Satellite Communications

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Satellite Communications. Arthur C Clarke wrote a seminal paper in 1945 in wireless world. Use three satellites in geo-synchronous orbit to enable intercontinental communications. System could be realised in '50 to 100 years'

Advances in Small Remotely Piloted Aircraft Communications and Remote Sensing in Maritime Environments including the Arctic

Science.gov (United States)

McGillivary, P. A.; Borges de Sousa, J.; Wackowski, S.; Walker, G.

2011-12-01

Small remotely piloted aircraft have recently been used for maritime remote sensing, including launch and retrieval operations from land, ships and sea ice. Such aircraft can also function to collect and communicate data from other ocean observing system platforms including moorings, tagged animals, drifters, autonomous surface vessels (ASVs), and autonomous underwater vessels (AUVs). The use of small remotely piloted aircraft (or UASs, unmanned aerial systems) with a combination of these capabilities will be required to monitor the vast areas of the open ocean, as well as in harsh high-latitude ecosystems. Indeed, these aircraft are a key component of planned high latitude maritime domain awareness environmental data collection capabilities, including use of visible, IR and hyperspectral sensors, as well as lidar, meteorological sensors, and interferometric synthetic aperture radars (ISARs). We here first describe at-sea demonstrations of improved reliability and bandwidth of communications from ocean sensors on autonomous underwater vehicles to autonomous surface vessels, and then via remotely piloted aircraft to shore, ships and manned aircraft using Delay and Disruption Tolerant (DTN) communication protocols. DTN enables data exchange in communications-challenged environments, such as remote regions of the ocean including high latitudes where low satellite angles and auroral disturbances can be problematic. DTN provides a network architecture and application interface structured around optionally-reliable asynchronous message forwarding, with limited expectations of end-to-end connectivity and node resources. This communications method enables aircraft and surface vessels to function as data mules to move data between physically disparate nodes. We provide examples of the uses of this communication protocol for environmental data collection and data distribution with a variety of different remotely piloted aircraft in a coastal ocean environment. Next, we

Satellite Communications

CERN Document Server

Pelton, Joseph N

2012-01-01

The field of satellite communications represents the world's largest space industry. Those who are interested in space need to understand the fundamentals of satellite communications, its technology, operation, business, economic, and regulatory aspects. This book explains all this along with key insights into the field's future growth trends and current strategic challenges. Fundamentals of Satellite Communications is a concise book that gives all of the key facts and figures as well as a strategic view of where this dynamic industry is going. Author Joseph N. Pelton, PhD, former Dean of the International Space University and former Director of Strategic Policy at Intelstat, presents a r

Cooperative measures to mitigate Asia-Pacific maritime conflicts.

Energy Technology Data Exchange (ETDEWEB)

Chai, Wen-Chung (Taiwan Navy)

2003-05-01

The economies of East Asia are predominantly export based and, therefore, place special emphasis on the security of the sea lines of communication (SLOCs). Due to economic globalization, the United States shares these concerns. Cooperative measures by the concerned parties could reduce the potential for disruption by maritime conflicts. Primary threats against the SLOCs are disputes over the resources under the seas, disputes over some small island groups, disputes between particular parties (China-Taiwan and North-South Korea), or illegal activities like smuggling, piracy, or terrorism. This paper provides an overview on these threats, issue by issue, to identify common elements and needed cooperation. Cooperation on other topics such as search and rescue, fisheries protection, and oil spill response may help support improved relations to prevent maritime conflicts. Many technologies can help support maritime cooperation, including improved communications links, tracking and emergency beacon devices, and satellite imaging. Appropriate technical and political means are suggested for each threat to the SLOCs.

Regional Maritime University Journal

African Journals Online (AJOL)

Maritime education and training; Maritime technology; Maritime administration; Maritime environmental and ocean management; Port and shipping administration; Maritime transport and logistics; Maritime policy and practices; Maritime safety and security; Engineering; Information Communication Technology; Oil and gas ...

Practising verbal maritime communication with computer dialogue systems using automatic speech recognition (My Practice session)

OpenAIRE

John, Peter; Wellmann, J.; Appell, J.E.

2016-01-01

This My Practice session presents a novel online tool for practising verbal communication in a maritime setting. It is based on low-fi ChatBot simulation exercises which employ computer-based dialogue systems. The ChatBot exercises are equipped with an automatic speech recognition engine specifically designed for maritime communication. The speech input and output functionality enables learners to communicate with the computer freely and spontaneously. The exercises replicate real communicati...

Satellite Communications for ATM

Science.gov (United States)

Shamma, Mohammed A.

2003-01-01

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

47 CFR 80.1133 - Transmission of safety communications.

Science.gov (United States)

2010-10-01

... SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating... safety traffic frequencies specified in § 80.1077, or via the maritime mobile satellite service or on... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transmission of safety communications. 80.1133...

A Dynamic Spectrum Allocation Algorithm for a Maritime Cognitive Radio Communication System Based on a Queuing Model

Directory of Open Access Journals (Sweden)

Jingbo Zhang

2017-09-01

Full Text Available With the rapid development of maritime digital communication, the demand for spectrum resources is increasing, and building a maritime cognitive radio communication system is an effective solution. In this paper, the problem of how to effectively allocate the spectrum for secondary users (SUs with different priorities in a maritime cognitive radio communication system is studied. According to the characteristics of a maritime cognitive radio and existing research about cognitive radio systems, this paper establishes a centralized maritime cognitive radio communication model and creates a simplified queuing model with two queues for the communication model. In the view of the behaviors of SUs and primary users (PUs, we propose a dynamic spectrum allocation (DSA algorithm based on the system status, and analyze it with a two-dimensional Markov chain. Simulation results show that, when different types of SUs have similar arrival rates, the algorithm can vary the priority factor according to the change of users’ status in the system, so as to adjust the channel allocation, decreasing system congestion. The improvement of the algorithm is about 7–26%, and the specific improvement is negatively correlated with the SU arrival rate.

Integrating small satellite communication in an autonomous vehicle network: A case for oceanography

Science.gov (United States)

Guerra, André G. C.; Ferreira, António Sérgio; Costa, Maria; Nodar-López, Diego; Aguado Agelet, Fernando

2018-04-01

Small satellites and autonomous vehicles have greatly evolved in the last few decades. Hundreds of small satellites have been launched with increasing functionalities, in the last few years. Likewise, numerous autonomous vehicles have been built, with decreasing costs and form-factor payloads. Here we focus on combining these two multifaceted assets in an incremental way, with an ultimate goal of alleviating the logistical expenses in remote oceanographic operations. The first goal is to create a highly reliable and constantly available communication link for a network of autonomous vehicles, taking advantage of the small satellite lower cost, with respect to conventional spacecraft, and its higher flexibility. We have developed a test platform as a proving ground for this network, by integrating a satellite software defined radio on an unmanned air vehicle, creating a system of systems, and several tests have been run successfully, over land. As soon as the satellite is fully operational, we will start to move towards a cooperative network of autonomous vehicles and small satellites, with application in maritime operations, both in-situ and remote sensing.

Trends in mobile satellite communication

Science.gov (United States)

Johannsen, Klaus G.; Bowles, Mike W.; Milliken, Samuel; Cherrette, Alan R.; Busche, Gregory C.

1993-01-01

Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make it clear that the trend in mobile satellite communication is toward more sophisticated satellites with a large number of spot beams and onboard processing, providing worldwide interconnectivity. Recent Hughes studies indicate that from a cost standpoint the geosynchronous satellite (GEOS) is most economical, followed by the medium earth orbit satellite (MEOS) and then by the low earth orbit satellite (LEOS). From a system performance standpoint, this evaluation may be in reverse order, depending on how the public will react to speech delay and collision. This paper discusses the trends and various mobile satellite constellations in satellite communication under investigation. It considers the effect of orbital altitude and modulation/multiple access on the link and spacecraft design.

Encryption protection for communication satellites

Science.gov (United States)

Sood, D. R.; Hoernig, O. W., Jr.

In connection with the growing importance of the commercial communication satellite systems and the introduction of new technological developments, users and operators of these systems become increasingly concerned with aspects of security. The user community is concerned with maintaining confidentiality and integrity of the information being transmitted over the satellite links, while the satellite operators are concerned about the safety of their assets in space. In response to these concerns, the commercial satellite operators are now taking steps to protect the communication information and the satellites. Thus, communication information is being protected by end-to-end encryption of the customer communication traffic. Attention is given to the selection of the NBS DES algorithm, the command protection systems, and the communication protection systems.

TD-LTE maritime trunking communication system based on TVWS

Science.gov (United States)

Ren, Chunxiang; Chen, Xing; Li, Wanchao; Chen, Baodan

2014-10-01

This paper collects the measurement results of 470 MHZ-960MHZ spectrum in the coastal areas, and analyzes the characteristics of TV broadcast spectrum occupancy in the measurement region. Moreover, this article proposes construct the TD-LTE maritime trunking communication system using geolocation database, television database (TVDB) and cognitive radio (CR) technology.

Maritime Work and Communication

Directory of Open Access Journals (Sweden)

Peter Andersen

2001-05-01

Full Text Available This paper presents findings from the project "Elastic Systems" under the Danish Center for Human Machine Interaction. The project aims at developing methods for analyzing dynamic maritime work processes and for designing flexible instrument interfaces that will support changing work environments. Here I only address the former issue, the design issues being published elsewhere, e.g. in Andersen(1999 and Andersen & May (2001. More data can be found in Andersen(2000. The purpose of the present paper is twofold: (1 to present characteristics of maritime work and communication, and (2 to suggest a conceptual framework that covers communicative as well as non-communicative acts. The latter purpose is motivated in two ways. Theoretical motivation: we know that language is self-referential, so that it can speak of non-linguistic entities like ships and waves as well as its own properties, such as the correct wording or style. The easiest way to accomplish this is for language to treat both domains in a similar way. The other motivation is more practical: it is a fact that communication and physical actions are interwoven in maritime work, and a theory that builds on a sharp distinction between these two kinds of behaviors will miss this basic characteristic. The data is from a voyage aboard Sally Maersk from Algeciras to Goteborg and back to Rotterdam. We recorded 60 hours of high quality video, and the paper builds upon a 16 hours trip from Felixstowe to Rotterdam, supplemented by data from simulated voyages in the simulator at the Danish Maritime Institute. The conceptual framework is based on Lind 1994 and Lind 2000 and distinguishes between the following types of action types: (1 Prevent(suppress, avoid: if I hadn't done it, then an undesirable state would have developed. Prevent drifting by using auxiliary rudder. (2 Maintain: if I hadn't done it, then a desirable state would have disappeared. Maintain course. (3 Help: a positive state would have

Satellite communications principles and applications

CERN Document Server

Calcutt, David

1994-01-01

Satellites are increasingly used for global communications, as well as for radio and television transmissions. With the growth of mobile communications, and of digital technology, the use of satellite systems is set to expand substantially and already all students of electronics or communications engineering must study the subject.This book steers a middle path between offering a basic understanding of the process of communication by satellite and the methodology used; and the extensive mathematical analysis normally adopted in similar texts. It presents the basic concepts, using as mu

Influence of satellite alerts on the efficiency of aircraft monitoring of maritime oil pollution in German waters

Science.gov (United States)

Helmke, Peer; Baschek, Björn; Hunsänger, Thomas; Kranz, Susanne

2014-10-01

For detecting accidental and illegal pollution by mineral oil, the German exclusive economic zone and surrounding waters have been monitored by aircraft operationally for more than 25 years. Aircraft surveillance uses predominantly Side-Looking-Airborne-Radar for visualization of the effect of oil to smoothen capillary waves. A set of near range sensors complements the remote sensing data available for the human operator to classify the detected features as "mineral oil", "natural phenomenon", "other substance" or "unknown" pollution. Today, as an add-on to aerial surveillance, the German Central Command of Maritime Emergencies uses the operational satellite service "CleanSeaNet" provided by the European Maritime Safety Agency: Radar satellite data is analyzed in near real time and alerts of potential pollution are sent out. Shortly after receiving the results, aircraft surveillance flights are started by the 3rd Naval Air Wing and the locations of the satellite alerts are checked. Thus, a combined system of satellite and aerial surveillance is in place. The German Federal Institute of Hydrology, BfG, has access to the data of the pollution events detected during these flights and the corresponding meta-data of flights and satellite images. In this work, a period of two years of this data is analyzed. The probability to detect pollutions is evaluated for (A) flight missions associated with satellite scenes, and (B) additional flights performed independently from satellite scenes. Thus, the influence of satellite alerts on the efficiency of aircraft monitoring is investigated. Coverage and coordination of the monitoring by aircraft and satellite are assessed and implications for the operational monitoring are discussed.

Living antennas on communication satellites

DEFF Research Database (Denmark)

Lumholt, Michael

2003-01-01

Crises change the global pattern of communication. The communications problems occur because the satellites are optimized to cover specific geographic areas, and these areas cannot be altered once the satellites are in Earth orbit. An effective solution to the problem is to equip communication sa...... satellites with "living" antennas that can adjust their radiation coverage areas according to the new demands. The development of living antennas is, therefore, among the focus areas identified and supported by the European Space Agency, ESA....

Leveraging the NPS Femto Satellite for Alternative Satellite Communication Networks

Science.gov (United States)

2017-09-01

programmed for eventual integration with the Iridium Network , which is then tested. C. THESIS ORGANIZATION The thesis addresses these questions...NPS FEMTO SATELLITE FOR ALTERNATIVE SATELLITE COMMUNICATION NETWORKS by Faisal S. Alshaya September 2017 Co-Advisors: Steven J. Iatrou...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE LEVERAGING THE NPS FEMTO SATELLITE FOR ALTERNATIVE SATELLITE COMMUNICATION NETWORKS 5

Space industrialization - Education. [via communication satellites

Science.gov (United States)

Joels, K. M.

1978-01-01

The components of an educational system based on, and perhaps enhanced by, space industrialization communications technology are considered. Satellite technology has introduced a synoptic distribution system for various transmittable educational media. The cost of communications satellite distribution for educational programming has been high. It has, therefore, been proposed to utilize Space Shuttle related technology and Large Space Structures (LSS) to construct a system with a quantum advancement in communication capability and a quantum reduction in user cost. LSS for communications purposes have three basic advantages for both developed and emerging nations, including the ability to distribute signals over wide geographic areas, the reduced cost of satellite communications systems versus installation of land based systems, and the ability of a communication satellite system to create instant educational networks.

The Emerging Trends in Satellite and Wireless Communications ...

Indian Academy of Sciences (India)

Table of contents. The Emerging Trends in Satellite and Wireless Communications Technologies · Satellite Communications · Communications Satellites for Global Coverage · Satellite Transponders · The Four Generations Of Commercial Communication Geo-Sat · PowerPoint Presentation · An Indian Scenario INSAT ...

Activities of Canadian Satellite Communications, Inc.

Science.gov (United States)

1992-12-01

Canadian Satellite Communications (Cancom) has as its core business the provision of television and radio signals to cable systems in Canada, with the objective of making affordable broadcast signals available to remote and/or small communities. Cancom also provides direct-to-home services to backyard receiving dishes, as well as satellite digital data business communications services, satellite business television, and satellite network services. Its business communication services range from satellite links for big-city businesses with small branch operations located far from major centers, to a mobile messaging and tracking system for the trucking industry. Revenues in 1992 totalled $48,212,000 and net income was just over $7 million. Cancom bought 10 percent interest in Leosat Corp. of Washington, DC, who are seeking approval to operate a position locator network from low-orbit satellites. Cancom has also become a partner in SovCan Star Satellite Communications Inc., which will build an international satellite system in partnership with Russia. The first satellite in this east-west business network will be placed in a Russian orbital slot over the Atlantic by 1996, and a second satellite will follow for the Pacific region. This annual report of Cancom's activities for 1992 includes financial statements and a six year financial review.

Mobile satellite service communications tests using a NASA satellite

Science.gov (United States)

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

1995-01-01

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.

Soviet satellite communications science and technology

Energy Technology Data Exchange (ETDEWEB)

Birch, J.N.; Campanella, S.J.; Gordon, G.D.; McElroy, D.R.; Pritchard, W.L.; Stamminger, R.

1991-08-01

This is a report by six US scientists and engineers concerning the current state of the art and projections of future Soviet satellite communications technologies. The panel members are experts in satellite stabilization, spacecraft environments, space power generation, launch systems, spacecraft communications sciences and technologies, onboard processing, ground stations, and other technologies that impact communications. The panel assessed the Soviet ability to support high-data-rate space missions at 128 Mbps by evaluating current and projected Soviet satellite communications technologies. A variety of space missions were considered, including Earth-to-Earth communications via satellites in geostationary or highly elliptical orbits, those missions that require space-to-Earth communications via a direct path and those missions that require space-to-Earth communications via a relay satellite. Soviet satellite communications capability, in most cases, is 10 years behind that of the United States and other industrialized nations. However, based upon an analysis of communications links needed to support these missions using current Soviet capabilities, it is well within the current Soviet technology to support certain space missions outlined above at rates of 128 Mbps or higher, although published literature clearly shows that the Soviet Union has not exceeded 60 Mbps in its current space system. These analyses are necessary but not sufficient to determine mission data rates, and other technologies such as onboard processing and storage could limit the mission data rate well below that which could actually be supported via the communications links. Presently, the Soviet Union appears to be content with data rates in the low-Earth-orbit relay via geostationary mode of 12 Mbps. This limit is a direct result of power amplifier limits, spacecraft antenna size, and the utilization of K{sub u}-band frequencies. 91 refs., 16 figs., 15 tabs.

Maritime Aerosol Network optical depth measurements and comparison with satellite retrievals from various different sensors

Science.gov (United States)

Smirnov, Alexander; Petrenko, Maksym; Ichoku, Charles; Holben, Brent N.

2017-10-01

The paper reports on the current status of the Maritime Aerosol Network (MAN) which is a component of the Aerosol Robotic Network (AERONET). A public domain web-based data archive dedicated to MAN activity can be found at https://aeronet.gsfc.nasa.gov/new_web/maritime_aerosol_network.html . Since 2006 over 450 cruises were completed and the data archive consists of more than 6000 measurement days. In this work, we present MAN observations collocated with MODIS Terra, MODIS Aqua, MISR, POLDER, SeaWIFS, OMI, and CALIOP spaceborne aerosol products using a modified version of the Multi-Sensor Aerosol Products Sampling System (MAPSS) framework. Because of different spatio-temporal characteristics of the analyzed products, the number of MAN data points collocated with spaceborne retrievals varied between 1500 matchups for MODIS to 39 for CALIOP (as of August 2016). Despite these unavoidable sampling biases, latitudinal dependencies of AOD differences for all satellite sensors, except for SeaWIFS and POLDER, showed positive biases against ground truth (i.e. MAN) in the southern latitudes (<50° S), and substantial scatter in the Northern Atlantic "dust belt" (5°-15° N). Our analysis did not intend to determine whether satellite retrievals are within claimed uncertainty boundaries, but rather show where bias exists and corrections are needed.

Ground test of satellite constellation based quantum communication

OpenAIRE

Liao, Sheng-Kai; Yong, Hai-Lin; Liu, Chang; Shentu, Guo-Liang; Li, Dong-Dong; Lin, Jin; Dai, Hui; Zhao, Shuang-Qiang; Li, Bo; Guan, Jian-Yu; Chen, Wei; Gong, Yun-Hong; Li, Yang; Lin, Ze-Hong; Pan, Ge-Sheng

2016-01-01

Satellite based quantum communication has been proven as a feasible way to achieve global scale quantum communication network. Very recently, a low-Earth-orbit (LEO) satellite has been launched for this purpose. However, with a single satellite, it takes an inefficient 3-day period to provide the worldwide connectivity. On the other hand, similar to how the Iridium system functions in classic communication, satellite constellation (SC) composed of many quantum satellites, could provide global...

Protected transitional solution to transformational satellite communications

Science.gov (United States)

Brand, Jerry C.

2005-06-01

As the Warfighter progresses into the next generation battlefield, transformational communications become evident as an enabling technology. Satellite communications become even more vital as the battles range over greater non-contiguous spaces. While current satellite communications provide suitable beyond line-of-sight communications and the Transformational Communications Architecture (TCA) sets the stage for sound information exchange, a realizable transition must occur to ensure successful succession to this higher level. This paper addresses the need for a planned escalation to the next generation satellite communications architecture and offers near-term alternatives. Commercial satellite systems continue to enable the Warfighter to reach back to needed information resources, providing a large majority of available bandwidth. Four areas of concentration for transition include encrypted Telemetry, Tracking and Control (or Command) (TT&C), encrypted and covered data, satellite attack detection and protection, and operational mobility. Solution methodologies include directly embedding COMSEC devices in the satellites and terminals, and supplementing existing terminals with suitable equipment and software. Future satellites planned for near-term launches can be adapted to include commercial grade and higher-level secure equipment. Alternately, the expected use of programmable modems (Software Defined Radios (SDR)) enables incorporation of powerful cipher methods approaching military standards as well as waveforms suitable for on-the-move operation. Minimal equipment and software additions on the satellites can provide reasonable attack detection and protection methods in concert with the planned satellite usage. Network management suite modifications enable cohesive incorporation of these protection schemes. Such transitional ideas offer a smooth and planned transition as the TCA takes life.

High power communication satellites power systems study

International Nuclear Information System (INIS)

Josloff, A.T.; Peterson, J.R.

1994-01-01

This paper discusses a DOE-funded study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. This study brings together a preeminent US Industry/Russian team to cooperate on the role of high power communication satellites in the rapidly expanding communications revolution. These high power satellites play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities will be significant

Satellite Communication and Long Distance Education

OpenAIRE

Hafied Cangara

2016-01-01

Since Indonesia introduced communication satellite for telecommunication network, the satellite has brought a number of advantages for national development in various areas, such as telephone network, mass media development, business, education, politics, security and national defence as well as regional and International cooperation. In education, satellite communication could be used for long-distance learning as implemented by 13 state universities in eastern parts of Indonesia. It is also...

ESA's satellite communications programme

Science.gov (United States)

Bartholome, P.

1985-02-01

The developmental history, current status, and future plans of the ESA satellite-communications programs are discussed in a general survey and illustrated with network diagrams and maps. Consideration is given to the parallel development of national and European direct-broadcast systems and telecommunications networks, the position of the European space and electronics industries in the growing world market, the impact of technological improvements (both in satellite systems and in ground-based networks), and the technological and commercial advantages of integrated space-terrestrial networks. The needs for a European definition of the precise national and international roles of satellite communications, for maximum speed in implementing such decisions (before the technology becomes obsolete), and for increased cooperation and standardization to assure European equipment manufacturers a reasonable share of the market are stressed.

Domestic Communication Satellites

Science.gov (United States)

Horowitz, Andrew

1974-01-01

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)

Clock Management Data Analysis for Satellite Communications

National Research Council Canada - National Science Library

Gross, Rachel; Melkers, Raimond

2005-01-01

The U.S. Naval Research Laboratory has installed GPS-based timing systems in several Defense Satellite Communication System "DSCS-III" satellite communication facilities to support the Single Channel Transponder "SCT" program...

Satellite Communications Using Commercial Protocols

Science.gov (United States)

Ivancic, William D.; Griner, James H.; Dimond, Robert; Frantz, Brian D.; Kachmar, Brian; Shell, Dan

2000-01-01

NASA Glenn Research Center has been working with industry, academia, and other government agencies in assessing commercial communications protocols for satellite and space-based applications. In addition, NASA Glenn has been developing and advocating new satellite-friendly modifications to existing communications protocol standards. This paper summarizes recent research into the applicability of various commercial standard protocols for use over satellite and space- based communications networks as well as expectations for future protocol development. It serves as a reference point from which the detailed work can be readily accessed. Areas that will be addressed include asynchronous-transfer-mode quality of service; completed and ongoing work of the Internet Engineering Task Force; data-link-layer protocol development for unidirectional link routing; and protocols for aeronautical applications, including mobile Internet protocol routing for wireless/mobile hosts and the aeronautical telecommunications network protocol.

Advanced mobile satellite communications using COMETS satellite in MM-wave and Ka-band

Science.gov (United States)

Ohmori, Shingo; Isobe, Shunkichi; Takeuchi, Makoto; Naito, Hideyuki

1993-01-01

Early in the 21st century, the demand for personal communications using mobile, hand-held, and VSAT terminals will rapidly increase. In a future system, many different types of services should be provided with one-hop connection. The Communications Research Laboratory (CRL) has studied a future advanced mobile satellite communications system using millimeter wave and Ka band. In 1990, CRL started the Communications and Broadcasting Engineering Test Satellite (COMETS) project. The satellite has been developed in conjunction with NASDA and will be launched in 1997. This paper describes the COMETS payload configuration and the experimental system for the advanced mobile communications mission.

POSSIBILITIES OF UAS FOR MARITIME MONITORING

Directory of Open Access Journals (Sweden)

A. Klimkowska

2016-06-01

Full Text Available In the last few years, Unmanned Aircraft Systems (UAS have become more important and its use for different application is appreciated. At the beginning UAS were used for military purposes. These successful applications initiated interest among researchers to find uses of UAS for civilian purposes, as they are alternative to both manned and satellite systems in acquiring high-resolution remote sensing data at lower cost while long flight duration. As UAS are built from many components such as unmanned aerial vehicle (UAV, sensing payloads, communication systems, ground control stations, recovery and launch equipment, and supporting equipment, knowledge about its functionality and characteristics is crucial for missions. Therefore, finding appropriate configuration of all elements to fulfill requirements of the mission is a very difficult, yet important task. UAS may be used in various maritime applications such as ship detection, red tide detection and monitoring, border patrol, tracking of pollution at sea and hurricane monitoring just to mention few. One of the greatest advantages of UAV is their ability to fly over dangerous and hazardous areas, where sending manned aircraft could be risky for a crew. In this article brief description of aerial unmanned system components is introduced. Firstly characteristics of unmanned aerial vehicles are presented, it continues with introducing inertial navigation system, communication systems, sensing payloads, ground control stations, and ground and recovery equipment. Next part introduces some examples of UAS for maritime applications. This is followed by suggestions of key indicators which should be taken into consideration while choosing UAS. Last part talks about configuration schemes of UAVs and sensor payloads suggested for some maritime applications.

Satellite Communication and Long Distance Education

Directory of Open Access Journals (Sweden)

Hafied Cangara

2016-02-01

Full Text Available Since Indonesia introduced communication satellite for telecommunication network, the satellite has brought a number of advantages for national development in various areas, such as telephone network, mass media development, business, education, politics, security and national defence as well as regional and international cooperation. In education, satellite communication could be used for long-distance learning as implemented by 13 state universities in eastern parts of Indonesia. It is also possible to develop the Open University System in teaching and learning process, particularly since the internet technology has been intensively used

Recent Korean R&D in Satellite Communications

Science.gov (United States)

Lee, Ho-Jin; Kim, Jae Moung; Lee, Byung-Seub; Lee, Han; Ryoo, Jang-Soo

The R&D in satellite communications in Korea has been driven mainly by KCC (Korea Communications Commission) but in a small scale compared to Korea space development program organized by MEST (Ministry of Education, Science and Technology). Public and civilian satcom sector R&D has been led mainly by ETRI with small/medium companies contrary to rare investment in private sector while military sector R&D has been orchestrated by ADD with defense industry. By the COMS (Communication, Ocean and Meteorological Satellite) experimental Ka-band payload, Korea pursues a space qualification of own technology for national infrastructure evolution as well as industrialization of space R&D results. Once COMS launched and space qualified in 2009, subsequent application experiments and new technology R&D like UHDTV will entail service and industry promotion. The payload technology is expected for the next Korean commercial satellites or for new OBP satellites. The COMS ground control system and GNSS ground station technologies are under development for COMS operation and enhanced GNSS services along with advent of Galileo respectively. Satellite broadband mobile VSAT based on DVB-S2/RCS (+M) and low profile tracking antennas have been developed for trains, ships, and planes. While APSI is developing GMR-1 based Thuraya handset functions, ETRI is designing IMT-Advanced satellite radio interface for satellite and terrestrial dual-mode handheld communication system like Japanese STICS, with universities' satellite OFDM researches. A 21GHz Ka-band higher-availability scalable HD broadcasting technology and SkyLife's hybrid satellite IPTV technology are being developed. In near term Korea will extend R&D programs to upgrade the space communication infrastructure for universal access to digital opportunity and safer daily life from disaster, and to promote space green IT industrialization, national security, and space resources sovereign. Japanese stakeholders are invited to establish

Estimating Rain Attenuation In Satellite Communication Links

Science.gov (United States)

Manning, R. M.

1991-01-01

Attenuation computed with help of statistical model and meteorological data. NASA Lewis Research Center Satellite Link Attenuation Model (SLAM) program QuickBASIC computer program evaluating static and dynamic statistical assessment of impact of rain attenuation on communication link established between Earth terminal and geosynchronous satellite. Application in specification, design, and assessment of satellite communication links for any terminal location in continental United States. Written in Microsoft QuickBASIC.

Digital, Satellite-Based Aeronautical Communication

Science.gov (United States)

Davarian, F.

1989-01-01

Satellite system relays communication between aircraft and stations on ground. System offers better coverage with direct communication between air and ground, costs less and makes possible new communication services. Carries both voice and data. Because many data exchanged between aircraft and ground contain safety-related information, probability of bit errors essential.

A New Era Begins: Satellite Communications and Development.

Science.gov (United States)

Pelton, Joseph N.

This overview of changes in the field of telecommunications development produced by satellite communications over the last 15 years focuses on applications of satellite systems for educational and health purposes in developing countries. Satellite communications development from 1974 to 1986 is identified as the first stage of telecommunications…

Satellite communications - Intelsat and global patterns

Science.gov (United States)

Astrain, S.

1983-10-01

The global pattern of mankind's population growth is examined, taking into account the exponential increase in population which began only in the 17th century. As world population has grown, trade has increased, and transportation and communications have become vitally important. A revolution in global communications was initiated when Intelsat launched the first international communications satellite, 'Early Bird', in April 1965. Since April 1965, a tremendous development in global communications by means of satellites has taken place. The Intelsat VI satellite will have a capacity of 36,000 telephone circuits plus 2 TV channels, while the capacity of Early Bird was only 240 telephone circuits. Today, Intelsat is truly an international organization which includes 108 member countries. Attention is given to the particular importance of the Intelsat services to the developing countries, the exploration of new technologies and system concepts, and the extension of services to those portions of the global village which have remained electronically isolated.

Anti-jamming Technology in Small Satellite Communication

Science.gov (United States)

Jia, Zixiang

2018-01-01

Small satellite communication has an increasingly important position among the wireless communications due to the advantages of low cost and high technology. However, in view of the case that its relay station stays outside the earth, its uplink may face interference from malicious signal frequently. Here this paper classified enumerates existing interferences, and proposes channel signals as main interference by comparison. Based on a basic digital communication process, then this paper discusses the possible anti - jamming techniques that commonly be realized at all stages in diverse processes, and comes to the conclusion that regarding the spread spectrum technology and antenna anti-jamming technology as fundamental direction of future development. This work provides possible thought for the design of new small satellite communication system with the coexistence of multi - technologies. This basic popular science can be consulted for people interested in small satellite communication.

Technical comparison of several global mobile satellite communications systems

Science.gov (United States)

Comparetto, Gary M.

The era of satellite-based mobile satellite communications (MSC) systems started with the first MARISAT satellite which was launched into a geostationary orbit over the Pacific Ocean in 1976 to provide communications between ships and shore stations. The combination of high cost and unacceptably large equipment has kept the space-based MSC systems from appealing to the wider market of personal mobile communications. The progress made over the last ten years, however, in digital voice processing, satellite technology, and component miniaturization has resulted in the viability of satellite-based mobile satellite communications systems to meet the growing market in personal mobile communications using handsets similar to those currently in use with land-based cellular systems. Three of the more mature LEO/MEO satellite systems are addressed in this paper including GLOBALSTAR, Iridium, and Odyssey. The system architectures of each system are presented along with a description of the satellite and user handset designs and the multiaccess techniques employed. It will be shown that, although a number of similarities exist among the system addressed, each system is unique in a variety of significant design areas. It is concluded that the technical feasibility of satellite-based mobile satellite communications systems seems to be secure. It will be challenging, however, for the vendors to actually develop and deploy these systems in a cost effective, timely, and reliable way that meets a continually evolving set of requirements based upon a rapidly changing technology base.

High power communication satellites power systems study

Science.gov (United States)

Josloff, Allan T.; Peterson, Jerry R.

1995-01-01

This paper discusses a planned study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. These high power satellites can play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities can be significant.

An access alternative for mobile satellite networks

Science.gov (United States)

Wu, W. W.

1988-01-01

Conceptually, this paper discusses strategies of digital satellite communication networks for a very large number of low density traffic stations. These stations can be either aeronautical, land mobile, or maritime. The techniques can be applied to international, domestic, regional, and special purpose satellite networks. The applications can be commercial, scientific, military, emergency, navigational or educational. The key strategy is the use of a non-orthogonal access method, which tolerates overlapping signals. With n being either time or frequency partitions, and with a single overlapping signal allowed, a low cost mobile satellite system can be designed with n squared (n squared + n + 1) number of terminals.

47 CFR 80.1135 - Transmission of maritime safety information.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transmission of maritime safety information. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating Procedures for Distress and Safety Communications § 80.1135 Transmission of maritime safety...

Odyssey, an optimized personal communications satellite system

Science.gov (United States)

Rusch, Roger J.

Personal communications places severe demands on service providers and transmission facilities. Customers are not satisfied with the current levels of service and want improvements. Among the characteristics that users seek are: lower service rates, hand held convenience, acceptable time delays, ubiquitous service, high availability, reliability, and high quality. The space industry is developing commercial space systems for providing mobile communications to personal telephones. Provision of land mobile satellite service is fundamentally different from the fixed satellite service provided by geostationary satellites. In fixed service, the earth based antennas can depend on a clear path from user to satellite. Mobile users in a terrestrial environment commonly encounter blockage due to vegetation, terrain or buildings. Consequently, high elevation angles are of premium value. TRW studied the issues and concluded that a Medium Earth Orbit constellation is the best solution for Personal Communications Satellite Service. TRW has developed Odyssey, which uses twelve satellites in medium altitude orbit to provide personal communications satellite service. The Odyssey communications system projects a multibeam antenna pattern to the Earth. The attitude control system orients the satellites to ensure constant coverage of land mass and coastal areas. Pointing can be reprogrammed by ground control to ensure optimized coverage of the desired service areas. The payload architecture features non-processing, "bent pipe" transponders and matrix amplifiers to ensure dynamic power delivery to high demand areas. Circuit capacity is 3000 circuits per satellite. Each satellite weighs 1917 kg (4226 pounds) at launch and the solar arrays provide 3126 Watts of power. Satellites are launched in pairs on Ariane, Atlas, or other vehicles. Each satellite is placed in a circular orbit at an altitude of 10,354 km. There are three orbit planes inclined at 55° to the equatorial plane

Overview of the Anik C satellites and services

Science.gov (United States)

Smart, F. H.

An overview of the important technical characteristics of the Anik C series of Canadian communications satellites is presented. The system was launched as part of the Telesat Communications payload of the Space Shuttle in 1982. Among the services the system will in the near future provide are: a 27 MHz channel bandwidth television service for pay-TV distribution in Canada; two TV channels for hockey broadcasts and a transportable TV system; a heavy-voice route telephone service for five major Canadian cities; and a telephone system for business voice and data communications. Services anticipated for Anik-C satellites later in the decade include a Single Channel Per Carrier (SCPC) voice and data communications system for British Columbia and the Maritime Provinces, and a direct-to-home broadcast service to be sold to television markets in the United States.

Research of the key technology in satellite communication networks

Science.gov (United States)

Zeng, Yuan

2018-02-01

According to the prediction, in the next 10 years the wireless data traffic will be increased by 500-1000 times. Not only the wireless data traffic will be increased exponentially, and the demand for diversified traffic will be increased. Higher requirements for future mobile wireless communication system had brought huge market space for satellite communication system. At the same time, the space information networks had been greatly developed with the depth of human exploration of space activities, the development of space application, the expansion of military and civilian application. The core of spatial information networks is the satellite communication. The dissertation presented the communication system architecture, the communication protocol, the routing strategy, switch scheduling algorithm and the handoff strategy based on the satellite communication system. We built the simulation platform of the LEO satellites networks and simulated the key technology using OPNET.

Charting a course to maritime excellence in South Africa

CSIR Research Space (South Africa)

Funke, Nicola S

2017-10-01

Full Text Available maritime culture and recognise and learn from our maritime history 1 Foster national maritime pride 3 Develop and communicate a co-authored discourse on South Africa’s maritime history 2 Support maritime historical and archaeological research, training... world-class education and training facilities 6 Build and retain skills in the maritime sector 2 Support and develop maritime-focused technology and innovation 7 Conduct humanities and social science research on pertinent issues 3 Create knowledge...

Satellite communications network design and analysis

CERN Document Server

Jo, Kenneth Y

2011-01-01

This authoritative book provides a thorough understanding of the fundamental concepts of satellite communications (SATCOM) network design and performance assessments. You find discussions on a wide class of SATCOM networks using satellites as core components, as well as coverage key applications in the field. This in-depth resource presents a broad range of critical topics, from geosynchronous Earth orbiting (GEO) satellites and direct broadcast satellite systems, to low Earth orbiting (LEO) satellites, radio standards and protocols.This invaluable reference explains the many specific uses of

Satellite communication from user to user

Science.gov (United States)

Gern, Manfred

Satellite communication systems which allow a multitude of user-to-user, point-to-point, and multipoint connections, are presented. The bit rates are 64 kbit/sec and multiples, up to 1.92 Mbit/sec. If required, the ground-stations are installed at the customer's site or at suitable locations in order to serve several customers. However, technical requirements for station location have also to be fulfulled, in order to avoid interference with terrestrial radio services. The increasing number of participants to Satellite Multi Service and INTELSAT Business Services imposes the solution of the problem of communication using cheap techniques. The changes of the German Federal Post Office also permit the economic use of satellite radio techniques for short distances.

A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks

Science.gov (United States)

Kerczewski, Robert J.; Chomos, Gerald J.; Griner, James H.; Mainger, Steven W.; Martzaklis, Konstantinos S.; Kachmar, Brian A.

2000-01-01

Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will increasingly play a critical role in the aeronautical communications network. At the same time, current ground-based communications links, primarily very high frequency (VHF), will continue to be employed due to cost advantages and legacy issues. Hence a hybrid satellite-terrestrial network, or group of networks, will emerge. The increased complexity of future aeronautical communications networks dictates that system-level modeling be employed to obtain an optimal system fulfilling a majority of user needs. The NASA Glenn Research Center is investigating the current and potential future state of aeronautical communications, and is developing a simulation and modeling program to research future communications architectures for national and global aeronautical needs. This paper describes the primary requirements, the current infrastructure, and emerging trends of aeronautical communications, including a growing role for satellite communications. The need for a hybrid communications system architecture approach including both satellite and ground-based communications links is explained. Future aeronautical communication network topologies and key issues in simulation and modeling of future aeronautical communications systems are described.

Communication Satellite: Nigeria's Efforts at Bridging Digital Divide ...

African Journals Online (AJOL)

Communication Satellite in the wireless age has the potentials of bridging the digital gulf that exists between civilized and developing nation. If well used, communication Satellite is a potent infrastructure of addressing technology convergence for holistic national development. This paper examines Nigeria's technological ...

