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1

Radio determination satellite service  

NASA Astrophysics Data System (ADS)

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

Briskman, Robert D.

1990-07-01

2

Satellite Imaging Corporation: IKONOS Satellite Images  

NSDL National Science Digital Library

Satellite Imaging Corporation (SIC) acquires and processes imagery from the IKONOS satellite as well as others and makes the products available through their website. The images in the gallery are arranged in several categories based on what applications the images might be useful for, such as Agriculture, Coastal Management, or Sports and Tourism.

Satellite Imaging Corporation

3

Satellite broadcasting of sound radio  

Microsoft Academic Search

Direct broadcasting by Satellite (DBS) of television signals to the home has received much attention recently; in contrast, less attention has been paid to sound-only (i.e. radio) broadcasting from satellites. The paper reviews the present range of terrestrial sound broadcasting and explores the possible scope and technical feasibility of using satellites. Satellite broadcasting of sound programmes to receivers of all

J. H. Stott

1986-01-01

4

The Aerospace Corporation 2009 Communication Satellite Systems  

E-print Network

© The Aerospace Corporation 2009 Communication Satellite Systems Trends and Network Aspects Paul://www.aero.org/ Lee Center, Caltech 13 April 2009 #12;22 Communication Satellites · Brief History by Decade · Trends: ­ Communication Satellites, fifth edition, by D. Martin, P. Anderson, L. Bartamian, Aerospace / AIAA Press, 2006

Low, Steven H.

5

Direct Broadcast Satellite: Radio Program  

NASA Technical Reports Server (NTRS)

NASA is committed to providing technology development that leads to the introduction of new commercial applications for communications satellites. The Direct Broadcast Satellite-Radio (DBS-R) Program is a joint effort between The National Aeronautics and Space Administration (NASA) and The United States Information Agency/Voice of America (USIA/VOA) directed at this objective. The purpose of this program is to define the service and develop the technology for a direct-to-listener satellite sound broadcasting system. The DBS-R Program, as structured by NASA and VOA, is now a three-phase program designed to help the U.S. commercial communications satellite and receiver industry bring about this new communications service. Major efforts are being directed towards frequency planning hardware and service development, service demonstration, and experimentation with new satellite and receiver technology.

Hollansworth, James E.

1992-01-01

6

Geostar Radio Determination Satellite System  

NASA Astrophysics Data System (ADS)

The Geostar Radio Determination Satellite System is designed to provide accurate position information and ancillary message passing capability for land mobile, marine, and aeronautical users in the United States and eventually worldwide. The Geostar system is a random access spread spectrum system capable of high positioning accuracy. Geostar can support a large population of users operating inexpensive transceivers. This paper examines the Geostar system positioning technique, error sources, anticipated accuracy, and potential applications.

Richards, Robert T.

7

Satellite Television Corporations's DBS system - An update  

NASA Astrophysics Data System (ADS)

In late 1980, a request was made for approval of a direct broadcast satellite (DBS) system. The considered DBS system is to provide nationwide pay-television service on a subscription basis. The system proposed in the application to the Federal Communications Commission would provide three channels of television, using four three-channel satellites. Attention is given to the system configuration, system tradeoffs, a plan of the 1983 Regional Administrative Radio Conference, orbit locations and channel frequencies, satellite status, home equipment status, advanced concepts, and the status of the Las Vegas Broadcast Complex. AIAA Paper 84-0664

Martin, E. R.

8

Corporate strategies for satellite communications  

NASA Astrophysics Data System (ADS)

Terrestrial and satellite broadcast communications technologies, while clearly providing tremendous benefits in many market sectors, present something of a challenge to the strategic planning bodies in most organizations. This is because there is no existing analog for the services in the organizations' telecommunications networks. The marketplace is therefore a confusing place for such organizations swamped as it is with competing service providers, technologies, and services, and their telecommunications strategies cannot cope with the opportunities because they have been founded on the exploitation of point to point connections. A mechanism for creating and bounding strategies which combines the rigor of structured analysis with a comprehensive categorization of strategic directions which has been successfully used to generate new paneuropean telecommunications strategies is presented.

Birch, David G. W.; Buck, S. Peter

1991-10-01

9

Ionospheric scintillations of geostationary satellite radio waves  

Microsoft Academic Search

Observations of the scintillations associated with the major geomagnetic storms occurring on July 14 and September 7, 1982 are described. On July 14, relatively weak and long-lasting scintillations were observed on 136-MHz radio wave from the geostationary satellite, ETS-II. These scintillations have features somewhat different from those under geomagnetically quiet conditions: (1) they appeared at local times between 0 h

H. Kumagai; T. Ogawa; T. Hori

1986-01-01

10

The 'Geostar' radio determination satellite system  

NASA Astrophysics Data System (ADS)

The proposed Geostar system which links portable and mobile terminals directly through satellite relays to a ground-based computer is capable of providing the following services in a variety of transportation modes: (1) navigational positioning, (2) terrain warning to pilots and hazard warning to mariners, (3) approach guidance for aircraft and (4) two-way digital message service. Able to operate in a supplementary or advisory mode, the Geostar system combines the existing technologies of orbital satellites, computers and integrated circuits. It consists of the following: (1) a ground station with a computer, two or more satellites at fixed locations in earth orbit, and terminals carried by aircraft, surface vehicles, etc. Geostar's practical implications are discussed as well as the fitting of its necessary radio frequencies in the ITU table of allocations.

Oneill, G. K.

1986-05-01

11

Direct broadcast satellite-radio, receiver development  

NASA Technical Reports Server (NTRS)

The status of the ongoing Direct Broadcast Satellite-Radio (DBS-R) Receiver Development Task being performed at the Jet Propulsion Laboratory, California Institute of Technology (JPL) is reported. This work is sponsored by the Voice of America/U.S. Information Agency through an agreement with NASA. The objective of this task is to develop, build, test, and demonstrate a prototype receiver that is compatible with reception of digital audio programs broadcast via satellites. The receiver is being designed to operate under a range of reception conditions, including fixed, portable, and mobile, as well as over a sufficiently wide range of bit rates to accommodate broadcasting systems with different cost/audio quality objectives. While the requirements on the receiver are complex, the eventual goal of the design effort is to make the design compatible with low cost production as a consumer product. One solution may be a basic low cost core design suitable for a majority of reception conditions, with optional enhancements for reception in especially difficult environments. Some of the receiver design parameters were established through analysis, laboratory tests, and a prototype satellite experiment accomplished in late 1991. Many of the necessary design trades will be made during the current simulation effort, while a few of the key design options will be incorporated into the prototype for evaluation during the planned satellite field trials.

Vaisnys, A.; Bell, D.; Gevargiz, J.; Golshan, Nasser

1993-01-01

12

Satellite sound broadcasting to fixed, portable and mobile radio receivers  

Microsoft Academic Search

Direct broadcasting by satellite (DBS) of television signals to the home has received much attention recently; less attention has been paid to sound-only (i.e., radio) broadcasting from satellites. This Report reviews the present range of terrestrial sound broadcasting and explores the possible scope and technical feasibility of using satellites. Satellite broadcasting of sound programs to receivers of all types, including

J. H. Stott

1985-01-01

13

Radio occultation based on BeiDou satellite navigation  

NASA Astrophysics Data System (ADS)

With the development of GNSS systems, it has become a tendency that radio occultation is used to sense the Earth's atmosphere. By this means, the moisture, temperature, pressure, and total electron content can be derived. Based on the sensing results, more complicated models for atmosphere might come into being. Meteorology well benefits from this technology. As scheduled, the BD satellite navigation system will have a worldwide coverage by the end of 2020. Radio occultation studies in China have been highlighted in the recent decade. More and more feasibilities reports have been published in either domestic or international journals. Herein, some scenarios are proposed to assess the coverage of radio occultation based on two different phases of BD satellite navigation system. Phase one for BD is composed of GEO,IGSO and several MEO satellites. Phase two for BD consists mostly of 24 MEO satellites, some GEO and IGSO satellites. The characteristics of radio occultation based on these two phases are presented respectively.

Jiang, Hu; Hu, Haiying; Shen, Xue-min; Gong, Wenbin; Zhang, Yonghe

2014-11-01

14

Satellite emission radio interferometric earth surveying series - GPS geodetic system  

NASA Technical Reports Server (NTRS)

A concept called SERIES (satellite emissions radio interferometric earth surveying) which makes use of GPS (global positioning system) radio transmissions without any satellite modifications, is described. Through the use of very long baseline interferometry (VLBI) and its calibration methods, 0.5 to 3 cm three dimensional baseline accuracy can be achieved over distances of 2 to 200 km respectively, with only 2 hours of on-site data acquisition. Attention is given to such areas as: the radio flux equivalent of GPS transmissions, synthesized delay precision, transmission and frequency subsystem requirements, tropospheric and ionospheric errors. Applications covered include geodesy and seismic tectonics.

Macdoran, P. F.

1979-01-01

15

Wave propagation and earth satellite radio emission studies  

NASA Technical Reports Server (NTRS)

Radio propagation studies of the ionosphere using satellite radio beacons are described. The ionosphere is known as a dispersive, inhomogeneous, irregular and sometimes even nonlinear medium. After traversing through the ionosphere the radio signal bears signatures of these characteristics. A study of these signatures will be helpful in two areas: (1) It will assist in learning the behavior of the medium, in this case the ionosphere. (2) It will provide information of the kind of signal characteristics and statistics to be expected for communication and navigational satellite systems that use the similar geometry.

Yeh, K. C.; Liu, C. H.; Flaherty, B. J.

1974-01-01

16

Direct broadcast satellite-radio, space-segment/receiver tradeoffs  

NASA Technical Reports Server (NTRS)

The balance between receiver complexity and the required satellite equivalent isotropically radiated power (EIRP) for Direct Broadcast Satellite-Radio (DBS-R) service is addressed. In general the required receiver complexity and cost can be reduced at the expense of higher space-segment cost by allowing a higher satellite EIRP. The tradeoff outcome is sensitive to the total number of anticipated receivers in a given service area, the number of audio programs, and the required audio quality. An understanding of optimum choice of satellite EIRP for DBS-R under various service requirements is a critical issue at this time when International Radio Consultative Committee (CCIR) is soliciting input in preparation for the International Telecommunications Union (ITU) planning conference for the service.

Golshan, Nasser

1993-01-01

17

FCC proposes sharing of weather satellite radio bands  

NASA Astrophysics Data System (ADS)

The Federal Communications Commission (FCC) has published a notice of a proposed ruling in the Federal Register that could lead to the licensing of millions of radio transmitters in the 1700-1710-MHz band. Transmission of data from meteorological satellites may be affected by this proposal: Since 1979, the National Oceanic and Atmospheric Administration (NOAA) has been using that band for satellite-to-earth transmission for the High-Resolution Picture Transmission (HRPT) program.

18

Galileo Radio Occultations of the Galilean Satellites  

NASA Astrophysics Data System (ADS)

Between 1997 and 1999, the S-band (2.5 GHz)radio signal of the Galileo orbiter was used to obtain radio occultation data on the ionospheres and plasma environments of Io, Europa, Ganymede, and Callisto. These data revealed the existence of ionospheres on Europa(Kliore,et al.,Science,277,355(1997)), Callisto(Kliore,et al.,JGR-Sp.Phys.,in press), and Ganymede(c.f., Kliore, Anabtawi, and Nagy,BAAS,33,1084(2001)), in addition to providing more comprehensive measurements of the ionosphere of Io(Hinson, et al.,JGR-Sp.Phys.,103,29343(1998)). These measurements were made at various positions of the Earth relative to the Sun and Jupiter, ranging from near opposition to near superior conjunction. The effects of solar plasma on the radio signal are maximal at conjunction, and minimal at opposition, which is apparent from the baseline noise in the radio occultation data. When expressed as the standard deviation of the electron density fluctuations, this amounts to about 500 cm-3 near opposition, and more than 1500 cm-3 at conjunction. In addition to the solar plasma effects, local plasma fluctuations are also apparent, especially at Europa and the downstream side of Io. This research was performed at the Jet Propulsion Laboratory, California Institute of Technology, with NASA funding from the Galileo project.

Kliore, A. J.; Anabtawi, A.

2002-09-01

19

Radio frequency interference from near-earth satellites  

NASA Technical Reports Server (NTRS)

A pessimistic statistical model was developed for predicting the extent of radio frequency interference (RF1). Based on the assumptions underlying the model, DSN S-band operations can expect one RF1 interruption every 4.1 days, with the average incident lasting 24 s. This implies that 52 or more such satellites, with uncorrelated orbital trajectories, will cause in excess of 5 min of RF1 per day at a DSN station.

Levitt, B. K.; Lesh, J. R.

1977-01-01

20

Method of resolving radio phase ambiguity in satellite orbit determination  

NASA Technical Reports Server (NTRS)

For satellite orbit determination, the most accurate observable available today is microwave radio phase, which can be differenced between observing stations and between satellites to cancel both transmitter- and receiver-related errors. For maximum accuracy, the integer cycle ambiguities of the doubly differenced observations must be resolved. To perform this ambiguity resolution, a bootstrapping strategy is proposed. This strategy requires the tracking stations to have a wide ranging progression of spacings. By conventional 'integrated Doppler' processing of the observations from the most widely spaced stations, the orbits are determined well enough to permit resolution of the ambiguities for the most closely spaced stations. The resolution of these ambiguities reduces the uncertainty of the orbit determination enough to enable ambiguity resolution for more widely spaced stations, which further reduces the orbital uncertainty. In a test of this strategy with six tracking stations, both the formal and the true errors of determining Global Positioning System satellite orbits were reduced by a factor of 2.

Councelman, Charles C., III; Abbot, Richard I.

1989-01-01

21

Fade durations in satellite-path mobile radio propagation  

NASA Astrophysics Data System (ADS)

Fades on satellite to land mobile radio links are caused by several factors, the most important of which are multipath propagation and vegetative shadowing. Designers of vehicular satellite communications systems require information about the statistics of fade durations in order to overcome or compensate for the fades. Except for a few limiting cases, only the mean fade duration can be determined analytically, and all other statistics must be obtained experimentally or via simulation. This report describes and presents results from a computer program developed at Virginia Tech to simulate satellite path propagation of a mobile station in a rural area. It generates rapidly-fading and slowly-fading signals by separate processes that yield correct cumulative signal distributions and then combines these to simulate the overall signal. This is then analyzed to yield the statistics of fade duration.

Schmier, Robert G.; Bostian, Charles W.

1986-12-01

22

Fade durations in satellite-path mobile radio propagation  

NASA Technical Reports Server (NTRS)

Fades on satellite to land mobile radio links are caused by several factors, the most important of which are multipath propagation and vegetative shadowing. Designers of vehicular satellite communications systems require information about the statistics of fade durations in order to overcome or compensate for the fades. Except for a few limiting cases, only the mean fade duration can be determined analytically, and all other statistics must be obtained experimentally or via simulation. This report describes and presents results from a computer program developed at Virginia Tech to simulate satellite path propagation of a mobile station in a rural area. It generates rapidly-fading and slowly-fading signals by separate processes that yield correct cumulative signal distributions and then combines these to simulate the overall signal. This is then analyzed to yield the statistics of fade duration.

Schmier, Robert G.; Bostian, Charles W.

1986-01-01

23

Satellite observations of transient radio impulses from thunderstorms  

SciTech Connect

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

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

1999-06-01

24

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.  

Code of Federal Regulations, 2013 CFR

...Licensing provisions for the 2.3 GHz satellite digital audio radio service...144 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...

2013-10-01

25

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.  

Code of Federal Regulations, 2010 CFR

...Licensing provisions for the 2.3 GHz satellite digital audio radio service...144 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...

2010-10-01

26

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.  

Code of Federal Regulations, 2011 CFR

...Licensing provisions for the 2.3 GHz satellite digital audio radio service...144 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...

2011-10-01

27

47 CFR 25.214 - Technical requirements for space stations in the Satellite Digital Audio Radio Service and...  

Code of Federal Regulations, 2013 CFR

...214 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards 25...requirements for space stations in the Satellite Digital Audio Radio Service...

2013-10-01

28

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.  

Code of Federal Regulations, 2012 CFR

...Licensing provisions for the 2.3 GHz satellite digital audio radio service...144 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...

2012-10-01

29

47 CFR 25.214 - Technical requirements for space stations in the satellite digital audio radio service and...  

Code of Federal Regulations, 2010 CFR

...214 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards 25...requirements for space stations in the satellite digital audio radio service...

2010-10-01

30

47 CFR 25.214 - Technical requirements for space stations in the satellite digital audio radio service and...  

Code of Federal Regulations, 2011 CFR

...214 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards 25...requirements for space stations in the satellite digital audio radio service...

2011-10-01

31

47 CFR 25.214 - Technical requirements for space stations in the satellite digital audio radio service and...  

Code of Federal Regulations, 2012 CFR

...214 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards 25...requirements for space stations in the satellite digital audio radio service...

2012-10-01

32

47 CFR 25.214 - Technical requirements for space stations in the Satellite Digital Audio Radio Service and...  

...214 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards 25...requirements for space stations in the Satellite Digital Audio Radio Service...

2014-10-01

33

76 FR 57923 - Establishment of Rules and Policies for the Satellite Digital Audio Radio Service in the 2310...  

Federal Register 2010, 2011, 2012, 2013

...FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 25...Rules and Policies for the Satellite Digital Audio Radio Service...Frequency Band AGENCY: Federal Communications Commission. ACTION: Final...requirements contained in the Satellite Digital Audio Radio...

2011-09-19

34

The Federal Communications Commission and the Communications Satellite Corporation: A Question of Ownership.  

ERIC Educational Resources Information Center

When NASA announced in 1960 that private enterprise would produce communication satellites, rather than the Federal government, several large corporations proposed a joint venture involving a group of international carriers and electronic manufacturers, while American Telephone and Telegraph requested sole ownership. At that time, the Federal

Lee, William E.

35

78 FR 44029 - Establishment of Rules and Policies for the Digital Audio Radio Satellite Service in the 2310...  

Federal Register 2010, 2011, 2012, 2013

...Digital Audio Radio Satellite Service in the...AGENCY: Federal Communications Commission. ACTION...Operation of Wireless Communications Services in the...Digital Audio Radio Satellite Service in the...Operation of Wireless Communications Services in the...Digital Audio Radio Satellite Service in...

2013-07-23

36

Monitoring of Earthquake Disasters by Satellite Radio Tomography  

NASA Astrophysics Data System (ADS)

This work addresses lithospheric-ionospheric coupling during strong earthquakes (EQ). Particular interest is placed on the physical phenomena preceding EQs - the precursors. We discuss both the ionospheric implications of EQs, and the ionospheric precursors to EQ. The requisite ionospheric sounding is carried out using satellite navigational system data; the data are analyzed using the methods of satellite radio tomography (RT). Signals from both low-orbiting beacons (Transit, Tsikada, etc.) and high orbiting global navigational satellite systems (GNSS including GPS and GLONASS) are used. The resulting 2D and 3D tomographic images and their time flow (4D RT) make it possible to study the spatiotemporal structure of ionospheric perturbations induced by EQs and EQ precursors, and to distinguish ionospheric responses to processes of EQ preparation against the effects of other factors. Low-orbital RT (LORT) provides almost "instantaneous" (with a time span of 5-8 min) 2-D snapshots of the electron density over the seismically active region of interest. LORT allows 2D imaging of various anomalies, including wave structures such as ionospheric manifestations of acoustic-gravity waves (AGW), wave-like disturbances, and solitary waves with the gaps between images, depending on the number of operating satellites (currently, 30-100 minutes). High-orbital RT (HORT) is capable of imaging 4D distributions of ionospheric plasma (resulting in 3D snapshots every 20-30 minutes). Using this approach, one can reconstruct RT images of ionospheric irregularities, wave structures, and perturbations such as solitary waves. In regions with a sufficient number of GNSS receivers (California, Japan), 4-D RT images can be generated every 2-4 minutes. The spatial resolution of LORT and HORT systems is on the order of 20-40, and 100 km, respectively. The combination of LORT and HORT systems has the potential for exploiting data provided by other experimental techniques, including radio occultation, ionosonde, and radar measurements, inter alia. Further integration of RT systems with other multi-instrumental observations of EQ-related phenomena is possible. We present the results of long-term RT studies of the ionosphere over California, Alaska, and Southeast Asia (Taiwan region). We used the experimental data from the LORT systems in Alaska and Taiwan. At present, LORT system in California is put into operation. The input for HORT imaging was the data from IGS, UNAVCO, and Japan GPS network stations. A variety of examples are given to illustrate the ionospheric perturbations associated with EQs and to illustrate EQ-related, ionospheric precursors including specific ionospheric disturbances, AGW, and solitary-wave-like perturbations. Several dozen precursors are identified from the results of many years of RT studies in Alaska and the Taiwan region during the period from 2006-2008. We discuss the results of a HORT analysis of a series of recent EQs including San Simeon (2003), Parkfield (2004), Sumatra (2004), Sichuan (China, 2008), Haiti (2010), Chile (2010), Japan (Tohoku, 2011), and other events. We are grateful to Dr. L.-C.Tsai and Northwest Research Associates, Inc., for providing raw RT data for Taiwan and Alaska.

Kunitsyn, V.; Andreeva, E.; Nesterov, I.; Rekenthaler, D. A.

2011-12-01

37

Copyright 2004, Intel Corporation, All rights reserved. Place Lab: Device Positioning Using Radio Beacons in the Wild  

E-print Network

Copyright 2004, Intel Corporation, All rights reserved. Place Lab: Device Positioning Using Radio;Place Lab: Device Positioning Using Radio Beacons in the Wild Anthony LaMarca1 , Yatin Chawathe1 , Sunny. Location awareness is an important capability for mobile computing. Yet inexpensive, pervasive positioning

Chawathe, Yatin

38

Satellite measurements of the HF radio environment in the topside ionosphere  

Microsoft Academic Search

Measurements made on board the orbiting Air Force meteorological satellite equipped with a high-frequency (HF) receiver have been studied in order to describe the HF radio environment at the satellite height. The satellite is in a sun-synchronous dawn-dusk orbit at a height of nearly 500 nmi (860 km) above the surface on the earth. The receiver sweeps repeatedly through the

C. M. Rush; A. L. Snyder; E. Ziemba; V. Patterson; T. Tascione; D. Nelson

1980-01-01

39

Mobile radio alternative systems study satellite/terrestrial (hybrid) systems concepts  

NASA Astrophysics Data System (ADS)

The use of satellites for mobile radio service in non-urban areas of the United States in the years from 1985 to 2000 was investigated. Several satellite concepts are considered: a system with single-beam coverage of the fifty United States and Puerto Rico, and multi-beam satellites with greater capacity. All of the needed functions and services identified in the market study are provided by the satellite systems, including nationwide radio access to vehicles without knowledge of vehicle location wideband data transmission from remote sites, two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The costs of providing the services are within acceptable limits, and the desired returns to the system investors are attractive. The criteria by which the Federal Communication judges the competing demands for public radio spectrum are reviewed with comments on how the criteria might apply to the consideration of land mobile satellites. Institutional arrangements for operating a mobile satellite system are based on the present institutional arrangements in which the services are offered to the end users through wireline and radio common carriers, with direct access by large private and government users.

Kiesling, J. D.; Anderson, R. E.

1983-06-01

40

Mobile radio alternative systems study satellite/terrestrial (hybrid) systems concepts  

NASA Technical Reports Server (NTRS)

The use of satellites for mobile radio service in non-urban areas of the United States in the years from 1985 to 2000 was investigated. Several satellite concepts are considered: a system with single-beam coverage of the fifty United States and Puerto Rico, and multi-beam satellites with greater capacity. All of the needed functions and services identified in the market study are provided by the satellite systems, including nationwide radio access to vehicles without knowledge of vehicle location wideband data transmission from remote sites, two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The costs of providing the services are within acceptable limits, and the desired returns to the system investors are attractive. The criteria by which the Federal Communication judges the competing demands for public radio spectrum are reviewed with comments on how the criteria might apply to the consideration of land mobile satellites. Institutional arrangements for operating a mobile satellite system are based on the present institutional arrangements in which the services are offered to the end users through wireline and radio common carriers, with direct access by large private and government users.

Kiesling, J. D.; Anderson, R. E.

1983-01-01

41

Ionospheric models for satellite and ground radio communication systems  

Microsoft Academic Search

Several empirical bottomside ionospheric models of electron density distribution with height are briefly reviewed. These include Nisbet's model (1971), the model of Bradley and Dudeney (1973), and the model of Rush and Miller (1974). Bent's global electron density model (1972) is also examined, and its application to VLBI, ground and satellite communications, and satellite orbit determination, is described.

Z. Klos; K. Stasiewicz; I. Stanislawska

1979-01-01

42

Satellite-aided mobile radio concepts study: Concept definition of a satellite-aided mobile and personal radio communication system  

NASA Technical Reports Server (NTRS)

The satellite system requires the use of a large satellite antenna and spacecraft array power of about 12 kW or more depending on the operating frequency. Technology developments needed include large offset reflector multibeam antennas, satellite electrical power sybsystems providing greater than 12 kW of power, signal switching hardware, and linearized efficient solid state amplifiers for the satellite-aided mobile band. Presently there is no frequency assignment for this service, and it is recommended that an allocation be pursued. The satellite system appears to be within reasonable extrapolation of the state of the art. It is further recommended that the satellite-aided system spacecraft definition studies and supporting technology development be initiated.

Anderson, R. E.

1979-01-01

43

CME-Associated Radio Bursts from Satellite Observations  

NASA Technical Reports Server (NTRS)

Coronal mass ejections (CMEs) are closely associated with various types of radio bursts from the Sun. All radio bursts are due to nonthermal electrons, which are accelerated during the eruption of CMEs. Radio bursts at frequencies below about 15 MHz are of particular interest because they are associated with energetic CMEs that contribute to severe space weather. The low-frequency bursts need to be observed primarily from space because of the ionospheric cutoff. The main CME-related radio bursts are associated are: type III bursts due to accelerated electrons propagating along open magnetic field lines, type II bursts due to electrons accelerated in shocks, and type IV bursts due to electrons trapped in post-eruption arcades behind CMEs. This paper presents a summary of results obtained during solar cycle 23 primarily using the white-light coronagraphic observations from the Solar Heliospheric Observatory (SOHO) and the WAVES experiment on board Wind. Particular emphasis will be placed on what we can learn about particle acceleration in the coronal and interplanetary medium by analyzing the CMEs and the associated radio bursts.

Gopalswamy, Nat

2012-01-01

44

Radio frequency interference prediction with application to satellite earth station site selection and co-ordination  

NASA Astrophysics Data System (ADS)

Until recent times, all Intelsat satellite earth stations in Australia were located in areas remote from the capital cities that are the major sources of international telecommunications traffic. High operating costs and long terrestrial tails that impeded the introduction of new services generated a need for new sites near urban centers. The main obstacle to the selection of such sites is radio frequency interference from or to the well established terrestrial radio-relay network in shared frequency bands. This paper describes the development of Australian expertise in radio-frequency interference prediction and its successful application to the selection and frequency coordination of sites near Sydney, Melbourne and Perth.

Abbasi, R. O.

45

The Faraday Fading of Radio Waves from an Artificial Satellite  

Microsoft Academic Search

Faraday fading of signals from an artificial satellite is analyzed in terms of the dif- ference between the Doppler shifts of the ordinary and extraordina .ry components in the iono- sphere. A procedure is outlined for determining the vertical distribution of electron density in the upper ionosphere. F, xplanations are given for the apparently excessive values of electron content yielded

F. H. Hibberd

1959-01-01

46

Conversion of a 30-m former satellite communications antenna to a radio telescope  

Microsoft Academic Search

A class of large satellite communication antennas built in the mid-1970's comprise a potential set of large antennas available for use by radio astronomers upon upgrade. With the advent of low noise technology these facilities have been superseded in the communications industry by smaller, more manageable facilities. Although many have sat idle and decaying over the intervening years, these facilities

David R. Deboer; Paul G. Steffes; John M. Glowacki

1998-01-01

47

Instrumentation for Spacecraft-to-Spacecraft Radio Science Observations of Jupiter and Satellites  

Microsoft Academic Search

Investigations of planetary atmospheres and surfaces via radio occultation and scattering techniques have been successfully conducted on many planets and several large satellites in the solar system using one-way downlink from a spacecraft to a ground station. Limitations on the received SNR or geometrical coverage can be overcome with alternate observation configurations. Uplink observations where a signal is transmitted from

Sami Asmar; W. Folkner; D. Hinson; L. Iess; I. Linscott; E. Marouf; P. Tortora

2010-01-01

48

Femto-Satellite system for radio-occultation study of the Ionosphere  

NASA Astrophysics Data System (ADS)

This research project proposes the use of (a swarm of) Femto-Satellites in the study of Ionospheric properties using \\underline{Radio-Occultation} techniques. It makes use of GPS signals, a computing system, tiny on-board components and a data transfer module. This project is being done as a cheaper and lightweight alternative proposal to the higher cost, already running COSMIC program and other programs which use larger satellites to perform Radio-Occultation study of the Ionosphere. Being that these femto-satellites are capable of acting as a constellation, they will be able to provide higher accuracy radio-occultation readings of the Ionosphere due to the close proximity between each satellite positioned in low earth orbit. Important parameters attempted for this system include a weight of 100 grams per satellite system and an innovative power source using solar sails. The sails also serve to provide an anti-debris system of redundancy to make sure these tiny satellites don't add to the already alarming amount of space debris, in the event of a malfunction. Ultimately, having a large amount of tiny satellites serving to study the ionosphere at closer proximities and obtain more accurate results will give the scientific community a better understanding of the constant changes in the space environment at a given altitude. This could help humanity combat adverse changes in climate, which heavily affects some regions of agriculture. This could also help advance the scientific campaign against global warming, by providing real-time readings from different regions of the ionosphere.

Savio Bradford, Brandon; Gutierrez Cabello, Jordi

49

Radio sky mapping from satellites at very low frequencies  

NASA Technical Reports Server (NTRS)

Wave Distribution Function (WDF) analysis is a procedure for making sky maps of the sources of natural electromagnetic waves in space plasmas, given local measurements of some or all of the three magnetic and three electric field components. The work that still needs to be done on this subject includes solving basic methodological problems, translating the solution into efficient algorithms, and embodying the algorithms in computer software. One important scientific use of WDF analysis is to identify the mode of origin of plasmaspheric hiss. Some of the data from the Japanese satellite Akebono (EXOS D) are likely to be suitable for this purpose.

Storey, L. R. O.

1991-01-01

50

Phase and pattern calibration of the Jicamarca Radio Observatory radar using satellites  

NASA Astrophysics Data System (ADS)

The Jicamarca Radio Observatory (JRO) main 50-MHz array antenna radar system with multiple receivers is being used to study meteors via two interferometric receiving modes. One of the major challenges in these studies is the phase calibration of the various receiver (interferometric) channels (legs). While investigating some ambiguous features in meteor head-echo results, we developed a `new' calibration technique that employs satellite observations to produce more accurate phase and pattern measurements than were previously available. This calibration technique, which resolves head-echo ambiguities, uses the fact that Earth-orbiting satellites are in gravitationally well-defined orbits and thus the pulse-to-pulse radar returns must be consistent (coherent) for an entire satellite pass through the radar beam. In particular, the satellite yields a reliable point source for phase and thus interferometry-derived range, Doppler and trajectory calibration. Using several satellites observed during standard meteor observations, we derive satellite orbital parameters by matching the observed and modelled three-dimensional trajectory and Doppler results. This approach uncovered subtle phase distortions that led to interferometry-derived trajectory distortions that are important only to point targets such as meteor head-echoes. We present the array calibration and radar imaging of satellite passes from our meteor observations of 2010 April 15/16. Future observations of a priori known satellites would likely yield significantly more accurate calibrations, especially of distant side lobes.

Gao, B.; Mathews, J. D.

2015-02-01

51

Channel and Traffic based Adaptive Radio Resource Management strategies for the return link of Ka\\/Q\\/V band Communication Satellite systems employing Fade Mitigation Techniques  

Microsoft Academic Search

Efficient utilization of the satellite radio resource is of paramount importance to a satellite system's performance and economic competitiveness. The likely use of Ka band and above frequencies for future satellite systems and the need for a better quality of service (QoS) complicate the radio resource management process especially in the return link of a satellite system, one that connects

A. Aroumont; J. Radzik; M. Bousquet; L. Castanet

2007-01-01

52

Prospects for Lunar Satellite Detection of Radio Pulses from Ultrahigh Energy Neutrinos Interacting with the Moon  

E-print Network

The Moon provides a huge effective detector volume for ultrahigh energy cosmic neutrinos, which generate coherent radio pulses in the lunar surface layer due to the Askaryan effect. In light of presently considered lunar missions, we propose radio measurements from a Moon-orbiting satellite. First systematic Monte Carlo simulations demonstrate the detectability of Askaryan pulses from neutrinos with energies above 10^{20} eV, i.e. near and above the interesting GZK limit, at the very low fluxes predicted in different scenarios.

O. Stl; J. E. S. Bergman; B. Thid; L. K. S. Daldorff; G. Ingelman

2007-02-15

53

Propagation measurements for satellite radio reception inside buildings  

NASA Technical Reports Server (NTRS)

Swept CW signals (from 700 to 1800 MHz) were received inside six buildings of brick, corrugated sheet-metal, wood-frame, mobile-home, and reinforced concrete-wall construction. A transmitter antenna was mounted outdoors on top of an 18 m tower to simulate a satellite, and a linearly scanned directional receiver antenna was used to probe the spatial, spectral, and temporal variability of the signal indoors. Levels were found to have much structure in the spatial and frequency domain, but were relatively stable in time. Typically, people moving nearby produced variations of less than 0.5 dB, whereas a person blocking the transmission path produced fades of 6 to 10 dB. Severe losses (17.5 dB) were observed in the concrete-wall building, which also exhibited the longest multipath delays (over 100 ns). Losses inside a mobile home were even larger (over 20 dB) and were independent of antenna orientation. The power-frequency distortion increased with the logarithm of the bandwidth, but could be reduced by moving to a position of higher power. Only the losses showed a clear frequency dependence, but they could be mitigated by moving the antenna.

Vogel, Wolfhard J.; Torrence, Geoffrey W.

1993-01-01

54

Analysis of type 3 solar radio bursts observed at kilometric wavelengths from the OGO-5 satellite  

NASA Technical Reports Server (NTRS)

Research was conducted to analyze the data on solar radio bursts obtained by the OGO-5 satellite. Since the wavelengths corresponding to the three lowest frequencies of observations exceeded one kilometer, the bursts detected in those channels were designated as kilometer-waves. The data search covered approximately 9200 hours between March 1968 and February 1970, and included the maximum of solar cycle No. 20. The study concentrated on 64 Type 3 solar radio events reaching frequencies equal or lower than 0.35 MHz. This selection criteria led to the choice of the most intense radio events. Measurements included: times of start, times of decay, and amplitudes of the 64 events. The consistency of the results, within the accuracy of the measurements, lends support to some of the assumptions made for the analysis, notably, the validity of the local plasma hypothesis, the constancy of the exciter particles velocity, and spiral shape of their trajectory.

Alvarez, H.

1971-01-01

55

Digital Radio Broadcasting using the mixed satellite/terrestrial approach: An application study  

NASA Technical Reports Server (NTRS)

Digital radio broadcasting (DRB) is a new service that offers CD quality stereo programs to fixed, portable and mobile receivers. Terrestrial DRB in Canada is considered as a replacement technology for existing AM and FM services, and it is expected to start up in 1996. Canada currently favors Eureka 147 technology operating in the L-band, in the 1452-1492 MHz frequency band allocated during WARC'92 for DRB. Terrestrial DRB delivery is appropriate for small to medium sized service areas, such as cities and their associated suburbs. For larger areas such as provinces, as well as for sparsely populated areas such as the regions in northern Canada, satellite delivery is more appropriate. The mixed approach is based on both satellite and terrestrial broadcasting services using a common frequency band. Spectrum efficiency is achieved through close coordination of both service types, to achieve proper frequency sharing and spectrum re-use. As well, use of a common transmission format by both types of services allows for a common receiver. This mixed satellite/terrestrial approach to DRB is being seriously considered in Canada and in other countries. This paper studies the feasibility of such a mixed satellite/terrestrial DRB system. It looks at possible coverage scenarios for Canada, and at the satellite and receiver technology requirements.

Paiement, Richard V.; Voyer, Rene; Prendergast, Doug

1995-01-01

56

The Italian Radio Occultation experiment on-board the Indian OCEANSAT-2 satellite  

NASA Astrophysics Data System (ADS)

During the June 2007 the Indian satellite OCEANSAT-2 will be launched The Italian Space Agency ASI signed a Memorandum of Understandings with the Indian Space Research Organization ISRO in which it is agreed to put on-board the OCEANSAT-2 satellite the Italian GNSS receiver devoted to Radio Occultation ROSA - Radio Occultation Sounder of the Atmosphere In the framework of this mission this instrument can only be able to observe rising occultations the Radio Occultation antenna will be mounted on the aft-velocity direction collecting data both in Open-Loop and in Close-Loop modes These data will be downloaded to the Indian and the Italian receiving stations where they will be processed by the ROSA ground segment completely developed by Italian universities and research centres In particular this ground segment will be implemented at a first level in an integrated computing infrastructure installed in Matera and mirrored at Hyderbad in India and at a second level on a distributed software and hardware infrastructure This second infrastructure will perform the rapid and precise Orbit Determination and Prediction the bending and impact parameters profiles extraction the ionospheric correction and the stratospheric initialization the refractivity pressure temperature and humidity profile retrieval the value added services for meteorology climate and space weather applications by computing units of each research centre or university connected through a Web-based GRID computing infrastructure After a description of these two

Perona, G.; Rosa Team

57

Rural land mobile radio market assessment and satellite and terrestrial system concepts  

NASA Technical Reports Server (NTRS)

The market for satellite-based mobile radio in the rural U.S. is evaluated, summarizing the results of two NASA-funded studies reported by Anderson et al. and Hornstein. The study aims are listed, and the results are presented in tables, graphs, and maps and discussed. Space systems are found to be competitive with land-based systems, providing superior service at lower subscriber charges, but having limited compatibility with urban cellular mobile-radio systems. Of the three system concepts evaluated from a technological standpoint (direct-to-mobile, mobile-translator, and hybrid), the mobile-translator concept is considered most cost effective, at least within the constraints assumed in the study.

Stevenson, S.; Provencher, C.

1984-01-01

58

Adaptive sparse signal processing of satellite-based radio frequency (RF) recordings of lightning events  

NASA Astrophysics Data System (ADS)

Ongoing research at Los Alamos National Laboratory studies the Earth's radio frequency (RF) background utilizing satellite-based RF observations of terrestrial lightning. Such impulsive events are dispersed through the ionosphere and appear as broadband nonlinear chirps at a receiver on-orbit. They occur in the presence of additive noise and structured clutter, making their classification challenging. The Fast On-orbit Recording of Transient Events (FORTE) satellite provided a rich RF lightning database. Application of modern pattern recognition techniques to this database may further lightning research in the scientific community, and potentially improve on-orbit processing and event discrimination capabilities for future satellite payloads. Conventional feature extraction techniques using analytical dictionaries, such as a short-time Fourier basis or wavelets, are not comprehensively suitable for analyzing the broadband RF pulses under consideration here. We explore an alternative approach based on non-analytical dictionaries learned directly from data, and extend two dictionary learning algorithms, K-SVD and Hebbian, for use with satellite RF data. Both algorithms allow us to learn features without relying on analytical constraints or additional knowledge about the expected signal characteristics. We then use a pursuit search over the learned dictionaries to generate sparse classification features, and discuss their performance in terms of event classification. We also use principal component analysis to analyze and compare the respective learned dictionary spaces to the real data space.

Moody, Daniela I.; Smith, David A.

