dissatisfied with their artificial larynx/electrolarynx and the tone of their voice (P = 0.3, P = 0.07) and communicative ability (P = 0.005, P = 0.008) compared with those treated with defchRT/RT and LCS + chRT/RT, respectively. Dysphagia and additional percutaneous endoscopic gastrostomy (PEG) feeding were more frequent after defchRT/RT in comparison with the other two groups (P < 0.05). Voice quality and communicative ability were slightly worse after defchRT/RT and LE + chRT/RT, but satisfying with all treatment modalities. Further development of the therapy approach is necessary to reduce long-term side effects, with measures of post-treatment function as important

  19. Subjective voice quality, communicative ability and swallowing after definitive radio(chemo)therapy, laryngectomy plus radio(chemo)therapy, or organ conservation surgery plus radio(chemo)therapy for laryngeal and hypopharyngeal cancer.

    PubMed

    Szuecs, Marcella; Kuhnt, Thomas; Punke, Christoph; Witt, Gabriele; Klautke, Gunther; Kramp, Burkhard; Hildebrandt, Guido

    2015-01-01

    This retrospective analysis focusses on the impact of therapy on perceived long-term post-cancer treatment function. A validated questionnaire including items and components for the assessment of communicative ability, quality of voice and swallowing was sent to 129 patients. All patients were treated between 1998 and 2007. A total of 76 patients (58.9%) with carcinoma of the larynx or hypopharynx replied to the questionnaire. Data was evaluated retrospectively. Therapy delivered was definitive radio(chemo)therapy (defchRT/RT) (21/76, 28%), laryngectomy + radio(chemo)therapy (LE + chRT/RT) (28/76, 37%), or larynx conservation surgery + radio(chemo)therapy (LCS + chRT/RT) (27/76, 36%). Radiotherapy was administered using 2D- or 3D-conformal planning. The most common concomitant chemotherapy delivered was cisplatin + 5FU. For statistical analyses of the components, averages were calculated and tested using the Kruskal-Wallis test and the U-test of Mann and Whitney. Differences were assessed by the Monte Carlo method or Fisher's exact test. The single item rates were compared with Fisher's exact test. Mean follow-up was 56.7 months (range, 8-130 months). After defchRT/RT, patients trended towards more substantial-strong hoarseness compared with LCS + chRT/RT (P = 0.2). After LE, patients were dissatisfied with their artificial larynx/electrolarynx and the tone of their voice (P = 0.3, P = 0.07) and communicative ability (P = 0.005, P = 0.008) compared with those treated with defchRT/RT and LCS + chRT/RT, respectively. Dysphagia and additional percutaneous endoscopic gastrostomy (PEG) feeding were more frequent after defchRT/RT in comparison with the other two groups (P < 0.05). Voice quality and communicative ability were slightly worse after defchRT/RT and LE + chRT/RT, but satisfying with all treatment modalities. Further development of the therapy approach is necessary to reduce long-term side effects, with measures of post-treatment function as important endpoints

  20. Hybrid system of communication and radio determination using two geostationary satellites

    NASA Technical Reports Server (NTRS)

    Ohmori, Shingo; Matsumoto, Yasushi; Morikawa, Eihisa; Wakao, Masayoshi

    1990-01-01

    A new hybrid satellite system which can provide both communications and positioning services in one system using two geostationary satellites is discussed. The distinctive feature is that location information can be provided by transmitting and receiving ranging signals over the same channel as communications through two geostationary satellites.

  1. Task six report: Spacecraft communication terminal evaluation. [analysis of space communication at six different wavelengths in radio and optical frequency regions

    NASA Technical Reports Server (NTRS)

    1973-01-01

    An analytical comparison is made of space communication accomplished at six different wavelengths. In the radio band, 2.25, 7.5, and 14.5 GHz systems are analyzed, while at optical wavelengths, 0.53, 1.06 and 10.6 micron systems are examined. The purpose of the comparison is to determine which of these systems will require the least hardware weight to perform a given communication task. The problem is solved by requiring each communication system to meet a given performance while selecting combinations of transmitted power and antenna diameter to obtain the least overall system weight. This performance is provided while maintaining practical values for parameters other than antenna diameter and power, which also affect system performance. The results of the analysis indicate that for future data links over ranges of 42,000 to 84,000 km and with data bandwidths of 100 to 1000 MHz, the CO2 laser system will provide the required performance with the least total system weight impact on a spacecraft.

  2. Antenna Technology and other Radio Frequency (RF) Communications Activities at the Glenn Research Center in Support of NASA's Exploration Vision

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.

    2007-01-01

    NASA s Vision for Space Exploration outlines a very ambitious program for the next several decades of the Space Agency endeavors. Ahead is the completion of the International Space Station (ISS); safely flight the shuttle (STS) until 2010; develop and fly the Crew Exploration Vehicle (Orion) by no later than 2014; return to the moon by no later than 2020; extend human presence across the solar system and beyond; implement a sustainable and affordable human and robotic program; develop supporting innovative technologies, knowledge and infrastructure; and promote international and commercial participation in exploration. To achieve these goals, a series of enabling technologies must be developed or matured in a timely manner. Some of these technologies are: spacecraft RF technology (e.g., high power sources and large antennas which using surface receive arrays can get up to 1 Gbps from Mars), uplink arraying (reduce reliance on large ground-based antennas and high operation costs; single point of failure; enable greater data-rates or greater effective distance; scalable, evolvable, flexible scheduling), software define radio (i.e., reconfigurable, flexible interoperability allows for in flight updates open architecture; reduces mass, power, volume), and optical communications (high capacity communications with low mass/power required; significantly increases data rates for deep space). This presentation will discuss some of the work being performed at the NASA Glenn Research Center, Cleveland, Ohio, in antenna technology as well as other on-going RF communications efforts.

