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Sample records for jth radio transmitter

  1. Opportunistic transmitter selection for selfless overlay cognitive radios

    KAUST Repository

    Shaqfeh, Mohammad

    2013-11-01

    We propose an opportunistic strategy to grant channel access to the primary and secondary transmitters in causal selfless overlay cognitive radios over block-fading channels. The secondary transmitter helps the primary transmitter by relaying the primary messages opportunistically, aided by a buffer to store the primary messages temporarily. The optimal channel-aware transmitter- selection strategy is the solution of the maximization of the average secondary rate under the average primary rate requirement and the buffer stability constraints. Numerical results demonstrate the gains of the proposed opportunistic selection strategy. © 2013 IEEE.

  2. Solar radio-transmitters on snail kites in Florida

    Science.gov (United States)

    Snyder, N.F.R.; Beissinger, S.R.; Fuller, M.R.

    1989-01-01

    The effectiveness and safety of one- and two-stage solar radio-transmitters in tracking the movements and survival of adult and fledgling Snail Kites (Rostrhamus sociabilis) were evaluated between 1979 and 1983 in southern Florida. Transmitters were attached to birds with back-pack arrangements using teflon ribbon straps. Accessory plastic shields minimized feather coverage of the solar cells. Intact transmitters were seen on birds up to 47 mo after installation. Operating lives ranged from 8 to 21 mo for one-stage, and 10 to 14 mo for two-stage transmitters. Because survival of adult and nestling radio-marked kites was high, we conclude that our transmitter-attachment method had little effect on the birds.

  3. Effects of radio transmitters on migrating wood thrushes

    Science.gov (United States)

    Powell, L.A.; Krementz, D.G.; Lang, J.D.; Conroy, M.J.

    1998-01-01

    We quantified the effects of radio transmitters on Wood Thrushes (Hylocichla mustelina) using 4 yr of banding and telemetry data from Piedmont National Wildlife Refuge, Georgia. Flight performance models suggest that the 1.6-g transmitter shortens the migratory range of Wood Thrushes by only 60 km, and the estimated migratory range is adequate to accomplish migration even with limited fat stores. We used two strengths of line, 5- and 9-kg test-strength braided Dacron, to attach the transmitters using the thigh-harness method. We recaptured 13 returning radio-marked Wood Thrushes, seven of which were still marked. Six of the seven birds marked with the 5-kg test harnesses lost their transmitters within 1 yr while all six of the 9-kg test harnesses were still attached up to 21 mo later. Radio-marking did not reduce the return rates of adults and immatures, and the transmitters did not cause radio-marked birds to lose more mass than banded-only birds. Wood Thrushes can successfully carry a transmitter during migration with no detectable negative effects. We recommend continued use of the thigh-harness method, but we encourage the use of 5-kg cotton line.

  4. Effects of radio transmitters on nesting captive mallards

    Science.gov (United States)

    Houston, Robert A.; Greenwood, Raymond J.

    1993-01-01

    Radio packages may subtly affect bird behavior and condition, and thus could bias results from studies using this technique. To assess effects on reproduction of mallards (Anas platyrhynchos), we tested 3 types of back-mounted radio packages on captive females. Eight paired females were randomly assigned to each of 4 treatments: 4-g transmitter attached with sutures and glue, 10-g or 18-g transmitter attached with a harness, and no transmitter (control). All mallards were fed ad libitum. No differences were detected among treatments in number of clutches, clutch size, nesting interval, egg mass, or body mass; powers (range = 0.15-0.48) of tests were low. Feather wear and skin irritation around radio packages were minimal. Birds retained sutured transmitters for an average of 43.5 days (range = 3-106 days) and harness transmitters for the duration of the study (106 days). Sutures were not reliable and presently are not recommended as an attachment method. Caution is advised in applying these results to radio-equipped mallards in the wild.

  5. Snake mortality associated with late season radio-transmitter implantation

    Science.gov (United States)

    D. Craig Rudolph; Shirley J. Burgdorf; Richard R. Schaefer; Richard N. Conner; Robert T. Zappalorth

    1998-01-01

    Radio-telemetry is an increasingly used procedure to obtain data on the biology of free-living snakes (Reinert 1992, 1994). In Texas and Louisiana we have been using the surgical technique of Weatherhead and Anderka (1984) to implant transmitters in timber rattlesnakes (Crotalus horridus) and Louisiana pine snakes (Pituophis melanoleucus...

  6. Optimisation of radio transmitter locations in mobile telecommunications networks

    Directory of Open Access Journals (Sweden)

    Schmidt-Dumont, Thorsten

    2016-08-01

    Full Text Available Multiple factors have to be taken into account when mobile telecommunication network providers make decisions about radio transmitter placement. Generally, area coverage and the average signal level provided are of prime importance in these decisions. These criteria give rise to a bi-objective problem of facility location, with the goal of achieving an acceptable trade-off between maximising the total area coverage and maximising the average signal level provided to the demand region by a network of radio transmitters. This paper establishes a mathematical modelling framework, based on these two placement criteria, for evaluating the effectiveness of a given set of radio transmitter locations. In the framework, coverage is measured according to the degree of obstruction of the so-called ‘Fresnel zone’ that is formed between handset and base station, while signal strength is modelled taking radio wave propagation loss into account. This framework is used to formulate a novel bi-objective facility location model that may form the basis for decision support aimed at identifying high-quality transmitter location trade-off solutions for mobile telecommunication network providers. But it may also find application in various other contexts (such as radar, watchtower, or surveillance camera placement optimisation.

  7. Effects of implanted radio transmitters with percutaneous antennas on the behavior of Canada Geese

    Science.gov (United States)

    Hupp, J.W.; Ruhl, G.A.; Pearce, J.M.; Mulcahy, D.M.; Tomeo, M.A.

    2003-01-01

    We examined whether surgically-implanted radio transmitters with percutaneous antennas affected behavior of Lesser Canada Geese (Branta canadensis parvipes) in Anchorage, Alaska. We implanted either a 26-g VHF radio transmitter or a larger VHF radio that was the same mass (35 g) and shape as a satellite transmitter in the coelom of adult females captured during molt in 2000. A control group of females was marked with leg bands. We simultaneously observed behavior of radio-marked and control females from 4-62 d following capture. We observed no differences in the proportion of time birds in different treatments allocated among grazing, resting, comfort, walking, and alert behavior. Females in different treatments spent a similar proportion of time in the water. Implantation of radio transmitters did not affect the frequency of agonistic interactions. We conclude that coelomic radio transmitters with percutaneous antennas had minimal effects on the behavior of Canada Geese.

  8. Software-Defined Radio Global System for Mobile Communications Transmitter Development for Heterogeneous Network Vulnerability Testing

    Science.gov (United States)

    2013-12-01

    48  3.  Results .................................................................................................48  a.  GNU Radio ...56  b.  GNU Radio Collection...by GNU Radio of the baseband signal created by the GSM transmitter code mimicking the GSM BTS BCH prior to USRP transmission. The blue signal shows

  9. Broadband Radio Service (BRS) and Educational Broadband Service (EBS) Transmitters

    Data.gov (United States)

    Department of Homeland Security — The Broadband Radio Service (BRS), formerly known as the Multipoint Distribution Service (MDS)/Multichannel Multipoint Distribution Service (MMDS), is a commercial...

  10. Effects of radio transmitters on the behavior of Red-headed Woodpeckers.

    Energy Technology Data Exchange (ETDEWEB)

    Vukovich, Mark; Kilgo, John, C.

    2009-05-01

    ABSTRACT. Previous studies have revealed that radio-transmitters may affect bird behaviors, including feeding rates, foraging behavior, vigilance, and preening behavior. In addition, depending on the method of attachment, transmitters can potentially affect the ability of cavity-nesting birds to use cavities. Our objective was to evaluate effects of transmitters on the behavior of and use of cavities byRed-headedWoodpeckers (Melanerpes erythrocephalus). Using backpack harnesses, we attached 2.1-g transmitter packages that averaged 3.1% of body weight (range = 2.5–3.6%) to Red-headed Woodpeckers. We observed both radio-tagged (N = 23) and nonradio-tagged (N = 28) woodpeckers and determined the percentage of time spent engaged in each of five behaviors: flight, foraging, perching, preening, and territorial behavior. We found no difference between the two groups in the percentage of time engaged in each behavior. In addition, we found that transmitters had no apparent effect on use of cavities for roosting by radio-tagged woodpeckers (N = 25).We conclude that backpack transmitters weighing less than 3.6% of body weight had no impact on either their behavior or their ability to use cavities.

  11. SEMI-SUPERVISED RADIO TRANSMITTER CLASSIFICATION BASED ON ELASTIC SPARSITY REGULARIZED SVM

    Institute of Scientific and Technical Information of China (English)

    Hu Guyu; Gong Yong; Chen Yande; Pan Zhisong; Deng Zhantao

    2012-01-01

    Non-collaborative radio transmitter recognition is a significant but challenging issue,sinceit is hard or costly to obtain labeled training data samples.In order to make effective use of the unlabeled samples which can be obtained much easier,a novel semi-supervised classification method named Elastic Sparsity Regularized Support Vector Machine (ESRSVM) is proposed for radio transmitter classification.ESRSVM first constructs an elastic-net graph over data samples to capture the robust and natural discriminating information and then incorporate the information into the manifold learning framework by an elastic sparsity regularization term.Experimental results on 10 GMSK modulated Automatic Identification System radios and 15 FM walkie-talkie radios show that ESRSVM achieves obviously better performance than KNN and SVM,which use only labeled samples for classification,and also outperforms semi-supervised classifier LapSVM based on manifold regularization.

  12. Validation of temperature-sensitive radio transmitters for measurement of body temperature in small animals

    NARCIS (Netherlands)

    Williams, Joseph B.; Tieleman, B. I.; Shobrak, Mohammed

    2009-01-01

    As part of a study on the core body temperature (T(b)) of desert birds, we purposed to use temperature-sensitive implantable radio transmitters. Because of the difficulty in recapturing these birds, we needed to know if these electronic devices held their calibration over the duration of normal batt

  13. Radio transmitter implants in the horns of both the white and the black rhinoceros in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    D.J. Pienaar

    1991-09-01

    Full Text Available The procedure for implanting radio transmitters into the horns of white and black rhinoceroses is described. Mean transmitter life in the white rhinoceros was 13,9 months which is significantly longer than the 9,7 months in black rhinoceros. In the white rhinoceros a significant sex-related difference in transmitter life was found with the transmitters in males lasting a mean of 12,1 months compared to the 15,3 months in females.

  14. Nonlethal gill biopsy does not affect juvenile chinook salmon implanted with radio transmitters

    Science.gov (United States)

    Martinelli-Liedtke, T. L.; Shively, R.S.; Holmberg, G.S.; Sheer, M.B.; Schrock, R.M.

    1999-01-01

    Using gastric and surgical transmitter implantation, we compared radio-tagged juvenile chinook salmon Oncorhynchus tshawytscha (T(O)) with tagged fish also having a gill biopsy (T(B)) to determine biopsy effects on fish implanted with radio transmitters. We found no evidence during the 21-d period to suggest that a gill biopsy reduced survival, growth, or gross condition of the tagged-biopsy group, regardless of transmitter implantation technique. We recorded 100% survival of all treatment groups. Relative growth rates of T(O) and T(B) fish did not differ significantly. Leukocrit and lysozyme levels were not significantly different among groups, suggesting that no signs of infection were present. Our findings suggest that small chinook salmon can tolerate the combination of transmitter implantation and gill biopsy without compromising condition relative to fish receiving only the transmitter. We believe a gill biopsy can be used in field telemetry studies, especially when physiological data are needed in addition to behavioral data.

  15. Wind Tunnel Experiments to Assess the Effect of Back-Mounted Radio Transmitters on Bird Body Drag

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerodynamic drag of bird bodies was measured in a wind tunnel, with and without back-mounted dummy radio transmitters. Flight performance estimates indicate that...

  16. Radio-transmitters do not affect seasonal productivity of female Golden-winged Warblers

    Science.gov (United States)

    Streby, Henry M.; Peterson, Sean M.; Gesmundo, Callie; Johnson, Michael K.; Fish, Alexander C.; Lehman, Justin A.; Andersen, David E.

    2013-01-01

    Investigating the potential effects of handling and marking techniques on study animals is important for correct interpretation of research results and to effect progress in data-collection methods. Few investigators have compared the reproductive output of radio-tagged and non-radio-tagged songbirds, and no one to date has examined the possible effect of radio-tagging adult songbirds on the survival of their fledglings. In 2011 and 2012, we compared several parameters of reproductive output of two groups of female Golden-winged Warblers (Vermivora chrysoptera) breeding in Minnesota, including 45 females with radio-transmitters and 73 females we did not capture, handle, or mark. We found no difference between groups in clutch sizes, hatching success, brood sizes, length of incubation and nestling stages, fledging success, number of fledglings, or survival of fledglings to independence. Thus, radio-tags had no measurable impact on the productivity of female Golden-winged Warblers. Our results build upon previous studies where investigators have reported no effects of radio-tagging on the breeding parameters of songbirds by also demonstrating no effect of radio-tagging through the post-fledging period and, therefore, the entire breeding season.

  17. Subcutaneous anchor attachment increases retention of radio transmitters on Xantus' and marbled murrelets

    Science.gov (United States)

    Newman, Scott H.; Takekawa, John Y.; Whitworth, Darrell L.; Burkett, Esther E.

    1999-01-01

    We modified a subcutaneous anchor attachment and achieved transmitter reten- tion times that exceeded those reported previously for other attachments used on alcids. Traditional suture and epoxy attachment methods were used on Xantus' Murrelets in 1995 and 1996, while the modified attachment was used for Xantus' Murrelets in 1996 and 1997 and Marbled Murrelets in 1997. Modifications included use of an inhalant anesthetic, placing the anchor in a more cranial position on the back, application of marine epoxy, and place- ment of a single subcutaneous non-absorbable suture at the caudal end of the radio to hold the radio in place initially. We located 22 of 56 (39%) Xantus' Murrelets radio-marked using suture and epoxy during aerial surveys in 1995 and 1996. Of birds radio-marked using the subcutaneous anchor attachment, we located 92 of 113 (81%) Xantus' Murrelets marked in 1996 and 1997 and all 28 (100%) Marbled Murrelets marked in 1997 during aerial surveys. The maximum confirmed duration for the subcutaneous anchor transmitter attachment was 51 d for Xantus' Murrelets and 78 d for Marbled Murrelets versus 41 d for the suture and epoxy attachment used on Xantus' Murrelets. Recapture rates of radio-marked Xantus' Mur- relets were similar to recapture rates of unmarked Xantus' Murrelets. Our post-release ob- servations indicated negligible short-term physical effects from the attachment procedure, while telemetry data and examination of recaptured murrelets indicated no evidence of infection or other long-term physical effects. Breeding behavior of some murrelets was not disrupted; however, further evaluation of potential effects of this attachment technique on breeding and behavior is needed.

  18. Energy-Efficient Power Allocation of Cognitive Radio Systems without CSI at the Transmitter

    KAUST Repository

    Sboui, Lokman

    2015-01-07

    Two major issues are facing today’s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produce 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, we aim to determine the optimal energy efficient power allocation of CR when the channel state information at the transmitter CSI-T is not available.

  19. Simulated annealing algorithm for the optimal translation sequence of the jth agent in rough communication

    Institute of Scientific and Technical Information of China (English)

    Wang Hongkai; Guan Yanyong; Xue Peijun

    2008-01-01

    In rough communication, because each agent has a different language and cannot provide precise communication to each other, the concept translated among multi-agents will loss some information and this results in a less or rougher concept. With different translation sequences, the problem of information loss is varied. To get the translation sequence, in which the jth agent taking part in rough communication gets maximum information, a simulated annealing algorithm is used. Analysis and simulation of this algorithm demonstrate its effectiveness.

  20. Prescient Beamforming by Primary Transmitters in Interweave Cognitive Radio Networks with a Single Primary Receiver

    CERN Document Server

    Mukherjee, Amitav

    2011-01-01

    This work investigates a fundamentally novel interweave cognitive radio network where the primary transmitter takes a proactive approach towards improving the accuracy of the spectrum sensing outcomes at the secondary users (SUs). For the single-primary-receiver scenario considered here, the multi-antenna primary user constructs its transmit beamforming vector so as to increase the detection probability at the SUs while meeting a desired Quality-of-Service (QoS) target on its own link, by exploiting either partial or statistical channel state information of the SUs. The objective of such a proactive approach, which we refer to as prescient precoding, is to minimize the probability of interference from SUs at the primary receiver due to imperfect spectrum sensing in fading channels. We also develop information-theoretic bounds on the performance of prescient transmission and study non-linear precoding schemes that approach them. Numerical results are presented to verify the advantages of the proposed prescient...

  1. Inflammatory reaction to fabric collars from percutaneous antennas attached to intracoelomic radio transmitters implanted in harlequin ducks (Histrionicus histrionicus)

    Science.gov (United States)

    Mulcahy, D.M.; Burek, K.A.; Esler, Daniel

    2007-01-01

    In wild birds implanted intracoelomically with radio transmitters, a synthetic fabric collar placed around the base of a percutaneous antenna is believed to function as a barrier to contamination of the coelom. We examined 13 fabric collars recovered from percutaneous antennas of radio transmitters implanted intracoelomically in harlequin ducks (Histrionicus histrionicus) 12 months earlier. Both the transmitters and antenna collars were encapsulated in fibrous connective tissue, with adhesions to internal organs. Histologically, bacteria were evident at the fabric-plastic interface in 8 of 10 collars examined in cross section and along the length of the collar in 3 collars examined longitudinally. Bacteria were confined within the fibrotic sheath surrounding the transmitter and the antenna collar in all birds. No evidence of chronic systemic effects secondary to implantation was present on hematologic or serum biochemical testing. These findings indicate that antenna collars do not prevent the entry of bacteria along the percutaneous antenna but may help stabilize the antenna and minimize coelomic contamination. We conclude that radio transmitters implanted into the coelom of harlequin ducks do not appear to cause significant health problems for at least 1 year after implantation.

  2. Surgical and immediate postrelease mortality of harlequin ducks (Histrionicus histrionicus) implanted with abdominal radio transmitters with percutaneous antennae

    Science.gov (United States)

    Mulcahy, D.M.; Esler, Daniel

    1999-01-01

    Radiotelemetry is an essential tool in the study of free-ranging bird populations, and a variety of transmitter-attachment methods have been developed. A promising new method is abdominal implantation of a transmitter with a percutaneous antenna. Researchers using this technique should be concerned about and aware of mortality during surgery and during the immediate postrelease period (the 14-day period following surgery). Of 307 radio-implant surgeries performed between 1995 and 1997 in harlequin ducks (Histrionicus histrionicus), 7 (2.3%) deaths were documented during surgery or anesthetic recovery. Of 295 birds released with implanted radios, 10 (3.4%) died during the immediate postrelease period. Modifications to anesthetic procedures used in the 204 surgeries performed in 1996 and 1997 reduced mortality to 1.5% during surgery and 1.5% during the immediate postrelease period. Anesthetic modifications included intubation of all birds, placement of birds on an elevated platform that allowed the head to rest at a level lower than the body during surgery, placement of a heated water blanket under the birds during surgery, monitoring of body temperature, and use of electrocardiogram and Doppler ultrasound to monitor heart rates and arrhythmias. Low levels of mortality associated with abdominal implantation of radio transmitters may be unavoidable, but mortality can be minimized with adjustments to anesthetic technique. Copyright 1999 by American Association of Zoo Veterinarians.

  3. Radio Transmitters and Tower Locations, parcel data base attribute; building type, Published in 2006, 1:1200 (1in=100ft) scale, Washoe County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Radio Transmitters and Tower Locations dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Published Reports/Deeds information as...

  4. Radio Transmitters and Tower Locations, Published in Not Provided, 1:4800 (1in=400ft) scale, Warren County Emergency Services.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Radio Transmitters and Tower Locations dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Hardcopy Maps information as of Not...

  5. Radio Transmitters and Tower Locations, County owned/operated emergency communications towers, Published in 2013, 1:600 (1in=50ft) scale, Waupaca County Land Information.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Radio Transmitters and Tower Locations dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Orthoimagery information as of 2013. It...

  6. Assessment of Barotrauma Resulting from Rapid Decompression of Depth Acclimated Juvenile Chinook Salmon Bearing Radio Telemetry Transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard S.; Carlson, Thomas J.; Welch, Abigail E.; Stephenson, John R.; Abernethy, Cary S.; McKinstry, Craig A.; Theriault, Marie-Helene

    2007-09-06

    A multifactor study was conducted by Battelle for the US Army Corps of Engineers to assess the significance of the presence of a radio telemetry transmitter on the effects of rapid decompression from simulated hydro turbine passage on depth acclimated juvenile run-of-the-river Chinook salmon. Study factors were: (1) juvenile chinook salmon age;, subyearling or yearling, (2) radio transmitter present or absent, (3) three transmitter implantation factors: gastric, surgical, and no transmitter, and (4) four acclimation depth factors: 1, 10, 20, and 40 foot submergence equivalent absolute pressure, for a total of 48 unique treatments. Exposed fish were examined for changes in behavior, presence or absence of barotrauma injuries, and immediate or delayed mortality. Logistic models were used to test hypotheses that addressed study objectives. The presence of a radio transmitter was found to significantly increase the risk of barotrauma injury and mortality at exposure to rapid decompression. Gastric implantation was found to present a higher risk than surgical implantation. Fish were exposed within 48 hours of transmitter implantation so surgical incisions were not completely healed. The difference in results obtained for gastric and surgical implantation methods may be the result of study design and the results may have been different if tested fish had completely healed surgical wounds. However, the test did simulate the typical surgical-release time frame for in-river telemetry studies of fish survival so the results are probably representative for fish passing through a turbine shortly following release into the river. The finding of a significant difference in response to rapid decompression between fish bearing radio transmitters and those not implies a bias may exist in estimates of turbine passage survival obtained using radio telemetry. However, the rapid decompression (simulated turbine passage) conditions used for the study represented near worst case exposure

  7. Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography.

    Science.gov (United States)

    Wallage, A L; Gaughan, J B; Lisle, A T; Beard, L; Collins, C W; Johnston, S D

    2017-03-23

    Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT (r > 0.94, P  0.80, P < 0.001). Surgery produced temporary minor inflammation and scrotal hematoma in two animals post-surgery. Whilst scar tissue was observed at all surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.

  8. Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography

    Science.gov (United States)

    Wallage, A. L.; Gaughan, J. B.; Lisle, A. T.; Beard, L.; Collins, C. W.; Johnston, S. D.

    2017-07-01

    Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT ( r > 0.94, P 0.80, P < 0.001). Surgery produced temporary minor inflammation and scrotal hematoma in two animals post-surgery. Whilst scar tissue was observed at all surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.

  9. Exposure to radio-frequency electromagnetic fields from broadcast transmitters and risk of childhood cancer : A census-based cohort study

    NARCIS (Netherlands)

    Hauri, Dimitri D.; Spycher, Ben; Huss, Anke; Zimmermann, Frank; Grotzer, Michael; Von Der Weid, Nicolas; Spoerri, Adrian; Kuehni, Claudia E.; Röösli, Martin

    2014-01-01

    We investigated the association between exposure to radio-frequency electromagnetic fields (RF-EMFs) from broadcast transmitters and childhood cancer. First, we conducted a time-to-event analysis including children under age 16 years living in Switzerland on December 5, 2000. Follow-up lasted until

  10. Game-Theoretic Beamforming and Power Allocation in MIMO Cognitive Radio Systems with Transmitter Antenna Correlation

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2015-01-01

    Full Text Available Multi-input multioutput (MIMO technique provides a promising solution to enhance the performance of wireless communication systems. In this paper, we consider antenna correlation at the transmitter in practical cognitive MIMO systems. What is more, a game-theoretic framework is conducted to analyze the optimum beamforming and power allocation such that each user maximizes its own rate selfishly under the transmitting power constraint and the primary user (PU interference constraint. The design of the cognitive MIMO system is formulated as a noncooperative game, where the secondary users (SUs compete with each other over the resources made available by the PUs. Interestingly, as the correlation parameter grows, the utility degrades. Nash equilibrium is considered as the solution of this game. Simulation results show that the proposed algorithm can converge quickly and clearly outperforms the strategy without game.

  11. Introduce the Development of the Technology of the FM Radio Transmitter%调频广播发射机技术的发展趋向

    Institute of Scientific and Technical Information of China (English)

    武海波; 王毅; 吴先华

    2014-01-01

    通过对美国哈里斯公司近年先后推出的Z10CD和Flexiva FAX 10K两型大功率调频广播发射机进行比较、分析,对未来调频广播发射机特别是大功率发射机的发展趋势进行思考,提出了调频大功率广播发射机向高可靠性、高效率、高质量、高集成、高智能等方向发展的观点。%By comparing and analyzing Z10CD FM broadcast transmitter to FAX 10k FM broadcast transmitter which has been introduced by Harris in recent years,and thinking about the future trends of FM radio transmit-ter,especially for high-power transmitter,that the development of the FM radio transmitter is high reliability, high efficiency,high quality,high integration and intelligence.

  12. Radio Transmitters and Tower Locations, Layer includes all towers identified visually and include cellular and other communication towers., Published in 2008, 1:1200 (1in=100ft) scale, Noble County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Radio Transmitters and Tower Locations dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Field Observation information as of...

  13. Exposure to radio-frequency electromagnetic fields from broadcast transmitters and risk of childhood cancer: a census-based cohort study.

    Science.gov (United States)

    Hauri, Dimitri D; Spycher, Ben; Huss, Anke; Zimmermann, Frank; Grotzer, Michael; von der Weid, Nicolas; Spoerri, Adrian; Kuehni, Claudia E; Röösli, Martin

    2014-04-01

    We investigated the association between exposure to radio-frequency electromagnetic fields (RF-EMFs) from broadcast transmitters and childhood cancer. First, we conducted a time-to-event analysis including children under age 16 years living in Switzerland on December 5, 2000. Follow-up lasted until December 31, 2008. Second, all children living in Switzerland for some time between 1985 and 2008 were included in an incidence density cohort. RF-EMF exposure from broadcast transmitters was modeled. Based on 997 cancer cases, adjusted hazard ratios in the time-to-event analysis for the highest exposure category (>0.2 V/m) as compared with the reference category (exposure from broadcasting and childhood leukemia. Results for CNS tumors were less consistent, but the most comprehensive analysis did not suggest an association.

  14. 47 CFR 90.471 - Points of operation in internal transmitter control systems.

    Science.gov (United States)

    2010-10-01

    ...) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Transmitter Control Internal Transmitter Control Systems § 90.471 Points of operation in internal transmitter control systems. The... licensee for internal communications and transmitter control purposes. Operating positions in...

  15. Humeral remodeling and soft tissue injury of the wings caused by backpack harnesses for radio transmitters in New Zealand Takahē (Porphyrio hochstetteri).

    Science.gov (United States)

    Michael, Sarah; Gartrell, Brett; Hunter, Stuart

    2013-07-01

    Backpack harnesses are commonly used to attach radio and satellite transmitters to a wide range of bird species for research and conservation management. They are an integral part of the conservation management of the New Zealand Takahē (Porphyrio hochstetteri), an endangered flightless rail. Radio transmitters mounted on backpack harnesses enable the birds to be tracked in their remaining native range of remote, mountainous Fiordland, New Zealand. We evaluated 26 Takahē retrospectively at necropsy by gross examination, radiography, and computed tomography to assess damage from the backpack harness. Ten birds that had never worn a harness had no evidence of wing injury. Of the 16 birds that had worn a harness, 10 (63%) had superficial soft tissue injury to skin or patagium or more severe injury, such as remodeling of the distal humerus at the harness cord-wing interface, or pathologic fractures. Such injuries are hypothesized to be associated with discomfort, increased risk of infection or fracture, and therefore reduced fitness. These findings have implications for all avian species deployed with backpack harnesses.

  16. Radio Transmitters and Tower Locations, CommunicationTowers-The data contains the locations and names of radio and television transmission towers found in Utah., Published in 2001, 1:100000 (1in=8333ft) scale, State of Utah Automated Geographic Reference Center.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Radio Transmitters and Tower Locations dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Other information as of 2001. It is...

  17. Pedestrian Tracking Solution Combining an Impulse Radio Handset Transmitter with an Ankle-Mounted Inertial Measurement Unit

    Directory of Open Access Journals (Sweden)

    Joe Youssef

    2012-01-01

    Full Text Available We address the indoor tracking problem by combining an Impulse Radio-Ultra-Wideband handset with an ankle-mounted Inertial Measurement Unit embedding an accelerometer and a gyroscope. The latter unit makes possible the detection of the stance phases to overcome velocity drifts. Regarding radiolocation, a time-of-arrival estimator adapted to energy-based receivers is applied to mitigate the effects of dense multipath profiles. A novel quality factor associated with this estimator is also provided as a function of the received signal-to-noise ratio, enabling us to identify outliers corresponding to obstructed radio links and to scale the covariance matrix of radiolocation measurements. Finally, both radio and inertial subsystems are loosely-coupled into one single navigation solution relying on a specific extended Kalman filter. In the proposed fusion strategy, processed inertial data control the filter state prediction whereas Combined Time Differences Of Arrival are formed as input observations. These combinations offer low computational complexity as well as a unique filter structure over time, even after removing outliers. Experimental results obtained in a representatively harsh indoor environment emphasize the complementarity of the two technologies and the relevance of the chosen fusion method while operating with low-cost, noncollocated, asynchronous, and heterogeneous sensors.

  18. 47 CFR 80.215 - Transmitter power.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transmitter power. 80.215 Section 80.215... MARITIME SERVICES General Technical Standards § 80.215 Transmitter power. (a) Transmitter power shown on the radio station authorization is the maximum power the licensee is authorized to use. Power...

  19. Childhood leukemia in relation to radiofrequency electromagnetic fields emitted from television and radio broadcast transmitters. Results of a case-control study; Leukaemien im Kindesalter und elektromagnetische Felder in der Umgebung von Rundfunkstationen. Ergebnisse einer Fall-Kontroll-Studie

    Energy Technology Data Exchange (ETDEWEB)

    Schmiedel, Sven [Danish Cancer Society, Copenhagen (Denmark). Inst. of Cancer Epidemiology; Universitaetsmedizin Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Merzenich, Hiltrud; Bennack, Sabrina; Blettner, Maria [Universitaetsmedizin Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Brueggemeyer, Hauke [Niedersaechsischer Landesbetrieb fuer Wasserwirtschaft, Kuesten- und Naturschutz, Hildesheim (Germany). AB35 - Strahlenschutz in Niedersachsen; Philipp, Johannes [Suedwestrundfunk, Stuttgart (Germany). Abt. Frequenz- und Versorgungsplanung; Schuetz, Joachim [Danish Cancer Society, Copenhagen (Denmark). Inst. of Cancer Epidemiology

    2009-07-01

    The causes of childhood leukemia are poorly understood. Radio frequency electromagnetic fields (RF-EMF) emitted from broadcast stations are possible risk factors. A case-control study was conducted in West Germany on RF-EMF and childhood leukemia. The study region consisted of municipalities near 24 radio and television transmitters. Cases (aged 0-14 years, diagnosis 1984-2003) were registered at the German childhood cancer registry. Three age-, gender- and transmitter areamatched controls per case were drawn randomly from population registries. The analysis included 1,959 cases and 5,848 controls. The RF-EMF exposure was calculated with a field strength prediction program. In the statistical analysis conditional logistic regression was used. Considering total RF-EMF, the odds ratio for leukemia was 0.86 (95% confidence interval 0.67-1.11) comparing upper ({>=}95%) and lower (<90%) quantile for the RF-EMF distribution. No association between RF-EMF exposure and leukemia was observed for the time periods before and after the introduction of mobile telecommunication. There was no increased risk among children living in the 2 km vicinity of the transmitters. The study provides no evidence for an association between RF-EMF and childhood leukemia. (orig.)

  20. 短波广播发射机栅流传感器的工作原理与参数调整%Principle and Parameter Adjustment Shortwave Radio Transmitter Gate Current Sensor

    Institute of Scientific and Technical Information of China (English)

    李爱民

    2015-01-01

    本文简要介绍了短波广播发射机高末电子管栅极电路中栅流传感器工作原理,针对典型的100KwPSM短波发射机高末栅极电路进行了分析,在讨论广播发射机高末栅流信号大小检测方法和栅流传感器在发射机控制系统中所起的重要作用的同时,也对栅流传感器在实际工作中出现故障时的应急处理进行了论述.%This paper describes the high end of the tube shortwave radio transmitter gate gate circuit flow sensor works, a typical high-end gate 100KwPSM shortwave transmitter circuits are analyzed, in high-end broadcast transmitter signal grid current size detection methods discussed and while the gate flow sensor in the transmitter control system plays an important role, for emergency gate flow sensor in practice, when the fault occurred are discussed.

  1. Operation and Maintenance of Antenna Switch Based on the Radio Transmitter%基于广播发射机天线交换开关运行维护探析

    Institute of Scientific and Technical Information of China (English)

    王文杰

    2015-01-01

    The high power short wave radio transmitting usually have a number of transmitter and radio coverage task for several directions respectively. Due to the time of each frequency band, broadcast transmitter, the transmitting antenna Angle and service in a different direction, to make full use of the transmitter and the transmitting antenna resources, ensuring uninterrupted broadcast; In order to make the transmitter output automatically by the transmission feeder, flexible switching to a different transmitting antenna, the antenna switching control switch is the first choice of implementing these.%大功率短波广播发射台一般都有多部发射机,分别担负好几个方向的广播覆盖任务。由于每部发射机工作频段、播音时间、发射天线角度和服务方向不同,为了充分利用发射机和发射天线资源,保障不间断的播出,为了使发射机输出通过传输馈线自动、灵活切换到不同的发射天线上,天线交换控制开关是实现这些功能的首选设备。本文简要介绍了天线交换控制开关工作原理,并以 DF-100A 型短波发射机TKP-Ⅲ天线交换开关控制柜和 TK5天线交换开关为例,针对实际工作中运行维护所出现的典型故障以及故障处理进行了分析论述。

  2. 47 CFR 15.212 - Modular transmitters.

    Science.gov (United States)

    2010-10-01

    ... modular transmitter must have their own shielding. The physical crystal and tuning capacitors may be... shielded. The physical crystal and tuning capacitors may be located external to the shielded radio...

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

    Science.gov (United States)

    Cown, Steven H.; Derr, Kurt Warren

    2010-03-16

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

  4. Childhood leukaemia in relation to radiofrequency electromagnetic fields emitted from television and radio broadcast transmitters: epidemiological aspects of a case-control study in Germany; Leukaemie bei Kindern in der Umgebung von Sendestationen des Rundfunks. Anforderungen an das Studiendesign

    Energy Technology Data Exchange (ETDEWEB)

    Merzenich, H.; Bennack, S.; Blettner, M. [Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Schmiedel, S.; Schuez, J. [Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Danish Cancer Society, Copenhagen (Denmark). Inst. of Cancer Epidemiology; Brueggemeyer, H. [Niedersaechsischer Landesbetrieb fuer Wasserwirtschaft, Kuesten- und Naturschutz, AB35 - Strahlenschutz in Niedersachsen, Hannover (Germany); Philipp, J. [Suedwestrundfunk, Stuttgart (Germany). Abt. Frequenz- und Versorgungsplanung; Spix, C. [Mainz Univ. (Germany). Deutsches Kinderkrebsregister

    2007-07-01

    Leukaemia is the most common type of cancer in children accounting for about a third of all cancers in children under the age of 15 years. Environmental factors such as non-ionising radiation exposure might play a role in the aetiology of childhood leukaemia. However, data to support such hypotheses are inconsistent. A case control study has been set up in West Germany (University of Mainz) in order to determine whether there is an increased risk of childhood leukaemia in populations exposed to radiofrequency electromagnetic fields from TV and/or Radio towers. Cases are children aged 0 to 14 years with a primary leukaemia diagnosed between 1984 and 2003 who lived in the vicinity of these TV- and/ or Radio towers. Cases have been identified through the German Childhood Cancer Registry. Three controls per case have been individually matched by age at diagnosis, sex, time of diagnosis and study area. The study focuses on an individual retrospective exposure assessment using data from transmitter network operators. The study has started in March 2005 with a pilot investigation in order to specify the study design and the methods for exposure assessment. A total of 2009 eligible cases have been identified. The study will be finished end of 2007. (orig.)

  5. Terrestrial VLF transmitter injection into the magnetosphere

    OpenAIRE

    2012-01-01

    Terrestrial VLF transmitter injection into the magnetosphere M. B. Cohen1 and U. S. Inan1,2 Received 1 June 2012; revised 15 June 2012; accepted 18 June 2012; published 9 August 2012. [1] Very Low Frequency (VLF, 3–30 kHz) radio waves emitted from ground sources (transmitters and lightning) strongly impact the radiation belts, driving electron precipitation via whistler-electron gyroresonance, and contributing to the formation of the slot region. However, calculations of the...

  6. System for Isolation Testing of RF Transmitters and Receivers

    Science.gov (United States)

    2012-08-03

    one such software defined radio is the open source GNU radio platform utilizing the Universal Software Radio Peripheral. [0019] The advantages of...to a system that can perform isolation testing of a radio frequency (RF) transmitter or an RF receiver. (2) Description of the Prior Art [0004...Currently, the testing and diagnosing of a faulty radio frequency (RF) transmission and receiving systems requires that the system be taken out of the

  7. 47 CFR 73.685 - Transmitter location and antenna system.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Transmitter location and antenna system. 73.685... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.685 Transmitter location and antenna system... and antenna height above average terrain employed, the following minimum field strength in dB...

  8. 47 CFR 95.629 - LPRS transmitter frequencies.

    Science.gov (United States)

    2010-10-01

    ....629 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Technical Regulations Technical Standards § 95.629 LPRS transmitter frequencies. (a....8075 223 216.8125 224 216.8175 225 216.8225 226 216.8275 227 216.8325 228 216.8375 229 216.8425 230...

  9. Spectrum management and radio resource management considering cognitive radio systems

    NARCIS (Netherlands)

    Haartsen, Jaap C.; Wieweg, Lasse; Huschke, Jörg

    2005-01-01

    International fora and some national administrations define a cognitive radio (CR) as a pioneering radio communication system that would be capable of altering and adapting its transmitter and receiver parameters based on communication and the exchange of information with related detectable radio co

  10. A taping method for external transmitter attachment on aquatic snakes

    Science.gov (United States)

    Wylie, G.D.; Smith, J.J.; Amarello, M.; Casazza, M.L.

    2011-01-01

    Radio telemetry is extremely useful for studying habitat use and movements of free ranging snakes. Surgically implanting radio transmitters into the body cavity of snakes is standard practice in most studies (e.g., Reinert and Cundall 1982; Weatherhead and Blouin-Demers 2004), but this implanting method has its drawbacks. Surgery itself is risky for individual snakes because of the potential for infection or incomplete healing of the incision site. Also, transmitters that are small enough to be carried by small or slender snakes have a relatively short battery life and need to be removed or replaced often, thus requiring frequent surgeries. In rare or endangered snake species, the risk of using invasive implantation surgery may not be merited. External attachment methods are relatively non-invasive and allow removal and replacement of radio transmitters on smaller snakes. The Giant Gartersnake (Thamnophis gigas) is a semi-aquatic snake endemic to wetlands of the Central Valley of California, USA, and is federally and state listed as threatened (U.S. Fish and Wildlife Service 1999). Telemetry studies of the habitat use and movements of this species typically used surgically implanted radio transmitters, but this method is limited to larger snakes, primarily females, because of size requirements for surgery (> 250 g). To overcome difficulties and biases associated with radio telemetry of T. gigas, we developed and evaluated several alternative techniques to attach external radio transmitters using tape.

  11. Ham radio for dummies

    CERN Document Server

    Silver, H Ward

    2013-01-01

    An ideal first step for learning about ham radio Beyond operating wirelessly, today's ham radio operators can transmit data and pictures; use the Internet, laser, and microwave transmitters; and travel to places high and low to make contact. This hands-on beginner guide reflects the operational and technical changes to amateur radio over the past decade and provides you with updated licensing requirements and information, changes in digital communication (such as the Internet, social media, and GPS), and how to use e-mail via radio. Addresses the critical use of ham radio for replacing downe

  12. Transionospheric Propagation of VLF Transmitter Signals

    Science.gov (United States)

    Cohen, M.; Inan, U. S.; Lehtinen, N. G.

    2012-12-01

    Ground based Very Low Frequency (VLF, 3-30 kHz) radio transmitters may play a significant role in precipitation of inner belt (L<2.5) energetic Van Allen electrons. Initial analyses of the total contribution of VLF transmitters utilized models of transionospheric propagation, but some recent studies have suggested that those models may overestimate (by 20-100 dB) the VLF energy reaching the magnetosphere. One possible cause of this discrepancy was suggested to be conversion of wave energy into electrostatic modes in the D, E, and F regions, from ionospheric density irregularities, either natural or generated by the transmitter heating itself. The DEMETER satellite built a six year history of continuous and global survey mode data which, when combined, yields detailed pictures of the radiation pattern from many transmitters into space at 680 km, with 25 km resolution, and clear features like the interference pattern on the ground mapped upwards. With both E and B survey mode data, we can also directly approximate the total power injected into the magnetosphere from each transmitter, separately for day and night, as well as the power arriving at the conjugate region. We find no detectable variation of signal intensity with geomagnetic conditions. We find evidence of transmitter heating affecting the transionospheric propagation of other transmitters. We find that the power reaching the conjugate region is a large fraction of the power injected above the transmitter. We then employ a full wave model to simulate VLF transmitter transionospheric propagation, calculating the electromagnetic fields and power flux injected into the magnetosphere. Although the model does not include ionospheric irregularities, the radiation pattern largely matches the observed one, and the total power calculated is within 6 dB of observations for every transmitter, both day and night, and across a range of low to middle latitudes and transmitter powers. We thus conclude that the effect of

  13. Testing tail-mounted transmitters with Myocastor coypus (nutria)

    Science.gov (United States)

    Merino, S.; Carter, J.; Thibodeaux, G.

    2007-01-01

    We developed a tail-mounted radio-transmitter for Myocastor coypus (nutria) that offers a practical and efficient alternative to collar or implant methods. The mean retention time was 96 d (range 57-147 d, n = 7), making this a practical method for short-term studies. The tail-mounts were less injurious to animals than collars and easier for field researchers to implement than either collars or surgically implanted transmitters.

  14. Breaking the Transmitter-Receiver Isolation Barrier in Mobile Handsets with Spatial Duplexing

    DEFF Research Database (Denmark)

    Alrabadi, Osama; Tatomirescu, Alexandru; Knudsen, Mikael;

    2013-01-01

    In full-duplex radio communication systems like eUTRAN, CDMA-2000, the radio transmitter (Tx) is active at the same time as the radio receiver (Rx). The Tx and the Rx will be using separate dedicated frequency bands and the Tx-Rx isolation is ensured by duplex filters. However, agile duplexers req...

  15. 47 CFR 95.419 - (CB Rule 19) May I operate my CB station transmitter by remote control?

    Science.gov (United States)

    2010-10-01

    ... transmitter by remote control? 95.419 Section 95.419 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Operate A Cb Station § 95.419 (CB Rule 19) May I operate my CB station transmitter by remote control? (a) You may not operate a CB station transmitter by radio remote control. (b) You may operate a CB...

  16. The Use of a Solid State Analog Television Transmitter as a Superconducting Electron Gun Power Amplifier

    Energy Technology Data Exchange (ETDEWEB)

    J.G. Kulpin, K.J. Kleman, R.A. Legg

    2012-07-01

    A solid state analog television transmitter designed for 200 MHz operation is being commissioned as a radio frequency power amplifier on the Wisconsin superconducting electron gun cavity. The amplifier consists of three separate radio frequency power combiner cabinets and one monitor and control cabinet. The transmitter employs rugged field effect transistors built into one kilowatt drawers that are individually hot swappable at maximum continuous power output. The total combined power of the transmitter system is 33 kW at 200 MHz, output through a standard coaxial transmission line. A low level radio frequency system is employed to digitally synthesize the 200 MHz signal and precisely control amplitude and phase.

  17. A High Efficiency Fully Integrated OOK Transmitter for WBAN

    Institute of Scientific and Technical Information of China (English)

    Mousa Yousefi; Ziaddin Daie Koozehkanani; Jafar Sobhi; Hamid Jangi

    2014-01-01

    ⎯A 2.4 GHz high efficiency radio frequency (RF) transmitter for wireless body area network (WBAN) in medical applications is presented in this paper. The transmitter architecture with high energy efficiency is proposed to achieve a high data rate with low power consumption. In conventional transmitters, the oscillator and power amplifier are turned off when the transmitter sends 0. The required time for turning oscillator ON/OFF is longer than the other blocks of the transmitter. In the proposed transmitter, the low power oscillator is on all the time while the power amplifier and modulator are turned off when“0”data is sent. The transmitter consumes 3.2 mW at 0.5 dBm output by 285 Mbps data rate and the energy consumption per transmitted bit with 0.5 dBm output power is 10 pJ/(bit⋅mW). The proposed transmitter was designed in 0.18 µm CMOS technology.

  18. 47 CFR 22.165 - Additional transmitters for existing systems.

    Science.gov (United States)

    2010-10-01

    ...-ground Radiotelephone Service. Ground stations may be added to Commercial Aviation air-ground systems at... the same channel. This section does not apply to Basic Exchange Telecommunications Radio Systems. (h... 47 Telecommunication 2 2010-10-01 2010-10-01 false Additional transmitters for existing...

  19. Design of a fiber-optic transmitter for microwave analog transmission with high phase stability

    Science.gov (United States)

    Logan, R. T., Jr.; Lutes, G. F.; Primas, L. E.; Maleki, L.

    1990-01-01

    The principal considerations in the design of fiber-optic transmitters for highly phase-stable radio frequency and microwave analog transmission are discussed. Criteria for a fiber-optic transmitter design with improved amplitude and phase-noise performance are developed through consideration of factors affecting the phase noise, including low-frequency laser-bias supply noise, the magnitude and proximity of external reflections into the laser, and temperature excursions of the laser-transmitter package.

  20. A 100–800 MHz 8-Path polyphase transmitter with mixer duty-cycle control achieving

    NARCIS (Netherlands)

    Subhan, Saqib; Klumperink, Eric; Ghaffari, Amir; Wienk, Gerard; Nauta, Bram

    2014-01-01

    Radio transceivers capable of dynamic spectrum access require frequency agile transmitters with a clean output spectrum. High-Q filters are difficult to implement on chip and have limited tuning range. Transmitters with high linearity and broadband harmonic rejection can be more flexible and require

  1. 47 CFR 80.927 - Antenna radio frequency indicator.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna radio frequency indicator. 80.927... Boats § 80.927 Antenna radio frequency indicator. The transmitter must be equipped with a device which provides visual indication whenever the transmitter is supplying power to the antenna. ...

  2. 47 CFR 80.1019 - Antenna radio frequency indicator.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Antenna radio frequency indicator. 80.1019... Act § 80.1019 Antenna radio frequency indicator. Each nonportable bridge-to-bridge transmitter must be... indication when the transmitter is supplying power to the antenna transmission line or, in lieu thereof, a...