2014-05-01

59

The evolution of satellite-monitored radio tags for large whales: One laboratory's experience  

NASA Astrophysics Data System (ADS)

Despite several centuries of whaling and directed research, there are only a few whale stocks whose year-round whereabouts are reasonably well known. For the vast majority of depleted populations, the link between seasonal feeding and breeding concentrations remains unknown. This lack of information on range, seasonal distribution, stock structure, and migration routes makes it difficult to design and implement effective conservation measures to promote recovery. The use of such information would have been valuable to develop stock-specific quotas for whaling, but now it may be even more important for recovery of depleted stocks and identifying anthropogenic threats throughout a depleted stock's range. Building upon the preliminary findings of Discovery tags and more recent photo identification studies, satellite-monitored radio tags are now providing range and seasonal distribution information for many stocks of depleted large whales. These parameters are important to better estimate population abundance, characterize habitats, identify threats to recovery, and design effective protection measures when needed. This paper traces one laboratory's experience with the development of satellite-monitored radio tag technology for large whales, including attachment mechanisms and delivery systems, in the hope that others will profit from our successes and our mistakes. Selected examples are used to demonstrate how such tags contribute to new insights about whales' habitats, migrations, behaviour, and management.

Mate, Bruce; Mesecar, Roderick; Lagerquist, Barbara

2007-02-01

60

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

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

61

Refractivity and temperature climate records from multiple radio occultation satellites consistent within 0.05%  

NASA Astrophysics Data System (ADS)

Data consistency is an important prerequisite to build radio occultation (RO) climatologies based on a combined record of data from different satellites. The presence of multiple RO receiving satellites in orbit over the same time period allows for testing this consistency. We used RO data from CHAMP (CHAllenging Minisatellite Payload for geoscientific research), six FORMOSAT-3/COSMIC satellites (Formosa Satellite Mission 3/Constellation Observing System for Meteorology, Ionosphere and Climate, F3C), and GRACE-A (Gravity Recovery and Climate Experiment). We show latitude-altitude-resolved results for an example month (October 2007) and the temporal evolution of differences in a climate record of global and monthly means from January 2007 to December 2009. Latitude- and altitude-resolved refractivity and dry temperature climatologies clearly show the influence of different sampling characteristics; monthly mean deviations from the multi-satellite mean over the altitude domain 10 km to 30 km typically reach 0.1% and 0.2 K, respectively. Nevertheless, the 3-year average deviations (shorter for CHAMP) are less than 0.03% and 0.05 K, respectively. We find no indications for instrument degradation, instationarities in the RO records, or temporal trends in sampling patterns. Based on analysis fields from ECMWF (European Centre for Medium-Range Weather Forecasts), we can estimate - and subtract - the sampling error from each monthly climatology. After such subtraction, refractivity deviations are found reduced to <0.05% in almost any month and dry temperature deviations to <0.05 K (<0.02% relative) for almost every satellite and month. 3-year average deviations are even reduced to <0.01% and <0.01 K (CHAMP: -0.05 K), respectively, establishing an amazing consistency of RO climatologies from different satellites. If applying the same processing scheme for all data, refractivity and dry temperature records from individual satellites with similar bending angle noise can be safely combined up to 30 km altitude (refractivity also up to 35 km) to a consistent single climate record of substantial value for climate monitoring in the upper troposphere and lower stratosphere.

Foelsche, U.; Scherllin-Pirscher, B.; Ladstdter, F.; Steiner, A. K.; Kirchengast, G.

2011-03-01

62

Refractivity and temperature climate records from multiple radio occultation satellites consistent within 0.05%  

NASA Astrophysics Data System (ADS)

Data consistency is an important prerequisite to build radio occultation (RO) climatologies based on a combined record of data from different satellites. The presence of multiple RO receiving satellites in orbit over the same time period allows for testing this consistency. We used RO data from CHAMP (CHAllenging Minisatellite Payload for geoscientific research), six FORMOSAT-3/COSMIC satellites (Formosa Satellite Mission 3/Constellation Observing System for Meteorology, Ionosphere and Climate, F3C), and GRACE-A (Gravity Recovery and Climate Experiment). We show latitude-altitude-resolved results for an example month (October 2007) and the temporal evolution of differences in a climate record of global and monthly means from January 2007 to December 2009. Latitude- and altitude-resolved refractivity and dry temperature climatologies clearly show the influence of different sampling characteristics; monthly mean deviations from the multi-satellite mean over the altitude domain 10 km to 30 km typically reach 0.1% and 0.2 K, respectively. Nevertheless, the 3-yr average deviations (shorter for CHAMP) are less than 0.03% and 0.05 K, respectively. We find no indications for instrument degradation, temporal inhomogeneities in the RO records, or temporal trends in sampling patterns. Based on analysis fields from ECMWF (European Centre for Medium-Range Weather Forecasts), we can estimate - and subtract - the sampling error from each monthly climatology. After such subtraction, refractivity deviations are found reduced to <0.05% in almost any month and dry temperature deviations to <0.05 K (<0.02% relative) for almost every satellite and month. 3-yr average deviations are even reduced to <0.01% and <0.01 K (CHAMP: -0.05 K), respectively, establishing an amazing consistency of RO climatologies from different satellites. If applying the same processing scheme for all data, refractivity and dry temperature records from individual satellites with similar bending angle noise can be safely combined up to 30 km altitude (refractivity also up to 35 km) to a consistent single climate record of substantial value for climate monitoring in the upper troposphere and lower stratosphere.

Foelsche, U.; Scherllin-Pirscher, B.; Ladstdter, F.; Steiner, A. K.; Kirchengast, G.

2011-09-01

63

Voyager 2 radio science observations of the uranian system: atmosphere, rings, and satellites.  

PubMed

Voyager 2 radio occultation measurements of the Uranian atmosphere were obtained between 2 and 7 degrees south latitude. Initial atmospheric temperature profiles extend from pressures of 10 to 900 millibars over a height range of about 100 kilometers. Comparison of radio and infrared results yields mole fractions near the tropopause of 0.85 and 0.15 +/- 0.05 for molecular hydrogen and helium, respectively, if no other components are present; for this composition the tropopause is at about 52 kelvins and 110 millibars. Distinctive features in the signal intensity measurements for pressures above 900 millibars strongly favor model atmospheres that include a cloud deck of methane ice. Modeling of the intensity measurements for the cloud region and below indicates that the cloud base is near 1,300 millibars and 81 kelvins and yields an initial methane mole fraction of about 0.02 for the deep atmosphere. Scintillations in signal intensity indicate small-scale stucture throughout the stratosphere and upper troposphere. As judged from data obtained during occultation ingress, the ionosphere consists of a multilayer structure that includes two distinct layers at 2,000 and 3,500 kilometers above the 100-millibar level and an extended topside that may reach altitudes of 10,000 kilometers or more. Occultation measurements of the nine previously known rings at wavelengths of 3.6 and 13 centimeters show characteristic values of optical depth between about 0.8 and 8; the maxim value occurs in the outer region of the in ring, near its periapsis. Forward-scattered signals from this ring have properties that differ from those of any of Saturn's rings, and they are inconsistent with a discrete scattering object or local (three-dimensional) assemblies of orbiting objects. These signals suggest a new kdnd of planetary ring feature characterized by highly ordered cylindrical substructures of radial scale on the order of meters and azimuthal scale of kilometers or more. From radio data alone the mass of the Uranian system is GM(sys) = 5,794,547- 60 cubic kilometers per square second; from a combination of radio and optical navigation data the mass of Uranus alone is GM(u) = 5,793,939+/- 60 cubic kilometers per square second. From all available Voyager data, induding imaging radii, the mean uncompressed density of the five major satellites is 1.40+/- 0.07 grams per cubic centimeter; this value is consistent with a solar mix of material and apparently rules out a cometary origin of the satellites. PMID:17812893

Tyler, G L; Sweetnam, D N; Anderson, J D; Campbell, J K; Eshleman, V R; Hinson, D P; Levy, G S; Lindal, G F; Marouf, E A; Simpson, R A

1986-07-01

64

The Plasma Environments of Jupiter's Galilean Satellites - Galileo Radio Science Results  

NASA Astrophysics Data System (ADS)

The Galileo spacecraft has been orbiting Jupiter since 1995. During that time it has provided several opportunities for the study of the plasma environments of the Galilean satellites Io,Europa, Ganymede, and Callisto by means of radio occultation of its S-band (13.5 cm. wavelength) signal. There have been five occultations each by Io, Europa, Ganymede, and Callisto, however, one of the Ganymede and one of the Callisto occultations occurred near superior conjunction, and did not provide useful data. When observed, the maximum electron densities range from about 5 to about 20x103 cm-3 . The apparent vertical structure of these plasma layers range from classical ionospheric profiles observed at Callisto on two occasions to multi-peaked structures observed at Europa. On several occasions no discernible plasma was observed. These observations could be explained by a process in which a tenuous neutral atmosphere ( about 1010 cm-3 is created on the trailing hemisphere by sputtering from the icy surface by energetic particles of the Jovian magnetosphere. If the trailing hemisphere is also illuminated by the Sun, plasma is produced by photoionization and is observed by radio occultation. The configuration of this plasma is, however, determined by its interaction with the corotating Jovian magnetospheric plasma, which under certain geometries would lead to the observation of multipeaked structures.

Kliore, A. J.

2003-12-01

65

Airborne Remote Observations of L-Band Radio Frequency Interference and Implications for Satellite Missions  

NASA Technical Reports Server (NTRS)

Passive remote sensing of the Earth s surface and atmosphere from space has significant importance in operational and research environmental studies, in particular for the scientific understanding, monitoring and prediction of climate change and its impacts. Passive remote sensing requires the measurement of naturally occurring radiations, usually of very low power levels, which contain essential information on the physical process under investigation. As such, these sensed radio frequency bands are a unique natural resource enabling space borne passive sensing of the atmosphere and the Earth s surface that deserves adequate allocation to the Earth Exploration Satellite Service and absolute protection from interference. Unfortunately, radio frequency interference (RFI) is an increasing problem for Earth remote sensing, particularly for passive observations of natural emissions. Because these natural signals tend to be very weak, even low levels of interference received by a passive sensor may degrade the fidelity of scientific data. The characteristics of RFI (low-level interference and radar-pulse noise) are not well known because there has been no systematic surveillance, spectrum inventory or mapping of RFI. While conducting a flight experiment over central Tennessee in May 2010, RFI, a concern for any instrument operating in the passive L band frequency, was observed across 16 subbands between 1402-1427 MHz. Such a survey provides rare characterization data from which to further develop mitigation technologies as well as to identify bandwidths to avoid in future sensor formulation.

Laymon, Charles; Srinivasan, Karthik; Limaye, Ashutosh

2011-01-01

66

Overview of Cassini radio science at Saturn, Titan, and the icy satellites  

NASA Astrophysics Data System (ADS)

The Cassini spacecraft which has been in orbit about Saturn for over two years is the first Radio Science platform to provide three downlink frequencies In addition to the X-band telemetry link 3 56 cm w l two other frequencies S-band 13 04 cm and Ka-band 0 94 cm are available This plus the high SNR 50 dBHz at X-band afforded by the 4 m diameter s c high gain antenna in combination with the excellent low noise receivers of the DSN as well as overall system stabilities of 1 part in 10 13 when referenced to the on-board ultra-stable oscillator USO in one-way operation and 1 part inx 10 15 for a two-way link make Cassini an unprecedented instrument of radio science The orbital tour phase of the mission has the following main radio science objectives a determination of the masses and gravity fields of Saturn s icy satellites Titan and Saturn through two-way tracking during fly-bys To date the masses of Phoebe Iapetus Dione Enceladus Rhea and Titan have been measured and will be reported here b Measurement of the structure and other properties of Saturn s rings through three-band occultation Seven near-diametric occultations at a high ring opening angle have been completed and the results will be presented here c Measurement of the vertical structure of the atmosphere and ionosphere of Saturn The same series of occultations have provided nearly equatorial observations of the atmosphere structure and the ionosphere and the results will be described here d Measurement of the vertical structure of

Kliore, A. J.; Ambrosini, R.; Armstrong, J. W.; Flasar, F. M.; French, R. G.; Iess, L.; Marouf, E. A..; Nagy, A. F.; Rappaport, N. J.; Tortora, P.; Jpl/Dsn Radio Science Support Team

67

Did the walls have ears? -Background Briefing -ABC Radio National (Australian Broadcasting Corporation) http://www.abc.net.au/radionational/programs/backgroundbriefing/2014-02-23/5267456[25/02/2014 12:02:07 PM  

E-print Network

have ears? - Background Briefing - ABC Radio National (Australian Broadcasting Corporation) http://www.abc.net.au/radionational/programsDid the walls have ears? - Background Briefing - ABC Radio National (Australian Broadcasting Corporation) http://www.abc.net.au/radionational/programs/backgroundbriefing/2014-02-23/5267456[25/02/2014 12

68

Direct Broadcast Satellites: An Interview with Hartford Gunn.  

ERIC Educational Resources Information Center

In this interview with Hartford Gunn, Vice-President of Program Development for Satellite Television Corporation (STC), the concept of direct broadcast by satellite (DBS) is explored. Allocation of radio frequencies, services provided by DBS network, home installation and purchase of dish antenna, and comparison of DBS with cable television are

Library Hi Tech, 1984

1984-01-01

69

Monitoring the Atmospheric Boundary Layer by Radio Occultation Signals Recorded by COSMIC Satellites  

NASA Astrophysics Data System (ADS)

The Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) uses radio occultation (RO) observations of the Global Positioning System (GPS) satellites to retrieve vertical profiles of the bending angle and refractivity in the atmosphere. Unlike previous RO missions utilizing the phase-locked loop (PLL) signal tracking technique, COSMIC receivers record L1 GPS signals in open-loop (OL) mode in the lowest 10 km of the troposphere by allowing penetration of the retrieved profiles down to the ocean surface. This provides an opportunity for monitoring the atmospheric boundary layer (ABL) with high vertical resolution (50-100 m), not available from other satellite data and not generally possible with PLL RO data from previous RO missions due to insufficient penetration and tracking errors. The optimal way of utilizing information about the ABL from RO observations is direct assimilation of the inverted bending angle and refractivity profiles into atmospheric models with sufficiently high vertical resolution in the lower troposphere. Alternatively, estimates of the depth of the ABL, which is an important parameter for meteorology and climatology, can be extracted from the structure of RO signals and inverted profiles. Such methods and results of their application to COSMIC RO data will be discussed.

Sokolovskiy, S.; Kuo, Y.; Rocken, C.; Schreiner, W.; Hunt, D.; Anthes, R.; Lenschow, D.

2006-12-01

70

Overview of techniques for mitigation of fading and shadowing in the direct broadcast satellite radio environment  

NASA Technical Reports Server (NTRS)

The DBS radio propagation environment is divided into three sub-environments, indoor, rural-suburban mobile and urban mobile. Indoor propagation effects are in a large part determined by construction material. Non-metallic materials afford direct, albeit attenuated penetration of the satellite signal with a minimum of multipath signal scattering. Signal penetration into structures using significant metallic materials is often indirect, through openings such as doors and windows and propagation will involve significant multipath components. Even so, delay spread in many situations is on the order of 10's of nanoseconds resulting in relatively flat fading. Thus frequency diversity techniques such as Orthogonal Frequency Division Multiplex (OFDM) and Code Division Multiple Access (CDMA) or equalization techniques do not realize their intended performance enhancement. Antenna diversity, directivity and placement are key mitigation techniques for the indoor environment. In the Rural-Suburban mobile environment with elevation angles greater than 20 deg, multipath components from the satellite signal are 15-20 dB below the line-of-sight signal level and often originate from nearby reflectors. Thus shadowing is the dominant signal impairment and fading effects are again found to be relatively flat for a large fading margin. Because receiver motion induces rapid variations in the signal level, temporal diversity techniques such as interleaving, channel coding and retransmission can be used to combat short intermittent fading events. Antenna diversity and directivity techniques are again useful in this environment. Finally, in the Urban mobile environment, slower vehicle speeds and blockage by buildings causes signal fades that are too long and too deep to combat with signal margin or time diversity. Land-based signal boosters are needed to fill in the coverage gaps of the satellite only broadcast scheme. On frequency boosters are suggested to conserve bandwidth yet these produce long delay multipath and create a frequency selective fading environment. Enter now OFDM, spread spectrum, equalization and other techniques that are capable of deconvolving the channel effects and effecting significant performance improvements by extracting the frequency diversity or time diversity components comprising the received signal.

Bell, David; Gevargiz, John; Vaisnys, Arvydas; Julian, David

1995-01-01

71

Product amount and quality monitoring in agricultural fields with remote sensing satellite and radio-control helicopter  

NASA Astrophysics Data System (ADS)

Product amount and quality monitoring in agricultural fields with remote sensing satellite and radio-control helicopter is proposed. In particular, tealeaves and rice crop quality and amoujnt monitorings are peoposed as examples. Nitrogen rich tealeaves tasts good. Therefore, quality of tealeaves can be estimated with nitrogen content which is related with near infrared reflectance of the tealeves in concern. Also, rice crop quality depends on protein content in rice grain which is related to near infrared reflectance of rice leaves. Therefore, product quality can be estimated with observation of near infrared reflectance of the leaves in concern. Near infared reflectance is provided by near infrared radiometers onboard remote sensing satellites and by near infrared cameras onboard radio-control helicopter. This monitoring system is applicable to the other agricultural plant products. Through monitoring near ingfrared reflectance, it is possible to estimate quality as well as product amount.

Arai, Kohei

72

An experimental investigation of the power spectrum of phase modulation induced on a satellite radio signal by the ionosphere  

NASA Technical Reports Server (NTRS)

The power spectrum of phase modulation imposed upon satellite radio signals by the inhomogeneous F-region of the ionosphere (100 - 500 km) was studied. Tapes of the S-66 Beacon B Satellite recorded during the period 1964 - 1966 were processed to yield or record the frequency of modulation induced on the signals by ionospheric dispersion. This modulation is produced from the sweeping across the receiving station as the satellite transits of the two dimensional spatial phase pattern are produced on the ground. From this a power spectrum of structure sizes comprising the diffracting mechanism was determined using digital techniques. Fresnel oscillations were observed and analyzed along with some comments on the statistical stationarity of the shape of the power spectrum observed.

Moser, D. T.

1972-01-01

73

Conversion of a 30-m former satellite communications antenna to a radio telescope  

NASA Astrophysics Data System (ADS)

A class of large satellite communication antennas built in the mid-1970's comprise a potential set of large antennas available for use by radio astronomers upon upgrade. With the advent of low noise technology these facilities have been superseded in the communications industry by smaller, more manageable facilities. Although many have sat idle and decaying over the intervening years, these facilities remain a potential resource for research and education. A pair of such dishes has been acquired by Georgia Tech and one of the 30 meter antennas has been completely mechanically and electrically stripped and new mechanical, control, RF, and electrical systems installed. The antenna is now driven by four continuous-speed vector-controlled three-phase AC induction motors with variable frequency vector motor drives. Sixteen bit resolution optical absolute position encoders on each axis provide telescope pointing data. Sixteen bit resolution optical absolute position encoders on each axis provide telescope pointing data. A programmable logic controller provides interlock monitoring and control. The antenna is controllable both manually via a portable remote control unit and via a Pentium PC running control software on a real-time UNIX-based platform. The manual unit allows limited control at two user-selectable speeds while computer control allows full tracking capability with accuracies of better than 0.3 arcminutes. The facility can be remotely controlled via the internet, although currently only a dedicated line is used. The antenna has been refitted with an ultra-broadband feed system capable of operating from 1-7 GHz.

Deboer, David R.; Steffes, Paul G.; Glowacki, John M.

1998-05-01

74

Predictions of HF system performance for propagation through disturbed ionospheres measured using low-Earth-orbit satellite radio beacon tomography  

NASA Astrophysics Data System (ADS)

CERTO radio beacon on the C/NOFS satellite sends VHF/UHF radio signals at 150 and 400 MHz to provide measurements of integrated electron density or Total Electron Content (TEC) by an east-west chain of ground receivers in Peru. Computerized Ionospheric Tomography (CIT) is used to convert the TEC data into two-dimensional images of electron densities with maximum 5 5 km resolution in Longitude-Altitude space. These images are updated every 95 min as the C/NOFS satellite passes over the receiver network in its low-latitude orbit with an inclination of 12. The 2-D, high-resolution images of the ionosphere are used to predict the impact of equatorial plasma structures on HF propagation of radar and radio signals. Electron density measurements from the NRL radio tomography chain across Peru are used for simulations of the performance by HF one-way links. HF rays from transmitter to receiver are traced through the electron density images produced by radio beacon tomography. Eight separate paths are found between a transmitter and ground receiver separated by 2000 km. A total of 36 backscatter echoes are found with unique group delay, Doppler frequency shift, phase delay, and echo amplitude. This multipath effect explains the range and Doppler spreading of observations for HF monostatic radar propagation through F layer irregularities. This type of analysis is useful for prediction and interpretation of range and Doppler observations from HF systems including over-the-horizon and SuperDARN radars, HF Geolocation Arrays, and HF communications networks.

Bernhardt, Paul A.; Hei, Matthew A.; Siefring, Carl L.; Wilkens, Matthew R.

2014-07-01

75

Hybrid system of communication and radio determination using two geostationary satellites  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

76

Radio resource management across multiple protocol layers in satellite networks: a tutorial overview  

Microsoft Academic Search

SUMMARY Satellite transmissions have an important role in telephone communications, television broadcasting, computer communications, maritime navigation, and military command and control. Moreover, in many situations they may be the only possible communication set-up. Trends in telecommunications indicate that four major growth market\\/service areas are messaging and navigation services (wireless and satellite), mobility services (wireless and satellite), video delivery services (cable

Paolo Barsocchi; Nedo Celandroni; Franco Davoli; Erina Ferro; Giovanni Giambene; Francisco Javier Gonzlez Castao; Alberto Gotta; Jose Ignacio Moreno; Petia Todorova

2005-01-01

77

Corporate Overview August, 2010  

E-print Network

Business Description a. Satellite communications / broadcasting b. Multi-Channel Pay-TV Platform No. 1 Satellite Business in Japan and Asia ? Formerly SKY Perfect Communications Formerly JSAT & Satellite Business Group SKY Perfect JSAT Corporation #12;Copyright © 2010 Sky Perfect JSAT Corporation. All

78

Assessment of long-distance HF radio and satellite communication assets for RNLAF out-of-area operations  

NASA Astrophysics Data System (ADS)

This report presents the relative assessment of various long-haul communication systems in order to fulfill the need for communications between the rear area and Royal Netherlands Airforce (RNLAF) units deployed in out-of-area operations. Four different communication systems are compared with respect to the operational aspects: High Frequency (HF) radio communication systems; Military satellite communication (SATCOM) systems; Public access SATCOM systems (such as the INMARSAT system); Private SATCOM networks (based on the use of very small aperture terminals (VSATs)). The comparison is based on the current available communications assets. Future technical developments and their consequences for the system comparison are also discussed.

Vanaken, R.; Vanvliet, P. J.; Hoefsloot, P. Ch.

1994-09-01

79

The RadioSat (sm) network  

NASA Technical Reports Server (NTRS)

The RadioSat network under development by radio Satellite Corporation will use mobile satellite (MSAT) technology to provide diverse personal communications, broadcast, and navigation services. The network will support these services simultaneously for integrated mobile radios throughout Canada and the United States. The RadioSat network takes advantage of several technological breakthroughs, all coming to fruition by the time the first MSAT satellite is launched in 1994. The most important of these breakthroughs is the enormous radiated power of each MSAT spacecraft - orders of magnitude greater than the radiated power of previous L-band spacecraft. Another important breakthrough is the development of advanced digital audio compression algorithms, enabling the transmission of broadcast quality music at moderate data rates. Finally, continuing dramatic increases in VLSI capabilities permit the production of complex, multi-function mobile satellite radios in very large quantities at prices little more than those of conventional car radios. In addition to performance breakthroughs and their economic implications to RadioSat, the design of the RadioSat network is reviewed.

Noreen, Gary K.

1991-01-01

80

Future communications satellite applications  

NASA Technical Reports Server (NTRS)

The point of view of the research is made through the use of viewgraphs. It is suggested that future communications satellite applications will be made through switched point to point narrowband communications. Some characteristics of which are as follows: small/low cost terminals; single hop communications; voice compatible; full mesh networking; ISDN compatible; and possible limited use of full motion video. Some target applications are as follows: voice/data networks between plants and offices in a corporation; data base networking for commercial and science users; and cellular radio internodal voice/data networking.

Bagwell, James W.

1992-01-01

81

Interleaved multi-band pyramidal antennas combining radio navigation and telemetry satellite applications  

Microsoft Academic Search

We have proposed and validated through simulations the possibility to interleave two pyramidal multi-band antennas. This new design enables to overcome bandwidth limitation problems as only one trap is now needed per radiating element on the radio navigation antenna. The feeding network is simplified as the two applications are now separated and polarizations can be defined independently for the two

N. J. G. Fonseca; Cyril Mangenot; S. Hebib; H. Aubert; O. Pascal

2009-01-01

82

Impact of tropospheric scintillation in the Ku\\/K bands on the communications between two LEO satellites in a radio occultation geometry  

Microsoft Academic Search

A theoretical analysis of the impact of clear-air tropospheric scintillation on a radio occultation link between two low Earth orbit satellites in K- and Ku-bands is presented, with particular reference to differential approaches for the measure of the total content of water vapor. The troposphere is described as a spherically symmetric turbulent medium satisfying Kolmogorov theory. Rytov's first iteration solution

Enrica Martini; Angelo Freni; Luca Facheris; Fabrizio Cuccoli

2006-01-01

83

Guided radio-wave propagation in the equatorial ionosphere according to the Intercosmos-19 and Alouette/ISIS satellites  

NASA Astrophysics Data System (ADS)

In addition to normal vertical-incident ionogram traces, strongly remote (up to 2000 km), traces of HF-radio-signal reflections observed on topside-sounder ionograms of the Interkosmos-19 satellite obtained in the equatorial ionosphere are presented. Such traces are connected with waveguides (ducts). These waveguides are field-aligned irregularities of ionospheric plasma with electron density depletion of a few percent and cross-field dimension of a few to several kilometers. Ray tracing confirms this supposition and allows an estimate of the typical parameters of the waveguides. The waveguide traces usually start at the cutoff frequency of the main trace. However, sometimes they begin at much lower frequencies which indicate the waveguides are located in plasma bubbles. Only one ducted trace is usually observed on the Interkosmos-19 ionograms; a second conjugate trace is rarely recorded. Waveguides are observed at all heights of Interkosmos-19 (500-1000 km) inside the equatorial anomaly region (from -40 to +40 degrees DipLat). Ducted-echo characteristics observed with the Interkosmos-19 are different from those observed earlier with the Alouette and ISIS satellites. This difference is discussed. It is shown that the ionospheric plasma irregularities responsible for the waveguides are observed much more often during nighttime than during daytime.

Karpachev, Alexander; Zhbankov, Gennadii; Telegin, Viktor; Kuleshova, Valentina

84

GIANT LOBES OF CENTAURUS A RADIO GALAXY OBSERVED WITH THE SUZAKU X-RAY SATELLITE  

SciTech Connect

We report on Suzaku observations of selected regions within the southern giant lobe of the radio galaxy Centaurus A. In our analysis we focus on distinct X-ray features detected with the X-ray Imaging Spectrometer within the range 0.5-10 keV, some of which are likely associated with fine structure of the lobe revealed by recent high-quality radio intensity and polarization maps. With the available photon statistics, we find that the spectral properties of the detected X-ray features are equally consistent with thermal emission from hot gas with temperatures kT > 1 keV, or with a power-law radiation continuum characterized by photon indices {Gamma} {approx} 2.0 {+-} 0.5. However, the plasma parameters implied by these different models favor a synchrotron origin for the analyzed X-ray spots, indicating that a very efficient acceleration of electrons up to {approx}> 10 TeV energies is taking place within the giant structure of Centaurus A, albeit only in isolated and compact regions associated with extended and highly polarized radio filaments. We also present a detailed analysis of the diffuse X-ray emission filling the whole field of view of the instrument, resulting in a tentative detection of a soft excess component best fitted by a thermal model with a temperature of kT {approx} 0.5 keV. The exact origin of the observed excess remains uncertain, although energetic considerations point to thermal gas filling the bulk of the volume of the lobe and mixed with the non-thermal plasma, rather than to the alternative scenario involving a condensation of the hot intergalactic medium around the edges of the expanding radio structure. If correct, this would be the first detection of the thermal content of the extended lobes of a radio galaxy in X-rays. The corresponding number density of the thermal gas in such a case is n{sub g} {approx} 10{sup -4} cm{sup -3}, while its pressure appears to be in almost exact equipartition with the volume-averaged non-thermal pressure provided by the radio-emitting electrons and the lobes' magnetic field. A prominent large-scale fluctuation of the Galactic foreground emission, resulting in excess foreground X-ray emission aligned with the lobe, cannot be ruled out. Although tentative, our findings potentially imply that the structure of the extended lobes in active galaxies is likely to be highly inhomogeneous and non-uniform, with magnetic reconnection and turbulent acceleration processes continuously converting magnetic energy to internal energy of the plasma particles, leading to possibly significant spatial and temporal variations in the plasma {beta} parameter around the volume-averaged equilibrium condition {beta} {approx} 1.

Stawarz, L.; Gandhi, P.; Takahashi, T.; Takei, Y. [Institute of Space and Astronautical Science JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)] [Institute of Space and Astronautical Science JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Tanaka, Y. T.; Fukazawa, Y. [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)] [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Madejski, G. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)] [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); O'Sullivan, S. P. [Sydney Institute for Astronomy, School of Physics A28, University of Sydney, Sydney, NSW 2006 (Australia)] [Sydney Institute for Astronomy, School of Physics A28, University of Sydney, Sydney, NSW 2006 (Australia); Cheung, C. C. [National Academy of Sciences, Washington, DC 20001 (United States)] [National Academy of Sciences, Washington, DC 20001 (United States); Feain, I. J. [CSIRO Astronomy and Space Science, ATNF, P.O. Box 76, Epping, NSW 1710 (Australia)] [CSIRO Astronomy and Space Science, ATNF, P.O. Box 76, Epping, NSW 1710 (Australia); Hardcastle, M. J. [School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom)] [School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Kataoka, J.; Takeuchi, Y. [Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan)] [Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan); Ostrowski, M. [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Krakow (Poland)] [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Krakow (Poland); Reville, B. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)] [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Siemiginowska, A. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Simionescu, A.; Werner, N., E-mail: stawarz@astro.isas.jaxa.jp [KIPAC, Stanford University, 452 Lomita Mall, Stanford, CA 94305 (United States)

2013-03-20

85

Radio science data on the ionospheres of Jupiter, Saturn, and their majur satellites  

NASA Astrophysics Data System (ADS)

For Jupiter sufficient data on the structure of its ionosphere has been obtained by previous spacecraft missions to begin work on a reference ionosphere These data from radio science measurements of Galileo Voyager 1 and 2 and Pioneer 10 and 11 consist of multiple electron density profiles at different latitudes Data also exist for Io Ganymede Europa and Callisto For the Saturn system high quality ionospheric data on Saturn and Titan are being collected by Cassini but the data set will not be complete until about 2010 at which time work on reference ionospheres can begin

Kliore, A. J.; Nagy, A. F.; Flasar, F. M.; Schinder, P. J.; Hinson, D. P.

86

Coronal magnetic field and the plasma beta determined from radio and multiple satellite observations  

NASA Astrophysics Data System (ADS)

We derived the coronal magnetic field, plasma density, and temperature from the observation of polarization and intensity of radio thermal free-free emission using the Nobeyama Radioheliograph (NoRH) and extreme ultraviolet (EUV) observations. We observed a post-flare loop on the west limb on 11 April 2013. The line-of-sight magnetic field was derived from the circularly polarized free-free emission observed by NoRH. The emission measure and temperature were derived from the Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO). The derived temperature was used to estimate the emission measure from the NoRH radio free-free emission observations. The derived density from NoRH was larger than that determined using AIA, which can be explained by the fact that the low-temperature plasma is not within the temperature coverage of the AIA filters used in this study. We also discuss the other observation of the post-flare loops by the EUV Imager onboard the Solar Terrestrial Relations Observatory (STEREO), which can be used in future studies to reconstruct the coronal magnetic field strength. The derived plasma parameters and magnetic field were used to derive the plasma beta, which is a ratio between the magnetic pressure and the plasma pressure. The derived plasma beta is about 5.7 10-4 to 7.6 10-4 at the loop top region.

Iwai, Kazumasa; Shibasaki, Kiyoto; Nozawa, Satoshi; Takahashi, Takuya; Sawada, Shinpei; Kitagawa, Jun; Miyawaki, Shun; Kashiwagi, Hirotaka

2014-12-01

87

User applications unique to mobile satellites  

NASA Astrophysics Data System (ADS)

As AMSC enters the market with its mobile satellite services, it faces a sophisticated user group that has already experimented with a wide range of communications services, including cellular radio and Ku-band satellite messaging. AMSC's challenge is to define applications unique to the capabilities of its dedicated L band satellite and consistent with the provisions outlined in its FCC license. Through a carefully researched approach to its three main markets (aeronautical, land mobile, and maritime) AMSC is discovering a wellspring of interest in corporate and general aviation, trucking companies, pipeline monitoring and control companies, maritime management firms, telecommunications companies, and government agencies. A general overview is provided of AMSC's FCC license and corporate history, and the specific applications unique to each user group is discussed.

Castiel, David

88

User applications unique to mobile satellites  

NASA Technical Reports Server (NTRS)

As AMSC enters the market with its mobile satellite services, it faces a sophisticated user group that has already experimented with a wide range of communications services, including cellular radio and Ku-band satellite messaging. AMSC's challenge is to define applications unique to the capabilities of its dedicated L band satellite and consistent with the provisions outlined in its FCC license. Through a carefully researched approach to its three main markets (aeronautical, land mobile, and maritime) AMSC is discovering a wellspring of interest in corporate and general aviation, trucking companies, pipeline monitoring and control companies, maritime management firms, telecommunications companies, and government agencies. A general overview is provided of AMSC's FCC license and corporate history, and the specific applications unique to each user group is discussed.

Castiel, David

1990-01-01

89

Second-order ionospheric effects on satellite radio occultation observations and their impact on atmospheric studies  

NASA Astrophysics Data System (ADS)

This dissertation describes the development of first-of-a-kind mathematical models that both quantify higher-order ionospheric effects and their impact on Global Positioning System radio occultation (GPS/RO) data products. We develop new and innovative models to: a) remove the second-order ionospheric effect from Total Electron Content (TEC) estimations; b) quantify the second-order ionospheric delay in GPS/RO signal propagation using the Faraday phenomenon; c) quantify the vertical distribution of the first- and second-order ionospheric residual effects on GPS/RO data products; and d) retrieve improved atmospheric water vapour profiles. For the first time we combine GPS/RO measurements with space-based gravity missions to characterize the response of the GPS/RO-derived atmospheric parameters to the Earth's gravity anomalies. Independently, we implement these mathematical models in a new GPS/RO processing software package to investigate, for the first time, the impact of higher-order ionospheric residual effects on ionospheric and atmospheric products. We observe that under low solar activity, the second-order ionospheric residual effect introduces: a) slowly varying positive systematic biases of 1-3 TECU on TEC estimations as function of occultation time; b) maximum negative systematic biases of 0.35 N-units on atmospheric refractivity close to the Earth's surface; c) negative systematic biases of 0.5 K close to the Earth's surface, which decrease with altitude and above 26 km become positive, peaking at 2.0 K at 50 km and d) negative systematic biases of 0.08 mbar on the water vapour pressure. Further studies reveal that the second-order ionospheric residual effect increases non-linearly with solar variability, oscillating between +/-3 mm (at Rz12=2) and +/-15 mm (at Rz12=114), whereas its value increases with increasing latitude. The first-order ionospheric residual effect arising from the geometrical splitting of the dual-frequency GPS radiowave signals is 2-3 orders of magnitude smaller than the second-order ionospheric residual effect, with the potential of increasing in magnitude at high solar activity. A series of sensitivity studies show that the LEO velocity uncertainties affect the GPS/RO bending angle accuracy more than the Doppler shift uncertainties. Finally, we find that the Earth's gravity anomalies can introduce negative systematic biases on the atmospheric temperature profiles of up to 0.5 K close to the Earth's surface. This dissertation demonstrates the simplicity, innovation, effectiveness and importance of our proposed mathematical models on the future of GPS/RO atmospheric remote sensing.

Vergados, Panagiotis

90

Radio Horizon Distribution Variation on 108 Megacycles per Second Measured with Satellite Signals P. R. AR,NDT ArD H. SOI CHER Institute for Exploratory Research U.S. Army Electronic Research and Development Laboratory  

Microsoft Academic Search

The radio horizon of satellite signals for an observer on earth is measured with a satellite of 780-km average altitude and a beacon frequency of 108 Mc\\/s. The analyzed data consist of measurements from 29'5 orbits from July 13, 1961, to December 4, 1961. The statistical distribution of radio horizon data differs considerably from the geometric horizon and from the

Fort Monmouth

1963-01-01

91

Analysis of the Temporal Structural Function of Tropospheric Delay of Radio Waves Using Radio Measurements of the Signals from Global Navigation Satellite Systems  

NASA Astrophysics Data System (ADS)

We present the results of a three-year experimental study of propagation of decimeter radio waves in the troposphere. The time analysis of the structural function of tropospheric delay of the decimeter radio waves for the three-year measurements of the GLONASS and GPS signals in a city of Kazan is given. The tropospheric contribution to the variance of the decimeter radio-wave delay is for the first time observed to significantly differ for the variations with time scales 1 to 24 h.

Khutorov, V. E.; Teptin, G. M.

2014-11-01

92

Onboard Photo: Astronauts Use Shuttle Amateur Radio Experiment II (SAREX-II)  

NASA Technical Reports Server (NTRS)

Space Shuttle Discovery (STS-56) onboard photo of Pilot Stephen S. Oswald (wearing a headset) uses the Shuttle Amateur Radio Experiment II (SAREX-II) while sitting at the pilot's station on the forward flight deck. Oswald smiled from behind the microphone as he talks to amateur radio operators on Earth via the SAREX equipment. SAREX cables and the interface module freefloat in front of Oswald. The anterna located in the forward flight deck window is visible in the background. SAREX was established by NASA, the American Radio League/Amateur Radio Satellite Corporation and the Johnson Space Center (JSC) Amateur Radio Club to encourage public participation in the space program through a program to demonstrate the effectiveness of conducting short-wave radio transmissions between the Shuttle and ground-based radio operators at low-cost ground stations with amateur and digital techniques.

1993-01-01

93

76 FR 65472 - Review of Foreign Ownership Policies for Common Carrier and Aeronautical Radio Licensees  

Federal Register 2010, 2011, 2012, 2013

...radio service authorized (e.g., cellular radio telephone service; microwave radio service; mobile satellite service; aeronautical...g., cellular radio telephone service; microwave radio service; mobile satellite service;...

2011-10-21

94

78 FR 41314 - Review of Foreign Ownership Policies for Common Carrier and Aeronautical Radio Licensees  

Federal Register 2010, 2011, 2012, 2013

...radio service authorized (e.g., cellular radio telephone service; microwave radio service; mobile satellite service; aeronautical...g., cellular radio telephone service; microwave radio service; mobile satellite service;...

2013-07-10

95

The effect of secular resonances on the long-term orbital evolution of uncontrollable objects on satellite radio navigation systems in the MEO region  

NASA Astrophysics Data System (ADS)

We present the results of the study of long-term orbital evolution of space debris objects, formed from end-of-life space vehicles (SV) of satellite radio navigation systems in the medium Earth orbit (MEO) region. Dynamical features of the evolution of objects in this region have been studied on the basis of 20-year laser surveillance with the Etalon-1 and Etalon-2 satellites and the results of numerical simulation of the long-term evolution of operating and disposal orbits of uncontrolled GLONASS and GPS SVs. It is shown that perturbations from secular lunisolar resonances produce an eccentricity growth for orbits with inclinations chosen for navigation constellations; this significantly changes the positions of these orbits in space and results in the ingress of end-of-life objects into the area of operating SVs.