  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. Cadaveric study using radio-opaque contrast to determine arterial communication between the two bellies of gastrocnemius muscles

    PubMed Central

    Agarwal, Pawan; Gupta, K. L.; Yadav, P.; Sharma, Dhananjaya

    2016-01-01

    Introduction: Gastrocnemius muscle is a workhorse flap to cover upper third tibial defects but has a limitation in covering middle one-third tibial defects. The inferiorly based hemi gastrocnemius muscle flap can be useful for reconstruction of the middle third of the leg. The arterial communication between the gastrocnemius muscle heads has been demonstrated, the consistent location, however, was not studied in large specimens. Materials and Methods: This study was conducted on sixty specimens of gastrocnemius muscles harvested from thirty fresh cadavers to determine arterial communication between two heads of gastrocnemius muscle using radio-opaque contrast with future application of taking one head of muscle distally based for coverage of middle third defect of tibia. A total of 60 specimens were obtained from thirty fresh cadavers. In thirty specimens, medial sural artery ligated and divided and 20 ml iohexol (350) given through popliteal artery. In remaining thirty specimens lateral sural artery ligated and divided and 20 ml iohexol (350) given through popliteal artery. Digital X-rays of gastrocnemius muscle specimens were taken, and collaterals between two bellies in lower half were noted and the distance of collaterals from the muscles top edge was also noted. Results: We found the communications between both bellies of the gastrocnemius muscle in all specimens in both legs. The mean distance of communications from the upper edge of the medial belly was 15.88 cm and from upper edge of the lateral belly was 14.72 cm in the right leg, respectively. The mean distance of communications from upper edge of the medial belly was 16.01 cm and from upper edge of the lateral belly was 13.78 cm in the left leg. The distal communications between gastrocnemius bellies were not constant in their location, but all the connections were present in distal 3.79 cm of raphe. Conclusion: This study supports the future application of inferior-based hemigastrocnemius muscles flap

  5. Studying integrated silicon-lens antennas for radio communication systems operated in the 60 GHz frequency band

    NASA Astrophysics Data System (ADS)

    Artemenko, A. A.; Mal'tsev, A. A.; Maslennikov, R. O.; Sevastyanov, A. G.; Ssorin, V. N.

    2013-01-01

    We consider the development of an integrated lens antenna for LAN radio communication systems operated in the 60 GHz frequency band. The antenna is an extended hemispherical silicon lens. On its flat surface, a microstrip antenna element is located. The use of silicon, which has a dielectric permittivity ɛ = 11.7, as the lens material ensures the maximum range of scanning angles for the minimum axial size of the lens. The approximate analytical formulas, which are used for initial calculations of the lens parameters, allow one to evaluate the basic parameters of the lens antenna integrated with the microstrip antenna element. For further optimizing the parameters of the lens and the antenna element, 3D simulation of the electromagnetic-field distribution was performed. Based on its results, we have developed and manufactured extended hemispherical silicon lenses, which had radii of 6 and 12 mm. The planar microstrip antenna element was manufactured by the low temperature co-fired ceramics (LTCC) technology. The results of simulation and experimental studies of the manufactured prototypes demonstrate that the developed lens antennas has directivities of 17.6 and 23.1 dBi for lenses with radii of 6 and 12 mm, respectively. In this case, the maximum beam deflection angle is achieved, which is equal to 55°, while the permissible decrease in the directivity is no more than 6 dBi compared with the case of a non-deflected beam. The obtained results show that the developed integrated lens antennas can find applications in high-speed radio communication systems operated in the millimeter-wave range.

  6. Numerical arc segmentation algorithm for a radio conference: A software tool for communication satellite systems planning

    NASA Technical Reports Server (NTRS)

    Whyte, W. A.; Heyward, A. O.; Ponchak, D. S.; Spence, R. L.; Zuzek, J. E.

    1988-01-01

    The Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) provides a method of generating predetermined arc segments for use in the development of an allotment planning procedure to be carried out at the 1988 World Administrative Radio Conference (WARC) on the Use of the Geostationary Satellite Orbit and the Planning of Space Services Utilizing It. Through careful selection of the predetermined arc (PDA) for each administration, flexibility can be increased in terms of choice of system technical characteristics and specific orbit location while reducing the need for coordination among administrations. The NASARC software determines pairwise compatibility between all possible service areas at discrete arc locations. NASARC then exhaustively enumerates groups of administrations whose satellites can be closely located in orbit, and finds the arc segment over which each such compatible group exists. From the set of all possible compatible groupings, groups and their associated arc segments are selected using a heuristic procedure such that a PDA is identified for each administration. Various aspects of the NASARC concept and how the software accomplishes specific features of allotment planning are discussed.

  7. Micro-miniature radio frequency transmitter for communication and tracking applications

    SciTech Connect

    Crutcher, R.I.; Emery, M.S.; Falter, K.G.; Nowlin, C.H.; Rochelle, J.M.; Clonts, L.G.

    1996-12-31

    A micro-miniature radio frequency (rf) transmitter has been developed and demonstrated by the Oak Ridge National Laboratory. The objective of the rf transmitter development was to maximize the transmission distance while drastically shrinking the overall transmitter size, including antenna. Based on analysis and testing, an application-specific integrated circuit (ASIC) with a 16-GHz gallium arsenide (GaAs) oscillator and integrated on-chip antenna was designed and fabricated using microwave monolithic integrated circuit (MMIC) technology. Details of the development and the results of various field tests will be discussed. The rf transmitter is applicable to covert surveillance and tracking scenarios due to its small size of 2.2 x 2.2 mm, including the antenna. Additionally, the 16-GHz frequency is well above the operational range of consumer-grade radio scanners, providing a degree of protection from unauthorized interception. Variations of the transmitter design have been demonstrated for tracking and tagging beacons, transmission of digital data, and transmission of real-time analog video from a surveillance camera. Preliminary laboratory measurements indicate adaptability to direct-sequence spread-spectrum transmission, providing a low probability of intercept and/or detection. Concepts related to law enforcement applications will be presented.