  3. Study of relationship between structure and transmittance of diamond-like carbon (DLC) films

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this paper, the transparent hard diamond-like carbon (DLC) films were deposited on glass substrate by magnetic confined radio-frequency plasma chemical vapor deposition. The structure of films was studied by Raman spectra and X-ray photoelectron spectra (XPS), the transmittance of films by Spectrophotometer. The mechanism of the influence of films structure on transmittance of the films was discussed. The results show that the thickness of films was lower than 100nm, and the transmittance was over 90% in 380-780 nm region. Discussion in theory on the influence of film structure on transmittance was correspondence to experiment results.

  4. 47 CFR 95.217 - (R/C Rule 17) May I operate my R/C station transmitter by remote control?

    Science.gov (United States)

    2010-10-01

    ... transmitter by remote control? 95.217 Section 95.217 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... control? (a) You may not operate an R/C transmitter by radio remote control. (See R/C Rule 12, § 95.212.) (b) You may operate an R/C transmitter by wireline remote control if you obtain specific approval in...

  5. Radio Frequency Power Load and Associated Method

    Science.gov (United States)

    Srinivasan, V. Karthik (Inventor); Freestone, Todd M. (Inventor); Sims, William Herbert, III (Inventor)

    2014-01-01

    A radio frequency power load and associated method. A radio frequency power load apparatus may include a container with an ionized fluid therein. The apparatus may include one conductor immersed in a fluid and another conductor electrically connected to the container. A radio frequency transmission system may include a radio frequency transmitter, a radio frequency amplifier connected to the transmitter and a radio frequency power load apparatus connected to the amplifier. The apparatus may include a fluid having an ion source therein, one conductor immersed in a fluid, and another conductor electrically connected to the container. A method of dissipating power generated by a radio frequency transmission system may include constructing a waveguide with ionized fluid in a container and connecting the waveguide to an amplifier of the transmission system.

  6. 47 CFR 74.461 - Transmitter power.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Transmitter power. 74.461 Section 74.461....461 Transmitter power. (a) Transmitter power is the power at the transmitter output terminals and.... For the purpose of this Subpart, the transmitter power is the carrier power. (b) The...

  7. A robust beamformer design for underlay cognitive radio networks using worst case optimization

    National Research Council Canada - National Science Library

    Wijewardhana, Uditha Lakmal; Codreanu, Marian; Latva-aho, Matti; Ephremides, Anthony

    2014-01-01

    We propose a robust beamforming design for underlay cognitive radio networks where multiple secondary transmitters communicate with corresponding secondary receivers and coexist with a primary network...

  8. A Clock Fingerprints-Based Approach for Wireless Transmitter Identification

    Science.gov (United States)

    Zhao, Caidan; Xie, Liang; Huang, Lianfen; Yao, Yan

    Cognitive radio (CR) was proposed as one of the promising solutions for low spectrum utilization. However, security problems such as the primary user emulation (PUE) attack severely limit its applications. In this paper, we propose a clock fingerprints-based authentication approach to prevent PUE attacks in CR networks with the help of curve fitting and classifier. An experimental setup was constructed using the WLAN cards and software radio devices, and the corresponding results show that satisfied identification can be achieved for wireless transmitters.

  9. Transmitter microdischarges in communications and broadcast Satellites

    Science.gov (United States)

    Briskman, Robert D.; Kaliski, Michael A. R.

    2016-09-01

    Most commercial communications and broadcast satellites operating at microwave radio frequencies use traveling wave tube amplifiers (TWTAs) as high power transmitters. Since TWTAs work at high voltages, it is not uncommon to experience micro-discharges, especially early in life. This observation led to the introduction of an autonomous restart function in the companion high voltage power supply (the electronic power conditioner or EPC) of the TWTA as a safety feature. A microdischarge with enough energy above a threshold would lead to a momentary removal of high voltages, followed by an automatic restart, which is usually sufficient to allow the microdischarge event to clear with minimal loss of RF transmission. In most cases the energy involved in the microdischarge is low enough that the removal of high voltages is not required and the event may go undetected. However, an unusual signature was first noted in early 1997 on a Ku-band satellite transmitter, where the characteristics of the microdischarge event were such that the control anode voltage dropped below nominal and typically recovered over a 20 min period. Such microdischarge events became known as the "20 min Effect" which has since been observed over subsequent years on other Ku-band TWTAs, as well as on Ka-band and S-band satellite TWTA transmitters in numerous satellites. This paper summarizes the in-orbit data on such microdischarges as well as the believed cause. In addition, the paper includes results from three S-band TWTAs which have operated on life test for many years. Due to ease of their monitoring instrumentation as contrast to monitoring microdischarges on orbiting operational satellites via telemetry, new data have been accumulated on this effect. The data substantiate the previous findings that microdischarges do not significantly affect satellite operation or their transmissions nor diminish the TWTAs performance, including long lifetime.

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

    Science.gov (United States)

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

    2013-05-01

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

  11. An optical analog signal transmitter

    Energy Technology Data Exchange (ETDEWEB)

    Fudzita, K.; Itida, T.; Tanaka, Kh.

    1984-01-11

    An optical laser analog signal transmitter employing an amplitude modulated subcarrier is patented; this transmitter performs stable and high quality transmission of information signals over great distances. A feature of the proposed transmitter is a special transmitter operational mode in which the light emission reflected off the connection point to the fiber optic conduit is sent back to the laser diode in a transient period. As a result, the critical mode of the generated emission is not influenced by the reflected signal. The transmitter consists of a laser diode with biasing near the cutoff point, an amplitude modulator with a subcarrier frequency oscillator, a section of flexible fiber-optic cable of length L, which connects the laser diode to the primary optical fiber conduit, and the connector itself. The subcarrier frequency may vary over wide ranges to establish the necessary correlation between the length of the light conduit section L and the return propagation time of the reflected light signal from the connection point to the laser diode. The difference between the lasing time of the light signal and the return time to the laser diode of the signal reflected off the connector is determined by the relation tau equals 2nL/c - mtauc, where L is the length of the connecting section; n is the refractivity of the optical fiber; c is the velocity of light; tauc is the period of the high frequency subcarrier signal; and m is an integer.

  12. Circuit Bodging: FM bug transmitter

    NARCIS (Netherlands)

    Allen, B.

    2010-01-01

    Many people have their interest in electronics start with radio. As much as radio is taken for granted by most people, the idea of sending information through the through the air at the speed of light remains enticing to anyone who thinks about it for longer than a few minutes. As such, we submit to

  13. 47 CFR 95.628 - MedRadio transmitters.

    Science.gov (United States)

    2010-10-01

    ... interrupted by interference. The following criteria must be met: (i) Before transmitting on the alternate... implanted permanent medical device that is intended to replace the temporary body-worn device; (ii) RF...

  14. Effects of surgically implanted dummy transmitters on the South American catfish Jundiá (Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    Schulz U. H.

    2003-01-01

    Full Text Available High water temperatures and low water quality may negatively influence wound healing, growth and transmitter retention in radio-tagged fish of tropical and subtropical water bodies which in turn may hamper radio tracking studies. For a period of 90 days, we compared growth of an experimental group of ten Rhamdia quelen, which were submitted to intraperitoneal dummy transmitter implantation, with that of a control group. Additionally, wound healing and transmitter expulsion were observed in the experimental group. Water temperature varied between 24degreesC and 30degreesC during the study. Experimental group and control fish decreased in body weight during the investigation period, but the differences between the mean individual weight loss in both groups were not significant (Student t-test, p = 0.64. Wound healing in experiment group fish was advanced after 14 days, while after 70 days eight out of ten incision wounds were closed and cicatrized. One fish had its dummy transmitter expulsed through the ventral body wall. After 90 days two more fish had the dummies expulsed, one through the ventral body wall and the other through the antenna exit. One experimental group fish died with visible signs of infection. The results encourage the use of surgically implanted radio transmitters for long-term tagging studies at high water temperatures.

  15. Effects of surgically implanted dummy transmitters on the South American catfish Jundiá (Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    U. H. Schulz

    Full Text Available High water temperatures and low water quality may negatively influence wound healing, growth and transmitter retention in radio-tagged fish of tropical and subtropical water bodies which in turn may hamper radio tracking studies. For a period of 90 days, we compared growth of an experimental group of ten Rhamdia quelen, which were submitted to intraperitoneal dummy transmitter implantation, with that of a control group. Additionally, wound healing and transmitter expulsion were observed in the experimental group. Water temperature varied between 24°C and 30°C during the study. Experimental group and control fish decreased in body weight during the investigation period, but the differences between the mean individual weight loss in both groups were not significant (Student t-test, p = 0.64. Wound healing in experiment group fish was advanced after 14 days, while after 70 days eight out of ten incision wounds were closed and cicatrized. One fish had its dummy transmitter expulsed through the ventral body wall. After 90 days two more fish had the dummies expulsed, one through the ventral body wall and the other through the antenna exit. One experimental group fish died with visible signs of infection. The results encourage the use of surgically implanted radio transmitters for long-term tagging studies at high water temperatures.

  16. [Pain and its main transmitters].

    Science.gov (United States)

    Costentin, J

    2000-03-01

    The pain message originates peripherally from a great variety of substances either released from preformed stores or extemporaneously synthetized. They stimulate or sensitize nociceptors which are associated with the peripheral endings of sensitive protoneurones. Their central endings release many types of transmitters in the dorsal horn of medulla (substance P, NO, CGRP.). At this level their release, triggered by the firing rate, is modulated by the stimulation of various presynaptic receptors operated by transmitters produced by either interneurones (enkephalins) or medullar descending neurons (dopamine, norepinephrine, serotonine). These modulations correspond to the so-called gate control. The sensitive consecutive neurones which climb towards various brain areas are submitted to contradictory influences. Several of them enhance the pain perception (nociceptin, cholecystokinin, neuropeptide FF.) whereas several other reduce it (endorphines, neurotensin, neuromedin N, anandamide.).

  17. 47 CFR 101.513 - Transmitter power.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transmitter power. 101.513 Section 101.513... SERVICES 24 GHz Service and Digital Electronic Message Service § 101.513 Transmitter power. The transmitter power will be governed by § 101.113. Further, each application must contain an analysis...

  18. 47 CFR 101.807 - Transmitter power.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transmitter power. 101.807 Section 101.807... SERVICES Local Television Transmission Service § 101.807 Transmitter power. Stations in this service will not be authorized to use transmitters having a rated power output in excess of the limits set forth...

  19. 47 CFR 90.549 - Transmitter certification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transmitter certification. 90.549 Section 90...-775 and 793-805 MHz Bands § 90.549 Transmitter certification. Transmitters operated in the 763-775 MHz... its certification procedure as required by § 90.203....

  20. 47 CFR 80.169 - Operators required to adjust transmitters or radar.

    Science.gov (United States)

    2010-10-01

    ... radar. 80.169 Section 80.169 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Requirements § 80.169 Operators required to adjust transmitters or radar. (a) All adjustments of radio... transmitting Morse code. (c) Only persons holding an operator certificate containing a ship radar endorsement...

  1. Flexible, reconfigurable, power efficient transmitter and method

    Science.gov (United States)

    Bishop, James W. (Inventor); Zaki, Nazrul H. Mohd (Inventor); Newman, David Childress (Inventor); Bundick, Steven N. (Inventor)

    2011-01-01

    A flexible, reconfigurable, power efficient transmitter device and method is provided. In one embodiment, the method includes receiving outbound data and determining a mode of operation. When operating in a first mode the method may include modulation mapping the outbound data according a modulation scheme to provide first modulation mapped digital data, converting the first modulation mapped digital data to an analog signal that comprises an intermediate frequency (IF) analog signal, upconverting the IF analog signal to produce a first modulated radio frequency (RF) signal based on a local oscillator signal, amplifying the first RF modulated signal to produce a first RF output signal, and outputting the first RF output signal via an isolator. In a second mode of operation method may include modulation mapping the outbound data according a modulation scheme to provide second modulation mapped digital data, converting the second modulation mapped digital data to a first digital baseband signal, conditioning the first digital baseband signal to provide a first analog baseband signal, modulating one or more carriers with the first analog baseband signal to produce a second modulated RF signal based on a local oscillator signal, amplifying the second RF modulated signal to produce a second RF output signal, and outputting the second RF output signal via the isolator. The digital baseband signal may comprise an in-phase (I) digital baseband signal and a quadrature (Q) baseband signal.

  2. Radio Journalism.

    Science.gov (United States)

    Bittner, John R.; Bittner, Denise A.

    This book, a how-to-do-it guide for the novice and the professional alike, deals with several aspects of radio journalism: producing documentaries, preparing and announcing radio news, ethics and responsibility, regulation of radio journalism, and careers. It traces the history and growth of radio news, shows its impact on the public, and…

  3. Status of Radio Ice Cherenkov Experiment (RICE)

    CERN Document Server

    Allen, C; Besson, D; Frichter, G; Kotov, S A; Kravchenko, I V; McKay, D; Miller, T; Piccirillo, L; Ralston, J P; Seckel, D; Seunarine, S; Spiczak, G M

    1997-01-01

    RICE is designed to detect ultrahigh energy (>100 TeV) neutrinos from astrophysical sources. It will consist of an array of compact radio (100 to 1000 MHz) receivers buried in ice at the South Pole. During the 1995-96 and 1996-97 austral summers, several receivers transmitters were deployed in bore holes drilled for the AMANDA project, at depths of 141 to 260 m. This was the first in situ test of radio receivers in deep ice for neutrino astronomy.

  4. Integrated Optical Transmitter and Receiver

    Science.gov (United States)

    1981-09-18

    Laser Development --Further laser development await the servicing of the GaAlAs/GaAs MOCVD reactor (see section D). During this period, work focused on continued high-speed measurements of narrow-diffused stripe laser structures grown by MOCVD, to be implemented into the integrated transmitter structure. Problems Encountered and/or Anticipated Work continued on isolating causes for growth control problems encountered last month on the GaAlAs/GaAs MOCVD system. These include inability to accurately tune the properties of the GaAlAs

  5. Models of ionospheric VLF absorption of powerful ground based transmitters

    Science.gov (United States)

    Cohen, M. B.; Lehtinen, N. G.; Inan, U. S.

    2012-12-01

    Ground based Very Low Frequency (VLF, 3-30 kHz) radio transmitters play a role in precipitation of energetic Van Allen electrons. Initial analyses of the contribution of VLF transmitters to radiation belt losses were based on early models of trans-ionospheric propagation known as the Helliwell absorption curves, but some recent studies have found that the model overestimates (by 20-100 dB) the VLF energy reaching the magnetosphere. It was subsequently suggested that conversion of wave energy into electrostatic modes may be responsible for the error. We utilize a newly available extensive record of VLF transmitter energy reaching the magnetosphere, taken from the DEMETER satellite, and perform a direct comparison with a sophisticated full wave model of trans-ionospheric propagation. Although the model does not include the effect of ionospheric irregularities, it correctly predicts the average total power injected into the magnetosphere within several dB. The results, particularly at nighttime, appear to be robust against the variability of the ionospheric electron density. We conclude that the global effect of irregularity scattering on whistler mode conversion to quasi-electrostatic may be no larger than 6 dB.

  6. 49 CFR 176.150 - Radio and radar.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Radio and radar. 176.150 Section 176.150... radar. (a) Except as provided in paragraph (b) of this section, when Class 1 (explosive) materials... as radio and radar transmitters are deenergized by opening the main switches controlling the sources...

  7. NOVEL POWER CONTROL GAME VIA PRICING ALGORITHM FOR COGNITIVE RADIOS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To compensate the service providers who have paid billions of dollars to use spectrum and to satisfy secondary users’requirements in cognitive radios,a Non-cooperative Power Control Game and Pricing algorithm (NPGP) is proposed. Simulation results show that the proposed algorithm can regulate the secondary users’transmitter powers,optimally allocate radio resource and increase the total throughput effectively.

  8. The effect of multiple scattering on the aspect sensitivity and polarization of radio auroral echoes

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, E.F.; Moorcroft, D.R. (Western Ontario, University, London (Canada))

    1992-04-01

    A Monte Carlo model of radio wave scattering in the auroral electrojet has been developed to investigate multiple scattering of radio auroral echoes. Using this model, predictions of the aspect angle behavior of first-, second-, and third-order scattered power have been made. The results indicate that multiple scattering may be an important effect for VHF radars which observe the auroral E region at large magnetic aspect angles. The model shows that linearly polarized radio waves can become depolarized because of multiple scattering if the radio transmitter is horizontally polarized but not if the radio transmitter is vertically polarized. 52 refs.

  9. Radio Channel Modelling Using Stochastic Propagation Graphs

    DEFF Research Database (Denmark)

    Pedersen, Troels; Fleury, Bernard Henri

    2007-01-01

    In this contribution the radio channel model proposed in [1] is extended to include multiple transmitters and receivers. The propagation environment is modelled using random graphs where vertices of a graph represent scatterers and edges model the wave propagation between scatterers. Furthermore...

  10. Radio lighting based on dynamic chaos generators

    CERN Document Server

    Dmitriev, Alexander; Gerasimov, Mark; Itskov, Vadim

    2016-01-01

    A problem of lighting objects and surfaces with artificial sources of noncoherent microwave radiation with the aim to observe them using radiometric equipment is considered. Transmitters based on dynamic chaos generators are used as sources of noncoherent wideband microwave radiation. An experimental sample of such a device, i.e., a radio lighting lamp based on a chaos microgenerator and its performance are presented.

  11. 47 CFR 22.657 - Transmitter locations.

    Science.gov (United States)

    2010-10-01

    ... effective radiated power (ERP) of the most powerful mobile transmitter(s) in the system: Mobile unit ERP... American Datum 1983 (NAD83). Urban area N. latitude W. longitude Houston, TX 29°45′26.8″ 95°21′37.8″ New... base transmitter locations in the New York-Northeastern New Jersey urban area that utilize an antenna...

  12. Prototype of a Dsp-Based Instrument for In-Service Wireless Transmitter Power Measurement

    Directory of Open Access Journals (Sweden)

    Angrisani Leopoldo

    2014-12-01

    Full Text Available A prototype of a DSP-based instrument for in-service transmitter power measurements is presented. The instrument implements a signal-selective algorithm for power measurements that is suitable for use in wireless environments, where possible uncontrolled interfering sources are present in the radio channel and are overlapped to the signal emitted by the transmitter under test, possibly in both time and frequency domain. The measurement method exploits the principles of cyclic spectral analysis, which are briefly recalled in the paper. Potentialities, as well as limitations of the prototype use are discussed, and the results of experiments with both modulated and unmodulated interfering sources are presented.

  13. 77 FR 1779 - Emergency Locator Transmitters (ELTs)

    Science.gov (United States)

    2012-01-11

    ... Locator Transmitter (ELT) Equipment. SUMMARY: This notice announces the FAA's intent to cancel TSO-C91a, Emergency Locator Transmitter (ELT) Equipment. The effect of the cancelled TSO will result in no new TSO... existing TSO authorization (TSOA). Articles produced under an existing TSOA can still be...

  14. Radio Wavelength Transients: Current and Emerging Prospects

    CERN Document Server

    Lazio, J

    2008-01-01

    Known classes of radio wavelength transients range from the nearby--stellar flares and radio pulsars--to the distant Universe--\\gamma-ray burst afterglows. Hypothesized classes of radio transients include analogs of known objects, e.g., extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, prompt emission from \\gamma-ray bursts, evaporating black holes, and transmitters from other civilizations. A number of instruments and facilities are either under construction or in early observational stages and are slated to become available in the next few years. With a combination of wide fields of view and wavelength agility, the detection and study of radio transients will improve immensely.

  15. Hermetic diode laser transmitter module

    Science.gov (United States)

    Ollila, Jyrki; Kautio, Kari; Vahakangas, Jouko; Hannula, Tapio; Kopola, Harri K.; Oikarinen, Jorma; Sivonen, Matti

    1999-04-01

    In very demanding optoelectronic sensor applications it is necessary to encapsulate semiconductor components hermetically in metal housings to ensure reliable operation of the sensor. In this paper we report on the development work to package a laser diode transmitter module for a time- off-light distance sensor application. The module consists of a lens, laser diode, electronic circuit and optomechanics. Specifications include high acceleration, -40....+75 degree(s)C temperature range, very low gas leakage and mass-production capability. We have applied solder glasses for sealing optical lenses and electrical leads hermetically into a metal case. The lens-metal case sealing has been made by using a special soldering glass preform preserving the optical quality of the lens. The metal housings are finally sealed in an inert atmosphere by welding. The assembly concept to retain excellent optical power and tight optical axis alignment specifications is described. The reliability of the laser modules manufactured has been extensively tested using different aging and environmental test procedures. Sealed packages achieve MIL- 883 standard requirements for gas leakage.

  16. On the Capacity of Compound State-Dependent Channels with States Known at the Transmitter

    CERN Document Server

    Piantanida, Pablo

    2010-01-01

    This paper investigates the capacity of compound state-dependent channels with non-causal state information available at only the transmitter. A new lower bound on the capacity of this class of channels is derived. This bound is shown to be tight for the special case of compound channels with stochastic degraded components, yielding the full characterization of the capacity. Specific results are derived for the compound Gaussian Dirty-Paper (GDP) channel. This model consists of an additive white Gaussian noise (AWGN) channel corrupted by an additive Gaussian interfering signal, known at the transmitter only, where the input and the state signals are affected by fading coefficients whose realizations are unknown at the transmitter. Our bounds are shown to be tight for specific cases. Applications of these results arise in a variety of wireless scenarios as multicast channels, cognitive radio and problems with interference cancellation.

  17. Multi-Band Multi-Tone Tunable Millimeter-Wave Frequency Synthesizer For Satellite Beacon Transmitter

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.

    2016-01-01

    This paper presents the design and test results of a multi-band multi-tone tunable millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a satellite beacon transmitter for radio wave propagation studies at K-band (18 to 26.5 GHz), Q-band (37 to 42 GHz), and E-band (71 to 76 GHz). In addition, the architecture for a compact beacon transmitter, which includes the multi-tone synthesizer, polarizer, horn antenna, and power/control electronics, has been investigated for a notional space-to-ground radio wave propagation experiment payload on a small satellite. The above studies would enable the design of robust high throughput multi-Gbps data rate future space-to-ground satellite communication links.

  18. Radio archive

    OpenAIRE

    Street, Sean

    2008-01-01

    The Centre for Broadcasting History Research, in association with the\\ud British Universities Film and Video Council, is developing an online\\ud audio archive of UK commercial radio, from 1973 to 1992. Work produced\\ud before the Broadcasting Act 1990 represents a different ethos to the role\\ud commercial radio played, and subsequently,continues to play, in the UK.\\ud The change in commercial radio since this period is extraordinary. It is\\ud impossible for the young student of radio, born si...

  19. Correlation radio range finder

    Directory of Open Access Journals (Sweden)

    A. Sorochan

    2012-10-01

    Full Text Available In work widely known methods of range measuring are short characterized. The basic attention is given features of signal processing in a correlation method of range measuring. The signal with angular modulation with one-voice-frequency fluctuation is used as a probing signal. The absence of Doppler effect on the formation of the correlation integral, the frequency instability of the transmitter, the phase change on reflection from the target is presented. It is noticed that the result of signal processing in the range measuring instrument is reduced to formation on an exit one-voice-frequency harmonious fluctuation equal to modulating frequency that provides high characteristics of a radio range finder.

  20. Adaptive Transmitter Optimization in Multiuser Multiantenna Systems: Theoretical Limits, Effect of Delays, and Performance Enhancements

    Directory of Open Access Journals (Sweden)

    Samardzija Dragan

    2005-01-01

    Full Text Available The advances in programmable and reconfigurable radios have rendered feasible transmitter optimization schemes that can greatly improve the performance of multiple-antenna multiuser systems. Reconfigurable radio platforms are particularly suitable for implementation of transmitter optimization at the base station. We consider the downlink of a wireless system with multiple transmit antennas at the base station and a number of mobile terminals (i.e., users each with a single receive antenna. Under an average transmit power constraint, we consider the maximum achievable sum data rates in the case of (1 zero-forcing (ZF spatial prefilter, (2 modified zero-forcing (MZF spatial prefilter, and (3 triangularization spatial prefilter coupled with dirty-paper coding (DPC transmission scheme. We show that the triangularization with DPC approaches the closed-loop MIMO rates (upper bound for higher SNRs. Further, the MZF solution performs very well for lower SNRs, while for higher SNRs, the rates for the ZF solution converge to the MZF rates. An important impediment that degrades the performance of such transmitter optimization schemes is the delay in channel state information (CSI. We characterize the fundamental limits of performance in the presence of delayed CSI and then propose performance enhancements using a linear MMSE predictor of the CSI that can be used in conjunction with transmitter optimization in multiple-antenna multiuser systems.

  1. Optimal power allocation of a single transmitter-multiple receivers channel in a cognitive sensor network

    KAUST Repository

    Ayala Solares, Jose Roberto

    2012-08-01

    The optimal transmit power of a wireless sensor network with one transmitter and multiple receivers in a cognitive radio environment while satisfying independent peak, independent average, sum of peak and sum of average transmission rate constraints is derived. A suboptimal scheme is proposed to overcome the frequency of outages for the independent peak transmission rate constraint. In all cases, numerical results are provided for Rayleigh fading channels. © 2012 IEEE.

  2. Truth-value transmittal fuzzy reasoning interpolator

    Institute of Scientific and Technical Information of China (English)

    YAN Jianping; LEUNG Yee

    2005-01-01

    In this paper, we firstly associate fuzzy reasoning algorithm with the interpolation algorithm and discuss the limitation of defuzzification methods used commonly in the fuzzy reasoning algorithm. Secondly, we give a new fuzzy reasoning algorithm in case of single input, called the truth-value transmittal method, and discuss its properties. Finally, we analyze the rationality to adopy the truth-value transmittal method as the defuzzification method of full implication triple I method, and show that although CRI and triple I fuzzy reasoning method are different from fuzzy output set, they are uniform finally under the truth-value transmittal defuzzification method.

  3. INDIVIDUAL COMMUNICATION TRANSMITTER IDENTIFICATION BASED ON MULTIFRACTAL ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    Ren Chunhui; Wei Ping; Lou Zhiyou; Xiao Xianci

    2005-01-01

    In this letter, the communication transmitter transient signals are analyzed based on the time-variant hierarchy exponents of multifractal analysis. The species of optimized sample set is selected as the template of transmitter identification, so that the individual communication transmitter identification can be realized. The turn-on signals of four transmitters are used in the simulation. The experimental results show that the multifractal character of transmitter transient signals is an effective character of individual transmitter identification.

  4. Multiple-input multiple-output wavelet packet modulation based software-defined radio transceiver design

    OpenAIRE

    Cribbs, Michael R.

    2015-01-01

    Approved for public release; distribution is unlimited In this thesis, a software-defined radio (SDR) transmitter and receiver is developed using GNU Radio. The designed SDR multiplexes orthogonal subcarriers using wavelet packet modulation (WPM). WPM achieves subcarrier orthogonality by employing the inverse discrete wavelet packet transform (IDWPT) for the transmitter and discrete wavelet packet transform (DWPT) for the receiver. Realization concerns for the IDWPT and DWPT are discussed ...

  5. Decentralized SINR Balancing in Cognitive Radio Networks

    KAUST Repository

    Dhifallah, Oussama Najeeb

    2016-07-07

    This paper considers the downlink of a cognitive radio (CR) network formed by multiple primary and secondary transmitters, where each multi-antenna transmitter serves a pre-known set of single-antenna users. The paper assumes that the secondary and primary transmitters can transmit simultaneously their data over the same frequency bands, so as to achieve a high system spectrum efficiency. The paper considers the downlink balancing problem of maximizing the minimum signal-to-interference-plus noise ratio (SINR) of the secondary transmitters subject to both total power constraint of the secondary transmitters, and maximum interference constraint at each primary user due to secondary transmissions. The paper proposes solving the problem using the alternating direction method of multipliers (ADMM), which leads to a distributed implementation through limited information exchange across the coupled secondary transmitters. The paper additionally proposes a solution that guarantees feasibility at each iteration. Simulation results demonstrate that the proposed solution converges to the centralized solution in a reasonable number of iterations.

  6. Quantum Communications Transmitter at 775 nm Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel new architecture for a quantum communications laser transmitter that is designed for free-space polarization encoded quantum key distribution...

  7. Digital transmitter for data bus communications system

    Science.gov (United States)

    Proch, G. E. (Inventor)

    1975-01-01

    An improved digital transmitter for transmitting serial pulse code modulation (pcm) data at high bit rates over a transmission line is disclosed. When not transmitting, the transmitter features a high output impedance which prevents the transmitter from loading the transmission line. The pcm input is supplied to a logic control circuit which produces two discrete logic level signals which are supplied to an amplifier. The amplifier, which is transformer coupled to the output isolation circuitry, converts the discrete logic level signals to two high current level, ground isolated signals in the secondary windings of the coupling transformer. The latter signals are employed as inputs to the isolation circuitry which includes two series transistor pairs operating into a hybrid transformer functioning to isolate the transmitter circuitry from the transmission line.

  8. World War II Weather Record Transmittances

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World War II Weather Record Transmittances are a record of the weather and meteorological data observed during World War II and transferred to the archive. It...

  9. Effect of hunter selectivity on harvest rates of radio-collared white-tailed deer in Pennsylvania

    Science.gov (United States)

    Buderman, Frances E.; Diefenbach, Duane R.; Rosenberry, C.S.; Wallingford, Bret D.; Long, Eric S.

    2014-01-01

    Radio transmitters are a commonly used tool for monitoring the fates of harvested species, although little research has been devoted to whether a visible radio transmitter changes a hunters' willingness to harvest that animal. We initially surveyed deer hunters to assess their willingness to harvest radio-collared deer and predicted radio collars were unlikely to affect the harvest of antlerless deer, but hunters may be less willing to harvest small-antlered males with radio collars compared to large-antlered males. We fitted white-tailed deer (Odocoileus virginianus) with radio collars that were visible to hunters or with ear-tag transmitters or ear-tags that were difficult to detect visually and estimated if harvest rates differed among marking methods. For females, the best model failed to detect an effect of radio collars on harvest rates. Also, we failed to detect a difference between male deer fitted with radio collars and ear-tag transmitters. When we compared males fitted with radio collars versus ear tags, we found harvest rate patterns were opposite to our predictions, with lower harvest rates for adult males fitted with radio collars and higher harvest rates for yearling males fitted with radio collars. Our study suggests that harvest rate estimates generated from a sample of deer fitted with visible radio collars can be representative of the population of inference. 

  10. Microwave reconstruction method using a circular antenna array cooperating with an internal transmitter

    Science.gov (United States)

    Zhou, Huiyuan; Narayanan, Ram M.; Balasingham, Ilangko

    2016-05-01

    This paper addresses the detection and imaging of a small tumor underneath the inner surface of the human intestine. The proposed system consists of an around-body antenna array cooperating with a capsule carrying a radio frequency (RF) transmitter located within the human body. This paper presents a modified Levenberg-Marquardt algorithm to reconstruct the dielectric profile with this new system architecture. Each antenna around the body acts both as a transmitter and a receiver for the remaining array elements. In addition, each antenna also acts as a receiver for the capsule transmitter inside the body to collect additional data which cannot be obtained from the conventional system. In this paper, the synthetic data are collected from biological objects, which are simulated for the circular phantoms using CST studio software. For the imaging part, the Levenberg-Marquardt algorithm, which is a kind of Newton inversion method, is chosen to reconstruct the dielectric profile of the objects. The imaging process involves a two-part innovation. The first part is the use of a dual mesh method which builds a dense mesh grid around in the region around the transmitter and a coarse mesh for the remaining area. The second part is the modification of the Levenberg-Marquardt method to use the additional data collected from the inside transmitter. The results show that the new system with the new imaging algorithm can obtain high resolution images even for small tumors.

  11. Assessment of Barotrauma from Rapid Decompression of Depth-Acclimated Juvenile Chinook Salmon Bearing Radiotelemetry Transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard S.; Carlson, Thomas J.; Welch, Abigail E.; Stephenson, John R.; Abernethy, Cary S.; Ebberts, Blaine D.; Langeslay, Mike; Ahmann, Martin L.; Feil, Daniel H.; Skalski, J. R.; Townsend, Richard L.

    2009-11-01

    This study investigated the mortality of and injury to juvenile Chinook salmon Oncorhynchus tshawytscha exposed to simulated pressure changes associated with passage through a large Kaplan hydropower turbine. Mortality and injury varied depending on whether a fish was carrying a transmitter, the method of transmitter implantation, the depth of acclimation, and the size of the fish. Juvenile Chinook salmon implanted with radio transmitters were more likely than those without to die or sustain injuries during simulated turbine passage. Gastric transmitter implantation resulted in higher rates of injury and mortality than surgical implantation. Mortality and injury increased with increasing pressure of acclimation. Injuries were more common in subyearling fish than in yearling fish. Gas emboli in the gills and internal hemorrhaging were the major causes of mortality. Rupture of the swim bladder and emphysema in the fins were also common. This research makes clear that the exposure of juvenile Chinook salmon bearing radiotelemetry transmitters to simulated turbine pressures with a nadir of 8-19 kPa can result in barotrauma, leading to immediate or delayed mortality. The study also identified sublethal barotrauma injuries that may increase susceptibility to predation. These findings have significant implications for many studies that use telemetry devices to estimate the survival and behavior of juvenile salmon as they pass through large Kaplan turbines typical of those within the Columbia River hydropower system. Our results indicate that estimates of turbine passage survival for juvenile Chinook salmon obtained with radiotelemetry devices may be negatively biased.

  12. HF radio systems and circuits

    CERN Document Server

    Sabin, William

    1998-01-01

    A comprehensive reference for the design of high frequency communications systems and equipment. This revised edition is loaded with practical data, much of which cannot be found in other reference books. Its approach to the subject follows the needs of an engineer from system definition and performance requirements down to the individual circuit elements that make up radio transmitters and receivers. The accompanying disk contains updated software on filters, matching networks and receiver analysis. SciTech Publishing also provides many other products related to Communication Systems Design.

  13. Radio Eska Lodz, Commercial Radio As a Local Radio

    OpenAIRE

    Szews, Przemysław

    2015-01-01

    The article discusses aspects of network-based local radio using the example of Radio Eska Lodz. The author responds to questions about whether a commercial network radio station can fulfill the functions of local radio and on what this locality is actually based. In this respect, Radio Eska Lodz is characterized as part of the most popular commercial radio network in Poland. The introduction focuses on the process of transformation that local radio stations are undergoing, along with its gen...

  14. Solar Radio

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists monitor the structure of the solar corona, the outer most regions of the Sun's atmosphere, using radio waves (100?s of MHz to 10?s of GHz). Variations in...

  15. Direct RF modulation transmitter, sampling clock frequency setting method for direct RF modulation transmitter

    NARCIS (Netherlands)

    Fukuda, Shuichi; Nauta, Bram

    2013-01-01

    PROBLEM TO BE SOLVED: To provide a direct RF modulation transmitter capable of satisfying a radiation level regulation even without providing a SAW filter. SOLUTION: A direct RF modulation transmitter includes: digital/RF converters 105, 106 to which an I digital baseband signal, a Q digital baseb

  16. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Directory of Open Access Journals (Sweden)

    Huege Tim

    2017-01-01

    Full Text Available Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this “beacon correction” using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  17. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Science.gov (United States)

    Huege, Tim

    2017-03-01

    Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  18. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    CERN Document Server

    Huege, Tim

    2016-01-01

    Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for event-by-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  19. Performance Analysis of Multiradio Transmitter with Polar or Cartesian Architectures Associated with High Efficiency Switched-Mode Power Amplifiers (invited paper

    Directory of Open Access Journals (Sweden)

    F. Robert

    2010-12-01

    Full Text Available This paper deals with wireless multi-radio transmitter architectures operating in the frequency band of 800 MHz – 6 GHz. As a consequence of the constant evolution in the communication systems, mobile transmitters must be able to operate at different frequency bands and modes according to existing standards specifications. The concept of a unique multiradio architecture is an evolution of the multistandard transceiver characterized by a parallelization of circuits for each standard. Multi-radio concept optimizes surface and power consumption. Transmitter architectures using sampling techniques and baseband ΣΔ or PWM coding of signals before their amplification appear as good candidates for multiradio transmitters for several reasons. They allow using high efficiency power amplifiers such as switched-mode PAs. They are highly flexible and easy to integrate because of their digital nature. But when the transmitter efficiency is considered, many elements have to be taken into account: signal coding efficiency, PA efficiency, RF filter. This paper investigates the interest of these architectures for a multiradio transmitter able to support existing wireless communications standards between 800 MHz and 6 GHz. It evaluates and compares the different possible architectures for WiMAX and LTE standards in terms of signal quality and transmitter power efficiency.

  20. Design and Implementation of HDMI Transmitter

    Directory of Open Access Journals (Sweden)

    C.Srinivasan

    2016-11-01

    Full Text Available The High-Definition Multimedia Interface is provided for transmitting digital television audio-visual signals from DVD players, set-top boxes and other audio-visual sources to television sets, projectors and other video displays. HDMI is used in various real time applications for transmitting and receiving audio-visual Signals. A transaction level model of HDMI Transmitter is designed by using System Verilog. Transaction Level Modeling methodologies promote the growth of System Level Description Language. This paper presents a HDMI Transmitter Transaction Level Modeling Design which can be used to easily transform to HDL descriptions for subsequent RTL (Register Transfer Level Design

  1. Simulation Approach for Safety Evaluation of Smart Transmitters in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yeong Jin; Jeong, Sang Yong; Kim, Hyung Tae; Choo, Jaeyul; Park, Hyun Shin; Jeong, Choong Heui [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Lee, Jea Heung [Hanbat National University, Daejeon (Korea, Republic of)

    2015-10-15

    Smart transmitters which are microprocessor-based device including software have been used for various industry. The necessity of preparing the regulatory guide or safety review plan for the smart transmitter is increased before using the smart transmitter for safety function. So the two year simulated approach study plan to extract some generic characteristics not limited typical smart transmitter was setup in Dec. 2014 to safety evaluation of safety grade smart transmitter. This paper addresses the considerations on safety evaluation and simulated approach for smart transmitter of the first year and middle of the second year study. This paper showed the first year and the middle of the second year activity for the smart transmitter safety evaluation and simulated approach. The PC-smart transmitter test bed was setup and the test case for confirming the characteristics of the smart transmitter has been established.

  2. Software Radio Sampling Rate Selection, Design and Synchronization

    CERN Document Server

    Venosa, Elettra; Palmieri, Francesco A N

    2012-01-01

    Software Radio represents the future of communication devices. By moving a radio's hardware functionalities into software, SWR promises to change the communication devices creating radios that, built on DSP based hardware platforms, are multiservice, multiband, reconfigurable and reprogrammable. This book describes the design of Software Radio (SWR). Rather than providing an overview of digital signal processing and communications, this book focuses on topics which are crucial in the design and development of a SWR, explaining them in a very simple, yet precise manner, giving simulation results that confirm the effectiveness of the proposed design.  Readers will gain in-depth knowledge of key issues so they can actually implement a SWR.  Specifically the book addresses the following issues: proper low-sampling rate selection in the multi-band received signal scenario, architecture design for both software radio receiver and transmitter devices and radio synchronization. Addresses very precisely the most imp...

  3. Radio astronomy

    CERN Document Server

    Alder, Berni

    1975-01-01

    Methods in Computational Physics, Volume 14: Radio Astronomy is devoted to the role of the digital computer both as a control device and as a calculator in addressing problems related to galactic radio noise. This volume contains four chapters and begins with a technical description of the hardware and the special data-handling problems of using radioheliography, with an emphasis on a selection of observational results obtained with the Culgoora radioheliograph and their significance to solar physics and to astrophysics in general. The subsequent chapter examines interstellar dispersion, i

  4. TLEs and early VLF events: Simulating the important impact of transmitter-disturbance-receiver geometry

    Science.gov (United States)

    NaitAmor, S.; Ghalila, H.; Cohen, M. B.

    2017-01-01

    Early very low frequency (VLF) events are perturbations to subionospherically propagating VLF radio transmitters which sometimes occur when lightning activity is near the transmitter-receiver path. They are often correlated to Transient Luminous Events (TLEs). Recent analysis have focused on a new type of early events whose recovery time persists for many minutes, called LOng Recovery Events (LOREs). The underlying cause of these events is still unclear. Curiously, LOREs sometimes appear on only one path, while the same event observed on a different transmitter-receiver path does not indicate a LORE. In this paper we observe and simulate two cases of early signal perturbations: The first is a typical early VLF event, and the second is a LORE. Both were recorded by two AWESOME VLF receivers in North Africa on 12 December 2009, during the EuroSprite campaign. We combine observations with theoretical modeling to infer the electron density change that most closely reproduces the observed perturbation. Our results explain the cases where LOREs are detected on only one path as resulting from transmitter-receiver geometry significantly which impacts the modal content and therefore the observed VLF recovery time.

  5. Integrated Inductors for RF Transmitters in CMOS/MEMS Smart Microsensor Systems

    Science.gov (United States)

    Kim, Jong-Wan; Takao, Hidekuni; Sawada, Kazuaki; Ishida, Makoto

    2007-01-01

    This paper presents the integration of an inductor by complementary metal-oxide-semiconductor (CMOS) compatible processes for integrated smart microsensor systems that have been developed to monitor the motion and vital signs of humans in various environments. Integration of radio frequency transmitter (RF) technology with complementary metal-oxide-semiconductor/micro electro mechanical systems (CMOS/MEMS) microsensors is required to realize the wireless smart microsensors system. The essential RF components such as a voltage controlled RF-CMOS oscillator (VCO), spiral inductors for an LC resonator and an integrated antenna have been fabricated and evaluated experimentally. The fabricated RF transmitter and integrated antenna were packaged with subminiature series A (SMA) connectors, respectively. For the impedance (50 Ω) matching, a bonding wire type inductor was developed. In this paper, the design and fabrication of the bonding wire inductor for impedance matching is described. Integrated techniques for the RF transmitter by CMOS compatible processes have been successfully developed. After matching by inserting the bonding wire inductor between the on-chip integrated antenna and the VCO output, the measured emission power at distance of 5 m from RF transmitter was -37 dBm (0.2 μW).

  6. Analysis of power efficiencies of polar transmitter and HPA in OFDM communication system

    Science.gov (United States)

    Ryu, Heung-Gyoon

    2014-02-01

    Polar transmitter is known as good candidates for high data rate systems such as OFDM (orthogonal frequency division multiplexing) because they can obtain high-efficiency switched-mode radio frequency (RF) power amplifiers. But it is important to consider the nonlinear effects and power efficiency of the amplifier in the OFDM communication systems. High PAPR (peak-to-average power ratio) causes performance degradation by non-linear distortion in OFDM communication system. So to avoid non-linear distortion, back-off is needed. In addition, output of amplifier is lower and the power efficiency is reduced because of back-off. In this article, we compare PAE (power added efficiency) of polar transmitter in OFDM system and PAE of HPA (high power amplifier) in OFDM system. Also, we analyse PAE according to back-off in DFT-spread OFDM (discrete Fourier transform-spread OFDM), which is PAPR reduction method and we compare with PAE of polar transmitter in OFDM system. And we analyse output spectrum of OFDM and DFT-spread OFDM system. Through spectrum analysis, we analyse PAE of OFDM and DFT-spread OFDM, which is satisfied with output spectrum mask of 3rd generation long term evolution (3G LTE) and also compare with PAE polar transmitter of OFDM system, which is satisfied with spectrum mask. Finally, we analyse PAE according to modulation method and analyse PAE of OFDM and DFT-spread OFDM at same bit error rate.

  7. Agricultural applications of NIR reflectance and transmittance

    DEFF Research Database (Denmark)

    Gislum, René

    2009-01-01

    There has been a considerable increase in the use of near infrared (NIR) reflectance and transmittance spectroscopy technologies for rapid determination of quality parameters in agriculture, including applications within crop product quality, feed and food quality, manure quality, soil analyses etc...

  8. Transmitter systems in the primate dentate gyrus.

    Science.gov (United States)

    Amaral, D G; Campbell, M J

    1986-01-01

    While the dentate gyrus is clearly the simplest of the cortical fields that constitute the hippocampal formation, it nonetheless occupies a pivotal position in the flow of information through this region. Though it has been the subject of anatomical study for over a century and its major connections have been known for almost as long, the use of newly developed histochemical and immunohistochemical techniques have demonstrated many new facets of its intrinsic connectivity and afferent innervation. These techniques have established that it is innervated by cholinergic, noradrenergic, serotonergic and dopaminergic fibers. More recent studies have shown that fibers and cell bodies of the dentate gyrus are immunoreactive for variety of neuroactive substances including the excitatory amino acids glutamate and aspartate, the inhibitory transmitter GABA, as well as peptides of many types including the opioid peptides, enkephalin and dynorphin, several forms of somatostatin, neuropeptide Y, cholycystokinin, vasoactive intestinal peptide and substance P. In this review, we will briefly summarize the distribution of each of these putative transmitter systems within the dentate gyrus. The perspective emerges that the plethora of newly identified and chemically specific fiber systems enriches the classical understanding of the organization of this relatively simple cortical structure. Since there is thus far no evidence for the exclusion from the dentate gyrus of any class of transmitter bearing fiber or neuron found in the neocortex, it can be viewed as a relatively simple model system for studying the interactions of specific transmitter systems in a laminated, cortical structure.

  9. Digitale radio

    NARCIS (Netherlands)

    Schiphorst, Roel; Zondervan, L.

    2007-01-01

    Als eerste in Europa heeft Nederland begin december 2006 de omschakeling van analoge naar digitale ethertelevisie gemaakt. Voor de analoge FM-radio is er ook een digitale variant, T-DAB. T-DAB staat voor 'Terrestrial Digital Audio Broadcasting'. Dit artikel gaat verder in op deze techniek en de veld

  10. Single-Chip Fully Integrated Direct-Modulation CMOS RF Transmitters for Short-Range Wireless Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen

    2013-08-01

    Full Text Available Ultra-low power radio frequency (RF transceivers used in short-range application such as wireless sensor networks (WSNs require efficient, reliable and fully integrated transmitter architectures with minimal building blocks. This paper presents the design, implementation and performance evaluation of single-chip, fully integrated 2.4 GHz and 433 MHz RF transmitters using direct-modulation power voltage-controlled oscillators (PVCOs in addition to a 2.0 GHz phase-locked loop (PLL based transmitter. All three RF transmitters have been fabricated in a standard mixed-signal CMOS 0.18 µm technology. Measurement results of the 2.4 GHz transmitter show an improvement in drain efficiency from 27% to 36%. The 2.4 GHz and 433 MHz transmitters deliver an output power of 8 dBm with a phase noise of −122 dBc/Hz at 1 MHz offset, while drawing 15.4 mA of current and an output power of 6.5 dBm with a phase noise of −120 dBc/Hz at 1 MHz offset, while drawing 20.8 mA of current from 1.5 V power supplies, respectively. The PLL transmitter delivers an output power of 9 mW with a locking range of 128 MHz and consumes 26 mA from 1.8 V power supply. The experimental results demonstrate that the RF transmitters can be efficiently used in low power WSN applications.