Bordovitsyna, T. V.; Tomilova, I. V.; Chuvashov, I. N.

2012-09-01

96

Satellite congestion  

NASA Astrophysics Data System (ADS)

At last count, there were more than 160 satellites in geostationary orbits, circling the earth at an altitude of 37,000 km, and according to a research review published recently by the Rand Corporation, that's already too crowded. The risk of physical collisions among satellites is small, say authors Alvin L. Hiebert and William Sollfrey, but there is an emerging problem with what they call spectral and orbital congestion, the result of too many satellites and ground stations sending out too many electromagnetic signals that can interfere with one another.The report comes at a time when the Federal Communications Commission is planning to reduce the spacing between satellites along the U.S. segment of the orbital arc so that 37 additional satellites can be squeezed into the high orbit favored for telecommunications. As more satellites are launched and others are shifted to avoid collisions, interference problems will get more complicated, say the authors of the report.

97

The role of the atmosphere in satellite geodesy, radio astronomy and other applications of trans-atmospheric propagation of radio waves  

Microsoft Academic Search

The influence of the atmosphere on radio waves relevant to technological applications is investigated theoretically, and the associated errors are classified and defined. Range errors are defined as the length of the phase path minus the geometric distance, and range errors are divided into those related to the troposphere and those related to the ionosphere. Ground-path error and group delay

R. Leitinger

1990-01-01

98

Low Earth orbit communications satellite  

NASA Astrophysics Data System (ADS)

A current thrust in satellite communication systems considers a low-Earth orbiting constellations of satellites for continuous global coverage. Conceptual design studies have been done at the time of this design project by LORAL Aerospace Corporation under the program name GLOBALSTAR and by Motorola under their IRIDIUM program. This design project concentrates on the spacecraft design of the GLOBALSTAR low-Earth orbiting communication system. Overview information on the program was gained through the Federal Communications Commission licensing request. The GLOBALSTAR system consists of 48 operational satellites positioned in a Walker Delta pattern providing global coverage and redundancy. The operational orbit is 1389 km (750 nmi) altitude with eight planes of six satellites each. The orbital planes are spaced 45 deg., and the spacecraft are separated by 60 deg. within the plane. A Delta 2 launch vehicle is used to carry six spacecraft for orbit establishment. Once in orbit, the spacecraft will utilize code-division multiple access (spread spectrum modulation) for digital relay, voice, and radio determination satellite services (RDSS) yielding position determination with accuracy up to 200 meters.

Moroney, D.; Lashbrook, D.; McKibben, B.; Gardener, N.; Rivers, T.; Nottingham, G.; Golden, B.; Barfield, B.; Bruening, J.; Wood, D.

99

Low Earth orbit communications satellite  

NASA Technical Reports Server (NTRS)

A current thrust in satellite communication systems considers a low-Earth orbiting constellations of satellites for continuous global coverage. Conceptual design studies have been done at the time of this design project by LORAL Aerospace Corporation under the program name GLOBALSTAR and by Motorola under their IRIDIUM program. This design project concentrates on the spacecraft design of the GLOBALSTAR low-Earth orbiting communication system. Overview information on the program was gained through the Federal Communications Commission licensing request. The GLOBALSTAR system consists of 48 operational satellites positioned in a Walker Delta pattern providing global coverage and redundancy. The operational orbit is 1389 km (750 nmi) altitude with eight planes of six satellites each. The orbital planes are spaced 45 deg., and the spacecraft are separated by 60 deg. within the plane. A Delta 2 launch vehicle is used to carry six spacecraft for orbit establishment. Once in orbit, the spacecraft will utilize code-division multiple access (spread spectrum modulation) for digital relay, voice, and radio determination satellite services (RDSS) yielding position determination with accuracy up to 200 meters.

Moroney, D.; Lashbrook, D.; Mckibben, B.; Gardener, N.; Rivers, T.; Nottingham, G.; Golden, B.; Barfield, B.; Bruening, J.; Wood, D.

1992-01-01

100

Satellite positioning  

NASA Technical Reports Server (NTRS)

Developments in satellite positioning techniques and their applications are reviewed on the basis of the theoretical and practical work published by U.S. researchers in 1987-1990. Current techniques are classified into two main categories: satellite laser tracking and radio tracking. Particular attention is given to the Geoscience Laser Ranging System, the Lunar Laser Ranging concept; GPS ephemerides determination, fiducial networks, and reference frame; static GPS positioning; and kinematic GPS positioning.

Colombo, Oscar L.; Watkins, Michael M.

1991-01-01

101

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.  

...complete contracting for construction of second space station or begin second space station construction; (3) Four years: In orbit operation of at least one space station; and (4) Six years: Full operation of the satellite system. (c)...

2014-10-01

102

Radio data transmission for SCADA  

SciTech Connect

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

Frasier, W.E. (Enron Corp., Houston, TX (US))

1989-09-01

103

Atmospheric sounding by global navigation satellite system radio occultation: An analysis of the negative refractivity bias using CHAMP observations  

Microsoft Academic Search

Validation studies of current GPS radio occultation experiments using meteorological analyses consistently report on a negative refractivity bias in the lower troposphere. End-to-end simulations including the GPS receiver's signal tracking process suggest that receiver-induced phase deviations contribute to this observed bias. We propose a heuristic retrieval algorithm based on the canonical transform and the sliding spectral technique, which seems less

G. Beyerle; J. Wickert; T. Schmidt; C. Reigber

2004-01-01

104

Domestic Communication Satellites  

ERIC Educational Resources Information Center

A discussion of the Federal Communications Commission's new policy on domestic satellites in light of our 1) military and economic history; 2) corporate interests; 3) citizen surveillance; and 4) media control. (HB)

Horowitz, Andrew

1974-01-01

105

Impairment of radio wave signal by rainfall on fixed satellite service on earth-space path at 37 stations in Nigeria  

NASA Astrophysics Data System (ADS)

This study investigates the effect of rainfall on horizontally polarized radio waves for fixed satellite service at Ku, Ka and V bands for links to the recently launched Nigeria Communication Satellite one (NigComSat-1), for annual time availabilities of 99-99.99% in an average year for 37 stations in Nigeria. The results obtained at Ku-band downlink shows that 99.99% availability is possible in all the 37-stations in Nigeria. At Ka-band downlink the results also show that only 99.9% availability is practicable in all the 37 stations in Nigeria. At V-band downlink, 99.99% availability is also not possible in all the 37 stations in Nigeria. An availability level of 99.9% is only practicable in the North-West (NW) and North-East (NE) regions, where the attenuation is between 14 and 17.9 dB. Total fade out of signals during rainfall are probable in the South-South (SS), South-East (SE), South-West (SW) and Middle-Belt (MB) regions at 99.9% availability.

Omotosho, T. V.; Oluwafemi, C. O.

2009-06-01

106

Packet radio tests, Lake Fryxell  

NSF Publications Database

Title : Packet radio tests, Lake Fryxell Type : Antarctic EAM NSF Org: OD / OPP Date : January 09 ... Memorandum (Satellite Packet Radio Tests at Lake Fryxell) To: Files S.7 (Environment) During the ...

107

The strategic corporate intelligence and transformational marketing model  

Microsoft Academic Search

Reference to the strategic marketing and corporate intelligence interface is made explicit in this paper, and various contributions to the field of competitive intelligence are highlighted. A conceptual model, known as the strategic corporate intelligence and transformational marketing (SATELLITE) model is outlined, and can be used by corporate intelligence staff to provide better marketing intelligence. The SATELLITE model provides a

Peter R. J. Trim

2004-01-01

108

Opportunities and Challenges of Nano Satellites  

E-print Network

for space development/utilization Technology development for nano-satellites and hybrid rockets http institute of technology #12;9 Feature of Nano-satellite Nano-satellite "Normal" satellite Mass 1 to 50Opportunities and Challenges of Nano Satellites August, 2010 Rei Kawashima AXELSPACE Corporation

109

Satellite orbit predictor  

NASA Technical Reports Server (NTRS)

An analog aid to determine satellite coverage of Emergency Locator Transmitters Emergency Position Indicating Radio Beacon (ELT/EPIRB) distress incidence is discussed. The satellite orbit predictor is a graphical aid for determining the relationship between the satellite orbit, antenna coverage of the spacecraft and coverage of the Local User Terminal. The predictor allows the user to quickly visualize if a selected position will probably be detected and is composed of a base map and a satellite track overlay for each satellite.A table of equator crossings for each satellite is included.

Friedman, Morton l.; Garrett, James, Major

110

Satellite atmospheres and magnetospheres.  

NASA Astrophysics Data System (ADS)

Galileo radio-occultation measurements show that all four of the Galilean satellites possess ionospheres. Peak ionospheric densities for the icy satellites are several thousand electrons per cubic centimeter, and the distributions are not spherically symetric. Io's ionosphere is much denser and remarkably simiilar to that measured by Voyager.

Kliore, A. J.

111

Radio science investigations with Voyager  

NASA Technical Reports Server (NTRS)

Radio links to and from the Voyager spacecraft will be used for occultation measurements of planetary and satellite atmospheres and ionospheres, the rings of Saturn, the solar corona, and the general-relativistic time delay for radio wave propagation through the solar gravity field. In addition, the radio link measurements may provide information on the gravity fields of the planets, the masses of the satellites, properties of the interplanetary medium, and long-wavelength gravitational radiation propagation in the solar system.

Eshleman, V. R.; Tyler, G. L.; Anderson, J. D.; Fjeldbo, G.; Levy, G. S.; Wood, G. E.; Croft, T. A.

1977-01-01

112

Magnetospherically reflected, specularly reflected, and backscattered whistler mode radio-sounder echoes observed on the IMAGE satellite: 1. Observations and interpretation  

NASA Astrophysics Data System (ADS)

A survey of echoes detected in 2004-2005 during pulse transmissions from the Radio Plasma Imager (RPI) instrument on the IMAGE satellite has revealed several new features of sounder generated whistler mode (WM) echoes and has indicated ways in which the echoes may be used for remote sensing of the Earth's plasma structure at altitudes <5000 km. In this paper we describe the frequency versus travel time (f - t) forms of the WM echoes as they appear on RPI plasmagrams and discuss qualitatively their raypaths and diagnostic potentials. Based on their reflection mechanism, the WM echoes can be classified as: magnetospherically reflected (MR), specularly reflected (SR), or backscattered (BS). The MR echoes are reflected at altitudes where the local lower hybrid frequency (flh) is equal to the transmitted pulse frequency f, a phenomenon familiar from both theory and passive recordings of WM wave activity. The SR echoes (previously reported in a higher frequency range) are reflected at the Earth-ionosphere boundary, either with wave vector at normal incidence or, more commonly (and unexpectedly, due to ray bending in the layered ionosphere), at oblique incidence. The BS echoes are the result of scattering from small scale size plasma density irregularities close to IMAGE. The echoes are described as discrete, multipath, and diffuse, depending upon the amount of travel-time spreading caused by the presence of field aligned density irregularities (FAIs) along echo raypaths. The WM echoes described in this paper have been observed at altitudes less than 5,000 km and at all latitudes and at most MLTs. The diagnostic potential of these phenomena for remotely studying the distribution of plasma density and composition along the geomagnetic field line B0, as well as the presence of FAIs of varying scale sizes, is enhanced by the tendency for SR and MR echoes to be observed simultaneously along with the upward propagating signals from a spatial distribution of communication VLF transmitters. We believe that our findings about WM propagation and echoing in an irregular medium have important implications for the connection between WM waves and the Earth's radiation belts. In a companion paper by Sonwalkar et al. (2011), we employ ray tracing and refractive index diagrams in quantitative support of this paper and also present two diagnostic case studies of plasma density, ion effective mass, and ion composition along B0.

Sonwalkar, V. S.; Carpenter, D. L.; Reddy, A.; Proddaturi, R.; Hazra, S.; Mayank, K.; Reinisch, B. W.

2011-11-01

113

Radio Astronomy Radio astronomy  

E-print Network

Effelsberg 100m telescope (Germany) Green Bank 100m telescope (National Radio Astronomy ObservatoryExperiment -10m (Chile, Europe) #12;Submillimeter radio astronomy #12;Size of telescope Snow sweep at Nobeyama 45;#12;Arecibo 300m telescope #12;Radio interferometer #12;Radio interferometer Very Large Array (VLA) (New

Metchev, Stanimir

114

Civil satellite navigation and location systems  

NASA Astrophysics Data System (ADS)

The use of satellites for civil navigation and location, including satellites not necessarily launched for that purpose, is reviewed. In particular, attention is given to differences between civil and military satellites; civil use of military systems and the associated commercial considerations and regulatory issues; the use of communication satellites; and radiodetermination satellite service based on geostationary satellites. The discussion also covers integration with ground-based radio-navigation systems; existing radio-navigation satellite systems; and the Starfix, Geostar/Locstar, Starfind, Navsat, and Rexstar systems.

Blanchard, W. F.

1989-05-01

115

'RARC '83' - International planning for broadcasting satellites at 12 GHz  

NASA Astrophysics Data System (ADS)

It is pointed out that 14 corporations have applied to the Federal Communications Commission (FCC) to operate broadcasting satellite systems in the U.S. The applications are concerned with operations in the 12 GHz band. In connection with these applications, the FCC is placed into a difficult position, related partly to uncertainties regarding the portion of the limited orbit spectrum resource which will be available to the U.S. In June of 1983, the Regional Administrative Radio Conference (RARC '83) will be convened for the planning of broadcasting satellites for Region 2, which consists basically of the Americas and the Caribbean. One type of planning favored by many countries would involve very detailed specification or orbit spectrum 'allotments' to the various administrations. The consequences of such an approach are critically evaluated. Attention is given to the geostationary orbit-spectrum, U.S. preparatory efforts, and a scenario to minimize a-priori planning.

Hupe, H. H.

116

(Astro)Physics 343 Observational Radio Astronomy  

E-print Network

. Last year: "Current and Future Radio Astronomy Projects" This year: the search for extraterrestrial intelligence? the New Jersey roots of radio astronomy? why the Iridium telecommunications satellites are evil

Baker, Andrew J.

117

Radio Galaxies.  

ERIC Educational Resources Information Center

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

Downes, Ann

1986-01-01

118

Wall Street Journal via satellite  

Microsoft Academic Search

The paper describes the inaugural satellite newspaper facsimile transmission system implemented by American Satellite Corporation for Dow Jones and Company. The system is intended to provide remote printing of the Wall Street Journal from the Dow Jones Chicopee, Massachusetts plant to its newly built Orlando, Florida facility.

E. R. Cacciamani; G. C. Jenkins

1976-01-01

119

26 CFR 1.955-5 - Definition of less developed country corporation.  

... Foreign corporation A is formed on November 1, 1963, to engage in the business of manufacturing and selling radios in Brazil, a less developed country as of November 1, 1963. Corporation A uses the calendar year as a taxable year....

2014-04-01

120

26 CFR 1.955-5 - Definition of less developed country corporation.  

Code of Federal Regulations, 2013 CFR

... Foreign corporation A is formed on November 1, 1963, to engage in the business of manufacturing and selling radios in Brazil, a less developed country as of November 1, 1963. Corporation A uses the calendar year as a taxable year....

2013-04-01

121

26 CFR 1.955-5 - Definition of less developed country corporation.  

Code of Federal Regulations, 2011 CFR

... Foreign corporation A is formed on November 1, 1963, to engage in the business of manufacturing and selling radios in Brazil, a less developed country as of November 1, 1963. Corporation A uses the calendar year as a taxable year....

2011-04-01

122

26 CFR 1.955-5 - Definition of less developed country corporation.  

Code of Federal Regulations, 2012 CFR

... Foreign corporation A is formed on November 1, 1963, to engage in the business of manufacturing and selling radios in Brazil, a less developed country as of November 1, 1963. Corporation A uses the calendar year as a taxable year....

2012-04-01

123

26 CFR 1.955-5 - Definition of less developed country corporation.  

Code of Federal Regulations, 2010 CFR

... Foreign corporation A is formed on November 1, 1963, to engage in the business of manufacturing and selling radios in Brazil, a less developed country as of November 1, 1963. Corporation A uses the calendar year as a taxable year....

2010-04-01

124

NASA and CD Radio's TDRSS industrial test program  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) has embarked on a joint test program with CD Radio Inc. The program will demonstrate spatial diversity techniques in support of industrial development of a new satellite direct broadcast national radio service called Satellite Radio. Satellite Radio will operate in the FCC approved frequency band 2310-2360 MHz which is close to NASA's Tracking and Data Relay System (TDRSS) satellites' high power transmit frequency near 2110 MHz. The cooperative test program in which NASA provides use of a TDRSS satellite and CD Radio provides the measurement equipped vehicle is described as well as its current status. Some initial measurement data are presented.

Briskman, Robert D.; Hollansworth, James E.

1995-01-01

125

Improvements in search and rescue distress alerting and locating using satellites  

NASA Technical Reports Server (NTRS)

This paper describes a system concept for search and rescue which is capable of making a major contribution to saving lives and reducing the search time for downed aircraft. In addition, a beacon location experiment is described using the Amateur Radio Satellite Corporation Oscar-6 and Oscar-7 spacecraft. The purpose of this experiment was to demonstrate the system concept above by determining the geographical location of a low power 'distress beacon' via satellite based on a single pass of Doppler frequency measurements. Preliminary results are presented showing beacon location recovery on the order of 10 km with indications that an order of magnitude improvement is entirely possible. This experiment is in support of NASA's current exploration into the role satellites might play in providing much needed improvements in the reliability, coverage and accuracy of present search and rescue procedures.

Brandel, D. L.; Schmid, P. E.; Trudell, B. J.

1976-01-01

126

Impact of the direct sequence spread spectrum signals from the global satellite navigation system GLONASS on radio astronomy: problem and proposed solution  

Microsoft Academic Search

The GLONASS satellites use direct sequence spread spectrum with a P-code chip rate of 5.11 MHz. On their L1 channels near 1600 MHz they also carry a 0.511 MHz chip rate C\\/A-code. The satellites are distinguished by FDMA having carrier frequencies spaced 0.5625 MHz apart. The digital code sequences are used directly to switch the phase of the carriers. This

J. E. B. Ponsonby

1994-01-01

127

Corporal punishment.  

PubMed

Corporal punishment is used for discipline in most homes in the United States. It is also associated with a long list of adverse developmental, behavioral, and health-related consequences. Primary care providers, as trusted sources for parenting information, have an opportunity to engage parents in discussions about discipline as early as infancy. These discussions should focus on building parents' skills in the use of other behavioral techniques, limiting (or eliminating) the use of corporal punishment and identifying additional resources as needed. PMID:25242709

Zolotor, Adam J

2014-10-01

128

Boundary Layer Remote Sensing with Combined Active and Passive Techniques: GPS Radio Occultation and High-Resolution Stereo Imaging (WindCam) Small Satellite Concept  

NASA Technical Reports Server (NTRS)

Objective: significant progress in understanding low-cloud boundary layer processes. This is the Single largest uncertainty in climate projections. Radio occultation has unique features suited to boundary layer remote sensing (1) Cloud penetrating (2) Very high vertical resolution (approximately 50m-100m) (3) Sensitivity to thermodynamic variables

Mannucci, A.J.; Wu, D.L.; Teixeira, J.; Ao, C.O.; Xie, F.; Diner, D.J.; Wood, R.; Turk, Joe

2012-01-01

129

Cantro Corporation  

Microsoft Academic Search

John Williams, marketing manager of the industrial valve division of Cantro Corporation, must decide on pricing policies for his division's two products, lubricated and eccentric plug valves. These two products exhibit different cost structures and competitive characteristics. The division's objectives for these products are: (1) to maintain and increase market share, (2) to improve profits, and (3) to maintain a

Derek Newton; E. Brownlee

130

Satellite (IRLS) tracking of elk  

NASA Technical Reports Server (NTRS)

The practicability of tracking free roaming animals in natural environments by satellite systems is reported. Satellite systems combine continuous tracking with simultaneous monitoring of physiological and environmental parameters through a combination of radio tracking and biotelemetric ground systems that lead to a better understanding of animal behavior and migration patterns.

Buechner, H. K.

1972-01-01

131

Mobile satellite service communications tests using a NASA satellite  

NASA Technical Reports Server (NTRS)

Emerging applications of commercial mobile satellite communications include satellite delivery of compact disc (CD) quality radio to car drivers who can select their favorite programming as they drive any distance; transmission of current air traffic data to aircraft; and handheld communication of data and images from any remote corner of the world. Experiments with the enabling technologies and tests and demonstrations of these concepts are being conducted before the first satellite is launched by utilizing an existing NASA spacecraft.

Chambers, Katherine H.; Koschmeder, Louis A.; Hollansworth, James E.; ONeill, Jack; Jones, Robert E.; Gibbons, Richard C.

1995-01-01

132

Astronomy research at the Aerospace Corporation. [research projects - NASA programs  

NASA Technical Reports Server (NTRS)

This report reviews the astronomy research carried out at The Aerospace Corporation during 1974. The report describes the activities of the San Fernando Observatory, the research in millimeter wave radio astronomy as well as the space astronomy research.

Paulikas, G. A.

1974-01-01

133

The ionosphere as a focusing lens - A case study involving simultaneous type III solar radio storm measurements from the ISIS 1 and 2 and ISEE 3 satellites  

NASA Technical Reports Server (NTRS)

The possibility of using terrestrial ionospheric focusing to improve the directivity of electric dipoles on space missions has been investigated by comparing simultaneous observations of a solar radio storm by the ISIS 1 and ISIS 2 spacecraft, in near earth orbit, and the ISEE 3 spacecraft located beyond the magnetosphere. To this end, a three-dimensional ray tracing in a spherically stratified ionosphere has been carried out for conditions appropriate to the observations by the ISIS spacecraft of a solar radio storm in September 1983. The procedure allows Poynting flux spectral densities measured on ISIS to be converted to spectral densities well outside the ionosphere where they can be compared directly with simultaneous observations on ISEE 3. The results demonstrate good agreement over their common observing frequency range (1-2 MHz).

James, H. G.; Benson, R. F.; Fainberg, J.; Stone, R. G.

1990-01-01

134

Simulation of the Mars Ionosphere Radio Occultation Experiments  

Microsoft Academic Search

The Mars ionosphere radio occultation experiment between the Chinese YH-1 spacecraft and the Russian Phobos-Grunt spacecraft orbiting Mars will be the first satellite to satellite radio occultation experiment in history, which will achieve high quality ionospheric electron density profiles. The technique used in this experiment is analyzed and introduced. Simulations of the radio occultation have been completed. Forward calculations of

X. Hu; X. C. Wu; X. Y. Gong; X. Wang; Q. C. Xu

2009-01-01

135

Corporate CardsCorporate Cards Travel Card  

E-print Network

Corporate CardsCorporate Cards Travel Card Fleet CardFleet Card Purchasing Card #12;All Corporate CardsAll Corporate Cards Current contract is with BMO MasterCardCurrent contract is with BMO MasterCard Credit rating is based on the University's credit and not your personal credit.you pe so a c ed t Cards

Brownstone, Rob

136

Compact private hubs for corporate VSAT networks  

NASA Astrophysics Data System (ADS)

Satellite communications has played a significant role in making information networks a strategic corporate asset. Very small aperture terminal (VSAT) networks, in particular, have special appeal for the corporate network user community because of unique advantages in cost, operations, and user control. The recent rapid proliferation of these networks in a multitude of market segments, as diverse as retail and financial services, is evidence of their wide acceptance for business communications.

Shimabukuro, Tom M.; Subbarayan, Ravi

137

Geron Corporation  

NSDL National Science Digital Library

Geron Corporation is a biopharmaceutical company specializing in therapeutic and diagnostic products for age-related diseases. Geron owns several telomerase related patents. Calvin B. Harley of Geron is one of the co-authors of the Science article. Their page describes programs and products related to cellular aging and Cancer Therapeutics. There has been a recent finding regarding telomerase, a gene which affects the mechanisms controlling human cell replication. The site above provides general information on telomerase, current telomere research, and the use of telemorase in medical practice. Telomerase increases the life-span of a cell, and is thus central to both aging and cancer.

1998-01-01

138

Satellite Communication.  

ERIC Educational Resources Information Center

Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies

Technology Teacher, 1985

1985-01-01

139

Geodynamics from satellites  

NASA Technical Reports Server (NTRS)

The NASA Geodynamics Program is developing a variety of techniques in support of national programs in geodynamics, geomagnetics and earthquake hazard reduction. Global tectonics are to be observed by satellite laser tracking and radio interferometry, which will be used to measure the movements of extended (greater than 200 km) regions to an accuracy of 3 cm, while for shorter distances, lasers enable a more rapid measuring of regional strain accumulation patterns than ground systems. The techniques of Doppler tracking between two satellites to measure the gravity field over the ocean is also under NASA study

Kaula, W. M.

1979-01-01

140

Mobile satellite regulation in the United States  

NASA Technical Reports Server (NTRS)

During the last decade, the U.S. FCC has developed the regulatory structure for the provision of mobile services via satellite. In May 1989, the FCC awarded American Mobile Satellite Corporation (AMSC) a license to provide the full range of domestic mobile satellite services in the U.S. At that time, the FCC reaffirmed the U.S. mobile satellite industry structure and spectrum allocations that had been adopted previously. Also in May 1989, the FCC authorized the Communications Satellite Corporation (COMSAT), the U.S. Signatory to Inmarsat, to provide international aeronautical satellite service via the Inmarsat system. Earlier in 1989, the FCC permitted the use of Ku-band satellites to provide messaging and tracking services. In the mid-1980's, the FCC established the Radiodetermination Satellite Service and awarded licenses. Among the mobile satellite matters currently facing the FCC are whether additional spectrum should be allocated for domestic 'generic' mobile satellite services, the regulatory structure for the provision of mobile satellite service on an interim basis before AMSC launches its dedicated satellites, and whether to authorize a low earth orbit satellite system to provide mobile data service.

Levin, Lon C.; Sonnenfeldt, Walter H.

1990-01-01

141

Theories of Corporate Groups: Corporate Identity Reconceived  

E-print Network

Theoretical debates about the nature of the corporation have raged for over a century, with competing visions of the corporation holding sway in different regulatory arenas and each making claims for normative supremacy. ...

Harper Ho, Virginia E.

2012-06-17

142

Investigation of a rift zone in the western Fimbulisen by means of airborne radio echo sounding, satellite imagery, and ice flow modelling  

NASA Astrophysics Data System (ADS)

The Fimbulisen, an ice shelf located roughly between 3W-8E at the coast of Dronning Maud Land, East Antarctica, consists of the fast flowing extension of Jutulstraumen and slower moving parts west and east of it. The largely rifted western part of the Fimbulisen is the subject of this study, which combines observations and modelling. Airborne radio echo sounding performed by the Alfred Wegener Institute between 1996 and 2008 with a frequency of 150 MHz and pulse length of 60 ns, respectively 600 ns, is analysed in order to study the internal structure of the ice in parts of the rift zone and to estimate the ice thickness in this area precisely. High-resolution radar imagery acquired by the TerraSAR-X in 2008 and 2009 is used to evaluate principal deformation axis at characteristic locations, to detect crack modes as well as to classify zones of similar structural characteristics. These zones were incorporated in a 2D diagnostic ice flow model as sub-domains with variable stress enhancement factor and thus treated as zones of different damage related stiffness. The temperature-dependent stiffness is calculated by applying the solution of a validated 3D temperature model of the ice shelf and thus the simulations focus on the softening effect caused by cracks. Extensive parameter studies show the effect of the stress enhancement factor on the principal deformation rates and axis. Comparison with the estimated deformation pattern aims to confine the softening effect for each zone separately.

Humbert, Angelika; Steinhage, Daniel

2010-05-01

143

Solar Power Satellite (SPS) pilot beam and communication link subsystem investigation study, phase 1. [ionospheric propagation, radio frequency interference, and microwave transmission  

NASA Technical Reports Server (NTRS)

A preliminary engineering model of ionospheric interactions with the pilot beam was established and used to demonstrate that the dual frequency baseline pilot beam system might not be viable in the presence of an unstable transmission path. Alternate approaches to remove this difficulty are described. Although ionospheric fluctuations will not significantly degrade beam pointing or raise the sidelobe levels, they will reduce transmission efficiency by upwards of 25%. Mitigating strategies to substantially reduce this effect are proposed. Based on the Klystron noise spectrum, the pilot beam transmitter power was determined as a function of frequency offset from the power beam carrier frequency. The RFI from the pilot beam, on the ground and at geosynchronous orbit is shown. Noise levels on the earth's surface due to the SPS are presented as a function of frequency and the number of SPS systems. Analysis of the communication subsystem indicates that a standard telemetry line of 1.544 MB/s would satisfy both voice and data link requirements. Additional links would be required for TV and radio transmissions.

1979-01-01

144

Hitchhiker payloads for new commercial satellite services  

NASA Astrophysics Data System (ADS)

A hitchhiker package is an addition to a satellite which provides a payload capability not previously present on the satellite and which utilizes a relatively minor portion of the available satellite resources. In this paper, feasibility considerations for hitchhiker packages are discussed in a general way, and some practical hitchhiker packages are described. These are the Search and Rescue Satellite Aided Tracking System (SARSAT), the Geostar Radio Determination (RDSS) hitchhiker packages, the Aviation Satellite (Avsat) proposed early entry system, and the Mobile Satellite (MSS) proposed early entry system.

Elizondo, E. L.; Buntschuh, R. F.; Seliga, J. F.

145

Radio telescopes  

Microsoft Academic Search

A radio telescope is used in radio astronomy to measure the intensity of the radiation received from various parts of the sky. Such a telescope must be able both to detect and to locate faint radio sources of small angular size, and also to measure the brightness distribution across extended radio sources or over large sky areas. Ideally the telescope

J. Findlay

1964-01-01

146

The advisability of competitive international satellites  

NASA Astrophysics Data System (ADS)

This analysis examines the legal, political, and economic issues raised by the applications of Orion Satellites Corporation and International Satellite, Inc., before the Federal Communications Commission. The proposals request approval for the establishment of communications satellite systems potentially competitive with the International Telecommunications Satellite Organization (INTELSAT), a consortium of 109 member nations, which currently maintains a monopoly of international communications satellite traffic. The breadth of consequences resulting from a positive FCC action warrants a close scrutiny of U.S. international foreign policy objectives.

Greenhalgh, D. I.

147

IR Spectrophotometric Observations of Geosynchronous Satellites  

NASA Astrophysics Data System (ADS)

We have observed several geosynchronous satellites at the Advanced Electro-Optical System (AEOS) 3.6 meter telescope, utilizing The Aerospace Corporation's Broadband Array Spectrograph System (BASS) 3-13 micron sensor, as well as the site's Hi-VIS 1-2.5 micron spectrograph. The various satellites show different trends with phase angle, which may allow satellite identification based on observables. Data were collected on several nights, on multiple satellites, and at various phase angles for each satellite. We describe our methods, our data, our analysis, and our results.

Skinner, M.; Payne, T.; Russell, R.; Gutierrez, D.; Crawford, K.; Harrington, D.; Kim, D.; Lynch, D.; Rudy, R.

148

Description of the AMSC mobile satellite system  

NASA Astrophysics Data System (ADS)

The American Mobile Satellite Corporation will provide a full range of mobile satellite services through a mobile satellite system dedicated to mobile use in the United States. This paper provides a summary of the system architecture with descriptions of each of the major system elements. The elements are the space segment, network control system, mobile earth terminals and feeder-link earth stations. The general transmission plan is also described.

Garner, W. B.

149

How Far Away Are the Satellites?  

NSDL National Science Digital Library

In this activity, students calculate the distance from a satellite to a receiving station on Earth. They will learn that radio signals are waves and that wave characteristics can be used to measure properties such as velocity, distance, and time.

Glasscoe, Maggi

2010-06-10

150

How Far Away Are the Satellites?  

NSDL National Science Digital Library

In this activity, students calculate the distance from a satellite to a receiving station on Earth. They will learn that radio signals are waves and that wave characteristics can be used to measure properties such as velocity, distance, and time.

Glasscoe, Maggi

151

Galileo radio science investigations  

NASA Technical Reports Server (NTRS)

Galileo radio-propagation experiments are based on measurements of absolute and differential propagation time delay, differential phase delay, Doppler shift, signal strength, and polarization. These measurements can be used to study: the atmospheric and ionospheric structure, constituents, and dynamics of Jupiter; the magnetic field of Jupiter; the diameter of Io, its ionospheric structure, and the distribution of plasma in the Io torus; the diameters of the other Galilean satellites, certain properties of their surfaces, and possibly their atmospheres and ionospheres; and the plasma dynamics and magnetic field of the solar corona. The spacecraft system provides linear rather than circular polarization on the S-band downlink signal, the capability to receive X-band uplink signals, and a differential downlink ranging mode. A highly-stable, dual-frequency, spacecraft radio system is developed that is suitable for simultaneous measurements of all the parameters normally attributed to radio waves.

Howard, H. T.; Eshleman, V. R.; Hinson, D. P.; Kliore, A. J.; Lindal, G. F.; Woo, R.; Bird, M. K.; Volland, H.; Edenhoffer, P.; Paetzold, M.

1992-01-01

152

Satellite reconnaissance  

NASA Astrophysics Data System (ADS)

The potential of the observation equipment in remote sensing satellites is described. United States meteorology, land use and oceanography satellites and the major US Earth observation programs are listed. Imaging satellite systems are described such as: visible light and near infrared, thermal IR window, and microwave window. It is concluded that a geometrical resolution between 10 and 40 m can be expected. In order to reduce the data flow from the satellite system the input side of the system (the object-sensor interaction) has to be known. Satellites with synthetic aperture radar are increasingly important, but satellites can never fully replace observations with aircraft and drones.

Deloor, G. P.

1984-06-01

153

Use of communications. [satellite communication  

NASA Technical Reports Server (NTRS)

Progress in the field of satellite communications is reviewed, and useful services which may be provided by future satellite communications systems are considered. Recommendations are made with regard to mobile communications for use on land and at sea, position determination, mineral and energy exploration, the possibility of using electronic means to assist in main delivery, education and health-care experiments, and the use of satellite telecommunications to enhance the quality of life in rural areas by making available a full range of educational and entertainment programs. The needs of the amateur radio community are also considered.

1975-01-01

154

The Direct Satellite Connection: Definitions and Prospects.  

ERIC Educational Resources Information Center

Defines direct satellite broadcasting as the transmission of broadcast signals via high-powered satellites that permit direct reception of television or radio programs by means of small antennas. Outlines American, European, and Japanese plans for direct-to-home television reception and implications for the broadcasting industry. (JMF)

Wigand, Rolf T.

1980-01-01

155

Satellite navigation method based on user's clock synchronization  

NASA Astrophysics Data System (ADS)

This paper presents a satellite navigation method which is based on the synchronization of a user clock, using bidirectional satellite communication. This method is effectively applied to cope with the reduction of range-finding data due to satellite failure or limited field of view, and is also applicable to a Radio Determination Satellite System such as Geostar, which uses two geostationary satellites as means of relaying range-finding signals, and supplies communication service at the same time. Analytical results are discussed.

Yamawaki, Koji

156

Leisure, civil disobedience, and the history of low power FM (LPFM) radio  

Microsoft Academic Search

This paper traces the historical development of two trends in radio policy and practice, megapower (corporate) and micropower (also termed pirate or low power FM) broadcasting. In reaction to a flurry of deregulation and corporate consolidation, a micropower movement has recently emerged. My aim is to illustrate some of the political, social, and historical processes that have shaped radio as

Brett D. Lashua

2005-01-01

157

Radio Astronomy  

NSDL National Science Digital Library

This article is a Why Files short piece on how astronomers use information from radio astronomy. Contrary to popular belief, large radio telescopes are not looking for signs of life outside our solar system, but are making images of black holes, centers of galaxies, and gamma ray bursts. These phenomena cannot be seen in visible light, but emit radio waves which can be translated into images. The article discusses how this process works, and the information gathered from radio waves.

Tenenbaum, David

158

Regulation of Wire and Radio Communication.  

ERIC Educational Resources Information Center

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

Federal Communications Commission, Washington, DC.

159

Planetary radio astronomy experiment for Voyager missions  

Microsoft Academic Search

The planetary radio astronomy experiment will measure radio spectra of planetary emissions in the range 1.2 kHz to 40.5 MHz. These emissions result from wave-particle-plasma interactions in the magnetospheres and ionospheres of the planets. At Jupiter, they are strongly modulated by the Galilean satellite Io.

J. W. Warwick; J. B. Pearce; R. G. Peltzer; A. C. Riddle

1977-01-01

160

LDEF Satellite Radiation Analyses  

NASA Technical Reports Server (NTRS)

This report covers work performed by Science Applications International Corporation (SAIC) under contract NAS8-39386 from the NASA Marshall Space Flight Center entitled LDEF Satellite Radiation Analyses. The basic objective of the study was to evaluate the accuracy of present models and computational methods for defining the ionizing radiation environment for spacecraft in Low Earth Orbit (LEO) by making comparisons with radiation measurements made on the Long Duration Exposure Facility (LDEF) satellite, which was recovered after almost six years in space. The emphasis of the work here is on predictions and comparisons with LDEF measurements of induced radioactivity and Linear Energy Transfer (LET) measurements. These model/data comparisons have been used to evaluate the accuracy of current models for predicting the flux and directionality of trapped protons for LEO missions.

Armstrong, T. W.; Colborn, B. L.

1996-01-01

161

Cognitive radio: Making software radios more personal  

Microsoft Academic Search

Software radios are emerging as platforms for multiband multimode personal communications systems. Radio etiquette is the set of RF bands, air interfaces, protocols, and spatial and temporal patterns that moderate the use of the radio spectrum. Cognitive radio extends the software radio with radio-domain model-based reasoning about such etiquettes. Cognitive radio enhances the flexibility of personal services through a Radio

Joseph Mitola; Gerald Quentin Maguire Jr.

1999-01-01

162

A study of satellite emergency locator systems  

NASA Technical Reports Server (NTRS)

Satellite emergency locator systems were studied. The objective of the study was to determine the feasibility and hardware requirements for satellite systems capable of identifying and locating the position emergency locator transmitters and emergency position indicating radio beacons. Both geosynchronous and near-polar-orbiting satellites were considered. One of the most important aspects of the study was to minimize the cost of the hardware required.

1977-01-01

163

Engineering calculations for communications satellite systems planning  

NASA Astrophysics Data System (ADS)

The final phase of a satellite synthesis project is described. Several methods for generating satellite positionings with improved aggregate carrier to interference characteristics were studied. Two general methods for modifying required separation values are presented. Also, two methods for improving aggregate carrier to interference (C/I) performance of given satellite synthesis solutions are presented. A perturbation of the World Administrative Radio Conference (WARC) synthesis is presented.

Walton, E.; Aebker, E.; Mata, F.; Reilly, C.

1991-05-01

164

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

The final phase of a satellite synthesis project is described. Several methods for generating satellite positionings with improved aggregate carrier to interference characteristics were studied. Two general methods for modifying required separation values are presented. Also, two methods for improving aggregate carrier to interference (C/I) performance of given satellite synthesis solutions are presented. A perturbation of the World Administrative Radio Conference (WARC) synthesis is presented.

Walton, E.; Aebker, E.; Mata, F.; Reilly, C.

1991-01-01

165

Canadian Broadcasting Corporation Archives: Science and Technology  

NSDL National Science Digital Library

This collection of radio and television clips from the archives of the Canadian Broadcasting Corporation (CBC) lets users explore the scientific and medical inventions, discoveries, and developments that have shaped Canada's history. The clips are organized by topic, including climate change, medical research, natural disasters, technology, pollution, and many others. There is also a collection of "On this Day" clips celebrating the anniversaries of important scientific and technological events in Canada.

166

Corporate sustainability assessment methodology  

E-print Network

Sustainability is a vague concept specifically in the context of a corporate world. There are numerous definitions for corporate sustainability and just as many ways of evaluating it. This work attempts to define, structure ...