  8. Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations

    PubMed Central

    Rowley, Jack T; Joyner, Ken H

    2012-01-01

    This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles. PMID:22377680

  9. The use of cell phones and radio communication systems to reduce delays in getting help for pregnant women in low- and middle-income countries: a scoping review

    PubMed Central

    Oyeyemi, Sunday O.; Wynn, Rolf

    2015-01-01

    Background Delays in getting medical help are important factors in the deaths of many pregnant women and unborn children in the low- and middle-income countries (LMIC). Studies have suggested that the use of cell phones and radio communication systems might reduce such delays. Objectives We review the literature regarding the impact of cell phones and radio communication systems on delays in getting medical help by pregnant women in the LMIC. Design Cochrane Library, PubMed, Maternity and Infant care (Ovid), Web of Science (ISI), and Google Scholar were searched for studies relating to the use of cell phones for maternal and child health services, supplemented with hand searches. We included studies in LMIC and in English involving the simple use of cell phones (or radio communication) to either make calls or send text messages. Results Fifteen studies met the inclusion criteria. All the studies, while of various designs, demonstrated positive contributory effects of cell phones or radio communication systems in reducing delays experienced by pregnant women in getting medical help. Conclusions While the results suggested that cell phones could contribute in reducing delays, more studies of a longer duration are needed to strengthen the finding. PMID:26362421

  10. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (79th, Anaheim, CA, August 10-13, 1996). Radio and Television Division.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    The Radio and Television section of the proceedings contains the following 13 papers: "Two Pacific Powers View the World: News on CBS and TBS Television" (Anne Cooper-Chen); "Nicholas Johnson: The Public's Defender on the Federal Communication Commission, 1966-1973" (Max V. Grubb); "News Tips, TV Viewers, and Computer Links: A Follow-Up Story"…

  11. A Study of EL2 Pilots' Radio Communication in the General Aviation Environment

    ERIC Educational Resources Information Center

    Estival, Dominique; Molesworth, Brett

    2009-01-01

    This paper reports on the preliminary stages of a project designed to investigate communication problems in General Aviation and assess the utility of language technologies as a means of mitigation. The study presented in this paper is the first of a three-part study, in which we aim to investigate the extent to which the English language…

  12. 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.

  13. Educational Radio. Information Bulletin 21-B.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    The term "Educational Radio" includes all radio stations licensed for noncommercial operation. A history of educational radio begins with the first domestic law for control of radio in general, The Radio Act of 1912. Federal Communication Commission (FCC) regulations pertaining to educational radio or "public radio" deal with channel assignments,…

  14. 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.

  15. Design, Development and Pre-Flight Testing of the Communications, Navigation, and Networking Reconfigurable Testbed (Connect) to Investigate Software Defined Radio Architecture on the International Space Station

    NASA Technical Reports Server (NTRS)

    Over, Ann P.; Barrett, Michael J.; Reinhart, Richard C.; Free, James M.; Cikanek, Harry A., III

    2011-01-01

    The Communication Navigation and Networking Reconfigurable Testbed (CoNNeCT) is a NASA-sponsored mission, which will investigate the usage of Software Defined Radios (SDRs) as a multi-function communication system for space missions. A softwaredefined radio system is a communication system in which typical components of the system (e.g., modulators) are incorporated into software. The software-defined capability allows flexibility and experimentation in different modulation, coding and other parameters to understand their effects on performance. This flexibility builds inherent redundancy and flexibility into the system for improved operational efficiency, real-time changes to space missions and enhanced reliability/redundancy. The CoNNeCT Project is a collaboration between industrial radio providers and NASA. The industrial radio providers are providing the SDRs and NASA is designing, building and testing the entire flight system. The flight system will be integrated on the Express Logistics Carrier (ELC) on the International Space Station (ISS) after launch on the H-IIB Transfer Vehicle in 2012. This paper provides an overview of the technology research objectives, payload description, design challenges and pre-flight testing results.

  16. Ultra Low Power, Radiation Tolerant UHF Radio Technologies for In Situ Communication Applications

    NASA Technical Reports Server (NTRS)

    Lay, N. E.

    2001-01-01

    For future deep space missions, significant reductions in the mass and power requirements for short-range telecommunication systems will be critical in enabling a wide variety of new mission concepts. These possibilities include penetrators, gliders, miniature rovers, and sensor networks. Under joint funding from NASA's Cross Enterprise and JPL's Telecommunications and Mission technology programs, recent development activity has focused on the design of ultralow mass and power transceiver systems and subsystems suitable for operation in a flight environment. For these efforts, the functionality of the transceiver has been targeted towards a specific Mars communications scenario. However, the overall architecture is well suited to any short or medium range application where a remote probe will aperiodically communicate with a base station, possibly an orbiter, for the eventual purpose of relaying science information back to Earth. In 2001, these sponsors have been augmented with collaborative expertise and funding from JPL's Center for Integrated Space Microsystems in order to migrate existing concepts and designs to a System on a Chip (SOAC) solution. Additional information is contained in the original extended abstract.