  11. Realization of Transmitter and Receiver Architecture for Downlink Channels in 3-GPP LTE

    Directory of Open Access Journals (Sweden)

    S. Syed Ameer Abbas

    2013-03-01

    Full Text Available Long Term Evolution (LTE, the next generation of radio technologies designed to increase the capacityand speed of mobile networks. The future communication systems require much higher peak rate for the airinterface but very short processing delay. This paper mainly focuses on to improve the processing speedand capability and decrease the processing delay ofthe downlink channels using the parallel processingtechnique. This paper proposes Parallel ProcessingArchitecture for both transmitter and receiver forDownlink channels in 3GPP-LTE. The Processing stepsinclude Scrambling, Modulation, Layer mapping,Precoding and Mapping to the REs in transmitter side. Similarly demapping from the REs, Decoding andDetection, Delayer mapping and Descrambling in Receiver side. Simulation is performed by usingmodelsim and Implementation is achieved using PlanAhead tool and virtex 5 FPGA.Implemented resultsare discussed in terms of RTL design, FPGA editor,power estimation and resource estimation.

  12. Mortality, Transmitter Retention, Growth, and Wound Healing in Juvenile Salmon Injected with Micro Acoustic Transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Liss, Stephanie A.; Brown, Richard S.; Deters, Katherine A.; Walker, Ricardo W.; Deng, Z. Daniel; Eppard, M. Brad; Townsend, Richard L.; Seaburg, Adam G.

    2016-07-28

    A cylindrical acoustic transmitter (AT; 0.2 g) has been developed for injection into the peritoneum of fish. Laboratory studies can provide tagging guidelines to minimize the effect of implantation techniques and transmitter burden (relative weight of the transmitter to the weight of the fish) in fish before a transmitter is used in field studies. The goal of this study was to examine response variables (mortality, transmitter expulsion, growth, wound area) of juvenile Chinook Salmon (Oncorhynchus tschawytscha; 65–104 mm fork length [FL]) injected with an AT along a wide range of sizes that could lead to a guideline for minimizing tagging effects. The overarching goal was to determine a minimum size threshold for fish that can be injected, while minimizing adverse transmitter effects. Juveniles (n = 700) were separated into four treatments: (1) acoustic transmitter injection (AT), (2) AT and a passive integrated transponder tag injection (AT+PIT), (3) visual implant elastomer injection (Marked control), and (4) unmarked (Unmarked control). Fish were evaluated weekly for four weeks, and again at the end of the study (60 d post-tagging). Fish injected with an AT or an AT+PIT experienced greater mortality than Marked controls. By 60 d post-tagging, transmitter expulsion was 44% for AT fish and 20% for AT+PIT fish. Fish injected with an AT or an AT+PIT grew (FL and weight gain) significantly less than Marked controls, and no minimum size thresholds were detected. Finally, initial size (FL) significantly affected wound area in AT and AT+PIT fish. A size threshold was only identified on Day 7 (85.1 mm) for AT+PIT fish, indicating that wound areas in fish < 85.1 mm were larger than wound areas of fish > 85.1 mm. This research suggests that injecting juveniles with an AT or an AT+PIT had a greater effect on smaller fish than larger fish.

  13. Radio Ljubljana and its music policies 1928-1941

    Directory of Open Access Journals (Sweden)

    Stefanija Leon

    2016-01-01

    Full Text Available The main programming issue faced by Radio Ljubljana was connected to its function: was it a new medium basically intended for cultural advancement and democratic information distribution or was it a new medium primarily serving as an entertainment platform for different types of listener? The question had been one of the key topics from the beginnings of Radio Ljubljana’s broadcasting in 1928. This paper discusses the answers to this question through an analysis of the musical programming from 1928 until the Luftwaffe destroyed Radio Ljubljana’s transmitter in Domžale on April 11, 1941.

  14. Implementation of Universal Asynchronous Receiver and Transmitter

    Directory of Open Access Journals (Sweden)

    Payata Srikanth Yadav

    2015-03-01

    Full Text Available Universal Asynchronous Receiver Transmitter (UART is the serial communication protocol that is used for data exchange between computer & peripherals. UART is a low velocity, short-distance, low-cost protocol. UART includes three modules which are received, the baud rate generator and transmitter. The UART design with Very High Description Language can be integrated into the Field Programmable Gate Array to achieve stable data transmission and to make system reliable and compact. In the result and simulation part, this project will focus on check the receive data with error free & baud rate generation at different frequencies. Before synthesizing of UART a baud rate generator is incorporated into the system. We use the frequency divider which sets itself to required frequency for the functionality at lower frequency. All modules are designed using VERILOG and implemented on Xilinx Suite development board.

  15. Analog Dithering Techniques for Wireless Transmitters

    CERN Document Server

    Arfaei Malekzadeh, Foad; Roermund, Arthur H M

    2013-01-01

    This book describes innovative techniques and the theoretical background for design and analysis of high performance RF/Microwave transmitters. It introduces new, robust   linearization/efficiency enhancement techniques, applicable to all of the switched mode power amplifiers. Novel analysis methods associated with these new techniques are also introduced and supporting measurement results are documented.  Innovative graphical representation methods are used to help the reader understand the matter intuitively.  Applications for the techniques discussed are very extensive, ranging from data convertors to RF/Microwave/mm-wave wireless/wire line transmitters. The authors have avoided using lengthy formulas in the discussion and have used an intuitive and simple approach to go through the necessary details.  Readers will gain valuable understanding of the dither phenomenon, its mechanism, effect and undesired side effects. The novel architectures introduced are simple, don’t require complicated DSP techni...

  16. A solid state transmitter with adaptive beamforming

    Science.gov (United States)

    Wallington, J. R.; Chrystie, P. J.

    In many transmitter applications it is desirable to provide low sidelobe streerable radiation patterns from an array fed by multiple identical solid state sources. A feed network for an experimental linear array which allows this to be accomplished by means of 'phase shift only' control of array element amplitude and phase is described. Details of the experimental equipment and measured radiation patterns, in both the transmit and receive mode, are presented.

  17. 5 Watt, Solid State, EHF Transmitter.

    Science.gov (United States)

    2014-09-26

    satellite-communication ground terminals. This state-of- the- art transmitter demonstrates efficient and cost-effective RF power generation at EHF for...are relatively little or no spectrum allocation problems, is that the state-of-the- art in RF power generation is far below the required levels for...accomplished using E-H hybrid magic tees of reduced height waveguide with good balance and isolation characteristics. Modulation and other signal

  18. The Radio JOVE Project - Shoestring Radio Astronomy

    Science.gov (United States)

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

    2010-01-01

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

  19. The Radio JOVE Project - Shoestring Radio Astronomy

    Science.gov (United States)

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

    2010-01-01

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

  20. Classical transmitters and their receptors in flatworms.

    Science.gov (United States)

    Ribeiro, P; El-Shehabi, F; Patocka, N

    2005-01-01

    The flatworm nervous system employs a wide repertoire of neuroactive substances, including small chemical messengers, the so called classical transmitters, and several types of neuropeptides. A large body of research accumulated over four decades has provided a wealth of information on the tissue localization and effects of these substances, their biochemistry and, recently, their molecular modes of action in all major classes of flatworms. This evidence will be reviewed, with particular emphasis on the small (classical) transmitters and the receptors that mediate their effects. One of the themes that will emerge from this discussion is that classical transmitters regulate core activities such as movement, metabolism and transport, and thus are essential for survival of the organism. In addition, the evidence shows that flatworms have multiple neurotransmitter receptors, many with unusual pharmacological features, which make them particularly attractive as drug targets. Understanding the molecular basis of these distinctive properties, and developing new, more specific receptor agonists and antagonists will undoubtedly become a major challenge in future research.

  1. Space Telecommunications Radio System STRS Cognitive Radio

    Science.gov (United States)

    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.

  2. A standard operating procedure for the surgical implantation of transmitters in juvenile salmonids

    Science.gov (United States)

    Liedtke, T.L.; Beeman, J.W.; Gee, L.P.

    2012-01-01

    Biotelemetry is a useful tool to monitor the movements of animals and is widely applied in fisheries research. Radio or acoustic technology can be used, depending on the study design and the environmental conditions in the study area. A broad definition of telemetry also includes the use of Passive Integrated Transponder (PIT) tags, either separately or with a radio or acoustic transmitter. To use telemetry, fish must be equipped with a transmitter. Although there are several attachment procedures available, surgical implantation of transmitters in the abdominal cavity is recognized as the best technique for long-term telemetry studies in general (Stasko and Pincock, 1977; Winter, 1996; Jepsen, 2003), and specifically for juvenile salmonids, Oncorhynchus spp. (Adams and others, 1998a, 1998b; Martinelli and others, 1998; Hall and others, 2009). Studies that use telemetry assume that the processes by which the animals are captured, handled, and tagged, as well as the act of carrying the transmitter, will have minimal effect on their behavior and performance. This assumption, commonly stated as a lack of transmitter effects, must be valid if telemetry studies are to describe accurately the movements and behavior of an entire population of interest, rather than the subset of that population that carries transmitters. This document describes a standard operating procedure (SOP) for surgical implantation of radio or acoustic transmitters in juvenile salmonids. The procedures were developed from a broad base of published information, laboratory experiments, and practical experience in tagging thousands of fish for numerous studies of juvenile salmon movements near Columbia River and Snake River hydroelectric dams. Staff from the Western Fisheries Research Center's Columbia River Research Laboratory (CRRL) frequently have used telemetry studies to evaluate new structures or operations at hydroelectric dams in the Columbia River Basin, and these evaluations typically

  3. Wave Optics Based LEO-LEO Radio Occultation Retrieval

    DEFF Research Database (Denmark)

    von Benzon, Hans-Henrik; Høeg, Per

    2016-01-01

    This paper describes the theory for performing retrieval of radio occultations that use probing frequencies in the XK and KM band. Normally radio occultations use frequencies in the L band and GPS satellites are used as the transmitting source and the occultation signals are received by a GPS...... in the signal amplitude caused by atmospheric absorption. The radio wave transmitter is placed on one of these satellites while the receiver is placed on the other LEO satellite. One of the drawbacks of normal GPS based radio occultations is that external information is needed to calculate some...... chain is therefore a wave optics based retrieval chain and it is therefore possible to process measurements that include multipath. In this paper simulated LEO to LEO radio occultations based on 5 different frequencies are used. The 5 frequencies are placed in the XK or KM frequency band. This new wave...

  4. Temperature and temporal dependence of neutral density transmittance standards

    Science.gov (United States)

    Koo, A.; Hamlin, J. D.

    2012-04-01

    The Schott series of NG glasses are frequently used to manufacture neutral density transmittance standards for validation of spectrophotometer systems as well as for comparisons of regular spectral transmittance scales. A study has been made of the temperature and temporal dependence of transmittance in these types of filters. The temperature dependence of transmittance is found to scale as -ln(T). The filter transmittance was found to vary significantly with time shortly after manufacture but appears to be stabilizing nine months after beginning measurements.

  5. Measurement method for light transmittance of layered metamaterials.

    Science.gov (United States)

    Isozaki, Akihiro; Kan, Tetsuo; Ajiki, Yoshiharu; Matsumoto, Kiyoshi; Shimoyama, Isao

    2013-06-01

    We propose a method to measure light transmittance of layered metamaterials by placing the metamaterials directly on a Si photodiode. Our measurement method enables the direct detection of transmitted light that appears as an evanescent wave in natural materials. Here, we report the transmittance measurements of a typical metamaterial using this method. The metamaterial was composed of Ag/Al(2)O(3) layers and was fabricated by direct evaporation on the Si photodiode. The measured transmittance agrees with the simulated transmittance. Our results confirmed that this measurement method can determine the transmittance properties of metamaterials and that it is applicable to other types of metamaterials.

  6. Influence of Incision Location on Transmitter Loss, Healing, Incision Lengths, Suture Retention, and Growth of Juvenile Chinook Salmon

    Energy Technology Data Exchange (ETDEWEB)

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greggory L.; Woodley, Christa M.; Deters, Katherine A.

    2010-05-11

    In this study, conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, we measured differences in survival and growth, incision openness, transmitter loss, wound healing, and erythema among abdominal incisions on the linea alba, lateral and parallel to the linea alba (muscle-cutting), and following the underlying muscle fibers (muscle-sparing). A total of 936 juvenile Chinook salmon were implanted with both Juvenile Salmon Acoustic Tracking System transmitters (0.43 g dry) and passive integrated transponder tags. Fish were held at 12°C (n = 468) or 20°C (n = 468) and examined once weekly over 98 days. We found survival and growth did not differ among incision groups or between temperature treatment groups. Incisions on the linea alba had less openness than muscle-cutting and muscle-sparing incisions during the first 14 days when fish were held at 12°C or 20°C. Transmitter loss was not different among incision locations by day 28 when fish were held at 12°C or 20°C. However, incisions on the linea alba had greater transmitter loss than muscle-cutting and muscle-sparing incisions by day 98 at 12°C. Results for wound closure and erythema differed among temperature groups. Results from our study will be used to improve fish-tagging procedures for future studies using acoustic or radio transmitters.

  7. Direct Position Determination of Multiple Radio Signals

    Directory of Open Access Journals (Sweden)

    Weiss Anthony J

    2005-01-01

    Full Text Available The most common methods for position determination of radio signal emitters such as communications or radar transmitters are based on measuring a specified parameter such as angle of arrival (AOA or time of arrival (TOA of the signal. The measured parameters are then used to estimate the transmitter's location. Since the measurements are done at each base station independently, without using the constraint that the AOA/TOA estimates at different base stations should correspond to the same transmitter's location, this is a suboptimal location determination technique. Further, if the number of array elements at each base station is , and the signal waveforms are unknown, the number of cochannel simultaneous transmitters that can be localized by AOA is limited to . Also, most AOA algorithms fail when the sources are not well angularly separated. We propose a technique that uses exactly the same data as the common AOA methods but the position determination is direct. The proposed method can handle more than cochannel simultaneous signals. Although there are many stray parameters, only a two-dimensional search is required for a planar geometry. The technique provides a natural solution to the measurements sources association problem that is encountered in AOA-based location systems. In addition to new algorithms, we provide analytical performance analysis, Cramér-Rao bounds and Monte Carlo simulations. We demonstrate that the proposed approach frequently outperforms the traditional AOA methods for unknown as well as known signal waveforms.

  8. Electromagnetic compatibility fundamentals applied to spacecraft radio communication systems

    Science.gov (United States)

    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.

  9. Acorn dispersal estimated by radio-tracking.

    Science.gov (United States)

    Pons, Josep; Pausas, Juli G

    2007-10-01

    Bird-dispersed seeds are difficult to track, especially in the case of long-distance dispersal events. To estimate the oak dispersal distance and the seed shadow generated by the European jay (Garrulus glandarius), we inserted radio-transmitters in 239 acorns, placed them in bird-feeders and then located them by radio-tracking. Using this methodology we located the exact caching site of 94 Quercus ilex and 54 Q. suber acorns and determined the caching habitat characteristics (vegetation type, distance, spatial distribution). The results show that: (1) there is no differences in the dispersal distance distribution between the different acorn species or sizes, (2) dispersal distances range from approximately 3 m up to approximately 550 m (mean = 68.6 m; median = 49.2 m), (3) recently abandoned fields and forest tracks were the sites preferred by jays to cache acorns, whereas fields and shrublands were avoided and (4) seed shadows showed acorn aggregation zones (i.e. clusters of caches) close to the feeder as well as isolated caches at longer distances. The results also suggest that radio-transmitters are a cheap and reliable way to determine seed shadows and quantify both seed dispersal and post-dispersal seed predation for medium to large seeds.

  10. Integrated Inductors for RF Transmitters in CMOS/MEMS Smart Microsensor Systems

    Directory of Open Access Journals (Sweden)

    Makoto Ishida

    2007-07-01

    Full Text Available This paper presents the integration of an inductor by complementary metal-oxide-semiconductor (CMOS compatible processes for integrated smart microsensorsystems that have been developed to monitor the motion and vital signs of humans invarious environments. Integration of radio frequency transmitter (RF technology withcomplementary metal-oxide-semiconductor/micro electro mechanical systems (CMOS/MEMS microsensors is required to realize the wireless smart microsensors system. Theessential RF components such as a voltage controlled RF-CMOS oscillator (VCO, spiralinductors for an LC resonator and an integrated antenna have been fabricated and evaluatedexperimentally. The fabricated RF transmitter and integrated antenna were packaged withsubminiature series A (SMA connectors, respectively. For the impedance (50 matching,a bonding wire type inductor was developed. In this paper, the design and fabrication of thebonding wire inductor for impedance matching is described. Integrated techniques for theRF transmitter by CMOS compatible processes have been successfully developed. Aftermatching by inserting the bonding wire inductor between the on-chip integrated antennaand the VCO output, the measured emission power at distance of 5 m from RF transmitterwas -37 dBm (0.2 μW.

  11. An efficient magnetron transmitter for superconducting accelerators

    Science.gov (United States)

    Kazakevich, G.; Lebedev, V.; Yakovlev, V.; Pavlov, V.

    2016-12-01

    A concept of a highly-efficient high-power magnetron transmitter allowing wide-band phase and the mid-frequency power control at the frequency of the locking signal is proposed. The proposal is aimed for powering Superconducting RF (SRF) cavities of intensity-frontier accelerators. The transmitter is intended to operate with phase and amplitude control feedback loops allowing suppression of microphonics and beam loading in the SRF cavities. The concept utilizes injection-locked magnetrons controlled in phase by the locking signal supplied by a feedback system. The injection-locking signal pre-excites the magnetron and allows its operation below the critical voltage in free run. This realizes control of the magnetron power in an extended range (up to 10 dB) by control of the magnetron current. Experimental studies were carried out with 2.45 GHz, 1 kW, CW magnetrons. They demonstrated stable operation of the magnetrons and the required range of power control at a low noise level. An analysis of the kinetics of the drifting charge within the framework of the presented model of phase focusing in magnetrons substantiates the concept and the experimental results.

  12. Dynamic reliability of digital-based transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Brissaud, Florent, E-mail: florent.brissaud.2007@utt.f [Institut National de l' Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France) and Universite de Technologie de Troyes - UTT, Institut Charles Delaunay - ICD and UMR CNRS 6279 STMR, 12 rue Marie Curie, BP 2060, 10010 Troyes Cedex (France); Smidts, Carol [Ohio State University (OSU), Nuclear Engineering Program, Department of Mechanical Engineering, Scott Laboratory, 201 W 19th Ave, Columbus OH 43210 (United States); Barros, Anne; Berenguer, Christophe [Universite de Technologie de Troyes (UTT), Institut Charles Delaunay (ICD) and UMR CNRS 6279 STMR, 12 rue Marie Curie, BP 2060, 10010 Troyes Cedex (France)

    2011-07-15

    Dynamic reliability explicitly handles the interactions between the stochastic behaviour of system components and the deterministic behaviour of process variables. While dynamic reliability provides a more efficient and realistic way to perform probabilistic risk assessment than 'static' approaches, its industrial level applications are still limited. Factors contributing to this situation are the inherent complexity of the theory and the lack of a generic platform. More recently the increased use of digital-based systems has also introduced additional modelling challenges related to specific interactions between system components. Typical examples are the 'intelligent transmitters' which are able to exchange information, and to perform internal data processing and advanced functionalities. To make a contribution to solving these challenges, the mathematical framework of dynamic reliability is extended to handle the data and information which are processed and exchanged between systems components. Stochastic deviations that may affect system properties are also introduced to enhance the modelling of failures. A formalized Petri net approach is then presented to perform the corresponding reliability analyses using numerical methods. Following this formalism, a versatile model for the dynamic reliability modelling of digital-based transmitters is proposed. Finally the framework's flexibility and effectiveness is demonstrated on a substantial case study involving a simplified model of a nuclear fast reactor.

  13. Radio frequency powering of microelectronic sensor modules

    Energy Technology Data Exchange (ETDEWEB)

    Boegel, Gerd vom; Meyer, Frederic; Kemmerling, Martin [Fraunhofer-Institut fuer Mikroelektronische Schaltungen und Systeme, Duisburg (Germany)

    2013-03-01

    In RFID applications the power supply of transponders via electromagnetic field is state-of-the-art. In this presentation the use of electromagnetic energy will be discussed for the operation of sensor modules. Starting with the question, whether the omnipresent radiation from power supply networks, radio transmitters, and mobile phone base stations is useable (energy harvesting), the feasibility of the operation of self-sufficient sensor modules is explained. Ancillary conditions of typical applications (e.g. operating range) and technology are considered. (orig.)

  14. Practical Coding Schemes for Cognitive Overlay Radios

    CERN Document Server

    Kurniawan, Ernest; Rini, Stefano

    2012-01-01

    We develop practical coding schemes for the cognitive overlay radios as modeled by the cognitive interference channel, a variation of the classical two user interference channel where one of the transmitters has knowledge of both messages. Inspired by information theoretical results, we develop a coding strategy for each of the three parameter regimes where capacity is known. A key feature of the capacity achieving schemes in these regimes is the joint decoding of both users' codewords, which we accomplish by performing a posteriori probability calculation over a combined trellis. The schemes are shown to perform close to the capacity limit with low error rate.

  15. Behavior of sandhill cranes harnessed with different satellite transmitters

    Science.gov (United States)

    Olsen, G.H.; Ellis, D.H.; Landfried, S.E.; Miller, L.H.; Klugman, S.S.; Fuller, M.R.; Vermillion, C.H.

    1992-01-01

    The effectiveness of various attachment methods and designs of platform transmitting terminals (PTT's) was tested on captive sandhill cranes (Grus canadensis) at the Patuxent Wildlife Research Center, Laurel, Maryland, during 1989-91. Combinations of attachment and transmitter designs included neoprene cord harness with batteries separate from the transmitter (2 harness designs), Teflon ribbon harness with batteries incorporated into the transmitter package (4 transmitter models), and a package attached directly to the bird with epoxy glue only. Physical effects seen on cranes wearing PTT's ranged from skin lacerations (caused by rubbing of harness material) to no observed effects (other than feather wear). The most successful harness material and design utilized a Teflon ribbon harness with the 4 ribbon ends from the transmitter forming a neck loop and a body loop joined at the sternum. Time spent by sandhill cranes performing most activities did not change after transmitter attachment using this harness method.

  16. ELF/VLF wave disturbances detected by the DEMETER satellite over the HAARP transmitter

    Science.gov (United States)

    Titova, Elena; Demekhov, Andrei; Parrot, Michel; Mogilevsky, Mikhail; Mochalov, Alexey; Pashin, Anatoly

    We report observations of electromagnetic the ELF/VLF wave disturbances by the DEMETER satellite (670 km altitude) overflying the HAARP heating facility (62.39(°) N, 145.15(°) W, L = 4.9). The HAARP HF transmitter operated at the maximum available power of 3.6 MW, O-mode polarization, and the beam directed towards the magnetic zenith. ELF/VLF waves caused by the HAARP heating are detected by the DEMETER satellite when the HF radio wave frequency was close to the critical frequency (foF2) of the ionospheric F2 layer but below it. ELF/VLF wave disturbances observed above the HAARP transmitter were detected by electrical antennas in an area with characteristic size 10 (2) km. We analyze amplitude and polarization spectra of the ELF disturbances and compare them with the characteristics of natural ELF hiss above HAARP. The VLF wave disturbances in the topside ionosphere above the HAARP transmitter were detected in the frequency ranges 8-17 kHz and 15-18 kHz which are close to the lower hybrid resonance frequency f _LHR in the heating region and its second harmonic (2f _LHR), respectively. In the case where the HAARP HF power was modulated, the detected VLF waves were also modulated with the same frequency whereas in the ELF frequency range the modulation period of the HAARP power was not observed. Possible mechanisms of generation of the ELF/VLF disturbances produced by the HAARP transmitter in the topside ionosphere are discussed.

  17. Abnormal Modulation of Dielectric Band Transmittance of Polystyrene Opal

    Institute of Scientific and Technical Information of China (English)

    HU Xiao-Yong; GONG Qi-Huang; CHENG Bing-Ying; ZHANG Dao-Zhong

    2005-01-01

    @@ The abnormal transmittance in the dielectric band edge of a polystyrene opal is observed and analysed. The transmittance is periodically modulated and the period of modulation varies with the wavelength, which destroys the perfect structure of the photonic band gap. The transmittance modulation originates from the propagation of the low order whispering-gallery mode excited in polystyrene spheres. These results indicate that the whisperinggallery mode has a great influence on practical applications of polystyrene opal.

  18. 47 CFR 97.313 - Transmitter power standards.

    Science.gov (United States)

    2010-10-01

    ... transmitter power exceeding 5 W PEP on the UHF 23 cm band when the control operator is a Novice operator. (f... station may transmit with a transmitter power exceeding 1.5 kW PEP. (c) No station may transmit with a transmitter power output exceeding 200 W PEP: (1) On the 10.10-10.15 MHz segment; (2) On the 3.525-3.60 MHz, 7...

  19. Thermal Design and Flight Validation for Solid-state Transmitter

    Directory of Open Access Journals (Sweden)

    Wang Lei

    2014-06-01

    Full Text Available Solid-state transmitter with large power and high heat flux is a key equipment of an HJ-1-C satellite; therefore, it has a great influence on satellite thermal design. Thermal design ensures that the solid-state transmitter works well within the allowable temperature limits of the equipment. The solid-state transmitter thermal design and solved key problems are provided in accordance with the HJ-1-C characteristics. Moreover, an analysis of satellites on orbit was performed. Based on the telemetry data, the thermal control design is shown to satisfy the temperature requirements of the solid-state transmitter.

  20. Optical Transmitter Terminal for Selective RF High Frequency Bans Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the proposal work is to investigate the highly innovative conceptual design of an optical communication selective frequency transmitter terminal...

  1. Power and Contention Control Scheme: As a Good Candidate for Interference Modeling in Cognitive Radio Network

    Directory of Open Access Journals (Sweden)

    Ireyuwa E. Igbinosa

    2015-10-01

    Full Text Available Due to the ever growing need for spectrum, the cognitive radio (CR has been proposed to improve the radio spectrum utilization. In this scenario, the secondary users (SU are permitted to share spectrum with the licensed primary users (SU with a strict condition that they do not cause harmful interference to the cognitive network. In this work, we have proposed an interference model for cognitive radio network that utilizes power or contention control interference management schemes. We derived the probability density function (PDF with the power control scheme, where the power of transmission of the CR transmitter is guided by the power control law and also with contention control scheme that has a fixed transmission power for all CR transmitter controlled by a contention control protocol. This protocol makes a decision on which CR transmitter can transmit at any point in time. In this work, we have shown that power and contention control schemes are good candidates for interference modeling in cognitive radio system. The impact of the unknown location of the primary receiver on the resulting interference generated by the CR transmitters was investigated and the results shows that the challenges of the hidden primary receivers lead to higher CR-primary interference in respect to higher mean and variance. Finally, the presented results show power control and the contention control scheme are good candidates in reducing the interference generated by the cognitive radio network.

  2. Optical Transmittance of Anodically Oxidized Aluminum Alloy

    Science.gov (United States)

    Saito, Mitsunori; Shiga, Yasunori; Miyagi, Mitsunobu; Wada, Kenji; Ono, Sachiko

    1995-06-01

    Optical transmittance and anisotropy of anodic oxide films that were made from pure aluminum and an aluminum alloy (A5052) were studied. The alloy oxide film exhibits an enhanced polarization function, particularly when anodization is carried out at a large current density. It was revealed by chemical analysis that the alloy oxide film contains a larger amount of unoxidized aluminum than the pure-aluminum oxide film. The polarization function can be elucidated by considering unoxidized aluminum particles that are arranged in the columnar structure of the alumina film. Electron microscope observation showed that many holes exist in the alloy oxide film, around which columnar cells are arranged irregularly. Such holes and irregular cell arrangement cause the increase in the amount of unoxidized aluminum, and consequently induces scattering loss.

  3. Atmospheric transmittance model for photosynthetically active radiation

    Energy Technology Data Exchange (ETDEWEB)

    Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana [Physics Department, West University of Timisoara, V Parvan 4, 300223 Timisoara (Romania); Pop, Nicolina [Department of Physical Foundations of Engineering, Politehnica University of Timisoara, V Parvan 2, 300223 Timisoara (Romania); Calinoiu, Delia [Mechanical Engineering Faculty, Politehnica University of Timisoara, Mihai Viteazu 1, 300222 Timisoara (Romania)

    2013-11-13

    A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, Ångström's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.

  4. Digital Audio Radio Broadcast Systems Laboratory Testing Nearly Complete

    Science.gov (United States)

    2005-01-01

    Radio history continues to be made at the NASA Lewis Research Center with the completion of phase one of the digital audio radio (DAR) testing conducted by the Consumer Electronics Group of the Electronic Industries Association. This satellite, satellite/terrestrial, and terrestrial digital technology will open up new audio broadcasting opportunities both domestically and worldwide. It will significantly improve the current quality of amplitude-modulated/frequency-modulated (AM/FM) radio with a new digitally modulated radio signal and will introduce true compact-disc-quality (CD-quality) sound for the first time. Lewis is hosting the laboratory testing of seven proposed digital audio radio systems and modes. Two of the proposed systems operate in two modes each, making a total of nine systems being tested. The nine systems are divided into the following types of transmission: in-band on-channel (IBOC), in-band adjacent-channel (IBAC), and new bands. The laboratory testing was conducted by the Consumer Electronics Group of the Electronic Industries Association. Subjective assessments of the audio recordings for each of the nine systems was conducted by the Communications Research Center in Ottawa, Canada, under contract to the Electronic Industries Association. The Communications Research Center has the only CCIR-qualified (Consultative Committee for International Radio) audio testing facility in North America. The main goals of the U.S. testing process are to (1) provide technical data to the Federal Communication Commission (FCC) so that it can establish a standard for digital audio receivers and transmitters and (2) provide the receiver and transmitter industries with the proper standards upon which to build their equipment. In addition, the data will be forwarded to the International Telecommunications Union to help in the establishment of international standards for digital audio receivers and transmitters, thus allowing U.S. manufacturers to compete in the

  5. Design of Transmitter for CDM Based 2×2 Multiple Input Multiple Output Channel Sounder for Multipath Delay Measurement

    Directory of Open Access Journals (Sweden)

    M. H. Ullah

    2012-01-01

    Full Text Available Problem statement: Multiple Input Multiple Output (MIMO wireless communication system is an innovative solution to improve the bandwidth efficiency by exploiting multipath-richness of the propagation environment. The degree of multipath-richness of the channel will determine the capacity gain attainable by MIMO deployment. Approach: Therefore, it is very important to have accurate knowledge of the propagation environment/radio channel before MIMO implement. The radio channel behavior can be anticipated by channel measurement or channel sounding. Code Division Multiplexing (CDM is one of the channel sounding techniques that allow accurate measurement at the cost of hardware complexity. CDM based channel sounder, requires code with excellent auto-correlation and cross-correlation properties which generally difficult to be achieved simultaneously. Results: In this study, an efficient transmitter for CDM-based 2×2 MIMO channel sounding technique with Loosely Synchronous (LS codes is designed. Simulation results shows that the channel sounding scheme using LS codes gives very good performance for measuring 2×2 MIMO channel behavior. The BPSK transmitter is designed using MATLAB, Verilog and Xilinx system generator blocks. Conclusion: The whole design is simulated as a single ISE project by using ModelSim simulation tool and compiled using ISE 9.2. However the proposed design of transmitter using LS code of length 8190 bits can measure multipath delay of minimum 0.13 μs and maximum 520 μs.

  6. On hybrid cooperation in underlay cognitive radio networks

    KAUST Repository

    Mahmood, Nurul Huda

    2012-11-01

    In wireless systems where transmitters are subject to a strict received power constraint, such as in underlay cognitive radio networks, cooperative communication is a promising strategy to enhance network performance, as it helps to improve the coverage area and outage performance of a network. However, this comes at the expense of increased resource utilization. To balance the performance gain against the possible over-utilization of resources, we propose a hybrid-cooperation technique for underlay cognitive radio networks, where secondary users cooperate only when required. Various performance measures of the proposed hybrid-cooperation technique are analyzed in this paper, and are also further validated numerically. © 2012 IEEE.

  7. A COTS RF/Optical Software Defined Radio for the Integrated Radio and Optical Communications Test Bed

    Science.gov (United States)

    Nappier, Jennifer M.; Zeleznikar, Daniel J.; Wroblewski, Adam C.; Tokars, Roger P.; Schoenholz, Bryan L.; Lantz, Nicholas C.

    2017-01-01

    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administration (NASA) is investigating the merits of a hybrid radio frequency (RF) and optical communication system for deep space missions. In an effort to demonstrate the feasibility and advantages of a hybrid RF/Optical software defined radio (SDR), a laboratory prototype was assembled from primarily commercial-off-the-shelf (COTS) hardware components. This COTS platform has been used to demonstrate simultaneous transmission of the radio and optical communications waveforms through to the physical layer (telescope and antenna). This paper details the hardware and software used in the platform and various measures of its performance. A laboratory optical receiver platform has also been assembled in order to demonstrate hybrid free space links in combination with the transmitter.

  8. Clean relaying aided cognitive radio under the coexistence constraint

    CERN Document Server

    Lin, Pin-Hsun; Su, Hsuan-Jung; Hong, Y -W Peter

    2011-01-01

    We consider the interference-mitigation based cognitive radio where the primary and secondary users can coexist at the same time and frequency bands, under the constraint that the rate of the primary user (PU) must remain the same with a single-user decoder. To meet such a coexistence constraint, the relaying from the secondary user (SU) can help the PU's transmission under the interference from the SU. However, the relayed signal in the known dirty paper coding (DPC) based scheme is interfered by the SU's signal, and is not "clean". In this paper, under the half-duplex constraints, we propose two new transmission schemes aided by the clean relaying from the SU's transmitter and receiver without interference from the SU. We name them as the clean transmitter relaying (CT) and clean transmitter-receiver relaying (CTR) aided cognitive radio, respectively. The rate and multiplexing gain performances of CT and CTR in fading channels with various availabilities of the channel state information at the transmitters ...

  9. Base Level Management of Radio Frequency Radiation Protection Program

    Science.gov (United States)

    1989-04-01

    with a healti h....:d. V. STANDARDS A. The Basis of Our Permissible Exposure Limits (PELs). 1. What level of RFR is safe? It’s a big question, and a lot...mobile lifting equipment, hand-held radios, climbing gear, etc. b. Check out your equipment. Is the calibration current? Does the probe frequency range...CH--Hazardous levels possible, but only in areas that require climbing . GH--Ground-level hazardous exposures possible. DL--Transmitter dummy loaded. SH

  10. How does a little acronym become a big transmitter?

    Science.gov (United States)

    Krnjević, Kresimir

    2004-10-15

    After an overview of the early, chequered history of the discovery of GABA and its gradual acceptance as inhibitory synaptic transmitter in the brain, the article lists and discusses some of the more unexpected later developments in studies of GABA, especially its role as excitatory transmitter in the immature brain.

  11. 47 CFR 95.667 - CB transmitter power.

    Science.gov (United States)

    2010-10-01

    ... transmitter power. The dissipation rating of all the semiconductors or electron tubes which supply RF power to the antenna terminals of each CB transmitter must not exceed 10 W. For semiconductors, the dissipation... semiconductor. These values may be temperature de-rated by no more than 50 °C. For an electron tube,...

  12. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huidong; Tian, Chuan; Lu, Jun; Myjak, Mitchell J.; Martinez, Jayson J.; Brown, Richard S.; Deng, Zhiqun Daniel

    2016-09-20

    This paper presents a self-powered underwater acoustic transmitter using a piezoelectric beam to harvest the mechanical energy from fish swimming. This transmitter does not require a battery and is demonstrated in live fish. It transmits an acoustic waveform as the implanted fish swims. It enables long-term monitoring of aquatic animals.

  13. 47 CFR 80.209 - Transmitter frequency tolerances.

    Science.gov (United States)

    2010-10-01

    ... facsimile emissions 20 Hz. For narrow-band direct printing and data emissions 10 Hz. 2 For digital selective... emissions 20 Hz. For transmitters with narrow-band direct printing and data emissions 10 Hz 2 For transmitters with digital selective calling emissions 10 Hz. For all other emissions 100. (ii) Ship...

  14. 47 CFR 22.507 - Number of transmitters per station.

    Science.gov (United States)

    2010-10-01

    ..., stand-alone transmitter is linked to the system via a control/repeater facility or by satellite... 47 Telecommunication 2 2010-10-01 2010-10-01 false Number of transmitters per station. 22.507 Section 22.507 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

  15. 43 CFR 4.702 - Transmittal of appeal file.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Transmittal of appeal file. 4.702 Section... PROCEDURES Special Rules Applicable to Other Appeals and Hearings § 4.702 Transmittal of appeal file. Within... decision is being appealed shall transmit to the Office of the Director the entire official file in...

  16. All-optical orthogonal frequency division multiplexing (OFDM) transmitter

    DEFF Research Database (Denmark)

    2015-01-01

    The invention relates to an all-optical orthogonal frequency division multiplexing (OFDM) transmitter for generating an OFDM output signal. The transmitter comprises a first time-domain optical Fourier transform (OFT) assembly, the first OFT assembly is of a K-D-K configuration and comprises...

  17. Juvenile Salmon Acoustic Telemetry System Transmitter Downsize Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J.; Myjak, Mitchell J.

    2010-04-30

    At the request of the U.S. Army Corps of Engineers, Portland District, researchers from Pacific Northwest National Laboratory investigated the use of an application-specific integrated circuit (ASIC) to reduce the weight and volume of Juvenile Salmon Acoustic Telemetry System (JSATS) transmitters while retaining current functionality. Review of the design of current JSATS transmitters identified components that could be replaced by an ASIC while retaining the function of the current transmitter and offering opportunities to extend function if desired. ASIC design alternatives were identified that could meet transmitter weight and volume targets of 200 mg and 100 mm3. If alternatives to the cylindrical batteries used in current JSATS transmitters can be identified, it could be possible to implant ASIC-based JSATS transmitters by injection rather than surgery. Using criteria for the size of fish suitable for surgical implantation of current JSATS transmitters, it was concluded that fish as small as 70 mm in length could be implanted with an ASIC-based transmitter, particularly if implantation by injection became feasible.

  18. A CONTACTLESS TRANSMITTER FOR THE M TYPE DATA TRANSMISSION SYSTEM.

    Science.gov (United States)

    A contactless transmitter employing electromagnetic principles for the M type data transmission system is described. It could be contained in a size 11 standard housing if the six semiconductor main switches are mounted externally. Tests showed that the transmitter will operate satisfactorily at speeds in excess of 3000 rev/min, and that it could form the basis of a brushless dc motor . (Author)

  19. Radio frequency nonionizing radiation in a community exposed to radio and television broadcasting.

    Science.gov (United States)

    Burch, James B; Clark, Maggie; Yost, Michael G; Fitzpatrick, Cole T E; Bachand, Annette M; Ramaprasad, Jaya; Reif, John S

    2006-02-01

    Exposure to radio frequency (RF) nonionizing radiation from telecommunications is pervasive in modern society. Elevated disease risks have been observed in some populations exposed to radio and television transmissions, although findings are inconsistent. This study quantified RF exposures among 280 residents living near the broadcasting transmitters for Denver, Colorado. RF power densities outside and inside each residence were obtained, and a global positioning system (GPS) identified geographic coordinates and elevations. A view-shed model within a geographic information system (GIS) characterized the average distance and percentage of transmitters visible from each residence. Data were collected at the beginning and end of a 2.5-day period, and some measurements were repeated 8-29 months later. RF levels logged at 1-min intervals for 2.5 days varied considerably among some homes and were quite similar among others. The greatest differences appeared among homes within 1 km of the transmitters. Overall, there were no differences in mean residential RF levels compared over 2.5 days. However, after a 1- to 2-year follow-up, only 25% of exterior and 38% of interior RF measurements were unchanged. Increasing proximity, elevation, and line-of-sight visibility were each associated with elevated RF exposures. At average distances from > 1-3 km, exterior RF measurements were 13-30 times greater among homes that had > 50% of the transmitters visible compared with homes with < or = 50% visibility at those distances. This study demonstrated that both spatial and temporal factors contribute to residential RF exposure and that GPS/GIS technologies can improve RF exposure assessment and reduce exposure misclassification.

  20. Variable angle transmittance of silver grid transparent electrodes

    Science.gov (United States)

    Zhao, Yuan-Yuan; Zheng, Mei-Ling; Dong, Xian-Zi; Zhao, Zhen-Sheng; Duan, Xuan-Ming

    2016-10-01

    We focus on investigating the optical transmittance of silver grid transparent electrodes (SGTEs) in variable angle view theoretically and experimentally, rather than the optical transmittance under the normal incidence. The variable angle transmittance (VAT) values of SGTEs are measured on a home-made experimental setup. The experimental results about difference of the transmittance difference under different angles are small and negligible, although the measured angle is changed. Theoretically, the physical mechanism on nearly constant transmittance for different angle view can be well explained according to the theory of geometrical optics. This study provides an approach for investigating the VAT values of SGTEs in a controllable fashion and the influence of viewing angle of the touch screen.

  1. 47 CFR 90.473 - Operation of internal transmitter control systems through licensed fixed control points.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operation of internal transmitter control... Transmitter Control Internal Transmitter Control Systems § 90.473 Operation of internal transmitter control systems through licensed fixed control points. An internal transmitter control system may be...

  2. Electromagnetic Interference Assessment of CDMA and GSM Wireless Phones to Aircraft Navigation Radios

    Science.gov (United States)

    Ely, Jay J.; Nguyen, Truong X.; Koppen, Sandra V.; Salud, M. Theresa

    2002-01-01

    To address the concern for cellular phone electromagnetic interference (EMI) to aircraft radios, a radiated emission measurement process for CDMA (IS-95) and GSM (ETSI GSM 11.22) wireless handsets was developed. Spurious radiated emissions were efficiently characterized from devices tested in either a semi-anechoic or reverberation chamber, in terms of effective isotropic radiated power. Eight representative handsets (4 GSM, 4 CDMA) were commanded to operate while varying their radio transmitter parameters (power, modulation, etc.). This report provides a detailed description of the measurement process and resulting data, which may subsequently be used by others as a basis of consistent evaluation for cellular/PCS phones, Bluetooth, IEEE802.11b, IEEE802.11a, FRS/GMRS radios, and other portable transmitters. Aircraft interference path loss (IPL) and navigation radio interference threshold data from numerous reference documents, standards, and NASA partnerships were compiled. Using this data, a preliminary risk assessment is provided for CDMA and GSM wireless phone interference to aircraft localizer, Glideslope, VOR, and GPS radio receivers on typical transport airplanes. The report identifies where existing data for device emissions, IPL, and navigation radio interference thresholds needs to be extended for an accurate risk assessment for wireless transmitters in aircraft.

  3. Optimum Location and System Engineering of High Power, High Frequency Transmitter-Receiver in Combat Vehicles (Short Communication

    Directory of Open Access Journals (Sweden)

    S. Sathyamurthy

    2010-04-01

    Full Text Available This paper discusses the procedure adapted after carrying out several iterations for selecting an ideal location to introduce a high power high frequency (HF transmitter-receiver in a tactical combat vehicle from electromagnetic compatibility view. This radio set contributes for very high field strength to neighbouring electronic devices and other very high frequency (VHF Tx-Rx situated in the same vehicular platform. An integrated approach was followed in deciding the optimum solution to locate the HF radio set. Leakage from HF radio set is to be minimised within the vehicle to reduce the field coupling level to neighbouring equipment. Radiation from HF antenna was maximised by careful installation of antenna, outside the vehicle environment to ensure optimum radiation of intended signal. Voltage standing wave ratio (VSWR measurement was carried out to verify this. Four different locations experimented have been reported in this paper. The vehicle penetration loss (VPL can reveal the amount of leakage from external field generated by antennas to field inside the turret. The HF, being a congested operating spectrum, due care was taken in electromagnetic interference control of HF-VHF radios and other tank electronic subsystems. High RF power of HF transmitter and very high sensitivity of HF receiver could affect systems either way. Hence, electromagnetic compatibility (EMC measures and optimum location of HF radio set are important from MIL-STD461 C, MIL6051-D/MIL-STD464A point of view.Defence Science Journal, 2010, 60(3, pp.302-306, DOI:http://dx.doi.org/10.14429/dsj.60.357

  4. A simple mixture to enhance muscle transmittance

    Science.gov (United States)

    Oliveira, Luís; Lage, Armindo; Clemente, Manuel Pais; Tuchin, Valery V.

    2008-06-01

    Skeletal muscle is a fibrous tissue composed by muscle fibers and interstitial fluid. Due to this constitution, the muscle presents a non uniform refractive index profile that origins strong light scattering. One way to improve tissue transmittance is to reduce this refractive index mismatch by immersing the muscle in an optical clearing agent. As a consequence of such immersion tissue also suffers dehydration. The study of the optical clearing effect created by a simple mixture composed by ethanol, glycerol and distilled water has proven its effectiveness according to the variations observed in the parameters under study. The effect was characterized in terms of its magnitude, time duration and histological variations. The applied treatment has created a small reduction of the global sample refractive index that is justified by the long time rehydration caused by water in the immersing solution. From the reduction in sample pH we could also identify the dehydration process created in the sample. The immersion treatment has originated fiber bundle contraction and a spread distribution of the muscle fiber bundles inside. New studies with the mixture used, or with other combinations of its constituents might be interesting to perform with the objective to develop new clinical procedures.

  5. SW-100 FPSM Typical Fault Analysis of Broadcast Transmitter%SW-100FPSM广播发射机的典型故障探析

    Institute of Scientific and Technical Information of China (English)

    刘亮

    2014-01-01

    本文简要介绍了 PSM 短波广播发射机调制方式及工作原理,分析了 PSM 短波广播发射机优点。针SW-100FPSM广播发射机运行维护中出现的典型故障进行了分析研讨,提出了解决对策。%This paper briefly introduces the PSM shortwave broadcast transmitter modulation mode and working principle, analyses the PSM shortwave radio transmitter. It analyzed and put forward countermeasure for the typical fault in the main-tenance counter the SW-100FPSM shortwave broadcast transmitter.

  6. Piezoelectric transducer design for a miniaturized injectable acoustic transmitter

    Science.gov (United States)

    Li, H.; Jung, K. W.; Deng, Z. D.

    2015-11-01

    Implantable acoustic transmitters have been used in the last 20 years to track fish movement for fish survival and migration behavior studies. However, the relatively large weights and sizes of commercial transmitters limit the populations of studied fish. The surgical implantation procedures may also affect fish adversely and incur a significant amount of labor. Therefore, a smaller, lighter, and injectable transmitter was needed, and similar or better acoustic performance and service life over those provided by existing commercial transmitters was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. Our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the signal was not blocked by the transmitter body. We found that a novel off-center tube transducer improved the average source level by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 1.3 dB. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. Lastly, a tuning inductor in series with the transducer was used to help optimize the source level. The findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.

  7. Distance Dependent Model for the Delay Power Spectrum of In-room Radio Channels

    DEFF Research Database (Denmark)

    Steinböck, Gerhard; Pedersen, Troels; Fleury, Bernard Henri;

    2013-01-01

    A model based on experimental observations of the delay power spectrum in closed rooms is proposed. The model includes the distance between the transmitter and the receiver as a parameter which makes it suitable for range based radio localization. The experimental observations motivate the propos...

  8. Impact of cognitive radio on radio astronomy

    NARCIS (Netherlands)

    Bentum, M.J.; Boonstra, A.J.; Baan, W.A.

    2010-01-01

    The introduction of new communication techniques requires an increase in the efficiency of spectrum usage. Cognitive radio is one of the new techniques that fosters spectrum efficiency by using unoccupied frequency spectrum for communications. However, cognitive radio will increase the transmission

  9. Resonance and Radio

    Science.gov (United States)

    Starrett, Malin J.