Potential markets for advanced satellite communications

Science.gov (United States)

Adamson, Steven; Roberts, David; Schubert, Leroy; Smith, Brian; Sogegian, Robert; Walters, Daniel

1993-09-01

This report identifies trends in the volume and type of traffic offered to the U.S. domestic communications infrastructure and extrapolates these trends through the year 2011. To describe how telecommunications service providers are adapting to the identified trends, this report assesses the status, plans, and capacity of the domestic communications infrastructure. Cable, satellite, and radio components of the infrastructure are examined separately. The report also assesses the following major applications making use of the infrastructure: (1) Broadband services, including Broadband Integrated Services Digital Network (BISDN), Switched Multimegabit Data Service (SMDS), and frame relay; (2) mobile services, including voice, location, and paging; (3) Very Small Aperture Terminals (VSAT), including mesh VSAT; and (4) Direct Broadcast Satellite (DBS) for audio and video. The report associates satellite implementation of specific applications with market segments appropriate to their features and capabilities. The volume and dollar value of these market segments are estimated. For the satellite applications able to address the needs of significant market segments, the report also examines the potential of each satellite-based application to capture business from alternative technologies.

Potential markets for advanced satellite communications

Science.gov (United States)

Adamson, Steven; Roberts, David; Schubert, Leroy; Smith, Brian; Sogegian, Robert; Walters, Daniel

1993-01-01

This report identifies trends in the volume and type of traffic offered to the U.S. domestic communications infrastructure and extrapolates these trends through the year 2011. To describe how telecommunications service providers are adapting to the identified trends, this report assesses the status, plans, and capacity of the domestic communications infrastructure. Cable, satellite, and radio components of the infrastructure are examined separately. The report also assesses the following major applications making use of the infrastructure: (1) Broadband services, including Broadband Integrated Services Digital Network (BISDN), Switched Multimegabit Data Service (SMDS), and frame relay; (2) mobile services, including voice, location, and paging; (3) Very Small Aperture Terminals (VSAT), including mesh VSAT; and (4) Direct Broadcast Satellite (DBS) for audio and video. The report associates satellite implementation of specific applications with market segments appropriate to their features and capabilities. The volume and dollar value of these market segments are estimated. For the satellite applications able to address the needs of significant market segments, the report also examines the potential of each satellite-based application to capture business from alternative technologies.

Maritime Aerosol Network as a Component of AERONET - First Results and Comparison with Global Aerosol Models and Satellite Retrievals

Science.gov (United States)

Smirnov, A.; Holben, B. N.; Giles, D. M.; Slutsker, I.; O'Neill, N. T.; Eck, T. F.; Macke, A.; Croot, P.; Courcoux, Y.; Sakerin, S. M.;

Use of Advanced Solar Cells for Commercial Communication Satellites

Science.gov (United States)

Bailey, Sheila G.; Landis, Geoffrey A.

1995-01-01

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Maritime Activities: Requirements for Improving Space Based Solutions

Science.gov (United States)

Cragnolini, A.; Miguel-Lago, M.

2005-03-01

Maritime initiatives cannot be pursued only within their own perimeter. Sector endeavours and the policies which rule over them have wide range implications and several links with other sectors of activity. A well- balanced relationship of sea exploitation, maritime transportation, environmental protection and security ruled by national or international laws, will be a main issue for the future of all kind of maritime activities. Scientific research and technology development, along with enlightened and appropriate institutional regulations are relevant to ensure maritime sustainability.The use of satellite technology for monitoring international agreements should have a close co- ordination and be based on institutional consensus. Frequently, rules and new regulations set by policy makers are not demanding enough due to lack of knowledge about the possibilities offered by available technologies.Law enforcement actions could bring space technology new opportunities to offer solutions for monitoring and verification. Operators should aim at offering space data in a more operational and user-friendly way, providing them with useful and timely information.This paper will analyse the contribution of satellite technology to deal with the specificity of maritime sector, stressing the conditions for both an adequate technology improvement and an effective policy implementation.After analysing the links between maritime activities, space technologies and the institutional environment, the paper identifies some boundary conditions of the future developments. Conclusions are basically a check list for improving the present situation, while a road map is suggested as a matter of a way to proceed.

47 CFR 80.389 - Frequencies for maritime support stations.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequencies for maritime support stations. 80.389 Section 80.389 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Frequencies Maritime Support Stations § 80.389...

Satellite Communication and Development: A Reassessment.

Science.gov (United States)

Hudson, Heather E.

The potential benefits of satellite communications development have been recognized since the notion of a geostationary "space platform" was proposed by Arthur C. Clarke in 1945. Although there have been examples of developmental applications of satellite technology, the promise has been slow in being fulfilled. The history of the…

Network design consideration of a satellite-based mobile communications system

Science.gov (United States)

Yan, T.-Y.

1986-01-01

Technical considerations for the Mobile Satellite Experiment (MSAT-X), the ground segment testbed for the low-cost spectral efficient satellite-based mobile communications technologies being developed for the 1990's, are discussed. The Network Management Center contains a flexible resource sharing algorithm, the Demand Assigned Multiple Access scheme, which partitions the satellite transponder bandwidth among voice, data, and request channels. Satellite use of multiple UHF beams permits frequency reuse. The backhaul communications and the Telemetry, Tracking and Control traffic are provided through a single full-coverage SHF beam. Mobile Terminals communicate with the satellite using UHF. All communications including SHF-SHF between Base Stations and/or Gateways, are routed through the satellite. Because MSAT-X is an experimental network, higher level network protocols (which are service-specific) will be developed only to test the operation of the lowest three levels, the physical, data link, and network layers.

DS-CDMA satellite diversity reception for personal satellite communication: Downlink performance analysis

Science.gov (United States)

DeGaudenzi, Riccardo; Giannetti, Filippo

1995-01-01

The downlink of a satellite-mobile personal communication system employing power-controlled Direct Sequence Code Division Multiple Access (DS-CDMA) and exploiting satellite-diversity is analyzed and its performance compared with a more traditional communication system utilizing single satellite reception. The analytical model developed has been thoroughly validated by means of extensive Monte Carlo computer simulations. It is shown how the capacity gain provided by diversity reception shrinks considerably in the presence of increasing traffic or in the case of light shadowing conditions. Moreover, the quantitative results tend to indicate that to combat system capacity reduction due to intra-system interference, no more than two satellites shall be active over the same region. To achieve higher system capacity, differently from terrestrial cellular systems, Multi-User Detection (MUD) techniques are likely to be required in the mobile user terminal, thus considerably increasing its complexity.

Maritime aerosol network as a component of AERONET – first results and comparison with global aerosol models and satellite retrievals

Directory of Open Access Journals (Sweden)

A. Smirnov

2011-03-01

Full Text Available The Maritime Aerosol Network (MAN has been collecting data over the oceans since November 2006. Over 80 cruises were completed through early 2010 with deployments continuing. Measurement areas included various parts of the Atlantic Ocean, the Northern and Southern Pacific Ocean, the South Indian Ocean, the Southern Ocean, the Arctic Ocean and inland seas. MAN deploys Microtops hand-held sunphotometers and utilizes a calibration procedure and data processing traceable to AERONET. Data collection included areas that previously had no aerosol optical depth (AOD coverage at all, particularly vast areas of the Southern Ocean. The MAN data archive provides a valuable resource for aerosol studies in maritime environments. In the current paper we present results of AOD measurements over the oceans, and make a comparison with satellite AOD retrievals and model simulations.

A Survey of Satellite Communications System Vulnerabilities

National Research Council Canada - National Science Library

Steinberger, Jessica A

2008-01-01

The U.S. military's increasing reliance on commercial and military communications satellites to enable widely-dispersed, mobile forces to communicate makes these space assets increasingly vulnerable to attack by adversaries...

Application of Vision Metrology to In-Orbit Measurement of Large Reflector Onboard Communication Satellite for Next Generation Mobile Satellite Communication

Science.gov (United States)

Akioka, M.; Orikasa, T.; Satoh, M.; Miura, A.; Tsuji, H.; Toyoshima, M.; Fujino, Y.

2016-06-01

Satellite for next generation mobile satellite communication service with small personal terminal requires onboard antenna with very large aperture reflector larger than twenty meters diameter because small personal terminal with lower power consumption in ground base requires the large onboard reflector with high antenna gain. But, large deployable antenna will deform in orbit because the antenna is not a solid dish but the flexible structure with fine cable and mesh supported by truss. Deformation of reflector shape deteriorate the antenna performance and quality and stability of communication service. However, in case of digital beam forming antenna with phased array can modify the antenna beam performance due to adjustment of excitation amplitude and excitation phase. If we can measure the reflector shape precisely in orbit, beam pattern and antenna performance can be compensated with the updated excitation amplitude and excitation phase parameters optimized for the reflector shape measured every moment. Softbank Corporation and National Institute of Information and Communications Technology has started the project "R&D on dynamic beam control technique for next generation mobile communication satellite" as a contracted research project sponsored by Ministry of Internal Affairs and Communication of Japan. In this topic, one of the problem in vision metrology application is a strong constraints on geometry for camera arrangement on satellite bus with very limited space. On satellite in orbit, we cannot take many images from many different directions as ordinary vision metrology measurement and the available area for camera positioning is quite limited. Feasibility of vision metrology application and general methodology to apply to future mobile satellite communication satellite is to be found. Our approach is as follows: 1) Development of prototyping simulator to evaluate the expected precision for network design in zero order and first order 2) Trial

Advanced mobile satellite communications system using Ka and MM-wave bands in Japan's R and D satellite project

Science.gov (United States)

Isobe, Shunkichi; Ohmori, Shingo; Hamamoto, Naokazu; Yamamoto, Minoru

1991-01-01

Communications Research Laboratory (CRL) studied an advanced mobile satellite communications system using Ka and millimeter-wave bands in the R&D Satellite project. The project started in 1990 and the satellite will be launched in 1997. On-board multi-beam interconnecting is one of basic functions to realize one-hop connection among Very Small Aperture Terminals (VSATs), mobile, and hand-held terminals in future mobile satellite communications system. An Intermediate Frequency (IF) filter bank and regenerative transponder are suitable for this function. The transponder configuration of an advanced mobile communications mission of the R&D Satellite for experiment is shown. High power transmitters of Ka and millimeter-wave bands, a 3x3 IF filter band and Single Channel Per Carrier/Time Division Multiplexing (SCPC/TDM) regenerative MODEMS, which will be boarded on the R&D Satellite, are being developed for the purpose of studying the feasibility of advanced mobile communications system.

US development and commercialization of a North American mobile satellite service

Science.gov (United States)

Arnold, Ray J.; Gray, Valerie; Freibaum, Jerry

1990-01-01

U.S. policies promoting applications and commercialization of space technology for the 'benefit of mankind,' and emphasis on international competitiveness, formed the basis of NASA's Mobile Satellite (MSAT) R&D and user experiments program to develop a commercial U.S. Mobile Satellite Service. Exemplifying this philosophy, the MSAT program targets the reduction of technical, regulatory, market, and financial risks that inhibit commercialization. The program strategy includes industry and user involvement in developing and demonstrating advanced technologies, regulatory advocacy, and financial incentives to industry. Approximately two decades of NASA's satellite communications development and demonstrations have contributed to the emergence of a new multi-billion dollar industry for land, aeronautical, and maritime mobile communications via satellite. NASA's R&D efforts are now evolving from the development of 'enabling' ground technologies for VHF, UHF, and L-Band mobile terminals, to Ka-Band terminals offering additional mobility and user convenience.

US development and commercialization of a North American mobile satellite service

Science.gov (United States)

Arnold, Ray J.; Gray, Valerie; Freibaum, Jerry

U.S. policies promoting applications and commercialization of space technology for the 'benefit of mankind,' and emphasis on international competitiveness, formed the basis of NASA's Mobile Satellite (MSAT) R&D and user experiments program to develop a commercial U.S. Mobile Satellite Service. Exemplifying this philosophy, the MSAT program targets the reduction of technical, regulatory, market, and financial risks that inhibit commercialization. The program strategy includes industry and user involvement in developing and demonstrating advanced technologies, regulatory advocacy, and financial incentives to industry. Approximately two decades of NASA's satellite communications development and demonstrations have contributed to the emergence of a new multi-billion dollar industry for land, aeronautical, and maritime mobile communications via satellite. NASA's R&D efforts are now evolving from the development of 'enabling' ground technologies for VHF, UHF, and L-Band mobile terminals, to Ka-Band terminals offering additional mobility and user convenience.

SDR Implementation for Satellite Communication

OpenAIRE

Jakobsson, Carin; Sjödin, Olof

2017-01-01

SDR (Software Defined Radio) is a radio communicationsystem that has been of great interest and developmentover the last 20 years. It decreases communication costs significantlyas it replaces expensive analogue system components withcheap and flexible digital ones. In this article we describe anSDR implementation for communication with the SEAM (SmallExplorer for Advances Missions) satellite, a CubeSat satellitethat will perform high quality magnetic measurements in theEarth orbit. The projec...

Communication satellites to enter a new age of flexibility

Science.gov (United States)

Balty, Cédric; Gayrard, Jean-Didier; Agnieray, Patrick

2009-07-01

To cope with the economical and technical evolutions of the communication market and to better compete with or complement terrestrial networks, satellite operators are requiring more flexible satellites. It allows a better fleet planning potential and back-up policy, a more standardized and efficient procurement process, mission adaptation to market evolution and the possibility of early entry in new markets. New technologies that are developed either for terrestrial networks or for space defense applications would become soon available to satellite and equipment manufacturers. A skilful mix of these new technologies with the older and more mature ones should boost satellite performances and bring flexibility to the new generation of communication satellites. This paper reviews the economical and technical environment of the space communication business for the next decade. It identifies the needs and levels of flexibility that are required by the market but also allowed by technologies, in both a top-down and bottom-up approach.

Uses of communication satellites in water utility operations

Science.gov (United States)

Tighe, W. S.

This paper proposes a system to serve the communications needs of the operating side of a water utility and estimates the requirements and capabilities of the equipment needed. The system requires the shared use of a satellite transponder with 100% backup. Messages consist of data packets containing data and control information, plus voice transmission. Satellite communication may have a price advantage in some instances over wire line or VHF radio and have greater survivability in case of a natural disaster. Water and other utilities represent a significant market for low cost mass produced satellite earth terminals.

Maritime health: a review with suggestions for research.

Science.gov (United States)

MacLachlan, Malcolm; Kavanagh, Bill; Kay, Alison

2012-01-01

International maritime health has largely developed within the sphere of occupational health services and international health problems. We reviewed publications in the journal International Maritime Health from 2000 to 2010 to establish the coverage of the journal and the scope of research in maritime health. We identified six thematic categories: healthcare access, delivery and integration; telehealth; non-communicable diseases and physical health problems; communicable diseases; psychological functioning and health; and safety-related issues. We describe the research within these themes and report on their publication prominence. We also analyse the research in terms of its geographical focus, the population groups addressed and the research methodologies used. We suggest a broadening of maritime research to include randomised controlled trials, longitudinal studies and more qualitative research; more research addressing the context for non-European seafarers; and research on seafarers spouses and family supports and obligations. We also recommend more research on psychosocial and cultural issues and on telehealth, as well as the development of a stronger systems perspective for promoting maritime health.

Accurate beacon positioning method for satellite-to-ground optical communication.

Science.gov (United States)

Wang, Qiang; Tong, Ling; Yu, Siyuan; Tan, Liying; Ma, Jing

2017-12-11

In satellite laser communication systems, accurate positioning of the beacon is essential for establishing a steady laser communication link. For satellite-to-ground optical communication, the main influencing factors on the acquisition of the beacon are background noise and atmospheric turbulence. In this paper, we consider the influence of background noise and atmospheric turbulence on the beacon in satellite-to-ground optical communication, and propose a new locating algorithm for the beacon, which takes the correlation coefficient obtained by curve fitting for image data as weights. By performing a long distance laser communication experiment (11.16 km), we verified the feasibility of this method. Both simulation and experiment showed that the new algorithm can accurately obtain the position of the centroid of beacon. Furthermore, for the distortion of the light spot through atmospheric turbulence, the locating accuracy of the new algorithm was 50% higher than that of the conventional gray centroid algorithm. This new approach will be beneficial for the design of satellite-to ground optical communication systems.

Development of Mission and Spacecraft Dynamics Analysis System for Geostationary Communication Satellite

Directory of Open Access Journals (Sweden)

Hyeon Cheol Gong

1998-06-01

Full Text Available We consider the motion of the subsystems as separate bodies as well as the entire satellite for the attitude and orbit control of a communication satellite by multi-body modeling technique. Thus, the system can be applied to a general communication satellite as well as a specific communication satellite, i.e. Koreasat I, II. The simulation results can be viewed by two-dimensional graphics and three-dimensional animation. The graphical user interface (GUI makes its usage much simpler. We have simulated a couple of scenarios for Koreasat I, II which are being operated as geostationary communication satellites to verify the system performance.

Some design considerations for planetary relay communications satellites.

Science.gov (United States)

Barber, T. A.; Bourke, R. D.

1966-01-01

Items affecting information transmitted from payload landed on remote planet to Earth via communications satellite including orbit, transmission policy and orbit injection error effect on communication capability

Advanced Communications Technology Satellite (ACTS) and potential system applications

Science.gov (United States)

Wright, David L.; Balombin, Joseph R.; Sohn, Philip Y.

1990-01-01

A description of the advanced communications technology satellite (ACTS) system is given with special emphasis on the communication characteristics. Potential satellite communications scenarios, including future operational ACTS-like satellite systems, are discussed. The description of the ACTS system updates previously published ACTS system references. Detailed information on items such as experimental ground stations is presented. The potential services can be generically described as voice, video, and data services. The implementation of these services on future operational ACTS-like systems can lead to unique quality, flexibility, and capacity characteristics at lower service costs. The specific service applications that could be supported range from low to high data rates and include both domestic and international applications.

Next generation satellite communications networks

Science.gov (United States)

Garland, P. J.; Osborne, F. J.; Streibl, I.

The paper introduces two potential uses for new space hardware to permit enhanced levels of signal handling and switching in satellite communication service for Canada. One application involves increased private-sector services in the Ku band; the second supports new personal/mobile services by employing higher levels of handling and switching in the Ka band. First-generation satellite regeneration and switching experiments involving the NASA/ACTS spacecraft are described, where the Ka band and switching satellite network problems are emphasized. Second-generation satellite development is outlined based on demand trends for more packet-based switching, low-cost earth stations, and closed user groups. A demonstration mission for new Ka- and Ku-band technologies is proposed, including the payload configuration. The half ANIK E payload is shown to meet the demonstration objectives, and projected to maintain a fully operational payload for at least 10 years.

Scheduling algorithm for data relay satellite optical communication based on artificial intelligent optimization

Science.gov (United States)

Zhao, Wei-hu; Zhao, Jing; Zhao, Shang-hong; Li, Yong-jun; Wang, Xiang; Dong, Yi; Dong, Chen

2013-08-01

Optical satellite communication with the advantages of broadband, large capacity and low power consuming broke the bottleneck of the traditional microwave satellite communication. The formation of the Space-based Information System with the technology of high performance optical inter-satellite communication and the realization of global seamless coverage and mobile terminal accessing are the necessary trend of the development of optical satellite communication. Considering the resources, missions and restraints of Data Relay Satellite Optical Communication System, a model of optical communication resources scheduling is established and a scheduling algorithm based on artificial intelligent optimization is put forwarded. According to the multi-relay-satellite, multi-user-satellite, multi-optical-antenna and multi-mission with several priority weights, the resources are scheduled reasonable by the operation: "Ascertain Current Mission Scheduling Time" and "Refresh Latter Mission Time-Window". The priority weight is considered as the parameter of the fitness function and the scheduling project is optimized by the Genetic Algorithm. The simulation scenarios including 3 relay satellites with 6 optical antennas, 12 user satellites and 30 missions, the simulation result reveals that the algorithm obtain satisfactory results in both efficiency and performance and resources scheduling model and the optimization algorithm are suitable in multi-relay-satellite, multi-user-satellite, and multi-optical-antenna recourses scheduling problem.

Reusable Communication Infrastructure for Small Satellites

Data.gov (United States)

National Aeronautics and Space Administration — The research goal of this project is to develop a comprehensive communications reference architecture that is applicable to a wide variety of small satellite...

Effect of Ionosphere on Geostationary Communication Satellite Signals

Science.gov (United States)

Erdem, Esra; Arikan, Feza; Gulgonul, Senol

2016-07-01

Geostationary orbit (GEO) communications satellites allow radio, television, and telephone transmissions to be sent live anywhere in the world. They are extremely important in daily life and also for military applications. Since, satellite communication is an expensive technology addressing crowd of people, it is critical to improve the performance of this technology. GEO satellites are at 35,786 kilometres from Earth's surface situated directly over the equator. A satellite in a geostationary orbit (GEO) appears to stand still in the sky, in a fixed position with respect to an observer on the earth, because the satellite's orbital period is the same as the rotation rate of the Earth. The advantage of this orbit is that ground antennas can be fixed to point towards to satellite without their having to track the satellite's motion. Radio frequency ranges used in satellite communications are C, X, Ku, Ka and even EHG and V-band. Satellite signals are disturbed by atmospheric effects on the path between the satellite and the receiver antenna. These effects are mostly rain, cloud and gaseous attenuation. It is expected that ionosphere has a minor effect on the satellite signals when the ionosphere is quiet. But there are anomalies and perturbations on the structure of ionosphere with respect to geomagnetic field and solar activity and these conditions may cause further affects on the satellite signals. In this study IONOLAB-RAY algorithm is adopted to examine the effect of ionosphere on satellite signals. IONOLAB-RAY is developed to calculate propagation path and characteristics of high frequency signals. The algorithm does not have any frequency limitation and models the plasmasphere up to 20,200 km altitude, so that propagation between a GEO satellite and antenna on Earth can be simulated. The algorithm models inhomogeneous, anisotropic and time dependent structure of the ionosphere with a 3-D spherical grid geometry and calculates physical parameters of the

New Channel Coding Methods for Satellite Communication

Directory of Open Access Journals (Sweden)

J. Sebesta

2010-04-01

Full Text Available This paper deals with the new progressive channel coding methods for short message transmission via satellite transponder using predetermined length of frame. The key benefits of this contribution are modification and implementation of a new turbo code and utilization of unique features with applications of methods for bit error rate estimation and algorithm for output message reconstruction. The mentioned methods allow an error free communication with very low Eb/N0 ratio and they have been adopted for satellite communication, however they can be applied for other systems working with very low Eb/N0 ratio.

Basin-Wide Maritime Awareness From Multi-Source Ship Reporting Data

Directory of Open Access Journals (Sweden)

Harm Greidanus

2013-06-01

Full Text Available A system was set up to ingest automatic ship position reports (terrestrial and satellite AIS, LRIT and fuse these into a Maritime Situational Picture, tracking the ships within an ocean basin-wide area of interest in real time. Trial runs were made over several months, collecting reporting data from a number of different sources, over the Gulf of Aden and the Western Indian Ocean. Also satellite radar surveillance was carried out in order to sample the presence of non-reporting ships. The trial showed that satellite AIS is a powerful tool for basin-wide ship traffic monitoring; that multiple AIS satellites are needed for sufficient completeness and update rate; and that coastal AIS and LRIT still provide essential complements to the satellite AIS data. The radar survey showed that about half of the radar-detected ships are not seen in the reporting data. The ultimate purpose of this work is to support the countries around the Horn of Africa in the fight against piracy and to help build their capacity to deliver maritime security and safety.

Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)

Science.gov (United States)

Hoder, Douglas; Bergamo, Marcos

1996-01-01

The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

COMMUNICATION SATELLITES FOR EDUCATION, SCIENCE AND CULTURE. REPORTS AND PAPERS ON MASS COMMUNICATION, NO. 53.

Science.gov (United States)

SCHRAMM, WILBUR

THE TECHNOLOGY OF COMMUNICATION SATELLITES IS SUFFICIENTLY ADVANCED THAT CONCERNED AGENCIES, SUCH AS UNESCO, SHOULD BEGIN TO PLAN FOR THEIR USE IN EXCHANGE OF DATA, NEWS TRANSMISSION, CULTURAL EXCHANGE, AND EDUCATION. GROUNDWORK IN TECHNOLOGY, IN THE DESIGN OF A SATELLITE COMMUNICATION SYSTEM, IN VALUE JUDGMENTS, IN AGREEMENTS OF COOPERATION AND…

Advanced Communications Technology Satellite (ACTS): Four-Year System Performance

Science.gov (United States)

Acosta, Roberto J.; Bauer, Robert; Krawczyk, Richard J.; Reinhart, Richard C.; Zernic, Michael J.; Gargione, Frank

1999-01-01

The Advanced Communications Technology Satellite (ACTS) was conceived at the National Aeronautics and Space Administration (NASA) in the late 1970's as a follow-on program to ATS and CTS to continue NASA's long history of satellite communications projects. The ACTS project set the stage for the C-band satellites that started the industry, and later the ACTS project established the use of Ku-band for video distribution and direct-to-home broadcasting. ACTS, launched in September 1993 from the space shuttle, created a revolution in satellite system architecture by using digital communications techniques employing key technologies such as a fast hopping multibeam antenna, an on-board baseband processor, a wide-band microwave switch matrix, adaptive rain fade compensation, and the use of 900 MHz transponders operating at Ka-band frequencies. This paper describes the lessons learned in each of the key ACTS technology areas, as well as in the propagation investigations.

DOA estimation for attitude determination on communication satellites

Directory of Open Access Journals (Sweden)

Yang Bin

2014-06-01

Full Text Available In order to determine an appropriate attitude of three-axis stabilized communication satellites, this paper describes a novel attitude determination method using direction of arrival (DOA estimation of a ground signal source. It differs from optical measurement, magnetic field measurement, inertial measurement, and global positioning system (GPS attitude determination. The proposed method is characterized by taking the ground signal source as the attitude reference and acquiring attitude information from DOA estimation. Firstly, an attitude measurement equation with DOA estimation is derived in detail. Then, the error of the measurement equation is analyzed. Finally, an attitude determination algorithm is presented using a dynamic model, the attitude measurement equation, and measurement errors. A developing low Earth orbit (LEO satellite which tests mobile communication technology with smart antennas can be stabilized in three axes by corporately using a magnetometer, reaction wheels, and three-axis magnetorquer rods. Based on the communication satellite, simulation results demonstrate the effectiveness of the method. The method could be a backup of attitude determination to prevent a system failure on the satellite. Its precision depends on the number of snapshots and the input signal-to-noise ratio (SNR with DOA estimation.

Satellite-enabled educational services specification and requirements analysis based on user feedback

OpenAIRE

Tsekeridou, Sofia; Tiropanis, Thanassis; Rorris, Dimitris; Constantinos, Makropoulos; Serif, Tacha; Stergioulas, Lampros

2008-01-01

Advanced tele-education services provision in remote geographically dispersed user communities (such as agriculture and maritime), based on the specific needs and requirements of such communities, implies significant infrastructural and broadband connectivity requirements for rich media, timely and quality-assured content delivery and interactivity. The solution to broadband access anywhere is provided by satellite-enabled communication infrastructures. This paper aims to present such satelli...

Spread spectrum mobile communication experiment using ETS-V satellite

Science.gov (United States)

Ikegami, Tetsushi; Suzuki, Ryutaro; Kadowaki, Naoto; Taira, Shinichi; Sato, Nobuyasu

1990-01-01

The spread spectrum technique is attractive for application to mobile satellite communications, because of its random access capability, immunity to inter-system interference, and robustness to overloading. A novel direct sequence spread spectrum communication equipment is developed for land mobile satellite applications. The equipment is developed based on a matched filter technique to improve the initial acquisition performance. The data rate is 2.4 kilobits per sec. and the PN clock rate is 2.4552 mega-Hz. This equipment also has a function of measuring the multipath delay profile of land mobile satellite channel, making use of a correlation property of a PN code. This paper gives an outline of the equipment and the field test results with ETS-V satellite.

Next-Generation NASA Earth-Orbiting Relay Satellites: Fusing Optical and Microwave Communications

Science.gov (United States)

Israel, David J.; Shaw, Harry

2018-01-01

NASA is currently considering architectures and concepts for the generation of relay satellites that will replace the Tracking and Data Relay Satellite (TDRS) constellation, which has been flying since 1983. TDRS-M, the last of the second TDRS generation, launched in August 2017, extending the life of the TDRS constellation beyond 2030. However, opportunities exist to re-engineer the concepts of geosynchronous Earth relay satellites. The needs of the relay satellite customers have changed dramatically over the last 34 years since the first TDRS launch. There is a demand for greater bandwidth as the availability of the traditional RF spectrum for space communications diminishes and the demand for ground station access grows. The next generation of NASA relay satellites will provide for operations that have factored in these new constraints. In this paper, we describe a heterogeneous constellation of geosynchronous relay satellites employing optical and RF communications. The new constellation will enable new optical communications services formed by user-to-space relay, space relay-to-space relay and space relay-to-ground links. It will build upon the experience from the Lunar Laser Communications Demonstration from 2013 and the Laser Communications Relay Demonstration to be launched in 2019.Simultaneous to establishment of the optical communications space segment, spacecraft in the TDRS constellation will be replaced with RF relay satellites with targeted subsets of the TDRS capabilities. This disaggregation of the TDRS service model will allow for flexibility in replenishing the needs of legacy users as well as addition of new capabilities for future users. It will also permit the U.S. government access to launch capabilities such as rideshare and to hosted payloads that were not previously available.In this paper, we also explore how the next generation of Earth relay satellites provides a significant boost in the opportunities for commercial providers to the

Next-Generation NASA Earth-Orbiting Relay Satellites: Fusing Microwave and Optical Communications

Science.gov (United States)

Israel, David J.

2018-01-01

NASA is currently considering architectures and concepts for the generation of relay satellites that will replace the Tracking and Data Relay Satellite (TDRS) constellation, which has been flying since 1983. TDRS-M, the last of the second TDRS generation, launched in August 2017, extending the life of the TDRS constellation beyond 2030. However, opportunities exist to re-engineer the concepts of geosynchronous Earth relay satellites. The needs of the relay satellite customers have changed dramatically over the last 34 years since the first TDRS launch. There is a demand for greater bandwidth as the availability of the traditional RF spectrum for space communications diminishes and the demand for ground station access grows. The next generation of NASA relay satellites will provide for operations that have factored in these new constraints. In this paper, we describe a heterogeneous constellation of geosynchronous relay satellites employing optical and RF communications. The new constellation will enable new optical communications services formed by user-to-space relay, space relay-to-space relay and space relay-to-ground links. It will build upon the experience from the Lunar Laser Communications Demonstration from 2013 and the Laser Communications Relay Demonstration to be launched in 2019.Simultaneous to establishment of the optical communications space segment, spacecraft in the TDRS constellation will be replaced with RF relay satellites with targeted subsets of the TDRS capabilities. This disaggregation of the TDRS service model will allow for flexibility in replenishing the needs of legacy users as well as addition of new capabilities for future users. It will also permit the U.S. government access to launch capabilities such as rideshare and to hosted payloads that were not previously available. In this paper, we also explore how the next generation of Earth relay satellites provides a significant boost in the opportunities for commercial providers to the

Maritime English as a code-tailored ESP: Genre-based curriculum development as a way out

Directory of Open Access Journals (Sweden)

Yan Zhang

2018-04-01

Full Text Available Maritime English (ME, as a type of English for Specific Purposes (ESP, is somewhat different in that its instruction and research are founded on specific international legal procedures. Thus, it is vital to determine an ESP framework that bridges the code-tailored ME curriculum development with the communicative language teaching approach. This paper reports on the revision of the International Maritime Organization (IMO’s Model Course 3.17, Maritime English, where an integrated genre-based ESP framework helps to achieve the balance between language learning’s “wide-angled” quality and ME’s legal consistency. It is argued that code-tailored ME competences find expressions in maritime domain-specific genres; those are the typical sets of English communicative events that seafarers are involved in while achieving their maritime professional objectives. The curriculum can be designed as to integrate linguistic systems, professional motivation and behaviors, communicative skills and cultural awareness into the teaching process, which entails a process of learning Maritime English while taking maritime domain-specific action. Specifically, the principle of genre as social action apprises the two-stage syllabus mapping, that is, General Maritime English (GME and Specialized Maritime English (SME. In GME, the focus is placed on the linguistic content and how language tasks embedded in the maritime contexts are fulfilled; in SME, the focus is placed on the professional content and how the maritime workplace duties and identities are fulfilled through the English language. As such, syllabus mapping calculates the discursion-profession correlation and helps to ensure that code-tailored ME teaching is communicative performance-oriented. Thus, the multi-syllabus task design and content selection must consistently maintain the genre-based balance on the linguistic-communicative continuum. As a result, the English linguistic systems underlying the

Computer-Aided Communication Satellite System Analysis and Optimization.

Science.gov (United States)

Stagl, Thomas W.; And Others

Various published computer programs for fixed/broadcast communication satellite system synthesis and optimization are discussed. The rationale for selecting General Dynamics/Convair's Satellite Telecommunication Analysis and Modeling Program (STAMP) in modified form to aid in the system costing and sensitivity analysis work in the Program on…

Relief for maritime medical emergencies through telematics.

Science.gov (United States)

Anogianakis, G; Maglavera, S; Pomportsis, A

1998-12-01

MERMAID is a European Union (EU)-financed maritime telemedicine project with global reach and 24-h multilingual capability, so as to serve multinational crews working in the isolation of the world's oceans. It provides a model for the provision of healthcare services based on the electronic transmission of medical information via ISDN-based video conferencing. This model is not limited to medical diagnostics, but it encompasses all cases in which the actual delivery of healthcare services involves a patient who is not located where the provider is. Its implementation requires the commissioning of an extensive telecommunications infrastructure that includes both satellite transmission for ship to shore communication and an extensive ground-based network for summoning expert medical help from around the world so as to meet the project's multilinguality requirements and, therefore, the exploration of a number of solutions. In fact, all categories of telemedical applications (audio and video conferencing, multimedia communications, flat file and image transfer with low-, medium-, and high-bandwidth data requirements) are considered, while the full range of network choices (digital land lines, cellular/wireless, satellite, and broadband) are being tested in terms of cost/performance tradeoffs that are inherent to them and the developmental stage each of these options occupies in their lifecycle. Finally, out of that, MERMAID utilizes advanced land-based line transmission technologies to aid the remote patient by making available the specialist care that is best suited in the particular case.

Information Exchange Automation in Maritime Transport

Directory of Open Access Journals (Sweden)

Zbigniew Pietrzykowski

2014-06-01

Full Text Available To ensure the safety of maritime transport the access to information must be provided through a commonly used services. However, an equally important task is to determine or agree on interpretation of incoming data and assessment of a current and predicted navigational situation and, in further step, intentions of the participants in the transport process. Thanks to the standardization of information format, automatic information exchange gets increasingly wider. Another step ahead is automatic interpretation of information and automation of negotiation processes - intelligent communication. Rapid development of IT and ICT technologies creates such opportunities. This article presents the results of research on a system of automatic communication and co-operation in maritime transport.

Improvement of Professional Training of Maritime Fleet Specialists: Experience of Interactive Technologies Introduction in the Danube Institute of National University «Odessa Maritime Academy»

Directory of Open Access Journals (Sweden)

Olga Demchenko

2016-08-01

Full Text Available The article focuses on the coverage of the most effective methods and technologies on improving communicative skills during the professional training of maritime fleet specialists. A complex study of skills formation process for communication in a foreign language in the Danube Institute of National University «Odessa Maritime Academy» has identified its the most problematic areas. In the result of using interactive technologies («brainstorming», project techniques, etc. was established positive dynamics in formation of skills of professional communication.

Multiquantum well beam-steering device for laser satellite communication

Science.gov (United States)

Lahat, Roee; Levy, Itamar; Shlomi, Arnon

2002-01-01

With the increasing interest in laser satellite communications, new methods are sought to solve the existing problems of accurate and rapid laser beam deflection. Current solutions in the form of galvanometers or piezo fast steering mirrors with one or two degrees of freedom are bulky, power-consuming and slow. The Multi-Quantum Well (MQW) is a semiconductor device with unique potential to steer laser beams without any moving parts. We have conducted a preliminary evaluation of the potential application of the MQW as a laser beam-steering device for laser satellite communication, examining the performance of critical parameters for this type of communications.

Satellite communications: possibilities and problems

International Nuclear Information System (INIS)

Hine, M.

1986-01-01

Communication links via satellites are becoming available in Europe, both as part of the development of the telephone system and as special services aimed at data traffic. They offer the possibility of speeds between 50 kb/s and 2 Mb/s, without the problems and long term commitments of long distance land lines. Such links are provided by the PTT's as circuits which can be booked for variable periods, and have error rates which can be very low and well controlled. Problems in networking can arise from the satellite delay, particularly if errors occur in the local connections, and from the leased circuit and tariff philosophies of the PTT's. (Auth.)

Vibration noise control in laser satellite communication

Science.gov (United States)

Saksonov, Avigdor; Shlomi, Arnon; Kopeika, Norman S.

2001-08-01

Laser satellite communication has become especially attractive in recent years. Because the laser beam width is narrow than in the RF or microwave range, the transmitted optical power may be significantly reduced. This leads to development of miniature communication systems with extremely low power consumption. On the other hand, the laser communication channel is very sensitive to vibrations of the optical platform. These vibrations cause angular noise in laser beam pointing, comparable to the laser beam width. As result, as significant portion of the optical power between transmitter and receiver is lost and the bit error rate is increased. Consequently, vibration noise control is a critical problem in laser satellite communication. The direction of the laser beam is corrected with a fast steering mirror (FSM). In this paper are presented two approaches for the FSM control. One is the feedback control that uses an LQG algorithm. The second is the direct feed- forward control when vibration noise is measured by three orthogonal accelerometers and drives directly the F SM. The performances of each approach are evaluated using MATLAB simulations.

Marine and maritime uses

Science.gov (United States)

1975-01-01

Activities related to: (1) understanding, controlling, and using the ocean's biological and physical processes for food and energy production and ship design purposes, and (2) providing navigation, communication, and data transmission technological aids which improve efficiency and enhance safety in maritime operations are disclosed.

78 FR 31576 - Enforcement Proceeding; Certain Two-Way Global Satellite Communication Devices, System and...

Science.gov (United States)

2013-05-24

...-Way Global Satellite Communication Devices, System and Components Thereof; Notice of Institution of... importation of certain two-way global satellite communication devices, system and components thereof by reason... importation any two-way global satellite communication devices, system, and components thereof that infringe...

Economic benefits of the Space Station to commercial communication satellite operators

Science.gov (United States)

Price, Kent M.; Dixson, John E.; Weyandt, Charles J.

1987-01-01

The economic and financial aspects of newly defined space-based activities, procedures, and operations (APOs) and associated satellite system designs are presented that have the potential to improve economic performance of future geostationary communications satellites. Launch insurance, launch costs, and the economics of APOs are examined. Retrieval missions and various Space Station scenarios are addressed. The potential benefits of the new APOs to the commercial communications satellite system operator are quantified.