  17. Radio Frequency (RF) Micro-Electromechanical Systems (MEMS) Switches for Space Communications

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Ponchak, George E.; Scardelletti, Maximillian C.; Varaljay, Nicholas C.

    2000-01-01

    Micro-electromechanical systems (MEMS) is an emerging technology for radio frequency (RF) systems because it has the potential to dramatically decrease loss and improve efficiency. In this paper, we address the design and fabrication of novel MEMS switches being developed at NASA Glenn Research Center. Two types of switches are being developed: a microstrip series single pole single throw (SPST) switch and a coplanar waveguide (CPW) series SPST and single pole double throw (SPDT) switches. These are being fabricated as an integral part of 50 Ohm microstrip and CPW RF integrated circuits using microfabrication techniques. The construction of the switch relies on a cantilever beam that is partially supported by a dielectric post. The cantilever beam is electro-magnetically actuated. To decrease stiction, a Si3N4 thin film is deposited over the contact area. Thus, when the switch is closed, the ON-state insertion loss is governed by the parallel plate capacitance formed by the two contacts. The isolation in the OFF-state is governed by the parasitic capacitance when the cantilever is in the up position. RF MEMS switches have been demonstrated with 80% lower insertion loss than conventional solid state devices (GaAs Metal Semiconductor Field Effect Transistors (MESFETs) and Silicon PIN diodes) based switches. For example, a conventional GaAs five-bit phase shifter which is required for beam steering in a phased array antenna has approximately 7 dB of insertion loss at 26.5 GHz where as a comparable MEMS based phase shifter is expected to have only 2 dB of insertion loss. This translates into 56% lower power dissipation and therefore decreases the thermal load on the spacecraft and also reduces the power amplifier requirements. These benefits will enable NASA to build the next generation of deep space science crafts and micro/nano satellites.

  18. Behavioral components of impulsivity.

    PubMed

    Stahl, Christoph; Voss, Andreas; Schmitz, Florian; Nuszbaum, Mandy; Tüscher, Oliver; Lieb, Klaus; Klauer, Karl Christoph

    2014-04-01

    Acting in accord with long-term goals requires control of interfering impulses, the success of which depends on several different processes. Using a structural-equation modeling approach, we investigated 5 behavioral components of impulsivity: the control of stimulus interference, proactive interference, and response interference, as well as decisional and motivational impulsivity. Results support the existence of 5 correlated but separable components of impulsive behavior. The present study is the 1st to demonstrate the separability of stimulus and response interference. It also supports the notion that control of response-related interference is not a unitary construct: Response-selection demands were separable from those of withholding or stopping. Relations between behavioral impulsivity components and self-report measures of impulsivity were largely absent. We conclude that as the construct of impulsivity has been extended to describe an increasingly diverse set of phenomena and processes, it has become too broad to be helpful in guiding future research. PMID:23957282

  19. Genetics of impulsive behaviour

    PubMed Central

    Bevilacqua, Laura; Goldman, David

    2013-01-01

    Impulsivity, defined as the tendency to act without foresight, comprises a multitude of constructs and is associated with a variety of psychiatric disorders. Dissecting different aspects of impulsive behaviour and relating these to specific neurobiological circuits would improve our understanding of the etiology of complex behaviours for which impulsivity is key, and advance genetic studies in this behavioural domain. In this review, we will discuss the heritability of some impulsivity constructs and their possible use as endophenotypes (heritable, disease-associated intermediate phenotypes). Several functional genetic variants associated with impulsive behaviour have been identified by the candidate gene approach and re-sequencing, and whole genome strategies can be implemented for discovery of novel rare and common alleles influencing impulsivity. Via deep sequencing an uncommon HTR2B stop codon, common in one population, was discovered, with implications for understanding impulsive behaviour in both humans and rodents and for future gene discovery. PMID:23440466

  20. [Risk of noise-induced hearing loss caused by radio communication? Audiologic findings in helicopter crews and pilots of propeller airplanes].

    PubMed

    Matschke, R G

    1987-12-01

    The affects of noise on the human inner ear have been well known for a long time, and measures to prevent occupational noise-induced hearing loss show a clear reduction in the statistics of morbidity. Nevertheless, there are working environments in which the use of ear protection seems to be inapplicable, because communication by speech is indispensable, for example in the cockpit of aircraft. Noise exposure measurements were performed on pilots of helicopters and propeller-machines of the German Federal Navy during realistic flight situations. The ambient noise levels during regular flight service were maintained at levels between 89 dB and 120 dB. Sound protection by flight-helmets and headphones is not only neutralised while using radio and intercom, but the noise during radio-communication is even louder than the noise of the engines. The use of ear protection to avoid excessive noise exposure is only of limited effectiveness. While pilots with normal hearing show only little impairment of speech intelligibility, those with noise-induced hearing loss show substantial impairment that varies in proportion to their hearing loss. Communication abilities may be drastically reduced which may compromise the reliability of radio-communication. The problem may be possibly solved in future by an electronic compensation system for noise. PMID:3429278

  1. Radio frequency fields generated by the S-band communication link on OV102

    NASA Technical Reports Server (NTRS)

    Murphy, G. B.; Shawhan, S. D.

    1984-01-01

    The Space Shuttle STS-3 mission carried a Plasma Diagnostics Package (PDP) whose instrumentation included an S-band antenna and detector. The PDP was maneuvered by the Remote Manipulator System arm through a computer controlled sequence in the Orbiter's X-Z plane, above the quad and hemi S-band communications antennas. Antenna field strength measurements were conducted during transmitter high power modes, and the results were compared to ground full scale measurements and predictions. A field strength 4.8 + or - 3 dB higher than predicted is noted. This RF field is primarily due to the quad PM transmitter, whose power output of 115 W compares with 15 W for the hemi.