    2008-01-01

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

  10. Combined operation of two ground transmitters for enhanced ionospheric heating

    Science.gov (United States)

    Lee, M. C.; Groves, K. M.; Liao, C. P.; Rivas, D. R.; Kuo, S. P.

    1988-01-01

    The combined operation of a high or medium frequency ground transmitter and a VLF transmitter for enhanced ionospheric heating is examined. The high or medium frequency transmitter operating in a pulsed mode produce short-scale density striations that can render the nonlinear mode conversion of the subsequently launched VLF waves into lower hybrid waves. Also if the VLF waves are intense enough, they can excite meter-scale density striations and lower hybrid waves via parametric instabilities. The expected ionospheric effects of the system are discussed.

  11. Thermal Design and Flight Validation for Solid-state Transmitter

    OpenAIRE

    Wang Lei; Wen Yao-pu

    2014-01-01

    Solid-state transmitter with large power and high heat flux is a key equipment of an HJ-1-C satellite; therefore, it has a great influence on satellite thermal design. Thermal design ensures that the solid-state transmitter works well within the allowable temperature limits of the equipment. The solid-state transmitter thermal design and solved key problems are provided in accordance with the HJ-1-C characteristics. Moreover, an analysis of satellites on orbit was performed. Based on the tele...

  12. Intelligent Industrial Transmitters of Pressure and Other Process Parameters

    Directory of Open Access Journals (Sweden)

    B. L. Miljković

    2009-11-01

    Full Text Available An overview is given of industrial measurement instruments (transmitters of pressure and other process parameters. It is followed by a description of the technology used in the current generation of intelligent transmitters featuring two-way digital communication. A recently developed product of IHTM–CMTM, the intelligent pressure transmitter is presented, including a description of the software temperature compensation method for the used pressure sensor. Features and application possibilities of the developed hardware and software platform are discussed, as well as its suitability for the realization of wireless sensors.

  13. Transmitter antenna placement in indoor environments using particle swarm optimisation

    Science.gov (United States)

    Talepour, Zeinab; Tavakoli, Saeed; Ahmadi-Shokouh, Javad

    2013-07-01

    The aim of this article is to suitably locate the minimum number of transmitter antennas in a given indoor environment to achieve good propagation coverage. To calculate the electromagnetic field in various points of the environment, we develop a software engine, named ray-tracing engine (RTE), in Matlab. To achieve realistic calculations, all parameters of geometry and material of building are considered. Particle swarm optimisation is employed to determine good location of transmitters. Simulation results show that a full coverage is obtained through suitably locating three transmitters.

  14. Photonic chip based transmitter optimization and receiver demultiplexing of a 1.28 Tbit/s OTDM signal

    DEFF Research Database (Denmark)

    Vo, T.D.; Hu, Hao; Galili, Michael;

    2010-01-01

    We demonstrate chip-based Tbaud optical signal processing for all-optical performance monitoring, switching and demultiplexing based on the instantaneous Kerr nonlinearity in a dispersion-engineered As_2S_3 planar waveguide. At the Tbaud transmitter, we use a THz bandwidth radio-frequency spectrum...... analyzer to perform all-optical performance monitoring and to optimize the optical time division multiplexing stages as well as mitigate impairments, for example, dispersion. At the Tbaud receiver, we demonstrate error-free demultiplexing of a 1.28 Tbit/s single wavelength, return-to-zero signal to 10 Gbit...

  15. Distributed Transmitter Localization by Power Difference of Arrival (PDOA) on a Network of GNU Radio Sensors

    Science.gov (United States)

    2015-02-03

    requiring the least hardware investment is to localize by received signal strength [1, 4, 5]. Because our intended scenario of low-complexity...MHz were taken with a spectrum analyzer program on the USRP and a range finder was used to measure the distance between the emitter and sensor

  16. A Potential Transmitter Architecture for Future Generation Green Wireless Base Station

    Directory of Open Access Journals (Sweden)

    Cijvat Ellie

    2009-01-01

    Full Text Available Abstract Current radio frequency power amplifiers in 3G base stations have very high power consumption leading to a hefty cost and negative environmental impact. In this paper, we propose a potential architecture design for future wireless base station. Issues associated with components of the architecture are investigated. The all-digital transmitter architecture uses a combination of envelope elimination and restoration (EER and pulse width modulation (PWM/pulse position modulation (PPM modulation. The performance of this architecture is predicted from the measured output power and efficiency curves of a GaN amplifier. 57% efficiency is obtained for an OFDM signal limited to 8 dB peak to average power ratio. The PWM/PPM drive signal is generated using the improved Cartesian sigma delta techniques. It is shown that an RF oversampling by a factor of four meets the WLAN spectral mask, and WCDMA specification is met by an RF oversampling of sixteen.

  17. A Potential Transmitter Architecture for Future Generation Green Wireless Base Station

    Directory of Open Access Journals (Sweden)

    Mike Faulkner

    2009-01-01

    Full Text Available Current radio frequency power amplifiers in 3G base stations have very high power consumption leading to a hefty cost and negative environmental impact. In this paper, we propose a potential architecture design for future wireless base station. Issues associated with components of the architecture are investigated. The all-digital transmitter architecture uses a combination of envelope elimination and restoration (EER and pulse width modulation (PWM/pulse position modulation (PPM modulation. The performance of this architecture is predicted from the measured output power and efficiency curves of a GaN amplifier. 57% efficiency is obtained for an OFDM signal limited to 8 dB peak to average power ratio. The PWM/PPM drive signal is generated using the improved Cartesian sigma delta techniques. It is shown that an RF oversampling by a factor of four meets the WLAN spectral mask, and WCDMA specification is met by an RF oversampling of sixteen.

  18. Phase-coded pulse aperiodic transmitter coding

    Directory of Open Access Journals (Sweden)

    I. I. Virtanen

    2009-07-01

    Full Text Available Both ionospheric and weather radar communities have already adopted the method of transmitting radar pulses in an aperiodic manner when measuring moderately overspread targets. Among the users of the ionospheric radars, this method is called Aperiodic Transmitter Coding (ATC, whereas the weather radar users have adopted the term Simultaneous Multiple Pulse-Repetition Frequency (SMPRF. When probing the ionosphere at the carrier frequencies of the EISCAT Incoherent Scatter Radar facilities, the range extent of the detectable target is typically of the order of one thousand kilometers – about seven milliseconds – whereas the characteristic correlation time of the scattered signal varies from a few milliseconds in the D-region to only tens of microseconds in the F-region. If one is interested in estimating the scattering autocorrelation function (ACF at time lags shorter than the F-region correlation time, the D-region must be considered as a moderately overspread target, whereas the F-region is a severely overspread one. Given the technical restrictions of the radar hardware, a combination of ATC and phase-coded long pulses is advantageous for this kind of target. We evaluate such an experiment under infinitely low signal-to-noise ratio (SNR conditions using lag profile inversion. In addition, a qualitative evaluation under high-SNR conditions is performed by analysing simulated data. The results show that an acceptable estimation accuracy and a very good lag resolution in the D-region can be achieved with a pulse length long enough for simultaneous E- and F-region measurements with a reasonable lag extent. The new experiment design is tested with the EISCAT Tromsø VHF (224 MHz radar. An example of a full D/E/F-region ACF from the test run is shown at the end of the paper.

  19. Educational Radio in India

    OpenAIRE

    VYAS, R. V.; R. C. Sharma; Kumar, Ashwini

    2002-01-01

    There are a good number of research studies, which indicate that radio has been a good medium of education delivery. Many experiments have been conducted in different countries on the use of radio in education. Radio has been used in conventional education, non-formal education, for agricultural education, for community development, in distance education, so on and so forth. This paper explains various educational radio projects undertaken in India

  20. Design of CMOS RFIC ultra-wideband impulse transmitters and receivers

    CERN Document Server

    Nguyen, Cam

    2017-01-01

    This book presents the design of ultra-wideband (UWB) impulse-based transmitter and receiver frontends, operating within the 3.1-10.6 GHz frequency band, using CMOS radio-frequency integrated-circuits (RFICs). CMOS RFICs are small, cheap, low power devices, better suited for direct integration with digital ICs as compared to those using III-V compound semiconductor devices. CMOS RFICs are thus very attractive for RF systems and, in fact, the principal choice for commercial wireless markets.  The book comprises seven chapters. The first chapter gives an introduction to UWB technology and outlines its suitability for high resolution sensing and high-rate, short-range ad-hoc networking and communications. The second chapter provides the basics of CMOS RFICs needed for the design of the UWB RFIC transmitter and receiver presented in this book. It includes the design fundamentals, lumped and distributed elements for RFIC, layout, post-layout simulation, and measurement. The third chapter discusses the basics of U...

  1. Long-Term Energy Constraints and Power Control in Cognitive Radio Networks

    CERN Document Server

    Mériaux, François; Lasaulce, Samson; Garnaev, Andrey

    2011-01-01

    When a long-term energy constraint is imposed to a transmitter, the average energy-efficiency of a transmitter is, in general, not maximized by always transmitting. In a cognitive radio context, this means that a secondary link can re-exploit the non-used time-slots. In the case where the secondary link is imposed to generate no interference on the primary link, a relevant issue is therefore to know the fraction of time-slots available to the secondary transmitter, depending on the system parameters. On the other hand, if the secondary transmitter is modeled as a selfish and free player choosing its power control policy to maximize its average energy-efficiency, resulting primary and secondary signals are not necessarily orthogonal and studying the corresponding Stackelberg game is relevant to know the outcome of this interactive situation in terms of power control policies.

  2. Commercial Radio as Communication.

    Science.gov (United States)

    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. Streaming Transmitter over Block-Fading Channels with Delay Constraint

    CERN Document Server

    Cocco, Giuseppe; Ibars, Christian

    2012-01-01

    Data streaming transmission, in which the data arrives at the transmitter gradually over time is studied. It is assumed that the transmitter receives a new message at each channel block at a constant rate which is fixed by an underlying application, and tries to broadcast these messages to users within a certain deadline. The channels are assumed to be block fading and independent over blocks and users. The performance measure is the average total rate of received information at the users within the transmission deadline. Three different encoding schemes are proposed and compared with an informed transmitter upper bound in terms of the average total rate for a set of users with varying channel qualities. Analytical upper bounds on the average total rate are derived for all the proposed schemes. It is shown that no single transmission strategy dominates the others at all channel settings, and the best transmitter streaming scheme depends on the distribution of the average channel conditions over the users.

  4. High Temperature Telemetry Transmitter for Venus Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed S-band telemetry transmitter will operate in the exterior Venusian corrosive, high pressure, 460oC ambient atmosphere without being contained in a...

  5. High Temperature Telemetry Transmitter for Venus Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed S-band telemetry transmitter will operate in the exterior Venusian high pressure, 465?aC ambient atmosphere without being contained in a thermally...

  6. Efficient and Compact Semiconductor Laser Transmitter Modules Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Continue development of a Compact Transmitter Module (CTM). Modules will be voltage controlled to adjust wavlength using temperature and drive current settings. The...

  7. Television Transmitter Locations, Published in Not Provided, US Army.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Television Transmitter Locations dataset as of Not Provided. Data by this publisher are often provided in Not Applicable coordinate system; in a Not Applicable...

  8. Compressed Sensing Based Fingerprint Identification for Wireless Transmitters

    Directory of Open Access Journals (Sweden)

    Caidan Zhao

    2014-01-01

    Full Text Available Most of the existing fingerprint identification techniques are unable to distinguish different wireless transmitters, whose emitted signals are highly attenuated, long-distance propagating, and of strong similarity to their transient waveforms. Therefore, this paper proposes a new method to identify different wireless transmitters based on compressed sensing. A data acquisition system is designed to capture the wireless transmitter signals. Complex analytical wavelet transform is used to obtain the envelope of the transient signal, and the corresponding features are extracted by using the compressed sensing theory. Feature selection utilizing minimum redundancy maximum relevance (mRMR is employed to obtain the optimal feature subsets for identification. The results show that the proposed method is more efficient for the identification of wireless transmitters with similar transient waveforms.

  9. High-power solid-state microwave transmitter

    Science.gov (United States)

    Boreham, J. D.; Conroy, B. L.; Postal, R. B.; Yenche, D. G.

    1981-01-01

    Transmitter phases outputs from individual amplifier modules then combines them in multielement array feed antenna. Size and power capability of system are variable for radar and small-angle scanning applications.

  10. 47 CFR 95.855 - Transmitter effective radiated power limitation.

    Science.gov (United States)

    2010-10-01

    ... Transmitter effective radiated power limitation. The effective radiated power (ERP) of each CTS and RTU shall... with an ERP exceeding 20 watts. No mobile RTU may transmit with an ERP exceeding 4 watts....

  11. Reflectance and transmittance model for recto-verso halftone prints

    OpenAIRE

    Hebert, M.; R. D. Hersch

    2006-01-01

    We propose a spectral prediction model for predicting the reflectance and transmittance of recto-verso halftone prints. A recto-verso halftone print is modeled as a diffusing substrate surrounded by two inked interfaces in contact with air (or with another medium). The interaction of light with the print comprises three components: (a) the attenuation of the incident light penetrating the print across the inked interface, (b) the internal reflectance and internal transmittance that accounts f...

  12. Photonic integrated transmitter and receiver for NG-PON2

    Science.gov (United States)

    Tavares, Ana; Lopes, Ana; Rodrigues, Cláudio; Mãocheia, Paulo; Mendes, Tiago; Brandão, Simão.; Rodrigues, Francisco; Ferreira, Ricardo; Teixeira, António

    2014-08-01

    In this paper the authors present a monolithic Photonic Integrated Circuit which includes a transmitter and a receiver for NG-PON2. With this layout it is possible to build an OLT and, by redesigning some filters, also an ONU. This technology allows reducing the losses in the transmitter and in the receiver, increasing power budget, and also reducing the OEO conversions, which has been a major problem that operators want to surpass.

  13. Modeling and compensation of transmitter nonlinearity in coherent optical OFDM.

    Science.gov (United States)

    Amiralizadeh, Siamak; Nguyen, An T; Rusch, Leslie A

    2015-10-05

    We present a comprehensive study of nonlinear distortions from an optical OFDM transmitter. Nonlinearities are introduced by the combination of effects from the digital-to-analog converter (DAC), electrical power amplifier (PA) and optical modulator in the presence of high peak-to-average power ratio (PAPR). We introduce parameters to quantify the transmitter nonlinearity. High input backoff avoids OFDM signal compression from the PA, but incurs high penalties in power efficiency. At low input backoff, common PAPR reduction techniques are not effective in suppressing the PA nonlinear distortion. A bit error distribution investigation shows a technique combining nonlinear predistortion with PAPR mitigation could achieve good power efficiency by allowing low input backoff. We use training symbols to extract the transmitter nonlinear function. We show that piecewise linear interpolation (PLI) leads to an accurate transmitter nonlinearity characterization. We derive a semi-analytical solution for bit error rate (BER) that validates the PLI approximation accurately captures transmitter nonlinearity. The inverse of the PLI estimate of the nonlinear function is used as a predistorter to suppress transmitter nonlinearity. We investigate performance of the proposed scheme by Monte Carlo simulations. Our simulations show that when DAC resolution is more than 4 bits, BER below forward error correction limit of 3.8 × 10(-3) can be achieved by using predistortion with very low input power backoff for electrical PA and optical modulator.

  14. UV transmittance during the crosslinking procedure: tunable treatment

    Science.gov (United States)

    Lincoln, Victor A. C.; Mello, Marcio M.; Ventura, Liliane

    2014-02-01

    The transmittance of UVA light through the in vitro human cornea over the thickness of 400um during the corneal collagen cross-linking procedure has been measured using an optical fiber (600 μm core diameter) fixed just before the cornea and attached to Spectrophotometer. The 10 corneas, (average of 6 days post-mortem) were washed with saline and cross-linked with the currently used protocol. To enhance absorption of UV radiation, Riboflavin solution (0.1% and 400 mOsm) was applied prior to and during exposure. The UVA beam - 365nm +/- 5nm at 3mW/cm2 +/- 0.003mW/cm2 - was focused directly onto the corneal stroma. The measured average transmittance of the cornea without Riboflavin was 64.1%. Preceding the irradiation but after 6 applications of Riboflavin at 5min intervals (total of 30min) transmittance decreased to 21.1%. The 30min of irradiation were then accompanied by an additional 6 applications of Riboflavin at 5min intervals (for a total of treatment time of 1h), resulting in a further decrease in transmittance to 12.2%, which is in agreement with current literature. The average transmittance in terms of energy during the 30 minutes irradiation procedure fluctuated from 0.63 to 0.37 mW/cm2. These results indicate different levels of UV transmittance during treatment, leading to consider a new personalized treatment with tunable UV power irradiation.

  15. Ultraviolet absorption and epidermal-transmittance spectra in foliage

    Energy Technology Data Exchange (ETDEWEB)

    Day, T.A.; Howells, B.W.; Rice, W.J. (Dept. of Biology, West Virginia Univ., Morgantown, WV (United States))

    1994-01-01

    We examined the UV absorption spectra and the epidermal-transmittance spectra (280-350 nm) of foliage from 42 plant species. Sun foliage was sampled from naturally growing individuals of seven species in each of six life forms comprising two evergreen groups (gymnosperms and angiosperms) and four deciduous angiosperm groups (trees, shrubs and vines, herbaceous dicotyledons and grasses). There were large differences in absorption spectra of whole-leaf extracts among species. While absorbance declined with increasing wavelength in most woody species, there was a through in absorbance around 300 nm in many herbaceous species. Absorption spectra were negatively correlated with epidermal-transmittance spectra in 31 of the 42 species. Relationships between absorbance and transmittance did not follow the theoretical exponential function. Species rankings of UV-screening effectiveness were similar when we assessed it by using epidermal transmittance at single wavelengths (300 or 320 nm) or different UV-action spectra to weight epidermal-transmittance spectra and estimate the levels of biologically effective UV reaching the mesophyll. Thus, differences in absolute epidermal transmittance among species appeared to overshadow spectral differences. Nevertheless, the differences we found in the internal UV spectral regime in foliage suggest that whole-plant action spectra will differ among species. While species rankings of UV-screening effectiveness were similar when different action spectra were used, the absolute amounts of biologically effective UV reaching the mesophyll of species varied considerably when different action spectra were used. (au) (46 refs.)

  16. The perceived transmittance of inhomogeneous surfaces and media.

    Science.gov (United States)

    Anderson, Barton L; Singh, Manish; Meng, Jeanette

    2006-06-01

    A series of experiments was performed to determine how the visual system computes the transmittance of inhomogeneous surfaces and media. Previous work (Anderson, B. L. (1999) Stereoscopic surface perception. Neuron, 26, 919-928; Anderson, B. L. (2003) The role of occlusion in the perception of depth, lightness, and opacity. Psychological Review, 110, 762-784) has suggested that the visual system employs a transmittance anchoring principle in determining when transparency is perceived. This principle states that the visual system interprets the highest contrast region along contours and surfaces as a region in plain view and uses this anchor as a reference point for transparency computations. In particular, recent work has shown that the transmittance of homogeneous transparent surfaces is well described by a ratio of contrasts model (Singh, M., & Anderson, B. L. (2002). Toward a perceptual theory of transparency. Psychological Review, 109, 492-519). In this model, the transmittance of a transparent surface is determined by the contrast of a transparent image region normalized by the contrast of the region in plain view. Here, a series of experiments is reported that assesses this model for inhomogeneous transparent surfaces that vary in both space and time. The results of these experiments reveal that transmittance anchoring has both a spatial and temporal component, and that the perceived transmittance of transparent surfaces is well described by a ratio of perceived contrasts model.

  17. Radio-transparent multi-layer insulation for radiowave receiver

    CERN Document Server

    Choi, J; Mima, S; Oguri, S; Takahashi, K; Tajima, O

    2013-01-01

    In the field of radiowave detection, enhancement of the amount of detected light is essential for greater scientific achievements. A large aperture system is a promising way to increase the number of photons that are received at the detectors. One challenge in the application of radio transmittable apertures is keeping the detectors cool. This is because transparency to thermal radiation above the radio frequency range increases the thermal load. For shielding from thermal radiation, the general strategy involves installation of thermal filters in the light path between the aperture and the detectors. However, enlargement of the aperture gives rise to a new difficulty: warming of the filter. A thermal radiation shielding technology that does not warm the associated filter while allowing enlargement of the aperture is long-awaited. We propose radio-transparent multi-layer insulation (RT-MLI), which comprises a set of stacked insulator layers that are transparent in the radiowave frequency range. The basic idea...

  18. Location-based resource allocation for OFDMA cognitive radio systems

    KAUST Repository

    Nam, Haewoon

    2010-01-01

    In cognitive radio systems, in order for the secondary users to opportunistically share the spectrum without interfering the primary users, an accurate spectrum measurement and a precise estimation of the interference at the primary users are necessary but are challenging tasks. Since it is impractical in cognitive radio systems to assume that the channel state information of the interference link is available at the cognitive transmitter, the interference at the primary users is hard to be estimated accurately. This paper introduces a resource allocation algorithm for OFDMA-based cognitive radio systems, which utilizes location information of the primary and secondary users instead of the channel state information of the interference link. Simulation results show that it is indeed effective to incorporate location information into resource allocation so that a near-optimal capacity is achieved.

  19. Wave Optics Based LEO-LEO Radio Occultation Retrieval

    DEFF Research Database (Denmark)

    von Benzon, Hans-Henrik; Høeg, Per

    2016-01-01

    in the signal amplitude caused by atmospheric absorption. The radio wave transmitter is placed on one of these satellites while the receiver is placed on the other LEO satellite. One of the drawbacks of normal GPS based radio occultations is that external information is needed to calculate some...... of the atmospheric products such as the correct water vapor content in the atmosphere. These limitations can be overcome when a proper selected range of high frequency waves are used to probe the atmosphere. Probing frequencies close to the absorption line of water vapor have been included, thus allowing...... chain is therefore a wave optics based retrieval chain and it is therefore possible to process measurements that include multipath. In this paper simulated LEO to LEO radio occultations based on 5 different frequencies are used. The 5 frequencies are placed in the XK or KM frequency band. This new wave...

  20. Radiography of Spanish Radio

    Directory of Open Access Journals (Sweden)

    Dra. Emma Rodero Antón

    2007-01-01

    Full Text Available In its eighty years of existence, radio has been always characterized to adapt to the social, cultural and technological transformations. Thus it has been until this moment. Nevertheless, some years ago, the authors and professionals of this medium have been detecting a stagnation that affects to its structure. At a time in continuous technological evolution, radio demands a deep transformation. For that reason, from the conviction of which the future radio, public and commercial, will necessarily have to renew itself, in this paper we establish ten problems and their possible solutions to the radio crisis in order to draw an x-ray of radio in Spain. Radio has future, but it is necessary to work actively by it. That the radio continues being part of sound of our life, it will depend on the work of all: companies, advertisers, professionals, students, investigators and listeners.

  1. Power-Efficient Ultra-Wideband Waveform Design Considering Radio Channel Effects

    Directory of Open Access Journals (Sweden)

    Yipeng Liu

    2011-04-01

    Full Text Available This paper presents a power-efficient maskconstrained ultra-wideband (UWB waveform design with radio channel effects taken into consideration. Based on a finite impulse response (FIR filter, we develop a convex optimization model with respect to the autocorrelation of the filter coefficients to optimize the transmitted signal power spectrum, subject to a regulatory emission mask. To improve power efficiency, effects of transmitter radio frequency (RF components are included in the optimization of the transmitter-output waveform, and radio propagation effects are considered for obtaining the most efficient waveform at the receiver. Optimum coefficients of the FIR filter are obtained through spectral factorization of their autocorrelations. Simulation results show that the proposed method is able to maximize the transmitted UWB signal power under mask constraints set by regulatory authorities, while mitigating the power loss caused by channel attenuations.

  2. Analisis Kendala Perizinan Spektrum Frekuensi Radio untuk Radio Komunitas

    OpenAIRE

    Sri Wahyuningsih

    2014-01-01

    Izin penggunaan spektrum frekuensi radio diatur dalam Undang-undang No.36 tahun 1999 tentang Telekomunikasi. Saat ini masih ditemukan Radio Komunitas yang belum memiliki Izin Stasiun Radio (ISR). Penelitian ini bertujuan untuk menemu kenali kendala-kendala yang dihadapi Radio Komunitas pada proses pengajuan Izin Stasiun Radio (ISR). Teknik pengumpulan data melalui wawancara dengan penanggungjawab Radio Komunitas dan pejabat di lingkungan Balai Monitor Frekuensi Radio (Balmon) di Jakarta, Sema...

  3. Analisis Kendala Perizinan Spektrum Frekuensi Radio untuk Radio Komunitas

    OpenAIRE

    2014-01-01

    Izin penggunaan spektrum frekuensi radio diatur dalam Undang-undang No.36 tahun 1999 tentang Telekomunikasi. Saat ini masih ditemukan Radio Komunitas yang belum memiliki Izin Stasiun Radio (ISR). Penelitian ini bertujuan untuk menemu kenali kendala-kendala yang dihadapi Radio Komunitas pada proses pengajuan Izin Stasiun Radio (ISR). Teknik pengumpulan data melalui wawancara dengan penanggungjawab Radio Komunitas dan pejabat di lingkungan Balai Monitor Frekuensi Radio (Balmon) di Jakarta, Sema...

  4. 47 CFR 22.573 - Use of base transmitters as repeaters.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Use of base transmitters as repeaters. 22.573... of base transmitters as repeaters. As an additional function, base transmitters may be used as repeaters. Licensees must be able to turn the base transmitter on or off from the control point...

  5. 47 CFR 90.475 - Operation of internal transmitter control systems in specially equipped systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operation of internal transmitter control... Control Internal Transmitter Control Systems § 90.475 Operation of internal transmitter control systems in specially equipped systems. (a) An internal transmitter control system need not be designed to meet...

  6. Senior radio listeners

    DEFF Research Database (Denmark)

    Blaakilde, Anne Leonora

    Radiobroadcasting and the hardware materialization of radio have during the 20th century changed significantly, which means that senior radio listeners have travelled along with this evolution from large, impressive radio furnitures to DAB and small, wireless, mobile devices, and from grave...... and solemn radio voices to lightharted, laughing and chatting speakers. Senior radio listerners have experienced the development and refinements of technique, content and genres. It is now expected of all media users that they are capable of crossing media, combining, juggling and jumping between various...... media platforms, not the least when listening to radio. The elder generation is no exception from this. Recently, for instance, the Danish public broadcast DR has carried out an exodus of programmes targeted for the senior segment. These programmes are removed from regular FM and sent to DAB receivers...

  7. Fast Radio Bursts

    Indian Academy of Sciences (India)

    Akshaya Rane; Duncan Lorimer

    2017-09-01

    We summarize our current state of knowledge of fast radio bursts (FRBs) which were first discovered a decade ago. Following an introduction to radio transients in general, including pulsars and rotating radio transients, we discuss the discovery of FRBs. We then discuss FRB follow-up observations in the context of repeat bursts before moving on to review propagation effects on FRB signals, FRB progenitor models and an outlook on FRBs as potential cosmological tools.

  8. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals

    Science.gov (United States)

    Li, Huidong; Tian, Chuan; Lu, Jun; Myjak, Mitchell J.; Martinez, Jayson J.; Brown, Richard S.; Deng, Zhiqun Daniel

    2016-09-01

    Acoustic telemetry is the primary method to actively track aquatic animals for behavioral studies. However, the small storage capacities of the batteries used in the transmitters limit the time that the implanted animals can be studied. In this research, we developed and implemented a battery-free acoustic transmitter that uses a flexible piezoelectric beam to harvest energy from fish swimming as the power source. The transmitter sends out a unique identification code with a sufficiently strong signal (150 dB, ref: 1 μPa at 1 meter) that has a detection range of up to 100 meters. Two prototypes, 100 mm and 77 mm long, respectively, weighing only about 1 gram or less in air, were sub-dermally implanted in two species of live fish. Transmissions were successfully detected as the fish swam in a natural manner. This represents the first known implanted energy-harvesting transmitter demonstrated in vivo. Successful development of this transmitter greatly expands the potential for long-term studies of the behaviors of aquatic animals and for subsequently developing strategies to mitigate the environmental impacts of renewable energy systems.

  9. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals

    Science.gov (United States)

    Li, Huidong; Tian, Chuan; Lu, Jun; Myjak, Mitchell J.; Martinez, Jayson J.; Brown, Richard S.; Deng, Zhiqun Daniel

    2016-01-01

    Acoustic telemetry is the primary method to actively track aquatic animals for behavioral studies. However, the small storage capacities of the batteries used in the transmitters limit the time that the implanted animals can be studied. In this research, we developed and implemented a battery-free acoustic transmitter that uses a flexible piezoelectric beam to harvest energy from fish swimming as the power source. The transmitter sends out a unique identification code with a sufficiently strong signal (150 dB, ref: 1 μPa at 1 meter) that has a detection range of up to 100 meters. Two prototypes, 100 mm and 77 mm long, respectively, weighing only about 1 gram or less in air, were sub-dermally implanted in two species of live fish. Transmissions were successfully detected as the fish swam in a natural manner. This represents the first known implanted energy-harvesting transmitter demonstrated in vivo. Successful development of this transmitter greatly expands the potential for long-term studies of the behaviors of aquatic animals and for subsequently developing strategies to mitigate the environmental impacts of renewable energy systems. PMID:27647426

  10. A Zynq-based Cluster Cognitive Radio

    OpenAIRE

    Rooks, Kurtis M.

    2014-01-01

    Traditional hardware radios provide very rigid solutions to radio problems. Intelligent software defined radios, also known as cognitive radios, provide flexibility and agility compared to hardware radio systems. Cognitive radios are well suited for radio applications in a changing radio frequency environment, such as dynamic spectrum access. In this thesis, a cognitive radio is demonstrated where the system self reconfigures to dem...

  11. Transformations of Radio Aesthetics

    Directory of Open Access Journals (Sweden)

    Grażyna Stachyra

    2015-09-01

    Full Text Available The paper presents some remarks upon the nature of contemporary radio communications in the context of the terms “aesthetics” and “aesthetisation”. The latter, denoting a process of turning aesthetic phenomena into unaesthetic ones, becomes the dominant strategy of formatted radio. The “surface aesthetisation,” which provides mainly pleasure and entertainment, transcends the simple styling of objects or environment and appears to be a more significant strand of contemporary culture. The article shows several examples of “surface” modelling of radio programming and explains their purpose in radio communication.

  12. STEM on the radio

    Science.gov (United States)

    Showstack, Randy

    2011-10-01

    Looking for an Internet radio station focusing on programing about science, technology, engineering, and math (STEM)? The U.S. National Science Foundation (NSF) announced on 26 September the launch of Science360 Radio, which it says is the first Internet radio stream dedicated to STEM programing. Science360 includes more than 100 radio shows and podcasts that are available on the Web as well as on iPhone and Android devices. The shows originate from a variety of sources, including NSF, other U.S. government agencies, science organizations, universities, and media outlets. For more information, see http://science360.gov/files/.

  13. Advanced sensing techniques for cognitive radio

    CERN Document Server

    Zhao, Guodong; Li, Shaoqian

    2017-01-01

    This SpringerBrief investigates advanced sensing techniques to detect and estimate the primary receiver for cognitive radio systems. Along with a comprehensive overview of existing spectrum sensing techniques, this brief focuses on the design of new signal processing techniques, including the region-based sensing, jamming-based probing, and relay-based probing. The proposed sensing techniques aim to detect the nearby primary receiver and estimate the cross-channel gain between the cognitive transmitter and primary receiver. The performance of the proposed algorithms is evaluated by simulations in terms of several performance parameters, including detection probability, interference probability, and estimation error. The results show that the proposed sensing techniques can effectively sense the primary receiver and improve the cognitive transmission throughput. Researchers and postgraduate students in electrical engineering will find this an exceptional resource.

  14. Mean field games for cognitive radio networks

    KAUST Repository

    Tembine, Hamidou

    2012-06-01

    In this paper we study mobility effect and power saving in cognitive radio networks using mean field games. We consider two types of users: primary and secondary users. When active, each secondary transmitter-receiver uses carrier sensing and is subject to long-term energy constraint. We formulate the interaction between primary user and large number of secondary users as an hierarchical mean field game. In contrast to the classical large-scale approaches based on stochastic geometry, percolation theory and large random matrices, the proposed mean field framework allows one to describe the evolution of the density distribution and the associated performance metrics using coupled partial differential equations. We provide explicit formulas and algorithmic power management for both primary and secondary users. A complete characterization of the optimal distribution of energy and probability of success is given.

  15. Complete affordable system for simultaneous VIS/NIR and MWIR/LWIR spectral atmospheric transmittance measurements (ATMS)

    Science.gov (United States)

    Cabib, Dario; Gil, Amir; Biran, Oren

    2010-04-01

    During the second half of the '70's Ben-Shalom et al.1 developed a system for research of the spectral transmittance of the atmosphere in the infrared range on nearly horizontal atmospheric paths between 2.5 and 14 microns. The system configuration is bi-static: a source (of known emission) and a measuring sensor station linked by line of sight. Comparison of the measured radiation with the known emission gives the fraction of transmitted radiation. The longest path published there was a respectable 44 Km. and provided significant data. However, the system required a very high temperature (2400K) short lived (~3 hours) emitter element, home-built projection optics, and a cumbersome closed cycle water cooling system for the 6 KWatt source. The sensor end of the system was a Circular Variable Filter (CVF) based spectroradiometer using liquid nitrogen (LN2) cooled detectors. The signal processing electronics was based on a synchronous detection method using a chopper at the source and a radio-transmitted reference signal in phase with the chopper. In this paper we describe the Atmospheric Transmittance Measurement System (ATMS) recently built by CI and presently undergoing reliability and accuracy tests. Its main advantages over the old system are: it is built of only commercial off-the-shelf items (COTS), it can measure in both the IR and visible ranges simultaneously, it is cost effective and easy to use and maintain. The calibration method and transmittance measurement algorithm are also described. A transmittance measurement of a nearly horizontal sea level path of 6.5 Km. is shown here as an example for the whole spectral range of 0.4 to 14 microns in less than very clear and dry weather conditions. The result shows agreement with the MODTRAN model on the spectral behavior but at the time of publication we are still investigating the accuracy of the actual transmittance values. We believe that the ATMS can be used for longer paths, based on the signal to noise

  16. Robust Beamforming in Interference Channels with Imperfect Transmitter Channel Information

    CERN Document Server

    Mochaourab, Rami

    2011-01-01

    We consider $K$ links operating concurrently in the same spectral band. Each transmitter has multiple antennas, while each receiver uses a single antenna. This setting corresponds to the multiple-input single-output interference channel. We assume perfect channel state information at the receivers whereas the transmitters only have estimates of the true channels. The channel estimation errors are assumed to be bounded in elliptical regions whose geometry is known at the transmitters. Robust beamforming optimizes worst-case received power gains, and a Pareto optimal point is a worst-case achievable rate tuple from which it is impossible to increase a link's performance without degrading the performance of another. We characterize the robust beamforming vectors necessary to operate at any Pareto optimal point. Moreover, these beamforming vectors are parameterized by $K(K-1)$ real-valued parameters. We analyze the system's spectral efficiency at high and low signal-to-noise ratio (SNR). Zero forcing transmission...

  17. Joint Transmitter-Receiver Optimization in the Downlink CDMA Systems

    Directory of Open Access Journals (Sweden)

    Mohammad Saquib

    2002-08-01

    Full Text Available To maximize the downlink code-division multiple access (CDMA system capacity, we propose to minimize the total transmitted power of the system subject to users′ signal-to-interference ratio (SIR requirements via designing optimum transmitter sequences and utilizing linear optimum receivers (minimum mean square error (MMSE receiver. In our work on joint transmitter-receiver design for the downlink CDMA systems with multiple antennas and multipath channels, we develop several optimization algorithms by considering various system constraints and prove their convergence. We empirically observed that under the optimization algorithm with no constraint on the system, the optimum receiver structure matches the received transmitter sequences. A simulation study is performed to see how the different practical system constraints penalize the system with respect to the optimum algorithm with no constraint on the system.

  18. Experimental Realization of Tunable Metamaterial Hyper-transmitter

    Science.gov (United States)

    Yoo, Young Joon; Yi, Changhyun; Hwang, Ji Sub; Kim, Young Ju; Park, Sang Yoon; Kim, Ki Won; Rhee, Joo Yull; Lee, YoungPak

    2016-01-01

    We realized the tunable metamaterial hyper-transmitter in the microwave range utilizing simple planar meta-structure. The single-layer metamaterial hyper-transmitter shows that the transmission peak occurs at 14 GHz. In case of the dual-layer one, it is possible to control the transmission peak from 5 to 10 GHz. Moreover, all the transmission peaks reveal transmission over 100%. We experimentally and theoretically investigated these phenomena through 3-dimensional simulation and measurement. The reason for being over 100% is also elucidated. The suggested hyper-transmitter can be used, for example, in enhancing the operating distance of the electromagnetic wave in Wi-Fi, military radar, wireless power transfer and self-driving car. PMID:27629804

  19. Experimental Realization of Tunable Metamaterial Hyper-transmitter

    Science.gov (United States)

    Yoo, Young Joon; Yi, Changhyun; Hwang, Ji Sub; Kim, Young Ju; Park, Sang Yoon; Kim, Ki Won; Rhee, Joo Yull; Lee, Youngpak

    2016-09-01

    We realized the tunable metamaterial hyper-transmitter in the microwave range utilizing simple planar meta-structure. The single-layer metamaterial hyper-transmitter shows that the transmission peak occurs at 14 GHz. In case of the dual-layer one, it is possible to control the transmission peak from 5 to 10 GHz. Moreover, all the transmission peaks reveal transmission over 100%. We experimentally and theoretically investigated these phenomena through 3-dimensional simulation and measurement. The reason for being over 100% is also elucidated. The suggested hyper-transmitter can be used, for example, in enhancing the operating distance of the electromagnetic wave in Wi-Fi, military radar, wireless power transfer and self-driving car.

  20. Enhancing GNU Radio for Hardware Accelerated Radio Design

    OpenAIRE

    Irick, Charles Robert

    2010-01-01

    As technology evolves and new methods for designing radios arise, it becomes necessary to continue the search for fast and flexible development environments. Some of these new technologies include software defined radio (SDR), Field Programmable Gate Arrays (FPGAs), and the open source project GNU Radio. Software defined radio is a concept that GNU Radio has harnessed to allow developers to quickly create flexible radio designs. In terms of hardware, the maturity of FPGAs give ...

  1. Examination of an optical transmittance test for photovoltaic encapsulation materials

    Science.gov (United States)

    Miller, David C.; Bengoechea, Jaione; Bokria, Jayesh G.; Köhl, Michael; Powell, Nick E.; Smith, Michael E.; White, Michael D.; Wilson, Helen Rose; Wohlgemuth, John H.

    2013-09-01

    The optical transmittance of encapsulation materials is a key characteristic for their use in photovoltaic (PV) modules. Changes in transmittance with time in the field affect module performance, which may impact product warranties. Transmittance is important in product development, module manufacturing, and field power production (both immediate and long-term). Therefore, an international standard (IEC 62788-1-4) has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the optical performance of PV encapsulation materials. Existing standards, such as ASTM E903, are general and more appropriately applied to concentrated solar power than to PV. Starting from the optical transmittance measurement, the solar-weighted transmittance of photon irradiance, yellowness index (which may be used in aging studies to assess durability), and ultraviolet (UV) cut-off wavelength may all be determined using the proposed standard. The details of the proposed test are described. The results of a round-robin experiment (for five materials) conducted at seven laboratories to validate the test procedure using representative materials are also presented. For example, the Encapsulation Group actively explored the measurement requirements (wavelength range and resolution), the requirements for the spectrophotometer (including the integrating sphere and instrument accessories, such as a depolarizer), specimen requirements (choice of glass-superstrate and -substrate), and data analysis (relative to the light that may be used in the PV application). The round-robin experiment identified both intra- and inter-laboratory instrument precision and bias for five encapsulation materials (encompassing a range of transmittance and haze-formation characteristics).

  2. Examination of an optical transmittance test for photovoltaic encapsulation materials

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C.; Bengoechea, Jaione; Bokria, Jayesh G.; Köhl, Michael; Powell, Nick E.; Smith, Michael E.; White, Michael D.; Wilson, Helen Rose; Wohlgemuth, John H.; Dhere, Neelkanth G.; Wohlgemuth, John H.; Lynn, Kevin W.

    2013-09-24

    The optical transmittance of encapsulation materials is a key characteristic for their use in photovoltaic (PV) modules. Changes in transmittance with time in the field affect module performance, which may impact product warranties. Transmittance is important in product development, module manufacturing, and field power production (both immediate and long-term). Therefore, an international standard (IEC 62788-1-4) has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the optical performance of PV encapsulation materials. Existing standards, such as ASTM E903, are general and more appropriately applied to concentrated solar power than to PV. Starting from the optical transmittance measurement, the solar-weighted transmittance of photon irradiance, yellowness index (which may be used in aging studies to assess durability), and ultraviolet (UV) cut-off wavelength may all be determined using the proposed standard. The details of the proposed test are described. The results of a round-robin experiment (for five materials) conducted at seven laboratories to validate the test procedure using representative materials are also presented. For example, the Encapsulation Group actively explored the measurement requirements (wavelength range and resolution), the requirements for the spectrophotometer (including the integrating sphere and instrument accessories, such as a depolarizer), specimen requirements (choice of glass-superstrate and -substrate), and data analysis (relative to the light that may be used in the PV application). The round-robin experiment identified both intra- and inter-laboratory instrument precision and bias for five encapsulation materials (encompassing a range of transmittance and haze-formation characteristics).

  3. Transmittance jump in a thin aluminium layer during laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Bykovsky, N E; Senatsky, Yu V [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Pershin, S M; Samokhin, A A [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2016-02-28

    A jump in the transmittance (from ∼0.1% to ∼50% for ∼1 ns) of an optical gate on a Mylar film (a thin aluminium layer on a Lavsan substrate) irradiated by nanosecond (10{sup -7} – 10{sup -8} s) pulses of a neodymium laser with an intensity up to 0.1 GW cm{sup -2} has been recorded. The mechanism of a fast (10{sup -10} – 10{sup -11} s) increase in the transmittance of the aluminium layer upon its overheating (without boiling) to the metal – insulator phase-transition temperature is discussed. (interaction of laser radiation with matter. laser plasma)

  4. On the Capacity of Interference Channels with One Cooperating Transmitter

    CERN Document Server

    Maric, I; Krämer, G; Shamai, S

    2007-01-01

    Inner and outer bounds are established on the capacity region of two-sender, two-receiver interference channels where one transmitter knows both messages. The transmitter with extra knowledge is referred to as being cognitive. The inner bound is based on strategies that generalize prior work, and include rate-splitting, Gel'fand-Pinsker coding and cooperative transmission. A general outer bound is based on the Nair-El Gamal outer bound for broadcast channels. A simpler bound is presented for the case in which one of the decoders can decode both messages. The bounds are evaluated and compared for Gaussian channels.

  5. Transmittance characteristics of plasmonic graphene ribbons with a wing

    Science.gov (United States)

    Yuan, Lin; Yan, Xin; Wang, Yueke; Sang, Tian; Yang, Guofeng

    2016-09-01

    We numerically investigate the transmittance characteristics of graphene ribbons with a wing by the finite element method. By determining the dispersion relation of edge graphene plasmon (EGP) modes and analyzing the mode distributions, it is considered that the transmission dips originate from the resonances of three EGP modes, namely, the symmetrical EGPs, antisymmetrical EGPs, and EGPs of a semi-infinite sheet. By changing the width and length of the wing, it was further confirmed that transmission dips originate from the EGP modes. Owing to the tunable permittivity of graphene by adjusting the gate voltage, the transmittance dips can be easily tuned.

  6. Transmittance characteristics and tunable sensor performances of plasmonic graphene ribbons

    Science.gov (United States)

    Yan, Xin; Yuan, Lin; Wang, Yueke; Sang, Tian; Yang, Guofeng

    2016-08-01

    We investigate the transmittance characteristics of graphene ribbons numerically. It is found that the transmission dips originate from the transverse and longitudinal resonances of edge graphene plasmon modes, supported by the graphene ribbon resonator. The environmental refractive index changes are detected by measuring the resulting spectral shifts of the resonant transmission dip, so the graphene ribbons can be applied to plasmonic sensor in infrared. Simulation results show that sensing performances for each resonant mode are similar, and figure of merit can be up to 6. Beside, thanks to the tunable permittivity of graphene by bias voltages, the transmittance spectra and sensor performances can be easily tuned.

  7. Analisis Kendala Perizinan Spektrum Frekuensi Radio untuk Radio Komunitas

    Directory of Open Access Journals (Sweden)

    Sri Wahyuningsih

    2014-03-01

    Full Text Available Izin penggunaan spektrum frekuensi radio diatur dalam Undang-undang No.36 tahun 1999 tentang Telekomunikasi. Saat ini masih ditemukan Radio Komunitas yang belum memiliki Izin Stasiun Radio (ISR. Penelitian ini bertujuan untuk menemu kenali kendala-kendala yang dihadapi Radio Komunitas pada proses pengajuan Izin Stasiun Radio (ISR. Teknik pengumpulan data melalui wawancara dengan penanggungjawab Radio Komunitas dan pejabat di lingkungan Balai Monitor Frekuensi Radio (Balmon di Jakarta, Semarang dan Yogyakarta. Analisis data mengacu pada model Matthew B Miles dan A Michael Huberman. Hasil penelitian menyatakan kendala yang dihadapi terutama pada sertifikasi perangkat Radio Komunitas.

  8. New Information About The Behavior Of Lontra Longicaudis (Carnivora: Mustelidae By Radio-Telemetry

    Directory of Open Access Journals (Sweden)

    Nakano-Oliveira E.

    2004-07-01

    Full Text Available Eduardo Nakano-Oliveira, Roberto Fusco, Etiene A. V. Dos Santos, Emygdio L. A. CDuring the development of a study about a community of carnivorous mammals, an otter was captured and equiped with a radio transmitter in an area of mangrove in the south coast of the State of São Paulo, southeast of Brazil. This study verified that: 1 - the animal used at least three burrows without communication between them. 2 – the most used burrow was at a distance of 2,6 km from the capture place; 3 - this individual usually moved between two islands that were separated by an estuary whose medium width was of approximately 1 km; 4 – it spent a long period on a small island of approximately 0,06 Km2 where a muddy substratum prevailed, not allowing the construction of a burrow. In spite of the little time that the otter stayed with the radio-transmitter, the data obtained are of relevant importance as they show an unknown activity pattern, besides showing in a short period some patterns of burrow use. Even though the otter removed its radio-collar, it didn’t cause any damage to the individual and it allowed the registration of behaviour patterns that had not been described before. Based upon the radio-transmitter as adapted, new perspectives open up for the effective study of this species, increasing the possibilities of obtaining data about activity patterns and home range for Lontra longicaudis.

  9. Effects of laser frequency chirp on modal noise in short-range radio over multimode fiber links

    DEFF Research Database (Denmark)

    Visani, Davide; Tartarini, Giovanni; Petersen, Martin Nordal;

    2010-01-01

    An important effect of the frequency chirp of the optical transmitter in radio over multimode fiber links is put into evidence experimentally and modeled theoretically for the first time, to our knowledge. This effect can have an important impact in short-range connections, where, although...