Cybersecurity threats to satellite communications: Towards a typology of state actor responses

Science.gov (United States)

Housen-Couriel, Deborah

2016-11-01

Cybersecurity threats to satellite communications are a relatively new phenomenon, yet have quickly come to the forefront of concern for the sustainability of satellite systems due to the vulnerabilities that such threats may exploit and negatively impact. These vulnerabilities are mission-critical: they include launch systems, communications, telemetry, tracking and command, and mission completion. They and other aspects of satellite communications depend heavily on secure and resilient cyber capabilities for all stages of the satellite's lifespan. Because of the inherently global nature of both satellite and cyberspace activities, these capabilities rely significantly on international cooperation for setting a baseline of agreed legal norms that protect satellites and satellite communications. This critical cooperation is relevant during all mission phases, from planning to final wrap-up. Under optimal circumstances, the norms and standards protecting satellites and satellite transmissions are developed and enforced by those nation-state actors that are committed to system operability and overall mission sustainability for those satellites launched under their aegis and responsibility. However, when breaches of international law do occur in the form of hostile cyber events that cause damage to satellite communications, a range of measures should be available to the victim state, provided by the appropriate legal regime or regimes. This article proposes that a comprehensive and integrative multi-stakeholder review be undertaken in the near future of the measures available under international law for responding to hostile acts directed at satellite systems and communications, in a manner that takes into account both existing regimes of international law reviewed herein, as well as considerations of cybersecurity. These measures will depend upon the characterization of hostile interference with satellite transmissions in accordance with a proposed typology of

Deep space optical communication via relay satellite

Science.gov (United States)

Dolinar, S.; Vilnrotter, V.; Gagliardi, R.

1981-01-01

The application of optical communications for a deep space link via an earth-orbiting relay satellite is discussed. The system uses optical frequencies for the free-space channel and RF links for atmospheric transmission. The relay satellite is in geostationary orbit and contains the optics necessary for data processing and formatting. It returns the data to earth through the RF terrestrial link and also transmits an optical beacon to the satellite for spacecraft return pointing and for the alignment of the transmitting optics. Future work will turn to modulation and coding, pointing and tracking, and optical-RF interfacing.

Satellite switched FDMA advanced communication technology satellite program

Science.gov (United States)

Atwood, S.; Higton, G. H.; Wood, K.; Kline, A.; Furiga, A.; Rausch, M.; Jan, Y.

1982-01-01

The satellite switched frequency division multiple access system provided a detailed system architecture that supports a point to point communication system for long haul voice, video and data traffic between small Earth terminals at Ka band frequencies at 30/20 GHz. A detailed system design is presented for the space segment, small terminal/trunking segment at network control segment for domestic traffic model A or B, each totaling 3.8 Gb/s of small terminal traffic and 6.2 Gb/s trunk traffic. The small terminal traffic (3.8 Gb/s) is emphasized, for the satellite router portion of the system design, which is a composite of thousands of Earth stations with digital traffic ranging from a single 32 Kb/s CVSD voice channel to thousands of channels containing voice, video and data with a data rate as high as 33 Mb/s. The system design concept presented, effectively optimizes a unique frequency and channelization plan for both traffic models A and B with minimum reorganization of the satellite payload transponder subsystem hardware design. The unique zoning concept allows multiple beam antennas while maximizing multiple carrier frequency reuse. Detailed hardware design estimates for an FDMA router (part of the satellite transponder subsystem) indicate a weight and dc power budget of 353 lbs, 195 watts for traffic model A and 498 lbs, 244 watts for traffic model B.

Mission studies on constellation of LEO satellites with remote-sensing and communication payloads

Science.gov (United States)

Chen, Chia-Ray; Hwang, Feng-Tai; Hsueh, Chuang-Wei

2017-09-01

Revisiting time and global coverage are two major requirements for most of the remote sensing satellites. Constellation of satellites can get the benefit of short revisit time and global coverage. Typically, remote sensing satellites prefer to choose Sun Synchronous Orbit (SSO) because of fixed revisiting time and Sun beta angle. The system design and mission operation will be simple and straightforward. However, if we focus on providing remote sensing and store-and-forward communication services for low latitude countries, Sun Synchronous Orbit will not be the best choice because we need more satellites to cover the communication service gap in low latitude region. Sometimes the design drivers for remote sensing payloads are conflicted with the communication payloads. For example, lower orbit altitude is better for remote sensing payload performance, but the communication service zone will be smaller and we need more satellites to provide all time communication service. The current studies focus on how to provide remote sensing and communication services for low latitude countries. A cost effective approach for the mission, i.e. constellation of microsatellites, will be evaluated in this paper.

Medical image transmission via communication satellite. Evaluation of bone scintigraphy

International Nuclear Information System (INIS)

Suzuki, Hideki; Inoue, Tomio; Endo, Keigo; Shimamoto, Shigeru.

1995-01-01

As compared with terrestrial circuits, the communication satellite possesses superior characteristics such as wide area coverage, broadcasting, high capacity, and robustness to disasters. Utilizing the narrow band channel (64 kbps) of the geostationary satellite JCSAT 1 located at the altitude of 36,000 km above the equator, the authors investigated satellite-relayed medical imagings by video signals, with bone scintigraphy as a model. Each bone scintigraphy was taken by a handy-video camera, digitalized and transmitted from faculty of technology located at 25 kilometers apart from our department. Clear bone scintigraphy was obtained via satellite, as seen on the view box. Eight nuclear physicians evaluated 20 cases of bone scintigraphy. ROC (Receiver Operating Characteristic) analysis was performed between the scintigraphies on view box and via satellite by the rating method. The area under the ROC curve was 91.6±2.6% via satellite, and 93.2±2.4% on the view box and there was no significant difference between them. These results suggest that the satellite communication is very useful and effective system to send nuclear imagings to distant institutes. (author)

[Medical image transmission via communication satellite: evaluation of bone scintigraphy].

Science.gov (United States)

Suzuki, H; Inoue, T; Endo, K; Shimamoto, S

1995-10-01

As compared with terrestrial circuits, the communication satellite possesses superior characteristics such as wide area coverage, broadcasting, high capacity, and robustness to disasters. Utilizing the narrow band channel (64 kbps) of the geostationary satellite JCSAT1 located at the altitude of 36,000 km above the equator, the authors investigated satellite-relayed medical images by video signals, with bone scintigraphy as a model. Each bone scintigraphy was taken by a handy-video camera, digitalized and transmitted from faculty of technology located at 25 kilometers apart from our department. Clear bone scintigraphy was obtained via satellite, as seen on the view box. Eight nuclear physicians evaluated 20 cases of bone scintigraphy. ROC (Receiver Operating Characteristic) analysis was performed between the scintigraphies on view box and via satellite by the rating method. The area under the ROC curve was 91.6 +/- 2.6% via satellite, and 93.2 +/- 2.4% on the view box and there was no significant difference between them. These results suggest that the satellite communication is very useful and effective system to send nuclear imagings to distant institutes.

Advanced Oil Spill Detection Algorithms For Satellite Based Maritime Environment Monitoring

Science.gov (United States)

Radius, Andrea; Azevedo, Rui; Sapage, Tania; Carmo, Paulo

2013-12-01

During the last years, the increasing pollution occurrence and the alarming deterioration of the environmental health conditions of the sea, lead to the need of global monitoring capabilities, namely for marine environment management in terms of oil spill detection and indication of the suspected polluter. The sensitivity of Synthetic Aperture Radar (SAR) to the different phenomena on the sea, especially for oil spill and vessel detection, makes it a key instrument for global pollution monitoring. The SAR performances in maritime pollution monitoring are being operationally explored by a set of service providers on behalf of the European Maritime Safety Agency (EMSA), which has launched in 2007 the CleanSeaNet (CSN) project - a pan-European satellite based oil monitoring service. EDISOFT, which is from the beginning a service provider for CSN, is continuously investing in R&D activities that will ultimately lead to better algorithms and better performance on oil spill detection from SAR imagery. This strategy is being pursued through EDISOFT participation in the FP7 EC Sea-U project and in the Automatic Oil Spill Detection (AOSD) ESA project. The Sea-U project has the aim to improve the current state of oil spill detection algorithms, through the informative content maximization obtained with data fusion, the exploitation of different type of data/ sensors and the development of advanced image processing, segmentation and classification techniques. The AOSD project is closely related to the operational segment, because it is focused on the automation of the oil spill detection processing chain, integrating auxiliary data, like wind information, together with image and geometry analysis techniques. The synergy between these different objectives (R&D versus operational) allowed EDISOFT to develop oil spill detection software, that combines the operational automatic aspect, obtained through dedicated integration of the processing chain in the existing open source NEST

Modeling and Performance Analysis of 10 Gbps Inter-satellite Optical Wireless Communication Link

Science.gov (United States)

Singh, Mehtab

2017-12-01

Free-space optical (FSO) communication has the advantages of two of the most predominant data transmission technologies - optical fiber communication and wireless communication. Most of the technical aspects of FSO are similar to that of optical fiber communication, with major difference in the information signal propagation medium which is free space in case of FSO rather than silica glass in optical fiber communication. One of the most important applications of FSO is inter-satellite optical wireless communication (IsOWC) links which will be deployed in the future in space. The IsOWC links have many advantages over the previously existing microwave satellite communication technologies such as higher bandwidth, lower power consumption, low cost of implementation, light size, and weight. In this paper, modeling and performance analysis of a 10-Gbps inter-satellite communication link with two satellites separated at a distance of 1,200 km has been done using OPTISYSTEM simulation software. Performance has been analyzed on the basis of quality factor, signal to noise ratio (SNR), and total power of the received signal.

College curriculum-sharing via CTS. [Communications Technology Satellite

Science.gov (United States)

Hudson, H. E.; Guild, P. D.; Coll, D. C.; Lumb, D. R.

1975-01-01

Domestic communication satellites and video compression techniques will increase communication channel capacity and reduce cost of video transmission. NASA Ames Research Center, Stanford University and Carleton University are participants in an experiment to develop, demonstrate, and evaluate college course sharing techniques via satellite using video compression. The universities will exchange televised seminar and lecture courses via CTS. The experiment features real-time video compression with channel coding and quadra-phase modulation for reducing transmission bandwidth and power requirements. Evaluation plans and preliminary results of Carleton surveys on student attitudes to televised teaching are presented. Policy implications for the U.S. and Canada are outlined.

47 CFR 80.54 - Automated Maritime Telecommunications System (AMTS)-System Licensing.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Automated Maritime Telecommunications System (AMTS)-System Licensing. 80.54 Section 80.54 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... § 80.54 Automated Maritime Telecommunications System (AMTS)—System Licensing. AMTS licensees will be...

Estimating Effects Of Rain On Ground/Satellite Communication

Science.gov (United States)

Manning, R. M.

1992-01-01

LeRC-SLAM provides static and dynamic statistical assessment of impact of attenuation by rain on communication link established between Earth terminal and geosynchronous satellite. Program designed for use in specification, design, and assessment of satellite link for any terminal location in continental United States. IBM PC version written in Microsoft QuickBASIC, and Macintosh version written in Microsoft Basic.

Advanced Communication Technology Satellite (ACTS) multibeam antenna technology verification experiments

Science.gov (United States)

Acosta, Roberto J.; Larko, Jeffrey M.; Lagin, Alan R.

1992-01-01

The Advanced Communication Technology Satellite (ACTS) is a key to reaching NASA's goal of developing high-risk, advanced communications technology using multiple frequency bands to support the nation's future communication needs. Using the multiple, dynamic hopping spot beams, and advanced on board switching and processing systems, ACTS will open a new era in communications satellite technology. One of the key technologies to be validated as part of the ACTS program is the multibeam antenna with rapidly reconfigurable hopping and fixed spot beam to serve users equipped with small-aperature terminals within the coverage areas. The proposed antenna technology experiments are designed to evaluate in-orbit ACTS multibeam antenna performance (radiation pattern, gain, cross pol levels, etc.).

Modular approach for satellite communication ground terminals

Science.gov (United States)

Gould, G. R.

1984-01-01

The trend in satellite communications is toward completely digital, time division multiple access (TDMA) systems with uplink and downlink data rates dictated by the type of service offered. Trunking terminals will operate in the 550 MBPS (megabit per second) region uplink and downlink, whereas customer premise service (CPS) terminals will operate in the 25 to 10 MBPS region uplink and in the 200 MBPS region downlink. Additional criteria for the ground terminals will be to maintain clock sychronization with the system and burst time integrity to within a matter of nanoseconds, to process required order-fire information, to provide adaptive data scrambing, and to compensate for variations in the user input output data rates, and for changes in range in the satellite communications links resulting from satellite perturbations in orbit. To achieve the required adaptability of a ground terminal to the above mentioned variables, programmable building blocks can be developed that will meet all of these requirements. To maintain system synchronization, i.e., all bursted data arriving at the satellite within assigned TDMA windows, ground terminal transmit data rates and burst timing must be maintained within tight tolerances. With a programmable synchronizer as the heart of the terminal timing generation, variable data rates and burst timing tolerances are achievable. In essence, the unit inputs microprocessor generated timing words and outputs discrete timing pulses.

Advanced domestic digital satellite communications systems experiments

Science.gov (United States)

Iso, A.; Izumisawa, T.; Ishida, N.

1984-02-01

The characteristics of advanced digital transmission systems were measured, using newly developed small earth stations and a K-band and C-band communication satellite. Satellite link performance for data, facsimile, video and packet switching information transmission at bit rates ranging from 6.4 kbit/s to 6.3 Mbit/s have been confirmed, using a small K-band earth station and a demand-assignment time division multiple access system. A low-capacity omni-use C-band terminal experiment has verified a telephone channel transmission performance by spread-spectrum multiple access. Single point to multipoint transmission characteristics of the 64 kbit/s data signals from the computer center were tested, using a receive-only 4 GHz earth terminal. Basic satellite link performance was confirmed under clear-sky conditions. Precise satellite orbit and attitude keeping experiments were carried out to obtain precise satellite antenna pointing accuracy for development of K-band earth stations that do not require satellite tracking equipment. Precise station keeping accuracy of 0.02 degrees was obtained.

An introduction to the Research Innovation and Knowledge Management Roadmap for the South African Maritime Sector

CSIR Research Space (South Africa)

Funke, Nicola S

2017-04-01

Full Text Available OBJECTIVES & ACTIONS We have a maritime culture and recognise and learn from our maritime history 1 Foster national maritime pride 3 Develop and communicate a co-authored discourse on South Africa’s maritime history 2 Support maritime historical... and training facilities 6 Build and retain skills in the maritime sector 2 Support and develop maritime-focused technology and innovation 7 OBJECTIVES & ACTIONS Conduct humanities and social science research on pertinent issues 3 Create knowledge...

47 CFR 80.653 - Scope of communications.

Science.gov (United States)

2010-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Maritime Support Stations § 80.653 Scope of communications. (a) Maritime support stations...) Maritime support stations are authorized to conduct the following operations: (1) Training of personnel in...

The ACTS Flight System - Cost-Effective Advanced Communications Technology. [Advanced Communication Technology Satellite

Science.gov (United States)

Holmes, W. M., Jr.; Beck, G. A.

1984-01-01

The multibeam communications package (MCP) for the Advanced Communications Technology Satellite (ACTS) to be STS-launched by NASA in 1988 for experimental demonstration of satellite-switched TDMA (at 220 Mbit/sec) and baseband-processor signal routing (at 110 or 27.5 Mbit/sec) is characterized. The developmental history of the ACTS, the program definition, and the spacecraft-bus and MCP parameters are reviewed and illustrated with drawings, block diagrams, and maps of the coverage plan. Advanced features of the MPC include 4.5-dB-noise-figure 30-GHz FET amplifiers and 20-GHz TWTA transmitters which provide either 40-W or 8-W RF output, depending on rain conditions. The technologies being tested in ACTS can give frequency-reuse factors as high as 20, thus greatly expanding the orbit/spectrum resources available for U.S. communications use.

Key issues of multiple access technique for LEO satellite communication systems

Institute of Scientific and Technical Information of China (English)

温萍萍; 顾学迈

2004-01-01

The large carrier frequency shift caused by the high-speed movement of satellite (Doppler effects) and the propagation delay on the up-down link are very critical issues in an LEO satellite communication system, which affects both the selection and the implementation of a suitable access method. A Doppler based multiple access technique is used here to control the flow and an MPRMA-HS protocol is proposed for the application in LEO satellite communication systems. The extended simulation trials prove that the proposed scheme seems to be a very promising access method.

Study to forecast and determine characteristics of world satellite communications market

Science.gov (United States)

Filep, R. T.; Schnapf, A.; Fordyce, S. W.

1983-01-01

The world commercial communications satellite market during the spring and summer of 1983 was examined and characteristics and forecasts of the market extending to the year 2000 were developed. Past, present and planned satellites were documented in relation to frequencies, procurement and launch dates, costs, transponders, and prime contractor. Characteristics of the market are outlined for the periods 1965 - 1985, 1986 - 1989, and 1990 - 2000. Market share forecasts, discussions of potential competitors in various world markets, and profiles of major communication satellite manufacturing and user countries are documented.

TWT design requirements for 30/20 GHz digital communications' satellite

Science.gov (United States)

Stankiewicz, N.; Anzic, G.

1979-01-01

The rapid growth of communication traffic (voice, data, and video) requires the development of additional frequency bands before the 1990's. The frequencies currently in use for satellite communications at 6/4 GHz are crowded and demands for 14/12 GHz systems are increasing. Projections are that these bands will be filled to capacity by the late 1980's. The next higher frequency band allocated for satellite communications is at 30/20 GHz. For interrelated reasons of efficiency, power level, and system reliability criteria, a candidate for the downlink amplifier in a 30/20 GHz communications' satellite is a dual mode traveling wave tube (TWT) equipped with a highly efficient depressed collector. A summary is given of the analyses which determine the TWT design requirements. The overall efficiency of such a tube is then inferred from a parametric study and from experimental data on multistaged depressed collectors. The expected TWT efficiency at 4 dB below output saturation is 24 percent in the high mode and 22 percent in the low mode.

Antennas for mobile satellite communications

Science.gov (United States)

Huang, John

1991-12-01

A NASA sponsored program, called the Mobile Satellite (MSAT) system, has prompted the development of several innovative antennas at L-band frequencies. In the space segment of the MSAT system, an efficient, light weight, circularly polarized microstrip array that uses linearly polarized elements was developed as a multiple beam reflector feed system. In the ground segment, a low-cost, low-profile, and very efficient microstrip Yagi array was developed as a medium-gain mechanically steered vehicle antenna. Circularly shaped microstrip patches excited at higher-order modes were also developed as low-gain vehicle antennas. A more recent effort called for the development of a 20/30 GHz mobile terminal antenna for future-generation mobile satellite communications. To combat the high insertion loss encountered at 20/30 GHz, series-fed Monolithic Microwave Integrated Circuit (MMIC) microstrip array antennas are currently being developed. These MMIC arrays may lead to the development of several small but high-gain Ka-band antennas for the Personal Access Satellite Service planned for the 2000s.

A demand assignment control in international business satellite communications network

Science.gov (United States)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio; Hirata, Yasuo

An experimental system is being developed for use in an international business satellite (IBS) communications network based on demand-assignment (DA) and TDMA techniques. This paper discusses its system design, in particular from the viewpoints of a network configuration, a DA control, and a satellite channel-assignment algorithm. A satellite channel configuration is also presented along with a tradeoff study on transmission rate, HPA output power, satellite resource efficiency, service quality, and so on.

Mass Processing of Sentinel-1 Images for Maritime Surveillance

Directory of Open Access Journals (Sweden)

Carlos Santamaria

2017-07-01

Full Text Available The free, full and open data policy of the EU’s Copernicus programme has vastly increased the amount of remotely sensed data available to both operational and research activities. However, this huge amount of data calls for new ways of accessing and processing such “big data”. This paper focuses on the use of Copernicus’s Sentinel-1 radar satellite for maritime surveillance. It presents a study in which ship positions have been automatically extracted from more than 11,500 Sentinel-1A images collected over the Mediterranean Sea, and compared with ship position reports from the Automatic Identification System (AIS. These images account for almost all the Sentinel-1A acquisitions taken over the area during the two-year period from the start of the operational phase in October 2014 until September 2016. A number of tools and platforms developed at the European Commission’s Joint Research Centre (JRC that have been used in the study are described in the paper. They are: (1 Search for Unidentified Maritime Objects (SUMO, a tool for ship detection in Synthetic Aperture Radar (SAR images; (2 the JRC Earth Observation Data and Processing Platform (JEODPP, a platform for efficient storage and processing of large amounts of satellite images; and (3 Blue Hub, a maritime surveillance GIS and data fusion platform. The paper presents the methodology and results of the study, giving insights into the new maritime surveillance knowledge that can be gained by analysing such a large dataset, and the lessons learnt in terms of handling and processing the big dataset.

A digital simulation of message traffic for natural disaster warning communications satellite

Science.gov (United States)

Hein, G. F.; Stevenson, S. M.

1972-01-01

Various types of weather communications are required to alert industries and the general public about the impending occurrence of tornados, hurricanes, snowstorms, floods, etc. A natural disaster warning satellite system has been proposed for meeting the communications requirements of the National Oceanic and Atmospheric Administration. Message traffic for a communications satellite was simulated with a digital computer in order to determine the number of communications channels to meet system requirements. Poisson inputs are used for arrivals and an exponential distribution is used for service.

ESA personal communications and digital audio broadcasting systems based on non-geostationary satellites

Science.gov (United States)

Logalbo, P.; Benedicto, J.; Viola, R.

1993-01-01

Personal Communications and Digital Audio Broadcasting are two new services that the European Space Agency (ESA) is investigating for future European and Global Mobile Satellite systems. ESA is active in promoting these services in their various mission options including non-geostationary and geostationary satellite systems. A Medium Altitude Global Satellite System (MAGSS) for global personal communications at L and S-band, and a Multiregional Highly inclined Elliptical Orbit (M-HEO) system for multiregional digital audio broadcasting at L-band are described. Both systems are being investigated by ESA in the context of future programs, such as Archimedes, which are intended to demonstrate the new services and to develop the technology for future non-geostationary mobile communication and broadcasting satellites.

The new Euskalmet coastal-maritime warning system

Science.gov (United States)

Gaztelumendi, Santiago; Egaña, Joseba; Liria, Pedro; Gonzalez, Manuel; Aranda, José Antonio; Anitua, Pedro

2016-06-01

This work presents the main characteristics of the Basque Meteorology Agency (Euskalmet) maritime-coastal risk warning system, with special emphasis on the latest updates, including a clear differentiation on specific warning messages addressing sea conditions for navigation purposes in the first 2 nautical miles, and expected coastal impacts. Some details of the warning bulletin for maritime and coastal risk situations are also presented, together with other communication products and strategies used in coastal and maritime severe episodes at the Basque coast. Today, three different aspects are included in the coastal-maritime risk warning system in Basque Country, related to the main potential severe events that affecting coastal activities. - "Galerna" risk relates to a sudden wind reversal that can severely affect coastal navigation and recreational activities. - "Navigation" risk relates to severe sea state conditions for 0-2 miles, affecting different navigation activities. - "Coastal impact" risk relates to adverse wave characteristics and tidal surges that induce flooding events and different impacts in littoral areas.

77 FR 58579 - Certain Two-Way Global Satellite Communication Devices, System and Components Thereof...

Science.gov (United States)

2012-09-21

... Communication Devices, System and Components Thereof; Institution of Investigation Pursuant to 19 U.S.C. 1337... certain two-way global satellite communication devices, system and components thereof that infringe one or... within the United States after importation of certain two-way global satellite communication devices...

Communications Satellite Systems Conference, 9th, San Diego, CA, March 7-11, 1982, Collection of Technical Papers

Science.gov (United States)

The Shuttle-to-Geostationary Orbital Transfer by mid-level thrust is considered along with multibeam antenna concepts for global communications, the antenna pointing systems for large communication satellites, the connection phase of multidestination protocols for broadcast satellites, and an experiment in high-speed international packet switching. Attention is given to a dynamic switch matrix for the TDMA satellite switching system, the characterization of 16 bit microprocessors for space use, in-orbit operation and test of Intelsat V satellites, the first operational communications system via satellite in Europe, the Arab satellite communications systems, second generation business satellite systems for Europe, and a high performance Ku-band satellite for the 1980's. Other topics investigated are related to Ku-band terminal design tradeoffs, progress in the definition of the Italian satellite for domestic telecommunications, future global satellite systems for Intelsat, and satellite refuelling in orbit.

Communication Media and Educational Technology: An Overview and Assessment with Reference to Communication Satellites.

Science.gov (United States)

Ohlman, Herbert

In this survey and analysis of the present state and future trends of communication media and educational technology, particular emphasis is placed on the potential uses of communication satellites and the substitution of electronic transmission for physical distribution of educational materials. The author analyzes in detail the characteristics…

Investigation of multipactor breakdown in communication satellite

Indian Academy of Sciences (India)

Multipactor breakdown or multipactor discharge is a form of high frequency discharge that may occur in microwave components operating at very low pressures. Some RF components of multi-channel communication satellites have co-axial geometry and handle high RF power under near-vacuum conditions.

A Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

Directory of Open Access Journals (Sweden)

Jong Won Eun

2000-12-01

Full Text Available It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifetime. This paper concentrates on the fuel estimation method that was studied for calculation of the propellant budget by using the given algorithms. Applications of this method are discussed for a communication and broadcasting satellite.

Spectrum and power allocation in cognitive multi-beam satellite communications with flexible satellite payloads

Science.gov (United States)

Liu, Zhihui; Wang, Haitao; Dong, Tao; Yin, Jie; Zhang, Tingting; Guo, Hui; Li, Dequan

2018-02-01

In this paper, the cognitive multi-beam satellite system, i.e., two satellite networks coexist through underlay spectrum sharing, is studied, and the power and spectrum allocation method is employed for interference control and throughput maximization. Specifically, the multi-beam satellite with flexible payload reuses the authorized spectrum of the primary satellite, adjusting its transmission band as well as power for each beam to limit its interference on the primary satellite below the prescribed threshold and maximize its own achievable rate. This power and spectrum allocation problem is formulated as a mixed nonconvex programming. For effective solving, we first introduce the concept of signal to leakage plus noise ratio (SLNR) to decouple multiple transmit power variables in the both objective and constraint, and then propose a heuristic algorithm to assign spectrum sub-bands. After that, a stepwise plus slice-wise algorithm is proposed to implement the discrete power allocation. Finally, simulation results show that adopting cognitive technology can improve spectrum efficiency of the satellite communication.

Worldwide satellite communications for the energy utility industry. Final report

International Nuclear Information System (INIS)

Skelton, R.L.

1998-07-01

Recent and future generations of low earth orbiting (LEO) satellites are promising new possibilities for using space communications to achieve operational improvements and business expansion in energy supply and delivery industries. The ability to reach remote locations with relatively inexpensive devices and infrastructure is a unique property of satellites. Applications include remote monitoring and control of distributed resources and emergency and personal communication. Satellite systems are emerging as a significant opportunity for investment minded utilities. Over a dozen groups are planning to launch a total of 1200 LEOs in the period from 1996 to 2006, at a probable cost of over $20 Billion. This large number of systems can provide a worldwide mix of narrow band and wideband services including data, voice, video and Internet access. This paper examines the two primary factors which have limited applications in the energy industry: cost and propagation delay. The former has so far limited the technology to fixed communications with a few important sites such as remote substations. The latter has rendered the technology unsuitable for applications where critical protection mechanisms are involved. These constraints are effectively countered by the emerging LEO systems. Big LEOs will be used for voice service, little LEOs will be the systems of choice for most utility data applications. The author concludes that there are good technical and business reasons to reconsider future satellite communications as an option for meeting certain strategic business objectives in power system management and customer oriented information services

22 CFR 123.27 - Special licensing regime for export to U.S. allies of commercial communications satellite...

Science.gov (United States)

2010-04-01

.... allies of commercial communications satellite components, systems, parts, accessories, attachments and... export to U.S. allies of commercial communications satellite components, systems, parts, accessories... associated technical data for commercial communications satellites, and who are so registered with the...

Advances in satellite communications

CERN Document Server

Minoli, Daniel

2015-01-01

Discussing advances in modulation techniques and HTS spotbeam technologiesSurveying emerging high speed aeronautical mobility services and maritime and other terrestrial mobility servicesAssessing M2M (machine-to-machine) applications, emerging Ultra HD video technologies and new space technology

LEOPACK The integrated services communications system based on LEO satellites

Science.gov (United States)

Negoda, A.; Bunin, S.; Bushuev, E.; Dranovsky, V.

LEOPACK is yet another LEO satellite project which provides global integrated services for 'business' communications. It utilizes packet rather then circuit switching in both terrestrial and satellite chains as well as cellular approach for frequencies use. Original multiple access protocols and decentralized network control make it possible to organize regionally or logically independent and world-wide networks. Relatively small number of satellites (28) provides virtually global network coverage.

Identifying Maritime Logistics Competences for Sustaining Maritime Economies

DEFF Research Database (Denmark)

Gammelgaard, Britta; Kinra, Aseem; Sornn-Friese, Henrik

This paper conducts a comparative assessment of the Danish maritime cluster, measured against a range of international known and respected maritime clusters like Virginia, London, the Netherlands, Singapore, Shanghai, Norway and Hong Kong. The aim is also to bring out the characteristics of the D......This paper conducts a comparative assessment of the Danish maritime cluster, measured against a range of international known and respected maritime clusters like Virginia, London, the Netherlands, Singapore, Shanghai, Norway and Hong Kong. The aim is also to bring out the characteristics...... of the Danish maritime cluster’s development, and unique competences. The comparative assessment highlights the importance of different historical and geographical backgrounds, when explaining the relative positions of the Danish, and other comparable maritime clusters. Other specific common features...

Development of a demand assignment/TDMA system for international business satellite communications

Science.gov (United States)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio; Hirata, Yasuo; Yamazaki, Yoshiharu

An experimental IBS (international business satellite) communications system based on a demand assignment and TDMA (time-division multiple-access) operation has been developed. The system utilizes a limited satellite resource efficiently and provides various kinds of ISDN services totally. A discussion is presented of the IBS network configurations suitable to international communications and describes the developed communications system from the viewpoint of the hardware and software implementation. The performance in terms of the transmission quality and call processing is also demonstrated.

IMT-2000 Satellite Standards with Applications to Mobile Air Traffic Communications Networks

Science.gov (United States)

Shamma, Mohammed A.

2004-01-01

The International Mobile Telecommunications - 2000 (IMT-2000) standard and more specifically the Satellite component of it, is investigated as a potential alternative for communications to aircraft mobile users en-route and in terminal area. Its application to Air Traffic Management (ATM) communication needs is considered. A summary of the specifications of IMT-2000 satellite standards are outlined. It is shown via a system research analysis that it is possible to support most air traffic communication needs via an IMT-2000 infrastructure. This technology can compliment existing, or future digital aeronautical communications technologies such as VDL2, VDL3, Mode S, and UAT.

Software defined radio (SDR) architecture for concurrent multi-satellite communications

Science.gov (United States)

Maheshwarappa, Mamatha R.

SDRs have emerged as a viable approach for space communications over the last decade by delivering low-cost hardware and flexible software solutions. The flexibility introduced by the SDR concept not only allows the realisation of concurrent multiple standards on one platform, but also promises to ease the implementation of one communication standard on differing SDR platforms by signal porting. This technology would facilitate implementing reconfigurable nodes for parallel satellite reception in Mobile/Deployable Ground Segments and Distributed Satellite Systems (DSS) for amateur radio/university satellite operations. This work outlines the recent advances in embedded technologies that can enable new communication architectures for concurrent multi-satellite or satellite-to-ground missions where multi-link challenges are associated. This research proposes a novel concept to run advanced parallelised SDR back-end technologies in a Commercial-Off-The-Shelf (COTS) embedded system that can support multi-signal processing for multi-satellite scenarios simultaneously. The initial SDR implementation could support only one receiver chain due to system saturation. However, the design was optimised to facilitate multiple signals within the limited resources available on an embedded system at any given time. This was achieved by providing a VHDL solution to the existing Python and C/C++ programming languages along with parallelisation so as to accelerate performance whilst maintaining the flexibility. The improvement in the performance was validated at every stage through profiling. Various cases of concurrent multiple signals with different standards such as frequency (with Doppler effect) and symbol rates were simulated in order to validate the novel architecture proposed in this research. Also, the architecture allows the system to be reconfigurable by providing the opportunity to change the communication standards in soft real-time. The chosen COTS solution provides a

In-Space Internet-Based Communications for Space Science Platforms Using Commercial Satellite Networks

Science.gov (United States)

Kerczewski, Robert J.; Bhasin, Kul B.; Fabian, Theodore P.; Griner, James H.; Kachmar, Brian A.; Richard, Alan M.

1999-01-01

The continuing technological advances in satellite communications and global networking have resulted in commercial systems that now can potentially provide capabilities for communications with space-based science platforms. This reduces the need for expensive government owned communications infrastructures to support space science missions while simultaneously making available better service to the end users. An interactive, high data rate Internet type connection through commercial space communications networks would enable authorized researchers anywhere to control space-based experiments in near real time and obtain experimental results immediately. A space based communications network architecture consisting of satellite constellations connecting orbiting space science platforms to ground users can be developed to provide this service. The unresolved technical issues presented by this scenario are the subject of research at NASA's Glenn Research Center in Cleveland, Ohio. Assessment of network architectures, identification of required new or improved technologies, and investigation of data communications protocols are being performed through testbed and satellite experiments and laboratory simulations.

INVESTIGATION OF ADS-B MESSAGES TRAFFIC VIA SATELLITE COMMUNICATION CHANNEL

Directory of Open Access Journals (Sweden)

Volodymyr Kharchenko

2014-12-01

Full Text Available For modelling of ADS-B messages transmition with the help of low-orbit satellite complex Іrіdіumdifferent models of communication channel "Aircraft-to-Satellites-to-Ground Stations" were built using NetCrackerProfessіonal 4.1 software. Influence of aircraft and satellites amount on average link utilization and message travellingtime was studied for telecommunication channels with intersatellite link and bent-pipe architecture. The effect ofcommunication channel "saturation" during simultaneous data transmission through a satellite communicationchannel from many planes was investigated.

Evaluation of spacecraft technology programs (effects on communication satellite business ventures), volume 1

Science.gov (United States)

Greenburg, J. S.; Gaelick, C.; Kaplan, M.; Fishman, J.; Hopkins, C.

1985-01-01

Commercial organizations as well as government agencies invest in spacecraft (S/C) technology programs that are aimed at increasing the performance of communications satellites. The value of these programs must be measured in terms of their impacts on the financial performane of the business ventures that may ultimately utilize the communications satellites. An economic evaluation and planning capability was developed and used to assess the impact of NASA on-orbit propulsion and space power programs on typical fixed satellite service (FSS) and direct broadcast service (DBS) communications satellite business ventures. Typical FSS and DBS spin and three-axis stabilized spacecraft were configured in the absence of NASA technology programs. These spacecraft were reconfigured taking into account the anticipated results of NASA specified on-orbit propulsion and space power programs. In general, the NASA technology programs resulted in spacecraft with increased capability. The developed methodology for assessing the value of spacecraft technology programs in terms of their impact on the financial performance of communication satellite business ventures is described. Results of the assessment of NASA specified on-orbit propulsion and space power technology programs are presented for typical FSS and DBS business ventures.

INVESTIGATION OF ADS-B MESSAGES TRAFFIC VIA SATELLITE COMMUNICATION CHANNEL

OpenAIRE

Volodymyr Kharchenko; Wang Bo; Andrii Grekhov; Marina Kovalenko

2014-01-01

For modelling of ADS-B messages transmition with the help of low-orbit satellite complex Іrіdіumdifferent models of communication channel "Aircraft-to-Satellites-to-Ground Stations" were built using NetCrackerProfessіonal 4.1 software. Influence of aircraft and satellites amount on average link utilization and message travellingtime was studied for telecommunication channels with intersatellite link and bent-pipe architecture. The effect ofcommunication channel "saturation" during simultaneou...

Satellite communication transponders and their reliability; Eisei tosai tsushin kiki oyobi shinraisei ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Ogawa, H [NTT Wireless System Laboratories, Kanagawa (Japan)

1994-11-01

The Engineering Test Satellite-VI is a large composite test satellite weighing two tons to perform different communication experiments. Adoption of the multi-beam satellite communication system has made possible to increase the transmission capacity, reduce the sizes of earth stations, and utilize frequencies more effectively. This paper describes the configuration of the relaying devices mounted thereon, the newly developed circuit technologies, and their reliability. The multi-beam satellite communication system mounts a number of transponders, with the frequency bands used divided into the 2.6/2.5 GHz band between the moving body and the satellite, the 6/4 GHz band for the channels between the earth stations and the satellite, and the 30/20 GHz band for the fixed communications. These arrangements were intended to achieve large size reduction as a result of applying the integrated circuit technology. The transmitters and the receivers corresponding to each beam are connected by using the satellite switches (16 inputs {times} 12 outputs). The parts used were general purpose ones rather than those specified in the MIL standards because of their number having reached so huge. Their reliability was ensured by long-term burn-in operations. 5 refs., 6 figs., 1 tab.

First satellite mobile communication trials using BLQS-CDMA

Science.gov (United States)

Luzdemateo, Maria; Johns, Simon; Dothey, Michel; Vanhimbeeck, Carl; Deman, Ivan; Wery, Bruno

1993-01-01

In this paper, technical results obtained in the first MSBN Land mobile technical trial are reported. MSBN (Mobile Satellite Business Network) is a new program undertaken by the European Space Agency (ESA) to promote mobile satellite communication in Europe, in particular voice capability. The first phase of the MSBN system implementation plan is an experimental phase. Its purpose is to evaluate through field experiments the performance of the MSBN system prior to finalization of its specifications. Particularly, the objective is to verify in the field and possibly improve the performance of the novel satellite access technique BLQS-CDMA (Band Limited Quasi-Synchronous-Code Division Multiple Access), which is proposed as baseline for the MSBN.

47 CFR 80.1127 - On-scene communications.

Science.gov (United States)

2010-10-01

....1127 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating Procedures for Distress and Safety Communications § 80.1127 On-scene communications. (a) On-scene communications...

Revision of IMO Model Course 3.17 Maritime English. Focus on Maritime English to Auxiliary Personnel

Directory of Open Access Journals (Sweden)

L. Martes

2015-09-01

Full Text Available Under the Manila 2010 amendments to the STCW , all crew members on board cruise vessels, mainly those assisting passengers during emergency situations and not only, “should be able to communicate safety-related issues in English or in the language spoken by the passengers and other personnel on board.” Having in view that navigational and safety communications from ship to shore and vice versa, ship to ship, and on board ships must be precise, simple and unambiguous, so as to avoid confusion and error, besides the need to standardize the language used, there is a growing demand of developing communication skills in English, especially for personnel working on cruise vessels, but also on RORO vessels, yachts and small passenger vessels. This is the reason why we have designed, developed and are already delivering the “Maritime English for Auxiliary Personnel" course in Specialized Maritime English to auxiliary personnel working on board cruise vessels to develop their ability to communicate with passengers, mainly during an emergency. The course covers the specific language used to describe the parts of ships, organisation on board ships, all essential safety-related matters and work-specific topics. It also reflects the situations in which auxiliary personnel need to communicate, with each other, with other crew members and with shore side authorities. The final goal of this course is to improve fluency in spoken English in real life situations which, of course, can be both routine and non-routine.

Application of communications satellites to educational development. [technology utilization/information systems - bibliographies

Science.gov (United States)

Morgan, R. P.

1975-01-01

A summary of research is presented. The broad objectives of this interdisciplinary research effort were: (1) to assess the role of satellite communications as a means of improving education in the United States, as well as in less-developed areas of the world; (2) to generate basic knowledge which will aid in making rational decisions about satellite application in the field of education in the years ahead; (3) to devise systems and strategies for improving education; and (4) to educate individuals who will be knowledgeable about aspects of satellite communications policy which transcend any single discipline.

Satellite communications for the next generation telecommunication services and networks

Science.gov (United States)

Chitre, D. M.