  2. An implementation of Software Defined Radios for federated aerospace networks: Informing satellite implementations using an inter-balloon communications experiment

    NASA Astrophysics Data System (ADS)

    Akhtyamov, Rustam; Cruz, Ignasi Lluch i.; Matevosyan, Hripsime; Knoll, Dominik; Pica, Udrivolf; Lisi, Marco; Golkar, Alessandro

    2016-06-01

    Novel space mission concepts such as Federated Satellite Systems promise to enhance sustainability, robustness, and reliability of current missions by means of in-orbit sharing of space assets. This new paradigm requires the utilization of several technologies in order to confer flexibility and re-configurability to communications systems among heterogeneous spacecrafts. This paper illustrates the results of the experimental demonstration of the value proposition of federated satellites through two stratospheric balloons interoperating with a tracking ground station through Commercial Off-The-Shelf Software Defined Radios (SDRs). The paper reports telemetry analysis and characterizes the communications network that was realized in-flight. Furthermore, it provides details on an in-flight anomaly experienced by one of the balloons, which was recovered through the use of the federated technology that has been developed. The anomaly experienced led to the early loss of the directional link from the ground station to the affected stratospheric balloon node after 15 min in flight. Nevertheless, thanks to the federated approach among the systems, the ground station was still able to retrieve the balloon's data in real time through the network system, for which the other balloon operated as a federated relay for 45 min in flight, uninterrupted. In other words, the federated approach to the system allowed triplicating the useful lifetime of the defective system, which would have not been possible to realize otherwise. Such anomaly coincidentally demonstrated the value of the federated approach to space systems design. The paper paves the way for future tests on space assets.

  3. [Effects of radio- and microwaves emitted by wireless communication devices on the functions of the nervous system selected elements].

    PubMed

    Politański, Piotr; Bortkiewicz, Alicja; Zmyślony, Marek

    2016-01-01

    Nervous system is the most "electric" system in the human body. The research of the effects of electromagnetic fields (EMFs) of different frequencies on its functioning have been carried out for years. This paper presents the results of the scientific literature review on the EMF influence on the functioning of the human nervous system with a particular emphasis on the recent studies of the modern wireless communication and data transmission systems. In the majority of the analyzed areas the published research results do not show EMF effects on the nervous system, except for the influence of GSM telephony signal on resting EEG and EEG during patients' sleep and the influence of radiofrequency EMF on the cardiovascular regulation. In other analyzed areas (EMF impact on sleep, the evoked potentials and cognitive processes), there are no consistent results supporting any influence of electromagnetic fields. Neurophysiological studies of the effect of radio- and microwaves on the brain functions in humans are still considered inconclusive. This is among others due to, different exposure conditions, a large number of variables tested, deficiencies in repeatability of research and statistical uncertainties. However, methodological guidelines are already available giving a chance of unifying research that definitely needs to be continued in order to identify biophysical mechanisms of interaction between EMFs and the nervous system. One of the EMF research aspects, on which more and more attention is paid, are inter-individual differences. Med Pr 2016;67(3):411-421. PMID:27364114

  4. Impulsive action: emotional impulses and their control

    PubMed Central

    Frijda, Nico H.; Ridderinkhof, K. Richard; Rietveld, Erik

    2014-01-01

    This paper presents a novel theoretical view on impulsive action, integrating thus far separate perspectives on non-reflective action, motivation, emotion regulation, and impulse control. We frame impulsive action in terms of directedness of the individual organism toward, away, or against other givens – toward future states and away from one’s present state. First, appraisal of a perceived or thought-of event or object on occasion, rapidly and without premonition or conscious deliberation, triggers a motive to modify one’s relation to that event or object. Situational specifics of the event as perceived and appraised motivate and guide selection of readiness for a particular kind of purposive action. Second, perception of complex situations can give rise to multiple appraisals, multiple motives, and multiple simultaneous changes in action readiness. Multiple states of action readiness may interact in generating action, by reinforcing or attenuating each other, thereby yielding impulse control. We show how emotion control can itself result from a motive state or state of action readiness. Our view links impulsive action mechanistically to states of action readiness, which is the central feature of what distinguishes one kind of emotion from another. It thus provides a novel theoretical perspective to the somewhat fragmented literature on impulsive action. PMID:24917835

  5. A new wideband HF technique for MHz-bandwidth spread-spectrum radio communications

    NASA Astrophysics Data System (ADS)

    Perry, B. D.

    1983-09-01

    The one-way results are seen as demonstrating that equalized MHz-bandwidth skywave HF channels can be achieved using long-range one-hop F-layer propagation paths. It has thus become possible to use direct-sequence pseudo-noise or coherent fast-frequency-hop signaling at HF with processing gains of several orders of magnitude for teletype data rates. Possibilities are seen for using the spread spectrum in covert and/or jam-resistant communications. What is more, the equalized wideband HF channel is not subject to the fading caused by multiple propagation modes; as a consequence, it is substantially more reliable than the traditional narrow-band HF channel. Conversely, reliability comparable to traditional HF can be attained at greatly reduced signal margins. Since the time stability of the wideband HF channel is of the order of 10 s, very little channel-transmission time is needed for initializing and maintaining the equalizer. It is noted that probe signals similar to the channel-measuring waveform described here or spread-spectrum training sequences at the beginning of each message are adequate. Results from the 1982 two-way experimentation show that N(omega) is not reciprocal between terminals 2000 km apart.