  10. Antenna array characterisation and signal processing for an FM radio-based passive coherent location radar system

    NARCIS (Netherlands)

    Belfiori, F.; Monni, S.; Rossum, W.L. van; Hoogeboom, P.

    2012-01-01

    The design of passive coherent location radar, which exploits broadcasting transmitters of opportunity in the very high frequency (VHF) radio bandwidth, is presented. Here, the authors primarily focus on the system set-up and on the digital pre-processing steps. Emphasis is given to the antenna sect

  11. Radio Graceful Hamming Graphs

    Directory of Open Access Journals (Sweden)

    Niedzialomski Amanda

    2016-11-01

    Full Text Available For k ∈ ℤ+ and G a simple, connected graph, a k-radio labeling f : V (G → ℤ+ of G requires all pairs of distinct vertices u and v to satisfy |f(u − f(v| ≥ k + 1 − d(u, v. We consider k-radio labelings of G when k = diam(G. In this setting, f is injective; if f is also surjective onto {1, 2, . . . , |V (G|}, then f is a consecutive radio labeling. Graphs that can be labeled with such a labeling are called radio graceful. In this paper, we give two results on the existence of radio graceful Hamming graphs. The main result shows that the Cartesian product of t copies of a complete graph is radio graceful for certain t. Graphs of this form provide infinitely many examples of radio graceful graphs of arbitrary diameter. We also show that these graphs are not radio graceful for large t.

  12. Radio Emission from Exoplanets

    OpenAIRE

    George, Samuel J.; Stevens, Ian R.

    2008-01-01

    We present results from new low frequency observations of two extrasolar planetary systems (Epsilon Eridani and HD128311) taken at 150 MHz with the Giant Metrewave Radio Telescope (GMRT). We do not detect either system, but are able to place tight upper limits on their low frequency radio emission.

  13. Valuing commercial radio licences

    NARCIS (Netherlands)

    Kerste, M.; Poort, J.; van Eijk, N.

    2015-01-01

    Within the EU regulatory framework, licensees for commercial radio broadcasting may be charged a fee to ensure optimal allocation of scarce resources but not to maximize public revenues. While radio licence renewal occurs in many EU countries, an objective, model-based approach for setting licence f

  14. DF100 kW PSM Transmitter Audio Path Analysis%DF100 kW PSM发射机音频通路分析

    Institute of Scientific and Technical Information of China (English)

    刘毅

    2015-01-01

    DF100 kW PSM transmitter as an important model of Press and Publication Administration of Radio, the radio station plays an irreplaceable role in the country’s short-covering task, while maintaining the audio path is one of the means to ensure that the transmitter normal broadcast. Actual work situation, analyzed and summarized DF100 kW PSM transmitter audio path and typical fault in order to provide a reference for future maintenance staff.%DF100 kW PSM发射机作为国家新闻出版广电总局无线局的重要机型,在全国的短波覆盖任务中起着不可替代的作用,而音频通路的维护是保证发射机正常播音的手段之一。结合实际工作情况,分析总结了DF100 kW PSM发射机的音频通路和典型故障,以期为维护人员日后的工作提供一定的参考。

  15. Design and Simulation of GaussianFSK Transmitter in UHF Band Using Direct Modulation of ΣΔ Modulator Fractional-N Synthesizer

    Directory of Open Access Journals (Sweden)

    Ali Mohammed Noori Hasan

    2008-01-01

    Full Text Available This research involves design and simulation of GaussianFSK transmitter in UHF band using direct modulation of ΣΔ fractional-N synthesizer with the following specifications: Frequency range (869.9– 900.4 MHz, data rate 150kbps, channel spacing (500 kHz, Switching time 1 µs, & phase noise @10 kHz = -85dBc.New circuit techniques have been sought to allow increased integration of radio transmitters and receivers, along with new radio architectures that take advantage of such techniques. Characteristics such as low power operation, small size, and low cost have become the dominant design criteria by which these systems are judged.A direct modulation by ΣΔ fractional-N synthesizer is proposed in this research, because this approach provides the required characteristics such as low power. The Σ∆ modulator placed on digital phase-locked loop to control the fractional value of the frequency division ratio thereby eliminating spurious and allowing good phase noise performance. The modulation type of Gaussian FSK is used to obtain high spectral efficiency of modulated waveform.The applications of this transmitter in low cost wireless data transfer, security systems, RF remote controls and wireless metering.

  16. Kafedra radiotekhnichnykh prystroiv ta system [Department of radio engineering devices and systems

    Directory of Open Access Journals (Sweden)

    V. P. Taranenko

    1998-09-01

    Full Text Available The department was founded in 1945 after the division of the department receiving and transmitting devices into two: radio receivers and radio transmitters in accordance with the direction and content of research the educational process changed its name to the radio engineering devices and systems. first department was headed by a famous scientist, corresponding member of the Academy of Sciences, Professor Semen Isaakovich Tetelbaum. After his death in 1958 the department was headed by his disciple, Professor Vadim Pavlovich Taranenko. Department is leading the preparation of bachelors and masters in "radio". It provides training in such subjects as radio devices, radio systems, computers, programming, and computer graphics, signal generation devices, computer-aided design in electronics, radio, Radiocomponents and fundamentals of microelectronics, electronic and quantum devices microwave, television basics, devices and systems TV and others. the Department scientific-methodical commission of the Ministry of Education of Ukraine towards the "radio", headed by the dean of the radio department prof. Pravda V.I.

  17. Cognitive Radio Transmission Strategies for Primary Erasure Channels

    CERN Document Server

    El-Samadony, Ahmed; Sultan, Ahmed

    2010-01-01

    A fundamental problem in cognitive radio systems is that the cognitive radio is ignorant of the primary channel state and the interference it inflicts on the primary license holder. In this paper we assume that the primary transmitter sends packets across an erasure channel and the primary receiver employs ACK/NAK feedback (ARQ) to retransmit erased packets. The cognitive radio can eavesdrop on the primary's ARQs. Assuming the primary channel states follow a Markov chain, this feedback gives the cognitive radio an indication of the primary link quality. Based on the ACK/NACK received, we devise optimal transmission strategies for the cognitive radio so as to maximize a weighted sum of primary and secondary throughput. The actual weight used during network operation is determined by the degree of protection afforded to the primary link. We study a two-state model where we characterize a scheme that spans the boundary of the primary-secondary rate region. Moreover, we study a three-state model where we derive t...

  18. Efficient and Compact Semiconductor Laser Transmitter Modules Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a Compact Transmitter Module (CTM) capable of operating at 1.26 5m, 1.57 5m and at 2 5m complete with all drive and control electronics for the TEC and the...

  19. 22 CFR 181.7 - Transmittal to the Congress.

    Science.gov (United States)

    2010-04-01

    ... Assistant Legal Adviser for Treaty Affairs to the Senate Committee on Foreign Affairs. ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Transmittal to the Congress. 181.7 Section 181.7 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL AGREEMENTS COORDINATION, REPORTING AND...

  20. Mark 4A DSN receiver-exciter and transmitter subsystems

    Science.gov (United States)

    Wick, M. R.

    1986-01-01

    The present configuration of the Mark 4A DSN Receiver-Exciter and Transmitter Subsystems is described. Functional requirements and key characteristics are given to show the differences in the capabilities required by the Networks Consolidation task for combined High Earth Orbiter and Deep Space Network tracking support.

  1. Airborne Measurements of Atmospheric Methane Using Pulsed Laser Transmitters

    Science.gov (United States)

    Numata, Kenji; Riris, Haris; Wu, Stewart; Gonzalez, Brayler; Rodriguez, Michael; Hasselbrack, William; Fahey, Molly; Yu, Anthony; Stephen, Mark; Mao, Jianping; Kawa, Stephan

    2016-01-01

    Atmospheric methane (CH4) is the second most important anthropogenic greenhouse gas with approximately 25 times the radiative forcing of carbon dioxide (CO2) per molecule. At NASA Goddard Space Flight Center (GSFC) we have been developing a laser-based technology needed to remotely measure CH4 from orbit. We report on our development effort for the methane lidar, especially on our laser transmitters and recent airborne demonstration. Our lidar transmitter is based on an optical parametric process to generate near infrared laser radiation at 1651 nanometers, coincident with a CH4 absorption. In an airborne flight campaign in the fall of 2015, we tested two kinds of laser transmitters --- an optical parametric amplifier (OPA) and an optical parametric oscillator (OPO). The output wavelength of the lasers was rapidly tuned over the CH4 absorption by tuning the seed laser to sample the CH4 absorption line at several wavelengths. This approach uses the same Integrated Path Differential Absorption (IPDA) technique we have used for our CO2 lidar for ASCENDS. The two laser transmitters were successfully operated in the NASAs DC-8 aircraft, measuring methane from 3 to 13 kilometers with high precision.

  2. Improved transmittance measurement with a magnesium oxide coated integrating sphere

    Science.gov (United States)

    Bowman, R. L.; Spisz, E. W.

    1972-01-01

    Simple and convenient technique has been found for extending transmittance measurement capability of conventional magnesium oxide coated integrating sphere system at low (near ultraviolet) wavelengths. Technique can be used to determine effect of contaminants on window materials and can also be used for measurements on thermal control coatings and telescope mirrors.

  3. Surgical insertion of transmitters and telemetry methods in fisheries research

    DEFF Research Database (Denmark)

    Rub, A. Michelle Wargo; Jepsen, Niels; Liedtke, Theresa L.

    2014-01-01

    implantation procedures for fish. We also intend to provide insight into the unique challenges of field-based aquatic surgical studies. Within this context, 4 aspects of the process for surgical implantation of transmitters in fish (ie, handling, aseptic technique, anesthesia, and implantation...

  4. Spectral transmittance of the spectacle scale of snakes and geckos

    NARCIS (Netherlands)

    Doorn, van K.; Sivak, J.G.

    2015-01-01

    The spectral transmittance of the optical media of the eye plays a substantial role in tuning the spectrum of light available for capture by the retina. Certain squamate reptiles, including snakes and most geckos, shield their eyes beneath a layer of transparent, cornified skin called the ‘spectacle

  5. Simulation on the Final Stage of 44 MHz Transmitter

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The 44 MHz transmitter will be used to power the 1:1 scale 100 MeV metal proctortype cavity. To improve the stability of the final stage amplifier and to obtain more output power, it is necessary to

  6. Controlled crumpling of graphene oxide films for tunable optical transmittance.

    Science.gov (United States)

    Thomas, Abhay V; Andow, Brandon C; Suresh, Shravan; Eksik, Osman; Yin, Jie; Dyson, Anna H; Koratkar, Nikhil

    2015-06-01

    The delamination buckling approach provides a facile means to dynamically control the optical transmittance of extremely flexible and stretchable graphene oxide coatings with fast response time. Such graphene oxide coatings can be deposited by scalable solution-processing methods for potential applications in dynamic glazing.

  7. High Speed Surface Thermocouples Interface to Wireless Transmitters

    Science.gov (United States)

    2017-03-15

    Transmitters David Patti 1 Item 6: Eric Gingrich, MS-12 1 RD ECOM-TARDEC-RTI-GVPM Russell Robinson, ACO 1 Item 14, Recipient Destinations: Include completed DD...David Patti: david.m.patti4.civ@mail.mil - Russell Robinson, ACO: russell.robinson@dcma.mil - OTIC (mai l 2 hardcopies) : Defense Technical Information

  8. Cavity-Beam-Transmitter Interaction Formula Collection with Derivation

    CERN Document Server

    Tückmantel, J

    2010-01-01

    The fundamental beam-cavity-transmitter relations for accelerating and deflecting/crab cavities are presented for steady state and time-varying situations. For completeness a compact proof of the Panofsky-Wenzel theorem is given and the fundamental beam loading theorem is derived.Also the determination of relative bunch form factors is shown.

  9. Surgical insertion of transmitters and telemetry methods in fisheries research

    DEFF Research Database (Denmark)

    Rub, A. Michelle Wargo; Jepsen, Niels; Liedtke, Theresa L.

    2014-01-01

    ) will be described. Effects of surgical insertion of transmitters (ie, tagging) and aspects of the surgical implantation process where collaboration and professional exchanges among nonveterinarian researchers and veterinarians may be most fruitful will be discussed. Although this report focuses on surgical...

  10. Intraperitoneal implantation of life-long telemetry transmitters in otariids.

    Science.gov (United States)

    Horning, Markus; Haulena, Martin; Tuomi, Pamela A; Mellish, Jo-Ann E

    2008-12-10

    Pinnipeds, including many endangered and declining species, are inaccessible and difficult to monitor for extended periods using externally attached telemetry devices that are shed during the annual molt. Archival satellite transmitters were implanted intraperitoneally into four rehabilitated California sea lions (Zalophus californianus) and 15 wild juvenile Steller sea lions (Eumetopias jubatus) to determine the viability of this surgical technique for the deployment of long-term telemetry devices in otariids. The life history transmitters record information throughout the life of the host and transmit data to orbiting satellites after extrusion following death of the host. Surgeries were performed under isoflurane anesthesia and single (n = 4) or dual (n = 15) transmitters were inserted into the ventrocaudal abdominal cavity via an 8.5 to 12 cm incision along the ventral midline between the umbilicus and pubic symphysis or preputial opening. Surgeries lasted 90 minutes (SD = 8) for the 19 sea lions. All animals recovered well and were released into the wild after extended monitoring periods from 27 to 69 days at two captive animal facilities. Minimum post-implant survival was determined via post-release tracking using externally attached satellite transmitters or via opportunistic re-sighting for mean durations of 73.7 days (SE = 9.0, Z. californianus) and 223.6 days (SE = 71.5, E. jubatus). The low morbidity and zero mortality encountered during captive observation and post-release tracking periods confirm the viability of this surgical technique for the implantation of long-term telemetry devices in otariids.

  11. Coordination procedure for radio relay and communication satellite services

    Science.gov (United States)

    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.

  12. Radio source evolution

    CERN Document Server

    Perucho, Manel

    2015-01-01

    Baldwin (1982) wrote that "the distribution of sources in the radio luminosity, P, overall physical size, D, diagram" could be considered as "the radio astronomer's H-R diagram". However, unlike the case of stars, not only the intrinsic properties of the jets, but also those of the host galaxy and the intergalactic medium are relevant to explain the evolutionary tracks of radio radio sources. In this contribution I review the current status of our understanding of the evolution of radio sources from a theoretical and numerical perspective, using the P-D diagram as a framework. An excess of compact (linear size < 10 kpc) sources could be explained by low-power jets being decelerated within the host galaxy, as shown by recent numerical simulations. These decelerated jets could also explain the population of the radio sources that have been recently classified as FR0. I will discuss the possible tracks that radio sources may follow within this diagram, and some of the physical processes that can explain the d...

  13. Radio broadcasting via satellite

    Science.gov (United States)

    Helm, Neil R.; Pritchard, Wilbur L.

    1990-10-01

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

  14. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary.......Internet radio is one of the growth areas of the Internet but, as this article will show, is fraught with difficulties and frustration for both the modestly-funded broadcaster (bitcaster) and the listener. The article will illustrate some of these problems by means of a short case study...

  15. Shoestring Budget Radio Astronomy

    Science.gov (United States)

    Hoot, John E.

    2017-06-01

    The commercial exploitation of microwave frequencies for cellular, WiFi, Bluetooth, HDTV, and satellite digital media transmission has brought down the cost of the components required to build an effective radio telescope to the point where, for the cost of a good eyepiece, you can construct and operate a radio telescope. This paper sets forth a family of designs for 1421 MHz telescopes. It also proposes a method by which operators of such instruments can aggregate and archive data via the Internet. With 90 or so instruments it will be possible to survey the entire radio sky for transients with a 24 hour cadence.

  16. Unlocking radio broadcasts

    DEFF Research Database (Denmark)

    Lykke, Marianne; Skov, Mette

    2012-01-01

    This poster reports the preliminary results of a user study uncovering the information seeking behaviour of humanities scholars dedicated to radio research. The study is part of an interdisciplinary research project on radio culture and auditory resources. The purpose of the study is to inform...... the design of information architecture and interaction design of a research infrastructure that will enable future radio and audio based research. Results from a questionnaire survey on humanities scholars’ research interest and information needs, preferred access points, and indexing levels are reported...

  17. Ionosphere and Radio Communication

    Indian Academy of Sciences (India)

    Saradi Bora

    2017-02-01

    The Earth's ionosphere consists of plasma produced by thephotoionization of thin upper atmospheric gases by UV raysand photons of short wavelength from the sun. The upperionosphere is used for radio communication and navigationas it reflects long, medium, as well as short radio waves. Sincesolar radiation is the main cause of the existence of ionosphere,any variation in the radiations can affect the entireradio communication system. This article attempts to brieflyintroduce the readers to the study of ionosphere in the contextof its use as a radio reflector, with particular reference toIndia.

  18. Radio y elecciones

    Directory of Open Access Journals (Sweden)

    Alma Rosa Alva de la Selva

    2000-01-01

    Full Text Available En este trabajo se analiza el comportamiento de la radio en México ante la contienda electoral de julio de 2000. Se examina el papel de la radio como espacio para la discusión política, así como el tratamiento informativo que hizo del tema. Asimismo, se analiza la posible repercusión de factores de reciente surgimiento en el panorama radiofónico para un manejo más autónomo de la información política en la radio

  19. Unlocking radio broadcasts

    DEFF Research Database (Denmark)

    Skov, Mette; Lykke, Marianne

    2012-01-01

    This poster reports the preliminary results of a user study uncovering the information seeking behaviour of humanities scholars dedicated to radio research. The study is part of an interdisciplinary research project on radio culture and auditory resources. The purpose of the study is to inform...... the design of information architecture and interaction design of a research infrastructure that will enable future radio and audio based research. Results from a questionnaire survey on humanities scholars‟ research interest and information needs, preferred access points, and indexing levels are reported...

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

    Science.gov (United States)

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

    2005-01-01

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

  1. Investigation of over-horizon VHF radio signals associated with earthquakes

    Directory of Open Access Journals (Sweden)

    Y. Fukumoto

    2001-01-01

    Full Text Available This paper presents the preliminary results on the possible reception of over-horizon VHF radio signals from a FM (frequency modulation transmitter during abnormal situations (probably in close association with earthquakes. The transmitter is FM Sendai (frequency = 77.1 MHz and the receiving station is our university (UEC at Chofu, Tokyo, with the transmitter-receiver distance being about 310 km. We first show a typical example of the reception of over-horizon VHF signals in which we present the amplitude behavior, azimuthal and incident angle estimation, etc. Then, we study the correlation between a signal anomaly and an earthquake and it seems that the over-horizon VHF signals observed are probably associated with earthquakes, observed about 7 to 0 days before an earthquake. The direction finding measurements have indicated that such signals are due to favorable tropospheric (but not ionospheric conditions attributed to the effects of earthquakes.

  2. Adaptive Sensing and Transmission Durations for Cognitive Radios

    CERN Document Server

    Afifi, Wessam; Nafie, Mohammed

    2010-01-01

    In a cognitive radio setting, secondary users opportunistically access the spectrum allocated to primary users. Finding the optimal sensing and transmission durations for the secondary users becomes crucial in order to maximize the secondary throughput while protecting the primary users from interference and service disruption. In this paper an adaptive sensing and transmission scheme for cognitive radios is proposed. We consider a channel allocated to a primary user which operates in an unslotted manner switching activity at random times. A secondary transmitter adapts its sensing and transmission durations according to its belief regarding the primary user state of activity. The objective is to maximize a secondary utility function. This function has a penalty term for collisions with primary transmission. It accounts for the reliability-throughput tradeoff by explicitly incorporating the impact of sensing duration on secondary throughput and primary activity detection reliability. It also accounts for thro...

  3. The digital sport radio.

    Directory of Open Access Journals (Sweden)

    Hilario José ROMERO BEJARANO

    2014-07-01

    Full Text Available Radio has been immersed in recent years in a phase of technological integration and business of multimedia, as well as diversification of systems and channels for broadcasting. In addition, Internet has been consolidated as the platform of digital radio that more has evolved as a result of its continued expansion. However, the merger radio-Internet must be understood as a new form of communication, and not solely as a new complementary medium. In this context, it is of great interest to analyze that transformations in the way of reception, contents, languages, programs and schedules, has brought with it for the radio that integration. To this end is taken as main reference the sports areas, a key aspect and broadly representative of the current broadcasting landscape.

  4. Music, Radio, and Mediatization

    DEFF Research Database (Denmark)

    Krogh, Mads; Michelsen, Morten

    2016-01-01

    Mediatization has become a key concept for understanding the relations between media and other cultural and social fields. Contributing to the discussions related to the concept of mediatization, this article discusses how practices of radio and music(al life) influence each other. We follow Deacon......’s and Stanyer’s advice to supplement the concept of mediatization with ‘a series of additional concepts at lower levels of abstraction’ and suggest, in this respect, the notion of heterogeneous milieus of music– radio. Hereby, we turn away from the all-encompassing perspectives related to the concept...... of mediatization where media as such seem to be ascribed agency. Instead, we consider historical accounts of music–radio in order to address the complex non- linearity of concrete processes of mediatization as they take place in the multiple meetings between a decentred notion of radio and musical life....

  5. Unveiling the radio cosmos

    Science.gov (United States)

    Vanderlinde, Keith

    2017-02-01

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

  6. Everyday Radio Telescope

    CERN Document Server

    Mandal, Pranshu; Kumar, Pratik; Yelikar, Anjali; Soni, Kanchan; T, Vineeth Krishna

    2016-01-01

    We have developed an affordable, portable college level radio telescope for amateur radio astronomy which can be used to provide hands-on experience with the fundamentals of a radio telescope and an insight into the realm of radio astronomy. With our set-up one can measure brightness temperature and flux of the Sun at 11.2 GHz and calculate the beam width of the antenna. The set-up uses commercially available satellite television receiving system and parabolic dish antenna. We report the detection of point sources like Saturn and extended sources like the galactic arm of the Milky way. We have also developed python pipeline, which are available for free download, for data acquisition and visualization.

  7. Division x: Radio Astronomy

    Science.gov (United States)

    Taylor, Russ; Chapman, Jessica; Rendong, Nan; Carilli, Christopher; Giovannini, Gabriele; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin; Lazio, Joseph; Morganti, Raffaella; Rubio, Monica; Shastri, Prajval

    2012-04-01

    This triennium has seen a phenomenal investment in development of observational radio astronomy facilities in all parts of the globe at a scale that significantly impacts the international community. This includes both major enhancements such as the transition from the VLA to the EVLA in North America, and the development of new facilities such as LOFAR, ALMA, FAST, and Square Kilometre Array precursor telescopes in Australia and South Africa. These developments are driven by advances in radio-frequency, digital and information technologies that tremendously enhance the capabilities in radio astronomy. These new developments foreshadow major scientific advances driven by radio observations in the next triennium. We highlight these facility developments in section 3 of this report. A selection of science highlight from this triennium are summarized in section 2.

  8. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    Internet radio is one of the growth areas of the Internet but, as this article will show, is fraught with difficulties and frustration for both the modestly-funded broadcaster (bitcaster) and the listener. The article will illustrate some of these problems by means of a short case study of an exi......Internet radio is one of the growth areas of the Internet but, as this article will show, is fraught with difficulties and frustration for both the modestly-funded broadcaster (bitcaster) and the listener. The article will illustrate some of these problems by means of a short case study...... of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  9. Social cognitive radio networks

    CERN Document Server

    Chen, Xu

    2015-01-01

    This brief presents research results on social cognitive radio networks, a transformational and innovative networking paradigm that promotes the nexus between social interactions and cognitive radio networks. Along with a review of the research literature, the text examines the key motivation and challenges of social cognitive radio network design. Three socially inspired distributed spectrum sharing mechanisms are introduced: adaptive channel recommendation mechanism, imitation-based social spectrum sharing mechanism, and evolutionarily stable spectrum access mechanism. The brief concludes with a discussion of future research directions which ascertains that exploiting social interactions for distributed spectrum sharing will advance the state-of-the-art of cognitive radio network design, spur a new line of thinking for future wireless networks, and enable novel wireless service and applications.

  10. A comparison of transmittance properties between ZnO∶Al films for transparent conductors for solar cells deposited by sputtering of AZO and cosputtering of AZO/ZnO

    Institute of Scientific and Technical Information of China (English)

    LEE Chongmu; YIM Keunbin; CHO Youngjoon; Lee J.G.

    2006-01-01

    Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) andglass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of an AZO target. The dependence of the photoluminescence (PL) and transmittance properties of the AZO films deposited by cosputtering and sputtering on the AZO/ZnO target power ratio, R and the O2/Ar flow ratio, r were investigated, respectively. Only a deep level emission peak appears in the PL spectra of cosputtered AZO films whereas both UV emission and deep level emission peaks are observed in the PL spectra of sputtered AZO films. The absorption edges in the transmittance spectra of the AZO films shift to the lower wavelength region as R and r increase. Effects ofcrystallinity, surface roughness, PL on the transmittance of the AZO films werealso explained using the X-ray diffraction (XRD), atomic force microscopy (AFM), and PL analysis results.

  11. Smart Radio Spectrum Management for Cognitive Radio

    Directory of Open Access Journals (Sweden)

    Partha Pratim Bhattacharya

    2011-08-01

    Full Text Available Today’s wireless networks are characterized by fixed spectrum assignment policy. The limited availablespectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm toexploit the existing wireless spectrum opportunistically. Cognitive radio is a paradigm for wirelesscommunication in which either a network or a wireless node changes its transmission or receptionparameters to communicate efficiently avoiding interference with licensed or unlicensed users. It cancapture best available spectrum to meet user communication requirements (spectrum management. Inthis work, a fuzzy logic based system for spectrum management is proposed where the radio can shareunused spectrum depending on parameters like distance, signal strength, node velocity and availabilityof unused spectrum. The system is simulated and is found to give satisfactory results.

  12. Wireless radio a history

    CERN Document Server

    Coe, Lewis

    2006-01-01

    ""Informative...recommended""--Choice; ""interesting...a good read...well worth reading""--Contact Magazine. This history first looks at Marconi's wireless communications system and then explores its many applications, including marine radio, cellular telephones, police and military uses, television and radar. Radio collecting is also discussed, and brief biographies are provided for the major figures in the development and use of the wireless.

  13. Effective Capacity Analysis of Cognitive Radio Channels for Quality of Service Provisioning

    CERN Document Server

    Akin, Sami

    2009-01-01

    In this paper, cognitive transmission under quality of service (QoS) constraints is studied. In the cognitive radio channel model, it is assumed that the secondary transmitter sends the data at two different average power levels, depending on the activity of the primary users, which is determined by channel sensing performed by the secondary users. A state-transition model is constructed for this cognitive transmission channel. Statistical limitations on the buffer lengths are imposed to take into account the QoS constraints. The maximum throughput under these statistical QoS constraints is identified by finding the effective capacity of the cognitive radio channel. This analysis is conducted for fixed-power/fixed-rate, fixed-power/variable-rate, and variable-power/variable-rate transmission schemes under different assumptions on the availability of channel side information (CSI) at the transmitter. The impact upon the effective capacity of several system parameters, including channel sensing duration, detect...

  14. Remote control radioactive-waste removal system uses modulated laser transmitter

    Science.gov (United States)

    Burcher, E. E.; Kopia, L. P.; Rowland, C. W.; Sinclair, A. R.

    1971-01-01

    Laser remote control system consists of transmitter, auto tracker, and receiver. Transmitter and tracker, packaged together and bore sighted, constitute control station, receiver is slave station. Model has five command channels and optical link operating range of 110 m.

  15. Classics in radio astronomy

    CERN Document Server

    Sullivan, Woodruff Turner

    1982-01-01

    Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave­ lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro­ ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of re...

  16. Cross-layer combining of power control and adaptive modulation with truncated ARQ for cognitive radios

    Institute of Scientific and Technical Information of China (English)

    CHENG Shi-lun; YANG Zhen

    2008-01-01

    To maximize throughput and to satisfy users' requirements in cognitive radios, a cross-layer optimization problem combining adaptive modulation and power control at the physical layer and truncated automatic repeat request at the medium access control layer is proposed. Simulation results show the combination of power control, adaptive modulation, and truncated automatic repeat request can regulate transmitter powers and increase the total throughput effectively.

  17. LOT-G3: Plasma Lamp, Ozonator and CW transmitter

    CERN Document Server

    Gobato, Ricardo; Gobato, Alekssander

    2015-01-01

    The LOT-G3 is designed to be a versatile equipment that perform several simple experiments for use in helping the physics classes for high school. Easy construction, low cost, using easily accessible materials. Its construction involves simple practices and knowledge of electromagnetism. It has the function of a plasma globe to demonstrate the ionization of a low pressure gas, as well as the formation of magnetic field. Can be used as sanitizer closed environments such as automotive vehicles in ozonator function, demonstrating the ionization of oxygen in the atmosphere, producing ozone, essential to life on earth. And as a sparks transmitter, low power, low frequency modulated continuous wave in (CW), for signals in Morse code. Therefore the equipment here called LOT-G3, has three functions: a plasma lamp, ozonator and CW transmitter.

  18. Inductance effects in the high-power transmitter crowbar system

    Science.gov (United States)

    Daeges, J.; Bhanji, A.

    1987-01-01

    The effective protection of a klystron in a high-power transmitter requires the diversion of all stored energy in the protected circuit through an alternate low-impedance path, the crowbar, such that less than 1 joule of energy is dumped into the klystron during an internal arc. A scheme of adding a bypass inductor in the crowbar-protected circuit of the high-power transmitter was tested using computer simulations and actual measurements under a test load. Although this scheme has several benefits, including less power dissipation in the resistor, the tests show that the presence of inductance in the portion of the circuit to be protected severely hampers effective crowbar operation.

  19. Laser transmitter for space-based sodium lidar instrument

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Janches, Diego; Konoplev, Oleg

    2016-05-01

    We are currently developing a laser transmitter to remotely measure Sodium (Na) by adapting existing lidar technology with space flight heritage. The developed instrumentation will serve as the core for the planning of a Heliophysics mission targeted to study the composition and dynamics of Earth's mesosphere based on a spaceborne lidar that will measure the mesospheric Na layer. We present performance results from our laser transmitter development effort with emphasis on wavelength tuning and power scaling of a diode-pumped Q-switched self-Raman c-cut Nd:YVO4 laser with intra-cavity frequency doubling that could produce multi-watt 589 nm wavelength output. We will review technologies that provide strong leverage for the sodium lidar laser system with strong heritage from past and current space flight missions.

  20. Exciter For X-Band Transmitter And Receiver

    Science.gov (United States)

    Johns, Carl E.

    1989-01-01

    Report describes developmental X-band exciter for X-band uplink subsystem of Deep Space Network. X-band transmitter-exciting signal expected to have fractional frequency stability of 5.2 X 10 to negative 15th power during 1,000-second integration period. Generates coherent test signals for S- and X-band Block III translator of Deep Space Network, Doppler-reference signal for associated Doppler-extractor system, first-local-oscillator signal for associated receiver, and reference signal for associated ranging subsystem. Tests of prototype exciter show controlling and monitoring and internal phase-correcting loops perform according to applicable design criteria. Measurements of stability of frequency and of single-sideband noise spectral density of transmitter-exciting signal made subsequently.

  1. Multiband RF circuits and techniques for wireless transmitters

    CERN Document Server

    Chen, Wenhua; Ghannouchi, Fadhel M

    2016-01-01

    This book introduces systematic design methods for passive and active RF circuits and techniques, including state-of-the-art digital enhancement techniques. As the very first book dedicated to multiband RF circuits and techniques, this work provides an overview of the evolution of transmitter architecture and discusses current digital predistortion techniques. Readers will find a collection of novel research ideas and new architectures in concurrent multiband power dividers, power amplifiers and related digital enhancement techniques. This book will be of great interest to academic researchers, R&D engineers, wireless transmitter and protocol designers, as well as graduate students who wish to learn the core architectures, principles and methods of multiband RF circuits and techniques. .

  2. Multiuser MIMO Transmitter Optimization for Inter-Cell Interference Mitigation

    CERN Document Server

    Huh, Hoon; Caire, Giuseppe

    2009-01-01

    The optimization of the transmitter precoder (steering vectors and power allocation) for a MIMO Broadcast Channel (MIMO-BC) subject to general linear constraints is considered. These include various types of system constraints such as sum power, per-antenna or per-group-of-antennas power constraints, and "forbidden interference direction" constraints. We consider the transmitter optimization problem under either the optimal dirty-paper coding and the simple suboptimal linear zero-forcing beamforming strategies. In both cases, we provide numerically efficient algorithms that solve the problem in the most general form. As an application, we consider a multi-cell scenario with partial cell cooperation, where each cell optimizes its precoder by taking into account interference constraints on specific users in adjacent cells. The effectiveness of the proposed method is evaluated in a simple system setting with two adjacent cells, under different fairness criteria that emphasize the role of users near the cell "bou...

  3. Morphology and transmittance of porous alumina on glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Guo Peitao, E-mail: guopeitao@hotmail.com [Wuhan University of Technology. Wuhan (China); Xia Zhilin [Wuhan University of Technology. Wuhan (China); Key Laboratory of Low Dimensional Materials and Application Technology, Xiangtan University, Ministry of Education, Xiangtan (China); Xue Yiyu [Wuhan University of Technology. Wuhan (China); Huang Caihua [China Three Gorges University, Yichang (China); Zhao Lixin [Wuhan University of Technology. Wuhan (China)

    2011-02-01

    The porous optical film has higher threshold of laser-induced damage than densified films, for the study of mechanism of laser-induced damage of porous optical film with ordered pore structure. Porous anodic alumina (PAA) film with high transmittance on glass substrate has been prepared. Aluminum film was deposited on glass substrate by means of resistance and electron beam heat (EBH) evaporation. Porous alumina was prepared in oxalic acid solution under different anodizing conditions. At normal incidence, the optical transmittance spectrum over 300-1000 nm spectra region was obtained by spectrophotometer. SEM was introduced to analysis the morphology of the porous alumina film. The pore aperture increased with the increase of anodizing voltage, which resulted in a rapid decrease of the pore concentration and the optical thickness of porous alumina film. Damage morphology of porous alumina film is found to be typically defects initiated, and the defect is the pore presented on the film.

  4. Transmittance spectroscopy and transmitted multispectral imaging to map covered paints

    Directory of Open Access Journals (Sweden)

    Antonino Cosentino

    2016-01-01

    Full Text Available Transmitted spectroscopy and transmitted multispectral imaging in the 400-900 nm range have been applied for the mapping and tentative identification of paints covered by a white preparation as in the case of a ground laid for reusing a canvas for another painting. These methods can be applied to polychrome works of art, as long as their support and new preparation are sufficiently translucent. This work presents the transmittance spectra acquired from a test board consisting of a prepared canvas with swatches of 54 pigments covered with titanium white and the multispectral images realized with transmitted light to map covered paints on a mock-up painting. It was observed that 18 out of 54 historical pigments provide characteristic transmittance spectra even underneath a titanium white preparation layer and that transmitted light multispectral imaging can map hidden paint layers.

  5. Aerosol Optical Thickness Derived From Atmospheric Transmittance Using Spectroradiometer Measurements

    Science.gov (United States)

    Hwee San, Hslim; Matjafri, M. Z.; Abdullah, Abdul K.; Chow Jeng, C. J.

    section The objective of this study was to test the feasibility of hand held spectroradiometer measurements for the retrieval AOT values Twenty-six stations were chosen randomly around Penang Island and the atmospheric transmittance measurements were collected using a handheld spectroradiometer The corresponding PM10 concentrations were measured using a portable DustTrak Aerosol Monitor 8520 simultaneously with the measurements of the transmittance data The AOT values were calculated using the Beer-Lambert-Bouguer law Linear relationship was found between AOT and PM10 values in this study Finally a PM10 map was created using Kriging interpolation technique The result of the study showed the potential of a spectroradiometer data for the retrieval of AOT and PM10 to provide the air pollution information

  6. A passive transmitter for quantum key distribution with coherent light

    CERN Document Server

    Curty, Marcos; Pruneri, Valerio; Mitchell, Morgan W

    2011-01-01

    Signal state preparation in quantum key distribution schemes can be realized using either an active or a passive source. Passive sources might be valuable in some scenarios; for instance, in those experimental setups operating at high transmission rates, since no externally driven element is required. Typical passive transmitters involve parametric down-conversion. More recently, it has been shown that phase-randomized coherent pulses also allow passive generation of decoy states and Bennett-Brassard 1984 (BB84) polarization signals, though the combination of both setups in a single passive source is cumbersome. In this paper, we present a complete passive transmitter that prepares decoy-state BB84 signals using coherent light. Our method employs sum-frequency generation together with linear optical components and classical photodetectors. In the asymptotic limit of an infinite long experiment, the resulting secret key rate (per pulse) is comparable to the one delivered by an active decoy-state BB84 setup wit...

  7. New digital-input transmitter for missile telemetry

    Science.gov (United States)

    Rieger, J. L.; Woodworth, P. H.

    It is pointed out that telemetry for aircraft and missiles has been in use by the military and its suppliers since the 1950's, using a variety of frequencies and formats. However, the techniques used in airborne telemetry have changed as a consequence of advances in electronic technology. Use of digital pulse-code modulation instead of the analog time-sampled pulse-amptitude modulation (PAM) produced by an analog commutator has advantages in noise performance in instances where the telemetry link is performing near the threshold of noise. The present investigation is concerned with a digital-input transmitter which accepts binary format directly from a TTL source and has applicability in both standard telemetry and encrypted systems. Attention is given to telemetry modulation systems, data encryption requirements, the modulation interface, and transmitter characteristics.

  8. 46 CFR 308.522 - Collateral deposit fund, letter of transmittal, Form MA-302.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Collateral deposit fund, letter of transmittal, Form MA-302. 308.522 Section 308.522 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY... Collateral deposit fund, letter of transmittal, Form MA-302. The standard form of letter of transmittal...

  9. 47 CFR 95.647 - FRS unit and R/C transmitter antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false FRS unit and R/C transmitter antennas. 95.647... transmitter antennas. The antenna of each FRS unit, and the antenna of each R/C station transmitting in the 72-76 MHz band, must be an integral part of the transmitter. The antenna must have no gain (as...

  10. Laser Transmitters for the optical link systems used in CMS

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In the CMS experiment of the now new flagship LHC optical links will be used for the tracker readout system. One part of this components will be semiconductor laser (~50.000 !!!), named correctly: 1310 nm InGaAsP (DCPBH-MQW) edge-emitting laser. They are foreseen as transmitter in the Tx Hybrid part of the optical link system.

  11. Secure Broadcasting with Imperfect Channel State Information at the Transmitter

    KAUST Repository

    Hyadi, Amal

    2015-11-13

    We investigate the problem of secure broadcasting over fast fading channels with imperfect main channel state information (CSI) at the transmitter. In particular, we analyze the effect of the noisy estimation of the main CSI on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. Besides, we consider the realistic case where the transmitter is only aware of the statistics of the eavesdropper’s CSI and not of its channel’s realizations. First, we discuss the common message transmission case where the source broadcasts the same information to all the receivers, and we provide an upper and a lower bounds on the ergodic secrecy capacity. For this case, we show that the secrecy rate is limited by the legitimate receiver having, on average, the worst main channel link and we prove that a non-zero secrecy rate can still be achieved even when the CSI at the transmitter is noisy. Then, we look at the independent messages case where the transmitter broadcasts multiple messages to the receivers, and each intended user is interested in an independent message. For this case, we present an expression for the achievable secrecy sum-rate and an upper bound on the secrecy sum-capacity and we show that, in the limit of large number of legitimate receivers K, our achievable secrecy sum-rate follows the scaling law log((1−) log(K)), where is the estimation error variance of the main CSI. The special cases of high SNR, perfect and no-main CSI are also analyzed. Analytical derivations and numerical results are presented to illustrate the obtained expressions for the case of independent and identically distributed Rayleigh fading channels.

  12. SLVS Transmitter and Receiver for CBM MUCH ASIC

    Science.gov (United States)

    Bulbakov, I.

    2017-01-01

    Scalable Low Voltage Signaling (SLVS) Transmitter (Tx) and Receiver (Rx) IP blocks are designed in the UMC 180 nm CMOS technology as component of the readout ASIC for the muon chambers (MUCH) of the Compressed Baryonic Matter (CBM) experiment at FAIR (Darmstadt, Germany). These blocks are a prototype of the physical layer of the e-link interface that is used for ASIC-GBTx connection. The experimental results at 320 Mbit/s are presented.

  13. Intraperitoneal implantation of life-long telemetry transmitters in otariids

    Directory of Open Access Journals (Sweden)

    Haulena Martin

    2008-12-01

    Full Text Available Abstract Background Pinnipeds, including many endangered and declining species, are inaccessible and difficult to monitor for extended periods using externally attached telemetry devices that are shed during the annual molt. Archival satellite transmitters were implanted intraperitoneally into four rehabilitated California sea lions (Zalophus californianus and 15 wild juvenile Steller sea lions (Eumetopias jubatus to determine the viability of this surgical technique for the deployment of long-term telemetry devices in otariids. The life history transmitters record information throughout the life of the host and transmit data to orbiting satellites after extrusion following death of the host. Results Surgeries were performed under isoflurane anesthesia and single (n = 4 or dual (n = 15 transmitters were inserted into the ventrocaudal abdominal cavity via an 8.5 to 12 cm incision along the ventral midline between the umbilicus and pubic symphysis or preputial opening. Surgeries lasted 90 minutes (SD = 8 for the 19 sea lions. All animals recovered well and were released into the wild after extended monitoring periods from 27 to 69 days at two captive animal facilities. Minimum post-implant survival was determined via post-release tracking using externally attached satellite transmitters or via opportunistic re-sighting for mean durations of 73.7 days (SE = 9.0, Z. californianus and 223.6 days (SE = 71.5, E. jubatus. Conclusion The low morbidity and zero mortality encountered during captive observation and post-release tracking periods confirm the viability of this surgical technique for the implantation of long-term telemetry devices in otariids.

  14. Intraperitoneal implantation of life-long telemetry transmitters in otariids

    OpenAIRE

    Haulena Martin; Horning Markus; Tuomi Pamela A; Mellish Jo-Ann E

    2008-01-01

    Abstract Background Pinnipeds, including many endangered and declining species, are inaccessible and difficult to monitor for extended periods using externally attached telemetry devices that are shed during the annual molt. Archival satellite transmitters were implanted intraperitoneally into four rehabilitated California sea lions (Zalophus californianus) and 15 wild juvenile Steller sea lions (Eumetopias jubatus) to determine the viability of this surgical technique for the deployment of l...

  15. A low-power triple-mode sigma-delta DAC for reconfigurable (WCDMA/TD-SCDMA/GSM) transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Dong; Yi Ting; Hong Zhiliang, E-mail: yiting@fudan.edu.cn [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2011-02-15

    A sigma-delta ({Sigma}{Delta}) DAC with channel filtering for multi-standard wireless transmitters used in the software-defined-radio (SDR) system is presented. The conversion frequency, transfer function of the digital filter and the {Sigma}{Delta} modulator, word-length of the IDAC and cut-off frequency of the analog reconstruction filter can be digitally programmed to satisfy specifications of WCDMA, TD-SCDMA and GSM standards. The {Sigma}{Delta} DAC fabricated in SMIC 0.13-{mu}m CMOS process occupies a die area of 0.72 mm{sup 2}, while consuming 5.52/4.82/3.04 mW in WCDMA/TD-SCDMA/GSM mode from a single 1.2-V supply voltage. The measured SFDR is 62.8/60.1/75.5 dB for WCDMA/TD-SCDMA/GSM mode, respectively. (semiconductor integrated circuits)

  16. A low-power triple-mode sigma-delta DAC for reconfigurable (WCDMA/ TD-SCDMA/GSM) transmitters*

    Institute of Scientific and Technical Information of China (English)

    Qiu Dong; Yi Ting; Hong Zhiliang

    2011-01-01

    A sigma-delta (ΣΔ) DAC with channel filtering for multi-standard wireless transmitters used in the software-defined-radio (SDR) system is presented. The conversion frequency, transfer function of the digital filter and the ΣΔ modulator, word-length of the IDAC and cut-off frequency of the analog reconstruction filter can be digitally programmed to satisfy specifications of WCDMA, TD-SCDMA and GSM standards. The Σ Δ DAC fabricated in SMIC 0.13-μm CMOS process occupies a die area of 0.72 mm2, while consuming 5.52/4.82/3.04 mW in WCDMA/TD-SCDMA/GSM mode from a single 1.2-V supply voltage. The measured SFDR is 62.8/60.1/ 75.5 dB for WCDMA/TD-SCDMA/GSM mode, respectively.

  17. A low-power triple-mode sigma—delta DAC for reconfigurable (WCDMA/TD-SCDMA/GSM) transmitters

    Science.gov (United States)

    Dong, Qiu; Ting, Yi; Zhiliang, Hong

    2011-02-01

    A sigma—delta (ΣΔ) DAC with channel filtering for multi-standard wireless transmitters used in the software-defined-radio (SDR) system is presented. The conversion frequency, transfer function of the digital filter and the ΣΔ modulator, word-length of the IDAC and cut-off frequency of the analog reconstruction filter can be digitally programmed to satisfy specifications of WCDMA, TD-SCDMA and GSM standards. The ΣΔ DAC fabricated in SMIC 0.13-μm CMOS process occupies a die area of 0.72 mm2, while consuming 5.52/4.82/3.04 mW in WCDMA/TD-SCDMA/GSM mode from a single 1.2-V supply voltage. The measured SFDR is 62.8/60.1/75.5 dB for WCDMA/TD-SCDMA/GSM mode, respectively.

  18. Application of the multi-cycle estimator of Doppler and TDOA to passively locating targets exploiting non-cooperative transmitters

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhitao; JIANG Wenli; ZHOU Yiyu

    2003-01-01

    By exploiting the cyclostationary property of non-cooperative source signals, the problem of joint time-difference-of-arrival (TDOA) and Doppler estimation is discussed, and the multi-cycle estimator is developed by generalizing the single-cycle estimator. Utilizing a special commercial FM radio as a non-cooperative transmitter, some practical experiments are carried out. The right estimates of TDOA and Doppler of a particular airplane can really be obtained by processing the measurements with the multi-cycle estimation algorithm. Through adding some slowly time-variant white Gaussian noise to the original measurements, some independent Monte Carlo simulations are performed, and the simulation results reveal that the multi-cycle estimator is really superior to the single-cycle estimator and the conventional cross-correlation method.

  19. Reliability analysis for new technology-based transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Brissaud, Florent, E-mail: florent.brissaud.2007@utt.f [Institut National de l' Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Universite de Technologie de Troyes (UTT), Institut Charles Delaunay (ICD) and STMR UMR CNRS 6279, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Barros, Anne; Berenguer, Christophe [Universite de Technologie de Troyes (UTT), Institut Charles Delaunay (ICD) and STMR UMR CNRS 6279, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Charpentier, Dominique [Institut National de l' Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France)

    2011-02-15

    The reliability analysis of new technology-based transmitters has to deal with specific issues: various interactions between both material elements and functions, undefined behaviours under faulty conditions, several transmitted data, and little reliability feedback. To handle these particularities, a '3-step' model is proposed, based on goal tree-success tree (GTST) approaches to represent both the functional and material aspects, and includes the faults and failures as a third part for supporting reliability analyses. The behavioural aspects are provided by relationship matrices, also denoted master logic diagrams (MLD), with stochastic values which represent direct relationships between system elements. Relationship analyses are then proposed to assess the effect of any fault or failure on any material element or function. Taking these relationships into account, the probabilities of malfunction and failure modes are evaluated according to time. Furthermore, uncertainty analyses tend to show that even if the input data and system behaviour are not well known, these previous results can be obtained in a relatively precise way. An illustration is provided by a case study on an infrared gas transmitter. These properties make the proposed model and corresponding reliability analyses especially suitable for intelligent transmitters (or 'smart sensors').