1991-01-01

Satellite communications can play an important role in provisioning the next-generation telecommunication services and networks, provided the protocols specifying these services and networks are satellite-compatible and the satellite subnetworks, consisting of earth stations interconnected by the processor and the switch on board the satellite, interwork effectively with the terrestrial networks. The specific parameters and procedures of frame relay and broadband integrated services digital network (B-ISDN) protocols which are impacted by a satellite delay. Congestion and resource management functions for frame relay and B-ISDN are discussed in detail, describing the division of these functions between earth stations and on board the satellite. Specific onboard and ground functions are identified as potential candidates for their implementation via neural network technology.

On the Applications of Modern Educational Technology in Maritime English Teaching from the Perspective of Constructivism

Science.gov (United States)

Cui, Zhongliang

2010-01-01

Nowadays maritime transportation has become a major modern logistics because of its large capacity and low cost. English plays a leading role in the industry of maritime transportation. It is the most important medium and an indispensable communication tool in international business and global marine industry. Maritime English teaching has made…

Air traffic management system design using satellite based geo-positioning and communications assets

Science.gov (United States)

Horkin, Phil

1995-01-01

The current FAA and ICAO FANS vision of Air Traffic Management will transition the functions of Communications, Navigation, and Surveillance to satellite based assets in the 21st century. Fundamental to widespread acceptance of this vision is a geo-positioning system that can provide worldwide access with best case differential GPS performance, but without the associated problems. A robust communications capability linking-up aircraft and towers to meet the voice and data requirements is also essential. The current GPS constellation does not provide continuous global coverage with a sufficient number of satellites to meet the precision landing requirements as set by the world community. Periodic loss of the minimum number of satellites in view creates an integrity problem, which prevents GPS from becoming the primary system for navigation. Furthermore, there is reluctance on the part of many countries to depend on assets like GPS and GLONASS which are controlled by military communities. This paper addresses these concerns and provides a system solving the key issues associated with navigation, automatic dependent surveillance, and flexible communications. It contains an independent GPS-like navigation system with 27 satellites providing global coverage with a minimum of six in view at all times. Robust communications is provided by a network of TDMA/FDMA communications payloads contained on these satellites. This network can support simultaneous communications for up to 30,000 links, nearly enough to simultaneously support three times the current global fleet of jumbo air passenger aircraft. All of the required hardware is directly traceable to existing designs.

Comparison of TCeMA and TDMA for Inter-Satellite Communications using OPNET Simulation

Science.gov (United States)

Hain, Regina Rosales; Ramanathan, Ram; Bergamo, Marcos; Wallett, Thomas M.

2003-01-01

A robust data link protocol, enabling unique physical and MAC layer technologies and sub-network level protocols, is needed in order to take advantage of the full potential of using both TDMA and CDMA in a satellite communication network. A novel MAC layer protocol, TDMA with CDMA-encoding multiple access (TCeMA) integrated with null-steered digital beam-forming spatial multiplexing, is investigated to support flexible spacecraft communications. Abstract models of the TCeMA and TDMA processes are developed in OPNFiT and a comparison of the performances of TCeMA and TDMA in a satellite network simulation are made. TCeMA provides the better connectivity and capacity with respect to TDMA for satellite communication traffic.

The C3PO project: a laser communication system concept for small satellites

Science.gov (United States)

d'Humières, Benoît; Esmiller, Bruno; Gouy, Yann; Steck, Emilie; Quintana, Crisanto; Faulkner, Graham; O'Brien, Dominic; Sproll, Fabian; Wagner, Paul; Hampf, Daniel; Riede, Wolfgang; Salter, Michael; Wang, Qin; Platt, Duncan; Jakonis, Darius; Piao, Xiaoyu; Karlsson, Mikael; Oberg, Olof; Petermann, Ingemar; Michalkiewicz, Aneta; Krezel, Jerzy; Debowska, Anna; Thueux, Yoann

2017-02-01

The satellite market is shifting towards smaller (micro and nanosatellites), lowered mass and increased performance platforms. Nanosatellites and picosatellites have been used for a number of new, innovative and unique payloads and missions. This trend requires new concepts for a reduced size, a better performance/weight ratio and a reduction of onboard power consumption. In this context, disruptive technologies, such as laser-optical communication systems, are opening new possibilities. This paper presents the C3PO1 system, "advanced Concept for laser uplink/ downlink CommuniCation with sPace Objects", and the first results of the development of its key technologies. This project targets the design of a communications system that uses a ground-based laser to illuminate a satellite, and a Modulating Retro-Reflector (MRR) to return a beam of light modulated by data to the ground. This enables a downlink, without a laser source on the satellite. This architecture suits well to small satellite applications so as high data rates are potentially provided with very low board mass. C3PO project aims to achieve data rates of 1Gbit/s between LEO satellites and Earth with a communication payload mass of less than 1kilogram. In this paper, results of the initial experiments and demonstration of the key technologies will be shown.

An up-link power control for demand assignment International Business Satellite Communications Network

Science.gov (United States)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio

Up-link power control (UPC) is one of the essential technologies to provide efficient satellite communication systems operated at frequency bands above 10 GHz. A simple and cost-effective UPC scheme applicable to a demand assignment international business satellite communications system has been developed. This paper presents the UPC scheme, including the hardware implementation and its performance.

Integration of Satellite and Terrestrial Systems in Future Multimedia Communications

OpenAIRE

Evans, Barry; Werner, Markus; Lutz, Erich; Bousquet, Michel; Corazza, Giovanni E; Maral, Gerard; Rumeau, Robert; Ferro, Erina

2005-01-01

In this article we examine the role of satellite communications in future telecommunication networks and service provision. Lessons from the past indicate that satellites are successful as a result of their wide area coverage or speed to market for new services. Niche areas such as coverage of air and sea will persist, but for land masses convergence of fixed, mobile, and broadcasting will dictate that the only way forward for satellites is in an integrated format with terrestrial systems. We...

An Analysis of Military Use of Commercial Satellite Communications

National Research Council Canada - National Science Library

Forest, Benjamin D

2008-01-01

Since the Gulf War of 1991, United States military satellite communication (SATCOM) bandwidth demand has increased dramatically, as evidenced by recent usage rates in Operation Enduring Freedom and Operation Iraqi Freedom...

NASA/DARPA advanced communications technology satellite project for evaluation of telemedicine outreach using next-generation communications satellite technology: Mayo Foundation participation.

Science.gov (United States)

Gilbert, B K; Mitchell, M P; Bengali, A R; Khandheria, B K

1999-08-01

To describe the development of telemedicine capabilities-application of remote consultation and diagnostic techniques-and to evaluate the feasibility and practicality of such clinical outreach to rural and underserved communities with limited telecommunications infrastructures. In 1992, Mayo Foundation (Rochester, Minn, Jacksonville, Fla, and Scottsdale, Ariz), the National Aeronautics and Space Administration, and the Defense Advanced Research Projects Agency collaborated to create a complex network of fiberoptic landlines, video recording systems, satellite terminals, and specially developed data translators linking Mayo sites with other locations in the continental United States on an on-demand basis. The purpose was to transmit data via the asynchronous transfer mode (ATM) digital communications protocol over the Advanced Communications Technology Satellite. The links were intended to provide a conduit for transmission of data for patient-specific consultations between physicians, evaluation of medical imagery, and medical education for clinical staffs at remote sites. Low-data-rate (LDR) experiments went live late in 1993. Mayo Clinic Rochester successfully provided medical consultation and services to 2 small regional medical facilities. High-data-rate (HDR) experiments included studies of remote digital echocardiography, store-and-forward telemedicine, cardiac catheterization, and teleconsultation for congenital heart disease. These studies combined landline data transmission with use of the satellite. The complexity of the routing paths and network components, immaturity of available software, and inexperience with existing telecommunications caused significant study delays. These experiments demonstrated that next-generation satellite technology can provide batch and real-time imagery for telemedicine. The first-generation of the ATM and satellite network technology used in these experiments created several technical problems and inconveniences that should

Rural applications of Advanced Traveler Information Systems : evaluation of satellite communications systems for mayday applications

Science.gov (United States)

This report documents the results of an evaluation of satellite communication systems for mayday applications conducted as part of the Rural Applications of Advanced Traveler Information Systems (ATIS) study. It focuses on satellite communications sy...

Estimation of the demand for public services communications. [market research and economic analysis for a communications satellite system

Science.gov (United States)

1976-01-01

Market analyses and economic studies are presented to support NASA planning for a communications satellite system to provide public services in health, education, mobile communications, data transfer, and teleconferencing.

Integration of Commercial Mobile Satellite Services into Naval Communications

National Research Council Canada - National Science Library

Stone, Cary

1997-01-01

Mobile Satellite Services (MSS) need to be integrated into Naval Communications. DoD SATCOM military owned systems fall well short of meeting DoD SATCOM requirements in general and mobile SATCOM specifically...

Application of adaptive antenna techniques to future commercial satellite communication

Science.gov (United States)

Ersoy, L.; Lee, E. A.; Matthews, E. W.

1987-01-01

The purpose of this contract was to identify the application of adaptive antenna technique in future operational commercial satellite communication systems and to quantify potential benefits. The contract consisted of two major subtasks. Task 1, Assessment of Future Commercial Satellite System Requirements, was generally referred to as the Adaptive section. Task 2 dealt with Pointing Error Compensation Study for a Multiple Scanning/Fixed Spot Beam Reflector Antenna System and was referred to as the reconfigurable system. Each of these tasks was further sub-divided into smaller subtasks. It should also be noted that the reconfigurable system is usually defined as an open-loop system while the adaptive system is a closed-loop system. The differences between the open- and closed-loop systems were defined. Both the adaptive and reconfigurable systems were explained and the potential applications of such systems were presented in the context of commercial communication satellite systems.

Servicing communication satellites in geostationary orbit

Science.gov (United States)

Russell, Paul K.; Price, Kent M.

1990-01-01

The econmic benefits of a LEO space station are quantified by identifying alternative operating scenarios utilizing the space station's transportation facilities and assembly and repair facilities. Particular consideration is given to the analysis of the impact of on-orbit assembly and servicing on a typical communications satellite is analyzed. The results of this study show that on-orbit servicing can increase the internal rate of return by as much as 30 percent.

47 CFR 80.475 - Scope of service of the Automated Maritime Telecommunications System (AMTS).

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Scope of service of the Automated Maritime Telecommunications System (AMTS). 80.475 Section 80.475 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Automated Systems § 80.475 Scope of service of the Automated Maritime Telecommunications System (AMTS). (a...

Decentralized Adaptive Overcurrent Protection for Medium Voltage Maritime Power Systems

DEFF Research Database (Denmark)

Ciontea, Catalin-Iosif; Bak, Claus Leth; Blaabjerg, Frede

2016-01-01

the entire electrical network and changes the relay settings accordingly, but this approach is not adequate for the maritime power systems. This paper propose a decentralized adaptive protection method, where each protection relay is able to identify by itself the network status without the need of a central...... control unit. The new adaptive protection method is based on communication between the overcurrent relays and the equipment that could affect the protection system, such as circuit breakers and generators. Using PSCAD, the proposed method is implemented in a test medium voltage maritime power system......More and more maritime applications as marine vessels and offshore platforms need an adaptive protection power system. However, the adaptive protection is yet to be implemented in the maritime sector. Usually, the adaptive protection implies the existence of a central control unit that monitors...

Admixture, one-source colonization or long-term persistence of maritime pine in the Castilian Plateau? Insights from nuclear micro satellite markers

Energy Technology Data Exchange (ETDEWEB)

Lucas, A. I. de; Gonzalez Martinez, S. C.; Hidalgo, E.; Bravo, F.; Heuertz, M.

2009-07-01

Atlantic and Mediterranean populations of maritime pine are very different in quantitative and adaptive traits, even to be considered different subspecies. Different authors have suggested the existence of glacial refuge for this species both in Portugal and eastern Spain based on molecular markers and supported by pollen and fossil records. In addition, based on the existence of high levels of haplotypic variation in this region, the Castilian Plateau is suggested as a contact zone between Atlantic and Mediterranean gene pools of the species. This hypothesis is tested using Bayesian clustering methods and exclusion tests based on multi locus genotypes obtained by geno typing 13 populations with three highly polymorphic nuclear micro satellites. The results show that Castilian Plateau populations constitute a different gene pool by itself that can not be fully originated from the Mediterranean or the Atlantic gene pools, or from a mixture of both. Therefore, three different hypotheses have been considered as plausible causes to give rise to Castilian Plateau maritime pine populations: i) fast colonization of the region from one or more Mediterranean refugial areas, ii) existence of cryptic refugia for the species in the zone, and iii) introduction of exotic material by humans. (Author) 55 refs.

Optimization of Power Allocation for Multiusers in Multi-Spot-Beam Satellite Communication Systems

Directory of Open Access Journals (Sweden)

Heng Wang

2014-01-01

Full Text Available In recent years, multi-spot-beam satellite communication systems have played a key role in global seamless communication. However, satellite power resources are scarce and expensive, due to the limitations of satellite platform. Therefore, this paper proposes optimizing the power allocation of each user in order to improve the power utilization efficiency. Initially the capacity allocated to each user is calculated according to the satellite link budget equations, which can be achieved in the practical satellite communication systems. The problem of power allocation is then formulated as a convex optimization, taking account of a trade-off between the maximization of the total system capacity and the fairness of power allocation amongst the users. Finally, an iterative algorithm based on the duality theory is proposed to obtain the optimal solution to the optimization. Compared with the traditional uniform resource allocation or proportional resource allocation algorithms, the proposed optimal power allocation algorithm improves the fairness of power allocation amongst the users. Moreover, the computational complexity of the proposed algorithm is linear with both the numbers of the spot beams and users. As a result, the proposed power allocation algorithm is easy to be implemented in practice.

The Advanced Communications Technology Satellite (ACTS) capabilities for serving science

Science.gov (United States)

Meyer, Thomas R.

1990-01-01

Results of research on potential science applications of the NASA Advanced Communications Technology Satellite (ACTS) are presented. Discussed here are: (1) general research on communications related issues; (2) a survey of science-related activities and programs in the local area; (3) interviews of selected scientists and associated telecommunications support personnel whose projects have communications requirements; (4) analysis of linkages between ACTS functionality and science user communications activities and modes of operation; and (5) an analysis of survey results and the projection of conclusions to a national scale.

Medical image transmission via communication satellite: evaluation of ultrasonographic images.

Science.gov (United States)

Suzuki, H; Horikoshi, H; Shiba, H; Shimamoto, S

1996-01-01

As compared with terrestrial circuits, communication satellites possess superior characteristics such as wide area coverage, broadcasting functions, high capacity, and resistance to disasters. Utilizing the narrow band channel (64 kbps) of the stationary communication satellite JCSAT1 located at an altitude of 36,000 km above the equator, we investigated satelliterelayed dynamic medical images transmitted by video signals, using hepatic ultrasonography as a model. We conclude that the "variable playing speed transmission scheme" proposed by us is effective for the transmission of dynamic images in the narrow band channel. This promises to permit diverse utilization and applications for purposes such as the transmission of other types of ultrasonic images as well as remotely directed medical diagnosis and treatment.

Causal relationships between solar proton events and single event upsets for communication satellites

Science.gov (United States)

Lohmeyer, W. Q.; Cahoy, K.; Liu, Shiyang

In this work, we analyze a historical archive of single event upsets (SEUs) maintained by Inmarsat, one of the world's leading providers of global mobile satellite communications services. Inmarsat has operated its geostationary communication satellites and collected extensive satellite anomaly and telemetry data since 1990. Over the course of the past twenty years, the satellites have experienced more than 226 single event upsets (SEUs), a catch-all term for anomalies that occur in a satellite's electronics such as bit-flips, trips in power supplies, and memory changes in attitude control systems. While SEUs are seemingly random and difficult to predict, we correlate their occurrences to space weather phenomena, and specifically show correlations between SEUs and solar proton events (SPEs). SPEs are highly energetic protons that originate from solar coronal mass ejections (CMEs). It is thought that when these particles impact geostationary (GEO) satellites they can cause SEUs as well as solar array degradation. We calculate the associated statistical correlations that each SEU occurs within one day, one week, two weeks, and one month of 10 MeV SPEs between 10 - 10,000 particle flux units (pfu). However, we find that SPEs are most prevalent at solar maximum and that the SEUs on Inmarsat's satellites occur out of phase with the solar maximum. Ultimately, this suggests that SPEs are not the primary cause of the Inmarsat SEUs. A better understanding of the causal relationship between SPEs and SEUs will help the satellite communications industry develop component and operational space weather mitigation techniques as well as help the space weather community to refine radiation models.

Broadband and scalable mobile satellite communication system for future access networks

Science.gov (United States)

Ohata, Kohei; Kobayashi, Kiyoshi; Nakahira, Katsuya; Ueba, Masazumi

2005-07-01

Due to the recent market trends, NTT has begun research into next generation satellite communication systems, such as broadband and scalable mobile communication systems. One service application objective is to provide broadband Internet access for transportation systems, temporal broadband access networks and telemetries to remote areas. While these are niche markets the total amount of capacity should be significant. We set a 1-Gb/s total transmission capacity as our goal. Our key concern is the system cost, which means that the system should be unified system with diversified services and not tailored for each application. As satellites account for a large portion of the total system cost, we set the target satellite size as a small, one-ton class dry mass with a 2-kW class payload power. In addition to the payload power and weight, the mobile satellite's frequency band is extremely limited. Therefore, we need to develop innovative technologies that will reduce the weight and maximize spectrum and power efficiency. Another challenge is the need for the system to handle up to 50 dB and a wide data rate range of other applications. This paper describes the key communication system technologies; the frequency reuse strategy, multiplexing scheme, resource allocation scheme, and QoS management algorithm to ensure excellent spectrum efficiency and support a variety of services and quality requirements in the mobile environment.

Hybrid Maritime Warfare

DEFF Research Database (Denmark)

Schaub Jr, Gary John; Murphy, Martin; Hoffman, Frank

2017-01-01

Russia’s use of hybrid warfare techniques has raised concerns about the security of the Baltic States. Gary Schaub, Jr, Martin Murphy and Frank G Hoffman recommend a series of measures to augment NATO’s Readiness Action Plan in the Baltic region, including increasing the breadth and depth of naval...... exercises, and improving maritime domain awareness through cooperative programmes. They also suggest unilateral and cooperative measures to develop a sound strategic communications strategy to counter Moscow’s information operations, reduce dependence on Russian energy supplies and build the resilience...

Texas Telecommunication Satellite Demonstration Project. Planning Effort for Application of Communication Satellites in Education.

Science.gov (United States)

Education Service Center Region 4, Houston, TX.

The primary goal of the Texas Telecommunication Satellite Demonstration consortium is to install, operate, and evaluate a comprehensive communication service delivery system which would provide the citizens of Texas with greater opportunity for equal access to education and information. The four major objectives of the demonstration are (1) to…

Military Dependence on Commercial Satellite Communications Systems - Strength or Vulnerability

National Research Council Canada - National Science Library

Hook, Jack

1999-01-01

The military's growing dependence on commercial satellite communications systems will become a strength or vulnerability based on how well the right balance is achieved between commercial and military systems...

Optimization of communication network topology for navigation sharing among distributed satellites

Science.gov (United States)

Dang, Zhaohui; Zhang, Yulin

2013-01-01

Navigation sharing among distributed satellites is quite important for coordinated motion and collision avoidance. This paper proposes optimization methods of the communication network topology to achieve navigation sharing. The whole communication network constructing by inter-satellite links are considered as a topology graph. The aim of this paper is to find the communication network topology with minimum communication connections' number (MCCN) in different conditions. It has found that the communication capacity and the number of channels are two key parameters affecting the results. The model of MCCN topology for navigation sharing is established and corresponding method is designed. Two main scenarios, viz., homogeneous case and heterogeneous case, are considered. For the homogeneous case where each member has the same communication capacity, it designs a construction method (Algorithm 1) to find the MCCN topology. For the heterogeneous case, it introduces a modified genetic algorithm (Algorithm 2) to find the MCCN topology. When considering the fact that the number of channels is limited, the Algorithm 2 is further modified by adding a penalized term in the fitness function. The effectiveness of these algorithms is all proved in theoretical. Three examples are further tested to illustrate the methods developed in this paper.

Integration of an ion engine on the Communications Technology Satellite.

Science.gov (United States)

Payne, W. F.; Finke, R. C.

1972-01-01

An ion engine subsystem intended for satellite stationkeeping tasks is described. Ion thrusters are chosen to perform the task because the specific impulse is at least an order of magnitude higher than the commonly used reaction control jets. The higher the value of specific impulse, the greater the total impulse that can be attained for a given weight of propellant, hence cost benefits result. The integration, subsystem testing, and the operating plans for the ion engine experiment to be flown in 1975 on the Canadian Communications Technology Satellite (CTS) are described. The subsystem is designed to demonstrate north-south stationkeeping, attitude control by means of thrust vectoring, long-term space storage and restart capability, and compatibility with a high powered communications transponder.

Australia's Domestic Communication Satellite and Education: Has Education Missed the Boat?

Science.gov (United States)

White, Peter B.

Educators have been critized for being unable to develop any firm plans for the use of Australia's Domestic Communications Satellite (AUSSAT). However, conferences, talks, and papers have resulted in some significant achievements. First, it is now possible to raise issues of communications and telecommunications planning at the very highest…

A network architecture for International Business Satellite communications

Science.gov (United States)

Takahata, Fumio; Nohara, Mitsuo; Takeuchi, Yoshio

Demand Assignment (DA) control is expected to be introduced in the International Business Satellte communications (IBS) network in order to cope with a growing international business traffic. The paper discusses the DA/IBS network from the viewpoints of network configuration, satellite channel configuration and DA control. The network configuration proposed here consists of one Central Station with network management function and several Network Coordination Stations with user management function. A satellite channel configuration is also presented along with a tradeoff study on transmission bit rate, high power amplifier output power requirement, and service quality. The DA control flow and protocol based on CCITT Signalling System No. 7 are also proposed.

ACTS TDMA network control. [Advanced Communication Technology Satellite

Science.gov (United States)

Inukai, T.; Campanella, S. J.

1984-01-01

This paper presents basic network control concepts for the Advanced Communications Technology Satellite (ACTS) System. Two experimental systems, called the low-burst-rate and high-burst-rate systems, along with ACTS ground system features, are described. The network control issues addressed include frame structures, acquisition and synchronization procedures, coordinated station burst-time plan and satellite-time plan changes, on-board clock control based on ground drift measurements, rain fade control by means of adaptive forward-error-correction (FEC) coding and transmit power augmentation, and reassignment of channel capacities on demand. The NASA ground system, which includes a primary station, diversity station, and master control station, is also described.

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

Science.gov (United States)

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

1981-01-01

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.

77 FR 51045 - Certain Two-Way Global Satellite Communication Devices, System and Components Thereof; Notice of...

Science.gov (United States)

2012-08-23

... Certain Two-Way Global Satellite Communication Devices, System and Components Thereof, DN 2907; the... INTERNATIONAL TRADE COMMISSION [Docket No. 2907] Certain Two-Way Global Satellite Communication Devices, System and Components Thereof; Notice of Receipt of Complaint; Solicitation of Comments Relating...

The 30/20 GHz communications satellite trunking network study

Science.gov (United States)

Kolb, W.

1981-01-01

Alternative transmission media for a CONUS-wide trunking network in the years 1990 and 2000 are examined. The alternative technologies comprised fiber optic cable, conventional C- and Ku-band satellites, and 30/20 GHz satellites. Three levels of implementation were considered - a 10-city network, a 20-city network, and a 40-city network. The cities selected were the major metropolitan areas with the greatest communications demand. All intercity voice, data, and video traffic carried more than 40 miles was included in the analysis. In the optimized network, traffic transmitted less than 500 miles was found to be better served by fiber optic cable in 1990. By the year 2000, the crossover point would be down to 200 miles, assuming availability of 30/20 GHz satellites.

Utilization of photovoltaic for broadband satellite communications in rural area of Thailand

Science.gov (United States)

Jinayim, Theerawut; Mungkung, Narong; Kasayapanand, Nat

2013-06-01

Electricity, Information and Communication Technologies (ICTs) are very important not only in urban areas but also in rural areas. To provide ICTs service in rural areas, sources of electricity and communication infrastructures must be implemented. Electricity is a major condition due to the fact that all electronic devices needed it in order to power on, so that it is impossible to operate any forms of ICTs in areas where the main national grid line is unavailable. Almost rural areas of Thailand where the main national grid line is unavailable have very good sunlight intensity. Photovoltaic is the most effective renewable energy technologies in those areas for meeting electricity needed in areas that are not connected to the main national grid line. In this paper, the efficiency utilization of photovoltaic as source of electricity for broadband satellite communication systems as well as social and economic impact and quality of life of people in rural areas of Thailand are presented. The results show that most rural communities would be able to universally access to the basic telecommunications services such as internet access and public telephone via satellite communication systems. However, in some field case study, broadband internet access via satellite communication may be unnecessary for some rural communities and the most exactly rural communities needed are electricity for household usage and battery charger.

33 CFR 101.300 - Preparedness communications.

Science.gov (United States)

2010-07-01

... MARITIME SECURITY MARITIME SECURITY: GENERAL Communication (Port-Facility-Vessel) § 101.300 Preparedness... transportation security incident, the COTP will, when appropriate, communicate to the port stakeholders, vessels... risk. (c) Attainment. (1) Each owner or operator of a vessel or facility required to have a security...

The Future of Satellite Communications. Resource Management and the Needs of Nations.

Science.gov (United States)

Hinchman, Walter R.; Dunn, D. A.

Recent events suggest that Intelsat (the 68-nation International Telecommunications Satellite Consortium) will coordinate a number of domestic and regional systems that provide satellite communications services, some of which will be maintained by Intelsat and some of which will be independent. This report addresses the problems of conflict in…

Apple - Indian experimental geostationary communication satellite

Science.gov (United States)

Rao, U. R.; Vasagam, R. M.

Developmental steps, responsibilities, design goals, performance characteristics, and support systems for the ISRO Ariane Passenger Payload Experiment (APPLE) experimental GEO communication satellite are described. The spacecraft underwent structural, thermal, engineering, prototype, and flight qualification tests in India before being shipped to Guyana for launch on the third Ariane test flight. APPLE carries a redundant C-band communication transponder fed by a 900 mm diam parabolic reflector. A 6 GHz uplink and 4 GHz downlink are processed through a diplexer, with the receiver employing a low noise GaAs FET amplifier. In-orbit telemetry is provided by a 4095 MHz beacon with a data rate of 64 bits/sec. Two solar panels supply 210 W of power, while an on-board Ni-Cd storage battery stores 240 Wh for the ascent and during eclipse. Teleconferencing has been successfully performed using the spacecraft link.

Developing a Model on Improving Maritime English Training for Maritime Transportation Safety

Science.gov (United States)

Yercan, Funda; Fricke, Donna; Stone, Laurie

2005-01-01

Maritime services form an integral part of what regulatory agencies requires for the safe navigation and operation of vessels. Therefore, the maritime industry's compliance with governmental regulations and international protocols has been essential for maritime safety management. As a basis to this aspect, the preparation of maritime students as…

A Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

OpenAIRE

Jong Won Eun

2000-01-01

It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifet...

Study of LEO-SAT microwave link for broad-band mobile satellite communication system

Science.gov (United States)

Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

1993-01-01

In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

DOD Use of Commercial Wideband Satellite Communications Systems: How Much is Needed, and How Do We Get It?

National Research Council Canada - National Science Library

Hutchens, Robert

2001-01-01

..., A key enabler to this end is sufficient wideband satellite communications connectivity DoD's organic wideband satellite communications capabilities are inadequate, so commercial services must be used...

Green Maritime Logistics

DEFF Research Database (Denmark)

Psaraftis, Harilaos N.

2016-01-01

By green maritime logistics we mean achieving an acceptable environmental performance of the maritime transport logistical supply chain while at the same time respecting traditional economic criteria. In this paper the environmental focus is on maritime emissions. Achieving such goal may involve ...

Intersatellite Link (ISL) application to commercial communications satellites. Volume 1: Executive summary

Science.gov (United States)

Young, S. Lee

1987-01-01

Based on a comprehensive evaluation of the fundamental Intersatellite Link (ISL) systems characteristics, potential applications of ISLs to domestic, regional, and global commercial satellite communications were identified, and their cost-effectiveness and other systems benefits quantified wherever possible. Implementation scenarios for the cost-effective communications satellite systems employing ISLs were developed for the first launch in 1993 to 1994 and widespread use of ISLs in the early 2000's. Critical technology requirements for both the microwave (60 GHz) and optical (0.85 micron) ISL implementations were identified, and their technology development programs, including schedule and cost estimates, were derived.

Image segmentation-based oil slick detection using SAR Radarsat-2 OSVN maritime data

CSIR Research Space (South Africa)

Mdakane, Lizwe W

2017-07-01

Full Text Available (RS2) Maritime Satellite Surveillance Radar (MSSR) modes have been developed to further improve ocean surveillance. This data can monitor large areas (400 km for SEN1 EW and over 500 km for RS2 OSVN), with a finer resolution. These modes enable...

Networks systems and operations. [wideband communication techniques for data links with satellites

Science.gov (United States)

1975-01-01

The application of wideband communication techniques for data links with satellites is discussed. A diagram of the demand assigned voice communications system is provided. The development of prototype integrated spacecraft paramps at S- and C-bands is described and the performance of space-qualified paramps is tabulated. The characteristics of a dual parabolic cylinder monopulse zoom antenna for use with the tracking and data relay satellite system (TDRSS) are analyzed. The development of a universally applicable transponder at S-band is reported. A block diagram of the major subassemblies of the S-band transponder is included. The technology aspects of network timing and synchronization of communication systems are to show the use of the Omega navigation system. The telemetry data compression system used during the Skylab program is evaluated.

Intersatellite link application to commercial communications satellites

Science.gov (United States)

Lee, Young S.; Atia, Ali E.; Ponchak, Denise S.

1988-01-01

The fundamental characteristics of intersatellite link (ISL) systems, and their application to domestic, regional, and global satellite communications, are described. The quantitative advantages of using ISLs to improve orbit utilization, spectrum occupancy, transmission delay (compared to multi-hop links), coverage, and connectivity, and to reduce the number of earth station antennas, are also presented. Cost-effectiveness and other systems benefits of using ISLs are identified, and the technical and systems planning aspects of ISL systems implementation are addressed.

The Maritime Infrastructure Recovery Plan for the National Strategy for Maritime Security

National Research Council Canada - National Science Library

2006-01-01

... to the jurisdiction of the United States. The MIRP, the Maritime Commerce Security Plan, and the Maritime Transportation System Security Plan were developed in close coordination under the National Strategy for Maritime Security (NSMS...

An assessment of the status and trends in satellite communications 1986-2000: An information document prepared for the Communications Subcommittee of the Space Applications Advisory Committee

Science.gov (United States)

Poley, W. A.; Stevens, G. H.; Stevenson, S. M.; Lekan, J.; Arth, C. H.; Hollansworth, J. E.; Miller, E. F.

1986-01-01

This is a response to a Space Applications Advisory Committee (SAAC) request for information about the status and trends in satellite communications, to be used to support efforts to conceive and recommend long range goals for NASA communications activities. Included in this document are assessments of: (1) the outlook for satellite communications, including current applications, potential future applications, and impact of the changing environment such as optical fiber networks, the Integrated Services Digital Network (ISDN) standard, and the rapidly growing market for Very Small Aperture Terminals (VSAT); (2) the restrictions imposed by our limited spectrum resource; and (3) technology needs indicated by future trends. Potential future systems discussed include: large powerful satellites for providing personal communications; VSAT compatible satellites with onboard switching and having voice capability; large satellites which offer a pervasive T1 network service (primarily for video-phone); and large geostationary communications facilities which support common use by several carriers. Also, discussion is included of NASA particular needs and possible future systems. Based on the mentioned system concepts, specific technology recommendations are provided for the time frames of now - 1993, 1994 - 2000, and 2000 - 2010.

Maritime security report. November 2000 [Commercial maritime drug smuggling

Science.gov (United States)

2000-11-01

Port and security programs being implemented in Colombia's port facilities, maritime jurisdictions, and the marine intermodal shipping cycle are producing successful results against commercial maritime drug smuggling. This security reports examines t...

Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM

Science.gov (United States)

Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

1999-01-01

The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

Taking the Politics Out of Satellite and Space-Based Communications Protocols

Science.gov (United States)

Ivancic, William D.

2006-01-01

After many years of studies, experimentation, and deployment, large amounts of misinformation and misconceptions remain regarding applicability of various communications protocols for use in satellite and space-based networks. This paper attempts to remove much of the politics, misconceptions, and misinformation that have plagued spacebased communications protocol development and deployment. This paper provides a common vocabulary for communications; a general discussion of the requirements for various communication environments; an evaluation of tradeoffs between circuit and packet-switching technologies, and the pros and cons of various link, network, transport, application, and security protocols. Included is the applicability of protocol enhancing proxies to NASA, Department of Defense (DOD), and commercial space communication systems.

Technology programs and related policies - Impacts on communications satellite business ventures

Science.gov (United States)

Greenberg, J. S.

1985-01-01

The DOMSAT II stochastic communication satellite business venture financial planning simulation model is described. The specification of business scenarios and the results of several analyses are presented. In particular, the impacts of NASA on-orbit propulsion and power technology programs are described. The effects of insurance rates and self-insurance and of the use of the Space Shuttle and Ariane transportation systems on a typical fixed satellite service business venture are discussed.

An approach to effective UHF (S/L band) data communications for satellite Personal Communication Service (PCS)

Science.gov (United States)

Hayase, Joshua Y.

1995-01-01

Reliable signaling information transfer is fundamental in supporting the needs of data communication PCS via LMS (Land Mobile Service) SSs (satellite systems). The needs of the system designer can be satisfied only through the collection of media information that can be brought to bear on the pertinent design issues. We at ISI hope to continue our dialogue with fading media experts to address the unique data communications needs of PCS via LMS SSs.

Maritime Technology

DEFF Research Database (Denmark)

Sørensen, Herman

1997-01-01

Elementary introduction to the subject "Maritime Technology".The contents include drawings, sketches and references in English without any supplementary text.......Elementary introduction to the subject "Maritime Technology".The contents include drawings, sketches and references in English without any supplementary text....

Trellis-coded CPM for satellite-based mobile communications

Science.gov (United States)

Abrishamkar, Farrokh; Biglieri, Ezio

1988-01-01

Digital transmission for satellite-based land mobile communications is discussed. To satisfy the power and bandwidth limitations imposed on such systems, a combination of trellis coding and continuous-phase modulated signals are considered. Some schemes based on this idea are presented, and their performance is analyzed by computer simulation. The results obtained show that a scheme based on directional detection and Viterbi decoding appears promising for practical applications.

Satellite communication system for emergency monitoring within the Chernobyl exclusion zone

International Nuclear Information System (INIS)

Franchini, C.; Mensa, M.; Kanevsky, V.A.

1997-01-01

A Satellite Emergency Monitoring system of the Chernobyl Exclusive Zone (SEM CEZ) was designed to provide the Ukraine authorities and the neighbouring countries with updated information when an emergency situation occurs in the Exclusion Zone. This is of particular importance when environment contamination has transboundary effect. SEM system consists of mobile and fixed sensors reporting data via a dedicated satellite communications link. Mobile sensors are fitted with Global Positioning System (GPS) receivers that determine current coordinates of the sensor. Sensors data are transmitted to the Emergency Monitoring Centre equipped with PC and a satellite terminal. Both sensors data and the current position are visualized on digital maps

Intuitive Tools for the Design and Analysis of Communication Payloads for Satellites

Science.gov (United States)

Culver, Michael R.; Soong, Christine; Warner, Joseph D.

2014-01-01

In an effort to make future communications satellite payload design more efficient and accessible, two tools were created with intuitive graphical user interfaces (GUIs). The first tool allows payload designers to graphically design their payload by using simple drag and drop of payload components onto a design area within the program. Information about each picked component is pulled from a database of common space-qualified communication components sold by commerical companies. Once a design is completed, various reports can be generated, such as the Master Equipment List. The second tool is a link budget calculator designed specifically for ease of use. Other features of this tool include being able to access a database of NASA ground based apertures for near Earth and Deep Space communication, the Tracking and Data Relay Satellite System (TDRSS) base apertures, and information about the solar system relevant to link budget calculations. The link budget tool allows for over 50 different combinations of user inputs, eliminating the need for multiple spreadsheets and the user errors associated with using them. Both of the aforementioned tools increase the productivity of space communication systems designers, and have the colloquial latitude to allow non-communication experts to design preliminary communication payloads.

R and D limited partnerships (possible applications in advanced communications satellite technology experiment program)

Science.gov (United States)

1985-01-01

Typical R&D limited partnership arrangements, advantages and disadvantages of R&D limited partnership (RDLPs) and antitrust and tax implications are described. A number of typical forms of RDLPs are described that may be applicable for use in stimulating R&D and experimental programs using the advanced communications technology satellite. The ultimate goal is to increase the rate of market penetration of goods and/or services based upon advanced satellite communications technology. The conditions necessary for these RDLP forms to be advantageous are outlined.

Communications systems for emergency deployment applications

International Nuclear Information System (INIS)

Gladden, C.A.

1987-01-01

The Emergency Response Team (ERT) communications system was developed by the US Department of Energy (DOE) to provide radio and telecommunications service for scientific and management elements located in, and adjacent to, an emergency area. The telephone system consists of six nodes, interconnected via microwave links that support T-1 data links and simultaneous two-way live video. The radio network is a self-contained VHF system arranged around portable and programmable repeaters. The system is comprised of approximately 183 DES voice-private radios and 168 clear text radios. Capability is available in the form of portable International Maritime Satellite (INMARSAT) terminals that allow direct dial access to coast earth stations in the US or other countries

Proportional fair scheduling algorithm based on traffic in satellite communication system

Science.gov (United States)

Pan, Cheng-Sheng; Sui, Shi-Long; Liu, Chun-ling; Shi, Yu-Xin

2018-02-01

In the satellite communication network system, in order to solve the problem of low system capacity and user fairness in multi-user access to satellite communication network in the downlink, combined with the characteristics of user data service, an algorithm study on throughput capacity and user fairness scheduling is proposed - Proportional Fairness Algorithm Based on Traffic(B-PF). The algorithm is improved on the basis of the proportional fairness algorithm in the wireless communication system, taking into account the user channel condition and caching traffic information. The user outgoing traffic is considered as the adjustment factor of the scheduling priority and presents the concept of traffic satisfaction. Firstly,the algorithm calculates the priority of the user according to the scheduling algorithm and dispatches the users with the highest priority. Secondly, when a scheduled user is the business satisfied user, the system dispatches the next priority user. The simulation results show that compared with the PF algorithm, B-PF can improve the system throughput, the business satisfaction and fairness.

A Norwegian study of seafarers' and rescuers' recommendations for maritime telemedicine services.

Science.gov (United States)

Norum, Jan; Moksness, Stein Gunnar; Larsen, Eli

2002-01-01

We studied maritime telemedicine and its potential for improvement. Twenty-four people representing 13 different shipping companies and maritime public authorities were interviewed. They covered all areas of the Norwegian maritime sector except for offshore installations. The morbidity pattern reported differed between the groups: on cruise liners and ferries the major problems were due to coronary heart disease, while on merchant ships, navy vessels and in the fishing fleet the major problems were accidents. Voice and fax systems were available in all cases. However, the Emergency Medical Dispatch Centres did not offer an email service and did not use faxes in the maritime setting. Radio Medico Norway was the only assistance provider offering two-way transfer of digital pictures. The interviewees suggested a number of areas for improvement; these included having a single emergency telephone number to call for help, email systems with the possibility of digital picture attachments, wireless communication systems on board and a standard CD-ROM reference work for medical guidance/education.