  6. Communication.

    ERIC Educational Resources Information Center

    Strauss, Andre

    The following essays on communication are presented: communication as a condition of survival, communication for special purposes, the means of transmission of communication, communication within social and economic structures, the teaching of communication through the press, the teaching of modern languages, communication as a point of departure,…

  7. Dealing with Impulsivity.

    ERIC Educational Resources Information Center

    Neidhardt, Janet

    1987-01-01

    A mother recounts her neurologically impaired son's struggles and progress in combating impulsivity in his work and social habits. Now 23 years old, employed full-time, and off medication, the son is still impulsive, has problems with social skills, but has improved his self-image through a photography hobby. (CB)

  8. Impulsiveness in professional fighters.

    PubMed

    Banks, Sarah J; Mayer, Brittany; Obuchowski, Nancy; Shin, Wanyong; Lowe, Mark; Phillips, Michael; Modic, Michael; Bernick, Charles

    2014-01-01

    Sports involving repeated head trauma are associated with risk of neurodegenerative disorders such as chronic traumatic encephalopathy (CTE). Among the behavioral manifestations of CTE is increased impulsiveness. Here, the authors investigate the relationship between impulsiveness and exposure to head trauma in a large group of active professional fighters. Fighters tended to report less impulsiveness than did non-fighting control respondents. Overall, greater fight exposure was associated with higher levels of a specific form of impulsiveness, although there were differences between mixed martial arts fighters and boxers. Fight exposure was associated with reduction in volume of certain brain structures, and these changes were also associated with impulsiveness patterns. Longitudinal studies of professional fighters are important to understand the risk for neuropsychiatric problems. PMID:24515676

  9. 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…

  10. 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…

  11. Communications via the radio artificial earth satellite: Design of the tracking diagram and features for conducting QSO

    NASA Technical Reports Server (NTRS)

    Dobrozhanskiy, V.; Rybkin, V.

    1980-01-01

    A detailed examination is made of the operation of a transmitting artifical Earth satellite. A tracking diagram for the satellite is constructed. The zone of radio visibility can be determined based on the techniques proposed.

  12. An orbital angular momentum radio communication system optimized by intensity controlled masks effectively: Theoretical design and experimental verification

    NASA Astrophysics Data System (ADS)

    Gao, Xinlu; Huang, Shanguo; Wei, Yongfeng; Zhai, Wensheng; Xu, Wenjing; Yin, Shan; Zhou, Jing; Gu, Wanyi

    2014-12-01

    A system of generating and receiving orbital angular momentum (OAM) radio beams, which are collectively formed by two circular array antennas (CAAs) and effectively optimized by two intensity controlled masks, is proposed and experimentally investigated. The scheme is effective in blocking of the unwanted OAM modes and enhancing the power of received radio signals, which results in the capacity gain of system and extended transmission distance of the OAM radio beams. The operation principle of the intensity controlled masks, which can be regarded as both collimator and filter, is feasible and simple to realize. Numerical simulations of intensity and phase distributions at each key cross-sectional plane of the radio beams demonstrate the collimated results. The experimental results match well with the theoretical analysis and the receive distance of the OAM radio beam at radio frequency (RF) 20 GHz is extended up to 200 times of the wavelength of the RF signals, the measured distance is 5 times of the original measured distance. The presented proof-of-concept experiment demonstrates the feasibility of the system.

  13. An orbital angular momentum radio communication system optimized by intensity controlled masks effectively: Theoretical design and experimental verification

    SciTech Connect

    Gao, Xinlu; Huang, Shanguo Wei, Yongfeng; Zhai, Wensheng; Xu, Wenjing; Yin, Shan; Gu, Wanyi; Zhou, Jing

    2014-12-15

    A system of generating and receiving orbital angular momentum (OAM) radio beams, which are collectively formed by two circular array antennas (CAAs) and effectively optimized by two intensity controlled masks, is proposed and experimentally investigated. The scheme is effective in blocking of the unwanted OAM modes and enhancing the power of received radio signals, which results in the capacity gain of system and extended transmission distance of the OAM radio beams. The operation principle of the intensity controlled masks, which can be regarded as both collimator and filter, is feasible and simple to realize. Numerical simulations of intensity and phase distributions at each key cross-sectional plane of the radio beams demonstrate the collimated results. The experimental results match well with the theoretical analysis and the receive distance of the OAM radio beam at radio frequency (RF) 20 GHz is extended up to 200 times of the wavelength of the RF signals, the measured distance is 5 times of the original measured distance. The presented proof-of-concept experiment demonstrates the feasibility of the system.

  14. Cognitive Wireless Communications - A paradigm shift in dealing with radio resources as a prerequisite for the wireless network of the future - An overview on the topic of cognitive wireless technologies

    NASA Astrophysics Data System (ADS)

    Haustein, Thomas; Stanczak, Slawomir; Wolisz, Adam; Jondral, Friedrich; Schotten, Hans; Kraemer, Rolf; Mück, Markus; Mennenga, Horst; Bender, Paul

    2016-07-01

    Wireless radio communications systems form the basis for mobile network connections in the digital society. A limited amount of radio spectrum and a spatially densified use of wireless communications systems require a resource-efficient use of the spectrum. Mechanisms of cognitive radio may hold the key to a more efficient use of the available spectrum under consideration of quality of service requirements. These mechanisms take advantage of location-specific knowledge of the wireless channel occupation in the dimensions of frequency, time, location and direction in space and therefore enable co-existent and reliable wireless communication. The authors give an introduction to the status of cognitive wireless communication technology, which represents the starting point of a series of research projects promoted by BMBF during 2012-2014.