  20. Life characteristics assessment of the communications technology satellite transmitter experiment package

    Science.gov (United States)

    Smetana, J.; Curren, A. N.

    1979-01-01

    The performance characteristics of the transmitter experiment package (TEP) aboard the Communications Technology Satellite (CTS) measured during its first 2 years in orbit are presented. The TEP consists of a nominal 200 watt output stage tube (OST), a supporting power processing system (PPS), and a variable conductance heat pipe system (VCHPS). The OST, a traveling wave tube augmented with a 10 stage depressed collector has an overall saturated average efficiency of 51.5 percent and an average saturated radio frequency (rf) output power at center band frequency of 240 watts. The PPS operated with a measured efficiency of 86.5 to 88.5 percent. The VCHPS, using three pipes to conduct heat from the PPS and the OST to a 52 by 124 centimeter radiator fin, maintained the PPS baseplate temperature below 50 C for all operating conditions. The TEP performance characteristics presented include frequency response, rf output power, thermal performance, and efficiency. Communications characteristics were evaluated by using both video and audio modulated signals. On four occasions, the TEP experienced temporary thermal control system malfunctions. The anomalies were terminated safely, and the problem was investigated because of the potential for TEP damage due to the signficant temperature increases. Safe TEP operating procedures were established.

  1. Developing high-transmittance heterojunction diodes based on NiO/TZO bilayer thin films.

    Science.gov (United States)

    Huang, Chia-Cheng; Wang, Fang-Hsing; Wu, Chia-Ching; Huang, Hong-Hsin; Yang, Cheng-Fu

    2013-05-01

    In this study, radio frequency magnetron sputtering was used to deposit nickel oxide thin films (NiO, deposition power of 100 W) and titanium-doped zinc oxide thin films (TZO, varying deposition powers) on glass substrates to form p(NiO)-n(TZO) heterojunction diodes with high transmittance. The structural, optical, and electrical properties of the TZO and NiO thin films and NiO/TZO heterojunction devices were investigated with scanning electron microscopy, X-ray diffraction (XRD) patterns, UV-visible spectroscopy, Hall effect analysis, and current-voltage (I-V) analysis. XRD analysis showed that only the (111) diffraction peak of NiO and the (002) and (004) diffraction peaks of TZO were observable in the NiO/TZO heterojunction devices, indicating that the TZO thin films showed a good c-axis orientation perpendicular to the glass substrates. When the sputtering deposition power for the TZO thin films was 100, 125, and 150 W, the I-V characteristics confirmed that a p-n junction characteristic was successfully formed in the NiO/TZO heterojunction devices. We show that the NiO/TZO heterojunction diode was dominated by the space-charge limited current theory.

  2. Demonstration of Space Optical Transmitter Development for Multiple High Frequency Bands

    Science.gov (United States)

    Nguyen, Hung; Simons, Rainee; Wintucky, Edwin; Freeman, Jon

    2013-01-01

    As the demand for multiple radio frequency carrier bands continues to grow in space communication systems, the design of a cost-effective compact optical transmitter that is capable of transmitting selective multiple RF bands is of great interest, particularly for NASA Space Communications Network Programs. This paper presents experimental results that demonstrate the feasibility of a concept based on an optical wavelength division multiplexing (WDM) technique that enables multiple microwave bands with different modulation formats and bandwidths to be combined and transmitted all in one unit, resulting in many benefits to space communication systems including reduced size, weight and complexity with corresponding savings in cost. Experimental results will be presented including the individual received RF signal power spectra for the L, C, X, Ku, Ka, and Q frequency bands, and measurements of the phase noise associated with each RF frequency. Also to be presented is a swept RF frequency power spectrum showing simultaneous multiple RF frequency bands transmission. The RF frequency bands in this experiment are among those most commonly used in NASA space environment communications.

  3. Demonstration of space optical transmitter development for multiple high-frequency bands

    Science.gov (United States)

    Nguyen, Hung; Simons, Rainee; Wintucky, Edwin; Freeman, Jon

    2013-05-01

    As the demand for multiple radio frequency carrier bands continues to grow in space communication systems, the design of a cost-effective compact optical transmitter that is capable of transmitting selective multiple RF bands is of great interest, particularly for NASA Space Communications Network Programs. This paper presents experimental results that demonstrate the feasibility of a concept based on an optical wavelength division multiplexing (WDM) technique that enables multiple microwave bands with different modulation formats and bandwidths to be combined and transmitted all in one unit, resulting in many benefits to space communication systems including reduced size, weight and complexity with corresponding savings in cost. Experimental results will be presented including the individual received RF signal power spectra for the L, C, X, Ku, Ka, and Q frequency bands, and measurements of the phase noise associated with each RF frequency. Also to be presented is a swept RF frequency power spectrum showing simultaneous multiple RF frequency bands transmission. The RF frequency bands in this experiment are among those most commonly used in NASA space environment communications.

  4. Analysis and Compensation of Transmitter and Receiver I/Q Imbalances in Space-Time Coded Multiantenna OFDM Systems

    Directory of Open Access Journals (Sweden)

    Zou Yaning

    2008-01-01

    Full Text Available Abstract The combination of orthogonal frequency division multiplexing (OFDM and multiple-input multiple-output (MIMO techniques has been widely considered as the most promising approach for building future wireless transmission systems. The use of multiple antennas poses then big restrictions on the size and cost of individual radio transmitters and receivers, to keep the overall transceiver implementation feasible. This results in various imperfections in the analog radio front ends. One good example is the so-called I/Q imbalance problem related to the amplitude and phase matching of the transceiver I and Q chains. This paper studies the performance of space-time coded (STC multiantenna OFDM systems under I/Q imbalance, covering both the transmitter and the receiver sides of the link. The challenging case of frequency-selective I/Q imbalances is assumed, being an essential ingredient in future wideband wireless systems. As a practical example, the Alamouti space-time coded OFDM system with two transmit and M receive antennas is examined in detail and a closed-form solution for the resulting signal-to-interference ratio (SIR at the detector input due to I/Q imbalance is derived. This offers a valuable analytical tool for assessing the I/Q imbalance effects in any STC-OFDM system, without lengthy data or system simulations. In addition, the impact of I/Q imbalances on the channel estimation in the STC-OFDM context is also analyzed analytically. Furthermore, based on the derived signal models, a practical pilot-based I/Q imbalance compensation scheme is also proposed, being able to jointly mitigate the effects of frequency-selective I/Q imbalances as well as channel estimation errors. The performance of the compensator is analyzed using extensive computer simulations, and it is shown to virtually reach the perfectly matched reference system performance with low pilot overhead.

  5. Analysis and Compensation of Transmitter and Receiver I/Q Imbalances in Space-Time Coded Multiantenna OFDM Systems

    Directory of Open Access Journals (Sweden)

    Yaning Zou

    2007-12-01

    Full Text Available The combination of orthogonal frequency division multiplexing (OFDM and multiple-input multiple-output (MIMO techniques has been widely considered as the most promising approach for building future wireless transmission systems. The use of multiple antennas poses then big restrictions on the size and cost of individual radio transmitters and receivers, to keep the overall transceiver implementation feasible. This results in various imperfections in the analog radio front ends. One good example is the so-called I/Q imbalance problem related to the amplitude and phase matching of the transceiver I and Q chains. This paper studies the performance of space-time coded (STC multiantenna OFDM systems under I/Q imbalance, covering both the transmitter and the receiver sides of the link. The challenging case of frequency-selective I/Q imbalances is assumed, being an essential ingredient in future wideband wireless systems. As a practical example, the Alamouti space-time coded OFDM system with two transmit and M receive antennas is examined in detail and a closed-form solution for the resulting signal-to-interference ratio (SIR at the detector input due to I/Q imbalance is derived. This offers a valuable analytical tool for assessing the I/Q imbalance effects in any STC-OFDM system, without lengthy data or system simulations. In addition, the impact of I/Q imbalances on the channel estimation in the STC-OFDM context is also analyzed analytically. Furthermore, based on the derived signal models, a practical pilot-based I/Q imbalance compensation scheme is also proposed, being able to jointly mitigate the effects of frequency-selective I/Q imbalances as well as channel estimation errors. The performance of the compensator is analyzed using extensive computer simulations, and it is shown to virtually reach the perfectly matched reference system performance with low pilot overhead.

  6. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2013-01-01

    This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

  7. Radio data archiving system

    Science.gov (United States)

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

    2016-07-01

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

  8. Galactic radio astronomy

    CERN Document Server

    Sofue, Yoshiaki

    2017-01-01

    This book is a concise primer on galactic radio astronomy for undergraduate and graduate students, and provides wide coverage of galactic astronomy and astrophysics such as the physics of interstellar matter and the dynamics and structure of the Milky Way Galaxy and galaxies. Radio astronomy and its technological development have led to significant progress in galactic astronomy and contributed to understanding interstellar matter and galactic structures. The book begins with the fundamental physics of radio-wave radiation, i.e., black body radiation, thermal emission, synchrotron radiation, and HI and molecular line emissions. The author then gives overviews of ingredients of galactic physics, including interstellar matter such as the neutral (HI), molecular hydrogen, and ionized gases, as well as magnetic fields in galaxies. In addition, more advanced topics relevant to the Galaxy and galaxies are also contained here: star formation, supernova remnants, the Galactic Center and black holes, galactic dynamics...

  9. ANTENNA OF RADIO CONTROL

    Directory of Open Access Journals (Sweden)

    Ludwig Ilnytskyi

    2015-12-01

    Full Text Available The article is devoted to current issues in the field of radio monitoring. In this article was considered the antenna of radio control, which represents a grid from three vibrators. Threelement antenna array provides simultaneous control of two radio electronic devices that radiates at frequencies that are close to each other. Antenna system using simple technical means provides noise suppression, even if noise will have the same frequency as useful signal. This makes it possible to use the antenna system in conditions of multibeam wave propagation under the adjustment on the most intense by the power beam. Antenna system makes it possible to measure the electromagnetic field intensity, congestion of the frequency spectrum, direction of noise electromagnetic waves incidence, noise electric field intensity.

  10. Comets at radio wavelengths

    CERN Document Server

    Crovisier, Jacques; Colom, Pierre; Biver, Nicolas

    2016-01-01

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

  11. Pathologic and physiologic effects associated with long-term intracoelomic transmitters in captive Siberian sturgeon

    Science.gov (United States)

    Boone, S. Shaun; Divers, Stephen J.; Camus, Alvin C.; Peterson, Douglas C.; Jennings, Cecil A.; Shelton, James L.; Hernandez, Sonia M.

    2015-01-01

    Intracoelomic transmitters are commonly used to evaluate migratory patterns, distribution, and habitat use of many species of fish. Currently, transmitter implantation relies mostly on the assumption that transmitters do not cause any adverse physiological or pathological effects on the animal. To investigate these effects, we surgically implanted 60 Siberian Sturgeon Acipenser baeri with transmitters that weighed less than 2% of their body weight. Postoperative assessments were conducted at 1, 2, 8, 12, 26, and 55 weeks to evaluate surgical healing and transmitter retention. Blood samples were collected before and after the 55-week study for serum cortisol analysis. Overall transmitter loss was 32%. Minor to moderate adhesions were noted at necropsy but did not appear to affect organ function. One fish was noted to have an intraintestinal transmitter at necropsy, but the fish was in overall good health. Long-term transmitter presence does not appear to increase serum cortisol levels or affect overall growth more than nontransmitter fish. Although long-term telemetry studies can be undertaken with minimal concern for negative physiological or pathological effects from transmitters, researchers should be aware that transmitter loss rates may be higher than previously thought. Mechanisms for transmitter loss may include expulsion through the surgical incision, expulsion through the mucocutaneous junction between the large intestine and the vent, or intraintestinal capture and expulsion through the vent. Received February 10, 2013; accepted June 10, 2013

  12. Effects of Sugars on the Light Transmittance of Tapioca Starch Pastes during Cold Storage

    Directory of Open Access Journals (Sweden)

    Xiaoyu Zhang

    2014-04-01

    Full Text Available The aim of this study is to study the influence of sugars (glucose, sucrose and trehalose on the light transmittance of Tapioca Starch (TS gels during cold storage. The effects of sugars on the light transmittance of TS gels were investigated at the concentration of starch 2% (w:w during cold storage. The results showed the light transmittance of TS gels could be improved by sugar addition, according to the sugar type and concentration. The light transmittance increased with the increase of the concentration of the same kind of sugar. And the improvement of light transmittance with the sugar type was according to the order: trehalose>sucrose>glucose. Whether addition of sugar or not, light transmittance decreased with the extension of storage days. Therefore, light transmittance experiment is a simple and inexpensive method to study the effects of sugars on the retrogradation of starch gels with low-concentration.

  13. Mobile radio channels

    CERN Document Server

    Pätzold, Matthias

    2011-01-01

    Providing a comprehensive overview of the modelling, analysis and simulation of mobile radio channels, this book gives a detailed understanding of fundamental issues and examines state-of-the-art techniques in mobile radio channel modelling. It analyses several mobile fading channels, including terrestrial and satellite flat-fading channels, various types of wideband channels and advanced MIMO channels, providing a fundamental understanding of the issues currently being investigated in the field. Important classes of narrowband, wideband, and space-time wireless channels are explored in deta

  14. Saber sobre la radio

    OpenAIRE

    Mata, María Cristina; Universidad Nacional de Córdoba. Argentina

    1998-01-01

    La autora propone en este artículo repensar los fundamentos sobre los cuales se estructuran las asignaturas y talleres de radio en las escuelas de Comunicación Social en Latinoamérica, con el proposito de romper la escisión  entre teoría/práctica y de no violentar su complejidad: en la radio, entendida como práctica comunicativa, se juega en primer lugar una "red de vinculaciones e intercambios" en condiciones privilegiadas para la dialoguicidad. En un segundo lugar, asociado al desarrollo de...

  15. radio frequency based radio frequency based water level monitor ...

    African Journals Online (AJOL)

    eobe

    used for point level sensing of sediments, liquids with suspended solids, and liquid-liquid interfaces. These sensors sense the decrease or change ... This RF data sent from the transmitter is received by the receiver sub-circuit placed remotely.

  16. e-POP Radio Science Using Amateur Radio Transmissions

    Science.gov (United States)

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

    2015-12-01

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

  17. A reconfigurable radio architecture for Cognitive Radio in emergency networks

    NARCIS (Netherlands)

    Zhang, Q.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

    2006-01-01

    Cognitive Radio has been proposed as a promising technology to solve today’s spectrum scarcity problem. Cognitive Radio is able to sense the spectrum to find the free spectrum, which can be optimally used by Cognitive Radio without causing interference to the licensed user. In the scope of the

  18. A reconfigurable radio architecture for Cognitive Radio in emergency networks

    NARCIS (Netherlands)

    Zhang, Q.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

    2006-01-01

    Cognitive Radio has been proposed as a promising technology to solve today’s spectrum scarcity problem. Cognitive Radio is able to sense the spectrum to find the free spectrum, which can be optimally used by Cognitive Radio without causing interference to the licensed user. In the scope of the Adapt

  19. A Reconfigurable Radio Architecture for Cognitive Radio in Emergency Networks

    NARCIS (Netherlands)

    Zhang, Qiwei; Kokkeler, Andre B.J.; Smit, Gerard J.M.

    2006-01-01

    Cognitive Radio has been proposed as a promising technology to solve today's spectrum scarcity problem. Cognitive Radio is able to sense the spectrum to find the free spectrum, which can be optimally used by Cognitive Radio without causing interference to the licensed user. In the scope of the Adapt

  20. Radio Fatwa : Islamic Tanya-Jawab Programmes on Radio Dakwah

    NARCIS (Netherlands)

    Sunarwoto,

    2012-01-01

    The present article is a study of radio fatwa in Indonesia with special reference to the Tanya-Jawab genres in radio dakwah.The concept of fatwa has changed over time. Such Islamic Tanya-Jawab programmes broadcast on radio dakwah are important to understand how fatwa is disseminated by means of medi

  1. Retention and effects of miniature transmitters in juvenile American eels

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert P.; Janak, Jill; Liss, Stephanie A.; Brown, Richard S.; Deng, Zhiqun; Harnish, Ryan A.

    2017-11-01

    This study was conducted to assess the effects of a non-functional acoustic micro transmitter (tag) on survival, tag loss, and swimming ability of juvenile American eels (Anguilla rostrata). The transmitter was designed for implantation through a < 3 mm opening into the body cavity of anguilliform fishes without the need for sutures. American eels used for the swimming performance study were 113–175 mm (N = 120). There were two treatment groups (tagged and non-tagged), each treatment was split into six size groups of 10 mm for testing. Potential transmitter effects on swimming performance were examined by comparing critical swimming speeds (Ucrit an index of prolonged swimming performance) for tagged and non-tagged eels. There was no significant difference in Ucrit between tagged and non-tagged eels for all of the size groups tested. Median Ucrits for tagged eels ranged from 50.2 cm/s for the smallest group tested (113–119 mm) to 63.9 cm/s for fish 141–150 mm in length. Non-tagged group median Ucrits ranged from 47.2 cm/s for the smallest group to 66.9 cm/s for the 141–150 mm group. An additional 26 eels (115–208 mm) were tagged and held for 38 d (without undergoing swimming performance tests) to determine the effects on survival and tag loss. There was no mortality during the holding period and the majority of the tag loss occurred after 20 days post-tagging, which is the current projected life of the tag. Our results indicate that micro acoustic tags can be successfully implanted in juvenile American eels with no apparent impacts to swimming ability, and would be a viable option for examining eel movement patterns in river systems and near hydroelectric facilities.

  2. Polarized reflectance and transmittance distribution functions of the ocean surface.

    Science.gov (United States)

    Hieronymi, Martin

    2016-07-11

    Two aspects of ocean modelling are treated: representation of ocean waves considering all size-classes of waves and tracing of light-interactions at the wavy sea surface. Nonlinear wave profiles are realized accounting for a wide range of climatologically relevant sea states and wind speeds. Polarized ray tracing is used to investigate air-incident and whitecap-free reflectance and transmittance distributions with high angular resolution subject to sea-characterizing parameters, such as significant wave height, peak wave period, wind speed, and surface roughness. Wave-shadowing effects of incident and multiple reflected rays are fully considered. Their influence mostly starts with incidence angles greater than 60°, i.e., when the sun is near the horizon, and is especially pronounced for steep sea states. The net effect of multiple reflections is a redistribution of reflectance and transmittance fractions in their respective hemispheres and a slight increase of the net transmission of light into the sea. Revised reflectance and transmittance distribution functions, RDF and TDF, are provided depending on surface roughness in terms of the mean-square slope; reference is made to other sea state parameters. In comparison with the slope statistics approach, uncertainties related to sun near the horizon are reduced and on average this study yields somewhat higher reflectance values with some variability related to the sea state. By means of provided data, irradiance and radiance reflectances can be computed using desired sky radiance distributions, e.g., clear sky, overcast or partly cloudy sky, as well as wind or sea state information including wave propagation direction.

  3. BOREAS RSS-1 PARABOLA SSA Surface Reflectance and Transmittance Data

    Science.gov (United States)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Deering, Donald D.; Eck, Thomas F.; Banerjee, Babu

    2000-01-01

    The BOREAS RSS-1 team collected surface reflectance and transmittance data from three forested sites in the SSA. This data set contains averaged reflectance factors and transmitted radiances measured by the PARABOLA instrument at selected sites in the BOREAS SSA at different view angles and at three wavelength bands throughout the day. PARABOLA measurements were made during each of the three BOREAS IFCs during the growing season of 1994 at three SSA tower flux sites as well as during the FFC-T. Additional measurements were made in early and mid-1996 during the FFC-W and during IFC-2. The data are stored in tabular ASCII files.

  4. [GABA, a key transmitter for fetal brain maturation].

    Science.gov (United States)

    Ben-Ari, Yehezkel

    2007-01-01

    GABA, the principal inhibitory transmitter excites immature neurons in all animal species studied. This is due to the higher intracellular concentration of chloride at early developmental stages. Excitatory actions of GABA play an important action in brain maturation. Recent observations also suggest an abrupt shift during delivery that exerts a neuro-protective action contributing to reduce the sequels of trauma and anoxic episodes. These observations have important clinical implications in relation to delivery associated insults but also preterm delivery and more generally consumption of agents during gestation.

  5. Transmitter and Precoding Order Optimization for Nonlinear Downlink Beamforming

    CERN Document Server

    Michel, Thomas

    2007-01-01

    The downlink of a multiple-input multiple output (MIMO) broadcast channel (BC) is considered, where each receiver is equipped with a single antenna and the transmitter performs nonlinear Dirty-Paper Coding (DPC). We present an efficient algorithm that finds the optimum transmit filters and power allocation as well as the optimum precoding order(s) possibly affording time-sharing between individual DPC orders. Subsequently necessary and sufficient conditions for the optimality of an arbitrary precoding order are derived. Based on these we propose a suboptimal algorithm showing excellent performance and having low complexity.

  6. Simplified transmitter design for MIMO systems with channel uncertainty

    Institute of Scientific and Technical Information of China (English)

    DU Juan; KANG Gui-xia; ZHANG Ping

    2009-01-01

    This article investigates transmitter design in Rayleigh fading multiple input multiple output (MIMO) channels with spatial correlation when there are channel uncertainties caused by a combined effect of channel estimation error and limited feedback. To overcome the high computational complexity of the optimal transmit power allocation, a simple and suboptimal allocation is proposed by exploiting the transmission constraint and differentiating a bound based on Jensen inequality on the channel capacity. The simulation results show that the mutual information corresponding to the proposed power allocation closely approaches the channel capacity corresponding to the optimal one and meanwhile the computational complexity is greatly reduced.

  7. Behavioral modelling and predistortion of wideband wireless transmitters

    CERN Document Server

    Ghannouchi, Fadhel M; Helaoui, Mohamed

    2015-01-01

    Covers theoretical and practical aspects related to the behavioral modelling and predistortion of wireless transmitters and power amplifiers. It includes simulation software that enables the users to apply the theory presented in the book. In the first section, the reader is given the general background of nonlinear dynamic systems along with their behavioral modelling from all its aspects. In the second part, a comprehensive compilation of behavioral models formulations and structures is provided including memory polynomial based models, box oriented models such as Hammerstein-based and Wiene

  8. The LOFAR radio environment

    CERN Document Server

    Offringa, A R; Zaroubi, S; van Diepen, G; Martinez-Ruby, O; Labropoulos, P; Brentjens, M A; Ciardi, B; Daiboo, S; Harker, G; Jelic, V; Kazemi, S; Koopmans, L V E; Mellema, G; Pandey, V N; Pizzo, R F; Schaye, J; Vedantham, H; Veligatla, V; Wijnholds, S J; Yatawatta, S; Zarka, P; Alexov, A; Anderson, J; Asgekar, A; Avruch, M; Beck, R; Bell, M; Bell, M R; Bentum, M; Bernardi, G; Best, P; Birzan, L; Bonafede, A; Breitling, F; Broderick, J W; Bruggen, M; Butcher, H; Conway, J; de Vos, M; Dettmar, R J; Eisloeffel, J; Falcke, H; Fender, R; Frieswijk, W; Gerbers, M; Griessmeier, J M; Gunst, A W; Hassall, T E; Heald, G; Hessels, J; Hoeft, M; Horneffer, A; Karastergiou, A; Kondratiev, V; Koopman, Y; Kuniyoshi, M; Kuper, G; Maat, P; Mann, G; McKean, J; Meulman, H; Mevius, M; Mol, J D; Nijboer, R; Noordam, J; Norden, M; Paas, H; Pandey, M; Pizzo, R; Polatidis, A; Rafferty, D; Rawlings, S; Reich, W; Rottgering, H J A; Schoenmakers, A P; Sluman, J; Smirnov, O; Sobey, C; Stappers, B; Steinmetz, M; Swinbank, J; Tagger, M; Tang, Y; Tasse, C; van Ardenne, A; van Cappellen, W; van Duin, A P; van Haarlem, M; van Leeuwen, J; van Weeren, R J; Vermeulen, R; Vocks, C; Wijers, R A M J; Wise, M; Wucknitz, O

    2012-01-01

    Aims: This paper discusses the spectral occupancy for performing radio astronomy with the Low-Frequency Array (LOFAR), with a focus on imaging observations. Methods: We have analysed the radio-frequency interference (RFI) situation in two 24-h surveys with Dutch LOFAR stations, covering 30-78 MHz with low-band antennas and 115-163 MHz with high-band antennas. This is a subset of the full frequency range of LOFAR. The surveys have been observed with a 0.76 kHz / 1 s resolution. Results: We measured the RFI occupancy in the low and high frequency sets to be 1.8% and 3.2% respectively. These values are found to be representative values for the LOFAR radio environment. Between day and night, there is no significant difference in the radio environment. We find that lowering the current observational time and frequency resolutions of LOFAR results in a slight loss of flagging accuracy. At LOFAR's nominal resolution of 0.76 kHz and 1 s, the false-positives rate is about 0.5%. This rate increases approximately linear...

  9. Division x: Radio Astronomy

    NARCIS (Netherlands)

    Taylor, Russ; Chapman, Jessica; Rendong, Nan; Carilli, Christopher; Giovannini, Gabriele; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin; Lazio, Joseph; Morganti, Raffaella; Rubio, Monica; Shastri, Prajval

    This triennium has seen a phenomenal investment in development of observational radio astronomy facilities in all parts of the globe at a scale that significantly impacts the international community. This includes both major enhancements such as the transition from the VLA to the EVLA in North

  10. Educational Broadcasting--Radio.

    Science.gov (United States)

    Ahamed, Uvais; Grimmett, George

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

  11. Albanian: Basic Radio Communications.

    Science.gov (United States)

    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…

  12. Valuing commercial radio licences

    NARCIS (Netherlands)

    Kerste, M.; Poort, J.; van Eijk, N.

    2011-01-01

    Within the EU Regulatory Framework, licensees for commercial radio broadcasting may be charged a fee to ensure optimal allocation of scarce resources but not to maximize public revenues. In this paper, it is described how such a fee can be determined for the purpose of licence renewal or extension.

  13. Zelenchukskaya Radio Astronomical Observatory

    Science.gov (United States)

    Smolentsev, Sergey; Dyakov, Andrei

    2013-01-01

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

  14. Svetloe Radio Astronomical Observatory

    Science.gov (United States)

    Smolentsev, Sergey; Rahimov, Ismail

    2013-01-01

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

  15. Dust tori in radio galaxies

    NARCIS (Netherlands)

    van der Wolk, G.; Barthel, P. D.; Peletier, R. F.; Pel, J. W.

    2010-01-01

    Aims: We investigate the quasar - radio galaxy unification scenario and detect dust tori within radio galaxies of various types. Methods: Using VISIR on the VLT, we acquired sub-arcsecond (~0.40 arcsec) resolution N-band images, at a wavelength of 11.85 μm, of the nuclei of a sample of 27 radio gala

  16. Extragalactic radio continuum surveys and the transformation of radio astronomy

    Science.gov (United States)

    Norris, Ray P.

    2017-10-01

    Next-generation radio surveys are about to transform radio astronomy by discovering and studying tens of millions of previously unknown radio sources. These surveys will provide fresh insights for understanding the evolution of galaxies, measuring the evolution of the cosmic star-formation rate, and rivalling traditional techniques in the measurement of fundamental cosmological parameters. By observing a new volume of observational parameter space, they are also likely to discover unexpected phenomena. This Review traces the evolution of extragalactic radio continuum surveys from the earliest days of radio astronomy to the present, and identifies the challenges that must be overcome to achieve this transformational change.

  17. Considerations on Safety Evaluation of Safety grade Smart Transmitter in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Tae; Jeong, Choong heui [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-05-15

    Non-safety grade smart transmitters have been used for I and C systems of NPPs(Nuclear Power Plants). Smart transmitter is a microprocessor-based device including software and provides capability for digital signals to be communicated on top of the 4-20 mA analog signals. Recently, smart transmitters have been used for safety grade I and C systems as well as non-safety grade I and C system for SKN 3 and 4. Due to potential benefits of smart transmitter, it is anticipated smart transmitters will be widely used safety-related applications at NPPs. For those reasons, smart transmitter's technology and characteristics need to be investigated. Smart transmitters have been used for safety grade as well as non-safety grade I and C system since SKN 3 and 4. Due to potential benefits of smart transmitter, it is anticipated smart transmitters will be widely used safety-related applications at NPPs. For those reasons, smart transmitter's technology and characteristics need to be investigated. To get useful information about that, we surveyed EPRI qualification report, NRC event report, and SKN 3 and 4's review.

  18. INOVASI RADIO KAMPUS (RANCANG BANGUN RADIO UDINUS DENGAN INOVASI TEKNOLOGI @RADIO

    Directory of Open Access Journals (Sweden)

    Wellia Shinta Sari

    2014-08-01

    Full Text Available Perkembangan Teknologi Informasi dan Komunikasi (TIK memaksa industri penyiaran untuk ikut menyesuaikan diri. Radio konvensional bisa jadi akan tertinggal jika tidak melakukan inovasi teknologi yang ada. Begitu juga dengan radio kampus, yang keberadaannya sangat dibutuhkan sebagai wadah kreativitas dan sarana pembelajaran di sebuah universitas, apalagi yang memiliki program studi penyiaran. Radio kampus Suara Dian yang masih konvensional sehingga hampir kehilangan eksistensinya harus segera dibenahi dan dihidupkan kembali dengan mengikuti perkembangan teknologi di era konvergensi. Metode Inovasi teknologi yang bisa dilakukan adalah dengan menggunakan teknologi @Radio Streaming, yang bukan sekedar streaming, tapi juga optimalisasi teknologi yang terintegrasi dinamis melalui RISE (Radio Broadcasting Integrated System. Dengan berbagai fitur unggul dari inovasi teknologi tersebut, maka diharapkan Radio kampus Udinus ”Suara Dian” dapat kembali hidup, berkembang dan lebih kompetitif ditengah industri penyiaran Radio. Kata kunci : radio, kampus, konvergensi, streaming.

  19. Space use of bumblebees (Bombus spp. revealed by radio-tracking.

    Directory of Open Access Journals (Sweden)

    Melanie Hagen

    Full Text Available BACKGROUND: Accurate estimates of movement behavior and distances travelled by animals are difficult to obtain, especially for small-bodied insects where transmitter weights have prevented the use of radio-tracking. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first successful use of micro radio telemetry to track flight distances and space use of bumblebees. Using ground surveys and Cessna overflights in a Central European rural landscape mosaic we obtained maximum flight distances of 2.5 km, 1.9 km and 1.3 km for Bombus terrestris (workers, Bombus ruderatus (worker, and Bombus hortorum (young queens, respectively. Bumblebee individuals used large areas (0.25-43.53 ha within one or a few days. Habitat analyses of one B. hortorum queen at the landscape scale indicated that gardens within villages were used more often than expected from habitat availability. Detailed movement trajectories of this individual revealed that prominent landscape structures (e.g. trees and flower patches were repeatedly visited. However, we also observed long (i.e. >45 min resting periods between flights (B. hortorum and differences in flower-handling between bumblebees with and without transmitters (B. terrestris suggesting that the current weight of transmitters (200 mg may still impose significant energetic costs on the insects. CONCLUSIONS/SIGNIFICANCE: Spatio-temporal movements of bumblebees can now be tracked with telemetry methods. Our measured flight distances exceed many previous estimates of bumblebee foraging ranges and suggest that travelling long distances to food resources may be common. However, even the smallest currently available transmitters still appear to compromise flower handling performance and cause an increase in resting behavior of bees. Future reductions of transmitter mass and size could open up new avenues for quantifying landscape-scale space use of insect pollinators and could provide novel insights into the behavior and

  20. Assessing Timing and Causes of Neonatal Lamb Losses in a Bighorn Sheep Ovis canadensis canadensis Herd via Use of Vaginal Implant Transmitters.

    Science.gov (United States)

    Grigg, Jamin L; Wolfe, Lisa L; Fox, Karen A; Killion, Halcyon J; Jennings-Gaines, Jessica; Miller, Michael W; P Dreher, Brian

    2017-02-13

    We evaluated the use of vaginal implant transmitters (VITs) as a means of detecting, capturing, and radio collaring Rocky Mountain bighorn sheep ( Ovis canadensis canadensis) lambs to estimate survival and to facilitate carcass recovery to assess causes of mortality. We focused on one of several bighorn herds in Colorado, USA, suffering from depressed recruitment that was not preceded by a classic all-age die-off. We captured, radio-collared, diagnosed pregnancy by ultrasound examination, and inserted VITs into 15 pregnant ewes from a herd residing near Granite, Colorado. We were subsequently able to collar a lamb from each of 13 VITs, and two additional lambs opportunistically from ewes without transmitters. As lambs died, we recovered and submitted carcasses for necropsy and laboratory assessment. All lambs captured and one additional lamb (carcass found opportunistically) were dead by about 130 d of age: 11 died of apparent pneumonia (all within 8-10 wk of age), one died from trauma after being kicked or trampled, one was killed by a mountain lion ( Puma concolor ), and three died of starvation likely caused by abandonment after capture. Pneumonic lambs had involvement of Mycoplasma ovipneumoniae and leukotoxigenic Bibersteinia trehalosi . The use of VITs and lamb collars enabled us to efficiently identify pneumonia as the predominant cause of depressed lamb recruitment in this herd; however, we urge care in neonatal lamb handling to minimize abandonment.

  1. Assessment of the calibration curve for transmittance pulse-oximetry

    Science.gov (United States)

    Doronin, A.; Fine, I.; Meglinski, I.

    2011-11-01

    Optical/laser modalities provide a broad variety of practical solutions for clinical diagnostics and therapy in a range from imaging of single cells and molecules to non-invasive biopsy of specific biological tissues and organs tomography. Near-infrared transmittance pulse oximetry with laser diodes is the accepted standard in current clinical practice and widely used for noninvasive monitoring of oxygen saturation in arterial blood hemoglobin. Conceptual design of practical pulse oximetry systems requires careful selection of various technical parameters, including intensity, wavelength, beam size and profile of incident laser radiation, size, numerical aperture of the detector, as well as a clear understanding of how the spatial and temporal structural alterations in biological tissues can be linked with and can be distinguished by variations of these parameters. In current letter utilizing state-of-the-art NVIDEA CUDA technology, a new object oriented programming paradigm and on-line solutions we introduce a computational tool applied for human finger transmittance spectra simulation and assessment of calibration curve for near-infrared transmitted pulseoximetry.

  2. Optimum Transmitter Power Control in WCDMA Cellular Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Power control is an important technique in WCDMA mobile systems for both increasing system capacity and guaranteeing the required QoS (time delay and wireless link transmission quality) of multimedia services. The optimum power control for narrow band CDMA cellular systems is a problem of single threshold optimization. Because these systems have only one type of traffic and have the same QoS requirement. However, WCDMA mobile systems should provide multimedia services and different types of traffic have different QoS requirements. Thus, the power control in WCDMA mobile systems doesn't be a problem of single threshold optimizing, but turns into the optimizing problem of multi-thresholds. In this paper, we analyze the power control problem in WCDMA cellular mobile systems and propose the optimum transmitter power control algorithm. Three criteria to optimize transmitter power levels of multi-thresholds based on grading the priority orders of multimedia services are proposed. Simulation results show that the proposed algorithms are more effective than conventional algorithms and can provide better performance for WCDMA cellular mobile systems.

  3. Rapid light transmittance measurements in paper-based microfluidic devices

    Directory of Open Access Journals (Sweden)

    Christina Swanson

    2015-09-01

    Full Text Available We developed methodology and built a portable reader to assess light transmittance in paper-based microfluidic devices in a highly sensitive, user-friendly and field-appropriate manner. By sandwiching the paper assay between micro-light-emitting diodes and micro-photodetectors, the reader quantifies light transmittance through the paper independent of ambient light conditions. To demonstrate the utility of the reader, we created a single-use paper-based microfluidic assay for measurement of alanine aminotransferase, an indicator of liver health in blood. The paper assay and reader system accurately differentiated alanine aminotransferase levels across the human reference range and demonstrated significant differences at clinically relevant cutoff values. Results were provided within 10 min and were automatically generated without complex image analysis. Performance of this point-of-care diagnostic rivals the accuracy of lab-based spectrometer tests at a fraction of the cost, while matching the timeliness of low-cost portable assays, which have historically shown lower accuracy. This combination of features allows flexible deployment of low cost and quantitative diagnostics to resource-poor settings.

  4. Impact of Improper Gaussian Signaling on the Achievable Rate of Overlay Cognitive Radio

    KAUST Repository

    Amin, Osama

    2017-05-12

    Improper Gaussian signaling (IGS) has been recently shown to provide performance improvements in underlay cognitive radio systems as opposed to the conventional proper Gaussian signaling (PGS) scheme. For the first time, this paper implements IGS scheme in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to support the primary message transmission. On the other hand, the second signal is chosen to be from the IGS scheme in order to reduce the interference effect on the primary receiver. We then optimally design the overlay cognitive radio that employs IGS to maximize the secondary link achievable rate while satisfying the minimum rate requirement of the primary network. In particular, we derive closed form expressions for the circularity coefficient used in the IGS scheme and the power distribution parameters. Simulation results are provided to support our theoretical derivations.

  5. Possible earthquake precursors revealed by LF radio signals

    Directory of Open Access Journals (Sweden)

    P. F. Biagi

    2001-01-01

    Full Text Available Among radio signals, low frequency (LF radio signals lie in the band between 30–300 kHz. Monitoring equipment with the ability to measure the electric strength of such signals at field sites, were designed and assembled in Italy. From 1993 onwards, the electric field strength of the MCO (216 kHz, France broadcasting station has been collecting measurements at two sites in central Italy that were chosen according to very low noise levels. At the end of 1996, radio signals from the CLT (189 kHz, Italy and CZE (270 kHz, Czech Republic broadcasting stations were included in the measurements. Meteorological data from central Italy were also collected over the same time period in order to study the influence of weather conditions on the experimental measurements. During the monitoring period, we observed some evident attenuation of the electric field strength in some of the radio signals at some of the receivers. The duration of the attenuation observed was several days, so it could possibly be related to particular meteorological conditions. On the other hand, this phenomenon might represent precursors of moderate (3.0 M 3.5 earthquakes that occurred near the receivers (within 50 km along the transmitter-receiver path. In this case, it is possible that the pre-seismic processes could have produced irregularities in the troposphere, such as ducts, reflecting layers and scattering zones, so that some local troposphere defocusing of the radio signals might have occurred. These observations were related only to moderate earthquakes and in these cases, suitable meteorological conditions were probably needed to observe the effect. Between February – March 1998, we observed at one measuring site, a significant increase in the CZE electric field strength. Unfortunately, we could not use the data of the other receiver in this case, due to frequent interruptions in the data set. The increase might have been a precursor of the strong seismic sequence (M = 5

  6. Thermal and Nonthermal Radio Galaxies

    CERN Document Server

    Antonucci, Robert

    2011-01-01

    Radio galaxies were discovered and mapped in the 1950s. The optical spectra showed little or no nuclear continuum light. Some also revealed powerful high ionization emission lines, while others showed at most weak low-ionization emission lines. Quasars were found in the 1960s, and their spectra were dominated by powerful continuum radiation which was subsequently identified with optically thick thermal radiation from copious accretion flows, as well as high ionization narrow emission lines, and powerful broad permitted lines. By the 1980s, data from optical polarization and statistics of the radio properties required that many radio galaxies contain hidden quasar nuclei, hidden from the line of sight by dusty, roughly toroidal gas distributions. The radio galaxies with hidden quasars are referred to as "thermal." Do all radio galaxies have powerful hidden quasars? We now know the answer using arguments based on radio, infrared, optical and X-ray properties. Near the top of the radio luminosity function, for F...

  7. THE AUGER ENGINEERING RADIO ARRAY

    Directory of Open Access Journals (Sweden)

    Klaus Weidenhaupt

    2013-12-01

    Full Text Available The Auger Engineering Radio Array currently measures MHz radio emission from extensive air showers induced by high energy cosmic rays with 24 self-triggered radio detector stations. Its unique site, embedded into the baseline detectors and extensions of the Pierre Auger Observatory, allows to study air showers in great detail and to calibrate the radio emission. In its final stage AERA will expand to an area of approximately 20km2 to explore the feasibility of the radio-detection technique for future cosmic-ray detectors. The concept and hardware design of AERA as well as strategies to enable self-triggered radio detection are presented. Radio emission mechanisms are discussed based on polarization analysis of the first AERA data.

  8. Radio observations of Planck clusters

    CERN Document Server

    Kale, Ruta

    2012-01-01

    Recently, a number of new galaxy clusters have been detected by the ESA-Planck satellite, the South Pole Telescope and the Atacama Cosmology Telescope using the Sunyaev-Zeldovich effect. Several of the newly detected clusters are massive, merging systems with disturbed morphology in the X-ray surface brightness. Diffuse radio sources in clusters, called giant radio halos and relics, are direct probes of cosmic rays and magnetic fields in the intra-cluster medium. These radio sources are found to occur mainly in massive merging clusters. Thus, the new SZ-discovered clusters are good candidates to search for new radio halos and relics. We have initiated radio observations of the clusters detected by Planck with the Giant Metrewave Radio Telescope. These observations have already led to the detection of a radio halo in PLCKG171.9-40.7, the first giant halo discovered in one of the new Planck clusters.

  9. Distributed Radio Interferometric Calibration

    CERN Document Server

    Yatawatta, Sarod

    2015-01-01

    Increasing data volumes delivered by a new generation of radio interferometers require computationally efficient and robust calibration algorithms. In this paper, we propose distributed calibration as a way of improving both computational cost as well as robustness in calibration. We exploit the data parallelism across frequency that is inherent in radio astronomical observations that are recorded as multiple channels at different frequencies. Moreover, we also exploit the smoothness of the variation of calibration parameters across frequency. Data parallelism enables us to distribute the computing load across a network of compute agents. Smoothness in frequency enables us reformulate calibration as a consensus optimization problem. With this formulation, we enable flow of information between compute agents calibrating data at different frequencies, without actually passing the data, and thereby improving robustness. We present simulation results to show the feasibility as well as the advantages of distribute...

  10. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2009-01-01

    The recent years have seen breathtaking progress in technology, especially in the receiver and digital technologies relevant for radio astronomy, which has at the same time advanced to shorter wavelengths. This is the updated and completely revised 5th edition of the most used introductory text in radio astronomy. It presents a unified treatment of the entire field from centimeter to sub-millimeter wavelengths. Topics covered include instruments, sensitivity considerations, observational methods and interpretations of the data recorded with both single dishes and interferometers. This text is useful to both students and experienced practicing astronomers. Besides making major updates and additions throughout the book, the authors have re-organized a number of chapters to more clearly separate basic theory from rapidly evolving practical aspects. Further, problem sets have been added at the end of each chapter.

  11. Searches for radio transients

    CERN Document Server

    Bhat, N D R

    2011-01-01

    Exploration of the transient Universe is an exciting and fast-emerging area within radio astronomy. Known transient phenomena range in time scales from sub-nanoseconds to years or longer, thus spanning a huge range in time domain and hinting a rich diversity in their underlying physical processes. Transient phenomena are likely locations of explosive or dynamic events and they offer tremendous potential to uncover new physics and astrophysics. A number of upcoming next-generation radio facilities and recent advances in computing and instrumentation have provided a much needed impetus for this field which has remained a relatively uncharted territory for the past several decades. In this paper we focus mainly on the class of phenomena that occur on very short time scales (i.e. from $\\sim$ milliseconds to $\\sim$ nanoseconds), known as {\\it fast transients}, the detections of which involve considerable signal processing and data management challenges, given the high time and frequency resolutions required in the...

  12. Die radio in Afrika

    Directory of Open Access Journals (Sweden)

    S. de Villiers

    1966-03-01

    Full Text Available Omvang van radio-uitsendings in en na Afrika. — Redes vir die versnelde tempo van uitbreiding. — Radio as die geskikste massa-kommunikasiemiddel vir Afrika. — Faktore wat die verspreiding bemoeilik. — Skouspelagtige toename in luistertalle.Toe Plinius, wat in die jaar 79 oorlede is, in sy „Historia Naturalis” verklaar het dat daar altyd iets nuuts uit Afrika afkomstig is, kon hy nouliks voorsien het dat die „iets" negentien eeue later in die lug sou setel wat hierdie reuse-vasteland oorspan — ’n Babelse spraakverwarring en ’n ongekende, verbete woorde-oorlog in die etergolwe, onder meer daarop bereken om die harte en hoofde van derduisendes te verower.

  13. Probing the intracellular calcium sensitivity of transmitter release during synaptic facilitation

    OpenAIRE

    Felmy, F.; Neher, E.; Schneggenburger, R

    2003-01-01

    In nerve terminals, residual Ca2+ remaining from previous activity can cause facilitation of transmitter release by a mechanism that is still under debate. Here we show that the intracellular Ca2+ sensitivity of transmitter release at the calyx of Held is largely unchanged during facilitation, which leaves an increased microdomain Ca2+ signal as a possible mechanism for facilitation. We measured the Ca2+ dependencies of facilitation, as well as of transmitter release, to estimate the required...

  14. Radio frequency ion source

    CERN Document Server

    Shen Guan Ren; Gao Fu; LiuNaiYi

    2001-01-01

    The study on Radio Frequency Ion Source is mainly introduced, which is used for CIAE 600kV ns Pulse Neutron Generator; and obtained result is also presented. The RF ion source consists of a diameter phi 25 mm, length 200 mm, coefficient of expansion =3.5 mA, beam current on target >=1.5 mA, beam spot =100 h.

  15. Equalization of Multiuser Wireless CDMA Downlink Considering Transmitter Nonlinearity Using Walsh Codes

    Directory of Open Access Journals (Sweden)

    Stephen Z. Pinter

    2007-02-01

    Full Text Available Transmitter nonlinearity has been a major issue in many scenarios: cellular wireless systems have high power RF amplifier (HPA nonlinearity at the base station; satellite downlinks have nonlinear TWT amplifiers in the satellite transponder and multipath conditions in the ground station; and radio-over-fiber (ROF systems consist of a nonlinear optical link followed by a wireless channel. In many cases, the nonlinearity is simply ignored if there is no out-of-band emission. This results in poor BER performance. In this paper we propose a new technique to estimate the linear part of the wireless downlink in the presence of a nonlinearity using Walsh codes; Walsh codes are commonly used in CDMA downlinks. Furthermore, we show that equalizer performance is significantly improved by taking into account the presence of the nonlinearity during channel estimation. This is shown by using a regular decision feedback equalizer (DFE with both wireless and RF amplifier noise. We perform estimation in a multiuser CDMA communication system where all users transmit their signal simultaneously. Correlation analysis is applied to identify the channel impulse response (CIR and the derivation of key correlation relationships is shown. A difficulty with using Walsh codes in terms of their correlations (compared to PN sequences is then presented, as well as a discussion on how to overcome it. Numerical evaluations show a good estimation of the linear system with 54 users in the downlink and a signal-to-noise ratio (SNR of 25 dB. Bit error rate (BER simulations of the proposed identification and equalization algorithms show a BER of 10−6 achieved at an SNR of ∼25 dB.