Research of remote control for Chinese Antarctica Telescope based on iridium satellite communication

Science.gov (United States)

Xu, Lingzhe; Yang, Shihai

2010-07-01

Astronomers are ever dreaming of sites with best seeing on the Earth surface for celestial observation, and the Antarctica is one of a few such sites only left owing to the global air pollution. However, Antarctica region is largely unaccessible for human being due to lacking of fundamental living conditions, travel facilities and effective ways of communication. Worst of all, the popular internet source as a general way of communication scarcely exists there. Facing such a dilemma and as a solution remote control and data transmission for telescopes through iridium satellite communication has been put forward for the Chinese network Antarctic Schmidt Telescopes 3 (AST3), which is currently under all round research and development. This paper presents iridium satellite-based remote control application adapted to telescope control. The pioneer work in China involves hardware and software configuration utilizing techniques for reliable and secure communication, which is outlined in the paper too.

47 CFR 80.1109 - Distress, urgency, and safety communications.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Distress, urgency, and safety communications. 80.1109 Section 80.1109 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS...

Maritime oil freight flows to 2050: Delphi perceptions of maritime specialists

International Nuclear Information System (INIS)

Dinwoodie, John; Tuck, Sarah; Rigot-Müller, Patrick

2013-01-01

This paper aims to synthesise maritime specialists' perceptions of changing patterns of maritime oil freight flows to 2050. Debate spans published maritime oil flows globally, diverse drivers of future flows including economic growth, shipping market changes and haul lengths. A classic Delphi study to explore the perceptions of likely trends and flows to 2050 recruited a panel of early career and established maritime specialists, many with long term career commitments to this industry. Underpinned by market volatility and legislative uncertainty, the perceptions of both groups coincided and were conservative. Local sourcing, new Arctic seaways and fossil fuel intolerance will tend to reduce oil freight work but perceptions of ship re-routing to avoid for example Emission Control Areas and piracy would tend to lengthen hauls. In advanced industrial nations, reducing energy intensities and diminishing social tolerance of fossil fuels imply gradually reducing maritime oil shipments. However, to achieve radical national commitments to carbon emissions reductions will necessitate specialist education for naturally conservative maritime professionals and vigorous oil import reduction policies to curtail domestic demand for oil shipments. - Highlights: • Local sourcing, Arctic seaways and fossil fuel intolerance lessen oil freight work. • Oil hauls lengthen if ships re-route to avoid Emission Control Areas and piracy. • Conservative perceptions of established specialists match early career views. • Carbon emission reduction policies imply significantly reduced oil shipments. • Attitude change in maritime professionals will require education and marketing

Satellite Communications Industry

Science.gov (United States)

1993-04-01

Ariane $loom SAJAC 1 Hughes Satellite Japan 06/94 $150m SAJAC 2 Hughes Satellite Japan -- (spare) $150m SatcomHl GE GE Americom /95 $50m SOLIDARIDAD ...1 Hughes SCT (Mexico) 11/93 Ariane $loom SOLIDARIDAD 2 Hughes SCT (Mexico) /94 $loom Superbird Al Loral Space Com Gp (Jap) 11/92 Ariane $175m

Mechanical Design of Military Communication Satellite X-band PCM

Directory of Open Access Journals (Sweden)

Hyung Je Woo

1998-12-01

Full Text Available Before an actual military communications satellite is designed and constructed, a feasibility study should take place. The basic functions of such system can be observed and demonstrated in an X-Band payload simulator. For this purpose a Payload Concept Model (PCM for X-Band payload subsystem has been developed to simulate the workings of an actual military communications payload. This paper explains and illustrates the mechanical design, manufacture, and integration of the PCM. Basic RF tests also have been performed in order to verify the design requirement of the system. The results demonstrate successful development of the PCM and operation without RF losses.

Emerging markets for satellite data communications in the public service

Science.gov (United States)

Potter, J. G.

1978-01-01

The paper discusses some of the current and potential markets for satellite data communications as projected by the Public Service Satellite Consortium (PSSC). Organizations in the public service sector are divided into three categories, depending on their expected benefits and organizational changes due to increased satellite telecommunications use: A - modest institutional adjustments are necessary and significant productivity gains are likely; B - institutional requirements picture is promising, but more information is needed to assess benefits and risk; and C - major institutional adjustments are needed, risks are high but possible benefits are high. These criteria are applied to the U.S. health care system, continuing education, equipment maintenance, libraries, environmental monitoring, and other potential markets. The potential revenues are seen to be significant, but what is needed is a cooperative effort by common carriers and major public service institutions to aggregate the market.

On Importance of the Hypertext Use in Maritime English Teaching

Directory of Open Access Journals (Sweden)

Z. Bezhanovi

2015-09-01

Full Text Available The aim of the given paper is to present a set of the advantages and benefits expected by the application of the hypertext technologies in Maritime English teaching. Specification of minimum standard of competence for the officers on board the ships of 500 gross tonnage or more requires “adequate knowledge of English to enable the officer to use charts and other nautical publications, to understand meteorological information and messages concerning ship’s safety and operation, to communicate with other ships, coast stations and Vessel Traffic Service centres and to perform the officer’s duties with a multilingual crew, including the ability to use and understand the Standard Marine Communication Phrases” IMO Publishing (2011. Thus, a wide range of the results to be achieved during the process of Maritime Education and Training implementation related to the language competence development needs application of modern approaches actively used in different fields of skills - oriented education.

47 CFR 25.101 - Basis and scope.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Basis and scope. 25.101 Section 25.101 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS... 501(c)(6) of the International Maritime Satellite Telecommunications Act, and titles I through III of...

Optimizing communication satellites payload configuration with exact approaches

Science.gov (United States)

Stathakis, Apostolos; Danoy, Grégoire; Bouvry, Pascal; Talbi, El-Ghazali; Morelli, Gianluigi

2015-12-01

The satellite communications market is competitive and rapidly evolving. The payload, which is in charge of applying frequency conversion and amplification to the signals received from Earth before their retransmission, is made of various components. These include reconfigurable switches that permit the re-routing of signals based on market demand or because of some hardware failure. In order to meet modern requirements, the size and the complexity of current communication payloads are increasing significantly. Consequently, the optimal payload configuration, which was previously done manually by the engineers with the use of computerized schematics, is now becoming a difficult and time consuming task. Efficient optimization techniques are therefore required to find the optimal set(s) of switch positions to optimize some operational objective(s). In order to tackle this challenging problem for the satellite industry, this work proposes two Integer Linear Programming (ILP) models. The first one is single-objective and focuses on the minimization of the length of the longest channel path, while the second one is bi-objective and additionally aims at minimizing the number of switch changes in the payload switch matrix. Experiments are conducted on a large set of instances of realistic payload sizes using the CPLEX® solver and two well-known exact multi-objective algorithms. Numerical results demonstrate the efficiency and limitations of the ILP approach on this real-world problem.

A communication protocol for mobile satellite systems affected by rain attenuation

Science.gov (United States)

Lay, Norman; Dessouky, Khaled

1992-01-01

A communication protocol is described that has been developed as part of a K/Ka-band mobile terminal breadboard system to be demonstrated through NASA's Advanced Communications Technology Satellite (ACTS) in 1993. The protocol is aimed at providing the means for enhancing link availability and continuity by supporting real-time data rate selection and changes during rain events. Particular attention is given to the system architecture; types of links, connections, and packets; the protocol procedures; and design rationales.

A new antenna concept for satellite communications

Science.gov (United States)

Skahill, G.; Ciccolella, D.

1982-01-01

A novel antenna configuration of two reflecting surfaces and a phased array is examined for application to satellite communications and shown to be superior in every respect to earlier designs for service to the continental United States from synchronous orbit. The vignetting that afflicts other two reflector optical systems is eliminated by use of a reflecting field element. The remaining aberrations, predominantly coma, are isolated in the time delay distribution at the surface of the array and can be compensated by ordinary array techniques. The optics exhibits infinite bandwidth and the frequency range is limited only by the design of the array.

47 CFR 3.24 - Evidence of financial responsibility.

Science.gov (United States)

2010-10-01

... Section 3.24 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL AUTHORIZATION AND ADMINISTRATION OF ACCOUNTING AUTHORITIES IN MARITIME AND MARITIME MOBILE-SATELLITE RADIO SERVICES Application... financial status. To the extent that the applicant is a business, formal financial statements will be...

Satellite-based quantum communication terminal employing state-of-the-art technology

Science.gov (United States)

Pfennigbauer, Martin; Aspelmeyer, Markus; Leeb, Walter R.; Baister, Guy; Dreischer, Thomas; Jennewein, Thomas; Neckamm, Gregor; Perdigues, Josep M.; Weinfurter, Harald; Zeilinger, Anton

2005-09-01

Feature Issue on Optical Wireless Communications (OWC) We investigate the design and the accommodation of a quantum communication transceiver in an existing classical optical communication terminal on board a satellite. Operation from a low earth orbit (LEO) platform (e.g., the International Space Station) would allow transmission of single photons and pairs of entangled photons to ground stations and hence permit quantum communication applications such as quantum cryptography on a global scale. Integration of a source generating entangled photon pairs and single-photon detection into existing optical terminal designs is feasible. Even more, major subunits of the classical terminals such as those for pointing, acquisition, and tracking as well as those providing the required electronic, thermal, and structural backbone can be adapted so as to meet the quantum communication terminal needs.

Space transportation. [user needs met by information derived from satellites and the interface with space transportation systems

Science.gov (United States)

1975-01-01

User-oriented panels were formed to examine practical applications of information or services derived from earth orbiting satellites. Topics discussed include: weather and climate; uses of communication; land use planning; agriculture, forest, and range; inland water resources; retractable resources; environmental quality; marine and maritime uses; and materials processing in space. Emphasis was placed on the interface of the space transportation system (STS) with the applications envisioned by the user panels. User requirements were compared with expected STS capabilities in terms of availability, carrying payload to orbit, and estimated costs per launch. Conclusions and recommendations were reported.

Design of an anti-Rician-fading modem for mobile satellite communication systems

Science.gov (United States)

Kojima, Toshiharu; Ishizu, Fumio; Miyake, Makoto; Murakami, Keishi; Fujino, Tadashi

1995-01-01

To design a demodulator applicable to mobile satellite communication systems using differential phase shift keying modulation, we have developed key technologies including an anti-Rician-fading demodulation scheme, an initial acquisition scheme, automatic gain control (AGC), automatic frequency control (AFC), and bit timing recovery (BTR). Using these technologies, we have developed one-chip digital signal processor (DSP) modem for mobile terminal, which is compact, of light weight, and of low power consumption. Results of performance test show that the developed DSP modem achieves good performance in terms of bit error ratio in mobile satellite communication environment, i.e., Rician fading channel. It is also shown that the initial acquisition scheme acquires received signal rapidly even if the carrier-to-noise power ratio (CNR) of the received signal is considerably low.

Personal communications via ACTS satellite HBR transponders

Science.gov (United States)

Fang, Russell J. F.

1991-01-01

The concept of a fully meshed network of briefcase-sized terminals is presented for personal communications over Ka-band satellite transponders. In this concept, undesirable double-hop delays are avoided for voice communications. The bandwidth and power resources of the transponder are efficiently shared by users in a simple demand-assigned manner via code-division multiple access (CDMA). Voice, data, and facsimile are statistically multiplexed at each terminal. In order to minimize terminal costs, frequency-precorrected, and level-preadjusted continuous-wave tones are sent from the central network control station in each beam so that the terminals in each down-link beam can use these pilots as references for antenna acquisition and tracking, as reliable frequency sources, and as indicators of signal fade for up-link power control (ULPC). The potential CDMA 'near-far' problem due to up-link fades is mitigated by using ULPC. Quasi-burst mode transmission is employed to minimize the potential clock and pseudorandom number code synchronization.

Maritime environmental penal law. International and German legislation; Maritimes Umweltstrafrecht. Voelkerrechtliche Grundlagen und deutsches Recht

Energy Technology Data Exchange (ETDEWEB)

Eller, Jan Frederik

2017-07-01

The book on maritime environmental penal law discusses the following issues: part I: introduction into the importance of oceanic environment and its thread, requirement of protective measures,; part II: focus of the study and terminology: oceanic pollution, maritime environmental legislation, international legislation; part 3: international legislative regulations concerning the protection of maritime environment: avoidance of environmental pollution, maritime legislative agreements, existing protective institutions; part 4: state penal power concerning maritime environmental protection; part 5: statutory offense according to German legislation; perspectives for regulations concerning criminal acts on sea.

Evaluation of spacecraft technology programs (effects on communication satellite business ventures), volume 2

Science.gov (United States)

Greenburg, J. S.; Kaplan, M.; Fishman, J.; Hopkins, C.

1985-01-01

The computational procedures used in the evaluation of spacecraft technology programs that impact upon commercial communication satellite operations are discussed. Computer programs and data bases are described.

NASA satellite communications application research. Phase 2: Efficient high power, solid state amplifier for EFH communications

Science.gov (United States)

Benet, James

1993-01-01

The final report describes the work performed from 9 Jun. 1992 to 31 Jul. 1993 on the NASA Satellite Communications Application Research (SCAR) Phase 2 program, Efficient High Power, Solid State Amplifier for EHF Communications. The purpose of the program was to demonstrate the feasibility of high-efficiency, high-power, EHF solid state amplifiers that are smaller, lighter, more efficient, and less costly than existing traveling wave tube (TWT) amplifiers by combining the output power from up to several hundred solid state amplifiers using a unique orthomode spatial power combiner (OSPC).

78 FR 19172 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...

Science.gov (United States)

2013-03-29

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 2 and 25 [IB Docket No. 12-376; FCC 12-161] Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit Space Stations... the Federal Register of March 8, 2013. The document proposed rules for Earth Stations Aboard Aircraft...

Network-Centric Maritime Radiation Awareness and Interdiction Experiments: C2 Experimentation

International Nuclear Information System (INIS)

Bordetsky, A; Dougan, A D; Nekoogar, F

2006-01-01

The paper addresses technological and operational challenges of developing a global plug-and-play Maritime Domain Security testbed for the Global War on Terrorism mission. This joint NPS-LLNL project is based on the NPS Tactical Network Topology (TNT) composed of long-haul OFDM networks combined with self-forming wireless mesh links to air, surface, ground, and underwater unmanned vehicles. This long-haul network is combined with ultra-wideband (UWB) communications systems for wireless communications in harsh radio propagation channels. LLNL's UWB communication prototypes are designed to overcome shortcomings of the present narrowband communications systems in heavy metallic and constricted corridors inside ships. In the center of our discussion are networking solutions for the Maritime Interdiction Operation (MIO) Experiments in which geographically distributed command centers and subject matter experts collaborate with the Boarding Party in real time to facilitate situational understanding and course of action selection. The most recent experiment conducted via the testbed extension to the Alameda Island exercised several key technologies aimed at improving MIO. These technologies included UWB communications from within the ship to Boarding Party leader sending data files and pictures, advanced radiation detection equipment for search and identification, biometric equipment to record and send fingerprint files to facilitate rapid positive identification of crew members, and the latest updates of the NPS Tactical Network Topology facilitating reachback to LLNL, Biometric Fusion Center, USCG, and DTRA experts

Interim Service ISDN Satellite (ISIS) simulator development for advanced satellite designs and experiments

Science.gov (United States)

Pepin, Gerard R.

1992-01-01

The simulation development associated with the network models of both the Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) and the Full Service ISDN Satellite (FSIS) architectures is documented. The ISIS Network Model design represents satellite systems like the Advanced Communications Technology Satellite (ACTS) orbiting switch. The FSIS architecture, the ultimate aim of this element of the Satellite Communications Applications Research (SCAR) Program, moves all control and switching functions on-board the next generation ISDN communications satellite. The technical and operational parameters for the advanced ISDN communications satellite design will be obtained from the simulation of ISIS and FSIS engineering software models for their major subsystems. Discrete event simulation experiments will be performed with these models using various traffic scenarios, design parameters, and operational procedures. The data from these simulations will be used to determine the engineering parameters for the advanced ISDN communications satellite.

Exploring the boundaries of quantum mechanics: advances in satellite quantum communications.

Science.gov (United States)

Agnesi, Costantino; Vedovato, Francesco; Schiavon, Matteo; Dequal, Daniele; Calderaro, Luca; Tomasin, Marco; Marangon, Davide G; Stanco, Andrea; Luceri, Vincenza; Bianco, Giuseppe; Vallone, Giuseppe; Villoresi, Paolo

2018-07-13

Recent interest in quantum communications has stimulated great technological progress in satellite quantum technologies. These advances have rendered the aforesaid technologies mature enough to support the realization of experiments that test the foundations of quantum theory at unprecedented scales and in the unexplored space environment. Such experiments, in fact, could explore the boundaries of quantum theory and may provide new insights to investigate phenomena where gravity affects quantum objects. Here, we review recent results in satellite quantum communications and discuss possible phenomena that could be observable with current technologies. Furthermore, stressing the fact that space represents an incredible resource to realize new experiments aimed at highlighting some physical effects, we challenge the community to propose new experiments that unveil the interplay between quantum mechanics and gravity that could be realizable in the near future.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'. © 2018 The Author(s).

The 30/20 GHz experimental communications satellite system

Science.gov (United States)

Sivo, J. N.

NASA is continuing to pursue an agressive satellite communications technology development program focused on the 30/20 GHz frequency band. A review of the program progress to date is presented. Included is a discussion of the technology program status as well as a description of the experimental system concept under study. Expected system performance characteristics together with spacecraft and payload configuration details including weight and power budget is presented. Overall program schedules of both the technology development and the flight system development are included.

Communications satellite business ventures - Measuring the impact of technology programmes and related policies

Science.gov (United States)

Greenberg, J. S.

1986-01-01

An economic evaluation and planning procedure which assesses the effects of various policies on fixed satellite business ventures is described. The procedure is based on a stochastic financial simulation model, the Domsat II, which evaluates spacecraft reliability, market performance, and cost uncertainties. The application of the Domsat II model to the assessment of NASA's ion thrusters for on-orbit propulsion and GaAs solar cell technology is discussed. The effects of insurance rates and the self-insurance option on the financial performance of communication satellite business ventures are investigated. The selection of a transportation system for placing the satellites into GEO is analyzed.

The Maritime Potential of ASEAN Economies

Directory of Open Access Journals (Sweden)

Hans-Dieter Evers

2011-01-01

Full Text Available Countries may utilize a long coastline in relation to their landmass as a resource to develop their maritime economy. This paper argues that ASEAN countries differ in utilizing their maritime potential. As a basis for further comparative studies the Center for Policy Research and International Studies (CenPRIS in Penang developed a set of indicators to measure the maritime potential of nations, the state of their maritime industries, and the degree to which the maritime potential has actually been utilized. Using the CenPRIS Ocean Index (COI shows that Brunei and the Philippines have underutilized their maritime potentials, whereas Singapore and Thailand have made full use of it. Malaysia still has the potential to further develop its maritime economy.

Lessons learned after one year in space for the AAUSAT3 satellite

DEFF Research Database (Denmark)

Larsen, Jesper Abildgaard; Mortensen, Hans Peter; Jessen, Troels

2014-01-01

The AAUSAT3 satellite is a 1U cubesat, which has been developed by students at Aalborg University, Denmark in collaboration with the Danish Maritime Authority. The satellite was launched into a polar DD-SSO orbit of 800 km altitude on February 25th 2013 on a mission to monitor ships from space...

R&D of a Next Generation LEO System for Global Multimedia Mobile Satellite Communications

Science.gov (United States)

Morikawa, E.; Motoyoshi, S.; Koyama, Y.; Suzuki, R.; Yasuda, Y.

2002-01-01

Next-generation LEO System Research Center (NeLS) was formed in the end of 1997 as a research group under the Telecommunications Advancement Organization of Japan, in cooperation with the telecommunications operators, manufacturers, universities and governmental research organization. The aim of this project is to develop new technology for global multimedia mobile satellite communications services with a user data rate around 2Mbps for handy terminals. component of the IMT-2000, and the second generation of the big-LEO systems. In prosecuting this project, two-phase approach, phase 1 and phase 2, is considered. Phase 1 is the system definition and development of key technologies. In Phase 2, we plan to verify the developed technology in Phase 1 on space. From this year we shifted the stage to Phase 2, and are now developing the prototype of on-board communication systems for flight tests, which will be planed at around 2006. The satellite altitude is assumed to be 1200 km in order to reduce the number of satellites, to avoid the Van Allen radiation belts and to increase the minimum elevation angle. Ten of the circular orbits with 55 degree of inclination are selected to cover the earth surface from -70 to 70 degree in latitude. 12 satellites are positioned at regular intervals in each orbit. In this case, the minimum elevation angle from the user terminal can be keep more than 20 degree for the visibility of the satellite, and 15 degree for simultaneous visibility of two satellites. Then, NeLS Research Center was focusing on the development of key technologies as the phase 1 project. Four kinds of key technologies; DBF satellite antenna, optical inter-satellite link system, satellite network technology with on-board ATM switch and variable rate modulation were selected. Satellite Antenna Technology: Development of on-board direct radiating active phased array antenna with digital beam forming technology would be one of the most important breakthroughs for the

Modern Advances to the Modular Fly-Away Kit (MFLAK) to Support Maritime Interdiction Operations

National Research Council Canada - National Science Library

Cross, Eric C

2007-01-01

This thesis will test the performance of an end-to-end network solution designed to augment Maritime Interdiction Operations that support boarding parties and their near real time communications with supporting agencies...

Supporting the Maritime Information Dominance: Optimizing Tactical Network for Biometric Data Sharing in Maritime Interdiction Operations

Science.gov (United States)

2015-03-01

biometric data collection. Capture role- player mock biometric data including finger prints, iris scans, and facial recognition photos. (MOC training...MARITIME INFORMATION DOMINANCE: OPTIMIZING TACTICAL NETWORK FOR BIOMETRIC DATA SHARING IN MARITIME INTERDICTION OPERATIONS by Adam R. Sinsel...MARITIME INFORMATION DOMINANCE: OPTIMIZING TACTICAL NETWORK FOR BIOMETRIC DATA SHARING IN MARITIME INTERDICTION OPERATIONS 6. AUTHOR(S) Adam R

More About Lens Antenna For Mobile/Satellite Communication

Science.gov (United States)

Rahmat-Samii, Y.; Bodnar, D. G.; Rainer, B. K.

1990-01-01

Report presents additional details of design of proposed phased-array antenna described in "Lens Antenna for Mobile/Satellite Communication" (NPO-16948). Intended to be compact and to lie flat on top of vehicle on ground. Transmits and receives circularly polarized radiation in frequency ranges of 821 to 825 MHz and 860 to 870 MHz. Transmitting and receiving beams electronically steerable to any of 48 evenly spaced directions to provide complete azimuth coverage, and would be fixed, but wide, in elevation, to provide coverage at elevation angles from 20 degrees to 60 degrees.

Dialing long distance : communications to northern operations like the MGP require sophisticated satellite networks for voice, data

Energy Technology Data Exchange (ETDEWEB)

Cook, D.

2006-04-15

Telecommunications will play a major role in the construction of the Mackenzie Gas Project due to the remoteness of its location and the volume of communication data required to support the number of people involved and the amount of construction activity. While suppliers for communications tools have not yet been identified, initial telecommunications plans call for the installation of communication equipment at all camps, major facility sites and construction locations. Equipment will be housed in self-contained, climate-controlled buildings called telecommunication service modules (TSMs), which will be connected to each other as well as to existing public communications networks. The infrastructure will support telephone and fax systems; Internet and electronic mail services; multiple channel very high frequency radios; air-to-ground communication at airstrips and helipads; ship-to-shore at barge landings; closed circuit television; satellite community antenna television; CBC radio broadcast; public address systems; security systems; and supervisory control and data acquisition (SCADA) systems. An Internet Protocol (IP) network with a voice telephone system will be implemented along with a geostationary orbit satellite network. Satellite servers and real-time data services will be used. Car kits that allow call and battery-operated self-contained telemetry devices designed to communicate via a satellite system have been commissioned for the project that are capable of providing cost-efficient and reliable asset tracking and fleet management in remote regions and assisting in deployment requirements. It was concluded that many of today's mega-projects are the driving factors behind new telecommunications solutions in remote areas. 1 fig.

A Mobile Communications Space Link Between the Space Shuttle Orbiter and the Advanced Communications Technology Satellite

Science.gov (United States)

Fink, Patrick; Arndt, G. D.; Bondyopadhyay, P.; Shaw, Roland

1994-01-01

A communications experiment is described as a link between the Space Shuttle Orbiter (SSO) and the Advanced Communications Technology Satellite (ACTS). Breadboarding for this experiment has led to two items with potential for commercial application: a 1-Watt Ka-band amplifier and a Ka-band, circularly polarized microstrip antenna. Results of the hybrid Ka-band amplifier show gain at 30 dB and a saturated output power of 28.5 dBm. A second version comprised of MMIC amplifiers is discussed. Test results of the microstrip antenna subarray show a gain of approximately 13 dB and excellent circular polarization.

Equalization and detection for digital communication over nonlinear bandlimited satellite communication channels. Ph.D. Thesis

Science.gov (United States)

Gutierrez, Alberto, Jr.

1995-01-01

This dissertation evaluates receiver-based methods for mitigating the effects due to nonlinear bandlimited signal distortion present in high data rate satellite channels. The effects of the nonlinear bandlimited distortion is illustrated for digitally modulated signals. A lucid development of the low-pass Volterra discrete time model for a nonlinear communication channel is presented. In addition, finite-state machine models are explicitly developed for a nonlinear bandlimited satellite channel. A nonlinear fixed equalizer based on Volterra series has previously been studied for compensation of noiseless signal distortion due to a nonlinear satellite channel. This dissertation studies adaptive Volterra equalizers on a downlink-limited nonlinear bandlimited satellite channel. We employ as figure of merits performance in the mean-square error and probability of error senses. In addition, a receiver consisting of a fractionally-spaced equalizer (FSE) followed by a Volterra equalizer (FSE-Volterra) is found to give improvement beyond that gained by the Volterra equalizer. Significant probability of error performance improvement is found for multilevel modulation schemes. Also, it is found that probability of error improvement is more significant for modulation schemes, constant amplitude and multilevel, which require higher signal to noise ratios (i.e., higher modulation orders) for reliable operation. The maximum likelihood sequence detection (MLSD) receiver for a nonlinear satellite channel, a bank of matched filters followed by a Viterbi detector, serves as a probability of error lower bound for the Volterra and FSE-Volterra equalizers. However, this receiver has not been evaluated for a specific satellite channel. In this work, an MLSD receiver is evaluated for a specific downlink-limited satellite channel. Because of the bank of matched filters, the MLSD receiver may be high in complexity. Consequently, the probability of error performance of a more practical

NASA satellite communications application research, phase 2 addendum. Efficient high power, solid state amplifier for EHF communications

Science.gov (United States)

Benet, James

1994-01-01

This document is an addendum to the NASA Satellite Communications Application Research (SCAR) Phase 2 Final Report, 'Efficient High Power, Solid State Amplifier for EHF Communications.' This report describes the work performed from 1 August 1993 to 11 March 1994, under contract number NASW-4513. During this reporting period an array of transistor amplifiers was repaired by replacing all MMIC amplifier chips. The amplifier array was then tested using three different feedhorn configurations. Descriptions, procedures, and results of this testing are presented in this report, and conclusions are drawn based on the test results obtained.

47 CFR 80.1069 - Maritime sea areas.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Maritime sea areas. 80.1069 Section 80.1069... MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) General Provisions § 80.1069 Maritime... continuous DSC alerting is available as defined by the International Maritime Organization. (2) Sea area A2...

Attitude Control Subsystem for the Advanced Communications Technology Satellite

Science.gov (United States)

Hewston, Alan W.; Mitchell, Kent A.; Sawicki, Jerzy T.

1996-01-01

This paper provides an overview of the on-orbit operation of the Attitude Control Subsystem (ACS) for the Advanced Communications Technology Satellite (ACTS). The three ACTS control axes are defined, including the means for sensing attitude and determining the pointing errors. The desired pointing requirements for various modes of control as well as the disturbance torques that oppose the control are identified. Finally, the hardware actuators and control loops utilized to reduce the attitude error are described.

INTERNET COMMERCE IN MARITIME INDUSTRY

Directory of Open Access Journals (Sweden)

Monika Szyda

2014-06-01

Full Text Available Internet commerce in Poland is growing rapidly, entering into new industries and of-fering a wider and wider range of goods and services. For electronic commerce is open maritime industry, as evidenced by the maritime e-commerce. This aspect of e-commerce is not a popular topic of publications and research. In this article the author presents the genesis of electronic commerce in the maritime industry taking into account the particular business relationship business-to-business (B2B. Then attempt to characterize maritime e-commerce in business-to-customer (B2C relationship. The purpose of this article is to identify the attributes of internet commerce in the maritime industry, having particular re-gard to Polish online market, especially retail.

The impact of customer-contractor interactions on spacecraft innovation: Insights from communication satellite history

Science.gov (United States)

Szajnfarber, Zoe; Stringfellow, Margaret V.; Weigel, Annalisa L.

2010-11-01

This paper captures a first detailed attempt to quantitatively analyze the innovation history of the space sector. Building on a communication satellite innovation metric and a spacecraft innovation framework developed as part of an ongoing project, this paper presents a preliminary model of global communication satellite innovation. In addition to innovation being a function of the rate of performance normalized by price, innovation was found to be strongly influenced by characteristics of the customer-contractor contractual relationship. Specifically, Department of Defense contracts tend to result in a lower level of innovation on average as compared to other customers. Also, particular customer-contractor pairs perform differently and exhibit a second order relationship in time.

Mitigating Aviation Communication and Satellite Orbit Operations Surprises from Adverse Space Weather

Science.gov (United States)

Tobiska, W. Kent

2008-01-01

Adverse space weather affects operational activities in aviation and satellite systems. For example, large solar flares create highly variable enhanced neutral atmosphere and ionosphere electron density regions. These regions impact aviation communication frequencies as well as precision orbit determination. The natural space environment, with its dynamic space weather variability, is additionally changed by human activity. The increase in orbital debris in low Earth orbit (LEO), combined with lower atmosphere CO2 that rises into the lower thermosphere and causes increased cooling that results in increased debris lifetime, adds to the environmental hazards of navigating in near-Earth space. This is at a time when commercial space endeavors are posed to begin more missions to LEO during the rise of the solar activity cycle toward the next maximum (2012). For satellite and aviation operators, adverse space weather results in greater expenses for orbit management, more communication outages or aviation and ground-based high frequency radio used, and an inability to effectively plan missions or service customers with space-based communication, imagery, and data transferal during time-critical activities. Examples of some revenue-impacting conditions and solutions for mitigating adverse space weather are offered.

Network-Centric Maritime Radiation Awareness and Interdiction Experiments: C2 Experimentation

Energy Technology Data Exchange (ETDEWEB)

Bordetsky, A; Dougan, A D; Nekoogar, F

2006-08-07

The paper addresses technological and operational challenges of developing a global plug-and-play Maritime Domain Security testbed for the Global War on Terrorism mission. This joint NPS-LLNL project is based on the NPS Tactical Network Topology (TNT) composed of long-haul OFDM networks combined with self-forming wireless mesh links to air, surface, ground, and underwater unmanned vehicles. This long-haul network is combined with ultra-wideband (UWB) communications systems for wireless communications in harsh radio propagation channels. LLNL's UWB communication prototypes are designed to overcome shortcomings of the present narrowband communications systems in heavy metallic and constricted corridors inside ships. In the center of our discussion are networking solutions for the Maritime Interdiction Operation (MIO) Experiments in which geographically distributed command centers and subject matter experts collaborate with the Boarding Party in real time to facilitate situational understanding and course of action selection. The most recent experiment conducted via the testbed extension to the Alameda Island exercised several key technologies aimed at improving MIO. These technologies included UWB communications from within the ship to Boarding Party leader sending data files and pictures, advanced radiation detection equipment for search and identification, biometric equipment to record and send fingerprint files to facilitate rapid positive identification of crew members, and the latest updates of the NPS Tactical Network Topology facilitating reachback to LLNL, Biometric Fusion Center, USCG, and DTRA experts.

Occupational asthma in maritime environments

DEFF Research Database (Denmark)

Lucas, David; Loddé, Brice; Jepsen, Jørgen Riis

2016-01-01

In 2006 we published our first review based on the available literature on occupational asthma in maritime environments in the “International Maritime Health” journal. Since then, we have obtained a great deal of new knowledge on asthma in seafood workers and fishermen and on the impact...... of exposures from sulphites preservatives, container fumigants etc. in maritime workers. This review aims to provide an update of the current knowledge base about occupational asthma in a maritime context and to provide recommendations regarding medical surveillance of workers at risk....

Ad hoc Sensor Networks to Support Maritime Interdiction Operations

OpenAIRE

Osmundson, John; Bordetsky, Alex

2014-01-01

Networking sensors, decision centers, and boarding parties supports success in Maritime Interdiction Operations. Led by a team from Naval Post-graduate School (NPS), experiments were conducted in 2012 to test the use of ad-hoc, self-forming communication networks to link sensors, people, and decision centers. The experiments involved international participants and successfully shared valuable biometric and radiological sensor data between boarding parties and decis...

The Future of Satellite Communications Technology.

Science.gov (United States)

Nowland, Wayne

1985-01-01

Discusses technical advances in satellite technology since the 1960s, and the International Telecommunications Satellite Organization's role in these developments; describes how AUSSAT, Australia's domestic satellite system, exemplifies the latest developments in satellite technology; and reviews satellite system features, possible future…

A description of QUALCOMM Automatic Satellite Position Reporting (QASPR(R)) for mobile communications

Science.gov (United States)

Ames, William G.

1990-01-01

Two satellite position reporting has been introduced into the OmniTRACS mobile satellite communication system. This system significantly improves position reporting reliability and accuracy while simplifying the terminal's hardware. The positioning technique uses the original OmniTRACS TDMA timing signal formats in the forward and return link directions plus an auxiliary, low power forward link signal through a second satellite to derive distance values. The distances are then converted into the mobile terminal's latitude and longitude in real time. A minor augmentation of the spread spectrum profile of the return link allowed the resolution of periodic ambiguities. The system also locates the two satellites in real time with fixed platforms in known locations using identical mobile terminal hardware. Initial accuracies of 1/4 mile have been realized uniformly throughout the USA using a satellite separation of 22 degrees and there are no dead zones, skywaves, or cycle slips as found in terrestrial systems like LORAN-C.

Accuracy and coverage of the modernized Polish Maritime differential GPS system

Science.gov (United States)

Specht, Cezary

2011-01-01

The DGPS navigation service augments The NAVSTAR Global Positioning System by providing localized pseudorange correction factors and ancillary information which are broadcast over selected marine reference stations. The DGPS service position and integrity information satisfy requirements in coastal navigation and hydrographic surveys. Polish Maritime DGPS system has been established in 1994 and modernized (in 2009) to meet the requirements set out in IMO resolution for a future GNSS, but also to preserve backward signal compatibility of user equipment. Having finalized installation of the new technology L1, L2 reference equipment performance tests were performed.The paper presents results of the coverage modeling and accuracy measuring campaign based on long-term signal analyses of the DGPS reference station Rozewie, which was performed for 26 days in July 2009. Final results allowed to verify the coverage area of the differential signal from reference station and calculated repeatable and absolute accuracy of the system, after the technical modernization. Obtained field strength level area and position statistics (215,000 fixes) were compared to past measurements performed in 2002 (coverage) and 2005 (accuracy), when previous system infrastructure was in operation.So far, no campaigns were performed on differential Galileo. However, as signals, signal processing and receiver techniques are comparable to those know from DGPS. Because all satellite differential GNSS systems use the same transmission standard (RTCM), maritime DGPS Radiobeacons are standardized in all radio communication aspects (frequency, binary rate, modulation), then the accuracy results of differential Galileo can be expected as a similar to DGPS.Coverage of the reference station was calculated based on unique software, which calculate the signal strength level based on transmitter parameters or field signal strength measurement campaign, done in the representative points. The software works

Study on networking issues of medium earth orbit satellite communications systems

Science.gov (United States)

Araki, Noriyuki; Shinonaga, Hideyuki; Ito, Yasuhiko

1993-01-01

Two networking issues of communications systems with medium earth orbit (MEO) satellites, namely network architectures and location determination and registration methods for hand-held terminals, are investigated in this paper. For network architecture, five candidate architectures are considered and evaluated in terms of signaling traffic. For location determination and registration, two methods are discussed and evaluated.

Optical intersatellite links - Application to commercial satellite communications

Science.gov (United States)

Paul, D.; Faris, F.; Garlow, R.; Inukai, T.; Pontano, B.; Razdan, R.; Ganz, Aura; Caudill, L.

1992-01-01

Application of optical intersatellite links for commercial satellite communications services is addressed in this paper. The feasibility of commercialization centers around basic issues such as the need and derived benefits, implementation complexity and overall cost. In this paper, commercialization of optical ISLs is assessed in terms of the services provided, systems requirements and feasibility of appropriate technology. Both long- and short-range ISLs for GEO-GEO, GEO-LEO and LEO applications are considered. Impact of systems requirements on the payload design and use of advanced technology in reducing its mass, power, and volume requirements are discussed.

Maritime Cyber Security University Research

Science.gov (United States)

2016-05-01

i Classification | CG-926 RDC | author | audience | month year Maritime Cyber Security University Research Phase I - Final Report...Distribution Statement A: Approved for public release; distribution is unlimited. May 2016 Report No. CG-D-06-16 Maritime Cyber Security...Director United States Coast Guard Research & Development Center 1 Chelsea Street New London, CT 06320 Maritime Cyber Security University

Quantum communication for satellite-to-ground networks with partially entangled states

International Nuclear Information System (INIS)

Chen Na; Quan Dong-Xiao; Pei Chang-Xing; Yang-Hong

2015-01-01

To realize practical wide-area quantum communication, a satellite-to-ground network with partially entangled states is developed in this paper. For efficiency and security reasons, the existing method of quantum communication in distributed wireless quantum networks with partially entangled states cannot be applied directly to the proposed quantum network. Based on this point, an efficient and secure quantum communication scheme with partially entangled states is presented. In our scheme, the source node performs teleportation only after an end-to-end entangled state has been established by entanglement swapping with partially entangled states. Thus, the security of quantum communication is guaranteed. The destination node recovers the transmitted quantum bit with the help of an auxiliary quantum bit and specially defined unitary matrices. Detailed calculations and simulation analyses show that the probability of successfully transferring a quantum bit in the presented scheme is high. In addition, the auxiliary quantum bit provides a heralded mechanism for successful communication. Based on the critical components that are presented in this article an efficient, secure, and practical wide-area quantum communication can be achieved. (paper)

International research collaboration in maritime health

DEFF Research Database (Denmark)

Jensen, Olaf Chresten

2011-01-01

. The area is regulated by international standards based on international research-based knowledge on health and safety. Moreover, many of the world's seafarers come from developing countries with specific disease problems like HIV and no possibility of independent maritime health research. The international......The new ILO-2006-convention and the EU Commission's strategic objectives for the EU maritime transport policy 2008-2018, mentions the necessity of a modern health and safety system for maritime transportation. However, there is no specific strategy for the development of maritime health and safety...... maritime health research is sparse, and an increase in such research is necessary to help benefit needed shipping as a highly globalized industry. This paper presents an example of such research, accompanied by a discussion of methods and opportunities to increase international maritime health research....

Millimeter wave propagation modeling of inhomogeneous rain media for satellite communications systems

Science.gov (United States)

Persinger, R. R.; Stutzman, W. L.