Pinchuk, Natallia

2011-01-01

167

ENGAGING UNH Corporate Resources  

E-print Network

.or.Underwriting.with.NHPTV Corporate.Meetings.and.Hotel.Arrangements Experts.Sciences.and.Engineering Materials.Sciences Social.and.Health.Sciences Sustainability.Programs TABLE OF CONTENTS #12;Corporate

New Hampshire, University of

168

Essays on corporate bonds  

E-print Network

This thesis consists of three empirical essays on corporate bonds, examining the role of both credit risk and liquidity. In the first chapter, I test the ability of structural models of default to price corporate bonds in ...

Bao, Jack (Jack C.)

2009-01-01

169

Irregularities in ionospheric plasma clouds: Their evolution and effect on radio communication  

Microsoft Academic Search

Both satellite radio communications, which travel through the Earth's ionosphere, and high frequency (HF) sky wave circuits, which use the ionosphere as a refracting medium, can be strongly affected by radio wave scintillation. High altitude nuclear explosions cause scintillation (by strongly disturbing the ionosphere) and thus severely degrade satellite radio communications over a large region. Since further atmospheric nuclear tests

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

1980-01-01

170

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

Microsoft Academic Search

Both satellite radio communications, which travel through the Earth's ionosphere, and high frequency (HF) sky wave circuits, which use the ionosphere as a refracting medium, can be strongly affected by radio wave scintillation. High altitude nuclear explosions cause scintillation (by strongly disturbing the ionosphere) and thus severely degrade satellite radio communications over a large region. Since further atmospheric nuclear tests

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

1980-01-01

171

Firefighters' Radios  

NASA Technical Reports Server (NTRS)

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

1976-01-01

172

Corporations and Library Fundraising.  

ERIC Educational Resources Information Center

Examination of corporate donations of cash, products, service, and expertise to libraries highlights industry contributions in 1980; why corporations give; examples of corporate donations to various libraries (Brooklyn Public, New York Public, Altoona Area Public, Boston Public); planning fund-raising compaigns; and seven strategic planning

DiMattia, Susan S.

1984-01-01

173

Corporate governance & IT  

Microsoft Academic Search

Known for its international approach to corporate governance and its accessible nature, Corporate Governance has established itself as an invaluable text for both undergraduate and postgraduate students. Chris Mallin introduces the reader to the theories and development of corporate governance, before looking at owners and stakeholders and directors, all the time illustrating the theory with examples from the press and

Michael S. Weisbach; Francis E. Warnock; Rohan Williamson

1996-01-01

174

Measurement of Terrestrial Radio Noise  

Microsoft Academic Search

The terrestrial noise experiment on the Ariel III satellite is designed to measure the radio noise from lighting discharges, and to deduce the distribution of the sources. The measurements are made at high frequencies; at optimum frequencies the noise penetrates the ionosphere only at near vertical incidence and the sources can therefore be localized. The receivers operate in narrow bandwidths

F. Horner; R. B. Bent

1969-01-01

175

Satellite orbit determination  

NASA Technical Reports Server (NTRS)

A historic account of the activities of the Satellite OD Group during the MM'71 mission is given along with an assessment of the accuracy of the determined orbit of the Mariner 9 spacecraft. Preflight study results are reviewed, and the major error sources described. Tracking and data fitting strategy actually used in the real time operations is itemized, and Deep Space Network data available for orbit fitting during the mission and the auxiliary information used by the navigation team are described. A detailed orbit fitting history of the first four revolutions of the satellite orbit of Mariner 9 is presented, with emphasis on the convergence problems and the delivered solution for the first orbit trim maneuver. Also included are a solution accuracy summary, the history of the spacecraft orbit osculating elements, the results of verifying the radio solutions with TV imaging data, and a summary of the normal points generated for the relativity experiment.

Jordan, J. F.; Boggs, D. H.; Born, G. H.; Christensen, E. J.; Ferrari, A. J.; Green, D. W.; Hylkema, R. K.; Mohan, S. N.; Reinbold, S. J.; Sievers, G. L.

1973-01-01

176

Engineers checkout Early Bird-Communication Satellite  

NASA Technical Reports Server (NTRS)

Engineers Stanley R. Peterson (left) and Ray Bowerman (right), checkout the Early Bird, the world's first communication satellite. NASA launched the satellite built by Hughes Aircraft Corporation on April 6, 1955 at 6:48pm E.S.T. from Complex 17a at Cape Kennedy, Florida. Early Bird was built for the Communications Satellite Corporation and weighed about 85 pounds after being placed in a synchronous orbit of 22,300 miles above the earth. It was positioned over the Atlantic to provide 240 two-way telephone channels or 2-way television between Europe and North America. The outer surface of Early Bird was covered with 6,000 silicon-coated solar cells, which absorbed the sun's rays to provide power to the satellite for its intricate transmitting and receiving equipment.

1984-01-01

177

Artificial Satellites  

NSDL National Science Digital Library

Over 2,000 man-made satellites are currently orbiting the Earth, providing a wide range of services like communications, remote sensing, and global positioning. As more are launched and new technologies are developed, they will play an increasingly important role in everyday life.The Tech Museum offers this site (1) dedicated to the basics of satellites and their functions. A Java program complements the Satellite Anatomy section, which illustrates the standard components of three different categories of satellites. More information specific to satellite launches and their orbits can be found here (2). Most of the material is composed of fun experiments that demonstrate satellite operation. One of the most interesting features on this NASA site (3) is the Live 3D Java Tracking Display, which shows hundreds of different satellites and their current position in orbit. A few selected news articles and a separate section on satellite applications are also provided. The European Space Agency provides a look at solar power satellites (4), which could essentially "beam" energy to Earth. While it is not a new concept, the sheer magnitude of a project to construct a solar power satellite has thus far been too great to justify an attempt. At a conference held in December 2002 (5), representatives from the satellite industry convened to discuss current developments. Although many of the articles only address industry outlooks, some are more technology-oriented. For instance, one considers a new navigation system that could improve overall coverage and signal availability. A lesson plan (6) for grades K-5 teaches children how satellites are launched and some basic terminology. The activity uses different sized marbles, clay, and some other items to demonstrate fundamental concepts. Satellites of the Global Positioning System are being used for more than they were originally intended in England. This news article (7) describes how they are used to study earthquakes and corresponding movements in the Earth's crust. In other news (8), the largest communications satellite ever built was lost in November 2002. The failure of one of its launching rockets resulted in the satellite falling in a decaying orbit until it fell into the sea.

Leske, Cavin.

2003-01-01

178

Fluid satellite  

Microsoft Academic Search

Rotating planet and satellite systems with large mass ratios are examined in terms of the stability of the systems, particularly for conditions which result in the formation of planet-moon systems such as Pluto-Charon. The planet is modeled as a Maclaurin spheroid massive enough to experience little influence by the satellite. Several equilibrium sequences are calculated for the shapes which can

I. Hachisu; Y. Eriguchi

1985-01-01

179

Satellite Tracker  

NSDL National Science Digital Library

Students use satellite tracking software available on the Internet to monitor a very large satellite, the International Space Station. Using information from this online resource, students predict and graph the motion of the space station at their location and create a 3-D display of its path through the sky.

Integrated Teaching And Learning Program

180

Communication satellite services for special purpose users  

NASA Technical Reports Server (NTRS)

The present study identifies potential satellite services, examines the technology necessary for efficient implementation of these services, and determines minimum service cost versus user network size. The generic satellite services evaluated comprise TV and radio distribution (for retransmission), video teleconferencing (interactive), audio/facsimile teleconferencing (interactive), multiplexed data/voice (point-to-point), and satellite-supported land mobile. Satellite costs are based on extrapolations from ongoing commercial satellite programs. Production methods, new technology, and effect of production quantities on present and future production costs are examined to provide information on earth station equipment cost versus the variable 'buy'. Six different launch vehicles from a Delta 2914 to a dedicated Shuttle and three frequency bands and both broadcast (no eclipse capability) and fixed service satellites are considered to assess the effect of satellite size on cost and performance. It is assumed that the user pays only for his prorata share of the space segment costs.

Wright, D. L.; Kiesling, J. D.

1977-01-01

181

Navigation satellites  

NASA Astrophysics Data System (ADS)

The evolution, capabilities and uses of satellite-based navigation systems are explored, with emphasis on the accompanying space- and earth-based technologies. Early measurements of the Doppler shifts of Sputnik signals spurred development of the Transit satellite system as a precision navigation aid for Polaris submarines. The development of gravimetric programs to project the actual position of the satellites and the use of high frequency signals to offset ionospheric interference are noted. The design features, performances, and numerous launch and operational failures, of successive Transit spacecraft, i.e., the 5BN, 5C1 and Oscar satellites, are summarized. Details of the operational parameters and design features of the prototype and planned NAVSTAR GPS system are outlined, and plans for a SARSAT search and rescue satellite and the commercial GEOSTAR radionavigation and positioning system are described.

Weiffenbach, George C.

182

American Radio Works: Power Trips  

NSDL National Science Digital Library

Under rules enacted in 1995, members of Congress are effectively banned from accepting any gift worth more than $50, though as this latest investigative radio series from the American RadioWorks team demonstrates, it would appear that members of the House or Senate are still taking many trips at no cost. Working in tandem with a group of graduate students at Northwestern University's Medill School of Journalism, the team catalogued every privately sponsored trip taken by members of Congress since 2000. They discovered that more than $14 million was spent by universities, corporations, and other groups to take these influential persons to a variety of meetings, presentations, and other functions. On this site, visitors can listen to the complete radio presentation, along with obtaining information about how much their own representatives travel and who accepts the most money in trips. Overall, this site is quite informative and more than a bit provocative.

183

A Low-Cost Spread-Spectrum Packet Radio  

Microsoft Academic Search

The goal of the Low Cost Packet Radio (LPR) Program funded by DARPA, via a contract through CECOM, Contract No. DAAK80-81-C-0213, and being developed by Hazeltine Corporation, is a packet radio unit with low cost, low weight, low volume, low power, and high reliability. The LPR consists of a digitally controlled spread spectrum radio and a microprocessor acting as a

D. Behrman; W. C. Fifer

1982-01-01

184

Controlling satellite communication system unwanted emissions in congested RF spectrum  

NASA Astrophysics Data System (ADS)

The International Telecommunication Union (ITU), a United Nations (UN) agency, is the agency that, under an international treaty, sets radio spectrum usage regulations among member nations. Within the United States of America (USA), the organization that sets regulations, coordinates an application for use, and provides authorization for federal government/agency use of the radio frequency (RF) spectrum is the National Telecommunications and Information Administration (NTIA). In this regard, the NTIA defines which RF spectrum is available for federal government use in the USA, and how it is to be used. The NTIA is a component of the United States (U.S.) Department of Commerce of the federal government. The significance of ITU regulations is that ITU approval is required for U.S. federal government/agency permission to use the RF spectrum outside of U.S. boundaries. All member nations have signed a treaty to do so. U.S. federal regulations for federal use of the RF spectrum are found in the Manual of Regulations and Procedures for Federal Radio Frequency Management, and extracts of the manual are found in what is known as the Table of Frequency Allocations. Nonfederal government and private sector use of the RF spectrum within the U.S. is regulated by the Federal Communications Commission (FCC). There is a need to control "unwanted emissions" (defined to include out-of-band emissions, which are those immediately adjacent to the necessary and allocated bandwidth, plus spurious emissions) to preclude interference to all other authorized users. This paper discusses the causes, effects, and mitigation of unwanted RF emissions to systems in adjacent spectra. Digital modulations are widely used in today's satellite communications. Commercial communications sector standards are covered for the most part worldwide by Digital Video Broadcast - Satellite (DVB-S) and digital satellite news gathering (DSNG) evolutions and the second generation of DVB-S (DVB-S2) standard, developed by the European Telecommunications Standards Institute (ETSI). In the USA, the Advanced Television Systems Committee (ATSC) has adopted Europe's DVB-S and DVB-S2 standards for satellite digital transmission. With today's digital modulations, RF spectral side lobes can extend out many times the modulating frequency on either side of the carrier at excessive power levels unless filtered. Higher-order digital modulations include quadrature phase shift keying (QPSK), 8 PSK (8-ary phase shift keying), 16 APSK (also called 12-4 APSK (amplitude phase shift keying)), and 16 QAM (quadrature amplitude modulation); they are key for higher spectrum efficiency to enable higher data rate transmissions in limited available bandwidths. Nonlinear high-power amplifiers (HPAs) can regenerate frequency spectral side lobes on input-filtered digital modulations. The paper discusses technologies and techniques for controlling these spectral side lobes, such as the use of square root raised cosine (SRRC) filtering before or during the modulation process, HPA output power back-off (OPBO), and RF filters after the HPA. Spectral mask specifications are a common method of the NTIA and ITU to define spectral occupancy power limits. They are intended to reduce interference among RF spectrum users by limiting excessive radiation at frequencies beyond the regulatory allocated bandwidth.The focus here is on the communication systems of U.S. government satellites used for space research, space operations, Earth exploration satellite services (EESS), meteorological satellite services (METSATS), and other government services. The 8025 to 8400 megahertz (MHz) X band can be used to illustrate the "unwanted emissions" issue. 8025 to 8400 MHz abuts the 8400 to 8450 MHz band allocated by the NTIA and ITU to space research for space-to-Earth transmissions such as receiving very weak Deep Space Network signals. The views and ideas expressed in this paper are those of the authors and do not necessarily reflect those of The Aerospace Corporation or The National Oceanic and Atmosphe

Olsen, Donald; Heymann, Roger

2007-09-01

185

Virtual radios  

Microsoft Academic Search

Conventional software radios take advantage of vastly improved analog to digital converters (ADCs) and digital signal processing (DSP) hardware. Our approach, which we refer to as virtual radios, also depends upon high performance ADCs. However, rather than use DSPs, we have chosen to ride the curve of rapidly improving workstation hardware. We use wideband digitization and then perform all of

Vanu Bose; Michael Ismert; Matt Welborn; John Guttag

1999-01-01

186

College Radio.  

ERIC Educational Resources Information Center

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

Sauls, Samuel J.

187

Ionospheric effects on C3I satellite communications systems in Greenland  

NASA Astrophysics Data System (ADS)

The effects of polar ionospheric scintillation fading on U.S. military satellite communications systems in Greenland are reviewed. The operational type of satellite communications testing, conducted for the past 10 years to evaluate the feasibility of replacing the traditional HF radio links with satellite communications links is described. Some future plans for the operational use of satellite communications in Greenland are identified.

Johnson, A.; Taagholt, J.

1985-06-01

188

The American mobile satellite system  

NASA Astrophysics Data System (ADS)

During 1989, the American Mobile Satellite Corporation (AMSC) was authorized to construct, launch, and operate satellites to provide mobile satellite services (MSS) to the U.S. and Puerto Rico. The AMSC has undertaken three major development programs to bring a full range of MSS services to the U.S. The first program is the space segment program that will result in the construction and launch of the satellites as well as the construction and installation of the supporting ground telemetry and command system. The second segment will result in the specification, design, development, construction, and installation of the Network Control System necessary for managing communications access to the satellites, and the specification and development of ground equipment for standard circuit switched and packet switched communications services. The third program is the Phase 1 program to provide low speed data services within the U.S. prior to availability of the AMSC satellites and ground segment. Described here are the present status and plans for these three programs as well as an update on related business arrangements and regulatory matters.

Garner, William B.

189

The American mobile satellite system  

NASA Technical Reports Server (NTRS)

During 1989, the American Mobile Satellite Corporation (AMSC) was authorized to construct, launch, and operate satellites to provide mobile satellite services (MSS) to the U.S. and Puerto Rico. The AMSC has undertaken three major development programs to bring a full range of MSS services to the U.S. The first program is the space segment program that will result in the construction and launch of the satellites as well as the construction and installation of the supporting ground telemetry and command system. The second segment will result in the specification, design, development, construction, and installation of the Network Control System necessary for managing communications access to the satellites, and the specification and development of ground equipment for standard circuit switched and packet switched communications services. The third program is the Phase 1 program to provide low speed data services within the U.S. prior to availability of the AMSC satellites and ground segment. Described here are the present status and plans for these three programs as well as an update on related business arrangements and regulatory matters.

Garner, William B.

1990-01-01

190

Radio Relays Improve Wireless Products  

NASA Technical Reports Server (NTRS)

Signal Hill, California-based XCOM Wireless Inc. developed radio frequency micromachine (RF MEMS) relays with a Phase II Small Business Innovation Research (SBIR) contract through NASA?s Jet Propulsion Laboratory. In order to improve satellite communication systems, XCOM produced wireless RF MEMS relays and tunable capacitors that use metal-to-metal contact and have the potential to outperform most semiconductor technologies while using less power. These relays are used in high-frequency test equipment and instrumentation, where increased speed can mean significant cost savings. Applications now also include mainstream wireless applications and greatly improved tactical radios.

2009-01-01

191

Satellite Imagery  

NSDL National Science Digital Library

This undergraduate meteorology tutorial focuses on the use of satellite imagery by forecasters. Different types of imagery are discussed, followed by training on the identification of particular types of weather systems.

Nielsen-Gammon, John

1996-01-01

192

Satellite Images  

NSDL National Science Digital Library

In this online, interactive module, students learn about the three types of satellite images (visible, infrared, and water vapor); how to identify basic cloud types and storm systems in satellite images; and demonstrate the basic knowledge necessary to interpret satellite observations. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

193

Satellite Videoconferences  

NASA Technical Reports Server (NTRS)

NASA is helping thousands of teachers to learn more about aerospace matters, improve their classroom skills, and expand significantly the content of their aerospace education curricula by means of live educational satellite videoconferences. The 1 1/2 hour 'Update for Teachers' programs originate at Oklahoma State University (OSU) Telecommunications Center. The television signals are transmitted to the WESTAR IV communications satellite, which remits them to participating schools across the U.S. and in parts of Mexico and Canada. The schools are equipped with small home style satellite reception dishes. Education Satellite Videoconference programs are conducted four times yearly, covering a variety of aerospace subjects. Teachers can call toll-free and have questions answered after the speaker's presentations. Information about NASA educational resources and how to obtain them will be provided.

1990-01-01

194

3 - 13 ?m Spectra of Geosynchronous Satellites  

NASA Astrophysics Data System (ADS)

We report 3-13 ?m spectra of three geosynchronous satellites using The Aerospace Corporation's Broadband Array Spectrograph System (BASS) on the AEOS 3.7 meter telescope at Haleakala in December 2005. The satellites observed were NORAD 21639 (TDRS 5), 11145 (DSCS 2-12) and 15629 (INTELSAT 510). The spectra showed structure indicative of the satellites' surface material, temperature and cross section as viewed from the observatory. A brief summery of how to analyze such spectra to retrieve surface material composition, temperature and geometrical cross section is included.

Lynch, D.; Russell, R.; Rudy, R.; Gutierrez, D.; Turpin, M.; Crawford, K.; Dotan, Y.; Kim, D.; Skinner, M.

195

Kids Development Corporation.  

ERIC Educational Resources Information Center

Kids Development Corporation is a simulation of economic life appropriate for gifted students in grades 4-11, in which students form a corporation; purchase land; learn about building construction, banking, and investing; create a logo; and develop a community. This article describes the program's goals and objectives, schedule of activities, and

Davison, Betty

1993-01-01

196

Bottle Rock Power Corporation  

E-print Network

Bottle Rock Power Corporation 1275 4th Street, No. 105 Phone: 707.541.0976 Santa Rosa, CA 95404 Fax 1516 9th Street, MS-2000 Sacramento, CA 95814-5512 RE: Bottle Rock Power Plant (79-AFC-4C) Petition for Extending Environmental Monitoring Program Dear Ms. Tronaas: The Bottle Rock Power Corporation (BRPC

197

Corporate Affiliate Event Details  

E-print Network

2013 Corporate Affiliate PROPOSAL #12;Event Details Date: October 3-4, 2013 Location: Northwestern Counsel Institute Affiliate Program? Affiliates of the Corporate Counsel Institute (CCI) are law firms and marketing benefits. Extend this highly-regarded educational oppor- tunity throughout your organization

Shahriar, Selim

198

Satellite-to-satellite Doppler measurements for use in ionospheric research  

NASA Astrophysics Data System (ADS)

A general expression has been derived for the Doppler shift of radio signals transmitted between two satellites at VHF and above. The Doppler shift is shown to depend on (1) the rate of change of the free space path between the satellites; (2) the mean velocity of the satellites and the integrated electron density gradients, both perpendicular to the line-of-sight between the satellites; (3) the moment of the perpendicular gradients and the deviations of the individual satellite perpendicular velocities from the mean; and (4) the line-of-sight velocity components and electron density values at each satellite. Different terms of the expression are shown to dominate under varying conditions; ionospheric irregularities will result in modifications of the Doppler shift expression. The case of oblique propagation between two satellites is examined at MF and HF to estimate the experimental accuracy required to measure ionospheric velocities.

Dyson, P. L.; Bennett, J. A.

199

The Mexican national satellite system  

NASA Astrophysics Data System (ADS)

The satellites, tracking, telemetry, command, and monitoring facilities, and the earth station complex for the Mexican national satellite system, Morelos, are described. The spacecraft are intended to provide educational television, rural telephony, data transmission, and business and industrial services. Scheduled for 1985 launch, the satellites will be placed in GEO and use the C and Ku bands with 12 narrow band and six wideband transponders. Spin-stabilized and solar cell powered, the functional mass will be 666 kg, including propellant. The solar panels will provide 940 W of power and 830 W will be available from NiCd batteries during eclipse conditions. The earth station will be located at Iztapalapa, which will have a 12 m antenna, redundant uplink and downlink radios, and command and ranging equipment. Back-up capability will be provided by a station at Tulancingo. Ku band and C band stations are in planning.

Sanchez Ruiz, M. E.; Briskman, R. D.

1983-10-01

200

Satellite Winds  

NSDL National Science Digital Library

In this online, interactive module, students learn about the using successive satellite observations of clouds to determine wind direction and speed. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

201

Essays in corporate finance  

E-print Network

This thesis consists of three essays covering topics in empirical corporate finance with an emphasis on banking relationships and its effect on liquidity constraints and business growth. In particular, it investigates the ...

Drexler, Alejandro Herman

2009-01-01

202

Encyclopedia of Corporate Governance  

NSDL National Science Digital Library

Encyclopedia of Corporate Governance, or encycogov for short, is created and maintained by Henrik Mathiesen, a PhD candidate at the Department of International Economics and Management at the Copenhagen Business School. Content on the site is divided into two sections: Specific Topics and General Topics. Topics in both sections begin with a paragraph explaining the overarching definition of the principle, and link to a variety of tables, "exhibitions," and models that further illustrate the definition. For example, the Bankruptcy Systems section begins with the definition and is followed up by two tables: "Effects of bankruptcy systems on corporate performance and other kinds of institutions of relevance for corporate governance" and "International corporate governance- Tentative characterizations of legal and empirical state of large firm bankruptcy systems in various countries as of 1980-95: 1) Developing countries. 2)Germany. 3) Japan. 4) Anglo-American countries. 5) Denmark." Also included on the site are references and site users information.

203

Satellite Telecommunications.  

ERIC Educational Resources Information Center

This issue of a quarterly publication of the Council of Europe covers aspects of the history, technology, policies, and impact of telecommunications in Europe, with an emphasis on European television. The following articles are included: (1) "Man and the World of Telecommunications" (Piet Stoffelen); (2) "The European Communications Satellite

Forum, 1986

1986-01-01

204

Satellite Footprint.  

ERIC Educational Resources Information Center

A brief overview of the use of satellites in education mentions sources of information about their use and available programing. There is a review of the technological aspects of the Europlus Network, which markets European programing to viewers in the U.S. via Intelsat. (CNP)

Siskin, Marc Neil

1993-01-01

205

Benchmarking Corporate Energy Management  

E-print Network

management practices at the corporate to energy manager levels. THE ENERGY TO OUTPUT INDEX It would be nice ifthere were a simple quantitative measure to how well a company managed its energy One measure that is often used is energy use per unit...BENCHMARKING CORPORATE ENERGY MANAGEMENT Dr. Douglas L. Norland Director of Research and Industrial Programs Alliance to Save Energy Washington, DC ABSTRACT There is growing interest among energy managers in finding out how their company...

Norland, D. L.

206

Satellite systems for Latin American telecommunication requirements  

NASA Astrophysics Data System (ADS)

Aspects of satellite telecommunications systems of interest to Latin America are discussed. Presently existing systems are described, including both state-run and international services. Services planned for the region are examined, including Geostar, a service that provides satellite radio determination and message services, a system which will provide a high-capacity digital voice and data service for airlines, and direct broadcast satellites. Applications of these systems in education, rural telephony, data transmission, news services, publishing, emergency communications, and mobile communications are addressed.

Elizondo, Eduardo L.

207

Nanosail-D: The Small Satellite That Could!  

NASA Technical Reports Server (NTRS)

Three years from its initial design review, NanoSail-D successfully deployed its sail on January 20th, 2011. It became the first solar sail vehicle to orbit the earth and the second sail ever unfurled in space. The NanoSail-D mission had two main objectives: eject a nanosatellite from a microsatellite; deploy its sail from a highly compacted volume and low mass system to validate large structure deployment and potential de-orbit technologies. These objectives were successfully achieved and the de-orbit analysis is in process. This paper presents an overview of the NanoSail-D project and insights into how potential setbacks were overcome. Many lessons have been learned during these past three years and are discussed in light of the phenomenal success and interest that this small satellite has generated. NanoSail-D was jointly designed and built by NASA's Marshall Space Flight Center and NASA's Ames Research Center. ManTech/NeXolve Corporation also provided key sail design support. The NanoSail-D experiment is managed by Marshall and jointly sponsored by the Army Space and Missile Defense Command, the Von Braun Center for Science and Innovation and Dynetics Inc. Ground operations support was provided by Santa Clara University, with radio beacon packets received from amateur operators around the world.

Alhorn, Dean C.; Casas, Joseph P.; Agasid, Elwood F.; Adams, Charles L.; Laue, Greg; Kitts, Christopher; O'Brien, Sue

2011-01-01

208

The Corporate Library  

NSDL National Science Digital Library

Launched in the summer of 1999 by two long-term partners in Lens Investment Management, this site "is intended to serve as a central repository for research, study and critical thinking about the nature of the modern global corporation, with a special focus on corporate governance and the relationship between company management, their boards and their shareowners." Along with current awareness articles from the staff of The Corporate Library (TCL) and outside sources including Harvard Business School Working Knowledge, CBSMarketWatch, and McKinsey and Co., the site also provides in-depth special reports on CEO Contracts and on Corporate Governance and Performance. The full-text of Power and Accountability, the book written by The Corporate Library's founders Robert AG Monks and Nell Minow, is also available free of charge. In addition, users may search the entire TCL catalog, which includes 25 years' worth of articles emphasizing the best practices in a variety of areas including disclosure and governance and corporate standing.

Minow, Nell.; Monks, Robert A.

209

Propagation effects on radio range and noise in earth-space telecommunications  

Microsoft Academic Search

Deep-space missions and radio navigation satellite operations place high requirements upon the precision of range and Doppler frequency measurements and may be sensitive to even small increases in radio noise. For paths to geostationary satellites and beyond, the excess range delay due to the ionosphere and plasmasphere is proportional to the total electron content along the path and inversely proportional

W. L. Flock; S. D. Slobin; E. K. Smith

1982-01-01

210

Persons, Things and Corporations: The Corporate Personality Controversy and Comparative Corporate Governance  

Microsoft Academic Search

The present article is a fresh attempt to 'end' the age-old controversy on the nature of corporate personality by declaring victory for both corporate nominalism and corporate realism. The key to this claim is the observation that an incorporated business firm is composed of not one but two ownership relations: the shareholders own the corporation as a legal thing and

Katsuhito Iwai

1997-01-01

211

Passive synthesis of the antenna aperture for satellite systems  

NASA Astrophysics Data System (ADS)

The possibility of passive synthesis of the antenna aperture for satellite systems of monitoring ground-based radio radiation sources is discussed. Experimental data on the inverse passive synthesis on the Space-Earth paths are presented for reception of GPS navigation satellite radiation. The data confirm the possibility of developing the passive synthesized aperture radar and interference phase signal processing.

Shumskii, P. O.; Meshcheryakov, A. A.; Sharygin, G. S.

2012-08-01

212

Aeronautical mobile satellite service: Air traffic control applications  

NASA Astrophysics Data System (ADS)

Canada's history both in aviation and in satellite communications development spans several decades. The introduction of aeronautical mobile satellite communications will serve our requirements for airspace management in areas not served by line-of-sight radio and radar facilities. The ensuing improvements in air safety and operating efficiency are eagerly awaited by the aviation community.

Sim, Dave

213

Aeronautical mobile satellite service: Air traffic control applications  

NASA Technical Reports Server (NTRS)

Canada's history both in aviation and in satellite communications development spans several decades. The introduction of aeronautical mobile satellite communications will serve our requirements for airspace management in areas not served by line-of-sight radio and radar facilities. The ensuing improvements in air safety and operating efficiency are eagerly awaited by the aviation community.

Sim, Dave

1990-01-01

214

Satellite Doppler data processing using a microcomputer  

NASA Technical Reports Server (NTRS)

A microcomputer which was developed to compute ground radio beacon position locations using satellite measurements of Doppler frequency shift is described. Both the computational algorithms and the microcomputer hardware incorporating these algorithms were discussed. Results are presented where the microcomputer in conjunction with the NIMBUS-6 random access measurement system provides real time calculation of beacon latitude and longitude.

Schmid, P. E.; Lynn, J. J.

1977-01-01

215

Radio Tagged Adult Female Walrus on Ice Floe  

USGS Multimedia Gallery

Adult female walrus on ice floe photographed shortly after receiving a behavior monitoring satellite-linked radio tag from USGS researchers. Data acquired from such radio-tags are providing insights on the distribution and behavior of Pacific walruses during a time when their summer sea ice h...

216

Radio Tracking of Solar Energetic Particles through Interplanetary Space.  

PubMed

Energetic particles ejected from the sun generate radio waves as they travel out through the interplanetary medium. Satellite observations of this emission at long radio wavelengths provide a means of investigating properties of the interplanetary medium, including the gross magnetic field configuration over distances of 1 astronomical unit. Results of such observations are illustrated. PMID:17798539

Fainberg, J; Evans, L G; Stone, R G

1972-11-17

217

Near-Infrared Spectra of Uranian Satellites  

NASA Astrophysics Data System (ADS)

We present 0.8 to 2.5 micron spectra taken on June 21 & 22, 1998 UT of the Uranian satellites Miranda, Titania, Ariel, Oberon, and Umbriel. The spectra were taken using The Aerospace Corporation's Near-Infrared Imaging Spectragraph (NIRIS) on the University of California's Lick Observatory 3 meter Shane telescope. These spectra will be compared with previous work including Brown, R.H. and Cruikshank, D.P. (1983) as well as more recent spectra and analysis by Grundy, W. et al. (1999). Support for this research was provided by The Aerospace Corporation's Independent Research and Development Program.

Venturini, C. C.; Lynch, D. K.; Rudy, R. J.; Mazuk, S.; Puetter, R. C.

2001-05-01

218

Approved Module Information for EE3RSY, 2014/5 Module Title/Name: Radio Systems and Personal  

E-print Network

and satellite communications. Module Learning Outcomes: Knowledge and Understanding: * mobile communication Communications Systems: Introduce practical radio communications systems such as satellite and mobile Communications Systems Module Code: EE3RSY School: Engineering and Applied Science Module Type: Standard Module

Neirotti, Juan Pablo

219

Telecommunications satellites for developing countries - Extension of satellite use to rural areas  

NASA Astrophysics Data System (ADS)

The potential of telecommunications satellites to improve communications in developing nations, particularly the rural areas, is considered. Requirements for improved telephone, television and radio service in developing nations are indicated, and it is argued that satellites would provide one of the most efficient means of developing networks for telephony, television and radio both for intercity trunk routes and for rural areas. The forms such satellite systems could take for rural telephony and direct, semidirect and redistributed television broadcasting are examined, and an approach to the integration of telephone and television services is proposed. Telephony and television capacity requirements for a typical sub-Saharan country are estimated, and the financial aspects of the systems are considered. It is concluded that satellites can considerably improve the general communications situation in many developing nations, giving vast rural areas access to telecommunications for the first time and with comparatively low funding requirements.

Pinglier, A.

1980-02-01

220

The impact of satellite technology on rural telephone system planning  

NASA Astrophysics Data System (ADS)

Telecommunication system planning and development for rural areas is instrumental in the modernization of developing countries. The maturity of satellite technology in the 1980's will have a strong costing and technical influence in implementing the architecture of such a system. This paper conducts trade-offs among various technologies such as radio, telephone, cable, UHF/VHF radio, switches and satellites for various geographical environments. It then assesses the state and impact of satellite technology in relation so supplementing the existing telephone networks and/or planning a new rural telephony network.

Lusignan, B. B.; Mousa, M. M.; Samarkandy, M. K.; Han, C. C.

221

Numerical Arc-Segmentation Algorithm For A Radio Conference  

NASA Technical Reports Server (NTRS)

NASARC computer program developed from general planning principles and decisions of both sessions of World Administrative Radio Conference on Use of Geostationary Satellite Orbit and on Planning of Space Services Utilizing It (WARC-85 and WARC-88). Written to help countries satisfy requirements for nationwide fixed-satellite services from at least one orbital position within predetermined arc. Written in ANSI standard FORTRAN 77.

Whyte, W. A.; Ponchak, Denise S.; Heyward, A. O.; Zuzek, John E.; Spence, R. L.

1992-01-01

222

Frequency planning issues for direct broadcasting satellites  

NASA Astrophysics Data System (ADS)

In 1963, the International Telecommunication Union (ITU) defined the 'broadcasting satellite service' (BSS), taking into account the possibility of broadcasting directly from satellites to low-cost receiving terminals at individual homes or to more costly terminals at community centers. A World Administrative Radio Conference (WARC) was held in 1977 to carry out planning for the BSS band near 12 GHz. However, the countries of Region 2 (the Americas and Greenland) decided to postpone international BSS planning to a Regional Administrative Radio Conference (RARC) which was held in 1983. Meanwhile, in 1980, the Federal Communications Commission (FCC) began to develop domestic policies and procedures for the BSS. These policies and procedures were published in 1982. The present paper is concerned with the Direct Broadcast Satellite (DBS) frequency planning issues, taking into account the agreements and decisions made by WARC-77, RARC-83, and the FCC.

Reinhart, E. E.

223

Corporate Crime Reporter  

NSDL National Science Digital Library

Published since 1986, the Corporate Crime Reporter is a legal newsletter that highlights recent news items about ongoing corporate crime prosecutions, along with featuring interviews with prominent attorneys who work in this rather intriguing field of law practice. The interview section is quite interesting as users can read long-form interviews with major players such as Dan Webb (who was a prosecutor in the Iran-Contra Affair) and Neil Getnick, who prosecuted the Bayer corporation after it was suspected they bilked Medicaid out of approximately $100 million. Visitors can also view various related documents, such as the indictment of Martha Stewart and a Justice Department memo regarding the federal prosecution of business organizations. The site is rounded out by several reports on the top 10 white-collar crime defense lawyers and the top 100 corporate criminals of the 1990s. Overall, the site will be of great interest to legal professionals, or those who are interested in learning more about the complex world of corporate crime in the United States.

224

A new digital land mobile satellite system  

NASA Astrophysics Data System (ADS)

A description is given of the different digital services planned to be carried over existing and planned mobile satellite systems. These systems are then compared with analog services in terms of bandwidth and power efficiency. This comparison provides the rationale for the establishment of a digital land mobile satellite service (DLMSS) to use frequencies that are currently available but not yet assigned to a domestic mobile satellite system in the United States. The focus here is on the expected advantages of digital transmission techniques in accommodating additional mobile satellite systems in this portion of the spectrum, and how such techniques can fully satisfy voice, data and facsimile mobile communications requirements in a cost effective manner. A description is given of the system architecture of the DMLSS service proposed by the Geostar Messaging Corporation (GMC) and the market potential of DLMSS.

Schneider, Philip

225

A new digital land mobile satellite system  

NASA Technical Reports Server (NTRS)

A description is given of the different digital services planned to be carried over existing and planned mobile satellite systems. These systems are then compared with analog services in terms of bandwidth and power efficiency. This comparison provides the rationale for the establishment of a digital land mobile satellite service (DLMSS) to use frequencies that are currently available but not yet assigned to a domestic mobile satellite system in the United States. The focus here is on the expected advantages of digital transmission techniques in accommodating additional mobile satellite systems in this portion of the spectrum, and how such techniques can fully satisfy voice, data and facsimile mobile communications requirements in a cost effective manner. A description is given of the system architecture of the DMLSS service proposed by the Geostar Messaging Corporation (GMC) and the market potential of DLMSS.

Schneider, Philip

1990-01-01

226

A School Radio Telescope for Two Metres  

ERIC Educational Resources Information Center

Discusses the arrangement, specifications, and operation of a setup designed for use as a student project to record radio storms, continuous level of the quiet sun, and scientific satellites operating near the amateur 2-m band. Included is an example of records of solar activity during 1968-73. (CC)

Codling, J. C.

1973-01-01

227

The Radio JOVE Project - Shoestring Radio Astronomy  

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

228

Satellite broadcast usage and life test of high power S-band Traveling Wave Tube Amplifiers  

NASA Astrophysics Data System (ADS)

Broadcasting radio programs from satellites to mobile users has been operating for many years in the United States, Canada and South Korea. The service, generally called Satellite Radio, is provided at S-band radio frequencies. Satellite Radio users require near perfect service availability. Since most users are mobile (automobiles and handheld reception), the antennas of their receivers have little gain necessitating very high effective isotropic radiated power (EIRP) from the satellite to provide the required availability particularly under fading conditions. Despite using a satellite directive transmitting antenna, the achievement of this high EIRP requires a satellite transmitter radio frequency power output of over 7 kW. This is typically achieved by paralleling 32 Traveling Wave Tube Amplifiers (TWTAs). The configuration, usage and technical aspects of such satellite transmitters are described. These satellite transmitters are critical to Satellite Radio service both for performance and for operating lifetime, typically over 15 years. Because of this importance, detailed lifetime laboratory testing is being done on the TWTAs as reported herein.

Bosch, Ernst; Briskman, Robert D.; Foust, Joseph V.; Huebner, Karl-Heinz; Strauss, Robert

2012-12-01

229

25 CFR 213.14 - Corporations and corporate information.  

Code of Federal Regulations, 2013 CFR

...BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF RESTRICTED LANDS OF MEMBERS OF FIVE CIVILIZED TRIBES, OKLAHOMA, FOR MINING How to Acquire Leases 213.14 Corporations and corporate information....

2013-04-01

230

25 CFR 213.14 - Corporations and corporate information.  

Code of Federal Regulations, 2012 CFR

...BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF RESTRICTED LANDS OF MEMBERS OF FIVE CIVILIZED TRIBES, OKLAHOMA, FOR MINING How to Acquire Leases 213.14 Corporations and corporate information....

2012-04-01

231

25 CFR 213.14 - Corporations and corporate information.  

...AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF RESTRICTED LANDS OF MEMBERS OF FIVE CIVILIZED TRIBES, OKLAHOMA, FOR MINING How to Acquire Leases 213.14 Corporations and corporate information. If the applicant...

2014-04-01

232

25 CFR 213.14 - Corporations and corporate information.  

Code of Federal Regulations, 2010 CFR

...AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF RESTRICTED LANDS OF MEMBERS OF FIVE CIVILIZED TRIBES, OKLAHOMA, FOR MINING How to Acquire Leases 213.14 Corporations and corporate information. If the applicant...

2010-04-01

233

8 LINCOLN LABORATORY JOURNAL n VOLUME 21, NUMBER 1, 2014 InsIghts Into the UnIverse: Astronomy wIth hAystAck's rAdIo telescope  

E-print Network

wIth hAystAck's rAdIo telescope Insights into the Universe: Astronomy with Haystack's Radio Telescope game-changing tech- nology for radio science, and to apply it to the study of our planet, its space projects. The observatory is operated under an agreement with the Northeast Radio Observatory Corporation

Williams, Brian C.