  15. Impulsivity and methamphetamine use.

    PubMed

    Semple, Shirley J; Zians, Jim; Grant, Igor; Patterson, Thomas L

    2005-09-01

    The purpose of this study was to explore the relationship between methamphetamine (meth) use and impulsivity in a sample of 385 HIV-negative heterosexually identified meth users. Participants who scored highest on a self-report measure of impulsivity were compared with those who scored lower in terms of background characteristics, meth use patterns, use of alcohol and other illicit drugs, sexual risk behavior, and psychiatric health variables. Methamphetamine users in the high impulsivity group were younger, less educated, used larger quantities of meth, were more likely to be binge users, had a larger number of sexual partners, engaged in more unprotected vaginal and oral sex, and scored higher on the Beck Depression Inventory as compared with those in the low impulsivity group. In a logistic regression analysis, Beck depression was the factor that best distinguished between meth users who scored high and those who scored low on impulsivity. Neurophysiological pathways that may underlie the relationship between impulsivity and meth use are discussed. PMID:16135337

  16. Auto-programmable impulse neural circuits

    NASA Technical Reports Server (NTRS)

    Watula, D.; Meador, J.

    1990-01-01

    Impulse neural networks use pulse trains to communicate neuron activation levels. Impulse neural circuits emulate natural neurons at a more detailed level than that typically employed by contemporary neural network implementation methods. An impulse neural circuit which realizes short term memory dynamics is presented. The operation of that circuit is then characterized in terms of pulse frequency modulated signals. Both fixed and programmable synapse circuits for realizing long term memory are also described. The implementation of a simple and useful unsupervised learning law is then presented. The implementation of a differential Hebbian learning rule for a specific mean-frequency signal interpretation is shown to have a straightforward implementation using digital combinational logic with a variation of a previously developed programmable synapse circuit. This circuit is expected to be exploited for simple and straightforward implementation of future auto-adaptive neural circuits.

  17. 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)

  18. Solar impulsive energetic electron events

    NASA Astrophysics Data System (ADS)

    Wang, Linghua

    The Sun is capable of accelerating ions from ~ tens of keV up to tens of GeV and electrons from ~ tens of eV up to hundreds of MeVs in transient events such as flares and fast coronal mass ejections (CMEs). The energized particles escaping into the interplanetary medium are referred to as Solar Energetic Particle (SEP) events. The great majority of SEP events are impulsive SEP events that are dominated by ~1-100 keV electrons and ~MeV/nucleon ion emissions, with enhanced 3 He/ 4 He ratios up to 10 4 times the coronal values (also called electron/ 3 He-rich SEP events). This thesis is focused on solar impulsive energetic electron events, the electron part of impulsive SEP events, using electron observations from the 3-D Plasma and Energetic Particle instrument (3DP) on the WIND spacecraft near the Earth. First, I present the first comprehensive statistical study of solar energetic electron events over almost one solar cycle. I find that the occurrence rate of solar electron events shows a strong solar-cycle variation; after correction for the background effect, the estimated occurrence frequency exhibits a good power-law distribution, and the estimated occurrence rate near the Earth is ~1000/year at solar maximum and ~30/year at solar minimum for the instrumental sensitivity (~2.9×10^-4 (cm 2 s str eV) -1 for the 40 keV channel) of WIND/3DP, about one order of magnitude larger than the observed occurrence rate. Solar energetic electron events have a one-to-one association with type III radio bursts and a poor association with flares, but a close association with 3 He- rich ion emissions. These 3 He-rich electron events also have a poor association with flares but a close (~ 60%) association with west-limb CMEs. Then I present two case studies: one investigating the temporal relationship between solar impulsive electrons and type III radio emissions, and the second studying the temporal relationship between solar impulsive electrons and 3 He- rich ions. For both

  19. Signal processing in impulsive electromagnetic interference

    NASA Astrophysics Data System (ADS)

    Zabin, Serena M.

    1993-06-01

    Statistical signal processing functions such as signal detection, estimation, and identification play a key role in the development of effective communications, radar, and sonar systems. For example, advanced statistical methods are emerging as being particularly important in digital communications systems operating in channels corrupted by interference from such phenomena as multiple-access noise, intentional jamming, and impulsive noise sources. Conventional demodulation methods, such as coherent matched filtering, often suffer serious performance degradation when subject to interference of these types; however, this degradation can frequently be eliminated through the use of more sophisticated signal processing techniques. During this reporting period, the focus of our work has been on the problem of obtaining optimum and efficient identification and detection procedures for impulsive channels. Of particular interest is the Middleton Class A noise model, which is a widely-accepted statistical-physical model for impulsive interference superimposed on a Gaussian background. The model has two basic parameters that can be adjusted to fit a wide variety of impulsive noise phenomena occurring in practice.

  20. Communications

    NASA Technical Reports Server (NTRS)

    Stouffer, Donald D.

    1990-01-01

    Communication in its many forms is a critical component for an effective Space Grant Program. Good communication is needed within individual Space Grant College/Consortia, for example between consortium affiliates and the consortium program office. Effective communication between the several programs, NASA Headquarters, and NASA field centers also is required. Further, communication among the above program elements, industry, local and state government, and the public also are necessary for meeting program objectives.

  1. The Possibility of Increasing the Throughput of a High-Frequency Radio-Communication Channel Using a Mimo System

    NASA Astrophysics Data System (ADS)

    Metelev, S. A.

    2014-09-01

    We consider the possibility of increasing the radio-channel throughput in the high-frequency range by using antenna arrays. The MIMO-system efficiency is studied with the help of the modified Watterson model by the simulation method. The signal parameters for which the MIMO processing yields the best results are determined.

  2. Optically measured explosive impulse

    NASA Astrophysics Data System (ADS)

    Biss, Matthew M.; McNesby, Kevin L.