1978-01-01

A theoretical propagation model that represents the scattering properties of an inhomogeneous rain often found on a satellite communications link is presented. The model includes the scattering effects of an arbitrary distribution of particle type (rain or ice), particle shape, particle size, and particle orientation within a given rain cell. An associated rain propagation prediction program predicts attenuation, isolation and phase shift as a function of ground rain rate. A frequency independent synthetic storm algorithm is presented that models nonuniform rain rates present on a satellite link. Antenna effects are included along with a discussion of rain reciprocity. The model is verified using the latest available multiple frequency data from the CTS and COMSTAR satellites. The data covers a wide range of frequencies, elevation angles, and ground site locations.

Economics of satellite communications systems

Science.gov (United States)

Pritchard, Wilbur L.

This paper is partly a tutorial, telling systematically how one goes about calculating the total annual costs of a satellite communications system, and partly the expression of some original ideas on the choice of parameters so as to minimize these costs. The calculation of costs can be divided into two broad categories. The first is technical and is concerned with estimating what particular equipment will cost and what will be the annual expense to maintain and operate it. One starts in the estimation of any new system by listing the principal items of equipment, such as satellites, earth stations of various sizes and functions, telemetry and tracking equipment and terrestrial interfaces, and then estimating how much each item will cost. Methods are presented for generating such estimates, based on a knowledge of the gross parameters, such as antenna size, coverage area, transmitter power and information rate. These parameters determine the system performance and it is usually possible, knowing them, to estimate the costs of the equipment rather well. Some formulae based on regression analyses are presented. Methods are then given for estimating closely related expenses, such as maintenance and operation, and then an approximate method is developed for estimating terrestrial interconnection costs. It is pointed out that in specific cases when tariff and geographical information are available, it is usually better to work with specific data, but nonetheless it is often desirable, especially in global system estimating, to approximate these interconnect costs without recourse to individual tariffs. The procedure results in a set of costs for the purchase of equipment and its maintenance, and a schedule of payments. Some payments will be incurred during the manufacture of the satellite and before any systems operation, but many will not be incurred until the system is no longer in use, e.g. incentives. In any case, with the methods presented in the first section, one

32 CFR 537.15 - Statutory authority for maritime claims and claims involving civil works of a maritime nature.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Statutory authority for maritime claims and claims involving civil works of a maritime nature. 537.15 Section 537.15 National Defense Department of....15 Statutory authority for maritime claims and claims involving civil works of a maritime nature. (a...

Communication and Control in the Canadian North: The Role of Interactive Satellites.

Science.gov (United States)

Valaskakis, Gail G.

In 1972 the Canadian government launched its first domestic communications satellite, Anik A, which relays direct broadcast television and telephone messages to northern communities. The impact of television on Inuit life has raised issues and concerns pertaining to native language broadcasting, media access and control, and cultural identity…

Maritime Geo-Fence Letter Report

Science.gov (United States)

2016-07-01

1 Classification | CG-926 RDC | author | audience | month year Maritime Geo-Fence Letter Report Authors: Irene Gonin and Gregory...Johnson   Distribution Statement A: Approved for public release; distribution is unlimited. July 2016 Report No. CG-D-10-16 Maritime Geo-Fence...United States Coast Guard Research & Development Center 1 Chelsea Street New London, CT 06320 Maritime Geo-Fence Letter Report 1

The Maritime Engineering Education

DEFF Research Database (Denmark)

Andersen, Ingrid Marie Vincent; Nielsen, Ulrik Dam; Lützen, Marie

2012-01-01

This article describes the outcome of a survey initiated by the Danish Maritime Fund (DMF). The survey resulted in a report that describes the engineering competencies requested by the Danish maritime industry. This is of interest since the desired competencies have changed in the past one to two...... decades, where Denmark no longer has a considerable ship-building industry. Furthermore, the DMF initiated report concludes that the demand for maritime engineers in the industry is larger than the output. The report sets forth a series of recommendations to the industry as well as the universities...... to enable meeting the demand for maritime engineers in Denmark. The recommendations are outlined together with the work commenced at the Technical University of Denmark (DTU) and the University of Southern Denmark (SDU) to follow up on the recommendations in the report....

Optimization of Joint Power and Bandwidth Allocation in Multi-Spot-Beam Satellite Communication Systems

Directory of Open Access Journals (Sweden)

Heng Wang

2014-01-01

Full Text Available Multi-spot-beam technique has been widely applied in modern satellite communication systems. However, the satellite power and bandwidth resources in a multi-spot-beam satellite communication system are scarce and expensive; it is urgent to utilize the resources efficiently. To this end, dynamically allocating the power and bandwidth is an available way. This paper initially formulates the problem of resource joint allocation as a convex optimization problem, taking into account a compromise between the maximum total system capacity and the fairness among the spot beams. A joint bandwidth and power allocation iterative algorithm based on duality theory is then proposed to obtain the optimal solution of this optimization problem. Compared with the existing separate bandwidth or power optimal allocation algorithms, it is shown that the joint allocation algorithm improves both the total system capacity and the fairness among spot beams. Moreover, it is easy to be implemented in practice, as the computational complexity of the proposed algorithm is linear with the number of spot beams.

National Plan to Achieve Maritime Domain Awareness for the National Strategy for Maritime Security

National Research Council Canada - National Science Library

2005-01-01

Maritime Domain Awareness (MDA) is the effective understanding of anything associated with the global maritime domain that could impact the security, safety, economy, or environment of the United States...

Mass and power modeling of communication satellites

Science.gov (United States)

Price, Kent M.; Pidgeon, David; Tsao, Alex

1991-01-01

Analytic estimating relationships for the mass and power requirements for major satellite subsystems are described. The model for each subsystem is keyed to the performance drivers and system requirements that influence their selection and use. Guidelines are also given for choosing among alternative technologies which accounts for other significant variables such as cost, risk, schedule, operations, heritage, and life requirements. These models are intended for application to first order systems analyses, where resources do not warrant detailed development of a communications system scenario. Given this ground rule, the models are simplified to 'smoothed' representation of reality. Therefore, the user is cautioned that cost, schedule, and risk may be significantly impacted where interpolations are sufficiently different from existing hardware as to warrant development of new devices.

Defense Science Board Task Force on Military Satellite Communication and Tactical Networking. Executive Summary

Science.gov (United States)

2017-03-01

Interface Processor BCT Brigade Combat Team BFT Blue Force Tracking BLOS Beyond Line-of-Sight C2 Command And Control C2E Communications in...Satellite Communications and Tactical Networking Appendix D-2 GIG Global Information Grid GMR Ground Mobile Radio GPS Global Positioning System...System SIPRNet Secret Internet Protocol Router Network SITREPS Situational Reports SMART -T Secure Mobile Anti-Jam Reliable Tactical Terminal SMC Space

33 CFR 101.405 - Maritime Security (MARSEC) Directives.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maritime Security (MARSEC... SECURITY MARITIME SECURITY MARITIME SECURITY: GENERAL Control Measures for Security § 101.405 Maritime... necessary to respond to a threat assessment or to a specific threat against the maritime elements of the...

Prediction of Communication Outage Period between Satellite and Earth station Due to Sun Interference

Directory of Open Access Journals (Sweden)

Yongjun Song

2010-03-01

Full Text Available We developed a computer program to predict solar interference period. To calculate Sun‘s position, we used DE406 ephemerides and Earth ellipsoid model. The Sun‘s position error is smaller than 10arcsec. For the verification of the calculation, we used TU media ground station on Seongsu-dong, and MBSAT geostationary communication satellite. We analysis errors, due to satellite perturbation and antenna align. The time error due to antenna align has -35 to +16 seconds at 0.1 degree, and -27 to +41 seconds at 0.25 degree. The time errors derived by satellite perturbation has 30 to 60 seconds.

Intersatellite Link (ISL) application to commercial communications satellites. Volume 2: Technical final report

Science.gov (United States)

Young, S. Lee

1987-01-01

Intersatellite Link (ISL) applications can improve and expand communication satellite services in a number of ways. As the demand for orbital slots within prime regions of the geostationary arc increases, attention is being focused on ISLs as a method to utilize this resource more efficiently and circumvent saturation. Various GEO-to-GEO applications were determined that provide potential benefits over existing communication systems. A set of criteria was developed to assess the potential applications. Intersatellite link models, network system architectures, and payload configurations were developed. For each of the chosen ISL applications, ISL versus non-ISL satellite systems architectures were derived. Both microwave and optical ISL implementation approaches were evaluated for payload sizing and cost analysis. The technological availability for ISL implementations was assessed. Critical subsystems technology areas were identified, and an estamate of the schedule and cost to advance the technology to the requiered state of readiness was made.

Why is CDMA the solution for mobile satellite communication

Science.gov (United States)

Gilhousen, Klein S.; Jacobs, Irwin M.; Padovani, Roberto; Weaver, Lindsay A.

1989-01-01

It is demonstrated that spread spectrum Code Division Multiple Access (CDMA) systems provide an economically superior solution to satellite mobile communications by increasing the system maximum capacity with respect to single channel per carrier Frequency Division Multiple Access (FDMA) systems. Following the comparative analysis of CDMA and FDMA systems, the design of a model that was developed to test the feasibility of the approach and the performance of a spread spectrum system in a mobile environment. Results of extensive computer simulations as well as laboratory and field tests results are presented.

Effect of digital scrambling on satellite communication links

Science.gov (United States)

Dessouky, K.

1985-01-01

Digital data scrambling has been considered for communication systems using NRZ symbol formats. The purpose is to increase the number of transitions in the data to improve the performance of the symbol synchronizer. This is accomplished without expanding the bandwidth but at the expense of increasing the data bit error rate (BER). Models for the scramblers/descramblers of practical interest are presented together with the appropriate link model. The effects of scrambling on the performance of coded and uncoded links are studied. The results are illustrated by application to the Tracking and Data Relay Satellite System (TDRSS) links. Conclusions regarding the usefulness of scrambling are also given.

EUROPEAN MARITIME TRANSPORT POLICY

Directory of Open Access Journals (Sweden)

Jerzy Kujawa

2014-03-01

Full Text Available The article describes the common EU policy on maritime transport, which comprises almost 80% of the volume of external trade of the Union and about 40% of internal transport needs. The first part of the paper presents the origins of the common maritime transport policy and the difficulties encountered during its initial formation. Subsequently, the evolution of the concepts of the policy and its current shape is discussed. The final, substantial part of the article describes the main aims and directions of the EU maritime transport policy and includes an evaluation of the effects of the policy.

Radiation-hard mid-power booster optical fiber amplifiers for high-speed digital and analogue satellite laser communication links

Science.gov (United States)

Stampoulidis, L.; Kehayas, E.; Stevens, G.; Henwood-Moroney, L.; Hosking, P.; Robertson, A.

2017-11-01

Optical laser communications (OLC) has been identified as the technology to enable high-data rate, secure links between and within satellites, as well as between satellites and ground stations with decreased mass, size, and electrical power compared to traditional RF technology.

THE ANALYSIS OF HUMAN RESOURCES MANAGEMENT (HRM IN MARITIME AFFAIRS

Directory of Open Access Journals (Sweden)

Goran Vučur

2016-12-01

Full Text Available Specifics of human resources management in maritime affairs is reflected in the fact that part of the staff of enterprises is displaced on ships which represent a specific and isolated environment. Specifics of human resources management on ships are focused to decision-making in crisis situations, the deployment of personnel and work load, and giving orders to perform certain tasks. In this context it is necessary to examine the management of human resources which should include managing, motivation, rewarding, communication, education, advancement, decision-making and employee satisfaction in the specific environment. The aim of the research is to analyze the above stated parameters and connect them with the characteristics of companies in the sector of maritime logistics. The purpose of this paper is to provide an insight into the human resources management in companies involved in logistics in maritime transport i.e. delivery and transport of goods. Taking into account their differences, it can be concluded that companies in the maritime industry have different human resource management systems, which affects the company's business. The research methodology is based on the collection of data through questionnaires and databases created from them. The study included a total of 31 companies. According to the collected data, statistical analysis will be conducted which will be based on correlation and descriptive statistics. The analysis of the theoretical basis has not confirmed the existence of similar studies that take into account the observation of human resources management on ships. Therefore, it can be concluded that the research will be of interest for the field of business logistics as well as the whole scientific and professional community. Recommendations related to the current and future human resource management in maritime companies will be given in the conclusion.

Maritime Policy and the Seafaring Labor Market

DEFF Research Database (Denmark)

Lobrigo, Enrico; Pawlik, Thomas

2015-01-01

The reports highlighting the foreseen lack of merchant marine officers for the expanding world’s fleet calls for a review in evaluating the impact of maritime policy in the seafaring labor market. This paper aims to clarify the particular characteristics of the seafaring labor market and how it can...... be shaped by specific maritime labor policies. The seafaring labor market in the Philippines, Poland, Germany, and Brazil as well as the general maritime labor policies in these countries is discussed. The focus on these countries leads to a comparative observation of maritime labor as a factor...... of production in an exporting market, in an importing market, and in a closed market, respectively, as shaped by various relevant maritime policies. Since a global policy that can regulate the maritime labor market does not exist, the trend on maritime labor supply is dynamic on a per country basis wherein crew...

Interim Service ISDN Satellite (ISIS) network model for advanced satellite designs and experiments

Science.gov (United States)

Pepin, Gerard R.; Hager, E. Paul

1991-01-01

The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Network Model for Advanced Satellite Designs and Experiments describes a model suitable for discrete event simulations. A top-down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ISDN modeling abstractions are added to permit the determination and performance for the NASA Satellite Communications Research (SCAR) Program.

Maritime Education and Research to Face the XXI-st Century Challenges in Gdynia Maritime University’s Experience Part I – Maritime Universities Facing Today and Tomorrow’s Challenges

Directory of Open Access Journals (Sweden)

Janusz Mindykowski

2013-12-01

Full Text Available In the paper, divided into two parts, a problem of advancements in maritime education and research facing the 21st century challenges, based on the case study of the Gdynia Maritime University (GMU experience is discussed. Part I is devoted to the main directions of advances in the maritime education and research towards the challenges in a global meaning. In this context, the education and research potential of the Gdynia Maritime University, as one of the world-leading maritime universities, is shortly presented. Part II is dedicated to the Gdynia Maritime University experiencing the 21st century challenges. The GMU’s contribution and good practices concerning the participation in modification of the processes of the IMO STCW 78/2010 convention, adoption of programmes into the international and national qualification frameworks’ standards and procedures, as well as the development of research addressed to a new technological and organizational solution are described and analyzed.

47 CFR 25.279 - Inter-satellite service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Inter-satellite service. 25.279 Section 25.279 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.279 Inter-satellite service. (a) Any satellite communicating with other space...

China's Maritime Strategy Peaceful Rise

National Research Council Canada - National Science Library

Horrell, Steven L

2008-01-01

.... As a result the global maritime environment will be key to this continental power's continued growth As a subset of maritime strategy China's naval strategy and accompanying People's Liberation Army...

Communications satellites in the national and global health care information infrastructure: their role, impact, and issues

Science.gov (United States)

Zuzek, J. E.; Bhasin, K. B.

1996-01-01

Health care services delivered from a distance, known collectively as telemedicine, are being increasingly demonstrated on various transmission media. Telemedicine activities have included diagnosis by a doctor at a remote location, emergency and disaster medical assistance, medical education, and medical informatics. The ability of communications satellites to offer communication channels and bandwidth on demand, connectivity to mobile, remote and under served regions, and global access will afford them a critical role for telemedicine applications within the National and Global Information Infrastructure (NII/GII). The importance that communications satellites will have in telemedicine applications within the NII/GII the differences in requirements for NII vs. GII, the major issues such as interoperability, confidentiality, quality, availability, and costs, and preliminary conclusions for future usability based on the review of several recent trails at national and global levels are presented.

Documenting Maritime Folklife: An Introductory Guide.

Science.gov (United States)

Taylor, David A.

This booklet has two main purposes: (1) to promote understanding of maritime cultural heritage; and (2) to provide an introduction to the methods for identifying and documenting common maritime traditions. The guide is intended for non-professional researchers and community groups who wish to explore their own maritime cultural heritage. It also…

The Advanced Communication Technology Satellite and ISDN

Science.gov (United States)

Lowry, Peter A.

1996-01-01

This paper depicts the Advanced Communication Technology Satellite (ACTS) system as a global central office switch. The ground portion of the system is the collection of earth stations or T1-VSAT's (T1 very small aperture terminals). The control software for the T1-VSAT's resides in a single CPU. The software consists of two modules, the modem manager and the call manager. The modem manager (MM) controls the RF modem portion of the T1-VSAT. It processes the orderwires from the satellite or from signaling generated by the call manager (CM). The CM controls the Recom Laboratories MSPs by receiving signaling messages from the stacked MSP shelves ro units and sending appropriate setup commands to them. There are two methods used to setup and process calls in the CM; first by dialing up a circuit using a standard telephone handset or, secondly by using an external processor connected to the CPU's second COM port, by sending and receiving signaling orderwires. It is the use of the external processor which permits the ISDN (Integrated Services Digital Network) Signaling Processor to implement ISDN calls. In August 1993, the initial testing of the ISDN Signaling Processor was carried out at ACTS System Test at Lockheed Marietta, Princeton, NJ using the spacecraft in its test configuration on the ground.

Abbreviations in Maritime English

Science.gov (United States)

Yang, Zhirong

2011-01-01

Aiming at the phenomena that more and more abbreviations occur in maritime English correspondences, the composing laws of the abbreviations in maritime English correspondence are analyzed, and the correct methods to answer the abbreviations are pointed out, and the translation method of abbreviations are summarized in this article, and the…

Bandwidth-Efficient Communication through 225 MHz Ka-band Relay Satellite Channel

Science.gov (United States)

Downey, Joseph; Downey, James; Reinhart, Richard C.; Evans, Michael Alan; Mortensen, Dale John

2016-01-01

The communications and navigation space infrastructure of the National Aeronautics and Space Administration (NASA) consists of a constellation of relay satellites (called Tracking and Data Relay Satellites (TDRS)) and a global set of ground stations to receive and deliver data to researchers around the world from mission spacecraft throughout the solar system. Planning is underway to enhance and transform the infrastructure over the coming decade. Key to the upgrade will be the simultaneous and efficient use of relay transponders to minimize cost and operations while supporting science and exploration spacecraft. Efficient use of transponders necessitates bandwidth efficient communications to best use and maximize data throughput within the allocated spectrum. Experiments conducted with NASA's Space Communication and Navigation (SCaN) Testbed on the International Space Station provides a unique opportunity to evaluate advanced communication techniques, such as bandwidth-efficient modulations, in an operational flight system. Demonstrations of these new techniques in realistic flight conditions provides critical experience and reduces the risk of using these techniques in future missions. Efficient use of spectrum is enabled by using high-order modulations coupled with efficient forward error correction codes. This paper presents a high-rate, bandwidth-efficient waveform operating over the 225 MHz Ka-band service of the TDRS System (TDRSS). The testing explores the application of Gaussian Minimum Shift Keying (GMSK), 248-phase shift keying (PSK) and 1632- amplitude PSK (APSK) providing over three bits-per-second-per-Hertz (3 bsHz) modulation combined with various LDPC encoding rates to maximize throughput. With a symbol rate of 200 Mbaud, coded data rates of 1000 Mbps were tested in the laboratory and up to 800 Mbps over the TDRS 225 MHz channel. This paper will present on the high-rate waveform design, channel characteristics, performance results, compensation

Testing of a compact 10-Gbps Lasercomm system for maritime platforms

Science.gov (United States)

Juarez, Juan C.; Souza, Katherine T.; Nicholes, Dustin D.; Riggins, James L.; Tomey, Hala J.; Venkat, Radha A.

2017-08-01

Lasercomm technology continues to be of interest for many applications both in the commercial and defense sectors because of its potential to provide high bandwidth communications that are secure without the need for RF spectrum management. Over the last decade, terrestrial Lasercomm development has progressed from initial experiments in the lab through field demonstrations in airborne and maritime environments. While these demonstrations have shown high capability levels, the complexity, size, weight, and power of the systems has slowed transition into fielded systems. This paper presents field test results of a recently developed maritime Lasercomm terminal and modem architecture with a compact form factor for enabling robust, 10-Gbps class data transport over highly scintillated links as found in terrestrial applications such as air-to-air, air-to-surface, and surface-to-surface links.

Crosstalk cancellation on linearly and circularly polarized communications satellite links

Science.gov (United States)

Overstreet, W. P.; Bostian, C. W.

1979-01-01

The paper discusses the cancellation network approach for reducing crosstalk caused by depolarization on a dual-polarized communications satellite link. If the characteristics of rain depolarization are sufficiently well known, the cancellation network can be designed in a way that reduces system complexity, the most important parameter being the phase of the cross-polarized signal. Relevant theoretical calculations and experimental data are presented. The simplicity of the cancellation system proposed makes it ideal for use with small domestic or private earth terminals.

Do future commercial broadband communication satellites really need laser-communication intersatellite links (ISLs)?

Science.gov (United States)

Freidell, James E.

1997-04-01

Large commercial satellite programs requiring ISLs are growing in number and maturing. An important segment of the commercial satellite market, and its ISL needs, is discussed in the paper. ISL value will increase as long-haul terrestrial backbones become increasingly congested. Providing interregional and intercontinental connectivity via ISL presents far lower cost and fewer problems than relying on terrestrial fiber-optic networks. To demonstrate this, a new metric is proposed which allows 'apples-to- apples' cost/performance comparisons between laser communications in GEO, LEO, and terrestrial fiber-optics. ISL requirements in to the next decade are predicted >= 50-100 Gb/s full duplex. Many attitudinal changes must be embraced among those who choose to focus on this new commercial business. Foremost among these is a preponderance to delivering fully acceptable hardware fast and at low cost, as opposed to merely designing such. Considerable attention must be given business considerations foreign to professionals who have spent time in the government or government contracting sectors. Successful ISL customers will come to recognize that ISLs are not commodity products. Failure to embrace these attitudes will nonetheless constitute decision to which the commercial market, and particularly the financial market, will appropriately respond.

Unmanned Maritime Systems Incremental Acquisition Approach

Science.gov (United States)

2016-12-01

REPORT TYPE AND DATES COVERED MBA professional report 4. TITLE AND SUBTITLE UNMANNED MARITIME SYSTEMS INCREMENTAL ACQUISITION APPROACH 5. FUNDING...Approved for public release. Distribution is unlimited. UNMANNED MARITIME SYSTEMS INCREMENTAL ACQUISITION APPROACH Thomas Driscoll, Lieutenant...UNMANNED MARITIME SYSTEMS INCREMENTAL ACQUISITION APPROACH ABSTRACT The purpose of this MBA report is to explore and understand the issues

INTERNET COMMERCE IN MARITIME INDUSTRY

OpenAIRE

Monika Szyda

2014-01-01

Internet commerce in Poland is growing rapidly, entering into new industries and of-fering a wider and wider range of goods and services. For electronic commerce is open maritime industry, as evidenced by the maritime e-commerce. This aspect of e-commerce is not a popular topic of publications and research. In this article the author presents the genesis of electronic commerce in the maritime industry taking into account the particular business relationship business-to-business (B2B). Then at...

THE IMAGE OF PIRACY AND MARITIME TERRORISM. THE MEDIA AS A TOOL FOR ITS DEVELOPMENT

Directory of Open Access Journals (Sweden)

Piotr Gawliczek

2016-10-01

Full Text Available The subject of the article was the issue of shaping the image of piracy and maritime terrorism. Emphasis was put on the media, including those using information and communication technologies. The answers to problem questions were sought: (1 Who and why forms that image (2 what tools are used for its construction. The article presents the trends and development tendencies of the analyzed phenomena, based on the report of the United Nations Conference on Trade and Development (UNCTAD. Furthermore, the results of surveys, conducted among students of military academies, on perception of piracy and maritime terrorism, are cited.

33 CFR 104.145 - Maritime Security (MARSEC) Directive.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maritime Security (MARSEC) Directive. 104.145 Section 104.145 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARITIME SECURITY: VESSELS General § 104.145 Maritime Security (MARSEC...

33 CFR 105.145 - Maritime Security (MARSEC) Directive.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maritime Security (MARSEC) Directive. 105.145 Section 105.145 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARITIME SECURITY: FACILITIES General § 105.145 Maritime Security (MARSEC...

Research on risk assessment for maritime transport of radioactive materials. Preparation of maritime accident data for risk assessment

International Nuclear Information System (INIS)

Odano, Naoteru; Sawada, Ken-ichi; Mochiduki, Hiromitsu; Hirao, Yoshihiro; Asami, Mitsufumi

2010-01-01

Maritime transport of radioactive materials has been playing an important role in the nuclear fuel cycle in Japan. Due to recent increase of transported radioactive materials and diversification of transport packages with enlargement of nuclear research, development and utilization, safety securement for maritime transport of radioactive materials is one of important issues in the nuclear fuel cycle. Based squarely on the current circumstances, this paper summarizes discussion on importance of utilization of results of risk assessment for maritime transport of radioactive materials. A plan for development of comprehensive methodology to assess risks in maritime transport of radioactive materials is also described. Preparations of database of maritime accident to be necessary for risk assessment are also summarized. The prepared data could be utilized for future quantitative risk assessment, such as the event trees and fault trees analyses, for maritime transport of radioactive materials. The frequency of severe accident that the package might be damaged is also estimated using prepared data. (author)

Positional stabilization of communications satellites - The RITA ion propulsion system is ready for commercial use

Science.gov (United States)

The radiofrequency ion thruster assembly (RITA) intended for service aboard the new Artemis communications satellite will operate for three hours twice a day, in order to furnish orbital position adjustments that keep antennas accurately pointed toward the earth. These engines are, despite such frequent and sustained use, projected to eject no more than 30 kG of Xe over the course of a decade. RITA operation is also extremely reliable and, due to its very low propellant consumption, is the basis of a long satellite service life. RITA will be among the 15 experiments that are to be performed by ESA's Eureca research satellite.

Virtual target tracking (VTT) as applied to mobile satellite communication networks

Science.gov (United States)

Amoozegar, Farid

1999-08-01

Traditionally, target tracking has been used for aerospace applications, such as, tracking highly maneuvering targets in a cluttered environment for missile-to-target intercept scenarios. Although the speed and maneuvering capability of current aerospace targets demand more efficient algorithms, many complex techniques have already been proposed in the literature, which primarily cover the defense applications of tracking methods. On the other hand, the rapid growth of Global Communication Systems, Global Information Systems (GIS), and Global Positioning Systems (GPS) is creating new and more diverse challenges for multi-target tracking applications. Mobile communication and computing can very well appreciate a huge market for Cellular Communication and Tracking Devices (CCTD), which will be tracking networked devices at the cellular level. The objective of this paper is to introduce a new concept, i.e., Virtual Target Tracking (VTT) for commercial applications of multi-target tracking algorithms and techniques as applied to mobile satellite communication networks. It would be discussed how Virtual Target Tracking would bring more diversity to target tracking research.

76 FR 67604 - Maritime Communications

Science.gov (United States)

2011-11-02

... Specialized Mobile Radio Service, the 4.9 GHz Band Service, the Wireless Medical Telemetry Service (WMTS) and the Medical Implant Communications Service (MICS), authorized under subpart H of part 22 of this... transmit) bands. For purposes of the auction, the Commission defined a ``small'' business as an entity that...

SAW based systems for mobile communications satellites

Science.gov (United States)

Peach, R. C.; Miller, N.; Lee, M.

1993-01-01

Modern mobile communications satellites, such as INMARSAT 3, EMS, and ARTEMIS, use advanced onboard processing to make efficient use of the available L-band spectrum. In all of these cases, high performance surface acoustic wave (SAW) devices are used. SAW filters can provide high selectivity (100-200 kHz transition widths), combined with flat amplitude and linear phase characteristics; their simple construction and radiation hardness also makes them especially suitable for space applications. An overview of the architectures used in the above systems, describing the technologies employed, and the use of bandwidth switchable SAW filtering (BSSF) is given. The tradeoffs to be considered when specifying a SAW based system are analyzed, using both theoretical and experimental data. Empirical rules for estimating SAW filter performance are given. Achievable performance is illustrated using data from the INMARSAT 3 engineering model (EM) processors.

Maritime Security – The Need for a Global Agreement

OpenAIRE

Dinos Stasinopoulos

2003-01-01

This note reviews US maritime security measures, outlines work carried out by international organisations and then frames maritime security within the wider context of maritime trade. Finally, it suggests the development of a Global Agreement linking security and other maritime trade-related issues. The initiative for such an agreement should be undertaken by the EU only if current International Maritime Organisation (IMO) efforts fail to produce a maritime security framework with binding req...

Maritimes and northeast pipeline update

International Nuclear Information System (INIS)

Langan, P.

1998-01-01

Efforts made by Maritimes and Northeast Pipelines to bring the benefits of natural gas to the Maritime's economy was discussed. Some background on the developments that have brought the company to where they are today and an update on all their activities were presented. These activities and operations are expected to impact and affect the region's economy in a positive way. Particular attention was paid to the company's policy on laterals and the positive effects of that policy on the development of natural gas service and future natural gas distribution business in the Maritimes

A design proposal of a certain missile tactical command system based on Beidou satellite communication and GPS positioning techniques

Science.gov (United States)

Ma, Jian; Hao, Yongsheng; Miao, Jian; Zhang, Jianmao

2007-11-01

This paper introduced a design proposal of tactical command system that applied to a kind of anti-tank missile carriers. The tactical command system was made up of embedded computer system based on PC104 bus, Linux operating system, digital military map, Beidou satellite communication equipments and GPS positioning equipments. The geographic coordinates was measured by the GPS receiver, the positioning data, commands and information were transmitted real-time between tactical command systems, tactical command systems and command center, by the Beidou satellite communication systems. The Beidou satellite communication equipments and GPS positioning equipments were integrated to an independent module, exchanging data with embedded computer through RS232 serial ports and USB ports. The decision support system software based on information fusion, calculates positioning data, geography information and battle field information synthetically, shows the position of allies and the position of enemy on the military map, and assesses the various threats of different enemy objects, educes a situation assessment and threat assessment.

32 CFR 537.16 - Scope for maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Scope for maritime claims. 537.16 Section 537.16... BEHALF OF THE UNITED STATES § 537.16 Scope for maritime claims. The Army Maritime Claims Settlement Act... claims for damage to: (1) DA-accountable properties of a kind that are within the federal maritime...

32 CFR 536.119 - Scope for maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Scope for maritime claims. 536.119 Section 536... CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.119 Scope for maritime claims. The AMCSA applies...) Damage that is maritime in nature and caused by tortious conduct of U.S. military personnel or federal...

Maritime English instruction – ensuring instructors’ competence

Directory of Open Access Journals (Sweden)

Clive Cole

2007-10-01

Full Text Available More than ninety percent of global trade is carried by sea. As a result it “has fostered an interdependency and inter-connectivity between peoples who would previously have considered themselves completely unconnected” (Mitropoulos, 2005. For the maritime industry which facilitates this activity, it is essential that a common working language, namely English, is competently used to safeguard the ship, its crew and the environment in which it sails. This presupposes that the graduates of maritime academies are well prepared and that their mentors are qualified to perform the task required by international regulations. This paper attempts to summarise a 2-year research project, funded by the International Association of Maritime Universities and completed by the authors in 2006, entitled “Profiling the Maritime English Instructor” (PROFS. It categorizes and describes the various types of Maritime English instructors presently employed at higher Maritime Education and Training institutions worldwide, defines the requirements regarding their professional qualifications in the areas of applied linguistics, methodology and the minimum maritime background knowledge demanded by the relevant international legislation, and thus provides a guideline for management and prospective instructors.

Maritime Aerosol optical properties measured by ship-borne sky radiometer

Science.gov (United States)

Aoki, K.

2017-12-01

Maritime aerosols play an important role in the earth climate change. We started the measurements of aerosol optical properties since 1994 by using ship-borne sky radiometer (POM-01 MK-II and III; Prede Co. Ltd., Japan) over the ocean. We report the results of an aerosol optical properties over the ocean by using Research Vessel of the ship-borne sky radiometers. Aerosol optical properties observation were made in MR10-02 to MR16-09 onboard the R/V Mirai, JAMSTEC. The sky radiometer measure the direct and diffuse solar radiance with seven interference filters (0.315, 0.4, 0.5, 0.675, 0.87, 0.94, and 1.02 µm). Observation interval was made every five minutes by once, only in daytime under the clear sky conditions. GPS provides the position with longitude and latitude and heading direction of the vessel, and azimuth and elevation angle of the sun. The aerosol optical properties were computed using the SKYRAD.pack version 4.2. The obtained Aerosol optical properties (Aerosol optical thickness, Ångström exponent, Single scattering albedo, and etc.) and size distribution volume clearly showed spatial and temporal variability over the ocean. Aerosol optical thickness found over the near the coast (Asia and Tropical area) was high and variable. The size distribution volume have peaks at small particles at Asian coast and large particles at Tropical coast area. We provide the information, in this presentation, on the aerosol optical properties measurements with temporal and spatial variability in the Maritime Aerosol. This project is validation satellite of GCOM-C/SGLI, JAXA and other. The GCOM-C satellite scheduled to be launched in 2017 JFY.

TYCHO: Demonstrator and operational satellite mission to Earth-Moon-Libration point EML-4 for communication relay provision as a service

Science.gov (United States)

Hornig, Andreas; Homeister, Maren

2015-03-01

In the current wake of mission plans to the Moon and to Earth-Moon Libration points (EML) by several agencies and organizations, TYCHO identifies the key role of telecommunication provision for the future path of lunar exploration. It demonstrates an interesting extension to existing communication methods to the Moon and beyond by combining innovative technology with a next frontier location and the commercial space communication sector. It is evident that all communication systems will rely on direct communication to Earth ground stations. In case of EML-2 missions around HALO orbits or bases on the far side of the Moon, it has to be extended by communication links via relay stations. The innovative approach is that TYCHO provides this relay communication to those out-of-sight lunar missions as a service. TYCHO will establish a new infrastructure for future missions and even create a new market for add-on relay services. The TMA-0 satellite is TYCHO's first phase and a proposed demonstrator mission to the Earth-Moon Libration point EML-4. It demonstrates relay services needed for automated exploratory and manned missions (Moon bases) on the rim (>90°E and >90°W) and far side surface, to lunar orbits and even to EML-2 halo orbits (satellites and space stations). Its main advantage is the permanent availability of communication coverage. This will provide full access to scientific and telemetry data and furthermore to crucial medical monitoring and safety. The communication subsystem is a platform for conventional communication but also a test-bed for optical communication with high data-rate LASER links to serve the future needs of manned bases and periodic burst data-transfer from lunar poles. The operational TMA-1 satellite is a stand-alone mission integrated into existing space communication networks to provide open communication service to external lunar missions. Therefore the long-time stable libration points EML-4 and -5 are selected to guarantee an

Overview and outlook for Maritime markets

International Nuclear Information System (INIS)

Kirstiuk, S.

1998-01-01

The potential of the Maritime provinces as being among the world leaders in manufacturing and value-added resource processing, low unemployment and steady economic growth was explored. Irving Oil and J.D. Irving Ltd., have actively participated in supporting the Sable Offshore Energy Project and Maritimes and Northeast Projects because of the promise of tremendous economic benefits the projects will have on the Maritime provinces. It was predicted that the projects will create thousands of jobs in Nova Scotia and New Brunswick, but more importantly, they will make the region more cost-effective and more competitive in the global markets. The Sable offshore project will allow Maritimers to compete internationally on a level playing field. With gas becoming available in the region, the opportunity exists to generate electricity at lower costs using natural gas turbines and co-generation facilities. Cheaper electricity will create new opportunities for further industrial expansion, more jobs and a stronger economy for the Maritime provinces

Marine radio communication from a linguistic and pragmatic ...

African Journals Online (AJOL)

Marine radio communication from a linguistic and pragmatic perspective: A view from Venezuela. ... Regional Maritime University Journal ... language for achieving an effective communication on board and between ships and shore is English.

Transregional Threats and Maritime Security Cooperation

Science.gov (United States)

2017-08-01

continue to grow. As of 2015, China’s coast guard had 205 ships, more than the combined coast guards of Japan, Vietnam, Indonesia, Malaysia , and the...raised the possibility of China assisting the Philippines in maritime security. • China has maritime security initiatives with Malaysia and...Pakistan. They have also conducted maritime safety drills with their Omani counterparts. In recent years, the IRIN has made efforts to operate well

Study on Developing a System with IP Functionality to Monitor the Status of Containers in Maritime Logistics

Directory of Open Access Journals (Sweden)

Tae Hoon Kim

2017-12-01

Full Text Available There has been increasing demand from consignors and shipping companies for real-time monitoring of maritime cargo due to increases in fresh, dangerous, and high-value cargo. Although larger carriers have developed and integrated their own systems for such real-time monitoring services, small- and medium-sized shippers are struggling with the heavy costs and workforce associated with such capability. This study introduces a system that can do real-time monitoring of the location of shipping containers and their internal status by using IP-RFID that in cludes IP functionality. This system is composed of a tag, a smart point, and a service platform.  The monitoring tags are attached to regular containers to track the opening and closing of the doors, the internal temperature, and humidity. The tags then send the data to the smart point where the GPS information is added. The data packet is then finally transmitted to the service platform for location tracking.  In particular, as the tags in this system have IP functionality like Multicast, they are capable of communicating with the users and also allow users to control them. In order to provide such functionality, the smart points can serve as a gateway between the service platform and the tag. By managing the tag’s connection information and the status of transmission at the smart point, the service platform can directly communicate with tags connected to the respective smart point. This technology could be applied in a diverse range of maritime and non-maritime areas including warehouse management. As for maritime logistics, it also often goes through ground, port, and air transportation phases. Further studies should monitor the actual performance of this equipment across the various phases of maritime logistics to empirically test the systems proposed herein.

Maritime Governance and Policy-Making

CERN Document Server

Roe, Michael

2013-01-01

A close analysis of the framework of existing governance and the existing jurisdictional arrangements for shipping and ports reveals that while policy-making is characterized by national considerations through flags, institutional representation at all jurisdictions and the inviolability of the state, the commercial, financial, legal and operational environment of the sector is almost wholly global. This governance mismatch means that in practice the maritime industry can avoid policies which it dislikes by trading nations off against one another, while enjoying the freedoms and benefits of a globalized economy. A Post-modern interpretation of this globalized society prompts suggestions for change in maritime policy-making so that the governance of the sector better matches more closely the environment in which shipping and ports operate. Maritime Governance and Policy-Making is a controversial commentary on the record of policy-making in the maritime sector and assesses whether the reason for continued polic...

MARITIME VIOLENCE : IMPLICATIONS TO MALAYSIA

Directory of Open Access Journals (Sweden)

Nurulizwan Ahmad Zubir

2014-04-01

Full Text Available Abstract Maritime Piracy has been a serious threat to the international community especially in the SoutheastAsia region. This threat has caused tremendous implications towards the world economy, environment,political stability of the nations involved because 45% of the shipping company passes through theSoutheast Asia. The worrying fact is that these attacks were committed by terrorists as well as traditionalmaritime pirates. This paper examines on the implications of maritime crime in Malaysia and discusseswhether the definition of piracy under the International Law could be applied to these attacks. Thispaper concludes that cooperation between the region’s states and the enhancement of a good securitysystem of one state are needed to combat maritime violence. Thus it is imperative that the internationallaw need to be changed in order to enhance the meaning of piracy and also to include sea terrorism. Key words: piracy, maritime, terrorist

Review of Tracktable for Satellite Maneuver Detection

Energy Technology Data Exchange (ETDEWEB)

Acquesta, Erin C.S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Valicka, Christopher G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hinga, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ehn, Carollan Beret [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-10-01

As a tool developed to translate geospatial data into geometrical descriptors, Tracktable offers a highly efficient means to detect anomalous flight and maritime behavior. Following the success of using geometrical descriptors for detecting anomalous trajectory behavior, the question of whether Tracktable could be used to detect satellite maneuvers arose. In answering this question, this re- port will introduce a brief description of how Tracktable has been used in the past, along with an introduction to the fundamental properties of astrodynamics for satellite trajectories. This will then allow us to compare the two problem spaces, addressing how easily the methods used by Tracktable will translate to orbital mechanics. Based on these results, we will then be able to out- line the current limitations as well as possible path forward for using Tracktable to detect satellite maneuvers.