234

Radio-electronic equipment  

NASA Astrophysics Data System (ADS)

The fundamentals of radio electronics are first elaborated, with attention given to the principles of circuits and signals, semiconductor devices, computing techniques, radio transmitters and receivers, and wave propagation. The principles of operation of onboard radio-electronic devices are then described, with emphasis on radio communication systems, radar systems, radio navigation systems, radio control systems, and electronic countermeasures. The maintenance of radio-electronic devices is also discussed.

Boldin, Viktor A.; Gorgonov, Gennadii I.; Konovalov, Viktor D.; Kurilov, N. N.; Levonchuk, V. V.

235

Statement by Harvard Corporation Committee on Shareholder Responsibility (CCSR) Regarding Stock in China Petroleum and Chemical Corporation (Sinopec Corporation)  

E-print Network

, and in light of developments since that decision regarding Sinopec Corporation's involvement in Sudanese oil Corporation and its closely affiliated parent company, China Petrochemical Corporation (Sinopec Group genocide." Having monitored recent developments regarding Sinopec Corporation's involvement in Sudanese oil

236

Satellite positioning  

NASA Astrophysics Data System (ADS)

The Fifth International Geodetic Symposium on Satellite Positioning was held in Las Cruces, N.Mex., March 13-17, 1989. It was cosponsored by the Defense Mapping Agency and the National Geodetic Survey of the National Oceanic and Atmospheric Administration. More than 385 geodesists, engineers, scientists, surveyors, instrument manufacturers, and managers from 32 countries attended the symposium.The keynote address and 96 papers including 9 invited papers and 10 poster papers were presented in the 5-day meeting. In addition, there were three well-attended workshops with lively technical discussions. The invited guest presentations at the symposium luncheon and banquet provided very useful and interesting information.

Stein, William L.; Kumar, Muneendra

237

Corporate social responsibility: an attitude of Ethiopian corporates  

Microsoft Academic Search

Purpose The purpose of this research is to find an attitude of Ethiopian corporate sector towards corporate social responsibility (CSR). In addition this research analyzed the opinion of employees, customers' as well the general public about the Ethiopian corporate sector's socially responsible actions. Design\\/methodology\\/approach This paper reviewed the relevant literature of CSR. Through structured questionnaires and in-depth interviews

Rajasekhara Mouly Potluri; Zelalem Temesgen

2008-01-01

238

The integration of corporate governance in corporate social responsibility disclosures  

Microsoft Academic Search

In recent years, not only has attention to corporate governance increased but also the notion has broadened considerably, and started to cover some aspects traditionally seen as being part of corporate social responsibility (CSR). CSR, corporate governance and their interlink seem particularly relevant for multinational enterprises (MNEs), which, due to their activities in multiple contexts around the world and concomitant

A. Kolk; J. Pinkse

2010-01-01

239

2009 IBM Corporation 2009 IBM Corporation IMS and Java  

E-print Network

1 © 2009 IBM Corporation© 2009 IBM Corporation IMS and Java for Application Modernization Barbara November 4-5, 2009 This presentation discusses use of IMS and Java to modernize your applications. #12;2 2 IMS © 2009 IBM Corporation Agenda Java basics IMS Java basics IMS Java Applications IMS Database

240

Corporate governance and insider trading  

E-print Network

I investigate the relation between corporate governance and insider trading by corporate executives. Despite the general view that trade on non-public information adversely affects capital market participants, the impact ...

Rozanov, Konstantin A

2008-01-01

241

A Survey of Corporate Governance  

Microsoft Academic Search

This article surveys research on corporate governance, with special attention to the importance of legal protection of investors and of ownership concentration in corporate governance systems around the world. Copyright 1997 by American Finance Association.

Andrei Shleifer; Robert W Vishny

1997-01-01

242

The Illiquidity of Corporate Bonds  

E-print Network

This paper examines the illiquidity of corporate bonds and its asset-pricing implications. Using transactions data from 2003 to 2009, we show that the illiquidity in corporate bonds is substantial, significantly greater ...

Bao, Jack

243

Corporate Venture Capital (CVC) Seeking Innovation and  

E-print Network

Corporate Venture Capital (CVC) Seeking Innovation and Strategic Growth Recent patterns in CVC-916 #12;Corporate Venture Capital About This Report This report on corporate venture capital, Technology Innovation Program, National Institute of Standards and Technology #12;Corporate Venture Capital

244

Corporate Gifts & Entertainment  

E-print Network

Corporate Gifts & Entertainment: A Survey of Practices March 2009 Health Care Compliance of lavish executive pay, when it comes to enter- tainment and gift giving, the business world may be far, on the whole, business is fairly restrictive of the gifts employees can give and receive and how they can

Chapman, Michael S.

245

Corporate information management guidance  

SciTech Connect

At the request of the Department of Energy`s (DOE) Information Management (IM) Council, IM representatives from nearly all Headquarters (HQ) organizations have been meeting over the past year as the Corporate Guidance Group (CGG) to develop useful and sound corporate information management (IM) guidance. The ability of the Department`s IM community to develop such unified guidance continues to be critical to the success of future Departmental IM planning processes and the establishment of a well-coordinated IM environment between Headquarters and field organizations. This report, with 26 specific corporate IM guidance items documented and unanimously agreed to, as well as 12 items recommended for further development and 3 items deferred for future consideration, represents a highly successful effort by the IM community. The effort has proven that the diverse DOE organizations can put aside individual preferences and work together towards a common and mutually beneficial goal. In examining most areas and issues associated with information management in the Department, they have developed specific, far-reaching, and useful guidance. The IM representatives recommend that the documented guidance items provided in this report and approved by the DOE IM Council be followed by all IM organizations. The representatives also strongly recommend that the guidance process developed by the CGG be the single process for developing corporate IM guidance.

NONE

1997-08-01

246

Competition and Corporate Performance  

Microsoft Academic Search

Are people right to think that competition improves corporate performance? The author's investigations indicate first that there are some theoretical reasons for believing this hypothesis to be correct but they are not overwhelming. Furthermore, the existing empirical evidence on this question is weak. However, the results reported here, based on the analysis of around 670 U.K. companies, provide some support

Stephen J. Nickell

1996-01-01

247

A corporate supersonic transport  

NASA Technical Reports Server (NTRS)

This talk address the market and technology for a corporate supersonic transport. It describes a candidate configuration. There seems to be a sufficient market for such an aircraft, even if restricted to supersonic operation over water. The candidate configuration's sonic boom overpressure may be small enough to allow overland operation as well.

Greene, Randall; Seebass, Richard

1996-01-01

248

Battery voltage variations and radio transmitter temperatures of the small spacecraft  

NASA Astrophysics Data System (ADS)

Diurnal variations of the storage battery voltages as well as temperatures of the radio transmitters on board the small satellite "Universitetsky" have been revealed. Double-humped dependences have been found, related to changes of the micro satellite position relative to the Earth and the Sun and to the on-board satellite systems' operation.

Shakhparonov, V. M.; Karagioz, O. V.

2014-05-01

249

COMPARATIVE STUDY ON CORPORATE GOVERNANCE  

Microsoft Academic Search

Corporate governance is a key element of today(tm)s economic reality being more and more present in many countries around the world. This paper has two main objectives. The first one is to offer more insight into the concept of corporate governance by a thorough literature review and by presenting and analyzing a framework of corporate governance. The second objective of

Gavrea Corina; Stegerean Roxana

2011-01-01

250

Forestry Commission England Corporate Plan  

E-print Network

Forestry Commission England Corporate Plan 2011-15 This is the Corporate Plan for the Forestry Commission in England. It is one of a suite of plans including those for Forestry Commission (GB) and Forest Research. Page 1Forestry Commission England Corporate Plan 2011-15 #12;Page 2Forestry Commission England

251

The Arctic Regional Communications Small SATellite (ARCSAT)  

NASA Technical Reports Server (NTRS)

Traditional satellite missions are extremely complex and expensive to design, build, test, launch and operate. Consequently many complementary operational, exploration and research satellite missions are being formulated as a growing part of the future space community capabilities using formations of small, distributed, simple to launch and inexpensive highly capable small scale satellites. The Arctic Regional Communications small SATellite (ARCSAT) initiative would launch a Mini-Satellite "Mothership" into Polar or Sun Sync low-earth-orbit (LEO). Once on orbit, the Mothership would perform orbital insertion of four internally stored independently maneuverable nanosatellites, each containing electronically steerable antennas and reconfigurable software-defined radios. Unlike the traditional geostationary larger complex satellite communication systems, this LEO communications system will be comprised of initially a five small satellite formation that can be later incrementally increased in the total number of satellites for additional data coverage. ARCSAT will provide significant enabling capabilities in the Arctic for autonomous voice and data communications relay, Maritime Domain Awareness (MDA), data-extraction from unattended sensors, and terrestrial Search & Rescue (SAR) beacon detection missions throughout the "data starved desert" of the Arctic Region.

Casas, Joseph; Kress, Martin; Sims, William; Spehn, Stephen; Jaeger, Talbot; Sanders, Devon

2013-01-01

252

Satellite altimetry  

NASA Technical Reports Server (NTRS)

Since altimetry data are not really old enough to use the term data archaeology, Mr. Cheney referred to the stewardship of these data. He noted that it is very important to document the basis for an altimetry data set as the algorithms and corrections used to arrive at the Geophysical Data Record (GDR) have been improving and are continuing to improve the precision of sea level data derived from altimetry. He noted that the GEOSAT Exact Repeat Mission (ERM) data set has recently been reprocessed by his organization in the National Ocean Service of NOAA and made available to the scientific community on CD/ROM disks by the National Oceanographic Data Center of the U.S. (NODC). The new data set contains a satellite orbit more precise by an order of magnitude together with an improved water vapor correction. A new, comprehensive GDR Handbook has also been prepared.

Cheney, Robert E.

1992-01-01

253

Radio tracking of solar energetic particles through interplanetary space.  

NASA Technical Reports Server (NTRS)

Satellite observations of traveling solar radio bursts provide information about the propagation of energetic solar particles through interplanetary space. This information leads to data on the solar wind density and gross magnetic field configuration over distances of 1 AU. By placing a radio telescope well above the ionosphere it is possible to observe the radio emission down to frequencies that correspond to emission at distances of the order of 1 AU. The observations reported provide the first 'radio picture' over 1 AU of the spiral magnetic field configuration in interplanetary space.

Fainberg, J.; Evans, L. G.; Stone, R. G.

1972-01-01

254

Propagation considerations in the American Mobile Satellite system design  

NASA Astrophysics Data System (ADS)

An overview of the American Mobile Satellite Corporation (AMSC) mobile satellite services (MSS) system with special emphasis given to the propagation issues that were considered in the design is presented. The aspects of the voice codec design that effect system performance in a shadowed environment are discussed. The strategies for overcoming Ku-Band rain fades in the uplink and downlink paths of the gateway station are presented. A land mobile propagation study that has both measurement and simulation activities is described.

Kittiver, Charles; Sigler, Charles E., Jr.

1993-08-01

255

Outer planet satellites  

NASA Technical Reports Server (NTRS)

Recent findings on the outer-planet satellites are presented, with special consideration given to data on the rheologic properties of ice on icy satellites, the satellite surfaces and exogenic processes, cratering on dead cratered satellites, volcanism, and the interiors of outer-planet satellites. Particular attention is given to the state of Titan's surface and the properties of Triton, Pluto, and Charon.

Schenk, Paul M.

1991-01-01

256

Essays in Corporate Finance  

E-print Network

-firms with local institutional investors are less likely to engage in empire building, to lead the quiet life, and to engage in corporate misbehavior such as earnings management and option backdating (Chhaochharia, Kumar, and Niessen-Ruenzi (2012)). The third... information output, and Bernile, Kumar, and Sulaeman (2011) show that Reg FD eliminated the information advantage of local institutional investors, both of which would suggest weakening or disappearing of our finding after the implementation of Reg FD under...

Zhang, Jun

2014-06-02

257

The United States regional mobile satellite system  

NASA Astrophysics Data System (ADS)

Commercial interests within the United States and Canada are preparing to implement cooperative systems that will provide land and aeronautical mobile satellite services in those two countries and in Mexico. Wide bandwidth, linear satellites ('bent pipe transponders') in geostationary orbit will be built and operated by a consortium of companies in the United States. The consortium will act as a carrier's carrier, leasing bandwidth and power to resellers and private radio leasees who will tailor the ground systems and signal characteristics to the needs of end users. A variety of voice, data, and position fixing services will add new dimensions to mobile communications throughout North America.

Anderson, Roy E.; Cooperman, Richard S.

258

InProc.oftheTheFullyNetworkedCarWorkshop,GenevaInternationalMotorShow,Geneva,Switzerland,March34,2010. Opportunistic Vehicular Networks by Satellite Links  

E-print Network

applications, based on satellite communication links (i.e., LEO/MEO satellite constellations). In such scenario,2010. Opportunistic Vehicular Networks by Satellite Links for Safety Applications A.M. Vegni1 , C. Vegni2 , and T, Boston, MA tdcl@ bu.edu Satellite radio is one of a complementary set of network connectivity

259

The Radio Occultation Processing Package ROPP  

NASA Astrophysics Data System (ADS)

This paper describes the Radio Occultation Processing Package, ROPP, a product of the EUMETSAT Radio Occultation Meteorology Satellite Application Facility (ROM SAF) developed by a large number of scientists over many years. A brief review of the concepts, functionality and structure of ROPP is followed by more detailed descriptions of its key capabilities. Example results from a full chain of processing using some of the ROPP tools are presented. Some current and prospective uses of ROPP are given. Instructions on how to access the code and its supporting documentation are provided.

Culverwell, I. D.; Lewis, H. W.; Offiler, D.; Marquardt, C.; Burrows, C. P.

2015-01-01

260

Satellite observations of transionospheric pulse pairs  

SciTech Connect

The BLACKBEARD payload aboard the ALEXIS satellite has been making broadband observations in the VHF band of the radio spectrum. Since November of 1993 several hundred unusual signals have been recorded. The peculiar nature of these bursts of radio noise is that they have a duration of approximately 10 {mu}sec, are typically 20 to 40 dB brighter than the average background, and occur in pairs separated by approximately 50 {mu}sec. The authors have dubbed these emissions TransIonospheric Pulse Pairs, or TIPP events. They do not know what the source of these emissions is, but the dispersion of these signals is consistent with an origin at or near the earth`s surface. The satellite field of view and time of day when TIPP events are generally detected are consistent with regions of thunderstorm activity such as south-central Africa or Indonesia. 4 refs., 5 figs.

Holden, D.N.; Munson, C.P.; Devenport, J.C. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States)

1995-04-15

261

12 CFR 704.11 - Corporate Credit Union Service Organizations (Corporate CUSOs).  

Code of Federal Regulations, 2011 CFR

...corporate CUSO. This opinion must address factors that have led courts to pierce the corporate veil, such as inadequate...corporate CUSO. This opinion must address factors that have led courts to pierce the corporate veil, such as...

2011-01-01

262

OECD Principles of Corporate Governance  

NSDL National Science Digital Library

The "Organisation for Economic Co-operation and Development Principles of Corporate Governance" sets out a structure for directing and controlling corporate businesses. This document (html or .pdf) consists of five sections detailing the principles: "The rights of shareholders," "The equitable treatment of shareholders," "The role of stakeholders in corporate governance," "Disclosure and transparency," and "The responsibilities of the board," as well as annotations for each of the sections. Be sure to visit the OECD Principles of Corporate Governance Q&A page, linked at the top of the page.

263

Low cost satellite land mobile service for nationwide applications  

NASA Technical Reports Server (NTRS)

A satellite land mobile system using mobile radios in the UHF band, and Ku-band Communications Routing Terminals (earth stations) for a nationwide connection from any mobile location to any fixed or mobile location, and from any fixed location to any mobile location is proposed. The proposed nationwide satellite land mobile service provides: telephone network quality (1 out of 100 blockage) service, complete privacy for all the users, operation similar to the telephone network, alternatives for data services up to 32 Kbps data rates, and a cost effective and practical mobile radio compatible with system sizes ranging from 10,000 to 1,000,000 users. Seven satellite alternatives (ranging from 30 ft diameter dual beam antenna to 210 ft diameter 77 beam antenna) along with mobile radios having a sensitivity figure of merit (G/T) of -15 dB/deg K are considered. Optimized mobile radio user costs are presented as a function of the number of users with the satellite and mobile radio alternatives as system parameters.

Weiss, J. A.

1978-01-01

264

International Finance Corporation  

NSDL National Science Digital Library

As a part of the World Bank, the stated vision of the International Finance Corporation (IFC) is "that poor people have the opportunity to escape poverty and to improve their lives." To whit, the IFC works to promote open and competitive markets in developing countries, generate productive jobs and deliver basic services, among other things. First-time visitors will find that the layout of the site is visually stimulating and quite user-friendly. Visitors can use the embedded search engine to look for specific materials of interest.

265

GEOSAT Follow-On Radar Altimeter Satellite Performance Studies  

NASA Astrophysics Data System (ADS)

Under a Navy Contract with Ball Aerospace and Technologies Corporation, the first GFO satellite was completed in 1997 and launched on 10 February 1998 on an Orbital Taurus launch vehicle. The satellite was operationally accepted on 29 November 2000. With an anticipated 8-year or more life, GFO (http://gfo.bmpcoe.org/Gfo) is a DoD satellite mission managed by the Space and Naval Warfare Systems Command's (SPAWAR's) Meteorological and Oceanographic (METOC) Systems Program Office (PMW 155) located in San Diego, California. The satellite is in the same Exact Repeat Orbit (ERO) as the original GEOSAT (800 km by 108 degrees inclination). All GFO's data products are available to the scientific community and are distributed by NOAA's Laboratory for Satellite Altimetry. The primary program objective was to develop an operational series of radar altimeter satellites to maintain continuous ocean observation for accurate global measurements of both mesoscale and basin-scale oceanography. Since its acceptance, Computer Sciences Corporation (CSC), under contract with the Navy, has provided a team known as the GFO Cal/Val and assisted by NASA and NOAA personnel has undertaken extensive and continuing calibration and validation activities on an exact repeat cycle basis. This paper will discuss the results of those Cal/Val efforts and present charts showing the performance history of the satellite, its sensors (both the Radar Altimeter and the Water Vapor Radiometer), and other relevant performance measures such as orbit accuracy.

Finkelstein, J. L.; Rau, M.; McMillan, J. D.

2002-12-01

266

Educative Activities of the Canadian Broadcasting Corporation and the National Film Board of Canada. New Technologies in Canadian Education Series. Paper 8.  

ERIC Educational Resources Information Center

The Canadian Broadcasting Corporation (CBC) is Canada's publicly-owned broadcast network that provides programming to both English and French national television and AM/FM radio networks. While the CBC was not designed to fill a formal education role in Canada, it does broadcast informative radio and television programs on a complete range of

Swan, Susan

267

The Cassini Radio Science Observations of the Enceladus Plasma Cloud  

NASA Astrophysics Data System (ADS)

Cassini Radio Science Subsystem (RSS) observations of the plasma environment of Enceladus from the radio occultation of 26 January 2006 are reported. The radio occultation technique was used to measure the electron content as a function of distance along a the orbital path of Enceladus with the radio line-of-sight passing about 45 km below the South Pole. The RSS observations, when applied to a toroidal model of a plasma cloud along the orbit of Enceladus show a significant enhancement of the electron density, extending out to distances from the satellite in excess of 88 Enceladus radii in both directions. Simple estimates show that this is consistent with a photoionization plasma source together with transport away from the satellite due to the plasma flow. In addition, the occultation data shows an electron density depletion near the plume, in agreement with other instruments, and this is possibly due to electron attachment to grains.

Kliore, A. J.; Nagy, A. F.; Cravens, T.; Anabtawi, A.

2013-12-01

268

Radio frequency detection assembly and method for detecting radio frequencies  

DOEpatents

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.

Cown, Steven H. (Rigby, ID); Derr, Kurt Warren (Idaho Falls, ID)

2010-03-16

269

Greening corporate identity: CSR online corporate identity reporting  

Microsoft Academic Search

Purpose The purpose of this paper is to explore the motivations for and the impact of corporate social responsibility (CSR) online reporting on organisational identity development and stakeholder relationship management through corporate web communication and information strategies. Design\\/methodology\\/approach A content analysis method is utilised to critique evidence of the use and impact of online CSR reporting in three

Deborah Rolland; Jana O'Keefe Bazzoni

2009-01-01

270

The interrelationship between corporate income tax and corporate social responsibility  

Microsoft Academic Search

Purpose The purpose of this paper is to discuss the interrelationship between corporate income tax (CIT) and corporate social responsibility (CSR) within the international framework of the European Union (EU). Design\\/methodology\\/approach The theoretical framework of the paper is based on taxation and social responsibility theories that evaluate the impact of economic, financial and social decisions taken by firms,

Ftima David; Isabel Gallego

2009-01-01

271

Corporate identity and corporate image revisited - A semiotic perspective  

Microsoft Academic Search

Asserts that the marketing discipline has been quite instrumental in securing and maintaining both practical and theoretical attention to the issues of identity and image in contemporary organisations. Discusses and critiques much of the discourse of corporate identity and image management. This is accomplished through a semiotic exercise in which prevailing perspectives and assumptions with respect to corporate identity and

Lars Thger Christensen; Sren Askegaard

2001-01-01

272

Expanding radio astronomy in Africa  

NASA Astrophysics Data System (ADS)

The Square Kilometre Array (SKA) Organisation announced in May 2012 that its members had agreed on a dual site solution for the SKA [1]. South Africa's bid for hosting the SKA has caused a ramp up of radio astronomy in Africa. To develop technology towards the SKA, the South African SKA Project (SKA SA) built a protoype radio telescope in 2007, followed in 2010 the seven antenna Karoo Array Telescope (KAT-7). Next is the 64 antenna MeerKAT, which will merge into SKA Phase 1 in Africa. As SKA Phase 2 is intended to add a high resolution capability with baselines out to 3000 km, the SKA SA brought in partner countries in Africa to host outstations. South Africa has been working with the partners to build capacity to operate the SKA and to benefit from it. The SA Department of Science and Technology (DST) developed a proposal to establish radio telescopes in the partner countries to provide hands-on learning and a capability for Very Long Baseline Interferometry (VLBI) research. Redundant 30 m class satellite antennas are being incorporated in this project.

Gaylard, M. J.

2013-04-01

273

Exploring the Uranian satellites  

NASA Technical Reports Server (NTRS)

Data on the Uranian satellites from the January 25, 1986 flyby of Voyager 2 are presented. Ten new satellites were discovered by Voyager 2; the features and orbits of these ten satellites are examined. The main geological characteristics for Oberon, Umbriel, Titania, Ariel, and Miranda discovered in the Voyager 2 images are described. Possible relationships between the Uranian satellites and Jovian and Saturnian satellites are being researched.

Brown, Robert Hamilton

1986-01-01

274

Outer planet satellites  

SciTech Connect

Recent findings on the outer-planet satellites are presented, with special consideration given to data on the rheologic properties of ice on icy satellites, the satellite surfaces and exogenic processes, cratering on dead cratered satellites, volcanism, and the interiors of outer-planet satellites. Particular attention is given to the state of Titan's surface and the properties of Triton, Pluto, and Charon. 210 refs.

Schenk, P.M. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

275

Radio astronomy  

NASA Technical Reports Server (NTRS)

A K-band reflected-wave ruby maser was used on the 64-meter (DSS-43) antenna at the Tidbinbilla Tracking Station, near Canberra, Australia. Spectral line observations were carried out near 22 GHz for water vapor sources and near 24 GHz for ammonia sources. The water vapor observations were made in the direction of known southern OH and H2O maser sources. All of the previously detected water line sources examined were detected. In addition, two new water vapor maser sources were discovered, G301.1+1.1and G308.9+0.1. The spectrum of G301.0+1.1 is presented six ammonia sources were found: G291.3-0.7, G305.4+0.2, G322.2+0.6, G327.3-0.5, G333.6-0.2, and G268.4-0.8. Spectra of two of these sources, G291.3-0.7 (RCW 57) and G305.4+0.2, are presented. Both show clearly the presence of the quadrupole splitting satellite lines that will allow the determination of NH3 optical depths in these clouds.

Shaffer, R. D.; Mccluskey, J. T.; Gulkis, S.; Klein, M.; Kuiper, T.

1981-01-01

276

A Deep Space Network Portable Radio Science Receiver  

NASA Technical Reports Server (NTRS)

The Radio Science Receiver (RSR) is an open-loop receiver installed in NASA s Deep Space Network (DSN), which digitally filters and records intermediate-frequency (IF) analog signals. The RSR is an important tool for the Cassini Project, which uses it to measure perturbations of the radio-frequency wave as it travels between the spacecraft and the ground stations, allowing highly detailed study of the composition of the rings, atmosphere, and surface of Saturn and its satellites.

Jongeling, Andre P.; Sigman, Elliott H.; Chandra, Kumar; Trinh, Joseph T.; Navarro, Robert; Rogstad, Stephen P.; Goodhart, Charles E.; Proctor, Robert C.; Finley, Susan G.; White, Leslie A.

2009-01-01

277

The Earth as a Radio Source: Terrestrial Kilometric Radiation  

Microsoft Academic Search

Radio wave experiments on the Imp 6 and 8 satellites have shown that the earth emits very intense electromagnetic radiation in the frequency range of about 50-500 kHz. At peak intensity the total power emitted in this frequency range is about l09 W. The earth is therefore a very intense planetary radio source, with a total power output comparable to

Donald A. Gurnett

1974-01-01

278

Project Leader : Kenji Esaki (Toyota Motor Corporation)  

E-print Network

Project Leader : Kenji Esaki (Toyota Motor Corporation) Research / Toyota City / National Institute of Advanced Industrial Science and Technology / Institute of Physical and Chemical Research / Asahi Glass Co., Ltd. / DENSO Corporation / Toshiba Corporation / Toyota Motor

Takahashi, Ryo

279

27 CFR 31.123 - New corporation.  

...Firearms 1 2014-04-01 2014-04-01 false New corporation. 31.123 Section 31.123 Alcohol...Information Changes Requiring Registration As A New Business 31.123 New corporation. Where a new corporation is...

2014-04-01

280

27 CFR 31.123 - New corporation.  

Code of Federal Regulations, 2011 CFR

...Firearms 1 2011-04-01 2011-04-01 false New corporation. 31.123 Section 31.123 Alcohol...Information Changes Requiring Registration As A New Business 31.123 New corporation. Where a new corporation is...

2011-04-01

281

27 CFR 31.123 - New corporation.  

Code of Federal Regulations, 2010 CFR

...Firearms 1 2010-04-01 2010-04-01 false New corporation. 31.123 Section 31.123 Alcohol...Information Changes Requiring Registration As A New Business 31.123 New corporation. Where a new corporation is...

2010-04-01

282

Radio Science Concepts and Approaches for Jupiter Icy Moons Orbiter  

NASA Technical Reports Server (NTRS)

Radio Science experiments have been conducted on most deep space missions leading to numerous scientific discoveries. A set of concepts and approaches are proposed for the Jupiter Icy Moons Orbiter (JIMO) to apply Radio Science tools to investigate the interior structures of the Galilean Satellites and address key questions on their thermal and dynamical evolution. Measurements are identified that utilize the spacecraft's telecommunication system. Additional instruments can augment these measurements in order to leverage observational synergies. Experiments are also offered for the purpose of investigating the atmospheres and surfaces of the satellites.

Anderson, J. D.; Asmar, S. W.; Castillo, J. C.; Folkner, W. M.; Konopliv, A. S.; Marouf, E. A.; Rappaport, N. J.; Schubert, G.; Spilker, T. R.; Tyler, G. L.

2003-01-01

283

The Global Corporate Governance Forum  

Microsoft Academic Search

The Global Corporate Governance Forum (GCGF) is a multidonor trust fund founded by the World Bank Group and the Organization for Economic Co-operation and Development (OECD) to promote global, regional, and local initiatives that aim improving the institutional framework and practices of corporate governance. \\

Ross Levine

284

Corporal Punishment in the Schools.  

ERIC Educational Resources Information Center

A continuing dichotomy in public opinion concerning the use of corporal punishment in Canadian schools provided the impetus for this paper, which includes a review of the relevant literature. Morality issues surrounding corporal punishment are discussed and public opinion data are exerpted from the Provincial Review of School Disciplinary Policy

Review and Evaluation Bulletins, 1981

1981-01-01

285

Corporate Social Responsibility in China  

Microsoft Academic Search

Current understandings of corporate social responsibility practices and attitudes have been mainly driven by 'western-centric' data and philosophical approaches. China is undergoing a vast economic boom, and research attention is turning to the practices and attitudes of Chinese firms in regard to corporate social responsibility. The current paper used a qualitative multi-case method to examine CSR motivations, policies, and practices

Michael Ewing; Lydia Windisch

286

Market distortions and corporate governance  

Microsoft Academic Search

This paper studies corporate governance when a firm operates in imperfect markets. We derive firms' decisions from utility maximisation by individuals. This reduces the usual monopoly distortion. Corporate governance can effect the equilibrium in the product (or input) markets. This enables us to endogenise the objective function of the firm. If the firm cannot commit not to change its constitution,

David Kelsey; Frank Milne

2005-01-01

287

A Survey of Corporate Governance  

Microsoft Academic Search

This article surveys research on corporate governance, with special attention to the importance of legal protection of investors and of ownership concentration in corpo- rate governance systems around the world. CORPORATE GOVERNANCE DEALS WITH the ways in which suppliers of finance to

ANDREI SHLEIFER; ROBERT W. VISHNY

1988-01-01

288

Corporal Punishment and Child Adjustment  

ERIC Educational Resources Information Center

The association between corporal punishment and children's emotional and behavioral functioning was studied in a sample of 98 non-referred children with a mean age of 12.35 (SD=1.72) recruited from two school systems in the southeastern United States. Children were divided into those who had experienced no corporal punishment over approximately a

Aucoin, Katherine J.; Frick, Paul J.; Bodin, S. Doug

2006-01-01

289

Corporate Governance in Financial Institutions  

Microsoft Academic Search

On 29th - 30th March 2007, SUERF and the Central Bank of Cyprus jointly organized a Seminar: Corporate Governance in Financial Institutions. The papers in the present publication are based on a sample of the presentations at the Seminar. Together, the papers illuminate a number of key issues in corporate governance in a variety of financial firms. In the first

Spyros G. Stavrinakis; Christian Harm; David T. Llewellyn; Bridget Gandy; Peter Shaw; Peter Tebbutt; Mark Young

290

The Banning of Corporal Punishment.  

ERIC Educational Resources Information Center

Presents the 1985 resolution of the Association for Childhood Education International (ACEI) for participation in the interdisciplinary effort to ban corporal punishment. Discusses distinctions between discipline and child abuse. Reports medical and psychological effects of physical punishment, and relationships between school corporal punishment

Cryan, John R.

1995-01-01

291

University Corporate Cards 1. Introduction  

E-print Network

University Corporate Cards 1. Introduction The University may issues credit cards to staff members who travel frequently or who incur high levels of non-procurement expenditure. The cards are only of equipment. 2. Applying for a University Corporate Card Application forms for a credit card must be completed

Levi, Ran

292

Corporate Card Program Cardmember Application  

E-print Network

Corporate Card Program Cardmember Application Club Rewards® /Club Cash® Enrollment Individual Billing *Application cannot be processed without this required information. DINERS CLUB® CORPORATE CARD Rewards points on all eligible transactions charged to my Diners Club Card. I understand that a yearly fee

Haykin, Simon

293

Corporate Fraud, Governance and Auditing  

Microsoft Academic Search

We analyze corporate fraud in a model in which managers have superior information but are biased against liquidation, because of their private benefits from empire building. This may induce them to misreport information and even bribe auditors when liquidation would be value-increasing. To curb fraud, shareholders optimally choose auditing quality and the performance sensitivity of managerial pay, taking external corporate

Giovanni Immordino; Marco Pagano

2008-01-01

294

Corporate Ownership Around the World  

Microsoft Academic Search

We use data on ownership structures of large corporations in 27 wealthy economies to identify the ultimate controlling shareholders of these firms. We find that, except in economies with very good shareholder protection, relatively few of these firms are widely held, in contrast to Berle and Means's image of ownership of the modern corporation. Rather, these firms are typically controlled

Rafael La Porta; Florencio Lopez-De-Silanes; Andrei Shleifer

1999-01-01

295

FORTE observations of lightning radio-frequency signatures: Capabilities and basic results  

Microsoft Academic Search

The FORTE satellite, launched on August 29, 1997, carries both radio-frequency-receiver and optical (imaging and photometric) payloads for the study of lightning. The radio-frequency (RF) data for the first 7 months of operation are described, both to illustrate the satellite{close_quote}s capabilities and to explain the basic statistical findings so far. FORTE{close_quote}s multichannel RF trigger system represents a significant advance in

Abram R. Jacobson; Stephen O. Knox; Robert Franz; Donald C. Enemark

1999-01-01

296

Satellite-to-ground radiowave propagation - Theory, practice and system impact at frequencies above 1 GHz  

Microsoft Academic Search

The effects of the earth atmosphere on radio waves traveling from GEO satellites to the ground are examined in a text which includes both introductory material suitable for undergraduate engineering students and detailed information and references for practicing radio engineers. Chapters are devoted to ionospheric effects; clean-air effects; attenuation effects; depolarization effects; terrain, multipath, and other particulate effects; and the

Jeremy E. Allnutt

1989-01-01

297

Rural Community Assistance Corporation  

NSDL National Science Digital Library

Founded in 1978, the Rural Community Assistance Corporation (RCAC) is dedicated ??to assisting rural communities in achieving their goals and visions by providing training, technical assistance and access to resources.? Their work is primarily focused on work in the 13 Western states and for communities with populations under 50,000. The homepage is quite inviting, and allows users to peruse a list of upcoming events and support activities sponsored by the RCAC or other like-minded organizations. Persons seeking assistance or working on behalf of such communities will appreciate information from the homepage on such programs as housing, financing, and rural infrastructure development initiatives. The publications area of the site is quite strong, especially considering that visitors can study over ten newsletters here, including Alaska Anew, which details specifically with the search for finding solutions to the solid waste problem in Alaska.

298

The Solar Development Corporation  

SciTech Connect

This paper describes a proposed stand alone company, the Solar Development Corporation (SDC), to be a business development and financing entity for photovoltaic operations with the potential to be commercially sustainable. SDC will have a fully integrated policy advocacy link to the World Bank. SDC will define target countries where the potential exists for significant early market expansion. In those countries it will provide: market and business development services that will accelerate the growth of private firms and deepen the penetration of Solar Home Systems (SHS) and other rural PV applications in the market; and access to pre-commercial and parallel financing for private firms to (1) expand their capability in PV distribution businesses, and (2) strengthen their ability to provide credit to end users. SDC itself will not engage in direct financing of the final consumer. It is intended that as far as possible SDC`s finance will be provided in parallel with financing from Financial Intermediaries.

Singer, C.E.

1997-12-01

299

Energy Efficient Radio Resource  

E-print Network

Energy Efficient Radio Resource Management in a Coordinated Multi-Cell Distributed Antenna System Omer HALILOGLU Introduction System Model Performance Evaluation Conclusion References Energy Efficient Hacettepe University 5 September 2014 Omer HALILOGLU (Hacettepe University) Energy Efficient Radio Resource

Yanikomeroglu, Halim

300

Resonance and Radio  

ERIC Educational Resources Information Center

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.)

Starrett, Malin J.

2008-01-01

301

Tracking Data Relay Satellite System (TDRSS) VHF propagation study  

NASA Technical Reports Server (NTRS)

A study performed to investigate the use of the Bent Ionospheric Model in computing corrections to the range and range rate measurements of the TDRSS satellites is documented. Several orbital configurations between the two satellites are discussed as to their effects on total electron content along the radio path between the satellites. Problem areas in the accurate computation of total electron content and range rate corrections are also discussed. The Bent Ionospheric Model gives the electron density versus height profile as a function of latitude, longitude, height, time, season, and solar flux.

Schleicher, L. A. H.; Llewellyn, S. K.; Bent, R. B.

1973-01-01

302

Quad-Tree Visual-Calculus Analysis of Satellite Coverage  

NASA Technical Reports Server (NTRS)

An improved method of analysis of coverage of areas of the Earth by a constellation of radio-communication or scientific-observation satellites has been developed. This method is intended to supplant an older method in which the global-coverage-analysis problem is solved from a ground-to-satellite perspective. The present method provides for rapid and efficient analysis. This method is derived from a satellite-to-ground perspective and involves a unique combination of two techniques for multiresolution representation of map features on the surface of a sphere.

Lo, Martin W.; Hockney, George; Kwan, Bruce

2003-01-01

303

Developments in land mobile satellite service in Europe  

NASA Technical Reports Server (NTRS)

The evolution of land mobile radio has reached a stage to benefit from satellite communications. The provision of a service on a pan-European basis makes the use of satellites a viable proposition. The paper describes the European position on both system and space segment aspects of the land mobile satellite service. Also, some of the functions of the European institutions, such as the European Telecommunications Standards Institute (ETSI), the Conference of European Postal and Telecommunications Administrations (CEPT), and the Commission of European Communities (CEC), in establishing these services are identified.

Jayasuriya, D. A. R.

1990-01-01

304

Radio Diaries on National Public Radio (NPR)  

NSDL National Science Digital Library

Radio Diaries is a nonprofit radio production company which looks "to find extraordinary stories in ordinary places, to create original and moving first-person documentaries - true radio verite - from voices that are rarely heard." And that it does. Radio Diaries staff train all kinds of people -- from teenagers to the elderly -- to become reporters. These fledgling reporters create tapes about their area of interest, tell their stories, and send their product back to Radio Diaries. A collaborative editing process then ensues, and the end product is aired as part of National Public Radio's All Things Considered. The Radio Diaries site brings together an amazing range of recorded stories divided into adult and teen areas. Two examples of diaries on the site include a piece by a teenager from New York City with Tourette's Syndrome as well as the story of the last two known remaining Civil War widows whose husbands fought on opposing sides of the war. Users can listen to the recordings using RealPlayer, or they can read transcripts; other materials are occasionally included too. The site encourages users to send in their own story ideas and will provide even more support for creative ventures with their Handbook for Teen Reporters (available in January of 2000). The site also has a store section where tapes of various radio diaries are for sale.

305

An African VLBI network of radio telescopes  

E-print Network

The advent of international wideband communication by optical fibre has produced a revolution in communications and the use of the internet. Many African countries are now connected to undersea fibre linking them to other African countries and to other continents. Previously international communication was by microwave links through geostationary satellites. These are becoming redundant in some countries as optical fibre takes over, as this provides 1000 times the bandwidth of the satellite links. In the 1970's and 1980's some two dozen large (30 m diameter class) antennas were built in various African countries to provide the satellite links. Twenty six are currently known in 19 countries. As these antennas become redundant, the possibility exists to convert them for radio astronomy at a cost of roughly one tenth that of a new antenna of similar size. HartRAO, SKA Africa and the South African Department of Science and Technology (DST) have started exploring this possibility with some of the African countries...

Gaylard, M J; Combrinck, L; Booth, R S; Buchner, S J; Fanaroff, B L; MacLeod, G C; Nicolson, G D; Quick, J F H; Stronkhorst, P; Venkatasubramani, T L

2014-01-01

306

Hearing America: A Century of Music on the Radio  

NSDL National Science Digital Library

As one of the lyrics by the Brothers Gershwin goes: "They told Marconi/wireless was a phony." Of course, the wireless world of the radio and its galaxy of musical choices has changed from the transmission of mere Morse code in its early decades to today's overwhelming choices afforded by different satellite radio companies. This recent documentary by the American RadioWorks program explores the history of American radio, and how it has been the site of many a cultural battle over the past ten decades. This site allows users to listen to the entire program, and it also includes a number of nice web features. These include maps that chart the growth of AM and FM stations from 1922 through 2006 and some engaging essays, such as "Radio Fights Jim Crow" and "Sex, Race and Rock & Roll".