  16. Equalization of Multiuser Wireless CDMA Downlink Considering Transmitter Nonlinearity Using Walsh Codes

    Directory of Open Access Journals (Sweden)

    Pinter Stephen Z

    2007-01-01

    Full Text Available Transmitter nonlinearity has been a major issue in many scenarios: cellular wireless systems have high power RF amplifier (HPA nonlinearity at the base station; satellite downlinks have nonlinear TWT amplifiers in the satellite transponder and multipath conditions in the ground station; and radio-over-fiber (ROF systems consist of a nonlinear optical link followed by a wireless channel. In many cases, the nonlinearity is simply ignored if there is no out-of-band emission. This results in poor BER performance. In this paper we propose a new technique to estimate the linear part of the wireless downlink in the presence of a nonlinearity using Walsh codes; Walsh codes are commonly used in CDMA downlinks. Furthermore, we show that equalizer performance is significantly improved by taking into account the presence of the nonlinearity during channel estimation. This is shown by using a regular decision feedback equalizer (DFE with both wireless and RF amplifier noise. We perform estimation in a multiuser CDMA communication system where all users transmit their signal simultaneously. Correlation analysis is applied to identify the channel impulse response (CIR and the derivation of key correlation relationships is shown. A difficulty with using Walsh codes in terms of their correlations (compared to PN sequences is then presented, as well as a discussion on how to overcome it. Numerical evaluations show a good estimation of the linear system with 54 users in the downlink and a signal-to-noise ratio (SNR of 25 dB. Bit error rate (BER simulations of the proposed identification and equalization algorithms show a BER of achieved at an SNR of dB.

  17. Emergency Locator Transmitter System Performance During Three Full-Scale General Aviation Crash Tests

    Science.gov (United States)

    Littell, Justin D.; Stimson, Chad M.

    2016-01-01

    Full-scale crash tests were conducted on three Cessna 172 aircraft at NASA Langley Research Center's Landing and Impact Research facility during the summer of 2015. The purpose of the three tests was to evaluate the performance of commercially available Emergency Locator Transmitter (ELT) systems and support development of enhanced installation guidance. ELTs are used to provide location information to Search and Rescue (SAR) organizations in the event of an aviation distress situation, such as a crash. The crash tests simulated three differing severe but survivable crash conditions, in which it is expected that the onboard occupants have a reasonable chance of surviving the accident and would require assistance from SAR personnel. The first simulated an emergency landing onto a rigid surface, while the second and third simulated controlled flight into terrain. Multiple ELT systems were installed on each airplane according to federal regulations. The majority of the ELT systems performed nominally. In the systems which did not activate, post-test disassembly and inspection offered guidance for non-activation cause in some cases, while in others, no specific cause could be found. In a subset of installations purposely disregarding best practice guidelines, failure of the ELT-to-antenna cabling connections were found. Recommendations for enhanced installation guidance of ELT systems will be made to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 229 for consideration for adoption in a future release of ELT minimum operational performance specifications. These recommendations will be based on the data gathered during this test series as well as a larger series of crash simulations using computer models that will be calibrated based on these data

  18. Hybrid recursive active filters for duplexing in RF transmitter front-ends

    Science.gov (United States)

    Gottardo, Giuseppe; Donati, Giovanni; Musolff, Christian; Fischer, Georg; Felgentreff, Tilman

    2016-08-01

    Duplex filters in modern base transceiver stations shape the channel in order to perform common frequency division duplex operations. Usually, they are designed as cavity filters, which are expensive and have large dimensions. Thanks to the emerging digital technology and fast digital converters, it is possible to transfer the efforts of designing analog duplex filters into digital numeric algorithms applied to feedback structures, operating on power. This solution provides the shaping of the signal spectrum directly at the output of the radio frequency (RF) power amplifiers (PAs) relaxing the transmitter design especially in the duplexer and in the antenna sections. The design of a digital baseband feedback applied to the analog power RF amplifiers (hybrid filter) is presented and verified by measurements. A model to describe the hybrid system is investigated, and the relation between phase and resonance peaks of the resulting periodic band-pass transfer function is described. The stability condition of the system is analyzed using Nyquist criterion. A solution involving a number of digital feedback and forward branches is investigated defining the parameters of the recursive structure. This solution allows the closed loop system to show a periodic band pass with up to 500 kHz bandwidth at the output of the RF amplifier. The band-pass magnitude reaches up to 17 dB selectivity. The rejection of the PA noise in the out-of-band frequencies is verified by measurements. The filter is tested with a modulated LTE (Long Term Evolution) signal showing an ACPR (Adjacent Channel Power Ratio) enhancement of 10 dB of the transmitted signal.

  19. Modified method for external attachment of transmitters to birds using two subcutaneous anchors

    Science.gov (United States)

    Lewis, T.L.; Flint, P.L.

    2008-01-01

    Of the transmitter attachment techniques for birds, the subcutaneous anchor provides a secure attachment that yields relatively few secondary effects. However, the use of subcutaneous anchors has been limited by transmitter size and retention time. Using a modified method of attachment that utilized two subcutaneous anchors, we deployed 69 GPS transmitters, plus 13 VHF transmitters that were similar in size and weight to GPS models, on Pacific Black Brant (Branta bernicla nigricans). Prior to our study, only harnesses were used for attaching GPS transmitters on birds, mainly because GPS transmitters are too large for other external attachment techniques and implantation in the body cavity attenuates the GPS signal. Thus, to increase the size capacity of anchor attachment and to avoid the well-documented negative effects of harnesses on behavior and survival, we added a second anchor at the transmitter's posterior end. The double-anchor attachment technique was quickly and easily accomplished in the field, requiring bird handling times of killed by hunters (3-6 mo after deployment) retained their GPS transmitters. For studies involving the use of relatively large transmitters, the double-anchor method appears to provide a viable alternative for external attachment. ?? 2008 Association of Field Ornithologists.

  20. All polymer chip for amperometric studies of transmitter release from large groups of neuronal cells

    DEFF Research Database (Denmark)

    Larsen, Simon T.; Taboryski, Rafael

    2012-01-01

    We present an all polymer electrochemical chip for simple detection of transmitter release from large groups of cultured PC 12 cells. Conductive polymer PEDOT:tosylate microelectrodes were used together with constant potential amperometry to obtain easy-to-analyze oxidation signals from potassium......-induced release of transmitter molecules. The nature of the resulting current peaks is discussed, and the time for restoring transmitter reservoirs is studied. The relationship between released transmitters and potassium concentration was found to fit to a sigmoidal dose–response curve. Finally, we demonstrate...

  1. Integrated DSP/RF design for an MSAT transmitter

    Science.gov (United States)

    Stapleton, S. P.; Cavers, J. K.

    1990-01-01

    In mobile radio systems, the relatively inefficient use of the spectrum by existing Frequency Modulation (FM) techniques is limiting the available channels. Linear modulation methods are thought to provide the necessary push into more efficient usage of the spectrum. The limitation, to date, of the linear modulation techniques is the fact that the nonlinear power amplifier tends to spread the spectrum and thus offset any spectrum efficiency advantage. Linearization techniques are presently being investigated, in the literature, in order to recover some of the lost spectrum, due to spreading. To this end, digital signal processing (DSP) techniques are thought to provide real time predistortion methods. Some of the complex modulation blocks, normally confined to analog circuitry, are being implemented using DSP circuitry. This paper will address the linearization techniques, for mobile satellite (MSAT) transceivers, that use an integrated DSP/radio frequency design.

  2. Comparison between ASHRAE and ISO thermal transmittance calculation methods

    DEFF Research Database (Denmark)

    Blanusa, Petar; Goss, William P.; Roth, Hartwig

    2007-01-01

    the Heat Transfer and Total Optical Properties of Fenestration Products, Public Review Draft of Standard 142P, American Society of Heating, Refrigerating and Air Conditioning Engineers, Atlanta, 1998]) and in Europe [ISO 10077-2. Thermal Performance of Windows, Doors and Shutters-Calculation of Thermal...... Transmittance-Part 2: Numerical Method for Frames, International Standards Organization, Geneva, 2003]. The two approaches, called the ASHRAE and ISO methods, are different in the way they treat the effect of the glazing spacer on the heat transfer through the frame and the glazing unit near the frame....... The ASHRAE method assumes that the spacer effects both the heat transfer through the frame and the heat transfer through the glazing in an "edge-of glass" region 63.5mm (2.5in.) from the glazing/frame sight line. The ISO method assumes that the additional heat transfer due to the existence of the spacer...

  3. The 20 GHz spacecraft FET solid state transmitter

    Science.gov (United States)

    1983-01-01

    The engineering development of a solid state transmitter amplifier operating in the 20 GHz frequency band using GaAs field effect transistors (FETs) was detailed. The major efforts include GaAs FET device development, single-ended amplifier stage, balanced amplifier stage, cascaded stage and radial combiner designs, and amplifier integration and test. A multistage GaAs FET amplifier capable of 8.2 W CW output over the 17.9 to 19.1 GHz frequency band was developed. The GaAs FET devices developed represent state of the art FET power device technology. Further device improvements are necessary to increase the bandwidth to 2.5 GHz, improve dc-to-RF efficiency, and increase power capability at the device level. Higher power devices will simplify the amplifier combining scheme, reducing the size and weight of the overall amplifier.

  4. Leaf Relative Water Content Estimated from Leaf Reflectance and Transmittance

    Science.gov (United States)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2016-01-01

    Remotely sensing the water status of plants and the water content of canopies remain long term goals of remote sensing research. In the research we report here, we used optical polarization techniques to monitor the light reflected from the leaf interior, R, as well as the leaf transmittance, T, as the relative water content (RWC) of corn (Zea mays) leaves decreased. Our results show that R and T both change nonlinearly. The result show that the nonlinearities cancel in the ratio R/T, which appears linearly related to RWC for RWC less than 90%. The results suggest that potentially leaf water status and perhaps even canopy water status could be monitored starting from leaf and canopy optical measurements.

  5. Electromagnetic Cavity Effects from Transmitters Inside a Launch Vehicle Fairing

    Science.gov (United States)

    Trout, Dawn H.; Wahid, Parveen F.; Stanley, James E.

    2009-01-01

    This paper provides insight into the difficult analytical issue for launch vehicles and spacecraft that has applicability outside of the launch industry. Radiation from spacecraft or launch vehicle antennas located within enclosures in the launch vehicle generates an electromagnetic environment that is difficult to accurately predict. This paper discusses the test results of power levels produced by a transmitter within a representative scaled vehicle fairing model and provides preliminary modeling results at the low end of the frequency test range using a commercial tool. Initially, the walls of the fairing are aluminum and later, layered with materials to simulate acoustic blanketing structures that are typical in payload fairings. The effects of these blanketing materials on the power levels within the fairing are examined.

  6. Comparison between ASHRAE and ISO thermal transmittance calculation methods

    DEFF Research Database (Denmark)

    Blanusa, Petar; Goss, William P.; Roth, Hartwig

    2007-01-01

    the Heat Transfer and Total Optical Properties of Fenestration Products, Public Review Draft of Standard 142P, American Society of Heating, Refrigerating and Air Conditioning Engineers, Atlanta, 1998]) and in Europe [ISO 10077-2. Thermal Performance of Windows, Doors and Shutters-Calculation of Thermal...... Transmittance-Part 2: Numerical Method for Frames, International Standards Organization, Geneva, 2003]. The two approaches, called the ASHRAE and ISO methods, are different in the way they treat the effect of the glazing spacer on the heat transfer through the frame and the glazing unit near the frame....... The ASHRAE method assumes that the spacer effects both the heat transfer through the frame and the heat transfer through the glazing in an "edge-of glass" region 63.5mm (2.5in.) from the glazing/frame sight line. The ISO method assumes that the additional heat transfer due to the existence of the spacer...

  7. Activity and food choice of piscivorous perch ( Perca fluviatilis ) in a eutrophic shallow lake: a radio-telemetry study

    DEFF Research Database (Denmark)

    Jacobsen, Lene; Berg, Søren; Broberg, M.

    2002-01-01

    1. Radio transmitters were implanted in large perch (27-37 cm) in a shallow lake in Denmark. Between 6 and 13 perch were tracked every 3 h for 24-h periods twice (summer) or once a month (winter) from August 1997 to July 1998. Activity levels were recorded as minimum distance moved per hour. 2. N......+ planktivorous fish in lakes and has potential implications for pelagic food web structure and lake management by biomanipulation...

  8. Compact radio cores in radio-quiet AGNs

    CERN Document Server

    Maini, Alessandro; Norris, Ray P; Giovannini, Gabriele; Spitler, Lee R

    2016-01-01

    The mechanism of radio emission in radio-quiet (RQ) active galactic nuclei (AGN) is still debated and might arise from the central AGN, from star formation activity in the host, or from either of these sources. A direct detection of compact and bright radio cores embedded in sources that are classified as RQ can unambiguously determine whether a central AGN significantly contributes to the radio emission. We search for compact, high-surface-brightness radio cores in RQ AGNs that are caused unambiguously by AGN activity. We used the Australian Long Baseline Array to search for compact radio cores in four RQ AGNs located in the Extended Chandra Deep Field South (ECDFS). We also targeted four radio-loud (RL) AGNs as a control sample. We detected compact and bright radio cores in two AGNs that are classified as RQ and in one that is classified as RL. Two RL AGNs were not imaged because the quality of the observations was too poor. We report on a first direct evidence of radio cores in RQ AGNs at cosmological reds...

  9. Public Safety Transmitter Towers, Public Safety Transmitter Towers, Published in 2008, 1:24000 (1in=2000ft) scale, Lafayette County Land Records.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Public Safety Transmitter Towers dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Field Survey/GPS information as of 2008. It...

  10. ULF radio monitoring network in a seismic area

    Science.gov (United States)

    Toader, Victorin; Moldovan, Iren-Adelina; Ionescu, Constantin; Marmureanu, Alexandru

    2017-04-01

    ULF monitoring is a part of a multidisciplinary network (AeroSolSys) located in Vrancea (Curvature Carpathian Mountains). Four radio receivers (100 kHz - microwave) placed on faults in a high seismic area characterized by deep earthquakes detect fairly weak radio waves. The radio power is recorded in correlation with many other parameters related to near surface low atmosphere phenomena (seismicity, solar radiation, air ionization, electromagnetic activity, radon, CO2 concentration, atmospheric pressure, telluric currents, infrasound, seismo-acoustic emission, meteorological information). We follow variations in the earth's surface propagate radio waves avoiding reflection on ionosphere. For this reason the distance between stations is less than 60 km and the main source of emission is near (Bod broadcasting transmitter for long- and medium-wave radio, next to Brasov city). In the same time tectonic stress affects the radio propagation in air and it could generates ULF waves in ground (LAI coupling). To reduce the uncertainty is necessary to monitor a location for extended periods of time to outline local and seasonal fluctuations. Solar flares do not affect seismic activity but they produce disturbances in telecommunications networks and power grids. Our ULF monitoring correlated with two local magnetometers does not indicate this so far with our receivers. Our analysis was made during magnetic storms with Kp 7 and 8 according to NOAA satellites. To correlate the results we implemented an application that monitors the satellite EUTELSAT latency compared to WiMAX land communication in the same place. ULF band radio monitoring showed that our receiver is dependent on temperature and that it is necessary to introduce a band pass filter in data analysis. ULF data acquisition is performed by Kinemetrics and National Instruments digitizers with a sampling rate of 100 Hz in Miniseed format and then converted into text files with 1 Hz rate for analysis in very low

  11. Radio emision from supernova remnants

    Science.gov (United States)

    Dubner, G.

    2016-06-01

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

  12. Flexible Adaptation in Cognitive Radios

    CERN Document Server

    Li, Shujun

    2013-01-01

    This book provides an introduction to software-defined radio and cognitive radio, along with methodologies for applying knowledge representation, semantic web, logic reasoning and artificial intelligence to cognitive radio, enabling autonomous adaptation and flexible signaling. Readers from the wireless communications and software-defined radio communities will use this book as a reference to extend software-defined radio to cognitive radio, using the semantic technology described. Readers with a background in semantic web and artificial intelligence will find in this book the application of semantic web and artificial intelligence technologies to wireless communications. For readers in networks and network management, this book presents a new approach to enable interoperability, collaborative optimization and flexible adaptation of network components. Provides a comprehensive ontology covering the core concepts of wireless communications using a formal language; Presents the technical realization of using a ...

  13. Surgical implantation of temperature-sensitive transmitters and data-loggers to record body temperature in koalas (Phascolarctos cinereus).

    Science.gov (United States)

    Adam, D; Johnston, S D; Beard, L; Nicholson, V; Lisle, A; Gaughan, J; Larkin, R; Theilemann, P; Mckinnon, A; Ellis, W

    2016-01-01

    Under predicted climate change scenarios, koala distribution in Australia is expected to be adversely affected. Recent studies have attempted to identify suitable habitat, based on models of bioclimatic regions, but to more accurately reflect the thermal tolerance and behavioural adaptations of the various regional populations, the koala's response to periods of heat stress will need to be investigated at the individual animal level. To explore the safety and suitability of temperature-sensitive intra-abdominal implants for monitoring core body temperature in the koala. A temperature-sensitive radio transmitter and thermal iButton data-logger, waxed together as a package, were surgically implanted into the abdominal cavity of four captive koalas. In one animal the implant was tethered and in the other three, it was left free-floating. After 3 months, the implants were removed and all four koalas recovered without complications. The tethering of the package in the one koala resulted in minor inflammation and adhesion, so this practice was subsequently abandoned. The free-floating deployments were complication-free and revealed a diurnal body temperature rhythm, with daily ranges of 0.4-2.8°C. The minimum recorded body temperature was 34.2°C and the maximum was 37.7°C. The difference in the readings obtained from the transmitters and iButtons never exceeded 0.3°C. The suitability of the surgical approach was confirmed, from both the animal welfare and data collection points of view. © 2016 Australian Veterinary Association.

  14. Software defined radio architectures evaluation

    OpenAIRE

    Palomo, Alvaro; Villing, Rudi; Farrell, Ronan

    2008-01-01

    This paper presents an performance evaluation of GNU Radio and OSSIE, two open source Software Defined Radio (SDR) architectures. The two architectures were compared by running implementations of a BPSK waveform utilising a software loopback channel on each. The upper bound full duplex throughput was found to be around 700kbps in both cases, though OSSIE was slightly faster than GNU Radio. CPU and memory loads did not differ significantly.

  15. Uzaybimer Radio Telescope Control System

    Science.gov (United States)

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

    2016-12-01

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

  16. Radio frequency sensing measurements and methods for location classification in wireless networks

    Science.gov (United States)

    Maas, Dustin C.

    The wireless radio channel is typically thought of as a means to move information from transmitter to receiver, but the radio channel can also be used to detect changes in the environment of the radio link. This dissertation is focused on the measurements we can make at the physical layer of wireless networks, and how we can use those measurements to obtain information about the locations of transceivers and people. The first contribution of this work is the development and testing of an open source, 802.11b sounder and receiver, which is capable of decoding packets and using them to estimate the channel impulse response (CIR) of a radio link at a fraction of the cost of traditional channel sounders. This receiver improves on previous implementations by performing optimized matched filtering on the field-programmable gate array (FPGA) of the Universal Software Radio Peripheral (USRP), allowing it to operate at full bandwidth. The second contribution of this work is an extensive experimental evaluation of a technology called location distinction, i.e., the ability to identify changes in radio transceiver position, via CIR measurements. Previous location distinction work has focused on single-input single-output (SISO) radio links. We extend this work to the context of multiple-input multiple-output (MIMO) radio links, and study system design trade-offs which affect the performance of MIMO location distinction. The third contribution of this work introduces the "exploiting radio windows" (ERW) attack, in which an attacker outside of a building surreptitiously uses the transmissions of an otherwise secure wireless network inside of the building to infer location information about people inside the building. This is possible because of the relative transparency of external walls to radio transmissions. The final contribution of this dissertation is a feasibility study for building a rapidly deployable radio tomographic (RTI) imaging system for special operations forces

  17. Radio-induced brain lesions

    Directory of Open Access Journals (Sweden)

    Gorgan Mircea Radu

    2014-03-01

    Full Text Available Introduction : Radiotherapy, an important tool in multimodal oncologic treatment, can cause radio-induced brain lesion development after a long period of time following irradiation.

  18. Internet Resources for Radio Astronomy

    Science.gov (United States)

    Andernach, H.

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

  19. Radio Frequency Anechoic Chamber Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the design, manufacture, and test of antenna systems. The facility is also used as an electromagnetic compatibility/radio frequency interference...

  20. Military Mail Radio

    Directory of Open Access Journals (Sweden)

    Bîlbîie Răduţ

    2015-12-01

    Full Text Available Cultural and scientific personalities from the army, military experts and creators of the doctrine have collaborated with the radio from the beginnings of radiophony, the educational role of this new, persuasive communication channel being evident not only for Romania or the Romanian army but also for all the countries that had radiophony services. This happens in the context of the end of the crisis and the start of economic and social development, promoting culture, creating a solid class of peasants with a certain social status, in villages, together with the priest, teacher and gendarme, increasing of the number of subscriptions and development of the Romanian radiophony.

  1. Radio Frequency Identification

    Indian Academy of Sciences (India)

    V Rajaraman

    2017-06-01

    Radio Frequency Identification (RFID) has been around sinceearly 2000. Its use has currently become commonplace as thecost of RFID tags has rapidly decreased. RFID tags have alsobecome more ‘intelligent’ with the incorporation of processorsand sensors in them. They are widely used now in manyinnovative ways. RFIDs are an integral part of Internet ofThings (IOT) and IT systems of smart cities. In this article,we introduce the technology used by RFID systems, illustratetheir use in several applications, and discuss problems of privacyand security when they are used.

  2. Flexible Frequency Discrimination Subsystems for Reconfigurable Radio Front Ends

    Directory of Open Access Journals (Sweden)

    Carey-Smith Bruce E

    2005-01-01

    Full Text Available The required flexibility of the software-defined radio front end may currently be met with better overall performance by employing tunable narrowband circuits rather than pursuing a truly wideband approach. A key component of narrowband transceivers is appropriate filtering to reduce spurious spectral content in the transmitter and limit out-of-band interference in the receiver. In this paper, recent advances in flexible, frequency-selective, circuit components applicable to reconfigurable SDR front ends are reviewed. The paper contains discussion regarding the filtering requirements in the SDR context and the use of intelligent, adaptive control to provide environment-aware frequency discrimination. Wide tuning-range frequency-selective circuit elements are surveyed including bandpass and bandstop filters and narrowband tunable antennas. The suitability of these elements to the mobile wireless SDR environment is discussed.

  3. Beamforming and Rate Allocation in MISO Cognitive Radio Networks

    CERN Document Server

    Tajer, Ali; Wang, Xiaodong

    2009-01-01

    We consider decentralized multi-antenna cognitive radio networks where secondary (cognitive) users are granted simultaneous spectrum access along with license-holding (primary) users. We treat the problem of distributed beamforming and rate allocation for the secondary users such that the minimum weighted secondary rate is maximized. Such an optimization is subject to (1) a limited weighted sum-power budget for the secondary users and (2) guaranteed protection for the primary users in the sense that the interference level imposed on each primary receiver does not exceed a specified level. Based on the decoding method deployed by the secondary receivers, we consider three scenarios for solving this problem. In the first scenario each secondary receiver decodes only its designated transmitter while suppressing the rest as Gaussian interferers (single-user decoding). In the second case each secondary receiver employs the maximum likelihood decoder (MLD) to jointly decode all secondary transmissions, and in the t...

  4. Flexible Frequency Discrimination Subsystems for Reconfigurable Radio Front Ends

    Directory of Open Access Journals (Sweden)

    Carey-Smith Bruce E.

    2005-01-01

    Full Text Available The required flexibility of the software-defined radio front end may currently be met with better overall performance by employing tunable narrowband circuits rather than pursuing a truly wideband approach. A key component of narrowband transceivers is appropriate filtering to reduce spurious spectral content in the transmitter and limit out-of-band interference in the receiver. In this paper, recent advances in flexible, frequency-selective, circuit components applicable to reconfigurable SDR front ends are reviewed. The paper contains discussion regarding the filtering requirements in the SDR context and the use of intelligent, adaptive control to provide environment-aware frequency discrimination. Wide tuning-range frequency-selective circuit elements are surveyed including bandpass and bandstop filters and narrowband tunable antennas. The suitability of these elements to the mobile wireless SDR environment is discussed.

  5. On-Line Hyperspectral Transmittance Imaging for Internal Defect Detection of Pickling Cucumbers

    Science.gov (United States)

    Hyperspectral imaging technique under transmittance mode was investigated for detection of internal defect in pickling cucumbers such as carpel suture separation or hollow cucumbers caused by mechanical stress. A prototype of on-line hyperspectral transmittance imaging system was developed for real...

  6. Effect of package light transmittance on vitamin content of milk. Part 2: UHT whole milk

    NARCIS (Netherlands)

    Saffert, A.; Pieper, G.; Jetten, J.

    2008-01-01

    This work is the second part of a milk study evaluating the effect of package light transmittance on the vitamin content of milk, in this case on UHT whole milk. The milk was stored at three different light intensities in polyethylene terephthalate (PET) bottles with varying light transmittance as

  7. Negative control in two-component signal transduction by transmitter phosphatase activity.

    Science.gov (United States)

    Huynh, TuAnh Ngoc; Stewart, Valley

    2011-10-01

    Bifunctional sensor transmitter modules of two-component systems exert both positive and negative control on the receiver domain of the cognate response regulator. In negative control, the transmitter module accelerates the rate of phospho-receiver dephosphorylation. This transmitter phosphatase reaction serves the important physiological functions of resetting response regulator phosphorylation level and suppressing cross-talk. Although the biochemical reactions underlying positive control are reasonably well understood, the mechanism for transmitter phosphatase activity has been unknown. A recent hypothesis is that the transmitter phosphatase reaction is catalysed by a conserved Gln, Asn or Thr residue, via a hydrogen bond between the amide or hydroxyl group and the nucleophilic water molecule in acyl-phosphate hydrolysis. This hypothetical mechanism closely resembles the established mechanisms of auxiliary phosphatases such as CheZ and CheX, and may be widely conserved in two-component signal transduction. In addition to the proposed catalytic residues, transmitter phosphatase activity also requires the correct transmitter conformation and appropriate interactions with the receiver. Evidence suggests that the phosphatase-competent and autokinase-competent states are mutually exclusive, and the corresponding negative and positive activities are likely to be reciprocally regulated through dynamic control of transmitter conformations. © 2011 Blackwell Publishing Ltd.

  8. Effect of package light transmittance on vitamin content of milk. Part 2: UHT whole milk

    NARCIS (Netherlands)

    Saffert, A.; Pieper, G.; Jetten, J.

    2008-01-01

    This work is the second part of a milk study evaluating the effect of package light transmittance on the vitamin content of milk, in this case on UHT whole milk. The milk was stored at three different light intensities in polyethylene terephthalate (PET) bottles with varying light transmittance as d

  9. Subcutaneous implantation of satellite transmitters with percutaneous antennae into male polar bears (Ursus maritimus)

    Science.gov (United States)

    Mulcahy, D.M.; Garner, G.

    1999-01-01

    Male polar bears (Ursus maritimus) have not been successfully instrumented with satellite transmitters because they readily shed collar-mounted transmitters. Seven male polar bears were captured on the pack ice off the northern coast of Alaska and surgically implanted with satellite transmitters with percutaneous antennae into the subcutaneous space of the dorsal cervical region. Transmitters failed prematurely with lifetimes of 30-161 days (x?? = 97 days). Efforts to relocate implanted bears after transmitters failed were not successful. The mean number of location solutions per transmitter was 204 (range 118-369). An average of 10% and 19% of the locations were accurate to < 150 m and to 150-350 m, respectively. Our successful tracking of male polar bears, the high quality of locations obtained from transmitters with percutaneous antennae implanted in the subcutaneous space, and the low visibility of such units make further technical development worthwhile if the reason for premature failure of the transmitters can be determined. Copyright 1999 by American Association of Zoo Veterinarians.

  10. Integrated S-band transmitter with on-chip DC-DC converter and control loop

    NARCIS (Netherlands)

    Brouzes, H.; Geurts, S.; Besselink, M.; Telli, A.; Hek, A.P. de; Bent, G. van der; Vliet, F.E. van

    2012-01-01

    A highly integrated high-power transmitter has been designed in a high breakdown GaAs MMIC technology. The transmitter includes, on top of an S-Band 10 W class-F HPA, a DC/DC converter and its associated gate driver, the full voltage regulation control loop, which provides a significant step for pha

  11. Disturbances in LF radio-signals as seismic precursors

    Directory of Open Access Journals (Sweden)

    S. P. Kingsley

    2001-06-01

    Full Text Available Low Frequency (LF radio signals lie in the band 30-300 kHz. Monitoring equipment able to measure the electric strength of such signals, at field sites with very low noise levels, were designed and assembled in Italy. From 1993 onwards, the electric field strength of the MCO (216 kHz, France broadcasting station has been measured at two sites in Central Italy. At the end of 1996, radio signals from the CLT (189 kHz, Italy and the CZE (270 kHz, Czech Republic broadcasting stations were included in the measurements. During this monitoring period, evident attenuation of the electric field strength in some of the radio signals was observed at some of the receivers. The duration of the attenuation observed was several days and so it could have been related to particular meteorological conditions. On the other hand, this phenomenon could also represent precursors of moderate (3.0 =M =3.5 earthquakes that occurred near the receivers (within 50 km along the transmitter-receiver path. In this case it is possible that some local troposphere defocusing of the radio signals, produced by the pre-seismic processes, might have occurred. These observations were related only to moderate earthquakes and in these cases it may be that suitable meteorological conditions are needed to observe the effect. During February-March 1998 at one measuring site, we observed a significant increase in the CZE electric field strength. Unfortunately, the data of the other receiver could not be used in this case because of frequent interruptions in the recordings. The increase might have been a precursor of a strong earthquake (M = 5.3 that occurred on March 26, 1998 in the Umbria-Marche zone at a location over 100 km from the receiver, but which lay along the transmitter-receiver path. In this case, it is possible that an ionospheric disturbance, produced by the pre-seismic processes, might have occurred. If this pre-seismic behaviour of the LF signals could be confirmed then this

  12. Evaluation of GNU Radio Platform Enhanced for Hardware Accelerated Radio Design

    OpenAIRE

    Karve, Mrudula Prabhakar

    2010-01-01

    The advent of software radio technology has enabled radio developers to design and imple- ment radios with great ease and flexibility. Software radios are effective in experimentation and development of radio designs. However, they have limitations when it comes to high- speed, high-throughput designs. This limitation can be overcome by introducing a hardware element to the software radio platform. Enhancing GNU Radio for Hardware Accelerated Radio Design project implements suc...

  13. The coexistence of cognitive radio and radio astronomy

    NARCIS (Netherlands)

    Bentum, Marinus Jan; Boonstra, A.J.; Baan, W.A.

    2009-01-01

    An increase of the efficiency of spectrum usage requires the development of new communication techniques. Cognitive radio may be one of those new technique, which uses unoccupied frequency bands for communications. This will lead to more power in the bands and therefore an increasing level of Radio

  14. The coexistence of cognitive radio and radio astronomy

    NARCIS (Netherlands)

    Bentum, M.J.; Boonstra, A.J.; Baan, W.A.

    2009-01-01

    An increase of the efficiency of spectrum usage requires the development of new communication techniques. Cognitive radio may be one of those new technique, which uses unoccupied frequency bands for communications. This will lead to more power in the bands and therefore an increasing level of Radio

  15. Improving the throughput of cognitive radio networks using the broadcast approach

    KAUST Repository

    Sboui, Lokman

    2013-12-01

    We study the impact of adopting a multi layer coding (MLC) strategy, i.e., the so-called broadcast approach (BA) on the throughput of Cognitive Radio (CR) spectrum sharing systems for general fading channels. First, we consider a scenario where the secondary transmitter, a part from the statistics, has no channel state information (CSI) of the cross link and its own link. We show that using BA improves the cognitive achievable rate compared to the outage rate provided by a single layer coding (SLC). In addition, we, also, observe numerically that 2-Layer coding achieves most of the gain. Then, we consider a situation where the secondary transmitter has a partial CSI about its own link through quantized CSI. Again, we compute the secondary achievable rate adopting the BA and highlight the improvement over SLC. Numerical results show that the advantage of MLC decreases as the rate of the feedback link increases. 1 © 2013 IEEE.

  16. Optimal Spectrum Sharing in MIMO Cognitive Radio Networks via Semidefinite Programming

    CERN Document Server

    Zhang, Ying Jun

    2010-01-01

    In this paper, we study the optimal secondary-link beamforming pattern that balances between the SU's throughput and the interference it causes to PUs in MIMO cognitive radio networks. In particular, we aim to maximize the throughput of the SU, while keeping the interference temperature at the primary receivers below a certain threshold. Unlike traditional MIMO systems, SUs may not have the luxury of knowing the channel state information (CSI) on the links to PUs. This presents a key challenge for a secondary transmitter to steer interference away from primary receivers. In this paper, we consider three scenarios, namely when the secondary transmitter has complete, partial, or no knowledge about the channels to the primary receivers. In particular, when complete CSI is not available, the interference-temperature constraints are to be satisfied with high probability, thus resulting in chance constraints that are typically hard to deal with. Our contribution is fourfold. First, by analyzing the distributional c...

  17. Interference Neutralization vs Clean Relaying in Cognitive Radio Networks with Secrecy

    Directory of Open Access Journals (Sweden)

    Pin-Hsun Lin

    2015-08-01

    Full Text Available In this paper we study cognitive radio networks with secrecy constraints on the primary transmission. In particular we consider several transmission schemes for the secondary transmitter, namely interference neutralization (IN and cooperative jamming with and without clean relaying (CR. We derive and analyze the achievable secondary rate performance of the schemes. Furthermore we thoroughly investigate the advantages and shortcomings of these schemes through numerical simulations in a geometric model where we highlight the impact of the users’ locations and show the important difference in all schemes depending on the topology. Our results show that the secondary transmitter can successfully adapt its transmission scheme (and parameters, i.e., either IN or CR, depending on its location to maximize its rate while insuring perfect secrecy of the primary transmission.

  18. 2-Micron Laser Transmitter for Coherent CO2 DIAL Measurement

    Science.gov (United States)

    Singh, Upendra N.; Bai, Yingxin; Yu, Jirong

    2009-01-01

    Carbon dioxide (CO2) has been recognized as one of the most important greenhouse gases. It is essential for the study of global warming to accurately measure the CO2 concentration in the atmosphere and continuously record its variation. A high repetition rate, highly efficient, Q-switched 2-micron laser system as the transmitter of a coherent differential absorption lidar for CO2 measurement has been developed in NASA Langley Research Center. This laser system is capable of making a vertical profiling of CO2 from ground and column measurement of CO2 from air and space-borne platform. The transmitter is a master-slave laser system. The master laser operates in a single frequency, either on-line or off-line of a selected CO2 absorption line. The slave laser is a Q-switched ring-cavity Ho:YLF laser which is pumped by a Tm:fiber laser. The repetition rate can be adjusted from a few hundred Hz to 10 kHz. The injection seeding success rate is from 99.4% to 99.95%. For 1 kHz operation, the output pulse energy is 5.5mJ with the pulse length of 50 ns. The optical-to-optical efficiency is 39% when the pump power is 14.5W. A Ho:YLF laser operating in the range of 2.05 micrometers can be tuned over several characteristic lines of CO2 absorption. Experimentally, a diode pumped Ho:Tm:YLF laser has been successfully used as the transmitter of coherent differential absorption lidar for the measurement of CO2 with a repetition rate of 5 Hz and pulse energy of 75 mJ. For coherent detection, high repetition rate is required for speckle averaging to obtain highly precise measurements. However, a diode pumped Ho:Tm:YLF laser can not operate in high repetition rate due to the large heat loading and up-conversion. A Tm:fiber laser pumped Ho:YLF laser with low heat loading can operate in high repetition rate. A theoretical model has been established to simulate the performance of Tm:fiber laser pumped Ho:YLF lasers. For continuous wave (CW) operation, high pump intensity with small beam

  19. Primary user localisation and uplink resource allocation in orthogonal frequency division multiple access cognitive radio systems

    KAUST Repository

    Nam, Haewoon

    2015-05-21

    In cognitive radio networks, secondary users (SUs) can share spectrum with primary users (PUs) under the condition that no interference is caused to the PUs. To evaluate the interference imposed to the PUs, the cognitive systems discussed in the literature usually assume that the channel state information (CSI) of the link from a secondary transmitter to a primary receiver (interference link) is known at the secondary transmitter. However, this assumption may often be impractical in cognitive radio systems, since the PUs need to be oblivious to the presence of the SUs. The authors first discuss PU localisation and then introduce an uplink resource allocation algorithm for orthogonal frequency division multiple access-based cognitive radio systems, where relative location information between primary and SUs is used instead of CSI of the interference link to estimate the interference. Numerical and simulation results show that it is indeed effective to use location information as a part of resource allocation and thus a near-optimal capacity is achieved. © The Institution of Engineering and Technology 2015.

  20. Radio Quiet AGN

    CERN Document Server

    Czerny, B; Karas, V; Ponti, G

    2005-01-01

    Active Galactic Nuclei are powered by accretion onto massive black holes. Although radio-quiet objects are not as spectacular sources of very high energy photons as radio-loud ones this class of objects also represents a challenge for modeling high energy processes close to a black hole. Both a hot optically thin plasma and a cooler optically thick accretion disk are usually thought to be present in the vicinity of a black hole although the details of the accretion flow are still under discussion. The role of the disk seems to decrease with a drop in the Eddington ratio: in sources like quasars and Narrow Line Seyfert 1 galaxies disk flow dominates while in Seyfert galaxies the disk retreats, and in sources like LINERS or Sgr A* a disk is most likely absent. Shocks and reconnections are possibly taking place in an inner hot flow and in the magnetic corona above the cold disk. Uncollimated outflow is also present and it may carry significant fraction of available mass and energy.

  1. Radio astronomy from space

    Science.gov (United States)

    Woan, G.

    2011-04-01

    At frequencies below about 30 MHz, radio astronomy becomes increasingly difficult from the Earth's surface, mainly due to a combination of poor ionospheric seeing and strong terrestrial interference. The obvious move is to space, either as free-flying spacecraft or with a telescope located somewhere on the Moon. All the major space agencies have a renewed interest in the Moon as a site for exploration and science, and low-frequency radio astronomy is probably the strongest of the astronomical objectives put forward in these programmes. Although the Sun is a strong source of interference in extra-solar system work, it is also a prime target for study in itself. A constellation of satellites (as proposed for the SIRA mission) would be able to image both the Sun and the inner heliosphere over the entire low-frequency band. Here we investigate some of the advantages and limitations of astronomy at these very low frequencies, using space- and lunar-based antennas.

  2. On Using Solar Radio Emission to Probe Interiors of Asteroids and Comets

    Science.gov (United States)

    Winebrenner, D. P.; Gary, D. E.; Sahr, J. D.; Asphaug, E. I.

    2015-12-01

    Asteroids, comets and other primitive solar system bodies are key sources of information on the early solar system, on volatiles and organics delivered to the terrestrial planets, and on processes of planetary formation now observed in operation around other stars. Whether asteroids (in various size classes) are rubble piles or monolithic, and whether any porosity or internal voids contain volatiles, are first-order questions for understanding the delivery of volatiles to the early Earth, and for assessing impact hazards. Information on bulk composition aids discrimination between types and origins of primitive bodies, .e.g., the degree of aqueous alteration and bound-water content of carbonaceous chondrite bodies, and the volatile mass fraction of comets. Radar and radio methods can provide direct information on bulk composition, micro- and macro-porosity, body-scale internal structure, and on whether voids in rocky materials are volatile- or vacuum-filled. Such methods therefore figure prominently in current missions to primitive bodies (e.g., CONSERT) and in a variety of proposed missions. Radio transmitters necessary for conventional methods, however, add considerably to spacecraft mass and power requirements. Moreover, at many wavelengths most useful for radio sounding, powerful radio emission from the Sun strongly interferes with conventional signals. Here we present initial results from an investigation of how solar radio emission could serve as a natural resource for probing interiors of primitive bodies, rather than as interference. We briefly review methods for using stochastic radio illumination (aka noise radar methods), and illustrate the characteristics of solar radio emission relevant to mission design (e.g., observed intervals between emission events of specified intensity for different points in the solar cycle). We then discuss methods for selecting and interpreting observations in terms of interior properties, for bodies is different size classes

  3. 78 FR 32165 - Commercial Radio Operators; Correction

    Science.gov (United States)

    2013-05-29

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

  4. Radio Relics in Cosmological Simulations

    Indian Academy of Sciences (India)

    M. Hoeft; S. E. Nuza; S. Gottlöber; R. J. van Weeren; H. J. A. Röttgering; M. Brüggen

    2011-12-01

    Radio relics have been discovered in many galaxy clusters. They are believed to trace shock fronts induced by cluster mergers. Cosmological simulations allow us to study merger shocks in detail since the intra-cluster medium is heated by shock dissipation. Using high resolution cosmological simulations, identifying shock fronts and applying a parametric model for the radio emission allows us to simulate the formation of radio relics. We analyze a simulated shock front in detail. We find a rather broad Mach number distribution. The Mach number affects strongly the number density of relativistic electrons in the downstream area, hence, the radio luminosity varies significantly across the shock surface. The abundance of radio relics can be modeled with the help of the radio power probability distribution which aims at predicting radio relic number counts. Since the actual electron acceleration efficiency is not known, predictions for the number counts need to be normalized by the observed number of radio relics. For the characteristics of upcoming low frequency surveys we find that about thousand relics are awaiting discovery.

  5. Tuning in to pavement radio

    NARCIS (Netherlands)

    Ellis, S.D.K.

    1989-01-01

    This article describes a phenomenon known all over Africa, for which there is no really satisfactory term in English but which is summed up in the French term 'radio trottoir', literally 'pavement radio'. It may be defined as the popular and unofficial discussion of current affairs in Africa,

  6. Cognitive Radio for Emergency Networks

    NARCIS (Netherlands)

    Zhang, Q.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

    2006-01-01

    In the scope of the Adaptive Ad-hoc Freeband (AAF) project, an emergency network built on top of Cognitive Radio is proposed to alleviate the spectrum shortage problem which is the major limitation for emergency networks. Cognitive Radio has been proposed as a promising technology to solve todayâ?~B

  7. Radio Loud AGNs are Mergers

    CERN Document Server

    Chiaberge, Marco; Lotz, Jennifer; Norman, Colin

    2015-01-01

    We measure the merger fraction of Type 2 radio-loud and radio-quiet active galactic nuclei at z>1 using new samples. The objects have HST images taken with WFC3 in the IR channel. These samples are compared to the 3CR sample of radio galaxies at z>1 and to a sample of non-active galaxies. We also consider lower redshift radio galaxies with HST observations and previous generation instruments (NICMOS and WFPC2). The full sample spans an unprecedented range in both redshift and AGN luminosity. We perform statistical tests to determine whether the different samples are differently associated with mergers. We find that all (92%) radio-loud galaxies at z>1 are associated with recent or ongoing merger events. Among the radio-loud population there is no evidence for any dependence of the merger fraction on either redshift or AGN power. For the matched radio-quiet samples, only 38% are merging systems. The merger fraction for the sample of non-active galaxies at z>1 is indistinguishable from radio-quiet objects. This...

  8. Relics of Double Radio Sources

    CERN Document Server

    Dwarakanath, K S

    2009-01-01

    We have formed a new sample which consists of extended extragalactic radio sources without obvious active galactic nuclei (AGN) in them. Most of these sources appear to be dead double radio sources. These sources with steep spectra ($\\alpha < $ -1.8; S $\\propto \

  9. Cognitive Radio for Emergency Networks

    NARCIS (Netherlands)

    Zhang, Qiwei; Kokkeler, A.B.J.; Smit, G.J.M.

    2006-01-01

    In the scope of the Adaptive Ad-hoc Freeband (AAF) project, an emergency network built on top of Cognitive Radio is proposed to alleviate the spectrum shortage problem which is the major limitation for emergency networks. Cognitive Radio has been proposed as a promising technology to solve todayâ?~B

  10. The Radio Phenomenon in Italy.

    Science.gov (United States)

    Faenza, Roberto

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

  11. Solar active envelope module with an adjustable transmittance/absorptance

    Directory of Open Access Journals (Sweden)

    C. Villasante Villasante

    2015-06-01

    Full Text Available A solar active envelope module with a high flexibility degree is proposed in this paper. The transparent module controls the day-lighting of the room, improving the indoor environment, while absorbing the superfluous solar energy inside. That energy is used to increase the efficiency of heating, ventilation, and the air-conditioning (HVAC system of the building. This is carried out through a fine control of the absorptance of the envelope module. The active envelope module consists of three glazed chambers with advanced coatings and frames to assure a minimum thermal transmittance while allowing transparency. A fluid containing heat-absorbing nanoparticles flows inside the central chamber and is heated up due to the impinging solar energy. Unlike other systems proposed in the past, which included transparency control systems based on complex filters and chemical processes, the absorption of the module is controlled by the variation of the thickness of the central chamber with a mechanical device. That is, varying the thickness of the central chamber, it allows controlling the absorptance of the whole system and, as a result, indoor day-lighting and thermal loads. Therefore, a new system is proposed that enables to:  

  12. Computational Investigations of THz Transmittance in the Atmosphere

    Science.gov (United States)

    Yang, Xingyu; Calhoun, Casey; Calhoun, Ronald

    2016-06-01

    With the recent scientific advancements in Terahertz (THz) wave propagation and reception technology, there has been significant development in new possibilities for using THz waves - offering new possibilities in THz detection and ranging. A first foundational step toward this goal is to better understand THz transmittance in the turbulent atmosphere. In this project, a frequency modulation pattern of THz waves was created by utilizing a system of shifting frequency based on temperature, air humidity, and distance of transmission. The total path loss of the wave in air, based on the wave spread and molecular absorption, was then modeled using radiative transfer theory, onto a set of JavaHAWK filtered-HITRAN data representative of an air sample. This data was used to generate a path loss matrix, which was then used to optimize frequency of transmission for the specific conditions. The concept to be evaluated is whether adaptive frequency modulated THz might usefully decrease transmission losses by adjusting to atmospheric conditions (such as local variations in temperature and humidity).

  13. Gas detection by using transmittance estimation and segmentation approaches

    Science.gov (United States)

    Özısık Baskurt, Didem; Gür, Yusuf; Ömrüuzun, Fatih; ćetin, Yasemin Yardımcı

    2016-10-01

    Hyperspectral imaging for gas detection applications is an under-researched topic. The same gas model is used in most of the gas detection studies in the literature. This model aims to formulate the scene covering the gas emission as well as the background and the atmosphere. Therefore, the model requires prior knowledge on transmittance, emissivity, and temperature values of the components in the scene. The commonly used approaches to estimate these parameters include atmospheric modeling and statistical inference. However, accessing such information is costly in remote detection applications. Some studies avoid background characterization by decomposing the scene using spectral-spatial information. There are several studies in the literature using this model. They aim to detect various types of gases on different parts of electromagnetic spectrum. Most of these studies use hyperspectral radiance information regarding the scene. However, using brightness temperature map of the data instead of radiance data is more suitable for direct analysis. For this reason, we used brightness temperature spectrum in this study. On the other hand, the detection algorithms are generally based on pixel based investigation. Since the emission of the gas is sourced by a pipe or a chimney, investigating the emission region at the segment level increases detection accuracy. In this study, we used an iterative spectral feature based pixel clustering algorithm followed by spatial segmentation.