Maritime environmental penal law. International and German legislation

International Nuclear Information System (INIS)

Eller, Jan Frederik

2017-01-01

The book on maritime environmental penal law discusses the following issues: part I: introduction into the importance of oceanic environment and its thread, requirement of protective measures,; part II: focus of the study and terminology: oceanic pollution, maritime environmental legislation, international legislation; part 3: international legislative regulations concerning the protection of maritime environment: avoidance of environmental pollution, maritime legislative agreements, existing protective institutions; part 4: state penal power concerning maritime environmental protection; part 5: statutory offense according to German legislation; perspectives for regulations concerning criminal acts on sea.

78 FR 31809 - National Maritime Day, 2013

Science.gov (United States)

2013-05-24

... Vol. 78 Friday, No. 101 May 24, 2013 Part VI The President Proclamation 8985--National Maritime... Maritime Day, 2013 By the President of the United States of America A Proclamation Through every chapter of... economic growth by shipping our products all around the world. On National Maritime Day, we honor the...

Multiple wavelength spectral system simulating background light noise environment in satellite laser communications

Science.gov (United States)

Lu, Wei; Sun, Jianfeng; Hou, Peipei; Xu, Qian; Xi, Yueli; Zhou, Yu; Zhu, Funan; Liu, Liren

2017-08-01

Performance of satellite laser communications between GEO and LEO satellites can be influenced by background light noise appeared in the field of view due to sunlight or planets and some comets. Such influences should be studied on the ground testing platform before the space application. In this paper, we introduce a simulator that can simulate the real case of background light noise in space environment during the data talking via laser beam between two lonely satellites. This simulator can not only simulate the effect of multi-wavelength spectrum, but also the effects of adjustable angles of field-of-view, large range of adjustable optical power and adjustable deflection speeds of light noise in space environment. We integrate these functions into a device with small and compact size for easily mobile use. Software control function is also achieved via personal computer to adjust these functions arbitrarily. Keywords:

46 CFR 5.71 - Maritime labor disputes.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Maritime labor disputes. 5.71 Section 5.71 Shipping... REGULATIONS-PERSONNEL ACTION Statement of Policy and Interpretation § 5.71 Maritime labor disputes. Under no circumstances will the Coast Guard exercise its authority for the purpose of favoring any party to a maritime...

Mobile satellite communications in the 1990's

Science.gov (United States)

Singh, Jai

1992-07-01

The evolution of Inmarsat global services from a single market and single service of the 1980's to all of the key mobile markets and a wide range of new terminals and services in the 1990's is described. An overview of existing mobile satellite services, as well as new services under implementation for introduction in the near and longer term, including a handheld satellite phone (Inmarsat-P), is provided. The initiative taken by Inmarsat in the integration of its global mobile satellite services with global navigation capability derived from GPS (Global Positioning System) and the GLONASS (Russian GPS) navigation satellite systems and the provision of an international civil overlay for GPS/GLONASS integrity and augmentation is highlighted. To complete the overview of the development of mobile satellite services in the 1990's, the known national and regional mobile satellite system plans and the various recent proposals for both orbiting and geostationary satellite systems for proving handheld satellite phone and/or data messaging services are described.

Estimating marine aerosol particle volume and number from Maritime Aerosol Network data

Directory of Open Access Journals (Sweden)

A. M. Sayer

2012-09-01

Full Text Available As well as spectral aerosol optical depth (AOD, aerosol composition and concentration (number, volume, or mass are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The "average solution" MODIS dataset agrees more closely with MAN than the "best solution" dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data. However, without accurate AOD data and prior knowledge of

On Importance of the Hypertext Use in Maritime English Teaching

OpenAIRE

Z. Bezhanovi; L. Khardina; K. Zarbazoia

2015-01-01

The aim of the given paper is to present a set of the advantages and benefits expected by the application of the hypertext technologies in Maritime English teaching. Specification of minimum standard of competence for the officers on board the ships of 500 gross tonnage or more requires “adequate knowledge of English to enable the officer to use charts and other nautical publications, to understand meteorological information and messages concerning ship’s safety and operation, to communicate ...

Modulation Classification of Satellite Communication Signals Using Cumulants and Neural Networks

Science.gov (United States)

Smith, Aaron; Evans, Michael; Downey, Joseph

2017-01-01

National Aeronautics and Space Administration (NASA)'s future communication architecture is evaluating cognitive technologies and increased system intelligence. These technologies are expected to reduce the operational complexity of the network, increase science data return, and reduce interference to self and others. In order to increase situational awareness, signal classification algorithms could be applied to identify users and distinguish sources of interference. A significant amount of previous work has been done in the area of automatic signal classification for military and commercial applications. As a preliminary step, we seek to develop a system with the ability to discern signals typically encountered in satellite communication. Proposed is an automatic modulation classifier which utilizes higher order statistics (cumulants) and an estimate of the signal-to-noise ratio. These features are extracted from baseband symbols and then processed by a neural network for classification. The modulation types considered are phase-shift keying (PSK), amplitude and phase-shift keying (APSK),and quadrature amplitude modulation (QAM). Physical layer properties specific to the Digital Video Broadcasting - Satellite- Second Generation (DVB-S2) standard, such as pilots and variable ring ratios, are also considered. This paper will provide simulation results of a candidate modulation classifier, and performance will be evaluated over a range of signal-to-noise ratios, frequency offsets, and nonlinear amplifier distortions.

Bandwidth-Efficient Communication through 225 MHz Ka-band Relay Satellite Channel

Science.gov (United States)

Downey, Joseph A.; Downey, James M.; Reinhart, Richard C.; Evans, Michael A.; Mortensen, Dale J.

2016-01-01

The communications and navigation space infrastructure of the National Aeronautics and Space Administration (NASA) consists of a constellation of relay satellites (called Tracking and Data Relay Satellites (TDRS)) and a global set of ground stations to receive and deliver data to researchers around the world from mission spacecraft throughout the solar system. Planning is underway to enhance and transform the infrastructure over the coming decade. Key to the upgrade will be the simultaneous and efficient use of relay transponders to minimize cost and operations while supporting science and exploration spacecraft. Efficient use of transponders necessitates bandwidth efficient communications to best use and maximize data throughput within the allocated spectrum. Experiments conducted with NASA's Space Communication and Navigation (SCaN) Testbed on the International Space Station provides a unique opportunity to evaluate advanced communication techniques, such as bandwidth-efficient modulations, in an operational flight system. Demonstrations of these new techniques in realistic flight conditions provides critical experience and reduces the risk of using these techniques in future missions. Efficient use of spectrum is enabled by using high-order modulations coupled with efficient forward error correction codes. This paper presents a high-rate, bandwidth-efficient waveform operating over the 225 MHz Ka-band service of the TDRS System (TDRSS). The testing explores the application of Gaussian Minimum Shift Keying (GMSK), 2/4/8-phase shift keying (PSK) and 16/32- amplitude PSK (APSK) providing over three bits-per-second-per-Hertz (3 b/s/Hz) modulation combined with various LDPC encoding rates to maximize through- put. With a symbol rate of 200 M-band, coded data rates of 1000 Mbps were tested in the laboratory and up to 800 Mbps over the TDRS 225 MHz channel. This paper will present on the high-rate waveform design, channel characteristics, performance results

Routing of platforms in a maritime surface surveillance operation

NARCIS (Netherlands)

Grob, M.J.H.B.

2006-01-01

Maritime surface surveillance is the process of obtaining and maintaining information about surface ships in a certain sea area. It is carried out by maritime platforms such as frigates, helicopters or maritime patrol aircraft. Surface surveillance plays a vital role in maritime operations like

Power attenuation characteristics as switch-over criterion in personal satellite mobile communications

Science.gov (United States)

Castro, Jonathan P.

1993-01-01

A third generation mobile system intends to support communications in all environments (i.e., outdoors, indoors at home or office and when moving). This system will integrate services that are now available in architectures such as cellular, cordless, mobile data networks, paging, including satellite services to rural areas. One way through which service integration will be made possible is by supporting a hierarchical cellular structure based on umbrella cells, macro cells, micro and pico cells. In this type of structure, satellites are part of the giant umbrella cells allowing continuous global coverage, the other cells belong to cities, neighborhoods, and buildings respectively. This does not necessarily imply that network operation of terrestrial and satellite segments interconnect to enable roaming and spectrum sharing. However, the cell concept does imply hand-off between different cell types, which may involve change of frequency. Within this propsective, the present work uses power attenuation characteristics to determine a dynamic criterion that allows smooth transition from space to terrestrial networks. The analysis includes a hybrid channel that combines Rician, Raleigh and Log Normal fading characteristics.

Maritime zones delimitation - Problems and solutions

Science.gov (United States)

Kastrisios, Christos; Tsoulos, Lysandros

2018-05-01

The delimitation of maritime zones and boundaries foreseen by the United Nations Convention on the Law of the Sea (UNCLOS) is a factor of economic growth, effective management of the coastal and ocean environment and the cornerstone for maritime spatial planning. Maritime zones and boundaries form the outermost limits of coastal states and their accurate delineation and cartographic portrayal is a matter of national priority. Although UNCLOS is a legal document, its implementation -at first place- is purely technical and requires -amongst others- theoretical and applied background on Geodesy, Cartography and Geographic Information Systems (GIS) for those involved. This paper provides a brief historical background of the evolution of the UNCLOS, presents the various concepts of the Convention and identifies the problems inherent in the maritime delimitation process. Furthermore, it presents solutions that will facilitate the cartographer's work in order to achieve unquestionable results. Through the paper it becomes evident that the role of the cartographer and the GIS expert is critical for the successful implementation of maritime delimitation.

Advanced architectures and the required technologies for next-generation communications satellite systems

Science.gov (United States)

Arnold, Ray; Naderi, F. Michael

1988-01-01

The hardware requirements for multibeam operation and onboard data processing and switching on future communication satellites are reviewed. Topics addressed include multiple-beam antennas, frequency-addressable beams, baseband vs IF switching, FDM/TDMA systems, and bulk demodulators. The proposed use of these technologies in the NASA ACTS, Italsat, and the Japanese ETS-VI is discussed in detail and illustrated with extensive diagrams, maps, drawings, and tables of projected performance data.

Maritime Cyber Security University Research: Phase 1

Science.gov (United States)

2016-05-01

i Classification | CG-926 RDC | author | audience | month year Maritime Cyber Security University Research Phase I - Final Report...Appendices Distribution Statement A: Approved for public release; distribution is unlimited. May 2016 Report No. CG-D-07-16 Maritime ...Macesker Executive Director United States Coast Guard Research & Development Center 1 Chelsea Street New London, CT 06320 Maritime Cyber Security

Short Communication. Resin tapping activity as a contribution to the management of maritime pine forest

Directory of Open Access Journals (Sweden)

Amélia Palma

2016-07-01

Full Text Available Aim of the study: In this work potential resin yield in a region of high forest ability where maritime pine is the main species was estimated in order to understand the viability of promoting resin exploitation. Area of study: This study was conducted in Castro Daire County in central region of Portugal. Material and methods: To quantify the resin yield of trees tapped for the first time two plots were installed in a maritime pine stand with average tree age 65 years. Before the beginning of the resin tapping, dendrometric tree variables were measured. Also, in a neighbouring stand, 25 trees were selected to check the relation between tree dbh and resin yield. Gum resin from every tree was weighted during the season. Estimates of potential resin yield in Castro Daire County were made based on data from National Forest Inventory plots, resin tapping legislation and resin yield values obtained in the field. Two scenarios were considered: high and low resin yield. To understand the intentions of forest owners towards restarting resin tapping activity 16 maritime pine forest owners were interviewed. Main results: The results point out a high yield potential capacity for gum resin production in the County: values between 2,025 and 5,873 tons were obtained. Research highlights: Results may highlight the important socio-economical role of the resin tapping activity and can be used to support national forest policies to the resin sector and give forest owners motivation to reactivate resin tapping activity. Keywords: non-wood forest product; resin yield potential; forest owner.

Short Communication. Resin tapping activity as a contribution to the management of maritime pine forest

Energy Technology Data Exchange (ETDEWEB)

Palma, A.; Pereira, J.M.; Soares, P.

2016-07-01

Aim of the study: In this work potential resin yield in a region of high forest ability where maritime pine is the main species was estimated in order to understand the viability of promoting resin exploitation. Area of study: This study was conducted in Castro Da ire County in central region of Portugal. Material and methods: To quantify the resin yield of trees tapped for the first time two plots were installed in a maritime pine stand with average tree age 65 years. Before the beginning of the resin tapping, dendrometric tree variables were measured. Also, in a neighbouring stand, 25 trees were selected to check the relation between tree dbh and resin yield. Gum resin from every tree was weighted during the season. Estimates of potential resin yield in Castro Daire County were made based on data from National Forest Inventory plots, resin tapping legislation and resin yield values obtained in the field. Two scenarios were considered: high and low resin yield. To understand the intentions of forest owners towards restarting resin tapping activity 16 maritime pine forest owners were interviewed. Main results: The results point out a high yield potential capacity for gum resin production in the County: values between 2,025 and 5,873 tons were obtained. Research highlights: Results may highlight the important socio-economical role of the resin tapping activity and can be used to support national forest policies to the resin sector and give forest owners motivation to reactivate resin tapping activity. (Author)

77 FR 28894 - Maritime Vulnerability Self-Assessment Tool

Science.gov (United States)

2012-05-16

... DEPARTMENT OF HOMELAND SECURITY Transportation Security Administration Maritime Vulnerability Self... maritime vulnerability self- assessment tool. SUMMARY: The Transportation Security Administration (TSA) announces that the TSA Maritime Self-Assessment Risk Module (TMSARM), developed to support the United States...

Link establishment criterion and topology optimization for hybrid GPS satellite communications with laser crosslinks

Science.gov (United States)

Li, Lun; Wei, Sixiao; Tian, Xin; Hsieh, Li-Tse; Chen, Zhijiang; Pham, Khanh; Lyke, James; Chen, Genshe

2018-05-01

In the current global positioning system (GPS), the reliability of information transmissions can be enhanced with the aid of inter-satellite links (ISLs) or crosslinks between satellites. Instead of only using conventional radio frequency (RF) crosslinks, the laser crosslinks provide an option to significantly increase the data throughput. The connectivity and robustness of ISL are needed for analysis, especially for GPS constellations with laser crosslinks. In this paper, we first propose a hybrid GPS communication architecture in which uplinks and downlinks are established via RF signals and crosslinks are established via laser links. Then, we design an optical crosslink assignment criteria considering the practical optical communication factors such as optical line- of-sight (LOS) range, link distance, and angular velocity, etc. After that, to further improve the rationality of establishing crosslinks, a topology control algorithm is formulated to optimize GPS crosslink networks at both physical and network layers. The RF transmission features for uplink and downlink and optical transmission features for crosslinks are taken into account as constraints for the optimization problem. Finally, the proposed link establishment criteria are implemented for GPS communication with optical crosslinks. The designs of this paper provide a potential crosslink establishment and topology control algorithm for the next generation GPS.

Maritime Security Concerns of the East African Community (EAC ...

African Journals Online (AJOL)

The maritime domain of the East African Community (EAC) is affected by a number of maritime security threats, including piracy, armed robbery against ships and an ongoing maritime border dispute between Kenya and Somalia. Neither the EAC nor its member States have long-term and holistic maritime security policies.

Prediction of the Sun-Glint Locations for the Communication, Ocean and Meteorological Satellite

Directory of Open Access Journals (Sweden)

Jae-Ik Park

2005-09-01

Full Text Available For the Communication, Ocean and Meteorological Satellite (COMS which will be launched in 2008, an algorithm for finding the precise location of the sun-glint point on the ocean surface is studied. The precise locations of the sun-glint are estimated by considering azimuth and elevation angles of Sun-satellite-Earth geometric position and the law of reflection. The obtained nonlinear equations are solved by using the Newton-Raphson method. As a result, when COMS is located at 116.2°E or 128.2°E longitude, the sun-glint covers region of ±10° (N-S latitude and 80-150° (E-W longitude. The diurnal path of the sun-glint in the southern hemisphere is curved towards the North Pole, and the path in the northern hemisphere is forwards the south pole. The algorithm presented in this paper can be applied to predict the precise location of sun-glint region in any other geostationary satellites.

An overview of maritime archaeological studies in India

Digital Repository Service at National Institute of Oceanography (India)

Tripati, S.

stream_size 66180 stream_content_type text/plain stream_name Maritime_contacts_of_the_past_2015_729.pdf.txt stream_source_info Maritime_contacts_of_the_past_2015_729.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset...=UTF-8 AN OVERVIEW OF MARITIME ARCHAEOLOGICAL STUDIES IN INDIA 729An overview of maritime archaeological studies in India Sila Tripati, CSIR-National Institute of Oceanography, Goa, India Trade and cultural contacts among the people...

Maritime archaeology and shipwrecks off Goa

Digital Repository Service at National Institute of Oceanography (India)

Tripati, S.; Gaur, A; Sundaresh

In recent years, maritime archaeological studies have unearthed several of our lost cultural heritages. Many believe that maritime archaeology is a complex and specialized field. Author has penned down his personal experiences in the form...

Les véhicules de l’image — données techniques sur les satellites de télécommunication

OpenAIRE

Rapp, Jean-Philippe

2016-01-01

L’atout et l’enjeu que représente le satellite dans le domaine de la détection ou de la gestion des ressources terrestres, de la météorologie, de la navigation maritime n’est déjà plus à démontrer. On connaît l’importance que les militaires et les services spéciaux lui accordent (espionnage, observation et peut-être un jour intervention directe dans un conflit). En dépit des conséquences liées à ces divers usages nous ne nous y arrêterons guère ; ces thèmes en effet mériteraient à eux seuls d...

32 CFR 536.117 - Statutory authority for maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Statutory authority for maritime claims. 536.117... ACCOUNTS CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.117 Statutory authority for maritime claims. The Army Maritime Claims Settlement Act (AMCSA) (10 U.S.C. 4801-04, 4806, as amended) authorizes the...

32 CFR 536.120 - Claims payable as maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Claims payable as maritime claims. 536.120... ACCOUNTS CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.120 Claims payable as maritime claims. A claim is cognizable under this subpart if it arises in or on a maritime location, involves some...

Maritime cleantech entrepreneurship in Frederikshavn, Denmark

DEFF Research Database (Denmark)

Hermann, Roberto Rivas; Lunde-Christensen, Jeanne Christine; Riisgaard, Henrik

2012-01-01

The demand on maritime cleantech may increase as result new regulations on maritime source air pollutants by International Maritime Organization and the European Union. As result, the demands will also increase for ship retrofit and cleantech installations. Such opportunities may be triggered...... in access to and best use of information. Furthermore, access to information can result from active search, alertness to opportunities, and entrepreneur's previous experience. The Frederikshavn case study may add a fourth element: access to information can result from the facilitation provided...

High Data Rate Satellite Communications for Environmental Remote Sensing

Science.gov (United States)

Jackson, J. M.; Munger, J.; Emch, P. G.; Sen, B.; Gu, D.

2014-12-01

Satellite to ground communication bandwidth limitations place constraints on current earth remote sensing instruments which limit the spatial and spectral resolution of data transmitted to the ground for processing. Instruments such as VIIRS, CrIS and OMPS on the Soumi-NPP spacecraft must aggregate data both spatially and spectrally in order to fit inside current data rate constraints limiting the optimal use of the as-built sensors. Future planned missions such as HyspIRI, SLI, PACE, and NISAR will have to trade spatial and spectral resolution if increased communication band width is not made available. A number of high-impact, environmental remote sensing disciplines such as hurricane observation, mega-city air quality, wild fire detection and monitoring, and monitoring of coastal oceans would benefit dramatically from enabling the downlinking of sensor data at higher spatial and spectral resolutions. The enabling technologies of multi-Gbps Ka-Band communication, flexible high speed on-board processing, and multi-Terabit SSRs are currently available with high technological maturity enabling high data volume mission requirements to be met with minimal mission constraints while utilizing a limited set of ground sites from NASA's Near Earth Network (NEN) or TDRSS. These enabling technologies will be described in detail with emphasis on benefits to future remote sensing missions currently under consideration by government agencies.

A systems approach to the commercialization of space communications technology - The NASA/JPL Mobile Satellite Program

Science.gov (United States)

Weber, William J., III; Gray, Valerie W.; Jackson, Byron; Steele, Laura C.

1991-10-01

This paper discusss the systems approach taken by NASA and the Jet Propulsion Laboratory in the commercialization of land-mobile satellite services (LMSS) in the United States. As the lead center for NASA's Mobile Satellite Program, JPL was involved in identifying and addressing many of the key barriers to commercialization of mobile satellite communications, including technical, economic, regulatory and institutional risks, or uncertainties. The systems engineering approach described here was used to mitigate these risks. The result was the development and implementation of the JPL Mobile Satellite Experiment Project. This Project included not only technology development, but also studies to support NASA in the definition of the regulatory, market, and investment environments within which LMSS would evolve and eventually operate, as well as initiatives to mitigate their associated commercialization risks. The end result of these government-led endeavors was the acceleration of the introduction of commercial mobile satellite services, both nationally and internationally.

32 CFR 536.118 - Related statutes for maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Related statutes for maritime claims. 536.118... ACCOUNTS CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.118 Related statutes for maritime claims... under the AMCSA is not mandatory for causes of action as it is for the SIAA or PVA. (b) Similar maritime...

The safety features of an integrated maritime reactor

International Nuclear Information System (INIS)

Miyakoshi, Junichi; Yamada, Nobuyuki; Kuwahara, Shin-ichi

1975-01-01

The EFDR-80, a typical integrated maritime reactor, which is being developed in West Germany is outlined. The safety features of the integrated maritime reactor are presented with the analysis of reactor accidents and hazards, and are compared with those of the separated maritime reactor. Furthermore, the safety criteria of maritime reactors in Japan and West Germany are compared, and some of the differences are presented from the viewpoint of reactor design and safety analysis. In this report the authors express an earnest desire that the definite and reasonable safety criteria of the integrated maritime reactor should be established and that the safety criteria of the nuclear ship should be standardized internationally. (auth.)

Deviations in CBERS-4 Satellite Direction Components From The Electromagnetic Disturbance of Communication Antennas

Science.gov (United States)

Heilmann, A.; Fernandes, C.

2017-10-01

The CBERS-4 is a low Earth orbit satellite, with a set of antennas S-band/UHF for communication almost omni-direcional. For the electromagnetic radiation from transmission antennas, was developed a model of electromagnetic disturbance considering the antennas theory and the laws of the conservation energy-momentum. Was propagated the orbit of the CBERS-4 satellite considering your state vector from the March 14, 2016, at 11h 14m 15.23s using the equation of motion in the form of cartesian components. From the state vector of the CBERS-4 satellite was possible to propagate the orbit for different periods, without disturbance (considering just the problem of two bodies) and with a disturbance of electromagnetic origin. The model of reaction of electromagnetic acceleration on the satellite depends on only the type of antenna. Quadrifilar and parabolic propeller antennas were considered in this paper. Using the equation of motion of the satellite based on the method of Runge-Kutta of fourth and fifth degree, the effect disturber this modeling was applied on the CBERS-4 considering the mass of satellite, characteristics of antenna, power irradiated and gain maximum of antenna. The final analysis discusses the values of components in the direction (radial, cross and normal) and the coordinates X-Y-Z considering the case disturbed to both antennas.

Maritim epidemiologi på Supercourse

DEFF Research Database (Denmark)

Jensen, Olaf

2015-01-01

Maritim epidemiologi er nu kommet med i samlingen af undervisningsmidler på ”Supercourse”. Der er oprettet en særlig mappe med Maritime Epidemiology og alle der har gode bidrag inden for området opfordres hermed til at publicere her. Supercourse er en samling af foredrag beregnet til at være en r...

A Strategic Analysis of Commercial Satellite communications Enterprises and their Role for the Warfighter of the Future

National Research Council Canada - National Science Library

Gonder, Richard

1998-01-01

.... After initially setting the baseline, the paper will discuss the ability of the exploding commercial satellite communications market to meet some, if not most of the uniquely military requirements (the pros...

Effect of Wind Speed on Aerosol Optical Depth over Remote Oceans, Based on Data from the Maritime Aerosol Network

Science.gov (United States)

Smirnov, A.; Sayer, A. M.; Holben, B. N.; Hsu, N. C.; Sakerin, S. M.; Macke, A.; Nelson, N. B.; Courcoux, Y.; Smyth, T. J.; Croot, P.;

33 CFR 106.140 - Maritime Security (MARSEC) Directive.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maritime Security (MARSEC... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES General § 106.140 Maritime Security (MARSEC) Directive. All OCS facility owners or operators subject to this part must comply...

Summary of the CTS Transient Event Counter data after one year of operation. [Communication Technology Satellite

Science.gov (United States)

Stevens, N. J.; Klinect, V. W.; Gore, J. V.

1977-01-01

The environmental charging of satellite surfaces during geomagnetic substorms is the apparent cause of a significant number of anomalous events occurring on geosynchronous satellites since the early 1970's. Electromagnetic pulses produced in connection with the differential charging of insulators can couple into the spacecraft harness and cause electronic switching anomalies. An investigation conducted to determine the response of the spacecraft surfaces to substorm particle fluxes makes use of a harness transient detector. The harness transient detector, called the Transient Event Counter (TEC) was built and integrated into the Canadian-American Communications Technology Satellite (CTS). A description of the TEC and its operational characteristics is given and the obtained data are discussed. The data show that the satellite surfaces appear to be charged to the point that discharges occur and that the discharge-induced transients couple into the wire harnesses.

The design of a linear L-band high power amplifier for mobile communication satellites

Science.gov (United States)

Whittaker, N.; Brassard, G.; Li, E.; Goux, P.

1990-01-01

A linear L-band solid state high power amplifier designed for the space segment of the Mobile Satellite (MSAT) mobile communication system is described. The amplifier is capable of producing 35 watts of RF power with multitone signal at an efficiency of 25 percent and with intermodulation products better than 16 dB below carrier.

[Mobile hospital -real time mobile telehealthcare system with ultrasound and CT van using high-speed satellite communication-].

Science.gov (United States)

Takizawa, Masaomi; Miyashita, Toyohisa; Murase, Sumio; Kanda, Hirohito; Karaki, Yoshiaki; Yagi, Kazuo; Ohue, Toru

2003-01-01

A real-time telescreening system is developed to detect early diseases for rural area residents using two types of mobile vans with a portable satellite station. The system consists of a satellite communication system with 1.5Mbps of the JCSAT-1B satellite, a spiral CT van, an ultrasound imaging van with two video conference system, a DICOM server and a multicast communication unit. The video image and examination image data are transmitted from the van to hospitals and the university simultaneously. Physician in the hospital observes and interprets exam images from the van and watches the video images of the position of ultrasound transducer on screenee in the van. After the observation images, physician explains a results of the examination by the video conference system. Seventy lung CT screening and 203 ultrasound screening were done from March to June 2002. The trial of this real time screening suggested that rural residents are given better healthcare without visit to the hospital. And it will open the gateway to reduce the medical cost and medical divide between city area and rural area.

31 CFR 538.519 - Aircraft and maritime safety.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Aircraft and maritime safety. 538.519..., Authorizations, and Statements of Licensing Policy § 538.519 Aircraft and maritime safety. Specific licenses may... aircraft, and to ensure the safety of ocean-going maritime traffic in international waters. ...

Spacecraft design project: Low Earth orbit communications satellite

Science.gov (United States)

Moroney, Dave; Lashbrook, Dave; Mckibben, Barry; Gardener, Nigel; Rivers, Thane; Nottingham, Greg; Golden, Bill; Barfield, Bill; Bruening, Joe; Wood, Dave

1991-01-01

This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities.

Impact of “smart” technologies in teaching maritime subjects

Science.gov (United States)

Barsan, E.; Varsami, C.; Duse, A.; Hanzu-Pazara, R.; Jenaru, A.

2017-08-01

Nowadays students were born in a world of continuous evolution of technology. Technology is part of their daily life inside and outside their professional studies. One of the most important discoveries when it comes to technology is the internet which provides today the possibility for students to have access to all types of information and resources which are very useful in their studies activities. Therefore, in our paper we ask a very natural question: which is the place of technology in the university studies? Moreover: What part does technology play in teaching Maritime subjects? And: Which is the impact of technology in maritime teaching? Our intention is to go into more specific details on this subject, as in trying to exemplify our observations based on our own experience in teaching in Constanta Maritime University. Further on, we intend to discuss how the so called “smart” technologies came into occupying a very important place in the daily activities of our students forcing trainers to cope with this phenomenon in order to improve their teaching activities and even their relation (communication) with their students. We chose to develop this subject because everybody needs to be aware of the huge differences between generations of students. Previous generations used to require and enjoy studying from the traditional paper resources, while present generations do not even visit the libraries anymore. This is why university lecturers need to adapt their teaching methods, teaching tools and study materials to their students’ needs and of course to the evolution of technology.

Center for Maritime Safety and Health Studies

Data.gov (United States)

Federal Laboratory Consortium — Established in November 2015, the Center for Maritime Safety and Health Studies (CMSHS) promotes safety and health for all maritime workers, including those employed...

The American Satellite Company (ASC) satellite deployed from payload bay

Science.gov (United States)

1985-01-01

The American Satellite Company (ASC) communications satellite is deployed from the payload bay of the Shuttle Discovery. A portion of the cloudy surface of the earth can be seen to the left of the frame.

The maritime transport of nuclear substances

International Nuclear Information System (INIS)

Los Santos, A. de; Corretjer, L.

1976-01-01

In view of the fact that the regulation of maritime transport of nuclear materials comes under both maritime and nuclear law has raised problems which it was attempted to solve by specific standards. As regards the prevention of nuclear hazards, these standards are based on the recommendations of competent international organizations, while concerning compensation of nuclear damage, a Convention which has just come into force lays down that nuclear law has priority over maritime law. Despite the progress made, a study of the situation in this field shows that it can be further improved. (N.E.A.) [fr

Characterization of Wildfire-Induced Aerosol Emissions From the Maritime Continent Peatland and Central African Dry Savannah with MISR and CALIPSO Aerosol Products

Science.gov (United States)

Lee, Huikyo; Jeong, Su-Jong; Kalashnikova, Olga; Tosca, Mika; Kim, Sang-Woo; Kug, Jong-Seong

2018-03-01

Aerosol plumes from wildfires affect the Earth's climate system through regulation of the radiative budget and clouds. However, optical properties of aerosols from individual wildfire smoke plumes and their resultant impact on regional climate are highly variable. Therefore, there is a critical need for observations that can constrain the partitioning between different types of aerosols. Here we present the apparent influence of regional ecosystem types on optical properties of wildfire-induced aerosols based on remote sensing observations from two satellite instruments and three ground stations. The independent observations commonly show that the ratio of the absorbing aerosols is significantly lower in smoke plumes from the Maritime Continent than those from Central Africa, so that their impacts on regional climate are different. The observed light-absorbing properties of wildfire-induced aerosols are explained by dominant ecosystem types such as wet peatlands for the Maritime Continent and dry savannah for Central Africa, respectively. These results suggest that the wildfire-aerosol-climate feedback processes largely depend on the terrestrial environments from which the fires originate. These feedbacks also interact with climate under greenhouse warming. Our analysis shows that aerosol optical properties retrieved based on satellite observations are critical in assessing wildfire-induced aerosols forcing in climate models. The optical properties of carbonaceous aerosol mixtures used by state-of-the-art chemistry climate models may overestimate emissions for absorbing aerosols from wildfires over the Maritime Continent.

47 CFR 80.469 - Maritime mobile repeater stations in Alaska.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Maritime mobile repeater stations in Alaska. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Public Coast Stations Use of Telephony § 80.469 Maritime mobile repeater stations in Alaska. (a) Maritime mobile repeater stations are authorized to extend...

29 CFR 2530.200b-6 - Maritime industry.

Science.gov (United States)

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Maritime industry. 2530.200b-6 Section 2530.200b-6 Labor... Provisions § 2530.200b-6 Maritime industry. (a) General. Sections 202(a)(3)(D), 203(b)(2)(D) and 204(b)(3)(E... provisions applicable to the maritime industry. In general, those provisions permit statutory standards...

Maritime energy and security: Synergistic maximization or necessary tradeoffs?

International Nuclear Information System (INIS)

Nyman, Elizabeth

2017-01-01

Offshore energy is big business. The traditional source of maritime energy, offshore petroleum and gas, has been on the rise since a reliable method of extraction was discovered in the mid-20th century. Lately, it has been joined by offshore wind and tidal power as alternative “green” sources of maritime energy. Yet all of this has implications for maritime environmental regimes as well, as maritime energy extraction/generation can have a negative effect on the ocean environment. This paper considers two major questions surrounding maritime energy and environmental concerns. First, how and why do these two concerns, maritime energy and environmental protection, play against each other? Second, how can states both secure their energy and environmental securities in the maritime domain? Maximizing maritime energy output necessitates some environmental costs and vice versa, but these costs vary with the type of offshore energy technology used and with the extent to which states are willing to expend effort to protect both environmental and energy security. - Highlights: • Security is a complicated concept with several facets including energy and environmental issues. • Offshore energy contributes to energy supply but can have environmental and monitoring costs. • Understanding the contribution of offshore energy to security depends on which security facet is deemed most important.

Trellis coding with Continuous Phase Modulation (CPM) for satellite-based land-mobile communications

Science.gov (United States)

1989-01-01

This volume of the final report summarizes the results of our studies on the satellite-based mobile communications project. It includes: a detailed analysis, design, and simulations of trellis coded, full/partial response CPM signals with/without interleaving over various Rician fading channels; analysis and simulation of computational cutoff rates for coherent, noncoherent, and differential detection of CPM signals; optimization of the complete transmission system; analysis and simulation of power spectrum of the CPM signals; design and development of a class of Doppler frequency shift estimators; design and development of a symbol timing recovery circuit; and breadboard implementation of the transmission system. Studies prove the suitability of the CPM system for mobile communications.

Orchestrating Transnational Environmental Governance in Maritime Shipping

DEFF Research Database (Denmark)

Lister, Jane; Taudal Poulsen, René; Ponte, Stefano

2015-01-01

Maritime shipping is the transmission belt of the global economy. It is also a major contributor to global environmental change through its under-regulated air, water and land impacts. It is puzzling that shipping is a lagging sector as it has a well-established global regulatory body—the Interna......Maritime shipping is the transmission belt of the global economy. It is also a major contributor to global environmental change through its under-regulated air, water and land impacts. It is puzzling that shipping is a lagging sector as it has a well-established global regulatory body......—the International Maritime Organization. Drawing on original empirical evidence and archival data, we introduce a four-factor framework to investigate two main questions: why is shipping lagging in its environmental governance; and what is the potential for the International Maritime Organization to orchestrate......, and growing regulatory fragmentation and uncertainty. The paper concludes with pragmatic recommendations for the International Maritime Organization to acknowledge the regulatory difficulties and seize the opportunity to orchestrate environmental progress....

Neotectonics in the maritime provinces

International Nuclear Information System (INIS)

Martin, G.L.

1988-03-01

Seismic risk assessment in the Maritime Provinces requires input from not just historical, but also geological sources. A detailed search through published and unpublished geological literature reveals many examples - some probable, some possible -of neotectonic movement in the area. Examples range in tectonic significance from those that reflect exaggerated local imbalance to those that signify deep-seated stress. Evidence for neotectonism in the Maritimes is multidisciplined. It includes deformation in bedrock and quaternary deposits, and regional warping. Recent movement also is indicated by changes in relative sea level, in situ stress fields and geodetic fluctuations. Finally, and most unequivocally, neotectonism in the Maritime Provinces is manifested as the seismic events that have sporadically affected the area throughout its recent geological history, and continue up to the present day. 288 refs

Lightning hazard region over the maritime continent observed from satellite and climate change threat

Science.gov (United States)

Ilhamsyah, Y.; Koesmaryono, Y.; Hidayat, R.; Murjaya, J.; Nurjaya, I. W.; Rizwan

2017-02-01

Climate change would lead to such hydrometeorological disaster as: flash-flood, landslide, hailstone, lightning, and twister become more likely to happen in the future. In terms of lightning event, one research question arise of where lightning would be mostly to strike over the Maritime Continent (MC)?. The objective of the research is to investigate region with high-density of lightning activity over MC by mapping climatological features of lightning flashes derived from onboard NASA-TRMM Satellite, i.e. Optical Transient Detector/Lightning Imaging Sensor (OTD/LIS). Based on data retrieved since 1995-2013, it is seasonally observed that during transition season March to May, region with high vulnerability of lightning flashes cover the entire Sumatra Island, the Malacca Strait, and Peninsular Malaysia as well as Java Island. High-frequent of lightning activity over the Malacca Strait is unique since it is the only sea-region in the world where lightning flashes are denser. As previously mentioned that strong lightning activity over the strait is driven by mesoscale convective system of Sumatra Squalls due to convergences of land breeze between Sumatra and Peninsular Malaysia. Lightning activity over the strait is continuously observed throughout season despite the intensity reduced. Java Island, most populated island, receive high-density of lightning flashes during rainy season (December to February) but small part in the northwestern of Java Island, e.g., Bogor and surrounding areas, the density of lightning flashes are high throughout season. Northern and southern parts of Kalimantan and Central part of Sulawesi are also prone to lightning activity particularly during transition season March to May and September to November. In the eastern part of MC, Papua receive denser lightning flashes during September to November. It is found that lightning activity are mostly concentrated over land instead of ocean which is in accordance with diurnal convective

Description and Simulation of a Fast Packet Switch Architecture for Communication Satellites

Science.gov (United States)

Quintana, Jorge A.; Lizanich, Paul J.

1995-01-01

The NASA Lewis Research Center has been developing the architecture for a multichannel communications signal processing satellite (MCSPS) as part of a flexible, low-cost meshed-VSAT (very small aperture terminal) network. The MCSPS architecture is based on a multifrequency, time-division-multiple-access (MF-TDMA) uplink and a time-division multiplex (TDM) downlink. There are eight uplink MF-TDMA beams, and eight downlink TDM beams, with eight downlink dwells per beam. The information-switching processor, which decodes, stores, and transmits each packet of user data to the appropriate downlink dwell onboard the satellite, has been fully described by using VHSIC (Very High Speed Integrated-Circuit) Hardware Description Language (VHDL). This VHDL code, which was developed in-house to simulate the information switching processor, showed that the architecture is both feasible and viable. This paper describes a shared-memory-per-beam architecture, its VHDL implementation, and the simulation efforts.