307

International Ultraviolet Explorer (IUE) satellite mission analysis  

NASA Technical Reports Server (NTRS)

The results are presented of the mission analysis performed by Computer Sciences Corporation (CSC) in support of the International Ultraviolet Explorer (IUE) satellite. The launch window is open for three separate periods (for a total time of 7 months) during the year extending from July 20, 1977, to July 20, 1978. The synchronous orbit shadow constraint limits the launch window to approximately 88 minutes per day. Apogee boost motor fuel was computed to be 455 pounds (206 kilograms) and on-station weight was 931 pounds (422 kilograms). The target orbit is elliptical synchronous, with eccentricity 0.272 and 24 hour period.

Cook, R. A.; Griffin, J. H.

1975-01-01

308

DETECTION AND BLANKING OF GSM INTERFERENCE IN RADIO-ASTRONOMICAL OBSERVATIONS  

E-print Network

DETECTION AND BLANKING OF GSM INTERFERENCE IN RADIO-ASTRONOMICAL OBSERVATIONS Amir Leshem, Alle, satellite and broad- cast services. In particular, the GSM band is a highly satu- rated domain, full to radio astronomy, and the GSM sys- tem which became ubiquitous and thus prevents observation in its band

van der Veen, Alle-Jan

309

The Effect of Radio-Collar Weight on Survival of Migratory Caribou  

E-print Network

. We compared the survival of 269 randomly selected adult migratory caribou (Rangifer tarandus) fitted, radio transmitter weight, Rangifer tarandus, satellite/VHF collars, survival, Ungava caribou. Radio such as greater snow goose (Anser caerulescens atlanticus) or caribou (Rangifer tarandus) that travel hundreds

Festa-Bianchet, Marco

310

Potential Spacecraft-to-Spacecraft Radio Observations with EJSM: Wave of the Future? (Invited)  

Microsoft Academic Search

Future active radio observations of planetary and satellite atmospheres and surfaces could significantly benefit form the presence of two or more spacecraft in orbit around a target object. Traditionally, radio occultation and bistatic surface scattering experiments have been conducted using a single spacecraft operating in the Downlink (DL) configuration, with the spacecraft transmitting and at least one Earth-based station receiving.

E. A. Marouf; P. Tortora; S. W. Asmar; W. M. Folkner; D. Hinson; L. Iess; I. R. Linscott; R. D. Lorenz; I. C. Mueller-Wodarg

2010-01-01

311

Stereo Measurements from Satellites  

NASA Technical Reports Server (NTRS)

The papers in this presentation include: 1) 'Stereographic Observations from Geosynchronous Satellites: An Important New Tool for the Atmospheric Sciences'; 2) 'Thunderstorm Cloud Top Ascent Rates Determined from Stereoscopic Satellite Observations'; 3) 'Artificial Stereo Presentation of Meteorological Data Fields'.

Adler, R.

1982-01-01

312

Hurricane Katrina Satellite Imagery  

NSDL National Science Digital Library

This page provides access to a good number of satellite images of Hurricane Katrina taken by polar orbiting and geostationary satellites operated by NOAA. High resolution images are available on the site.

National Environmental Satellite, Data, and Information Service

313

PASCO CORPORATION 1953-2010 Corporate Profile & SASKE Project  

E-print Network

- Internet / Intranet/WEB - Integrated GIS / CorporateGIS - Spatial Data Warehouse etc. Systems Development - Systems Design - Prototype Development - Application Development etc. Software, data - Integrated GIS Design of Underground Structures Erosion Planning & Design Water Supply and Drainage Design Waste

314

25 CFR 227.6 - Corporations and corporate information.  

Code of Federal Regulations, 2011 CFR

...227.6 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF CERTAIN LANDS IN WIND RIVER INDIAN RESERVATION, WYOMING, FOR OIL AND GAS MINING How to Acquire Leases 227.6 Corporations and...

2011-04-01

315

25 CFR 227.6 - Corporations and corporate information.  

Code of Federal Regulations, 2013 CFR

...227.6 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF CERTAIN LANDS IN WIND RIVER INDIAN RESERVATION, WYOMING, FOR OIL AND GAS MINING How to Acquire Leases 227.6 Corporations and...

2013-04-01

316

25 CFR 227.6 - Corporations and corporate information.  

Code of Federal Regulations, 2012 CFR

...227.6 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF CERTAIN LANDS IN WIND RIVER INDIAN RESERVATION, WYOMING, FOR OIL AND GAS MINING How to Acquire Leases 227.6 Corporations and...

2012-04-01

317

The nexus between ethical corporate marketing, ethical corporate identity and corporate social responsibility : An internal organisational perspective  

Microsoft Academic Search

Purpose The commentary aims to consider the nexus between corporate marketing, ethical corporate marketing, ethical corporate identity and corporate social responsibility. It seeks to take an explicit internal organisational perspective. It also aims to identify future research avenues. Design\\/methodology\\/approach The commentary explains the relevance of the previous interlinking concepts with a discussion based on a review of past

Shaun M. Powell

2011-01-01

318

Radio Detection of Radio-Quiet Galaxies  

E-print Network

We investigate the radio emission of ~185,000 quiescent (optically unclassifiable) galaxies selected from the Sloan Digital Sky Survey (SDSS). By median-stacking FIRST cutouts centered on the optically-selected sources, we are able to reach flux densities down to the 10s of microJy. The quiescent galaxy sample is composed of two subgroups inhabiting vastly different regimes: those targeted for the SDSS MAIN Galaxy Sample (~55%), and those targeted for the Luminous Red Galaxy (LRG) sample (~45%). To investigate the star-formation rates (SFRs) of these quiescent galaxies, we calibrate a radio-SFR conversion using a third sample of star-forming galaxies. Comparing this SFR-indicator with indicators in the optical and UV, we derive conflicting SFR estimates for the MAIN sample quiescent galaxies. These radio-derived SFRs intersect those calculated using the 4000-Angstrom break (D4000) around an SFR of 1 Msun/yr and agree to within a factor of 3 over the range of SFRs. However, we find that the radio-derived SFRs are too high relative to the SFRs estimated for similar populations of galaxies using analysis of UV emission, implying either contamination of the radio by Active Galactic Nuclei (AGN) or incomplete dust modeling. If AGN activity is dominant in these galaxies, then a relation between AGN radio luminosity and galaxy mass is required to explain the observed trends. For the LRGs, on the other hand, we find the radio luminosity to be independent of SFR as derived from D4000, indicating an AGN component dominates their radio emission. AGN-based radio emission often implies the existence of radio jets, providing evidence of a mechanism for low-level feedback in these quiescent LRGs. (Abridged)

J. A. Hodge; R. H. Becker; R. L. White; W. H. de Vries

2008-06-25

319

Ionospheric effects upon a satellite navigation system at Mars Michael Mendillo,1  

E-print Network

Ionospheric effects upon a satellite navigation system at Mars Michael Mendillo,1 Xiaoqing Pi,2 satellites at Mars. Using recent results from the radio science experiment on board the Mars Global Surveyor (MGS) spacecraft and a photochemical model of Mars' ionosphere, we study the total electron content

Mendillo, Michael

320

A Guide to the Literature on Application of Communications Satellites to Educational Development.  

ERIC Educational Resources Information Center

Because of the ability of communications satellites to distribute electronic information (radio, television, digital computer data) over wide areas with potentially attractive costs, considerable interest has been shown in using satellite technology to enhance educational programs, both in the United States and in other countries. In view of these

Morgan, Robert P.; Singh, Jai P.

321

Galileo radio science investigations  

Microsoft Academic Search

The radio science investigations planned for Galileo's 6-year flight to and 2-year orbit of Jupiter use as their instrument the dual-frequency radio system on the spacecraft operating in conjunction with various US and German tracking stations on Earth. The planned radio propagation experiments are based on measurements of absolute and differential propagation time delay, differential phase delay, Doppler shift, signal

H. T. Howard; V. R. Eshleman; D. P. Hinson; A. J. Kliore; G. F. Lindal; R. Woo; M. K. Bird; H. Volland; P. Edenhoffer; M. Paetzold; H. Porsche

1992-01-01

322

The software radio architecture  

Microsoft Academic Search

As communications technology continues its rapid transition from analog to digital, more functions of contemporary radio systems are implemented in software, leading toward the software radio. This article provides a tutorial review of software radio architectures and technology, highlighting benefits, pitfalls, and lessons learned. This includes a closer look at the canonical functional partitioning of channel coding into antenna, RF,

J. Mitola

1995-01-01

323

Radio Wave Propagation  

Microsoft Academic Search

Electromagnetic radio waves traveling within earth's atmosphere are called terrestrial waves, and communications between two or more points on earth is called terrestrial radio communications. Terrestrial waves are influenced by the atmosphere and earth itself. In terrestrial radio communications, waves can be propagated in several ways, depending on the type of system and the environment. Electromagnetic waves also travel in

S. Venkatesh

2007-01-01

324

Radio search for exoplanets  

E-print Network

Radio search for exoplanets Philippe Zarka LESIA, Observatoire de Paris/CNRS, Meudon philippe.zarka) [Zarka et al., 1997; Zarka, , 2004, 2007] #12;· Low-frequency radio observations of exoplanets;Aurorae #12;Aurorae #12;Magnetospheric (auroral) radio emissions [Zarka, 1998] #12;Properties of auroral

Demoulin, Pascal

325

Introduction Big Radio Data  

E-print Network

Introduction VLBI Pulsars Summary Big Radio Data Ue-Li Pen CITA, UofT, CIFAR July 3, 2014U. Pen Big Radio Data #12;Introduction VLBI Pulsars Summary Overview History VLBI Processing Future U. Pen Big signal processing U. Pen Big Radio Data #12;Introduction VLBI Pulsars Summary VLBI Current experiments

Prodiæ, Aleksandar

326

Extragalactic Radio Sources  

ERIC Educational Resources Information Center

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

Kellerman, Kenneth I.

1973-01-01

327

Estimating lightning current moment waveforms from satellite optical measurements  

E-print Network

Estimating lightning current moment waveforms from satellite optical measurements Toru Adachi,1 and Duke magnetometer observed clear optical and radio signatures of 12 sprite- producing lightning events to remotely measure lightning current moment, which is critical for understanding the production of sprites

California at Berkeley, University of

328

Frequency allocation problem in a SDMA satellite communication system  

E-print Network

Frequency allocation problem in a SDMA satellite communication system Laurent Houssina SDMA (Spatial Division Multiple Access) is a principle of radio resource sharing that relies on the division of the space dimension into separated communication channels. SDMA basically relies on adaptive

Boyer, Edmond

329

NASA-GSFC ionospheric corrections to satellite tracking data  

NASA Technical Reports Server (NTRS)

An overview is presented of the development, verification, and recent implementation of the NASA-GSFC ionospheric model for satellite tracking data corrections. This model was incorporated into the Goddard Trajectory Determination System which is providing continuous trajectory computation support for the lunar orbiting Radio Astronomy Explorer-B launched on 10 June 1973.

Schmid, P. E.; Bent, R. B.; Llewellyn, S. K.; Nesterczuk, G.; Rangaswamy, S.

1971-01-01

330

Radio occultation experiments with INAF-IRA radiotelescopes.  

NASA Astrophysics Data System (ADS)

The Radio Occultation research program performed at the Medicina and Noto Radioastronomical Stations of the Istituto Nazionale di Astrofisica (INAF) - Istituto di Radioastronomia (IRA) includes observations of spacecraft by satellite and satellite by satellite events. The Lunar Radio Occultation (LRO) part of the program consists in collecting data of the lunar Total Electron Content (TEC), at different limb longitudes and at different time, in order to study long term variation of the Moon's ionosphere. The LRO program started at Medicina in September 2006 with the observation of the European probe SMART-1 during its impact on the lunar soil. It proceeded in 2007 with the observation of the lunar occultations of Saturn and Venus, and with the observation of Mars in 2008. On this occasion the probes Cassini, Venus Express, Mars Express, Mars Reconaissance Orbiter and Mars Odissey were respectively occulted by the moon. On Dec 1st 2008 a Venus lunar occultation occurred. On that occasion we performed the first Italian-VLBI (I-VLBI) tracking experiment by detecting the carrier signals coming from the Venus Express (VEX) spacecraft with both the IRA radiotelescopes together with the Matera antenna of the Italian Space Agency. The second part of the radio occultation program includes the observation of satellite by satellite occultation events, as well as mutual occultations of Jupiter satellites. These events are referred to as mutual phenomena (PHEMU). These observations are aimed to measure the radio flux variation during the occultation and to derive surface spatial characteristics such as Io's hot spots. In this work preliminary results of the Radio Occultation program will be presented.

Pluchino, S.; Schillir, F.; Salerno, E.; Pupillo, G.

331

Modern Technologies: Satellites  

NSDL National Science Digital Library

The world's increasing dependence on satellites was recently made clear when a PanAmSat communications satellite went down, disrupting communication and data transmission around the world. The eight resources in this week's In the News highlight satellites, and the many important roles they play in our lives. Today, satellites are used to convey a wealth of information, from communications to important scientific data.

Harris, Kathryn L.

1998-01-01

332

Corporate social responsibility disclosure and corporate governance in Malaysia  

Microsoft Academic Search

Using 743 Malaysian public listed companies, this study attempts to investigate the impact of corporate governance mechanism on corporate social responsibility (CSR) disclosure level and to examine the difference of CSR disclosure level in government-linked companies and non-government linked companies. Employing multivariate analysis, the study reveals that the presence of larger non-executive directors and a higher involvement of institutional shareholders,

Ying Zhee Lim; Mohammad Talha; Junaini Mohamed; Abdullah Sallehhuddin

2008-01-01

333

EUROPE'S GEOSTATIONARY METEOROLOGICAL SATELLITES  

E-print Network

METEOSAT EUROPE'S GEOSTATIONARY METEOROLOGICAL SATELLITES MONITORING WEATHER AND CLIMATE FROM SPACE, 6 July 2010 Paul de Valk Koninklijk nederlands Meteorologisch instituut (KnMi) "you need satellites for a country to have its own satellites so it is very beneficial to share costs in Europe, as we do through Eu

Stoffelen, Ad

334

IMAGE Satellite Scale Model  

NSDL National Science Digital Library

This is an activity about scale model building. Learners will use mathematics to determine the scale model size, construct a pattern, and build a paper scale model of the IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) satellite, the first satellite mission to image the Earth's magnetosphere. This is the second activity in the Solar Storms and You: Exploring Satellite Design educator guide.

335

Case study on complex sporadic E layers observed by GPS radio occultations  

NASA Astrophysics Data System (ADS)

The occurrence of sporadic E (Es) layers has been a hot scientific topic for a long time. The GNSS (global navigation satellite system)-based radio occultation (RO) has proven to be a powerful technique for detecting the global Es layers. In this paper, we focus on some cases of complex Es layers based on the RO data from multiple missions processed in UCAR/CDAAC (University Corporation for Atmospheric Research (UCAR) the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Data Analysis and Archive Center (CDAAC)). We first show some examples of multiple Es layers occurred in one RO event. Based on the evaluations between colocated simultaneous RO events and between RO and lidar observations, it could be concluded that some of these do manifest the multiple Es layer structures. We then show a case of the occurrence of Es in a broad region during a certain time interval. The result is then validated by independent ionosondes observations. It is possible to explain these complex Es structures using the popular wind shear theory. We could map the global Es occurrence routinely in the near future, given that more RO data will be available. Further statistical studies will enhance our understanding of the Es mechanism. The understanding of Es should benefit both Es-based long-distance communication and accurate neutral RO retrievals.

Yue, X.; Schreiner, W. S.; Zeng, Z.; Kuo, Y.-H.; Xue, X.

2015-01-01

336

Cognitive Radio will revolutionize American transportation  

SciTech Connect

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

None

2013-07-22

337

Cognitive Radio will revolutionize American transportation  

ScienceCinema

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

None

2013-12-06

338

A Political Economy Model of Corporate Governance  

Microsoft Academic Search

We develop a political economy model of how the corporate law rules governing publicly traded firms are determined. In our model, a corporate insiders' lobby com- petes for influence over politicians setting corporate law rules against an institutional investors' lobby that represents the interests of outside shareholders. We show that if the politicians who determine corporate law rules are influenced

Lucian Bebchuk; Zvika Neeman

339

Web Reimbursement Corporate Card Payments and Credits  

E-print Network

Web Reimbursement Corporate Card Payments and Credits 7/19/2012 For Harvard Business Use Only Page Reimbursement Corporate Card Payments and Credits 7/19/2012 For Harvard Business Use Only Page 2 Corporate Card of security policy. #12;Web Reimbursement Corporate Card Payments and Credits 7/19/2012 For Harvard Business

340

The role of corporations in ensuring biodiversity  

Microsoft Academic Search

Corporations own approximately 25% of all private land in the United States and, therefore, play an essential role in protecting biodiversity and maintaining natural habitats. The Wildlife Habitat Council (WHC) is a unique joint venture between conservation organizations and corporations to utilize corporate lands for ensuring biodiversity. The following case studies demonstrate how corporations have helped ensure healthy ecosystems and

Joyce M. Kelly; Michael R. Hodge

1996-01-01

341

Study on Corporate Hereditary Central Dogma  

Microsoft Academic Search

Based on analyzing the central dogma of biology, this paper raises hypothesis, using the analogism method to set up the corporate hereditary central dogma. It analyzes the differences between the Corporate hereditary central dogma and the central dogma of biology, which explains the significance of research on Corporate hereditary central dogma; it discusses the meanings of all factors of Corporate

Li Xianbai

2010-01-01

342

Local oscillator distribution using a geostationary satellite  

NASA Technical Reports Server (NTRS)

A satellite communication system suitable for distribution of local oscillator reference signals for a widely spaced microwave array has been developed and tested experimentally. The system uses a round-trip correction method of the satellite This experiment was carried out using Telstar-5, a commercial Ku-band geostationary satellite. For this initial experiment, both earth stations were located at the same site to facilitate direct comparison of the received signals. The local oscillator reference frequency was chosen to be 300MHz and was sent as the difference between two Ku-band tones. The residual error after applying the round trip correction has been measured to be better than 3psec for integration times ranging from 1 to 2000 seconds. For integration times greater then 500 seconds, the system outperforms a pair of hydrogen masers with the limitation believed to be ground-based equipment phase stability. The idea of distributing local oscillators using a geostationary satellite is not new; several researchers experimented with this technique in the eighties, but the achieved accuracy was 3 to 100 times worse than the present results. Since substantially and the performance of various components has improved. An important factor is the leasing of small amounts of satellite communication bandwidth. We lease three 100kHz bands at approximately one hundredth the cost of a full 36 MHz transponder. Further tests of the system using terminal separated by large distances and comparison tests with two hydrogen masers and radio interferometry is needed.

Bardin, Joseph; Weinreb, Sander; Bagri, Durga

2004-01-01

343

Corporate Security and Conflict Outcomes  

E-print Network

This dissertation investigates the effects of private security firms (PSFs) on conflict outcomes. PSFs are corporations that are publicly or individually owned that provide security services for hire. Security services include, but are not limited...

Tkach, Benjamin K

2013-10-21

344

Encycogov: Encyclopedia of Corporate Governance  

NSDL National Science Digital Library

Encyclopedia of Corporate Governance, or encycogov for short, is created and maintained by Henrik Mathiesen, a PhD candidate at the Department of International Economics and Management at the Copenhagen Business School. Content on the site is divided into two sections: Specific Topics and General Topics. Topics in both sections begin with a paragraph explaining the overarching definition of the principle, and link to a variety of tables, "exhibitions," and models that further illustrate the definition. For example, the Bankruptcy Systems section begins with the definition and is followed up by two tables: "Effects of bankruptcy systems on corporate performance and other kinds of institutions of relevance for corporate governance" and "International corporate governance- Tentative characterizations of legal and empirical state of large firm bankruptcy systems in various countries as of 1980-95: 1) Developing countries. 2)Germany. 3) Japan. 4) Anglo-American countries. 5) Denmark." Also included on the site are references and site users information.

2010-01-05

345

Developing Corporate Author Search Keys.  

ERIC Educational Resources Information Center

Describes a systematic approach to the design of fixed-length, derived, truncated search keys for corporate author records; and a statistical method for predicting the performance of search keys for files of arbitrary size. (VT)

Bourg, James W.; And Others

1978-01-01

346

Campuses Weld the Corporate Link.  

ERIC Educational Resources Information Center

A 1984 survey by American Council on Education, Campus Trends, offers evidence of the extent of academe's involvement in corporate-college collaborative activities. Links including assisting students, supporting research, training employees, and joint programs are discussed. (MLW)

El-Khawas, Elaine

1985-01-01

347

Regional soil moisture retrievals and simulations from assimilation of satellite microwave brightness temperature observations  

Microsoft Academic Search

Low-frequency microwave satellite observations are sensitive to land surface soil moisture (SM). Using satellite microwave\\u000a brightness temperature observations to improve SM simulations of numerical weather, climate and hydrological predictions is\\u000a one of the most active research areas of the geoscience community. In this paper, Yan and Jins (J Radio Sci 19(4):386392,\\u000a 2004) theory on the relationship between satellite microwave remote

Xiaokang ShiJun; Jun Wen; Lei Wang; Tangtang Zhang; Hui Tian; Xin Wang; Rong Liu; Jinghui Zhang

2010-01-01

348

GPS radio occultation with GRACE: Atmospheric profiling utilizing the zero difference technique  

Microsoft Academic Search

Radio occultation events recorded on 2829 July 2004 by a GPS receiver aboard the GRACE-B satellite are analyzed. The stability of the receiver clock allows for the derivation of excess phase profiles using a zero difference technique, rendering the calibration procedure with concurrent observations of a reference GPS satellite obsolete. 101 refractivity profiles obtained by zero differencing and 96 profiles

G. Beyerle; T. Schmidt; G. Michalak; S. Heise; J. Wickert; C. Reigber

2005-01-01

349

Corporate Governance and Equity Prices  

Microsoft Academic Search

Corporate-governance provisions related to takeover defenses and shareholder rights vary substantially across firms. In this paper, we use the incidence of 24 different provisions to build a 'Governance Index' for about 1,500 firms per year, and then we study the relationship between this index and several forward-looking performance measures during the 1990s. We find a striking relationship between corporate governance

Paul A. Gompers; Joy L. Ishii; Andrew Metrick

2001-01-01

350

Corporate Yoga and Its Implications  

Microsoft Academic Search

\\u000a Yoga is being practiced as a complete means of total health and human excellence for time immemorial. So attraction towards\\u000a Yoga has been highly increased in corporate world, especially in developed countries. Merely US invests $ 5.7 billion dollar\\u000a per year for yoga classes and products [1]. Large corporations of the world like MICROSOFT, IBM, HBO, The White House, New

Rudra Bhandari; Balkrishna Acharya; V. K. Katiyar

351

Tax aspects of collapsible corporations  

E-print Network

of Collapsible Corporation. . . . , Principally "Vi ith A View To" Collapsible Property. . . Substantial Part . Presumption in Certain Cases. . . . . . . . . . 21 22 23 24 29 34 40 III. LIMITATIONS TO THE COLLAPSIBLE PROVISION . . Stock Ownership... in the liquidation. 1 The shareholder receiving cash or other property in complete liquidation of a corporation treats the cash and fair market value of the property as ordinary income to the extent that it represents the dis- tribution of accumulated earnings...

Lehmann, Herman August

1960-01-01

352

BASF Corporate Energy Management Process  

E-print Network

Health & Beauty Packaging Key customer industries BASF North America 6 ESL-IE-14-05-30 Proceedings of the Thrity-Sixth Industrial Energy Technology Conference New Orleans, LA. May 20-23, 2014 7Management Commitment Assess Performance & Set Goals... 1999 Corporate Energy Management Program 1999 Corporate Motor Management Guideline 2000 Geismar Cogeneration AOG Fuel Utilization 2001 Freeport Cogeneration Project 2002 Portsmouth Site Energy Team 2003 Freeport ISBL Energy Audits 2004 Energy...

Geiger, T.

2014-01-01

353

The ideal satellite pharmacy.  

PubMed

The pharmacy service at the Seattle Veterans Administration Medical Center moved into a replacement facility in September 1986. A description of the present medical center and the satellite pharmacy is presented. The ideal satellite pharmacy for this medical center is then described. The satellite is discussed with respect to the satellite door, transportation systems (i.e., dumbwaiter, pneumatic tubes), communication systems (i.e., Omnifax, intercom, typewriter, telephone, computer), equipment (i.e., IV hood, refrigerator, shelving), stock, and space. Because each medical center has specific needs and equipment available, the information presented should be used as a guide when designing a satellite pharmacy. PMID:10280299

Suzuki, N T

1987-02-01

354

Satellite system survivability  

SciTech Connect

Present U.S. military capability relies heavily on Earth satellites to maintain connectivity. The essential nature of these satellite systems has made them tempting targets to nuclear attack in wartime. The author reviews U.S. history in high-altitude nuclear device testing and nuclear effects testing on satellites, events in which he directly participated. Physics of the production of nuclear enhanced high-altitude electron belts are reviewed. The author discusses primary effects of the enhanced environment on satellite components. A glimpse into future satellite hardening reveals measures against developing directed energy weapons.

Shelton, F.H.

1983-01-01

355

Radio Loud and Radio Quiet Quasars  

NASA Astrophysics Data System (ADS)

It has been half a century since the population of radio quiet quasars has been recognized. Although all quasars are thought to contain a supper massive black hole which powers their extraordinary optical luminosity, it is still not clear why only a small fraction of optically selected quasars are strong radio sources. Using 5 GHz VLA observations, we compare the radio and optical properties of 179 quasars selected from the SDSS with absolute magnitude brighter than -23 and contained within a volume limited sample defined by redshifts between 0.2 and 0.3.

Kellermann, Kenneth I.; Kimball, Amy E.; Condon, James J.; Perley, Richard A.; Ivezic, Zeljko

2015-01-01

356

Survey: National Environmental Satellite Service  

NASA Technical Reports Server (NTRS)

The national Environmental Satellite Service (NESS) receives data at periodic intervals from satellites of the Synchronous Meteorological Satellite/Geostationary Operational Environmental Satellite series and from the Improved TIROS (Television Infrared Observational Satellite) Operational Satellite. Within the conterminous United States, direct readout and processed products are distributed to users over facsimile networks from a central processing and data distribution facility. In addition, the NESS Satellite Field Stations analyze, interpret, and distribute processed geostationary satellite products to regional weather service activities.

1977-01-01

357

75 FR 20389 - Resinoid Engineering Corporation Hebron, OH; Resinoid Engineering Corporation Heath, OH; Amended...  

Federal Register 2010, 2011, 2012, 2013

...TA-W-71,175; TA-W-71,175A] Resinoid Engineering Corporation Hebron, OH; Resinoid Engineering Corporation Heath, OH; Amended Certification...2010, applicable to workers of Resinoid Engineering Corporation, Hebron, Ohio. The...

2010-04-19

358

76 FR 35024 - Precision Dynamics Corporation San Fernando, CA; Precision Dynamics Corporation, Also Known as...  

Federal Register 2010, 2011, 2012, 2013

...Dynamics Corporation, Also Known as the St. John Companies, Valencia, CA; Amended Certification...Dynamics Corporation, also known as The St. John Companies, operated in conjunction with...Dynamics Corporation, also known as The St. John Companies, Valencia, California...

2011-06-15

359

Spectrum agile radio: radio resource measurements for opportunistic spectrum usage  

Microsoft Academic Search

Radio spectrum allocation is undergoing radical rethinking. Regulators, government agencies, industry, and the research community have recently established many initiatives for new spectrum policies and seek approaches to more efficiently manage the radio spectrum. In this paper, we examine new approaches, namely, spectrum agile radios, for opportunistic spectrum usage. Spectrum agile radios use parts of the radio spectrum that were

Stefan Mangold; Zhun Zhong; Kiran Challapali; Chun-Ting Chou

2004-01-01

360

Exploration of the Saturnian System with Cassini Radio Science  

NASA Technical Reports Server (NTRS)

The ongoing Galileo mission has provided many new insights into the Jovian system. Among them are new discoveries from the Radio Science investigations , including multiple measurements of the Jovian ionosphere, the ionospheres and plasma environments of Io, Europa, Ganymede, and Callisto, and the internal structure of the Galilean satellites. The Cassini spacecraft, which will be placed in orbit about Saturn in 2004, will conduct Radio Science investigations of many aspects of the Saturnian system with a radio instrument of unprecedented stability and versatility. It will use radio links at three wavelengths : S-band(13 cm), X-band (3.5 cm), and Ka-band (1 cm) to probe the atmospheres and ionospheres of Saturn and Titan and Saturn's rings by means of radio occultations, and to measure the masses and gravity fields of Saturn, Titan, and selected icy satellites by precision tracking. In addition, the stability of the radio instrument will be utilized to conduct a search for gravitational waves during solar oppositions, and to precisely measure general relativistic effects during solar conjunctions during the interplanetary cruise prior to arrival at Saturn.

Kliore, Arvydas J.

1999-01-01

361

Mobile satellite communications in the Forest Service  

NASA Technical Reports Server (NTRS)

There are usually some places within a forest that do not have adequate communication coverage due to line-of-sight or other reasons. These areas are generally known by the foresters and radio technicians and allowances are made for that when working or traveling in those areas. However, when wildfire or other emergencies occur, communications are vital because wildfires can require hundreds of firefighters and cover thousands of acres. During these emergency operations, the existing communications are not adequate and complete radio systems are moved into the area for the conduct of fire communications. Incident command posts (ICPs) and fire camps are set up in remote locations and there is constant need for communications in the fire area and to agency headquarters and dispatch offices. Mobile satellite communications would be an ideal supplement to the Forest Service's current communications system in aiding forest fire control activities.

Warren, John R.

1988-01-01

362

Operating frequencies for educational satellite services  

NASA Technical Reports Server (NTRS)

The factors affecting the choice of transmission frequencies are identified. These include international radio regulations, natural environment, man-made environment, hardware considerations, and interconnection and spectrum space considerations. An analysis is presented of international radio regulations with emphasis on 1963 EARC and 1971 WARC frequency allocations, powerflux density restrictions, and resolutions concerning introduction of broadcasting-satellite systems. Natural-environmental effects were divided into two categories: (1) those due to transionospheric propagation, and (2) those that can be credited to the earth's atmosphere and its constituents. The frequency dependence of the signal attenuation, signal distortion, and contributions to system noise temperature due to environmental effects are discussed, and comparisons were made for frequencies of interest. Man-made environmental effects were examined in terms of various sharing limitations as well as the indigenous noise contribution to the overall system noise.

Singh, J. P.

1971-01-01

363

Radio frequency observations of lightning discharges by the forte satellite.  

SciTech Connect

FORTE-observed VHF signatures for different lightning discharges are presented. For in-cloud discharges, a pulse pair is typically recorded and is named a 'transionospheric pulse pair' (TIPP). Many intense TIPPs are coherent and polarized, whereas initial and dart leaders do not show a recognizable degree of polarization. TIPPs are optically weaker than cloud-to-ground (CG) strokes, and stronger VHF TIPPs are optically darker. About 10% of CG strokes, mostly over seawater, produce extremely narrow, powerful VHF pulses at the very beginning of the return strokes. These narrow pulses are found to form an upward beam pattern.

Shao, X. (Xuan-Min); Jacobson, A. R.; Light, T. (Tracy E.); Suszcynsky, D. M. (David M.)

2002-01-01

364

American RadioWorks  

NSDL National Science Digital Library

Radio documentaries have been around almost since the beginning of regularly scheduled radio programming, but not all are created equal (or with great aplomb), and the American Radio Works is certainly one of the finer documentary production units in the field. Based at Minnesota Public Radio in St. Paul, Minnesota, Radio Works' primary themes include public affairs documentaries on major social and economic issues, investigative reporting, and the Living History series, which seeks to document the 20th century American experience "through the lives of those who witnessed it." The web-browsing public will be glad to know that all of the radio projects are available online here, and can be listened to in their entirety. Visitors can listen to close to 40 of their productions, including their most recent production which deals with the extensive phone conversations recorded by Presidents Johnson, Kennedy, and Nixon during their terms in the White House

365

Neptune's small inner satellites  

NASA Astrophysics Data System (ADS)

The six small inner satellites of Neptune discovered by Voyager 2 are described. Proteus (1989N1), the largest of these sattelites, has a mean radius of 208 +/-8 km, while the radius of the smallest, Naiad (1989N6), is 29 +/-6 km. The inner satellite system of Neptune is similar to that of Uranus in that the albedos of the satellites are effectively the same (four of the Neptune's satellites have geometric albedos of 0.06 at 0.48 micron), the sizes are similar, and some have orbits within the region of planetary rings. The two largest satellites of this group are resolved as irregular objects; they have limb roughnesses comparable to those of similarly sized satellites of other planets.

Thomas, Peter; Veverka, Joseph

1991-10-01

366

The 1992 World Administrative Radio Conference: Technology and Policy Implications  

NASA Astrophysics Data System (ADS)

As the 20th century draws to a close, new radio technologies and services are poised to change the ways we communicate. Radio waves already make possible a wide range of services considered commonplace--AM and FM radio broadcasting, television, cellular telephones, remote garage-door openers, and baby monitors. Advances in radio technology are giving birth to even more new products and services, including pocket-sized telephones that may allow people to make and receive calls anywhere in the world, high-definition televisions (HDTV) with superior quality pictures and sound, and static-free digital radios. The 1992 World Administrative Radio Conference (WARC-92) authorized frequencies for many of these new radio communication services, and granted additional frequencies for many existing services, including international broadcasting, satellite-based mobile communications, and communications in space. The effects of these changes will be felt well into the 21st century as countries around the world develop and deploy new communications systems to serve the needs of consumers, businesses, and governments. For the United States, the decisions made at the conference will critically affect how we develop new radio technologies and applications, how competitive this country will be in radio communications equipment and services, and how effectively the United States can exercise its role as a leader in world radio communication policymaking. This study of the outcomes and implications of WARC-92 was requested by the House Committee on Energy and Commerce and the Senate Committee on Commerce, Science, and Transportation. OTA was asked to evaluate the success of U.S. proposals at the conference, discuss the implications of the decisions made for U.S. technology and policy development, and identify options for improving U.S. participation in future world radio communication conferences.

1993-05-01

367

Mapping the Galilean satellites of Jupiter with Voyager data.  

USGS Publications Warehouse

The four Galilean satellites of Jupiter are being mapped using image data from the Voyager 1 and 2 spacecraft. The maps are published at several scales and in several versions. Preliminary maps at 1:25,000,000-required for mission planning and preliminary science reports-were compiled within three weeks of data acquisition and have been published. Later maps incorporate Rand Corporation photogrammetric triangulations. - from Authors

Batson, R.M.

1980-01-01

368

Radio-Locator  

NSDL National Science Digital Library

Radio-Locator is a comprehensive database of radio stations throughout the United States and Canada. Stations can be searched by location and format, or even more specifically with the site's advanced search. Users can even search for vacant frequencies on the dial. The bulk of their information come from the FCC's public databases, but is also updated and corrected. Radio-Locator also provides links to individual stations website and internet streams if available.

369

Dominion Radio Astrophysical Observatory  

NASA Astrophysics Data System (ADS)

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

Murdin, P.

2000-11-01

370

National Radio Observatory  

NSDL National Science Digital Library

The National Radio Astronomy Observatory (NRAO) "operates powerful, advanced radio telescopes spanning the western hemisphere." The website is nicely divided into information for the general public, astronomers, and teachers and students. Users can learn all about NRAO's many telescopes located throughout the United States. Researchers can find out about meetings, conferences, software resources, and surveys. Amateur radio astronomers can find links describing how to build antennas and interferometers. Everyone will enjoy the numerous images of astronomical phenomena and NRAO's telescopes and facilities.

371

Satellite Communications with NRAO Green Bank Antennas  

NASA Astrophysics Data System (ADS)

The National Radio Astronomy Observatory's Green Bank facility has several medium and large antennas that are available for satellite communications. The 100 meter Robert C. Byrd Green Bank Telescope (GBT), the largest and most sensitive antenna on site, is capable of receiving signals at frequencies as high as 86 GHz. In addition to the GBT are the fully operational 43 meter, 20 meter, and 13.7 meter antennas, and three mothballed 26 meter antennas. A transmitter could be fitted to any of these antennas for spacecraft uplinks. We discuss the characteristics of these antennas and possible operational models for future planetary science mission support.

Ford, John M.; Ford, H. Alyson; Watts, Galen

2014-11-01

372

The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07) 1-4244-1144-0/07/$25.00 2007 IEEE.  

E-print Network

or simply SITs. The DVB-RCS Hub is vital for the operation of the DVB-RCS satellite communications network the new developments in satellite networks such as DVB-RCS. In fact, satellite communication systemsThe 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

Vouyioukas, Demosthenes

373

Television satellite programs  

Microsoft Academic Search

Why and how satellite television transmission is being done, especially TDF-1\\/TV-Sat, are considered. The need for satellite television is assessed in terms of extending areas of reception. Problems of optimal signal strength, installation cost, and spillover are assessed. Political, cultural, and commercial aspects are also covered. Diverse satellite television systems to date are compared. The TDF-1\\/TV-Sat program is outlined as

P. Usunier

1981-01-01

374

SERIES - Satellite Emission Range Inferred Earth Surveying  

NASA Technical Reports Server (NTRS)

The Satellite Emission Range Inferred Earth Surveying (SERIES) concept is based on the utilization of NAVSTAR Global Positioning System (GPS) radio transmissions without any satellite modifications and in a totally passive mode. The SERIES stations are equipped with lightweight 1.5 m diameter dish antennas mounted on trailers. A series baseline measurement accuracy demonstration is considered, taking into account a 100 meter baseline estimation from approximately one hour of differential Doppler data. It is planned to conduct the next phase of experiments on a 150 m baseline. Attention is given to details regarding future baseline measurement accuracy demonstrations, aspects of ionospheric calibration in connection with subdecimeter baseline accuracy requirements of geodesy, and advantages related to the use of the differential Doppler or pseudoranging mode.

Macdoran, P. F.; Spitzmesser, D. J.; Buennagel, L. A.

1983-01-01

375

New options for satellite power systems /SPS/  

NASA Technical Reports Server (NTRS)

The operation of a satellite power system (SPS) involves the conversion of solar energy into electrical energy with the aid of facilities carried by a geosynchronous satellite, the transmission of the obtained energy to earth in the form of microwave radio frequency energy, and the conversion of the energy received on earth into dc current for distribution into the network. Attention is given to questions concerning suitable microwave radiation density, details of space transportation for the construction of the SPS, and suitable approaches for the transformation of the solar energy into electric energy. It appears that a Rankine cycle using cesium as the main working fluid and a steam bottoming cycle might have advantages over a Brayton cycle concept considered earlier. In the area of solar photovoltaic concepts GaAlAs cells have advantages over silicon cells related to lighter weight, efficiency, and resistance to space radiation. The required amount of gallium seems to become available.

Hanley, G. M.

1977-01-01

376

Satellite Threat Warning and Attack Reporting  

SciTech Connect

The Air Force Research Laboratory`s Satellite Threat Warning and Attack Reporting (STW/AR) program will provide technologies for advanced threat warning and reporting of radio frequency (RF) and laser threats. The STW/AR program objectives are: (a) develop cost- effective technologies to detect, identify, locate, characterize, and report attacks or interference against U.S. and Allied satellites. (b) demonstrate innovative, light-weight, low-power, laser and RF sensors. The program focuses on the demonstration of RF and laser sensors. The RF sensor effort includes the investigation of interferometric antenna arrays, multi-arm spiral and butler matrix antennas, wideband receivers, adaptive processors, and improved processing algorithms. The laser sensor effort includes the investigation of alternative detectors, broadband grating and optical designs, active pixel sensing, and improved processing algorithms.