    2014-06-01

    An experimental technique is investigated to optically measure the explosive impulse produced by laboratory-scale spherical charges detonated in air. Explosive impulse has historically been calculated from temporal pressure measurements obtained via piezoelectric transducers. The presented technique instead combines schlieren flow visualization and high-speed digital imaging to optically measure explosive impulse. Prior to an explosive event, schlieren system calibration is performed using known light-ray refractions and resulting digital image intensities. Explosive charges are detonated in the test section of a schlieren system and imaged by a high-speed digital camera in pseudo-streak mode. Spatiotemporal schlieren intensity maps are converted using an Abel deconvolution, Rankine-Hugoniot jump equations, ideal gas law, triangular temperature decay profile, and Schardin's standard photometric technique to yield spatiotemporal pressure maps. Temporal integration of individual pixel pressure profiles over the positive pressure duration of the shock wave yields the explosive impulse generated for a given radial standoff. Calculated explosive impulses are shown to exhibit good agreement between optically derived values and pencil gage pressure transducers.

  3. Impulse-Momentum Diagrams

    NASA Astrophysics Data System (ADS)

    Rosengrant, David

    2011-01-01

    Multiple representations are a valuable tool to help students learn and understand physics concepts. Furthermore, representations help students learn how to think and act like real scientists.2 These representations include: pictures, free-body diagrams,3 energy bar charts,4 electrical circuits, and, more recently, computer simulations and animations.5 However, instructors have limited choices when they want to help their students understand impulse and momentum. One of the only available options is the impulse-momentum bar chart.6 The bar charts can effectively show the magnitude of the momentum as well as help students understand conservation of momentum, but they do not easily show the actual direction. This paper highlights a new representation instructors can use to help their students with momentum and impulse—the impulse-momentum diagram (IMD).

  4. Ballistic impulse gauge

    DOEpatents

    Ault, Stanley K.

    1993-01-01

    A gauge for detecting the impulse generated in sample materials by X-rays or other impulse producing mechanisms utilizes a pair of flat annular springs to support a plunger relative to a housing which may itself be supported by a pair of flat annular springs in a second housing. The plunger has a mounting plate mounted on one end and at the other, a position or velocity transducer is mounted. The annular springs consist of an outer ring and an inner ring with at least three arcuate members connecting the outer ring with the inner ring.

  5. Ballistic impulse gauge

    DOEpatents

    Ault, S.K.

    1993-12-21

    A gauge for detecting the impulse generated in sample materials by X-rays or other impulse producing mechanisms utilizes a pair of flat annular springs to support a plunger relative to a housing which may itself be supported by a pair of flat annular springs in a second housing. The plunger has a mounting plate mounted on one end and at the other, a position or velocity transducer is mounted. The annular springs consist of an outer ring and an inner ring with at least three arcuate members connecting the outer ring with the inner ring. 4 figures.

  6. Integrating systems theory and attachment theory: the use of radio communication to modify attachments in a patient with psychogenic vomiting.

    PubMed

    Dickman, D; Prieto, P

    1987-10-01

    A case is presented that shows the usefulness of integrating systems theory and attachment theory in the formulation and treatment of a clinical problem. The 5 year old son of East Indian immigrants presented with persistent psychogenic vomiting associated with pathological family attachments. It was evident that the precarious family equilibrium was stabilized by the child's psychogenic vomiting. The therapeutic team suggested to the family that their problems might be more satisfactorily resolved if the mother and child maintained their link by two-way radio. Three weeks later the vomiting had ceased, the child no longer felt that he needed the radio and both parents had established new patterns of relating to their child, whose attendance and peer socialization at school showed marked improvement. To some extent the rapid resolution of the problems was facilitated by the cultural strengths of the family. PMID:3676993

  7. Unmanned Aviation Systems Models of the Radio Communications Links: Study Results - Appendices Annex 2. Volume 1 and Volume 2

    NASA Technical Reports Server (NTRS)

    Birr, Richard B.; Spencer, Roy; Murray, Jennifer; Lash, Andrew

    2013-01-01

    This report describes the analysis of communications between the Control Station and an Unmanned Aircraft (UA) flying in the National Airspace System (NAS). This work is based on the RTCA SC-203 Operational Services and Environment Description (OSED). The OSED document seeks to characterize the highly different attributes of all UAs navigating the airspace and define their relationship to airspace users, air traffic services, and operating environments of the NAS. One goal of this report is to lead to the development of Minimum Aviation System Performance Standards for Control and Communications. This report takes the nine scenarios found in the OSED and analyzes the communication links.

  8. 78 FR 26739 - Radio Broadcasting Services; Ehrenberg, Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-08

    ... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Ehrenberg, Arizona AGENCY: Federal Communications... Subjects in 47 CFR Part 73 Radio, Radio broadcasting. Federal Communications Commission. Nazifa Sawez... Communications Commission proposes to amend 47 CFR Part 73 as follows: PART 73--RADIO BROADCAST SERVICES 0 1....

  9. 77 FR 23203 - Radio Broadcasting Services; Summit, MS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Summit, MS AGENCY: Federal Communications Commission... Subjects in 47 CFR Part 73 Radio, Radio broadcasting. Federal Communications Commission. Nazifa Sawez... Communications Commission proposes to amend 47 CFR Part 73 as follows: PART 73--RADIO BROADCAST SERVICES 1....

  10. 76 FR 67397 - Radio Broadcasting Services; Llano, Texas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Llano, Texas AGENCY: Federal Communications Commission... 47 CFR Part 73 Radio, Radio broadcasting. Federal Communications Commission. Nazifa Sawez, Assistant... Communications Commission proposes to amend 47 CFR part 73 as follows: PART 73--RADIO BROADCAST SERVICES 1....