  14. When a pressure transmitter leaves the linearity: The Rosemount case

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez, J. [Department of Nuclear Fission, CIEMAT, 22 Complutense Av., 28040 Madrid (Spain)]. E-mail: juan.blazquez@ciemat.es

    2006-07-01

    When a Rosemount pressure transmitter experiences the inner silicone oil-loss syndrome, it loses its linear behaviour. In such a case, the response time is not unique; as a consequence, focusing the sensor surveillance to the response time, as required by the technical specifications of the nuclear plant, might have no sense. In which way is the sensor dynamic not linear? Answering this open question is the main objective of this work. A bilinear model can explain most of the features of the noise signal. A more elaborated model is built in order to explain the results of the deterministic experiments. The corresponding non-linear differential equation is solved exactly for the step response, and an approximate expression is found for the anomalous response time. When the driving term of the dynamic is not a step, the differential equation is solved approximately using the Picard iteration procedure. It gives some light on why the oscillations lose symmetry or why the amplitude probability of the noise signal shows skewness. (author)

  15. Designing Parallel Bus Using Universal Asynchronous Receiver Transmitter

    Directory of Open Access Journals (Sweden)

    Satyandra Sharad

    2013-04-01

    Full Text Available This paper entitled “DESIGNING PARALLEL BUSUSING UNIVERSAL ASYNCHRONOUS RECEIVER TRANSMITTER” is designed to the core of a UART interface module, which includes both receive and transmit modules, and the command parser. This paper will be a viable solution to design parallel buses with the help of UART. In the test bench , there is a RFM(register file model to which we write/read back data from just to check our design .The txt file issues serial inputs to the core and the core outputs parallel data and address in the form of bus. This bus is connected to our RFM (register file model instantiated in the test bench along with the design. This makes easy to retrieve parallel data from serial input. The base of the paper is to use microcontroller along with other components to interface with the physical world. In contrast, most serial communication must first be converted back into parallel form by a universal asynchronous receiver/transmitter (UART before they may be directly connected to a data bus. Both Transmissions (Parallel and Serial are used to connect peripheral devices and enable us to communicate with these devices. The UART core described here is designed using VHDL and implemented on Xilinx Vertex FPGA.

  16. Wavelength-agile integrated optical transmitters for analog applications

    Science.gov (United States)

    Johansson, Leif A.; Chen, Chin-Hui; Akulova, Yuliya A.; Fish, Gregory A.; Coldren, Larry A.

    2003-12-01

    A summary of current work involving the development of high performance, wavelength-tunable integrated optical transmitters for analog applications is given. The performance of sampled-grating DBR lasers integrated with an SOA and an electroabsorption or Mach-Zehnder modulator is evaluated in terms of E/O conversion efficiency, noise performance and dynamic range. Optimization options to maximize either gain, noise figure or spurious-free dynamic range in analog link applications are discussed. It is shown how the combination of chip-scale integration and the use of bulk waveguide Franz-Keldysh absorption allows coupling of a large optical power level into the electroabsorption modulator, and its effects on the modulation response and analog link performance. Link results on an integrated SGDBR-SOA-EAM device includes a sub-octave SFDR in the 125 to 127 dB/Hz4/5 range and a broadband SFDR of 103-107 dB/Hz2/3 limited by third order intermodulation products or 95-98 dB/Hz1/2, limited by second order intermodulation products, over a 1528 to 1573 nm wavelength range.

  17. DESIGN AND DEVELOPMENT OF XBAND OSCILLATOR FOR FM TELEMETRY TRANSMITTER

    Directory of Open Access Journals (Sweden)

    S.SREEKANTH,

    2011-05-01

    Full Text Available Oscillator represents the basic microwave energy source for all microwave systems such as radar, communication and navigation. A typical oscillator essentially consist of an active device and passivefrequency determining resonant element such as dielectric resonator, micro strip resonator and tuned circuit for fixed frequency oscillators, varactor for tunable oscillators. The transistor used was fujitsu, FHX13LG, operating at DC bias of 2V and 25mA.The oscillator was designed using the 1/3 oscillation rule because of its effectiveness and simplicity. Oscillator feedback was connected to HEMT in a common source configuration using transmission line and capacitor. The emphasis has been on high power, low noise, small cost, high reliability and high temperature stability.Practical design aspects including the choice of transistor, negative feedback circuits, load coupling, low phase noise, quality factor and operation at the highest phase slope for minimum phase noise areincluded. This paper deals Design and Development of X band Oscillator for Telemetry Transmitter by using ADS simulation software and it has been designed at 8 GHz frequency.

  18. Computational Investigations of THz Transmittance in the Atmosphere

    Directory of Open Access Journals (Sweden)

    Yang Xingyu

    2016-01-01

    Full Text Available With the recent scientific advancements in Terahertz (THz wave propagation and reception technology, there has been significant development in new possibilities for using THz waves – offering new possibilities in THz detection and ranging. A first foundational step toward this goal is to better understand THz transmittance in the turbulent atmosphere. In this project, a frequency modulation pattern of THz waves was created by utilizing a system of shifting frequency based on temperature, air humidity, and distance of transmission. The total path loss of the wave in air, based on the wave spread and molecular absorption, was then modeled using radiative transfer theory, onto a set of JavaHAWK filtered-HITRAN data representative of an air sample. This data was used to generate a path loss matrix, which was then used to optimize frequency of transmission for the specific conditions. The concept to be evaluated is whether adaptive frequency modulated THz might usefully decrease transmission losses by adjusting to atmospheric conditions (such as local variations in temperature and humidity.

  19. Radio outburst of BL Lacertae

    Science.gov (United States)

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

    2013-04-01

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

  20. Radio Emission from Globular Clusters

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Radio emission of globular clusters is studied by analyzing the VLA radio survey data of the NVSS and FIRST. We find that 13 clusters have radio sources within their half-mass radii of clusters. Sources detected previously in NGC 7078and NGC 6440 are identified. Pulsars in NGC 6121, NGC 6440 and NGC 7078cannot be detected because of the insufficient survey sensitivity and resolution.There may be a pulsar in the core of Terzan 1. The nature of the extended radio source near the core of NGC 6440 remains unclear. In the core of a globular cluster,there may be many neutron stars or an intermediate mass black hole, but this cannot be clarified with the current radio observations.

  1. CONSTRAINING RADIO EMISSION FROM MAGNETARS

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, P.; Kaspi, V. M.; Dib, R. [Department of Physics, Rutherford Physics Building, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Champion, D. J. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Hessels, J. W. T., E-mail: plazar@physics.mcgill.ca [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands)

    2012-01-10

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U 0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected for any of our targets. The non-detections allow us to place luminosity upper limits of L{sub 1950} {approx}< 1.60 mJy kpc{sup 2} for periodic emission and L{sub 1950,single} {approx}< 7.6 Jy kpc{sup 2} for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.

  2. Constraining Radio Emission from Magnetars

    CERN Document Server

    Lazarus, Patrick; Champion, David J; Hessels, Jason W T; Dib, Rim

    2011-01-01

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected was detected for any of our targets. The non-detections allow us to place luminosity upper limits (at 1950 MHz) of approximately L < 1.60 mJy kpc^2 for periodic emission and L < 7.6 Jy kpc^2 for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.

  3. Radio propagation measurement and channel modelling

    CERN Document Server

    Salous, Sana

    2013-01-01

    While there are numerous books describing modern wireless communication systems that contain overviews of radio propagation and radio channel modelling, there are none that contain detailed information on the design, implementation and calibration of radio channel measurement equipment, the planning of experiments and the in depth analysis of measured data. The book would begin with an explanation of the fundamentals of radio wave propagation and progress through a series of topics, including the measurement of radio channel characteristics, radio channel sounders, measurement strategies

  4. CURIE: Cubesat Radio Interferometry Experiment

    Science.gov (United States)

    Sundkvist, D. J.; Saint-Hilaire, P.; Bain, H. M.; Bale, S. D.; Bonnell, J. W.; Hurford, G. J.; Maruca, B.; Martinez Oliveros, J. C.; Pulupa, M.

    2016-12-01

    The CUbesat Radio Interferometry Experiment (CURIE) is a proposed two-element radio interferometer, based on proven and developed digital radio receivers and designed to fit within a Cubesat platform. CURIE will launch as a 6U Cubesat and then separate into two 3U Cubesats once in orbit. CURIE measures radio waves from 0.1-19MHz, which must be measured from space, as those frequencies fall below the cutoff imposed by Earth's ionosphere. The principal science objective for CURIE is to use radio interferometry to study radio burst emissions from solar eruptive events such as flares and coronal mass ejections (CMEs) in the inner heliosphere, providing observations important for our understanding of the heliospheric space weather environment. The influence of space weather can be felt at Earth and other planets, as radiation levels increase and lead to auroral activity and geomagnetic effects. CURIE will be able to determine the location and size of radio burst source regions and then to track their movement outward from the Sun. In addition to the primary objective CURIE will measure the gradients of the local ionospheric density and electron temperature on the spatial scale of a few kilometers, as well as create an improved map of the radio sky at these unexplored frequencies. A space based radio interferometry observatory has long been envisioned, in orbit around the Earth or the Moon, or on the far side of the Moon. Beyond its important science objectives, CURIE will prove that the concept of a dedicated space-based interferometer can be realized by using relatively cheap Cubesats. CURIE will therefore not only provide new important science results but also serve as a pathfinder in the development of new space-based radio observation techniques for helio- and astro-physics.

  5. The faint radio sky: radio astronomy becomes mainstream

    Science.gov (United States)

    Padovani, Paolo

    2016-09-01

    Radio astronomy has changed. For years it studied relatively rare sources, which emit mostly non-thermal radiation across the entire electromagnetic spectrum, i.e. radio quasars and radio galaxies. Now, it is reaching such faint flux densities that it detects mainly star-forming galaxies and the more common radio-quiet active galactic nuclei. These sources make up the bulk of the extragalactic sky, which has been studied for decades in the infrared, optical, and X-ray bands. I follow the transformation of radio astronomy by reviewing the main components of the radio sky at the bright and faint ends, the issue of their proper classification, their number counts, luminosity functions, and evolution. The overall "big picture" astrophysical implications of these results, and their relevance for a number of hot topics in extragalactic astronomy, are also discussed. The future prospects of the faint radio sky are very bright, as we will soon be flooded with survey data. This review should be useful to all extragalactic astronomers, irrespective of their favourite electromagnetic band(s), and even stellar astronomers might find it somewhat gratifying.

  6. A Radio Astronomy Science Education Partnership - GAVRT and Radio JOVE

    Science.gov (United States)

    Higgins, C. A.; Thieman, J. R.; Bunnell, K.; Soholt, G.

    2009-12-01

    The planet Jupiter provides an excellent subject to educate, engage, and inspire students and teachers to learn science. The Goldstone Apple-Valley Radio Telescope (GAVRT) program (http://www.lewiscenter.org/gavrt) and The Radio JOVE project (http://radiojove.gsfc.nasa.gov) each have a long history of allowing students and teachers to interact with scientists and real radio telescopes. The upcoming Juno mission to Jupiter (2011 launch) allows both GAVRT and Radio JOVE to combine efforts and engage with the NASA Juno mission, thus increasing the excitement and learning potential for teachers, students, and the general public. Teachers can attend workshops for training to operate a 34-meter radio telescope and/or build their own simple radio telescope, both of which can be used directly in the classroom. We will overview some classroom activities and highlight some teacher-student experiences. In addition, we will update our efforts on greater Web-based control of the radio telescopes, as well as highlight our upcoming workshops to allow better access for teachers in different parts of the Country.

  7. The faint radio sky: radio astronomy becomes mainstream

    CERN Document Server

    Padovani, Paolo

    2016-01-01

    Radio astronomy has changed. For years it studied relatively rare sources, which emit mostly non-thermal radiation across the entire electromagnetic spectrum, i.e. radio quasars and radio galaxies. Now it is reaching such faint flux densities that it detects mainly star-forming galaxies and the more common radio-quiet active galactic nuclei. These sources make up the bulk of the extragalactic sky, which has been studied for decades in the infrared, optical, and X-ray bands. I follow the transformation of radio astronomy by reviewing the main components of the radio sky at the bright and faint ends, the issue of their proper classification, their number counts, luminosity functions, and evolution. The overall "big picture" astrophysical implications of these results, and their relevance for a number of hot topics in extragalactic astronomy, are also discussed. The future prospects of the faint radio sky are very bright, as we will soon be flooded with survey data. This review should be useful to all extragalac...

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

    Science.gov (United States)

    Christensen, P R

    1985-01-01

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

  9. Implementing Software Defined Radio

    CERN Document Server

    Grayver, Eugene

    2013-01-01

    Software Defined Radio makes wireless communications easier, more efficient, and more reliable. This book bridges the gap between academic research and practical implementation. When beginning a project, practicing engineers, technical managers, and graduate students can save countless hours by considering the concepts presented in these pages. The author covers the myriad options and trade-offs available when selecting an appropriate hardware architecture. As demonstrated here, the choice between hardware- and software-centric architecture can mean the difference between meeting an aggressive schedule and bogging down in endless design iterations. Because of the author’s experience overseeing dozens of failed and successful developments, he is able to present many real-life examples. Some of the key concepts covered are: Choosing the right architecture for the market – laboratory, military, or commercial Hardware platforms – FPGAs, GPPs, specialized and hybrid devices Standardization efforts to ens...

  10. MUSIC RADIO-JOURNALISM

    Directory of Open Access Journals (Sweden)

    Dubovtceva Ludmila I.

    2014-04-01

    Full Text Available The article is based on years of practical experience, the author highlights the main radio genres in which music correspondent, music reviewer, music commentator, and music leading and a disc jockey work. Theoretical principles of their creative activities are analyzed in common journalistic genres, such as interview, reportage, talk show, live broadcast, radiofilm, as well as specialized genres like concert on demand and music competition. Journalist’ speech is seen as a logical element, the incoming with music in art-structural relationships. However, it does not become the predominant sound layer and aims to harmonious correlation or local penetration into music opus. In addition, important links in music journalism are defined the auxiliary "offscreen" editor's job and keeping the original sound archive. The author cites a number of own work examples on the air.

  11. Teaching radio astronomy with Affordable Small Radio Telescope (ASRT)

    Science.gov (United States)

    Joshi, Bhal Chandra

    A simple, easy to build and portable radio telescope, called Affordable Small Radio Telescope (ASRT), has been developed by the Radio Physics Laboratory (RPL), a radio astronomy teaching unit associated with the National Centre for Radio Astrophysics (TIFR) and Inter-University Centre for Astronomy and Astrophysics (IUCAA), which are two premier astronomy institutes in India. ASRT consists of off-the-shelf available Direct to Home television dishes and is easy to assemble. Our design is scalable from simple very low cost telescope to more complex yet moderately costing instrument. ASRT provides a platform for demonstrating radio physics concepts through simple hands-on experiment as well as for carrying out solar monitoring by college/University students. The presentation will highlight the concept of ASRT and the different experiments that can be carried out using it. The solar monitoring observations will be discussed along-with details of methods for calibrating these measurements. The pedagogical usefulness of ASRT in introducing undergraduatephysics students to astrophysics, measurements and analysis methods used in radio astronomy will also be discussed. Use of ASRT in the last three years in the programs of RPL, namely the annual Radio Astronomy Winter School for College students (RAWSC) and Pulsar Observing for Students (POS) is also presented. This year a new program was initiated to form a virtual group of an ASRT community, which will not only share their measurements, but also think of improving the pedagogical usefulness of ASRT by innovative experiments. This initiative is presented with the best practices drawn from our experience in using ASRT as a tool for student training in space sciences. The talk will also point out future ideas in involving a larger body of students in simple radio astronomy experiments with the ASRT, which RPL is likely to nucleate as part of its mandate.

  12. South African Radio League Introduction to Amateur Radio: A study guide for the Radio Amateur Examination

    CSIR Research Space (South Africa)

    Burger, Chris

    2016-01-01

    Full Text Available recognition of amateur radio licences. South African radio amateurs can exercise their privileges in more than 80 countries and territories with minimal paperwork. In exchange, we have an obligation to ensure that all licence holders possess a minimum level...

  13. On the Optimality of Opportunistic Interference Alignment in 3-Transmitter MIMO Interference Channels

    CERN Document Server

    Lee, Jung Hoon; Love, David J

    2011-01-01

    In this paper, we propose opportunistic interference alignment (OIA) for three-transmitter multiple-input multiple-output (MIMO) interference channels (ICs). In the proposed OIA scheme, each transmitter has its own user group that consists of $K$ users, and each transmitter opportunistically selects the user whose received interference signals are most aligned. Thus, three-transmitter MIMO IC is opportunistically constructed by three transmitters and their selected users. Contrary to conventional IA, perfect channel information for all of the interference links is not required at the transmitter. Each user just needs to feed back one scalar value in the proposed OIA scheme. When the number of receive antennas is $N_R$ (with $N_R=2M$) and the number of transmit antennas is $N_T$ (with $N_T\\ge M$), we prove that each transmitter can achieve $M$ degrees of freedom (DoF) as the number of users in each group goes to infinity ($K\\to\\infty$), in comparison with the $\\frac{2M}{3}$ DoF known to be achievable in the th...

  14. A New CO2 Transmittance Parameterization and Its Impact on the GLA GCM

    Science.gov (United States)

    Wobus, R.; Wui, M. L. C.; Susskind, J.

    1985-01-01

    The Wu-Kaplan radiation parameterization (Krishnamurthy, 1982) used in the GLA Global Circulation Model (GCM) was improved by replacing its fixed tables of CO2 transmittance in the 15 micron band with models developed by regression on line-by-line transmittances. The transmittances between layers are modeled as products of effective sublayer transmittances. The GLA GCM was integrated for 20 days starting at OZ, January 21, 1979, using the transmittance model. In the control run the fixed table of 15 micron CO2 transmittances is used. The effect of the change of initial cooling rate is illustrated by a map of the difference of 50 mb temperature after 6 hours. The cooling is reduced over high topography, where the fixed table underestimates the transmittance, and is reduced slightly throughout the tropics and the north polar area where the stratosphere is relatively cold. Over elevated topography the surface cooling increases, also as expected. The stratospheric temperature increases over a degree in the arctic and smaller amounts over Antarctica and elsewhere. Tropospheric equilibrium temperature response is obscured by time dependent differences in synoptic disturbances.

  15. The timing of phasic transmitter release is Ca2+-dependent and lacks a direct influence of presynaptic membrane potential

    OpenAIRE

    Felmy, Felix; Neher, Erwin; Schneggenburger, Ralf

    2003-01-01

    Ca2+ influx through voltage-gated Ca2+ channels and the resulting elevation of intracellular Ca2+ concentration, [Ca2+]i, triggers transmitter release in nerve terminals. However, it is controversial whether in addition to the opening of Ca2+ channels, membrane potential directly affects transmitter release. Here, we assayed the influence of membrane potential on transmitter release at the calyx of Held nerve terminals. Transmitter release was evoked by presynaptic Ca2+ uncaging, or by presyn...

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

    Science.gov (United States)

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

    1973-01-01

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

  17. Ionospheric Modification by High Power, Obliquely Propagated HF Radio Wave Transmissions. Part 1. Experimental

    Science.gov (United States)

    1993-07-01

    frequency of the disturbing transmitter is greater than the i.. asma frequency in the ionospheric interaction region. In fact, with many practical radio...NY) lay in the Gulf of Mexico and it was not possible to use an oblique probe system similar to- the technique used by the Soviets in their...using a vertical incidence sounder at Albuquerque, New Mexico (35.11N, 106.8 0W) at the midpoint of the 2400 km path. This technique insures that the

  18. ADAPTIVE MODULATION AND POWER CONTROL FOR THROUGHPUT ENHANCEMENT IN COGNITIVE RADIOS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To regulate the transmit-power and enhance the total throughput, a novel Transmit Power Control Game (TPCG) algorithm and an adaptive Modulation TPCG (M-TPCG) algorithm which combine bandwidth allocation, adaptive modulation and transmit-power control based on Space Time Block Coding (STBC) OFDM-CDMA system are designed and a cross-layer framework of database sharing is proposed. Simulation results show that the TPCG algorithm can regulate their transmitter powers and enhance the total throughput effectively, M-TPCG algorithm can achieve maximal system throughput. The performance of the cognitive radio system is improved obviously.

  19. Rayleigh beacon for measuring the surface profile of a radio telescope.

    Science.gov (United States)

    Padin, S

    2014-12-01

    Millimeter-wavelength Rayleigh scattering from water droplets in a cloud is proposed as a means of generating a bright beacon for measuring the surface profile of a radio telescope. A λ=3  mm transmitter, with an output power of a few watts, illuminating a stratiform cloud, can generate a beacon with the same flux as Mars in 10 GHz bandwidth, but the beacon has a narrow line width, so it is extremely bright. The key advantage of the beacon is that it can be used at any time, and positioned anywhere in the sky, as long as there are clouds.

  20. Outage Probability of SINR for Underlay Cognitive Radio Systems in Nakagami Fading

    Science.gov (United States)

    Jarrouj, Jiana; Blagojevic, Vesna; Ivanis, Predrag

    2014-11-01

    In this paper underlay cognitive radio system is analyzed in Nakagami fading environment, for the case when the available channel state information (CSI) of the link from the secondary transmitter to the primary receiver is outdated. We considered the case when both interference and transmit power constraints are applied. The impact of the co-channel interference that originates from the primary user is analyzed in details. The exact closed-form expressions for probability density function, outage probability, and the moments of signal-to-interference and noise ratio (SINR) at the secondary user's receiver are derived. The analytical expressions are verified by using independent Monte Carlo simulation method.

  1. Design and implementation of an error-compensating subreflector for the NRAO 12-m radio telescope.

    Science.gov (United States)

    Mayer, C. E.; Emerson, D. T.; Davis, J. H.

    1994-05-01

    This paper describes the measurement of the surface shape of the primary reflector of the NRAO 12-m radio telescope and the use of the measurements to machine the shape of a secondary mirror to compensate for the primary reflector errors. The method known as holography was used with the 38.04-GHz transmitter onboard the geosynchronous Lincoln Experimental Satellite to map the main reflector. The machining of the secondary compensated for the errors in the primary shape, and as a result, at 345 GHz, the axial gain of the instrument was increased by about 50% and the antenna pattern correspondingly improved.

  2. 77 FR 41473 - Proposed Technical Standard Order (TSO)-C126b, 406 MHz Emergency Locator Transmitters (ELT) and...

    Science.gov (United States)

    2012-07-13

    ... ELT mounting. Advisory material discouraging the use of hook and loop fasteners includes the following... Transmitters (ELT) and Notice of Intent To Withdraw TSO Authorizations (TSOA) for TSO-C91a, Emergency Locator Transmitter (ELT) Equipment, and TSO-C126/C126a, 406 MHz Emergency Locator Transmitters (ELT) AGENCY:...

  3. Eight-wavelength distributed-Bragg-reflector (DBR) laser array transmitter for WDM applications

    Science.gov (United States)

    Fallahi, Mahmoud; McGreer, K. A.; Delage, Andre; Neophytou, A.; Templeton, Ian M.; Champion, Garth; Chatenoud, F.; Barber, Richard A.; Wang, Weijian; He, Jian Jun; Koteles, Emil S.

    1995-03-01

    We report on the design, growth, fabrication and characterization of monolithic wavelength division multiplexed (WDM) laser array transmitter and receiver chips produced by the Canadian Solid State Optoelectronics Consortium. The transmitter chip includes multiple, discrete wavelength, distributed Bragg reflector (DBR) laser diodes monolithically integrated with waveguide combiners fabricated using an InGaAs/GaAs heterostructure. The corresponding wavelength demultiplexer unit is based on a Rowland circle grating spectrometer monolithically integrated with a metal-semiconductor-metal (MSM) detector array fabricated on an InGaAs/AlGaAs/GaAs heterostructure. The epitaxial layer wafers for both transmitter and receiver modules were grown in single molecular beam epitaxy (MBE) runs.

  4. The Design of New-Type Smart Temperature Transmitter Based on Computer Networks

    Institute of Scientific and Technical Information of China (English)

    LING Zhen-bao; WANG Jun; QIU Chun-ling

    2004-01-01

    In this article, the functions and features of another generation of single-chip microcomputer MSP430 with low power consumption and high performance are introduced. Based on these,the method of designing the intelligent and miniaturized temperature transmitter is proposed. The design block diagram and software flowchart of circuit hardware of every part of the intelligent temperature transmitter are supplied. This transmitter has advantages like high cost-performance ratio, small size, strong noise resistance-good interchangeability, broad field of application,and it can also be used for measuring and transmitting the temperature in the control system.

  5. In-Flight Performance of the Mercury Laser Altimeter Laser Transmitter

    Science.gov (United States)

    Yu, Anthony W.; Sun, Xiaoli; Li, Steven X.; Cavanaugh, John F.; Neumann, Gregory A.

    2014-01-01

    The Mercury Laser Altimeter (MLA) is one of the payload instruments on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, which was launched on August 3, 2004. MLA maps Mercury's shape and topographic landforms and other surface characteristics using a diode-pumped solid-state laser transmitter and a silicon avalanche photodiode receiver that measures the round-trip time of individual laser pulses. The laser transmitter has been operating nominally during planetary flyby measurements and in orbit about Mercury since March 2011. In this paper, we review the MLA laser transmitter telemetry data and evaluate the performance of solid-state lasers under extended operation in a space environment.

  6. Marine spawning sites of perch Perca fluviatilis revealed by oviduct-inserted acoustic transmitters

    DEFF Research Database (Denmark)

    Skovrind, Mikkel; Christensen, Emil A.F.; Carl, Henrik

    2013-01-01

    a strong proof of concept of oviduct-inserted acoustic transmitters in brackish and marine fish spawning studies. The transmitter expulsions were validated using an egg map, which was based on visual observations of perch egg-strands, and 11 of the 12 expulsed transmitters (92%) were located in areas...... with eggs. Many fish spawned in the brackish water with salinities up to 9.6 PSU. These salinities are higher than those previously observed for European perch spawning in the wild, and call for further investigations of salinity tolerance in perch eggs...

  7. Determination of Aluminium Content in Aluminium Hydroxide Formulation by FT-NIR Transmittance Spectroscopy

    DEFF Research Database (Denmark)

    Lai, Xuxin; Zheng, Yiwu; Søndergaard, Ib

    2007-01-01

    A method for determining the aluminium content of an aluminium hydroxide suspension using near infrared (NIR) transmittance spectroscopy has been developed. Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) was used as reference method. The factors influencing the NIR analysis......-AES and NIR transmittance spectroscopy exhibit comparable precision and accuracy. The NIR method provides several advantages: no complicated sample preparation; easy to operate; fast and non-destructive. In conclusion, NIR transmittance spectroscopy can be an alternative analytical method for determining...

  8. Dust tori in radio galaxies

    CERN Document Server

    van der Wolk, G; Peletier, R F; Pel, J W

    2009-01-01

    We investigate the validity of the quasar - radio galaxy unification scenario and determine the presence of dust tori among radio galaxies of various types. Actively accreting supermassive black holes in the centres of radio galaxies may be uncovered through their dust tori reradiating the optical and ultraviolet continuum in mid-infrared bands. Using VISIR on the VLT, we have obtained sub-arcsecond (~0.40") resolution N-band images, at a wavelength of 11.85 micron, of the nuclei of a sample of 27 radio galaxies of four types in the redshift range z=0.006-0.156. The sample consists of 8 edge-darkened, low-power Fanaroff-Riley class I (FR-I) radio galaxies, 6 edge-brightened, class II (FR-II) radio galaxies displaying low-excitation optical emission, 7 FR-IIs displaying high-excitation optical emission, and 6 FR-II broad emission line radio galaxies. Out of the sample of 27 objects, 10 nuclei are detected and several have constraining non-detections at 10 sigma sensitivities of 7 mJy. On the basis of the core ...

  9. Two-way fiber-wireless convergence systems based on two-stage injection-locked VCSELs transmitter and optical interleaver.

    Science.gov (United States)

    Li, Chung-Yi; Lu, Hai-Han; Ying, Cheng-Ling; Zheng, Jun-Ren; Lin, Che-Yu; Wan, Zhi-Wei

    2015-02-23

    A two-way fiber-wireless convergence system based on a two-stage injection-locked 1.55-μm vertical-cavity surface-emitting lasers (VCSELs) transmitter and an optical interleaver (IL) to deliver intensity-modulated and phase-remodulated millimeter-wave (MMW) data signals over a 40-km single-mode fiber (SMF) and a 5-m radio frequency (RF) wireless transport is proposed and experimentally demonstrated. Bit error rate (BER) and eye diagram perform brilliantly through a serious investigation in systems. Such a two-way fiber-wireless convergence system is a promising option, it reveals a prominent one to present its advancement in integration of distribute fiber and in-house network.

  10. Radio emission in Mercury magnetosphere

    Science.gov (United States)

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

    2016-10-01

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

  11. Beamforming with Reduced Complexity in MIMO Cooperative Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Mehdi Ghamari Adian

    2014-01-01

    Full Text Available An approach for beamforming with reduced complexity in MIMO cooperative cognitive radio networks (MIMO-CCRN is presented. Specifically, a suboptimal approach with reduced complexity is proposed to jointly determine the transmit beamforming (TB and cooperative beamforming (CB weight vectors along with antenna subset selection in MIMO-CCRN. Two multiantenna secondary users (SU constitute the desired link, one acting as transmitter (SU TX and the other as receiver (SU RX and they coexist with single-antenna primary and secondary users. Some of single antenna secondary users are recruited by desired link as cooperative relay. The maximization of the achievable rates in the desired link is the objective of this work, provided to interference constraints on the primary users are not violated. The objective is achieved by exploiting transmit beamforming at SU TX, cooperation of some secondary users, and cooperative beamforming. Meanwhile, the costs associated with RF chains at the radio front end at SU RX are reduced. Through simulations, it is shown that better performance in the desired link is attained, as a result of cooperation of SUs.

  12. Technology, Empowerment and Community Radio

    OpenAIRE

    Scifo, Salvatore

    2015-01-01

    This article will provide an overview of the conceptual contours of community media and community radio, highlighting some of the key questions shaping the debate and, with the help of a case study, show how digital media in the context of community radio can help local groups to get a voice in their local media systems, and how a university-based radio station, and its students and volunteers, play an important role for a more diverse and vibrant media content available in their area.

  13. Radio Search For Extrasolar Planets

    Science.gov (United States)

    Zarka, P.

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

  14. Advanced Radio Resource Management for Multi Antenna Packet Radio Systems

    OpenAIRE

    Stanislav Nonchev; Mikko Valkama

    2010-01-01

    In this paper, we propose fairness-oriented packet scheduling (PS) schemes with power-efficientcontrol mechanism for future packet radio systems. In general, the radio resource managementfunctionality plays an important role in new OFDMA based networks. The control of the networkresource division among the users is performed by packet scheduling functionality based on maximizingcell coverage and capacity satisfying, and certain quality of service requirements. Moreover, multiantennatransmit-r...

  15. Recent Radio Monitoring of Microquasars with RATAN-600 Radio Telescope

    CERN Document Server

    Trushkin, S A; Kotani, T; Nizhelskij, N A; Namiki, M; Tsuboi, M; Voitsik, P A

    2007-01-01

    We report about the multi-frequency (1-30 GHz) daily monitoring of the radio flux variability of the three microquasars: SS433, GRS1915+105 and Cyg X-3 during the period from September 2005 to May 2006. 1. We detected clear correlation of the flaring radio fluxes and X-rays 'spikes' at 2-12 keV emission detected in RXTE ASM from GRS1915+105 during eight relatively bright (200-600 mJy) radio flares in October 2005. The 1-22 GHz spectra of these flares in maximum were optically thick at frequencies lower 2.3 GHz and optically thin at the higher frequencies. During the radio flares the spectra of the X-ray spikes become softer than those of the quiescent phase. Thus these data indicated the transitions from very high/hard states to high/soft ones during which massive ejections are probably happened. These ejections are visible as the detected radio flares. 2. After of the quiescent radio emission we have detected a drop down of the fluxes (~20 mJy) from Cyg X-3. That is a sign of the following bright flare. Inde...

  16. Radio frequency integrated circuit design for cognitive radio systems

    CERN Document Server

    Fahim, Amr

    2015-01-01

    This book fills a disconnect in the literature between Cognitive Radio systems and a detailed account of the circuit implementation and architectures required to implement such systems.  Throughout the book, requirements and constraints imposed by cognitive radio systems are emphasized when discussing the circuit implementation details.  In addition, this book details several novel concepts that advance state-of-the-art cognitive radio systems.  This is a valuable reference for anybody with background in analog and radio frequency (RF) integrated circuit design, needing to learn more about integrated circuits requirements and implementation for cognitive radio systems. ·         Describes in detail cognitive radio systems, as well as the circuit implementation and architectures required to implement them; ·         Serves as an excellent reference to state-of-the-art wideband transceiver design; ·         Emphasizes practical requirements and constraints imposed by cognitive radi...

  17. Survey of Channel and Radio Propagation Models for Wireless MIMO Systems

    Directory of Open Access Journals (Sweden)

    A. Burr

    2007-02-01

    Full Text Available This paper provides an overview of the state-of-the-art radio propagation and channel models for wireless multiple-input multiple-output (MIMO systems. We distinguish between physical models and analytical models and discuss popular examples from both model types. Physical models focus on the double-directional propagation mechanisms between the location of transmitter and receiver without taking the antenna configuration into account. Analytical models capture physical wave propagation and antenna configuration simultaneously by describing the impulse response (equivalently, the transfer function between the antenna arrays at both link ends. We also review some MIMO models that are included in current standardization activities for the purpose of reproducible and comparable MIMO system evaluations. Finally, we describe a couple of key features of channels and radio propagation which are not sufficiently included in current MIMO models.

  18. An Achievable Rate Region for Cognitive Radio Channel With Common Message

    CERN Document Server

    Monemizadeh, Mostafa; Hodtani, Ghosheh Abed

    2011-01-01

    The cognitive radio channel with common message (CRCC) is considered. In this channel, similar to the cognitive radio channel (CRC), we have a cognitive user which has full non-causal knowledge of the primary message, and like the interference channel with common message (ICC), the information sources at the two transmitters are statistically dependent and the senders need to transmit not only the private message but also certain common message to their corresponding receivers. By using a specific combination of superposition coding, binning scheme and simultaneous decoding, we propose a unified achievable rate region for the CRCC which subsumes the several existing results for the CRC, ICC, interference channel without common message (IC), strong interference channel and compound multiple access channel with common information (SICC and CMACC).

  19. Survey of Channel and Radio Propagation Models for Wireless MIMO Systems

    Directory of Open Access Journals (Sweden)

    Kyösti P

    2007-01-01

    Full Text Available This paper provides an overview of the state-of-the-art radio propagation and channel models for wireless multiple-input multiple-output (MIMO systems. We distinguish between physical models and analytical models and discuss popular examples from both model types. Physical models focus on the double-directional propagation mechanisms between the location of transmitter and receiver without taking the antenna configuration into account. Analytical models capture physical wave propagation and antenna configuration simultaneously by describing the impulse response (equivalently, the transfer function between the antenna arrays at both link ends. We also review some MIMO models that are included in current standardization activities for the purpose of reproducible and comparable MIMO system evaluations. Finally, we describe a couple of key features of channels and radio propagation which are not sufficiently included in current MIMO models.

  20. Laboratory measurements of super-resolving Toraldo pupils for radio astronomical applications

    CERN Document Server

    Olmi, Luca; Cresci, Luca; D'Agostino, Francesco; Migliozzi, Massimo; Mugnai, Daniela; Natale, Enzo; Nesti, Renzo; Panella, Dario; Stefani, Lorenzo

    2016-01-01

    The concept of super-resolution refers to various methods for improving the angular resolution of an optical imaging system beyond the classical diffraction limit. Although several techniques to narrow the central lobe of the illumination Point Spread Function have been developed in optical microscopy, most of these methods cannot be implemented on astronomical telescopes. A possible exception is represented by the variable transmittance filters, also known as "Toraldo Pupils" (TPs) since they were introduced for the first time by G. Toraldo di Francia in 1952. In the microwave range, the first successful laboratory test of TPs was performed in 2003. These first results suggested that TPs could represent a viable approach to achieve super-resolution in Radio Astronomy. We have therefore started a project devoted to a more exhaustive analysis of TPs and how they could be implemented on a radio telescope. In the present work we report on the results of extensive microwave measurements, using TPs with different ...

  1. Solid State Transmitters for Water Vapor and Ozone DIAL Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We have developed a common architecture for laser transmitters that address requirements for water vapor as well as ground and airborne ozone lidar systems. Our...

  2. An unobtrusive liquid sensor utilizing a micromilled RF spark gap transmitter and resonant cavity

    Science.gov (United States)

    Berry, H.; Wilson, C.

    2009-09-01

    This paper reports on a new dielectric liquid sensor that utilizes an RF sparkgap transmitter coupled with an aluminum microwave resonant cavity. The transmitter is a micromilled polymer transmitter housing with patterned copper electrodes that generate micro-arcs. This transmitter which operates outside the measured liquid generates a directed ultrawideband signal which is received by the aluminum waveguide. Absorption resonances in the microwave cavity, measured with a spectrum analyzer are a function of the liquids' dielectric constant at lower frequencies, as well as from molecular vibrations/rotations at higher frequencies. In many chemical manufacturing processes, liquids being manufactured are removed, tested in a lab, and then disposed of, or else they will contaminate the full batch. In beer brewing, for instance, samples are removed, density tested for alcohol content, then disposed of. Using this sensor, the chemical process could be continuously monitored by a computerized system without risk of contamination.

  3. A CMOS UWB transmitter with Vivaldi Array for Ultra-fast Beam steering microwave radar

    National Research Council Canada - National Science Library

    De Oliveira, Alexandre M; Ascama, Héctor D. O; Hiramatsu, Roberto K; Kofuji, Sérgio T; Perotoni, Marcelo B; Justo, João F

    2013-01-01

    This work presents a new Ultra Wide Band (UWB) beamforming fifth-order derivative Gaussian pulse transmitter with dual small Vivaldi antennas for remote acquisition of vital signals in impulse radar applications...

  4. Compact self-contained electrical-to-optical converter/transmitter

    Energy Technology Data Exchange (ETDEWEB)

    Seligmann, D.A.; Moss, W.C.; Valk, T.C.; Conder, A.D.

    1992-12-31

    An electrical-to-optical converter/transmitter is disclosed. A first optical receiver and a second optical receiver are provided for receiving a calibrate command and a power switching signal, respectively, from a remote processor. A third receiver is provided for receiving an analog electrical signal from a transducer. A calibrator generates a reference signal in response to the calibrate command. A combiner mixes the electrical signal with the reference signal to form a calibrated signal. A converter converts the calibrated signal to an optical signal. A transmitter transmits the optical signal to the remote processor. A primary battery supplies power to the calibrator, the combiner, the converter, and the transmitter. An optically-activated switch supplies power to the calibrator, the combiner, the converter, and the transmitter in response to the power switching signal. An auxiliary battery supplies power continuously to the switch means.

  5. Two-flux transfer matrix model for predicting the reflectance and transmittance of duplex halftone prints.

    Science.gov (United States)

    Mazauric, Serge; Hébert, Mathieu; Simonot, Lionel; Fournel, Thierry

    2014-12-01

    We introduce a model allowing convenient calculation of the spectral reflectance and transmittance of duplex prints. It is based on flux transfer matrices and enables retrieving classical Kubelka-Munk formulas, as well as extended formulas for nonsymmetric layers. By making different assumptions on the flux transfers, we obtain two predictive models for the duplex halftone prints: the "duplex Clapper-Yule model," which is an extension of the classical Clapper-Yule model, and the "duplex primary reflectance-transmittance model." The two models can be calibrated from either reflectance or transmittance measurements; only the second model can be calibrated from both measurements, thus giving optimal accuracy for both reflectance and transmittance predictions. The conceptual differences between the two models are deeply analyzed, as well as their advantages and drawbacks in terms of calibration. According to the test carried out in this study with paper printed in inkjet, their predictive performances are good provided appropriate calibration options are selected.

  6. Conductive Polymer Microelectrodes for on-chip measurement of transmitter release from living cells

    DEFF Research Database (Denmark)

    Larsen, Simon Tylsgaard; Matteucci, Marco; Taboryski, Rafael J.

    2012-01-01

    driven cell trapping inside closed chip devices. Conductive polymer microelectrodes were used to measure transmitter release using electrochemical methods such as cyclic voltammetry and constant potential amperometry. By measuring the oxidation current at a cyclic voltammogram, the concentration...

  7. Television Transmitter Locations, Published in 2006, 1:1200 (1in=100ft) scale, Farmer.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Television Transmitter Locations dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Field Survey/GPS information as of 2006. Data...

  8. Flexible High Energy Lidar Transmitter for Remote Gas and Wind Sensing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fibertek proposes a high energy and flexible operation 1570 nm pulsed lidar transmitter for airborne and space-based remote CO2 gas and doppler wind sensing. The...

  9. Use of a novel acoustic dissolved oxygen transmitter for fish telemetry

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Aarestrup, Kim; Steffensen, J.F.

    2006-01-01

    The multiple responses of fishes to changes in dissolved oxygen saturations have been studied widely in the laboratory. In contrast only few studies have included field observations. The objective of the present study was to evaluate the performance of a novel acoustic dissolved oxygen transmitter...... for field biotelemetry. The results demonstrated that the output of the transmitter was unaffected by three different temperatures (10 to 30 degrees C) and described the dissolved oxygen saturation with high accuracy (r(2) > 0.99) over the entire range of 0 to 191% saturation. The response time (>= 90......% of end value) of the transmitter was 12 s both in terms of decreasing (100 to 0%) and increasing (0 to 100%) oxygen saturations. When externally attached to fishes the present findings support the use of the transmitter for reliable dissolved oxygen measurements on individuals living in environments...

  10. Standard Practice for Calculation of Photometric Transmittance and Reflectance of Materials to Solar Radiation

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1988-01-01

    1.1 This practice describes the calculation of luminous (photometric) transmittance and reflectance of materials from spectral radiant transmittance and reflectance data obtained from Test Method E 903. 1.2 Determination of luminous transmittance by this practice is preferred over measurement of photometric transmittance by methods using the sun as a source and a photometer as detector except for transmitting sheet materials that are inhomogeneous, patterned, or corrugated. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  11. Space-Qualifiable 1064 nm Fiber Based Transmitter for Long Range Optical Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fibertek has developed transmitters for Lidar and 3D imaging applications based on fiber optics architectures both at 1064nm. We have demonstrated an all fiber...

  12. Optical calculations and in-situ measurement of transmittance spectra of contaminant thin films

    Science.gov (United States)

    Shimazaki, Kazunori; Miyazaki, Eiji; Kimoto, Yugo

    2016-09-01

    Molecular contaminants outgassed from organic materials used for the spacecraft degrade the performance of optical surfaces of spacecraft. The influence of contaminants outgassed from epoxy resin on the spectral transmittance of the quartz substrate was investigated with an in-situ measurement system. The system can deposit the contaminants on temperature-controlled quartz substrates and the transmittance spectra were measured immediately after deposition in vacuum ambient. We tried to obtain the optical constants of the contaminant using transmittance spectrum and simple optical models for optical calculations. The optical constants were described with a harmonic oscillator model and the effective medium approximation model. This paper reports the in-situ measurement results of transmittance spectra of the epoxy-resin-induced contaminants. In addition, the result of optical calculations using the obtained optical constants were compared to the measurement results.

  13. Transmittance, Reflectance, and Emission Spectroscopy of Meteorites from the UV to the IR Spectral Range

    Science.gov (United States)

    Maturilli, A.; Helbert, J.; Koulen, J. M.; Ferrari, S.; Martellato, E.

    2016-08-01

    Transmittance, reflectance, and emissivity Spectra of six meteorites have been collected at the Planetary Spectroscopy Laboratory (PSL) of DLR in Berlin in the whole spectral range from the UV to the IR.

  14. High-efficiency resonantly pumped 1550-nm fiber-based laser transmitter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — nLight proposes the development of high efficiency, high average power 1550-nm laser transmitter system that is based on Er-doped fiber amplifier resonantly pumped...

  15. Effect of dust on the transmittance of low density polyethylene glazing in a tropical climate

    Energy Technology Data Exchange (ETDEWEB)

    Mastekbayeva, G.A.; Kumar, S. [Asian Inst. of Technology, Energy Program, Pathumthani (Thailand)

    2000-07-01

    The performance of solar systems (thermal or photovoltaic) is influenced by the ability of the glazing to transmit solar radiation to the collection surface, besides other factors, such as, incident radiation, tilt of collector, properties of materials, operating strategy, surroundings, etc. This paper discusses the influence of dust on the transmittance of a 0.2-mm-thick low-density polyethylene (LDPE) glazing used commonly in solar air heaters. The reduction in transmittance due to various dust deposition densities of Bangkok clay (size 53-75 {mu}m) has been measured and a correlation relating the dust deposition density and the transmittance given. Experimental observations of natural dust accumulation on an inclined (15deg) LDPE glazing at a tropical climatic condition during a 30-day period indicates a dust accumulation of 3.72 g/m{sup 2} and is found to reduce the global transmittance of the glazing from about 87.9% to 75.8%. (Author)

  16. Compact, Rugged and Low-Cost Atmospheric Ozone DIAL Transmitter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Bridger Photonics Inc. (Bridger) proposes to develop the most compact, efficient and low-cost ultra-violet ozone differential absorption lidar (DIAL) transmitter...

  17. Innovativeness and the Public Radio Audience.

    Science.gov (United States)

    Williams, Wenmouth, Jr.; Krugman, Dean M.

    1981-01-01

    A public radio audience was surveyed to test the hypothesis that a relationship exists between innovativeness and public radio listening. Rather than supporting the hypothesis, findings indicate that the entertainment and information elements of public radio are the primary attractions for the public radio audience. (MER)

  18. On the evaluation of Web Radio

    NARCIS (Netherlands)

    Field, A.N.; Hartel, Pieter H.

    We develop an evaluation method for Web radio, and perform it to see what we can be learnt about seven prominent Web radio sites. We also evaluate a commercial FM radio station for control purposes. We present a taxonomy of Web radio, and we give our observations and conclusions on this evaluation.

  19. On the evaluation of Web Radio

    NARCIS (Netherlands)

    Field, A.N.; Hartel, P.H.

    2001-01-01

    We develop an evaluation method for Web radio, and perform it to see what we can be learnt about seven prominent Web radio sites. We also evaluate a commercial FM radio station for control purposes. We present a taxonomy of Web radio, and we give our observations and conclusions on this evaluation.

  20. On the evaluation of Web Radio

    NARCIS (Netherlands)

    Field, A.N.; Hartel, Pieter H.

    2001-01-01

    We develop an evaluation method for Web radio, and perform it to see what we can be learnt about seven prominent Web radio sites. We also evaluate a commercial FM radio station for control purposes. We present a taxonomy of Web radio, and we give our observations and conclusions on this evaluation.