Hilland, D. [Kirkland AFB, NM (United States). Air Force Research Lab.; Phipps, G. [Sandia National Labs., Albuquerque, NM (United States). Optics & Technologies Dept.; Jingle, C.; Newton, G. [Schafer Corp., Albuquerque, NM (United States)

1997-12-31

377

A direct broadcast satellite-audio experiment  

NASA Technical Reports Server (NTRS)

System studies have been carried out over the past three years at the Jet Propulsion Laboratory (JPL) on digital audio broadcasting (DAB) via satellite. The thrust of the work to date has been on designing power and bandwidth efficient systems capable of providing reliable service to fixed, mobile, and portable radios. It is very difficult to predict performance in an environment which produces random periods of signal blockage, such as encountered in mobile reception where a vehicle can quickly move from one type of terrain to another. For this reason, some signal blockage mitigation techniques were built into an experimental DAB system and a satellite experiment was conducted to obtain both qualitative and quantitative measures of performance in a range of reception environments. This paper presents results from the experiment and some conclusions on the effectiveness of these blockage mitigation techniques.

Vaisnys, Arvydas; Abbe, Brian; Motamedi, Masoud

1992-01-01

378

Approved Module Information for EE402B, 2014/5 Module Title/Name: Radio Systems and Personal  

E-print Network

Communications Systems: Introduce practical radio communications systems such as satellite and mobile Communications Systems Module Code: EE402B School: Engineering and Applied Science Module Type: Standard Module. MSc Wireless Communications & Networking. MSc Photonic Networks Engineering (MAPNET). Available

Neirotti, Juan Pablo

379

STEM on the radio  

NASA Astrophysics Data System (ADS)

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/.

Showstack, Randy

2011-10-01

380

How Satellites See  

NSDL National Science Digital Library

This lesson allows students to compare and contrast three NASA satellites: The Extreme Ultraviolet Explorer (EUVE), The Cosmic Background Explorer (COBE), and the Hubble Space Telescope (HST). The lesson includes access to data and images from these three NASA astronomy satellites, contrasting the way the sky appears in three very different electromagnetic wavelengths or colors of light. Other satellite information is included, but the focus is a simple introduction to the electromagnetic spectrum as used by the three space observatories. While participating in this activity, students will compare physical parts and orbits of each satellite and participate in hands-on experiments to begin to understand visible, infrared and ultraviolet wavelengths.

381

Polar Operational Environmental Satellite  

NSDL National Science Digital Library

The National Oceanic & Atmospheric Administration (NOAA) operates POES, the Polar Operational Environmental Satellite system. Comprised of several components (namely, the Advanced Very High Resolution Radiometer (AVHRR) and the Tiros Operational Vertical Sounder (TOVS)), these satellites make nearly polar orbits daily, providing global coverage of land, ocean, and atmospheric data. The POES Website includes an overview of the satellite system and lists data types such as vegetation index, sea surface temperature charts, volcanic eruption clouds, and much more. For researchers interested in environmental monitoring using satellite-based data, the POES Webpage will serve as a useful reference point.

382

Equalizers for communications satellites  

E-print Network

This thesis investigates equalization for advanced protected satellite communications systems in development at MIT Lincoln Laboratory. Equalizers facilitate high data rate communication by correcting dispersion in the ...

Fay, Leon

2008-01-01

383

Satellite Antenna Systems  

NASA Technical Reports Server (NTRS)

Through the Technology Affiliates Program at the Jet Propulsion Laboratory, the ACTS antenna system was transferred from experimental testing status to commercial development with KVH Industries, Inc. The ACTS design enables mobile satellite antennas to remain pointed at the satellite, regardless of the motion or vibration on which it is mounted. KVH's first product based on the ACTS design is a land-mobile satellite antenna system that will enable direct broadcast satellite television aboard moving trucks, recreational vehicles, trains, and buses. Future products could include use in broadcasting, emergency medical and military vehicles.

1997-01-01

384

Sputnik 1 and the First Satellite Ionospheric Experiment  

NASA Astrophysics Data System (ADS)

The world's first scientific space experiment was carried out in 1957 during the flight of the first Artificial Earth Satellite (AES) - Sputnik 1. It was an ionospheric experiment performed at IZMIRAN under the direction of Prof. Ya.L.Alpert (1911-2010). The sunrise and sunset variations in the AES radio signal were recorded in order to determine the distribution of electron density in the topside ionosphere (above the maximum). The experiment demonstrated the capabilities of the satellite radio beacon method, which is now very important and widely used for studying the ionosphere. Our report submitted to the COSPAR General Assembly in Russia describes the history and results of that experiment, as well as some other contributions by Ya.L.Alpert to ionospheric research. Yakov L.Alpert was one of the most famous and influential radiophysicists of his time, the author of many fundamental studies and of a number of classic books on the theory of propagation of electromagnetic waves, interaction of artificial bodies with ionospheric plasmas, ionospheric radio scattering, and the use of satellite radio beacon methods for studying the ionosphere.

Sinelnikov, Vyacheslav; Kuznetsov, Vladimir; Alpert, Svetlana

385

Satellite to satellite tracking error analysis studies and data processing  

NASA Technical Reports Server (NTRS)

An error analysis was conducted to examine the effects of placing the target satellite in an orbit nearly coplanar with the relay satellite and of data span length on the accuracy with which the satellite states can be recovered. An analysis of error models using actual satellite to satellite tracking data spans is included. Results are tabulated.

Ayres, C. L.; Rosenblatt, G.

1975-01-01

386

Radio Frequency Interference and the National Radio Astronomy Observatory  

NASA Astrophysics Data System (ADS)

Radio frequency interference (RFI) and radio astronomy have been closely linked since the emergence of radio astronomy as a scientific discipline in the 1930s. Even before the official establishment of the National Radio Astronomy Observatory, protection against contemporary and future radio noise levels was seen as crucial to ensure success of any new observatory. My talk will examine the various local, regional, national, and international efforts enacted to protect NRAO and other American radio astronomy sites from RFI.

Smith, Sierra

2014-01-01

387

Solar Radio Bursts with Drifting Stripes in Emission and Absorption  

NASA Astrophysics Data System (ADS)

This review covers fairly comprehensively experimental and theoretical research on the fine structure of types zebra pattern (ZP) and fiber bursts (FB) in solar type II + IV radio bursts. The basic attention is given to the latest experimental data. A comparative analysis of several recent solar type IV radio outbursts with these fine structure in dynamical radio spectra is carried out using available ground-based and satellite data (Yohkoh, SOHO, TRACE, RHESSI). New data on microwave zebra structures and fiber bursts testifies that they are analogous to similar structures observed at meter wavelengths. The discovery of the superfine structure, in the form of millisecond spikes is the most significant new effect in the cm range. All basic theoretical models of the zebra pattern and fiber bursts are discussed critically. Two main models are studied for their interpretation: (i) interactions between electrostatic plasma waves and whistlers, (ii) radio emission at double plasma resonance (DPR). The relative significance of several possible mechanisms remains uncertain.

Chernov, G. P.

2006-12-01

388

A Small Radio Telescope for Instructional Purposes  

NASA Astrophysics Data System (ADS)

Radio astronomers nowadays have a number of excellent instruments to choose from for their research projects, such as the VLA, VLBA, Arecibo,etc. However, these instruments do not readily furnish the opportunity for student instruction in the technical aspects of radio astronomy that was available twenty five years ago or more. Such experience can in part be provided by small dedicated telescopes at universities. Such a radiotelescope has been installed at the University of Iowa. A commercial 4.5 meter satellite TV antenna has been modified to work as a radiotelescope. The radio telescope operates as a transit instrument, with computer control of elevation pointing. Working receivers exist at 5.0 and 1.4 GHz. Components exist for construction of receivers at 610 MHz and 15.0 GHz. Observations to date have been made of the Sun, Moon, Crab Nebula, and galactic HI. We have recently installed a mechanical switch in the 5 GHz front end, built switching electronics, and written a Labview virtual instrument to provide a Dicke radiometer. In the immediate future we plan to use this instrument to repeat the determination of the 5.0 GHz radio phase function of the Moon. Our presentation will include information on commercial sources of critical components for the system, such as low loss RF cables, low insertion loss mechanical switches, low noise amplifiers, etc.

Spangler, S. R.; Wurster, J. E.; Nellermoe, B. L.

1996-12-01

389

Science Priorities of the RadioAstron Space VLBI Mission  

NASA Astrophysics Data System (ADS)

The main scientific goal of the RadioAstron Space VLBI mission is study of Active Galactic Nuclei (AGN), Masers and other astronomical objects with unprecedented angular resolution, up to few millionths of an arc-second. The resolution achieved with RadioAstron will allow study the following phenomena and problems: * Central engine of AGN and physical processes near super massive black holes providing an acceleration of cosmic rays size, velocity and shape of emitting region in the core, spectrum, polarization and variability of emitting components; * Cosmological models, dark matter and dark energy by studying dependence of above mentioned AGN's parameters with redshift, and by observing gravitational lensing; * Structure and dynamics of star and planets forming regions in our Galaxy and in AGN by studying maser and Mega maser radio emission; * Neutron (quark?) stars and black holes in our Galaxy, their structure and dynamics by VLBI and measurements of visibility scintillations, proper motions and parallaxes; * Structure and distribution of interstellar and interplanetary plasma by fringe visibility scintillations of pulsars; The RadioAstron mission uses the satellite SPECTR (astrophysical module), developed by Lavochkin Association of Russian Aviation and Space Agency (RASA). This module will be used in several other scientific missions. The total mass of the scientific payload is about 2500 kg, of which the unfolding parabolic 10-m radio astronomy antenna's mass is about 1500 kg, and scientific package holding the receivers, power supply, synthesizers, control units, frequency standards and data transmission radio system. The mass of the whole system (satellite and scientific payload) to be carried into orbit by the powerful "Zenit-2SB"-"Fregat-2CB" launcher is about 5000 kg. The RadioAstron project is an international collaboration between RASA and ground radio telescope facilities around the world.

Langston, Glen; Kardashev, N.; International Space VLBI Collaboration

2006-12-01

390

Radio Frequency Interference: Radio Astronomy's Biggest Enemy  

NASA Astrophysics Data System (ADS)

As technology progresses, the demand for the usage of the electromagnetic spectrum increases with it. The development is so fast and prolific that clean band space for passive users such as Radio Astronomy is becoming ever so scarce. Even though, several spectral bands have been protected for Radio Astronomy by Federal Communication Commission (in the USA) under the recommendations of the International Telecommunication Union (ITU), pressure for making more spectral space commercially usable is extreme. Although these commercial usages make our modern living at all possible, often the extreme vulnerability of passive users are are not fully appreciated, resulting in unwanted emissions (RFI) in the Radio Astronomy Bands. Another source of RFI is the fact that many of the electronic devices used in the observatories themselves generate radio waves. If proper precautions are not taken, these can be received back through the Radio Telescope itself. This problem is referred to as internal RFI. The focus of this paper is the search and diminution of internal RFI in the Arecibo Observatory in Arecibo, Puerto Rico. Using a simple setup of a log-periodic antenna and a Spectrum Analyzer, spectra spanning a frequency range of 100 - 1800 MHZ were recorded in some areas of the Observatory and the new Visitor Center (AOVEF). The measurements disclosed sources of radio emission among some of the digital electronic equipment in the Equipment room and a few displays in the AOVEF. Most prominent of these was a 2.5 MHz comb spanning the entire range of the measurements emitted from the SRENDIP and AOFTM machines. The respective groups were informed and corrective shielding & isolations were implemented immediately. In AOVEF, three displays, some audio-visual equipment, and video/digital cameras used by the visitors were found to be "leaky". In future, the use of such cameras will be prohibited and the exhibits will be screened appropriately.

Acevedo, F.; Ghosh, Tapasi

1997-12-01

391

TIDs over Tucuman by GPS radio interferometry  

NASA Astrophysics Data System (ADS)

This paper presents some results investigating the new possibilities of radio interferometry of Travelling Ionospheric Disturbances (TIDs) that are based on exploiting standard measurements of transionospheric radio signal characteristics and coordinate-time measurements using dual-frequency multichannel receivers of the Global Positioning System (GPS). We consider some methods of reconstructing TID characteristics, which were used in classical radio interferometry and can be useful when processing GPS data. Let us consider an interferometer that consist of three receivers, installed at vertexes of triangle on Tucuman (2649' 00" S ;6513' 00" W) with sides oriented to the north and east. A Statistical Angle-of-arrival and Doppler Method for GPS radio interferometry is proposed for determining the characteristics of the TIDs dynamics by measuring variations of GPS phase derivatives with respect to time and spatial coordinates. These data are used to calculate corresponding values of the velocity vector, in view of a correction for satellite motions based on the current information available regarding the angular coordinates of the satellites. Our findings show that : a) We learnt that Gravity Waves (GW) can be measured with a system of 3 closely located GPS receivers, b) It is possible to detect the angle of arrival, velocity, and period of the GWs, c) Attention has to be paid to cases when there are TEC depletions as they can be mistaken by GWs, d) To avoid a false detection is possible to use a spectral analysis that will help us differentiate between perturbations that are moving with different velocities.

Rios, Victor

392

MIMO over Satellite: A Review  

Microsoft Academic Search

The present article carries out a review of MIMO- based techniques that have been recently proposed for satellite communications. Due to the plethora of MIMO interpretations in terrestrial systems and the particularities of satellite communica- tions, this review is built on two pillars, namely fixed satellite and mobile satellite. Special attention is given to the characteristics of the satellite channel,

Pantelis-Daniel Arapoglou; Konstantinos Liolis; Massimo Bertinelli; Athanasios Panagopoulos; Panayotis Cottis; Riccardo De Gaudenzi

2011-01-01

393

Outer planets satellites  

NASA Technical Reports Server (NTRS)

The present investigation takes into account the published literature on outer planet satellites for 1979-1982. It is pointed out that all but three (the moon and the two Martian satellites) of the known planetary satellites are found in the outer solar system. Most of these are associated with the three regular satellite systems of Jupiter, Saturn, and Uranus. The largest satellites are Titan in the Saturn system and Ganymede and Callisto in the Jupiter system. Intermediate in size between Mercury and Mars, each has a diameter of about 5000 km. Presumably each has an internal composition about 60 percent rock and 40 ice, and each is differentiated with a dense core extending out about 75 percent of the distance to the surface, with a mantle of high-pressure ice and a crust of ordinary ice perhaps 100 km thick. Attention is also given to Io, Europa, the icy satellites of Saturn, the satellites of Uranus, the small satellites of Jupiter and Saturn, Triton and the Pluto system, and plans for future studies.

Morrison, D.

1983-01-01

394

Efficient Packet Satellite Communications  

Microsoft Academic Search

This paper gives an extensive analysis of a Packet satellite (PACSAT) communications system that uses a digital processing satellite in a packet data network. It is shown that multiple uplinks coupled with on-board switching and storage can provide significant gains in throughput, efficiency, and margin against instability. Design tradeoffs are presented and the theoretical results are verified by extensive computer

JOSEPH K. DEROSA; LAWRENCE H. OZAROW; LESLIE N. WEINER

1979-01-01

395

Mobile satellite communications  

Microsoft Academic Search

The paper presents an up-to-date overview as well as new results on mobile satellite communications. Specifically, the following subjects are addressed: worldwide activities; satellite orbits; multiple access techniques; Novstar global positioning system; economic and regulatory issues; future trends. Some of these technical and nontechnical subjects appeal disjoint, but they are unique and significant among the many facets, which effect the

W. W. Wu; E. F. Miller; W. L. Pritchard; R. L. Pickholtz

1994-01-01

396

Engineer a Satellite  

NSDL National Science Digital Library

In this activity, learners select the scientific instruments for their satellite, calculate the power requirements for all the subsystems, and construct a scale model of their very own Earth observing satellite using building blocks and/or Legos. Includes instructions and worksheets.

2012-08-26

397

Communications technology satellite  

NASA Technical Reports Server (NTRS)

A description of the Communications Technology Satellite (CTS), its planned orbit, its experiments, and associated ground facilities was given. The communication experiments, to be carried out by a variety of groups in both the United States and Canada, include tele-education, tele-medicine, community interaction, data communications and broadcasting. A historical summary of communications satellite development was also included.

1976-01-01

398

ASTER's Satellite Image Gallery  

NSDL National Science Digital Library

This site provides access to satellite images acquired by NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer satellite. The images are sorted into eight categories: Archeology, Cities, Geology, Hydrology, Land Use, Natural Hazards, and Volcanoes. Users can also view the most popular images and the most recent additions to the gallery.

Laboratory, Nasa J.

399

Signals from Communications Satellites.  

ERIC Educational Resources Information Center

Discusses the Doppler effect for relative motion between a source of waves and an observer and the orbital dynamics of communications satellites. Presents preliminary calculations of the satellite's altitude and linear velocity using only the concepts of the Doppler shift and the mechanics of motion in a circular path. (JRH)

Thomsen, Volker

1996-01-01

400

Jovian satellite nomenclature  

NASA Technical Reports Server (NTRS)

A brief review of the history of Jovian satellite nomenclature is given to indicate the background for the names proposed for the numbered satellites. The new names are consistent with established tradition and should cause minimal confusion with other named objects in the solar system.

Owen, T.

1976-01-01

401

Tethered satellite control mechanism  

NASA Technical Reports Server (NTRS)

The tethered satellite control mechanisms consist of four major subsystems. The reel drive mechanism stores the tether. It is motor driven and includes a level wind to uniformly feed the tether to the reel. The lower boom mechanism serves two primary functions: (1) it measures tether length and velocity as the tether runs through the mechanism, and (2) it reads the tether tension at the reel. It also provides change the direction for the tether from the reel to the upper boom mechanism. The deployment boom positions the upper boom mechanism with satellite out of the cargo bay. The deployment function places the 500-kg satellite 20 m away from the Space Shuttle (producing a small natural gravity gradient force), impacts an initial velocity to the satellite for deployment, and allows for satellite docking at a safe distance from the body of the Space Shuttle. The upper boom mechanism (UBM) services three functions: (1) it provides tether control to the satellite as the satellite swings in and out of plane; (2) it reads tether tension in the low range during the early deployment and final retrieval parts of the mission; and (3) it produces additional tether tension at the reel when tether tension to the satellite is in the low range.

Kyrias, G. M.

1983-01-01

402

Audio direct broadcast satellites  

NASA Technical Reports Server (NTRS)

Satellite sound broadcasting is, as the name implies, the use of satellite techniques and technology to broadcast directly from space to low-cost, consumer-quality receivers the types of sound programs commonly received in the AM and FM broadcast bands. It would be a ubiquitous service available to the general public in the home, in the car, and out in the open.

Miller, J. E.

1983-01-01

403

The First Wave: The Beginnings of Radio in Canadian Distance Education  

ERIC Educational Resources Information Center

This article describes one of the first developments and deployment of radio for distance learning and education in Canada, beginning in the early 1920s. Anticipating a recent initiative of public-private partnerships, the impetus, infrastructure, and initial programs were provided by a large corporation. Description of the system, its purpose,

Buck, George H.

2006-01-01

404

The Radio Universe  

NSDL National Science Digital Library

The Radio Universe website provides a brief introduction the electromagnetic radiation, HII regions, the structure of the Milky Way galaxy, and quasars as seen by radio wave observations. The site also contains an expliantion of the doppler effect and 21 cm line.

2005-06-07

405

Stabilized radio frequency quadrupole  

DOEpatents

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

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

1984-12-25

406

Imaging the Radio Universe  

E-print Network

-rays, and microwaves, etc). · Sound waves are pressure waves. Require a medium (air, water, etc.) to travel through. · Sound is created by a pressure wave moving a membrane in your ear. Your brain turns the vibration of this membrane into "sound". MediumEar Sound Radio Waves are not Sound Waves #12;You do not listen to radio waves

Groppi, Christopher

407

Radio astronomy receivers  

Microsoft Academic Search

A general survey of the principles of radio astronomy receivers is presented. System noise temperature, the sensitivity of different receiver types, and the calibration of receivers are studied. A total-power receiver is analyzed as a basic radio telescope receiver and the results are used to obtain the performance of other receiver types such as the Dicke receiver, Graham's receiver, correlation

M. Tiuri

1964-01-01

408

Pulsating Solar Radio Emission  

NASA Astrophysics Data System (ADS)

A status report of current research on pulsating radio emission is given, based on working group discussions at the CESRA 2004 workshop. Quasi-periodic pulsations have been observed at all wavelength ranges of the radio band. Usually, they are associated with flare events; however since the late 90s, pulsations of the slowly-varying component of the Suns radio emission have also been observed. Radio pulsations show a large variety in their periods, bandwidths, amplitudes, temporal and spatial signatures. Most of them have been attributed to MHD oscillations?dex waves!MHD waves in coronal loops, while alternative interpretations consider intrinsic oscillations of a nonlinear regime of kinetic plasma instabilities or modulation of the electron acceleration. Combined radio spectroscopic observations with radio imaging and X-ray/EUV data have revived interest in the subject. We summarize recent progress in using radio pulsations as a powerful tool for coronal plasma and magnetic field diagnostics. Also the latest developments on the study of the physical processes leading to radio emission modulation are summarized.

Nindos, Alexander; Aurass, Henry

409

The Radio Transient Sky  

Microsoft Academic Search

Transient radio sources are necessarily compact and usually are the locations of explosive or dynamic events, therefore offering unique opportunities for probing fundamental physics and astrophysics. In addition, short-duration transients are powerful probes of intervening media owing to dispersion, scattering, and Faraday rotation that modify the signals. While radio astronomy has an impressive record obtaining high time resolution, usually it

J. Lazio; P. S. Ray; S. Ellingson; S. Close; P. Crane; S. D. Hyman; B. A. Jacoby; W. Junor; N. E. Kassim; S. R. Kulkarni; Y. M. Pihlstrom; G. B. Taylor; D. Werthimer

2006-01-01

410

Radio Transmission Measurements  

Microsoft Academic Search

The paper divides naturally into three sections. The first section briefly analyses the radio transmission circuit into (a) the sending or radiating portion, (b) the transmitting portion consisting of the ether path thru which the radiated waves travel, and (c) the receiving portion. The relation of these from the standpoint of the radio transmission engineer is discussed, pointing out the

R. Bown; C. R. Englund; H. T. Friis

1923-01-01

411

The Radio Jove Project  

NASA Technical Reports Server (NTRS)

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

Thieman, J. R.

2010-01-01

412

Stabilized radio frequency quadrupole  

DOEpatents

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

Lancaster, Henry D. (Orinda, CA); Fugitt, Jock A. (Berkeley, CA); Howard, Donald R. (Danville, CA)

1984-01-01

413

World Ocean Radio  

NSDL National Science Digital Library

World Ocean Radio is a weekly series of five-minute audio essays on a wide range of ocean issues hosted by W2O's own Peter Neill. Available for RSS feed (bottom of page), podcast, and syndicated use at no cost by community radio stations worldwide.

414

A refracting radio telescope  

Microsoft Academic Search

Observations of extraterrestrial radio sources at the lower end of the radio frequency spectrum are limited by reflection of waves from the topside ionosphere and by the large size of antenna apertures necessary for the realization of narrow beamwidths. The use of the ionosphere as a lens is considered. The lens is formed by the release of chemicals such as

Paul Bernhardt; A. V. da Rosa

1977-01-01

415

Corporate governance : the case for Asian REITs  

E-print Network

At the entity level, the design of sound corporate governance mechanisms is critical for REITs that are preparing to go public. At the industry level, issues of transparency and corporate governance are consequential to ...

Tan, Denise, S.M. Massachusetts Institute of Technology

2009-01-01

416

43 CFR 3902.25 - Corporations.  

Code of Federal Regulations, 2013 CFR

...to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) OIL SHALE MANAGEMENT-GENERAL Qualification Requirements 3902.25 Corporations. Corporate officers or...

2013-10-01

417

Corporate Civil Disobedience in the Consumer Interest.  

ERIC Educational Resources Information Center

Through catalytic issue management, corporations proactively seek to affect resolutions of issues in which they have some interest. Corporations now catalyze legal changes by purposely disobeying existing law, facing the associated consequences, and lobbying for desired changes. (Author)

Dennis, Michael R.; And Others

1994-01-01

418

Beyond Compliance: Integrating Nonproliferation into Corporate Sustainability  

SciTech Connect

This paper investigates nonproliferation as a potential corporate sustainability value. It reviews the history of corporate sustainability, builds the case for nonproliferation as a sustainability value, and develops recommendations for the integration of nonproliferation into the frameworks of sustainability.

Hund, Gretchen; Kurzrok, Andrew J.

2013-06-01

419

The Market for Borrowing Corporate Bonds  

E-print Network

This paper describes the market for borrowing corporate bonds using a comprehensive data set from a major lender. The cost of borrowing corporate bonds is comparable to the cost of borrowing stock, between 10 and 20 basis ...

Asquith, Paul

420

22 CFR 96.31 - Corporate structure.  

Code of Federal Regulations, 2010 CFR

...INTERCOUNTRY ADOPTION ACT OF 2000 (IAA) Standards for Convention Accreditation and Approval Licensing and Corporate Governance 96.31 Corporate structure. (a) The agency qualifies for nonprofit tax treatment under section...

2010-04-01

421

Corporate decision analysis : an engineering approach  

E-print Network

We explore corporate decisions and their solutions under uncertainty using engineering methods. Corporate decisions tend to be complex; they are interdisciplinary and defy programmable solutions. To address these challenges, ...

Tang, Victor, Ph.D. Massachusetts Institute of Technology

2006-01-01

422

25 CFR 214.3 - Corporate information.  

Code of Federal Regulations, 2011 CFR

...Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF OSAGE RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS 214.3 Corporate information. A corporation shall file with its first...

2011-04-01

423

25 CFR 214.3 - Corporate information.  

Code of Federal Regulations, 2010 CFR

...Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF OSAGE RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS 214.3 Corporate information. A corporation shall file with its first...

2010-04-01

424

Pseudocoherent Demodulation Of DPSK Radio Signals  

NASA Technical Reports Server (NTRS)

Three schemes for pseudocoherent demodulation of differential-phase-shift keyed (DPSK) radio signals proposed for use in land-mobile/satellite communications. Enables fast reacquisition. Also amounts to compromise between two extremes of coherent demodulation and differentially coherent demodulation, for which bit-error rates greater than those of coherent demodulation by amounts corresponding to difference of about 1 dB in bit-energy/noise-energy ratio. Based on maximum-likelihood estimation and detection during N-symbol observation periods, where N integer typically chosen between 5 and 15.

Divsalar, Dariush; Simon, Marvin K.

1995-01-01

425

Experimental Satellite Quantum Communications  

E-print Network

Quantum Communications on planetary scale require complementary channels including ground and satellite links. The former have progressed up to commercial stage using fiber-cables, while for satellite links, the absence of terminals in orbit has impaired theirs development. However, the demonstration of the feasibility of such links is crucial for designing space payloads and to eventually enable the realization of protocols such as quantum-key-distribution (QKD) and quantum teleportation along satellite-to-ground or intersatellite links. We demonstrated the faithful transmission of qubits from space to ground by exploiting satellite corner cube retroreflectors acting as transmitter in orbit, obtaining a low error rate suitable for QKD. We also propose a two-way QKD protocol exploiting modulated retroreflectors that necessitates a minimal payload on satellite, thus facilitating the expansion of Space Quantum Communications.

Giuseppe Vallone; Davide Bacco; Daniele Dequal; Simone Gaiarin; Vincenza Luceri; Giuseppe Bianco; Paolo Villoresi

2014-06-16

426

Energy Conservation in China North Industries Corporation  

E-print Network

ENERGY CONSERVATION IN CHINA NORTH INDUSTRIES CORPORATION Wang Tian You, Chen Hua De, Jing Xing Chu, Ling Rui Fu, China North Industries Corporation Beijing, People's Republic of China ABSTRACT This paper describes an overview of the energy... conservation in China North Industries Corporation. It shows how the corporation improves energy effi ciencies and how it changes constitution of fuel-- converting oil consumption to coal. Energy management organization, energy balance in plants...

You, W. T.; De, C. H.; Chu, J. X.; Fu, L. R.

427

Dynamical Friction on Satellites  

NASA Astrophysics Data System (ADS)

Deienno et al 2011 (A&A, v.536, A57) investigated the effects of the planetary migration on the satellites of Uranus. We concluded that Uranus might have had more satellites than those observed today. However, due to the Late Heavy Bombardment (LHB) phenomenon, those satellites beyond Oberon were destabilized mostly by collisions involving themselves or with some regular ones. In this work we apply the same methodology for the Saturnian system. We found that the satellites with orbits inside Titan's orbit are immune to the LHB phenomenon. On the other hand, Hyperion, Iapetus, and even Titan, in some cases are strongly affected by the LHB, and depending on the value of Saturn's obliquity, Iapetus might not have resisted to the LHB event. We also found that, the final orbital elements of the surviving satellites differ from what we see today, mainly in inclination. While eccentricity and orbital semi-major axis can be easily damped by tides, for orbital inclinations, tidal effects are not so efficient. Thus, considering that eccentricity and orbital semi-major axis will still evolve by tides, to study the problem of the orbital inclination we consider that: according to our simulations, during the LHB event, collisions between planetesimals and satellites are a common event, causing in some cases destruction of satellites. So, we hypothesized that the material delivered by these catastrophic events could form a disc of particles around the remaining of satellites' orbits. This disc interacts with the remaining satellites and by dynamical friction phenomenon the orbital inclination can be damped. Some preliminary results have shown that, indeed, this tentative can be a viable way to damp conveniently the inclination of some satellites. Acknowledgement: FAPESP-CNPq

Deienno, Rogerio; Yokoyama, T.; Prado, A. F. B. A.

2012-10-01

428

The concept of corporate responsibility  

Microsoft Academic Search

Opening with Ford Motor Company as a case in point, this essay develops a broad and systematic approach to the field of business ethics. After an analysis of the form and content of the concept of responsibility, the author introduces the principle of moral projection as a device for relating ethics to corporate policy. Pitfalls and objections to this strategy

Kenneth E. Goodpaster

1983-01-01

429

Power, ethics, and corporate dentistry.  

PubMed

The North Carolina Dental Association recently sought to place clear statutory limits on the influence of corporate, nondental interests over dentists practices' decision-making. This report describes the two-year legislative battle with well-funded and politically connected parties that ultimately resulted in laws that protect patients' rights to be treated by a dentist free of outside commercial interests. PMID:24761579

Parker, M Alec; Parker, M Alec

2013-01-01

430

FDIC: Federal Deposit Insurance Corporation  

NSDL National Science Digital Library

The U.S. Federal Deposit Insurance Corporation WWW Home Page is open for business. At this site, there is information on the U.S. banking industry, financial information on the condition of the Bank Insurance Fund and the Savings Association Insurance Fund, consumer information, and press releases.

431

Corporate Ownership Structure in Austria  

Microsoft Academic Search

This paper aims to add to the knowledge about ownership structure in Austria. It assesses ownership concentration and the relative importance of the investor categories banks, the state, families, and domestic and foreign firms on the basis of a sample of 600 of the largest non-financial corporations. Balance sheet data, internal rates of return calculations and regression estimates show that

Klaus Gugler

1998-01-01

432

Eclipse of the Public Corporation  

Microsoft Academic Search

The publicly held corporation has outlived its usefulness in manysectors of the economy. New organizations are emerging. Takeovers,leveraged buyouts, and other going-private transactions aremanifestations of this change. A central source of waste in the publiccorporation is the conflict between owners and managers over free cashflow. This conflict helps explain the prominent role of debt in the neworganizations. The new organizations\\

Michael C. Jensen

1989-01-01

433

Lippincott Library Corporate Annual Reports  

NSDL National Science Digital Library

The University of Pennsylvania/ Schoenberg Center for Electronic Text & Image provides facsimiles of historical corporate annual reports from the Lippincott Library collection at this searchable site. Over 40 reports by automotive, department store, food, natural resource, railroad, textile, and utility companies are available mainly from the 1930s and 40s.

434

Communication Technologies in Corporate Settings.  

ERIC Educational Resources Information Center

Examines communication technologies in the workplace, provides a brief overview of current research, and offers questions for further exploration. Offers a personal perspective based on the author's experiences as a product manager for NCR Corporation and as a computer industry consultant. Includes discussions on voice mail, fax, hypermedia, and

Hansen, Craig J.

1992-01-01

435

Hindawi Publishing Corporation Prostate Cancer  

E-print Network

Hindawi Publishing Corporation Prostate Cancer Volume 2011, Article ID 176164, 7 pages doi:10.1155/2011/176164 Clinical Study Effect of Zoledronic Acid on Bone Mineral Density in Men with Prostate Cancer Receiving cancer is well recognized. We assessed the effects of quarterly infusion of zoledronic acid on bone

Ahn, Hongshik

436

Corporate Headquarters Cisco Systems, Inc.  

E-print Network

Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 Cisco Cable Modem Termination System Feature OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY. The Cisco implementation of TCP header

Westall, James M.

437

Corporate Headquarters Cisco Systems, Inc.  

E-print Network

Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 Cisco IP Phone 7960G and 7940G User Guide Text YOUR CISCO REPRESENTATIVE FOR A COPY. The following information is for FCC compliance of Class

Brody, James P.

438

Corporate Headquarters Cisco Systems, Inc.  

E-print Network

Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 Cisco Broadband Cable Command Reference Guide OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY. The Cisco implementation of TCP header

Westall, James M.

439

Corporate Headquarters Cisco Systems, Inc.  

E-print Network

Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 Cisco 7920 Wireless IP Phone Design OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY. The Cisco implementation of TCP header

Westall, James M.

440

Agency, Information and Corporate Investment  

Microsoft Academic Search

This essay surveys the body of research that asks how the efficiency of corporate investment is influenced by problems of asymmetric information and agency. I organize the material around two basic questions. First, does the external capital market channel the right amount of money to each firm? That is, does the market get across-firm allocations right, so that the marginal

Jeremy C. Stein

2001-01-01

441

Executive Compensation and Corporate Fraud  

Microsoft Academic Search

We examine the relation between executive compensation and corporate fraud. Executives at fraud firms have significantly larger equity-based compensation and greater financial incentives to commit fraud than do executives at industry- and size- matched control firms. Executives at fraud firms also earn significantly more total compensation by exercising significantly larger fractions of their vested options than the control executives during

Shane A. Johnson; Harley E. Ryan; Yisong S. Tian

2003-01-01

442

Internship opportunity with URS Corporation  

E-print Network

Internship opportunity with URS Corporation URS is the largest global engineering design firm of undergraduate studies to participate in an internship program with the School of Ocean & Earth Science & Technology (SOEST) at the University of Hawaii. The intent of the internship is two-fold: · To establish

443

Liquidity Risk Premia in Corporate Bond Markets  

Microsoft Academic Search

This paper explores the role of liquidity risk in the pricing of corporate bonds. We show that corporate bond returns have signicant exposures to uctuations in treasury bond liquidity and equity market liquidity. Further, this liquidity risk is a priced factor for the expected returns on corporate bonds, and the associated liquidity risk premia help to explain the credit spread

Frank de Jong; Joost Driessen

444

Corporate governance in China: An overview  

Microsoft Academic Search

Corporate governance (gongsi zhili) is a concept whose time seems definitely to have come in China. Chinese definitions of corporate governance in the abstract tend to cover the system regulating relationships among all parties with interests in a business organization, usually spelling out shareholders as a particularly important group (e.g., Liu, 1999; Yin, 1999). But Chinese corporate governance discourse in

Donald C. Clarke

2003-01-01

445

Corporate governance Legal fiction or economic reality  

Microsoft Academic Search

In the past few years, corporate governance has become a popular area of discussion in continental Europe. Having been a topic of academic research for a long time in the Anglo-Saxon literature, corporate governance has only recently moved from a special interest into all sections of the corporate sector and the political scene. For example, the recent publication of the

Wolfgang Drobetz

2002-01-01

446

Corporate wiki users: results of a survey  

Microsoft Academic Search

A survey of 168 corporate wiki users was conducted. Findings indicate that corporate wikis appear to be sustainable. Users stated three main types of benefits from corporate wikis: enhanced reputation, work made easier, and helping the organization to improve its processes. These benefits were seen as more likely when the wiki was used for tasks requiring novel solutions and the

Ann Majchrzak; Christian Wagner; Dave Yates

2006-01-01

447

DOW CORNING CORPORATION Material Safety Data Sheet  

E-print Network

DOW CORNING CORPORATION Material Safety Data Sheet Page: 1 of 8 Version: 1.0 Revision Date: 2005/Repeated Exposure Effects #12;DOW CORNING CORPORATION Material Safety Data Sheet Page: 2 of 8 Version: 1.0 Revision to keep fire exposed containers cool. #12;DOW CORNING CORPORATION Material Safety Data Sheet Page: 3 of 8

Garmestani, Hamid

448

47 CFR 90.185 - Multiple licensing of radio transmitting equipment in the mobile radio service.  

Code of Federal Regulations, 2013 CFR

...of radio transmitting equipment in the mobile radio service. 90.185 Section 90...SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Policies Governing the...of radio transmitting equipment in the mobile radio service. Two or more...

2013-10-01

449

47 CFR 90.185 - Multiple licensing of radio transmitting equipment in the mobile radio service.  

Code of Federal Regulations, 2012 CFR

...of radio transmitting equipment in the mobile radio service. 90.185 Section 90...SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Policies Governing the...of radio transmitting equipment in the mobile radio service. Two or more...

2012-10-01

450

Optimization of Satellite Constellation Reconfiguration  

E-print Network

Optimization of Satellite Constellation Reconfiguration by Uriel Scialom Submitted Students #12;2 #12;Optimization of Satellite Constellation Reconfiguration by Uriel Scialom Submitted for the degree of Master of Science in Aeronautics and Astronautics Abstract Traditional satellite constellation

451

Data Collection Satellite Application in Precision Agriculture  

NASA Astrophysics Data System (ADS)

Agricultural Instrumentation Research Center, Brazilian Agricultural Research Corporation; Space Programs Brazil launched in 1993 its first satellite partially built and entirely designed, integrated, tested and operated in the country. It was the SCD-1 satellite, a small (115 kg. and an octagonal prism with 80 cm. height and an external diameter of 100 cm.) with a payload transponder that receives data from ground platforms spread all over the country (including its sea shore). These data are then retransmitted to a receiving station at every satellite pass. Data collected and received are processed at Data Collection Mission Center for distribution via internet at most 30 min after the satellite pass. The ground platforms are called PCD's and differ in the parameters measured according to its purpose and location. Thus, they are able to measure temperature, rain level, wind direction, solar radiation, carbon monoxide as well as many others, beyond its own location. SCD- 1 had a nominal designed life of one year, but is still functioning. It is a LEO satellite with inclination of 25. In 1998, the country launched SCD-2, with the same purpose, but in phase with SCD-1 . Other differences were a higher index of Brazilian made components and an active attitude control subsystem for the spin rate provided by the magnetic torque coils (these in accordance with a development strategy previously planned). In 1999 the country launched in cooperation with China a remote sensing satellite (mass of 1.4 ton.) called CBERS-1. This satellite is sun synchronous (98 inclination) and also carries a transponder for data collection/transmission as a secondary payload. Thus, the country has now three satellites with data collection/transmission capabilities, two in low inclination phased orbits and one in polar orbit, providing a nice coverage both geographical and temporal not only to its territory but also to other regions of the world.. At first there were not too many PCD's over Brazilian territory. There were 25 platforms when SCD-1 was launched. However this number is growing rapidly to 400 platforms, at first for measurements of water reservoir levels as well as other hydrology applications (The Brazilian Electricity Regulatory Agency - ANEEL is the customer), and for many other different applications such as meteorology, oceanography, environmental monitoring sciences, and people and animal tracking. The clear feeling is that users are discovering a satellite system whose benefits were not previously well understood when launched and being able to propose and come up with different and useful applications. A new field in the country that has a great potential to benefit from this system is agriculture. Per se, this is a very important sector of the Brazilian economy and its international trade. Combining it with space technology may justify the investment of new and low cost dedicated satellites. This paper describes a new proposal for use of the SCD-1,2,CBERS-1 satellite system for precision agriculture. New PCD's would be developed for measurements of chemical content of the soil, such as, for example, Nitrogen and others, beyond humidity and solar incidence. This can lead to a more efficient fertilization, harvesting and even the spray of chemical defensives, with the consequence of environment protection. The PCD's ground network so established, along with the information network already available, combined with the space segment of such a system may, as previously said, be able to justify the investment in low cost satellites with this sole purpose.

Duro, O.

2002-01-01

452

Satellite-aided mobile communications, experiments, applications and prospects  

NASA Technical Reports Server (NTRS)

NASA's ATS-series of satellites were used in a series of communications and position fixing experiments with automotive vehicles, ships and aircraft. Applications of the communications were demonstrated and evaluated for public services including law enforcement, search and rescue, and medical emergency, and for commercial uses in the land and maritime transportation industries. The technical success of the experiments and the demonstrated potential value of the communications prompted a study that concluded an operational satellite-aided system would be a valuable augmentation of planned trunking or cellular type terrestrial mobile radio telephone systems.

Anderson, R. E.; Frey, R. L.; Lewis, J. R.; Milton, R. T.

1980-01-01

453

AB Levitrons and their Applications to Earth's Motionless Satellites  

E-print Network

Author offers the new and distinctly revolutionary method of levitation in artificial magnetic field. It is shown that a very big space station and small satellites may be suspended over the Earth's surface and used as motionless radio-TV translators, telecommunication boosters, absolute geographic position locators, personal and mass entertainment and as planet-observation platforms. Presented here is the theory of big AB artificial magnetic field and levitation in it is generally developed. Computation of three macro-projects: space station at altitude 100 km, TV-communication antenna at height 500 m, and multi-path magnetic highway. Key words: levitation, AB Levitrons, motionless space satellite.

Alexander Bolonkin

2007-08-18

454

Direct/community broadcast projects using space satellites  

NASA Technical Reports Server (NTRS)

A review is presented of direct/community broadcast projects which are currently in preparation in India, Canada, and Japan. It is shown that the satellite broadcast experiments involved are conducted for practical domestic reasons. The broadcast activities in all three projects will not reach other countries' TV receivers unless those countries take deliberate steps to enable themselves to receive such broadcasts. It is pointed out that for technological reasons problems of intrusion and interference connected with the use of satellites in broadcast operations may be much easier to handle than similar problems related to conventional radio broadcasting.

Frutkin, A. W.

1975-01-01

455

MEMOS - Mars Environment Monitoring Satellite  

NASA Astrophysics Data System (ADS)

The Swedish Institute of Space Physics (IRF) in cooperation with the Swedish Space Corporation (SSC) has conducted first studies on a Mars Environment Monitoring Satellite (MEMOS). The MEMOS microsatellite (mass < 20 kg) will accommodate four scientific instruments: solar EUV/UV monitor (SEM), solar wind monitor (SWIM), magnetometer (MAG) and radiation environment monitor (REM). The payload monitors the solar conditions at Mars and characterizes the Mars environment to support other missions and science investigations. Monitoring of the solar wind parameters (velocity, density, and field) is the key for any aeronomy and solar wind interaction mission at Mars. The solar EUV / UV (HeII 30.4 nm and HII 121.6 nm) flux monitoring is required for upper atmosphere / ionosphere studies. The radiation environment monitoring is needed to study space weather effects on the near-Mars environment as well as for the preparations for man-flights. MEMOS follows the design philosophy of a detached and autonomously flying instrument for achieving the mentioned objectives. It is intended to be carried "piggy-back" to Mars on a suitable mission. Potential missions are: ESA Mars orbiters within the NEXT or Cosmic Vision programs, NASA Mars orbiters, national / bilateral Mars missions. At Mars MEMOS is separated from its carrier (parent satellite) via the release mechanism implemented in the dual formation flight mission PRISMA. The separation will take place during the orbit insertion scenario of the parent satellite at Mars thus placing MEMOS in a highly elliptical orbit guarantying sufficient observation time in the solar wind. In orbit MEMOS will autonomously detumble and spin-up to ~1 rpm for reasons of stabilization and to fulfill instrument requirements. Such a low spin-rate is sufficient for a required inertial pointing accuracy of 2.5 because of the small external disturbance torques (< 10-7 Nm) predominant at Mars responsible for nutation and precession of the spin-axis. The advances in micropropulsion systems providing ?NmN adjustable thrust levels and reducing the dry mass to ~2 kg respectively are key factors in keeping the microsatellite stabilized and sun-pointed without stressing the mass budget. The low thrust level enables precise and active nutation damping. Moreover the system offers the possibility of implementing active orbit control or formation flight demonstrations at Mars. Attitude will be determined on-board with an accuracy < 1.0 using miniaturized Horizon Crossing Indicators, a two-axis sun sensor and in support accelerometers and gyroscopes based on MEMS-technology. TM/TC will be relayed via the parent satellite in the UHF frequency range. Therefore the Electra Lite (ELT) Proximity-1 transceiver will autonomously communicate with the parent satellite at inter-satellite ranges < 10 000 km featuring adaptive bit rates > 2 kbit/s. The transceiver also implements a coherent transponding mode for orbit determination through two-way Doppler ranging between the parent satellite and MEMOS. In addition ELT is compatible with a future Martian communication and navigation network pursued by NASA, which could be taken advantage of in the future for relaying data or performing ranging via other satellites part of the network. A system design driver for inter-satellite communication at Mars is the high demand of power. This leads to a disk-shape and thus easy to accommodate spacecraft configuration of MEMOS comprising a single sun-pointing solar array favourable in terms of power and spin stability. Multi-junction solar cells, which currently have an efficiency of ~29% under laboratory conditions are a key factor to keep MEMOS solar array area of ~1.15 m2 small compared to the worst case system power requirements of ~105 W. During eclipse periods high-efficient Li-ion batteries (6 x 20 Wh) will ensure power supply. The spacecraft and payload design will incorporate new technology developments such as autonomous navigation, MicroElectroMechanical Systems MEMS, Micro- Opto-ElectroMechanical Sys

Ott, T.; Barabash, S.; von Schele, F.; Clacey, E.; Pokrupa, N.

2007-08-01

456

National Radio Astronomy Observatory The radio emission (orange) detected  

E-print Network

NRAO National Radio Astronomy Observatory #12;The radio emission (orange) detected by the NRAO Very located in New Mexico. The National Radio Astronomy Observatory (NRAO) enables cutting-edge research in the study of the Universe using radio astronomy techniques, attracts and trains future scientists

Groppi, Christopher

457

OneWorldRadio  

NSDL National Science Digital Library

A number of media commentators have been complaining lately about the lack of ideological viewpoints within the vast sea of radio programming, something that has not been lost on the people at OneWorldRadio. Funded by the Department for International Development, OneWorld Radio is part of an international network of over 1200 partner organizations that are utilizing the internet "to promote human rights and sustainable development worldwide." With online audio content from member organizations (such as radio stations) available in French, Spanish, and a number of other languages, visitors can listen or download any one of hundreds of programs archived here. Additionally, visitors can elect to search their impressive archive by language, region, or topic. Persons interested in the use of radio for development and human rights will want to examine the news and events section as it contains important updates about events dealing with conferences on media freedom throughout the world and links to important radio broadcasts of note. Finally, visitors (and all who sign up for the free membership) can elect to receive the helpful OneWorldRadio e-newsletter.

458

Experimental and theoretical analysis of the ionospheric impact on the amplitude and phase oscillations of GPS signals in the satellite-to-satellite and satellite-to ground communication links  

NASA Astrophysics Data System (ADS)

By using the CHAllenge Minisatellite Payload (CHAMP) radio occultation (RO) data, a description of different types of the ionospheric impacts on the RO signals at the altitudes 30-90 km of the RO ray perigee is given and compared with the results of measurements obtained earlier in the satellite-to-Earth communication link at frequency 1.5415 GHz. An analytical model is introduced for describing propagation of radio waves in a stratified medium consisting of sectors with spherically symmetric refractivity distribution. This model gives analytical expressions for the phase delay, eikonal, bending angle, and refractive attenuation of radio waves given and is applied to the analysis of radio wave propagation phenomena along an extended path including the atmosphere and two parts of the ionosphere. Analytical model can be used for analytical ray tracing. Analytical ray tracing can control different regimes of the GPS signal propagation (multipath, diffraction, waveguide, etc.) and can be performed in general case for the analysis of radio communication and GPS navigation in trans-ionospheric links (satellite-to-satellite, satellite-to-Earth).The model explains significant amplitude and phase variations at altitudes 30-90 km of the RO ray perigee and attributes them to inclined ionospheric layers. Based on this analytical model, an innovative technique is introduced to locate layers in the atmosphere and ionosphere. A necessary and sufficient criterion is obtained for a layer to be located at the radio occultation (RO) ray perigee. The displacement of an ionospheric or atmospheric layer from the RO ray perigee can be assessed both, qualitatively and quantitatively using this criterion. The new criterion opens a new avenue in terms of measuring the altitude and slope of the atmospheric and ionospheric layers. The new criterion provides an improved estimation of the altitude and location of the ionospheric plasma layers compared with the back-propagation radio-holographic method previously used. The work is partly supported by RFBR grant No. 10-02-01015-a.

Pavelyev, A. G.; Zhang, K.; Liou, Y.; Wang, C.; Wickert, J.; Schmidt, T.; Pavelyev, A. A.; Kuleshov, Yu.

2012-04-01

459

NASARC - NUMERICAL ARC SEGMENTATION ALGORITHM FOR A RADIO CONFERENCE  

NASA Technical Reports Server (NTRS)

NASARC was developed from the general planning principles and decisions of both sessions of the World Administrative Radio Conference on the Use of the Geostationary Satellite Orbit and on the Planning of Space Services Utilizing It (WARC-85, WARC-88). NASARC was written to help countries satisfy requirements for nation-wide Fixed Satellite services from at least one orbital position within a predetermined arc. The NASARC-generated predetermined arcs are each based on a common arc segment visible to a group of compatible service areas, and provide a means of generating a highly flexible allotment plan with a reduced need for coordination among administrations. The selection of particular groupings of service areas and their associated predetermined arcs is made according to a heuristic approach using several figures of merit designed to confront the most difficult allotment problems. NASARC attempts to select groupings and predetermined arc sizes so that the requirements of all administrations are met before the available orbital arc is exhausted. The predetermined arcs allow considerable freedom of choice in the positioning of space stations for all members of any grouping. The approach to allotment planning for which NASARC was designed consists of two phases. The first is the use of NASARC to identify predetermined arc segments common to groups of administrations. Those administrations within a group and sharing a common predetermined arc segment would be able to position their individual space stations at any one of a number of orbital positions within the predetermined arc. The second phase involves the use of a plan synthesis program (such as the ORBIT program resident at the International Frequency Registration Board in Geneva, Switzerland) to identify example scenarios of specific space station placements. NASARC software is modular, and consists of several programs to be run in sequence. The grouping module, NASARC1, identifies compatible groups of several service areas that are sufficiently separated geographically so that co-location or near co-location of their space stations will permit a user-specified downlink performance criterion to be satisfied. Pairwise compatibility between systems is assessed on the basis of the satellite separation required to meet this criterion. NASARC2 examines all groups of compatible administrations with their corresponding arc segments and computes a common predetermined arc. After an orbital slot of sufficient size has been found, NASARC2 calculates the required orbital separation between the critical group and its potential east and west neighbors and determines predetermined arc placement accordingly. NASARC3 updates and extends the feasible orbital locations for predetermined arcs associated with compatible groups of service areas to provide flexibility for rearrangement if necessary. NASARC4 performs rearrangement of predetermined arc segments where rearrangement will provide increased total arc available for subsequent placement of additional predetermined arcs and produces the final output report of the NASARC package. In addition to planning assumed homogeneous systems, NASARC can take into account such factors as rain attenuation, individual antenna parameters, power calculation options, minimum power values, different required carrier-to-interface ratios, variable grouping criteria, and affiliated sets of service areas. The modules allow the baseline assumptions to be modified, some on an individual service area basis. NASARC array dimensions have been structured to fit within the currently available 12MB memory capacity of the International Frequency Registration Board computer facility. NASARC was written in ANSI standard FORTRAN 77 and developed on an AMDAHL 5860 running under the IBM VM operating system. The package requires 8.1MB of central memory. NASARC (version 4.0) was written in 1988. IBM and VM are registered trademarks of International Business Machines. AMDAHL 5860 is a trademark of Amdahl Corporation.

Whyte, W. A.

1994-01-01

460

Transit satellite system timing capabilities  

NASA Technical Reports Server (NTRS)

Current time transfer capabilities of the Transit Satellite System are reviewed. Potential improvements in the changes in equipment and operational procedures using operational satellites are discussed.

Finsod, T. D.

1978-01-01

461

Satellite Breakup Risk Mitigation  

NASA Technical Reports Server (NTRS)

Many satellite breakups occur as a result of an explosion of stored energy on-board spacecraft or rocket-bodies. These breakups generate a cloud of tens or possibly hundreds of thousands of debris fragments which may pose a transient elevated threat to spaceflight crews and vehicles. Satellite breakups pose a unique threat because the majority of the debris fragments are too small to be tracked from the ground. The United States Human Spaceflight Program is currently implementing a risk mitigation strategy that includes modeling breakup events, establishing action thresholds, and prescribing corresponding mitigation actions in response to satellite breakups.

Leleux, Darrin P.; Smith, Jason T.

2006-01-01

462

Satellite selection criteria  

NASA Technical Reports Server (NTRS)

An attempt is made to give relative weight to the factors which influence the selection of satellites for inclusion in the gravity modeling problem associated with TOPEX. This scheme gives both credits and demerits in this process and does so in a relative sense stressing characteristics which are most important while factoring in the major problems associated with some satellites. Selection factors include a data value assessment, uniqueness of orbital characteristics, satellite similarity to TOPEX sensitivities, apsidal coverage, nonconservative force influences, and sensitivity to the anomalous field.

Klosko, S. M.; Lerch, F. J.; Wagner, C. A.; Colombo, O. L.

1985-01-01

463

Television satellite programs  

NASA Astrophysics Data System (ADS)

Why and how satellite television transmission is being done, especially TDF-1/TV-Sat, are considered. The need for satellite television is assessed in terms of extending areas of reception. Problems of optimal signal strength, installation cost, and spillover are assessed. Political, cultural, and commercial aspects are also covered. Diverse satellite television systems to date are compared. The TDF-1/TV-Sat program is outlined as a practical application of what until now has been only experimental. System characteristics and its modular design are shown. Possible uses beyond television (teletex; viewdata; videotext) are speculated on.

Usunier, P.

464

Advanced communications satellite systems  

NASA Technical Reports Server (NTRS)

There is a rapidly growing demand for satellite circuits, particularly for domestic service within the U.S. NASA's current program is aimed at developing the high risk, advanced satellite communications technologies required to significantly increase the capacity of future satellite communications systems. Attention is given to aspects of traffic distribution and service scenario, problems related to effects of rain attenuation, details regarding system configuration, a 30/20 GHz technology development approach, an experimental flight system, the communications payload for the experimental flight system, a typical experiment flight system coverage, and a typical three axis stabilized flight spacecraft.

Sivo, J. N.

1983-01-01

465

Positions of Uranian satellites.  

NASA Astrophysics Data System (ADS)

Positions of Uranian satellites from 333 photographic plates obtained at the Cassegrain focus of a 1.6 m reflector are given for the oppositions of 1983 through 1988. These positions were reduced using photometric methods and compared with those calculated theoretically calculated from GUST86. The observed minus calculated residuals referred to Oberon, have standard deviations of the order of 0".04 for the four greatest Uranian satellites and 0".09 for Miranda. These residuals for the four satellites are better than the most precise found in the literature.

Veiga, C. H.; Vieira Martins, R.

1994-11-01

466

Operation Argus. Satellite measurements  

SciTech Connect

Following a theory on the trapping of electrons from nuclear explosions by the magnetic field of the earth, DOD initiated Operation Argus in May 1958 to provide an experimental check of the theory. Nuclear devices were detonated at great altitudes, and the ensuing effects were measured by instrumented satellites, rocket probes, and land and sea observation stations in various parts of the world. This report describes the Argus Satellite Project, the broad theory of the Christofilos effect, the measurements of the background radiation, and the measurement of the effect itself. After each Argus nuclear detonation, the instrumented satellite reported a new and well-defined radiation belt that persisted before many hours.

Kostoff, P.C.; Stuhlinger, E.; Kampneier, H.W.; Boehm, J.

1984-08-31

467

Skeletal muscle satellite cells  

NASA Technical Reports Server (NTRS)

Evidence now suggests that satellite cells constitute a class of myogenic cells that differ distinctly from other embryonic myoblasts. Satellite cells arise from somites and first appear as a distinct myoblast type well before birth. Satellite cells from different muscles cannot be functionally distinguished from one another and are able to provide nuclei to all fibers without regard to phenotype. Thus, it is difficult to ascribe any significant function to establishing or stabilizing fiber type, even during regeneration. Within a muscle, satellite cells exhibit marked heterogeneity with respect to their proliferative behavior. The satellite cell population on a fiber can be partitioned into those that function as stem cells and those which are readily available for fusion. Recent studies have shown that the cells are not simply spindle shaped, but are very diverse in their morphology and have multiple branches emanating from the poles of the cells. This finding is consistent with other studies indicating that the cells have the capacity for extensive migration within, and perhaps between, muscles. Complexity of cell shape usually reflects increased cytoplasmic volume and organelles including a well developed Golgi, and is usually associated with growing postnatal muscle or muscles undergoing some form of induced adaptive change or repair. The appearance of activated satellite cells suggests some function of the cells in the adaptive process through elaboration and secretion of a product. Significant advances have been made in determining the potential secretion products that satellite cells make. The manner in which satellite cell proliferative and fusion behavior is controlled has also been studied. There seems to be little doubt that cellcell coupling is not how satellite cells and myofibers communicate. Rather satellite cell regulation is through a number of potential growth factors that arise from a number of sources. Critical to the understanding of this form of control is to determine which of the many growth factors that can alter satellite cell behavior in vitro are at work in vivo. Little work has been done to determine what controls are at work after a regeneration response has been initiated. It seems likely that, after injury, growth factors are liberated through proteolytic activity and initiate an activation process whereby cells enter into a proliferative phase. After myofibers are formed, it also seems likely that satellite cell behavior is regulated through diffusible factors arising from the fibers rather than continuous control by circulating factors.(ABSTRACT TRUNCATED AT 400 WORDS).

Schultz, E.; McCormick, K. M.

1994-01-01

468

Videoconferencing services via satellite  

NASA Astrophysics Data System (ADS)

Videoconferencing services in general are discussed with special attention being given to satellite use. The always increasing internationalization of professional activities stimulates the demand for novel and flexible communication media. Videoconferencing is such a promising medium, for which the technology is rapidly maturing. An introductory analysis of human to human communication and its practical problems is presented, as a framework for deriving generic user requirements. The subject of videoconferencing services via satellite is approached both from the user's and from the service provider's perspective. A practical implementation of a videoconferencing network via satellite is described.

Desonville, E.

1991-10-01

469

ASAP- ARTIFICIAL SATELLITE ANALYSIS PROGRAM  

NASA Technical Reports Server (NTRS)

The Artificial Satellite Analysis Program (ASAP) is a general orbit prediction program which incorporates sufficient orbit modeling accuracy for mission design, maneuver analysis, and mission planning. ASAP is suitable for studying planetary orbit missions with spacecraft trajectories of reconnaissance (flyby) and exploratory (mapping) nature. Sample data is included for a geosynchronous station drift cycle study, a Venus radar mapping strategy, a frozen orbit about Mars, and a repeat ground trace orbit. ASAP uses Cowell's method in the numerical integration of the equations of motion. The orbital mechanics calculation contains perturbations due to non-sphericity (up to a 40 X 40 field) of the planet, lunar and solar effects, and drag and solar radiation pressure. An 8th order Runge-Kutta integration scheme with variable step size control is used for efficient propagation. The input includes the classical osculating elements, orbital elements of the sun relative to the planet, reference time and dates, drag coefficient, gravitational constants, and planet radius, rotation rate, etc. The printed output contains Cartesian coordinates, velocity, equinoctial elements, and classical elements for each time step or event step. At each step, selected output is added to a plot file. The ASAP package includes a program for sorting this plot file. LOTUS 1-2-3 is used in the supplied examples to graph the results, but any graphics software package could be used to process the plot file. ASAP is not written to be mission-specific. Instead, it is intended to be used for most planetary orbiting missions. As a consequence, the user has to have some basic understanding of orbital mechanics to provide the correct input and interpret the subsequent output. ASAP is written in FORTRAN 77 for batch execution and has been implemented on an IBM PC compatible computer operating under MS-DOS. The ASAP package requires a math coprocessor and a minimum of 256K RAM. This program was last updated in 1988 with version 2.03. IBM PC is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation. Lotus and 1-2-3 are registered trademarks of Lotus Development Corporation.

Kwok, J.

1994-01-01

470

Riding the Radio Waves  

NSDL National Science Digital Library

Students learn how AM radios work through basic concepts about waves and magnetic fields. Waves are first introduced by establishing the difference between transverse and longitudinal waves, as well as identifying the amplitude and frequency of given waveforms. Then students learn general concepts about magnetic fields, leading into how radio waves are created and transmitted. Several demonstrations are performed to help students better understand these concepts. This prepares students to be able to comprehend the functionig of the AM radios they will build during the associated activity.

Techtronics Program,

471

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

USGS Publications Warehouse

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.

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

2003-01-01

472

Astronaut Ron Parise checks timeline for monitoring Jupiter and its satellites  

NASA Technical Reports Server (NTRS)

Astronaut Ronald A. Parise, STS-67 payload specialist and a senior scientist in the Space Observatories Department of Computer Sciences Corporation (CSC), checks a timeline for monitoring of Jupiter and its satellites. Parise is on the aft flight deck of the Earth-orbiting Space Shuttle Endeavour.

1995-01-01

473

OPENENDED CONFIGURATIONS OF RADIO TELESCOPES  

E-print Network

OPEN­ENDED CONFIGURATIONS OF RADIO TELESCOPES: A GEOMETRICAL ANALYSIS Vladik Kreinovich, Scott A. The quality of radio astronomical images drastically depends on where we place the radio telescopes. During a theoretical justification for this empirical fact. Why radio telescopes. According to modern physics, most

Kreinovich, Vladik

474

Biological satellite Kosmos-936  

NASA Technical Reports Server (NTRS)

A description is given of physiological experiments performed on the biological satellite Kosmos-936. Other experiments to determine the electrostatic and dielectric responses to the effects of cosmic radiation are discussed.

Vedeshin, L. A.

1978-01-01

475

Communication satellite antennas  

Microsoft Academic Search

During the previous two decades, communication satellites have developed from the pioneering Telstar to the highly sophisticated ATS-6. Concurrrently, the spacecraft antennas have developed from a low-gain \\

LEON J. RICARDI

1977-01-01

476

Civil satellite navigation systems  

NASA Astrophysics Data System (ADS)

The use of satellite navigation for civil purposes is examined critically to compare the merits and costs of existing and practical satellite systems. Accuracy and range considerations are reviewed, and the basic requirements of radionavigation systems are set forth. Specific data are given regarding coverage area, integration with ground-based systems, monitoring and control, and accuracy. Systems reviewed include 'Starfix,' Inmarsat, EVA Vavsat, and Geostar/Locstar/Omnitracs, and extensive illustrations are provided to demonstrate constellation geometries. When in view, two or three geosynchronous satellites can provide acceptable fixing, and 9 satellites can provide global coverage. It is argued that systems such as 'Starfix' are commercially viable with less than 100 users, and Inmarsat is identified as an effective European civil system.

Blanchard, Walter F.

1991-07-01

477

Meteorological satellite accomplishments  

NASA Technical Reports Server (NTRS)

The various types of meteorological satellites are enumerated. Vertical sounding, parameter extraction technique, and both macroscale and mesoscale meteorological phenomena are discussed. The heat budget of the earth-atmosphere system is considered, along with ocean surface and hydrology.

Allison, L. J.; Arking, A.; Bandeen, W. R.; Shenk, W. E.; Wexler, R.

1974-01-01

478

AUSSAT mobile satellite services  

NASA Technical Reports Server (NTRS)

An overview of AUSSAT's planned mobile satellite system is given. The development program which is being undertaken to achieve the 1992 service date is described. Both business and technical aspects of the development program are addressed.

Nowland, Wayne L.; Wagg, Michael; Simpson, Daniel

1988-01-01

479

Sea Turtle Satellite Tracking  

NSDL National Science Digital Library

Near real-time tool for collecting, managing and sharing marine life satellite tracking data. Over 30 projects in US, Caribbean, Mediterranean, Indo-Pacific, and Australian waters. Provides links to background information for each project, the animals they are tracking, and maps that are updated regularly. Teaching resources include maps for tracking, suggestions for using data in lessons on geography, biology, earth science, math. Good introduction to satellite telemetry methodology and applications.

480

Satellite battery testing status  

NASA Technical Reports Server (NTRS)

Because of the large numbers of satellite cells currently being tested and anticipated at the Naval Weapons Support Center (NAVWPNSUPPCEN) Crane, Indiana, satellite cell testing is being integrated into the Battery Test Automation Project (BTAP). The BTAP, designed to meet the growing needs for battery testing at the NAVWPNSUPPCEN Crane, will consist of several Automated Test Stations (ATSs) which monitor batteries under test. Each ATS will interface with an Automation Network Controller (ANC) which will collect test data for reduction.

Haag, R.; Hall, S.

1986-01-01

481

Launching a Satellite  

NSDL National Science Digital Library

Isaac Newtons famous thought experiment about what would happen if you launched a cannon from a mountaintop at a high velocity comes to life with an interactive computer model. You are charged with the task of launching a satellite into space. Control the angle and speed at which the satellite is launched, and see the results to gain a basic understanding of escape velocity.

Consortium, The C.

2011-12-11

482

GUST86 - An analytical ephemeris of the Uranian satellites. [General Uranus Satellite Theory  

NASA Technical Reports Server (NTRS)

The General Uranus Satellite Theory GUST (Laskar, 1986) is used for the construction of an analytical ephemeris for the Uranian satellites. The theory is fitted against earth-based observations from 1911 to 1986, and all radio and optical data obtained during Voyager encounter with Uranus. Earth-based observations alone allow the determination of masses which are within 15 percent of the values determined by the Uranus flyby. The analysis of all the observations confirm the values of the masses obtained during the encounter (Stone and Miner, 1986) and give a complete set of dynamical parameters for the analytical theory. An analytical ephemeris, GUST86, with an estimated precision of about 100 km with respect to Uranus is obtained.

Laskar, J.; Jacobson, R. A.

1987-01-01

483

Modulation/demodulation techniques for satellite communications. Part 1: Background  

NASA Technical Reports Server (NTRS)

Basic characteristics of digital data transmission systems described include the physical communication links, the notion of bandwidth, FCC regulations, and performance measurements such as bit rates, bit error probabilities, throughputs, and delays. The error probability performance and spectral characteristics of various modulation/demodulation techniques commonly used or proposed for use in radio and satellite communication links are summarized. Forward error correction with block or convolutional codes is also discussed along with the important coding parameter, channel cutoff rate.

Omura, J. K.; Simon, M. K.

1981-01-01

484

Eratosthenes via Ham Radio  

ERIC Educational Resources Information Center

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

Koser, John F.

1975-01-01

485

Radio Emissions At Mercury  

NASA Astrophysics Data System (ADS)

Mercury may produce cyclotron radio emissions (up to~10-20 kHz) from mildly ener- getic electrons in its most highly magnetized (polar) regions, and possible synchrotron radiation (up to a few MHz?) from more energetic electrons. Cyclotron emissions would be trapped in the magnetospheric cavity, and we attempt to estimate their in- tensity by extrapolating a scaling law established for the other solar system plane- tary radio emissions. In paralel, solar radio emissions (from interplanetary transient shocks, CMEs, and energetic particle streams) observed in the vicinity of Mercury could be a good index of solar activity, to be correlated with the Hemrean magne- tospheric response. We summarize the experimental requirements corresponding to these scientific objectives and present a possible contribution to a Radio and Plasma Wave Electric-field (RPW-E) instrument on BepiColombo/MMO.

Zarka, P.; Bougeret, J.-L.; Issautier, K.; Maksimovic, M.; Manning, R.; Meyer, N.; Moncuquet, M.

486

Radio frequency pressure transducer  

Microsoft Academic Search

A novel system is reported here for the pressure measurement at microwave and millimetre-wave frequencies. This method consists in using a radio frequency transducer based on RF resonator. Accurate determination of the pressure is expected.

M. M. Jatlaoui; P. Pons; H. Aubert

2007-01-01

487

The Sardinia Radio Telescope  

NASA Astrophysics Data System (ADS)

We present the status of the Sardinia Radio Telescope (SRT) project, a new general purpose, fully steerable 64 m diameter parabolic radio telescope under construction in Sardinia. The instrument is funded by Italian Ministry of University and Research (MIUR), by the Sardinia Regional Government (RAS), and by the Italian Space Agency (ASI), and it is charge to three research structures of the National Institute for Astrophysics (INAF): the Institute of Radio Astronomy of Bologna, the Cagliari Astronomical Observatory (in Sardinia), and the Arcetri Astrophysical Observatory in Florence. The radio telescope has a shaped Gregorian optical configuration with a 8 m diameter secondary mirror and additional Beam-Wave Guide (BWG) mirrors. One of the most challenging feature of SRT is the active surface of the primary reflector which provides good efficiency up to about 100 GHz. This paper reports on the most recent advances of the construction.

D'Amico, Nichi

2011-08-01

488

The satellites of Uranus  

NASA Technical Reports Server (NTRS)

Observations and the probable natures of the five known satellites of Uranus are reviewed. Photographic, photoelectric and CCD photometry of the satellites since 1961, although in agreement within experimental error, is not as mutually consistent as may be expected, and broadband JHK photometry falls in a portion of the J-H, H-K color diagram difficult to interpret. Spectrophotometry in the range 0.3-1.1 microns taken on two separate occasions is inconsistent, with only the relatively neutral reflectances of Titania and Oberon regarded as well established. Near-infrared spectrophotometry has revealed the presence of water ice or frost on the satellite surfaces, possibly in a very pure state, with spectra most similar to Ganymede. Estimations of the properties of the satellites from their surface geometric albedos, assumed mean densities and dynamics yield radii in the range 160-520 km, albedos on the order of 0.5 and densities of about 1.3 g/cu cm, similar to the icy Saturn satellites. The satellites are also believed to have formed after the event that caused the planet to tilt to its present obliquity.

Cruikshank, D. P.

1982-01-01

489

Neptune's small inner satellites  

NASA Astrophysics Data System (ADS)

Voyager 2 images revealed six small satellites orbiting within five planetary radii of Neptune. The largest, Proteus (1989N1), has a mean radius of 208 8 km; the smallest, Naiad (1989N6), is 29 6 km in radius. The four satellites for which reasonable radius measurements can be made all have geometric albedos (not accounting for opposition effects) of 0.06 at 0.48 pm. The albedos and phase coefficients of these satellites are very similar to those measured for the inner satellites of Uranus but are quite distinct from the values for Nereid (p = 0.16-0.20, ? = 0.028 magnitude/degree) as determined by Thomas et al. (this issue). Color measurements (0.4 to 0.6 ?m) of Proteus show a neutral color. The two largest satellites are resolved as irregular objects and have limb roughnesses comparable to those of similar-sized satellites of other planets. One image of Proteus shows a 150-km crater with some overlapping smaller craters; this feature allows measurement of a rotation rate consistent with a synchronous period. The irregular shape and heavily cratered, photometrically bland surface of Proteus are consistent with characteristics of a primitive, undifferentiated object. Evidently, Proteus has escaped the tidal heating believed to have been responsible for the remarkable geologic processes on the similar-sized bodies Miranda and Enceladus and perhaps Mimas.

Thomas, P.; Veverka, J.

490

Orbit determination accuracies using satellite-to-satellite tracking  

NASA Technical Reports Server (NTRS)

The uncertainty in relay satellite sate is a significant error source which cannot be ignored in the reduction of satellite-to-satellite tracking data. Based on simulations and real data reductions, it is numerically impractical to use simultaneous unconstrained solutions to determine both relay and user satellite epoch states. A Bayesian or least squares estimation technique with an a priori procedure is presented which permits the adjustment of relay satellite epoch state in the reduction of satellite-to-satellite tracking data without the numerical difficulties introduced by an ill-conditioned normal matrix.

Vonbun, F. O.; Argentiero, P. D.; Schmid, P. E.

1977-01-01

491

Corporate Headquarters Cisco Systems, Inc.  

E-print Network

Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 Cisco IP Phone 7961G/7961G-GE and 7941G/7941G-GE for Cisco CallManager 4.1(3) INCLUDING LICENSE AND WARRANTY Phone Guide #12;#12;Copyright © 2005 Cisco

Brody, James P.

492

Corporate Headquarters Cisco Systems, Inc.  

E-print Network

Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 Cisco uBR7100 Series and Cisco uBR7100E Series BY THIS REFERENCE. IF YOU ARE UNABLE TO LOCATE THE SOFTWARE LICENSE OR LIMITED WARRANTY, CONTACT YOUR CISCO

Westall, James M.

493

The Radio JOVE Project  

NASA Astrophysics Data System (ADS)

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

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

1999-09-01

494

Satellite-to-ground radiowave propagation - Theory, practice and system impact at frequencies above 1 GHz  

NASA Astrophysics Data System (ADS)

The effects of the earth atmosphere on radio waves traveling from GEO satellites to the ground are examined in a text which includes both introductory material suitable for undergraduate engineering students and detailed information and references for practicing radio engineers. Chapters are devoted to ionospheric effects; clean-air effects; attenuation effects; depolarization effects; terrain, multipath, and other particulate effects; and the restoration of performance during signal impairments. Extensive diagrams and graphs are provided.

Allnutt, Jeremy E.

495

Astrometry of southern radio sources  

NASA Technical Reports Server (NTRS)

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

White, Graeme L.; Jauncey, David L.; Harvey, Bruce R.; Savage, Ann; Gulkis, Samuel; Preston, Robert A.

1991-01-01

496

Silicon Satellites: Picosats, Nanosats, and Microsats  

NASA Technical Reports Server (NTRS)

Silicon, the most abundant solid element in the Earth's lithosphere, is a useful material for spacecraft construction. Silicon is stronger than stainless steel, has a thermal conductivity about half that of aluminum, is transparent to much of the infrared radiation spectrum, and can form a stable oxide. These unique properties enable silicon to become most of the mass of a satellite, it can simultaneously function as structure, heat transfer system, radiation shield, optics, and semiconductor substrate. Semiconductor batch-fabrication techniques can produce low-power digital circuits, low-power analog circuits, silicon-based radio frequency circuits, and micro-electromechanical systems (MEMS) such as thrusters and acceleration sensors on silicon substrates. By exploiting these fabrication techniques, it is possible to produce highly-integrated satellites for a number of applications. This paper analyzes the limitations of silicon satellites due to size. Picosatellites (approximately 1 gram mass), nanosatellites (about 1 kg mass), and highly capable microsatellites (about 10 kg mass) can perform various missions with lifetimes of a few days to greater than a decade.

Janson, Siegfried W.

1995-01-01

497

COMPASS Final Report: Lunar Relay Satellite (LRS)  

NASA Technical Reports Server (NTRS)

The Lunar Relay Satellite (LRS) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session was tasked to design a satellite to orbit in an elliptical lunar polar orbit to provide relay communications between lunar South Pole assets and the Earth. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The LRS is a half-TDRSS sized box spacecraft, which provides communications and navigation relay between lunar outposts (via Lunar Communications Terminals (LCT)) or Sortie parties (with user radios) and large ground antennas on Earth. The LRS consists of a spacecraft containing all the communications and avionics equipment designed by NASA Jet Propulsion Laboratory s (JPL) Team X to perform the relay between lunar-based assets and the Earth. The satellite design is a standard box truss spacecraft design with a thermal control system, 1.7 m solar arrays for 1 kWe power, a 1 m diameter Ka/S band dish which provides relay communications with the LCT, and a Q-band dish for communications to/from the Earth based assets. While JPL's Team X and Goddard Space Flight Center s (GSFC) I M Design Center (IMDC) have completed two other LRS designs, this NASA Glenn Research Center (GRC) COMPASS LRS design sits between them in terms of physical size and capabilities.

Oleson, Steven R.; McGuire, Melissa L.

2012-01-01

498

Satellite Delivery of Aviation Weather Data  

NASA Technical Reports Server (NTRS)

With aviation traffic continuing to increase worldwide, reducing the aviation accident rate and aviation schedule delays is of critical importance. In the United States, the National Aeronautics and Space Administration (NASA) has established the Aviation Safety Program and the Aviation System Capacity Program to develop and test new technologies to increase aviation safety and system capacity. Weather is a significant contributor to aviation accidents and schedule delays. The timely dissemination of weather information to decision makers in the aviation system, particularly to pilots, is essential in reducing system delays and weather related aviation accidents. The NASA Glenn Research Center is investigating improved methods of weather information dissemination through satellite broadcasting directly to aircraft. This paper describes an on-going cooperative research program with NASA, Rockwell Collins, WorldSpace, Jeppesen and American Airlines to evaluate the use of satellite digital audio radio service (SDARS) for low cost broadcast of aviation weather information, called Satellite Weather Information Service (SWIS). The description and results of the completed SWIS Phase 1 are presented, and the description of the on-going SWIS Phase 2 is given.

Kerczewski, Robert J.; Haendel, Richard

2001-01-01

499

Satellite Communications for ATM  

NASA Technical Reports Server (NTRS)

This presentation is an overview on Satellite Communication for the Aeronautical Telecommunication Management (ATM) research. Satellite Communications are being considered by the FAA and NASA as a possible alternative to the present and future ground systems supporting Air Traffic Communications. The international Civil Aviation Organization (ICAO) have in place Standards and Recommended Practices (SARPS) for the Aeronautical Mobile Satellite Services (AMSS) which is mainly derived from the pre-existing Inmarsat service that has been in service since the 1980s. The Working Group A of the Aeronautical Mobile Communication Panel of ICAO has also been investigating SARPS for what is called the Next Generation Satellite Service (NGSS) which conforms less to the Inmarsat based architecture and explores wider options in terms of satellite architectures. Several designs are being proposed by Firms such as Boeing, ESA, NASA that are geared toward full or secondary usage of satellite communications for ATM. Satellite communications for ATM can serve several purposes ranging from primary usage where ground services would play a minimal backup role, to an integrated solution where it will be used to cover services, or areas that are less likely to be supported by the proposed and existing ground infrastructure. Such Integrated roles can include usage of satellite communications for oceanic and remote land areas for example. It also can include relieving the capacity of the ground network by providing broadcast based services of Traffic Information Services messages (TIS-B), or Flight Information Services (FIS-B) which can take a significant portion of the ground system capacity. Additionally, satellite communication can play a backup role to support any needs for ground replacement, or additional needed capacity even after the new digital systems are in place. The additional bandwidth that can be provided via satellite communications can also open the door for many new applications that generally will enhance the standard services provided. All of those possibilities were investigated and comments, as well as descriptions of those analyses are put forward, as well as suggestions for future areas of study.

Shamma, Mohammed A.

2003-01-01

500

Requirements for a mobile communications satellite system. Volume 2: Technical report  

NASA Technical Reports Server (NTRS)

Three types of satellite aided mobile communications are considered for users in areas not served by (terrestrial) cellular radio systems. In system 1, mobile units are provided a direct satellite link to a gateway station, which serves as the interface to the terrestrial toll network. In system 2, a terrestrial radio link similar to those in cellular systems connects the mobile unit to a translator station; each translator relays the traffic from mobile units in its vicinity, via satellite, to the regional gateway. It is not feasible for system 2 to provide obiquitous coverage. Therefore, system 3 is introduced, in which the small percentage of users not within range of a translator are provided a direct satellite link as in system 1.

Horstein, M.

1983-01-01