Data manage and communication of lunar orbital X-ray imaging analyzer in CE-1 satellite

International Nuclear Information System (INIS)

Wang Jinzhou; Wang Huanyu; Zhang Chengmo; Liang Xiaohua; Gao Min; CaoXuelei; Zhang Jiayu; Peng Wenxi; Cui Xingzhu; Xu Yupeng; Zhang Yongjie

2006-01-01

We present the software design for data management and communication software designed for the Lunar Orbital X-ray Imaging Analyzer in CE-1 Satellite. The software uses the appropriate format to assemble science data package and appropriate command respond mode, realizes the data transferring tasks through the 1553B bus on time, event though the channel bandwidth is under the limited. Also, the memory distribution and management of LOXIA (remote terminal) that fitted the communication with BC(Bus Controller) was introduced. Furthermore, for the spatial application, the security and reliability of software are emphasized. (authors)

Proceedings of the Twenty-First NASA Propagation Experimenters Meeting (NAPEX XXI) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

Science.gov (United States)

Golshan, Nasser (Editor)

1997-01-01

The NASA Propagation Experimenters (NAPEX) meeting is convened each year to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications industry, academia and government who have an interest in space-ground radio wave propagation are invited to NAPEX meetings for discussions and exchange of information. The reports delivered at this meeting by program managers and investigators present recent activities and future plans. This forum provides an opportunity for peer discussion of work in progress, timely dissemination of propagation results, and close interaction with the satellite communications industry.

Using satellite communications for a mobile computer network

Science.gov (United States)

Wyman, Douglas J.

1993-01-01

The topics discussed include the following: patrol car automation, mobile computer network, network requirements, network design overview, MCN mobile network software, MCN hub operation, mobile satellite software, hub satellite software, the benefits of patrol car automation, the benefits of satellite mobile computing, and national law enforcement satellite.

33 CFR 103.310 - Responsibilities of the Area Maritime Security (AMS) Committee.

Science.gov (United States)

2010-07-01

... disseminating appropriate security information to port stakeholders. ... Maritime Security (AMS) Committee. 103.310 Section 103.310 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARITIME SECURITY: AREA MARITIME SECURITY Area Maritime...

Defining a Communications Satellite Policy System for the 21st Century: A Model for a International Legal Framework and A New _Code of Conduct_

Science.gov (United States)

Pelton, Joseph N.

1996-02-01

This paper addresses the changing international communications environment and explores the key elements of a new policy framework for the 21st Century. It addresses the issues related to changing markets, trade considerations, standards, regulatory changes and international institutions and law. The most important aspects will related to new international policy and regulatory frameworks and in particular to a new international code of ethics and behavior in the field of satellite communications. A new communications satellite policy framework requires systematically addressing the following points: • Multi-lateral agreements at the nation state and the operating entity level • Systematic means to access both private and public capital • Meshing ITU regulations with regional and national policy guidelines including • landing rights" and national allocation procedures. • Systematic approach to local partnerships • Resolving the issue of the relative standing of various satellite systems (i.e. GEO, MEO, and LEO systems) • Resolving the rights, duties, and priorities of satellite facility providers versus types of service prviders. Beyond this policy framework and generalized legal infrastructure there is also another need. This is a need that arises from both increased globalism and competitive international markets. This is what might quite simply be called a "code of reasonable conduct:" To provide global and international communications services effectively and well in the 21st Century will require more than meeting minimum international legal requirements. A new "code of conduct" for global satellite communications will thus likely need to address: • Privacy and surveillance • Ethics of transborder data flow • Censorship and moral values • Cultural and linguistic sensitivity • Freedom of the press and respect for journalistic standards As expanding global information and telecommunications systems grow and impact every aspect of modern

On English Teaching in Maritime Colleges

Science.gov (United States)

Shen, Jiang; Wang, Honggui

2011-01-01

According to English level of Chinese ocean sailors at present, we analyze the characteristics and instruction needs of navigation English and point out current English teaching in maritime specialty has many problems. Traditional teaching modes are not suitable for modern maritime needs any longer. So we propose feasible methods and…

Maritime emergency management capabilities in the Arctic

DEFF Research Database (Denmark)

Roud, Ensieh Kheiri Pileh; Borch, Odd Jarl; Jakobsen, Uffe

2016-01-01

Growing maritime commercial activities in the High North increase the possibility of unwanted incidents. The vulnerability related to human safety and environment and a challenging context, call for a strengthening of the maritime preparedness system, and cross-boundary and cross-institutional co......Growing maritime commercial activities in the High North increase the possibility of unwanted incidents. The vulnerability related to human safety and environment and a challenging context, call for a strengthening of the maritime preparedness system, and cross-boundary and cross......-institutional collaboration. In this paper, we look into the different stressors and risk factors of the sea regions in the High North. We elaborate on emergencies where integrated operations such as mass evacuation, oil spill recovery and salvage are needed. Coordination of such operations is a challenging task, where...

Advanced Communication Technology Satellite (ACTS) Very Small Aperture Terminal (VSAT) Network Control Performance

Science.gov (United States)

Coney, T. A.

1996-01-01

This paper discusses the performance of the network control function for the Advanced Communications Technology Satellite (ACTS) very small aperture terminal (VSAT) full mesh network. This includes control of all operational activities such as acquisition, synchronization, timing and rain fade compensation as well as control of all communications activities such as on-demand integrated services (voice, video, and date) connects and disconnects Operations control is provided by an in-band orderwire carried in the baseboard processor (BBP) control burst, the orderwire burst, the reference burst, and the uplink traffic burst. Communication services are provided by demand assigned multiple access (DAMA) protocols. The ACTS implementation of DAMA protocols ensures both on-demand and integrated voice, video and data services. Communications services control is also provided by the in-band orderwire but uses only the reference burst and the uplink traffic burst. The performance of the ACTS network control functions have been successfully tested during on-orbit checkout and in various VSAT networks in day to day operations. This paper discusses the network operations and services control performance.

32 CFR 536.121 - Claims not payable as maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Claims not payable as maritime claims. 536.121... ACCOUNTS CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.121 Claims not payable as maritime claims... (except at (e) and (k)), and 536.46; (b) Are not maritime in nature; (c) Are not in the best interests of...

Evolving earth-based and in-situ satellite network architectures for Mars communications and navigation support

Science.gov (United States)

Hastrup, Rolf; Weinberg, Aaron; McOmber, Robert

1991-09-01

Results of on-going studies to develop navigation/telecommunications network concepts to support future robotic and human missions to Mars are presented. The performance and connectivity improvements provided by the relay network will permit use of simpler, lower performance, and less costly telecom subsystems for the in-situ mission exploration elements. Orbiting relay satellites can serve as effective navigation aids by supporting earth-based tracking as well as providing Mars-centered radiometric data for mission elements approaching, in orbit, or on the surface of Mars. The relay satellite orbits may be selected to optimize navigation aid support and communication coverage for specific mission sets.

Multi-Satellite MIMO Communications at Ku-Band and Above: Investigations on Spatial Multiplexing for Capacity Improvement and Selection Diversity for Interference Mitigation

Directory of Open Access Journals (Sweden)

Liolis Konstantinos P

2007-01-01

Full Text Available This paper investigates the applicability of multiple-input multiple-output (MIMO technology to satellite communications at the Ku-band and above. After introducing the possible diversity sources to form a MIMO matrix channel in a satellite environment, particular emphasis is put on satellite diversity. Two specific different topics from the field of MIMO technology applications to satellite communications at these frequencies are further analyzed: (i capacity improvement achieved by MIMO spatial multiplexing systems and (ii interference mitigation achieved by MIMO diversity systems employing receive antenna selection. In the first case, a single-user capacity analysis of a satellite MIMO spatial multiplexing system is presented and a useful analytical closed form expression is derived for the outage capacity achieved. In the second case, a satellite MIMO diversity system with receive antenna selection is considered, adjacent satellite cochannel interference on its forward link is studied and an analytical model predicting the interference mitigation achieved is presented. In both cases, an appropriate physical MIMO channel model is assumed which takes into account the propagation phenomena related to the frequencies of interest, such as clear line-of-sight operation, high antenna directivity, the effect of rain fading, and the slant path lengths difference. Useful numerical results obtained through the analytical expressions derived are presented to compare the performance of multi-satellite MIMO systems to relevant single-input single-output (SISO ones.

33 CFR 103.305 - Composition of an Area Maritime Security (AMS) Committee.

Science.gov (United States)

2010-07-01

... port stakeholders having a special competence in maritime security; and (7) Port stakeholders affected... Security (AMS) Committee. 103.305 Section 103.305 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARITIME SECURITY: AREA MARITIME SECURITY Area Maritime...

Current Issues in Maritime Health

DEFF Research Database (Denmark)

Wagtmann, Maria Anne

2008-01-01

 In the early part of 2008, Maria Anne Wagtmann had the opportunity to interview the former president of the International Maritime Health Association, Dr. Tim Carter, in London about a number of current maritime health issues. In this interview, Dr. Tim Carter, who is cur­rently employed...... as the Chief Medical Advisor for the British government's Department for Transport, gives his personal - and thus non-official - opinions on these issues....

Maritime Violence : Implications to Malaysia

OpenAIRE

Zubir, Nurulizwan Ahmad

2012-01-01

Abstract Maritime Piracy has been a serious threat to the international community especially in the SoutheastAsia region. This threat has caused tremendous implications towards the world economy, environment,political stability of the nations involved because 45% of the shipping company passes through theSoutheast Asia. The worrying fact is that these attacks were committed by terrorists as well as traditionalmaritime pirates. This paper examines on the implications of maritime crime in M...

Det Maritime Hus

DEFF Research Database (Denmark)

Albrechtsen, Thomas Rohde Skovdal

2017-01-01

Denne rapport er en slutevaluering af udviklingsprojektet Det Maritime Hus, og består af en analyse og diskussion af en spørgeskemaundersøgelse foretaget i perioden efterår 2014 til forår 2017. Evalueringen besvarer følgende tre spørgsmål og målsætninger med projektet: 1. På hvilke måder formåede...... lærere undervisningsforløbet som brugbart i forhold til egen undervisning? Konklusionen på evalueringen er, at Det Maritime Hus har formået at understøtte de deltagende elevers interesse og læring inden for science-området gennem de designede undervisningsforløb, som er blevet udbudt og gennemført i...

Considerations of digital phase modulation for narrowband satellite mobile communication

Science.gov (United States)

Grythe, Knut

1990-01-01

The Inmarsat-M system for mobile satellite communication is specified as a frequency division multiple access (FDMA) system, applying Offset Quadrature Phase Shift Keying (QPSK) for transmitting 8 kbit/sec in 10 kHz user channel bandwidth. We consider Digital Phase Modulation (DPM) as an alternative modulation format for INMARSAT-M. DPM is similar to Continuous Phase Modulation (CPM) except that DPM has a finite memory in the premodular filter with a continuous varying modulation index. It is shown that DPM with 64 states in the VA obtains a lower bit error rate (BER). Results for a 5 kHz system, with the same 8 kbit/sec transmitted bitstream, is also presented.

32 CFR 536.124 - Settlement authority for maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Settlement authority for maritime claims. 536.124 Section 536.124 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY CLAIMS AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.124 Settlement authority for maritime...

33 CFR 105.230 - Maritime Security (MARSEC) Level coordination and implementation.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maritime Security (MARSEC) Level..., DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARITIME SECURITY: FACILITIES Facility Security Requirements § 105.230 Maritime Security (MARSEC) Level coordination and implementation. (a) The facility owner...

Global-scale Observations of the Limb and Disk (GOLD) Mission: Science from Geostationary Orbit on-board a Commercial Communications Satellite

Science.gov (United States)

Eastes, R.; Deaver, T.; Krywonos, A.; Lankton, M. R.; McClintock, W. E.; Pang, R.

2011-12-01

Geostationary orbits are ideal for many science investigations of the Earth system on global scales. These orbits allow continuous observations of the same geographic region, enabling spatial and temporal changes to be distinguished and eliminating the ambiguity inherent to observations from low Earth orbit (LEO). Just as observations from geostationary orbit have revolutionized our understanding of changes in the troposphere, they will dramatically improve our understanding of the space environment at higher altitudes. However, geostationary orbits are infrequently used for science missions because of high costs. Geostationary satellites are large, typically weighing tons. Consequently, devoting an entire satellite to a science mission requires a large financial commitment, both for the spacecraft itself and for sufficient science instrumentation to justify a dedicated spacecraft. Furthermore, the small number of geostationary satellites produced for scientific missions increases the costs of each satellite. For these reasons, it is attractive to consider flying scientific instruments on satellites operated by commercial companies, some of whom have fleets of ~40 satellites. However, scientists' lack of understanding of the capabilities of commercial spacecraft as well as commercial companies' concerns about risks to their primary mission have impeded the cooperation necessary for the shared use of a spacecraft. Working with a commercial partner, the GOLD mission has successfully overcome these issues. Our experience indicates that there are numerous benefits to flying on commercial communications satellites (e.g., it is possible to downlink large amounts of data) and the costs are low if the experimental requirements adequately match the capabilities and available resources of the host spacecraft. Consequently, affordable access to geostationary orbit aboard a communications satellite now appears possible for science payloads.

The Irish Maritime Transport Economist Volume 3

OpenAIRE

Office, Irish Maritime Development

2006-01-01

The Irish Maritime Development Office (IMDO) of the Marine Institute publishes the Irish Maritime Transport Economist each year to provide a descriptive statistical analysis of the Irish ports and shipping services sector, as well as the many factors influencing its performance.

The Irish Maritime Transport Economist Volume 4

OpenAIRE

Office, Irish Maritime Development

2007-01-01

The Irish Maritime Development Office (IMDO) of the Marine Institute publishes the Irish Maritime Transport Economist each year to provide a descriptive statistical analysis of the Irish ports and shipping services sector, as well as the many factors influencing its performance.

33 CFR 104.240 - Maritime Security (MARSEC) Level coordination and implementation.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maritime Security (MARSEC) Level..., DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARITIME SECURITY: VESSELS Vessel Security Requirements § 104.240 Maritime Security (MARSEC) Level coordination and implementation. (a) The vessel owner or...

The Maritime Cultural Landscape of Northern Patagonia

Science.gov (United States)

Lira, Nicolás

2017-12-01

This article is a contribution to the study of the indigenous navigation and its boats in the region of northern Patagonia. This article also aims to contribute to the understanding of indigenous navigation practices and technologies and their origins from prehistoric times to the mid-twentieth century. It presents and discusses the concept of Westerdahl's Maritime Cultural Landscape in relation to other landscape concepts. This model is applied to northern Patagonia in order to discuss if it is possible to speak of a true maritime culture in the region. For this purpose, archaeological, historical and ethnographic data are presented in an integrative and innovative methodology for the discipline. Finally, the Maritime Cultural Landscape model will allow the integration of aquatic and terrestrial landscapes as routes traveled by native inhabitants of northern Patagonia and southern Chile, and propose an important and diversified maritime, river and lake tradition.

System аnalysis concession maritime trade ports

Directory of Open Access Journals (Sweden)

Y.V. Shmatock

2015-03-01

Full Text Available The article proves the significance of maritime commercial ports as strategic for the country. The urgency of port concessions to improve transport infrastructure. The definition of ports in terms of system analysis and determination of management port. Outlined the sequence of system analysis concessions maritime trade ports in the table. Selection of qualified managers is based on the concession tender under prescribed conditions. These criteria should be considered when determining the concessionaire. These stages of the concession tender. Meeting the needs of the economy, international trade, public inquiries into transportation of goods is not possible without the efficient operation of maritime trade ports. Only complex technological modernization of maritime trade ports will enable them to take leadership positions. Tree depicted objectives effectively manage commercial sea port. Therefore, initiation of concessions needs to implement measures to achieve the talented and skillful result.

Advanced Communication Technology Satellite (ACTS) multibeam antenna analysis and experiment

Science.gov (United States)

Acosta, Roberto J.; Lagin, Alan R.; Larko, Jeffrey M.; Narvaez, Adabelle

1992-01-01

One of the most important aspects of a satellite communication system design is the accurate estimation of antenna performance degradation. Pointing error, end coverage gain, peak gain degradation, etc. are the main concerns. The thermal or dynamic distortions of a reflector antenna structural system can affect the far-field antenna power distribution in a least four ways. (1) The antenna gain is reduced; (2) the main lobe of the antenna can be mispointed thus shifting the destination of the delivered power away from the desired locations; (3) the main lobe of the antenna pattern can be broadened, thus spreading the RF power over a larger area than desired; and (4) the antenna pattern sidelobes can increase, thus increasing the chances of interference among adjacent beams of multiple beam antenna system or with antenna beams of other satellites. The in-house developed NASA Lewis Research Center thermal/structural/RF analysis program was designed to accurately simulate the ACTS in-orbit thermal environment and predict the RF antenna performance. The program combines well establish computer programs (TRASYS, SINDA and NASTAN) with a dual reflector-physical optics RF analysis program. The ACTS multibeam antenna configuration is analyzed and several thermal cases are presented and compared with measurements (pre-flight).

Green Maritime Logistics

DEFF Research Database (Denmark)

Psaraftis, Harilaos N.

2014-01-01

Typical problems in maritime logistics include, among others, optimal ship speed, ship routing and scheduling, fleet deployment, fleet size and mix, weather routing, intermodal network design, modal split, transshipment, queuing at ports, terminal management, berth allocation, and total supply...... chain management. The traditional analysis of these problems has been in terms of cost- benefit and other optimization criteria from the point of view of the logistics provider, carrier, shipper, or other end-user. Such traditional analysis by and large either ignores environmental issues, or considers...... them of secondary importance. Green maritime logistics tries to bring the environmental dimension into the problem, and specifically the dimension of emissions reduction, by analyzing various trade-offs and exploring ‘win-win’ solutions. This talk takes a look at the trade-offs that are at stake...

Plan of Time Management of Satellite Positioning System using Quasi-zenith Satellite

Science.gov (United States)

Takahashi, Yasuhiro; Fujieda, Miho; Amagai, Jun; Yokota, Shoichiro; Kimura, Kazuhiro; Ito, Hiroyuki; Hama, Shin'ichi; Morikawa, Takao; Kawano, Isao; Kogure, Satoshi

The Quasi-Zenith satellites System (QZSS) is developed as an integrated satellite service system of communication, broadcasting and positioning for mobile users in specified regions of Japan from high elevation angle. Purposes of the satellite positioning system using Quasi-Zenith satellite (QZS) are to complement and augment the GPS. The national institutes concerned have been developing the positioning system using QZS since 2003 and will carry out experiments and researches in three years after the launch. In this system, National Institute of Information and Communications Technology (NICT) is mainly in charge of timing system for the satellite positioning system using QZS, such as onboard hydrogen maser atomic clock and precise time management system of the QZSS. We started to develop the engineering model of the time management system for the QZSS. The time management system for the QZSS will be used to compare time differences between QZS and earth station as well as to compare between three onboard atomic clocks. This paper introduces time management of satellite positioning system using the QZSS.

INTEGRITY ANALYSIS OF REAL-TIME PPP TECHNIQUE WITH IGS-RTS SERVICE FOR MARITIME NAVIGATION

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M. El-Diasty

2017-10-01

Full Text Available Open sea and inland waterways are the most widely used mode for transporting goods worldwide. It is the International Maritime Organization (IMO that defines the requirements for position fixing equipment for a worldwide radio-navigation system, in terms of accuracy, integrity, continuity, availability and coverage for the various phases of navigation. Satellite positioning systems can contribute to meet these requirements, as well as optimize marine transportation. Marine navigation usually consists of three major phases identified as Ocean/Coastal/Port approach/Inland waterway, in port navigation and automatic docking with alert limit ranges from 25 m to 0.25 m. GPS positioning is widely used for many applications and is currently recognized by IMO for a future maritime navigation. With the advancement in autonomous GPS positioning techniques such as Precise Point Positioning (PPP and with the advent of new real-time GNSS correction services such as IGS-Real-Time-Service (RTS, it is necessary to investigate the integrity of the PPP-based positioning technique along with IGS-RTS service in terms of availability and reliability for safe navigation in maritime application. This paper monitors the integrity of an autonomous real-time PPP-based GPS positioning system using the IGS real-time service (RTS for maritime applications that require minimum availability of integrity of 99.8 % to fulfil the IMO integrity standards. To examine the integrity of the real-time IGS-RTS PPP-based technique for maritime applications, kinematic data from a dual frequency GPS receiver is collected onboard a vessel and investigated with the real-time IGS-RTS PPP-based GPS positioning technique. It is shown that the availability of integrity of the real-time IGS-RTS PPP-based GPS solution is 100 % for all navigation phases and therefore fulfil the IMO integrity standards (99.8 % availability immediately (after 1 second, after 2 minutes and after 42 minutes

Integrity Analysis of Real-Time Ppp Technique with Igs-Rts Service for Maritime Navigation

Science.gov (United States)

El-Diasty, M.

2017-10-01

Open sea and inland waterways are the most widely used mode for transporting goods worldwide. It is the International Maritime Organization (IMO) that defines the requirements for position fixing equipment for a worldwide radio-navigation system, in terms of accuracy, integrity, continuity, availability and coverage for the various phases of navigation. Satellite positioning systems can contribute to meet these requirements, as well as optimize marine transportation. Marine navigation usually consists of three major phases identified as Ocean/Coastal/Port approach/Inland waterway, in port navigation and automatic docking with alert limit ranges from 25 m to 0.25 m. GPS positioning is widely used for many applications and is currently recognized by IMO for a future maritime navigation. With the advancement in autonomous GPS positioning techniques such as Precise Point Positioning (PPP) and with the advent of new real-time GNSS correction services such as IGS-Real-Time-Service (RTS), it is necessary to investigate the integrity of the PPP-based positioning technique along with IGS-RTS service in terms of availability and reliability for safe navigation in maritime application. This paper monitors the integrity of an autonomous real-time PPP-based GPS positioning system using the IGS real-time service (RTS) for maritime applications that require minimum availability of integrity of 99.8 % to fulfil the IMO integrity standards. To examine the integrity of the real-time IGS-RTS PPP-based technique for maritime applications, kinematic data from a dual frequency GPS receiver is collected onboard a vessel and investigated with the real-time IGS-RTS PPP-based GPS positioning technique. It is shown that the availability of integrity of the real-time IGS-RTS PPP-based GPS solution is 100 % for all navigation phases and therefore fulfil the IMO integrity standards (99.8 % availability) immediately (after 1 second), after 2 minutes and after 42 minutes of convergence

Maritime transport in the Gulf of Bothnia 2030.

Science.gov (United States)

Pekkarinen, Annukka; Repka, Sari

2014-10-01

Scenarios for shipping traffic in the Gulf of Bothnia (GoB) by 2030 are described in order to identify the main factors that should be taken into account when preparing a Maritime Spatial Plan (MSP) for the area. The application of future research methodology to planning of marine areas was also assessed. The methods include applying existing large scale quantitative scenarios for maritime traffic in the GoB and using real-time Delphi in which an expert group discussed different factors contributing to future maritime traffic in the GoB to find out the probability and significance of the factors having an impact on maritime traffic. MSP was tested on transnational scale in the Bothnian sea area as a pilot project.

47 CFR 25.143 - Licensing provisions for the 1.6/2.4 GHz mobile-satellite service and 2 GHz mobile-satellite...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing provisions for the 1.6/2.4 GHz mobile-satellite service and 2 GHz mobile-satellite service. 25.143 Section 25.143 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...

Telelibrary: Library Services via Satellite.

Science.gov (United States)

Liu, Rosa

1979-01-01

Investigates the provision of library services via satellite, explains briefly the operation and advantages of communication satellites, and discusses the various telecommunications equipment and services which, when coupled with satellite transmission, will enhance library activities. Demand trend projections for telecommunications services…

Cockpit weather graphics using mobile satellite communications

Science.gov (United States)

Seth, Shashi

1993-01-01

Many new companies are pushing state-of-the-art technology to bring a revolution in the cockpits of General Aviation (GA) aircraft. The vision, according to Dr. Bruce Holmes - the Assistant Director for Aeronautics at National Aeronautics and Space Administration's (NASA) Langley Research Center, is to provide such an advanced flight control system that the motor and cognitive skills you use to drive a car would be very similar to the ones you would use to fly an airplane. We at ViGYAN, Inc., are currently developing a system called the Pilot Weather Advisor (PWxA), which would be a part of such an advanced technology flight management system. The PWxA provides graphical depictions of weather information in the cockpit of aircraft in near real-time, through the use of broadcast satellite communications. The purpose of this system is to improve the safety and utility of GA aircraft operations. Considerable effort is being extended for research in the design of graphical weather systems, notably the works of Scanlon and Dash. The concept of providing pilots with graphical depictions of weather conditions, overlaid on geographical and navigational maps, is extremely powerful.

Toward the Public Dividend: A Report on Satellite Telecommunications and the Public Interest Satellite Association.

Science.gov (United States)

McGraw, Walter

This report points out that the communications satellite appears to be on its way to becoming one of the most dominant and controlling technologies of our time, and this requires that a new evaluation be made of our entire communications process. The first section of the report discusses many aspects of the history of satellites, including the…

The effectiveness of maritime safety policy instruments from the Finnish maritime experts’ point of view – case Gulf of Finland and prevention of an oil accident

Directory of Open Access Journals (Sweden)

Jouni Lappalainen

2013-09-01

Full Text Available Sea accidents are aimed to be prevented with an extensive amount of maritime safety regulation. The purpose of this paper is to present the findings of a questionnaire study that was targeted at Finnish maritime experts and addressed the question: how to prevent an oil accident in the Gulf of Finland. This study also includes a literature study about the problems of the current maritime safety regime. The findings of the questionnaire study are compared to the findings of the literature study. The questionnaire study showed that many kinds of policies have improved maritime safety, and they are needed to ensure maritime safety. For instance, ship construction, fairway maintenance, nautical charts and rules of the road at sea can be considered the cornerstones of maritime safety. However, the results ranked voluntary activities of companies as the most effective way to improve maritime safety in the future. Self-regulative approaches could solve some problems connected to more traditional policy-making.

Study of Education Satellite Communication Demonstration. Third Quarterly Progress Report. Report of Activities and Accomplishments January 11, 1975 to April 10, 1975.

Science.gov (United States)

Syracuse Univ. Research Corp., NY. Educational Policy Research Center.

A report on the Education Satellite Communication Demonstration (ESCD) describes activities of the evaluators during the first quarter of 1975, including staff trips and site visits and activities of various staff members. A calendar of future events in satellites, telecommunications, and education is included, with revision on dates and new…

Particle Filtering Equalization Method for a Satellite Communication Channel

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Amblard Pierre-Olivier

2004-01-01

Full Text Available We propose the use of particle filtering techniques and Monte Carlo methods to tackle the in-line and blind equalization of a satellite communication channel. The main difficulties encountered are the nonlinear distortions caused by the amplifier stage in the satellite. Several processing methods manage to take into account these nonlinearities but they require the knowledge of a training input sequence for updating the equalizer parameters. Blind equalization methods also exist but they require a Volterra modelization of the system which is not suited for equalization purpose for the present model. The aim of the method proposed in the paper is also to blindly restore the emitted message. To reach this goal, a Bayesian point of view is adopted. Prior knowledge of the emitted symbols and of the nonlinear amplification model, as well as the information available from the received signal, is jointly used by considering the posterior distribution of the input sequence. Such a probability distribution is very difficult to study and thus motivates the implementation of Monte Carlo simulation methods. The presentation of the equalization method is cut into two parts. The first part solves the problem for a simplified model, focusing on the nonlinearities of the model. The second part deals with the complete model, using sampling approaches previously developed. The algorithms are illustrated and their performance is evaluated using bit error rate versus signal-to-noise ratio curves.

COMPARATIVE ANALYSIS OF POLISH AND CROATIAN MARITIME POLICY IN THE CONTEXT OF THE INTEGRATED MARITIME POLICY OF THE EUROPEAN UNION

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Katarzyna Skrzeszewska

2016-12-01

Full Text Available Traditional activities based on sea resources (maritime transport, shipyards, fishery always played the key role in increasing production possibilities of the economies with the access to the sea. The development of technique and technology distinctly contributed to broadening the horizons and diversification of activities based on exploitation of maritime basins. Despite the positive results connected with greater and more intense exploration of seas resources, there also appeared the negative effects. First and foremost, they are connected with degradation of the natural environment and growing conflicts of interests of different groups of the basins users. The issue of split entitlement to use seas resources was brought to the world forum in 1982 by enacting the United Nations Convention on the Law of the Sea (UNCLOS. The European Commission, having contucted consultations on a large scale, accepted the Integrated Maritime Policy of the European Union (IMP EU. It was based on the assumption, that all maritime activities are interconnected and that is why they should be performed in a coordinated manner to achive the established goals. The Integrated Maritime Policy created the framework, in which the member states were to find appropiate solutions to their economy specificity, inter alia – the maritime economy. In the paper, the results of the research of maritime policies of two countries - Poland and Croatia are presented. The goal of the research is to check how far the policies of these two countries are coherent with each other and with the assumptions of the IMP. In the research the deductive method was used - it was based at conclusions from the comparative analysis. The surveys were conducted on the basis of the EU, Polish and Croatian strategic documents.

Maritime Laser Scanning as the Source for Spatial Data

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Szulwic Jakub

2015-12-01

Full Text Available The rapid development of scanning technology, especially mobile scanning, gives the possibility to collect spatial data coming from maritime measurement platforms and autonomous manned or unmanned vehicles. Presented solution is derived from the mobile scanning. However we should keep in mind that the specificity of laser scanning at sea and processing collected data should be in the form acceptable in Geographical Information Systems, especially typical for the maritime needs. At the same time we should be aware that data coming from maritime mobile scanning constitutes a new approach to the describing of maritime environment and brings a new perspective that is completely different than air and terrestrial scanning.

Characteristic and factors of competitive maritime industry clusters in Indonesia

Science.gov (United States)

Marlyana, N.; Tontowi, A. E.; Yuniarto, H. A.

2017-12-01

Indonesia is situated in the strategic position between two oceans therefore is identified as a maritime state. The fact opens big opportunity to build a competitive maritime industry. However, potential factors to boost the competitive maritime industry still need to be explored. The objective of this paper is then to determine the main characteristics and potential factors of competitive maritime industry cluster. Qualitative analysis based on literature review has been carried out in two aspects. First, benchmarking analysis conducted to distinguish the most relevant factors of maritime clusters in several countries in Europe (Norway, Spain, South West of England) and Asia (China, South Korea, Malaysia). Seven key dimensions are used for this benchmarking. Secondly, the competitiveness of maritime clusters in Indonesia was diagnosed through a reconceptualization of Porter’s Diamond model. There were four interlinked of advanced factors in and between companies within clusters, which can be influenced in a proactive way by government.

Risk assessment in maritime transportation

International Nuclear Information System (INIS)

Soares, C. Guedes; Teixeira, A.P.

2001-01-01

A review is presented of different approaches to quantify the risk in maritime transportation. The discussion of several accident statistics provides a global assessment of the risk levels and its differentiation in ship types and main types of ship losses. Early studies in the probability of ship loss by foundering and capsizing are reviewed. The approaches used to assess the risk of structural design are addressed. Finally a brief account is given of recent development of using formal safety assessments to support decision making on legislation applicable internationally to maritime transportation

Izviđanje satelitskih komunikacija u funkciji savremenih operacija / Reconnaissance of satellite communications in contemporary operations

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Slaviša Đukanović

2004-05-01

Full Text Available Raspoloživi vojni resursi u bilo kojoj kategoriji nisu kritični u mirnodopskom periodu, jer se dimenzionišu za ratno naprezanje određenog nivoa. Međutim, u uslovima izvođenja borbenih dejstava postoje ekstremi u zahtevima za angažovanjem, koje sistemi ne mogu da izdrže. Takav slučaj je kod satelitskih komunikacija. U radu su prezentovane taktičko-tehničke i dinamičke osobine komercijalnih (INMARSAT, INTELSAT, IRIDIJUM.. i vojnih (DSCS, FLEET-SATCOM, NATO, SKYNET.. satelitskih sistema, koje su bitne za uspešno vođenje elektronskog rata. Takođe, dat je pregled raspoloživih korisničkih servisa savremenih satelitskih sistema (Internet provajding video-konferencije, prenos multimedija uživo, fax, e-mail, voice. Nova generacija širokopojasnih satelita, koja se pušta u rad tokom ove godine omogućiće globalni roming navedenih servisa INMARSAT satelitskom sistemu koji se sve češće koristi u vojne svrhe. U perspektivi je da se usluge koje pružaju satelitski sistemi (komunikacioni, navigacioni, izviđački meteorološki.. stave na raspolaganje nižim taktičkim jedinicama vazduhoplovima, pa čak i svakom vojniku ponaosob. Poznavanje satelitskih sistema potencijalnog agresora pruža mogućnost da se odrede ranjive tačke samog sistema sa aspekta izviđanja i ometanja. / Available military resources in any category are not critical in peace since they are tailored for military use under extreme conditions. However, some systems such as satellite communications, cannot meet extreme requirements during combat actions. The paper presents tactical and technical specifications and dynamic characteristics of commercial (INMARSAT. INTELSAT, IRIDIJUM,.. and military (DSCS, FLEET-SATCOM, NATO, SKYNET,.. satellite systems which are important for electronic warfare. The paper also gives available user services of contemporary satellite systems (Internet providing, videoconferences, live multi-media, fax, e-mail, voice. A new generation of

Effect of Policy Analysis on Indonesia’s Maritime Cluster Development Using System Dynamics Modeling

Science.gov (United States)

Nursyamsi, A.; Moeis, A. O.; Komarudin

2018-03-01

As an archipelago with two third of its territory consist of water, Indonesia should address more attention to its maritime industry development. One of the catalyst to fasten the maritime industry growth is by developing a maritime cluster. The purpose of this research is to gain understanding of the effect if Indonesia implement maritime cluster policy to the growth of maritime economic and its role to enhance the maritime cluster performance, hence enhancing Indonesia’s maritime industry as well. The result of the constructed system dynamic model simulation shows that with the effect of maritime cluster, the growth of employment rate and maritime economic is much bigger that the business as usual case exponentially. The result implies that the government should act fast to form a legitimate cluster maritime organizer institution so that there will be a synergize, sustainable, and positive maritime cluster environment that will benefit the performance of Indonesia’s maritime industry.

32 CFR 536.123 - Limitation of liability for maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Limitation of liability for maritime claims. 536... AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.123 Limitation of liability for maritime claims. For admiralty claims arising within the United States under the provisions of the...

32 CFR 536.122 - Limitation of settlement of maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Limitation of settlement of maritime claims. 536... AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Maritime Claims § 536.122 Limitation of settlement of maritime claims. (a) Within the United States the period of completing an administrative settlement under...

Experimental test for receiving X-Band data LAPAN-A3 Satellite with 5.4m antenna diameter

Science.gov (United States)

Dwi Harsono, Sonny; Hasbi, Wahyudi

2018-05-01

LAPAN-A3 / LAPAN-IPB Satellite launched on June 22, 2016 (03:56 UTC) as an experimental micro-satellite for remote sensing and monitoring of maritime traffic. The Satellite was launched as a secondary payload on ISRO Cartosat-2C as its main payload, the launch carried out at SDSC (Satish Dhawan Space Centre) in India using PSLV-C34 rocket launcher. The Satellite was in orbit polar sun-synchronous with a height of 505 km above sea level. It has an inclination angle of 97 degrees and heavy satellite 115 kg, with this orbit, the satellite will pass through Ground station 4 times (2 times during the day and two times at night) with a duration of the track at the time of the pass about 10-15 minutes. The Satellite payload carried 4 bands Line Scan Cameras and Digital Imager (SpaceCam). For main mission is the earth observation for food vegetables And as additional mission is carrying AIS (Automatic Identification System) receiver to monitor maritime traffic in the region of the poles, then Star Sensor made by LAPAN for qualifying room, then for scientific contained magnetometer sensor for monitoring the Earth's Magnetic field. The purpose of this scientific paper is to test the reception of data payloads of the LAPAN-A3 satellite on X-Band frequency of 8.2 GHz using a 5.4 M solid antenna Ground Stations LAPAN in Pare-Pare. The purpose of this experiment will tell us with 5.4 meter of diameter solid antenna is capable or not enough for HDRM receiver to lock a signal and produce the data output, and how this result if compare with 11 meter of diameter antenna in Splitzberg Groundstation in Norway.

Risk of the Maritime Supply Chain System Based on Interpretative Structural Model

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Jiang He

2017-11-01

Full Text Available Marine transportation is the most important transport mode of in the international trade, but the maritime supply chain is facing with many risks. At present, most of the researches on the risk of the maritime supply chain focus on the risk identification and risk management, and barely carry on the quantitative analysis of the logical structure of each influencing factor. This paper uses the interpretative structure model to analysis the maritime supply chain risk system. On the basis of comprehensive literature analysis and expert opinion, this paper puts forward 16 factors of maritime supply chain risk system. Using the interpretative structure model to construct maritime supply chain risk system, and then optimize the model. The model analyzes the structure of the maritime supply chain risk system and its forming process, and provides a scientific basis for the controlling the maritime supply chain risk, and puts forward some corresponding suggestions for the prevention and control the maritime supply chain risk.

Indonesian Sea Power and Regional Maritime Security Challenges

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Marsetio Marsetio

2017-07-01

Full Text Available The main objective of this paper is to examine the regional maritime security challenges facing Indonesia. As it is known that entering to the 21st century has come a new term in regional architecture in the Asia-Pacific region, namely the Indo-Pacific region. This region consists of the Indian Ocean and Pacific. Both of these areas became more interconnected than in the previous period. These two regions became a single, significant system in the global order. Key players in the Indo-Pacific region are China, India and the United States. Of course, their actions have created new challenges in maritime security. These challenges include maritime disputes, pirates, and maritime power competition. The dispute in the South China Sea has spawned a security problem in the Asia Pacific region that Indonesia must face in the future.

Human Factors and Safety Culture in Maritime Safety (revised

Directory of Open Access Journals (Sweden)

Heinz Peter Berg

2013-09-01

Full Text Available As in every industry at risk, the human and organizational factors constitute the main stakes for maritime safety. Furthermore, several events at sea have been used to develop appropriate risk models. The investigation on maritime accidents is, nowadays, a very important tool to identify the problems related to human factor and can support accident prevention and the improvement of maritime safety. Part of this investigation should in future also be near misses. Operation of ships is full of regulations, instructions and guidelines also addressing human factors and safety culture to enhance safety. However, even though the roots of a safety culture have been established, there are still serious barriers to the breakthrough of the safety management. One of the most common deficiencies in the case of maritime transport is the respective monitoring and documentation usually lacking of adequacy and excellence. Nonetheless, the maritime area can be exemplified from other industries where activities are ongoing to foster and enhance safety culture.

Maritime Interdiction Operations Small Craft Detection

International Nuclear Information System (INIS)

Dougan, A.D.; Trombino, D.; Dunlop, W.; Bordetsky, A.

2010-01-01

The Naval Postgraduate School has been conducting Tactical Network Topology (TNT) Maritime Interdiction Operations (MIO) experiments with Lawrence Livermore National Laboratory (LLNL) since early in 2005. In this work, we are investigating cutting edge technology to evaluate use of networks, advanced sensors and collaborative technology for globally-supported maritime interdiction operations. Some examples of our research include communications in harsh environments, between moving ships at sea; small boat drive-by radiation detection; network-centric collaboration with global partners; situational awareness; prototype sensors and biometric instruments. Since 2006, we have studied the concept of using a small vessel with fixed radiation sensors to do initial searches for illicit radioactive materials. In our work, we continue to evaluate concepts of operation for small boat monitoring. For example, in San Francisco Bay we established a simulated choke point using two RHIBs. Each RHIB had a large sodium iodide radiation sensor on board, mounted on the side nearest to the passing potential target boats. Once detections were made, notification over the network prompted a chase RHIB also equipped with a radiation sensor to further investigate the potential target. We have also used an unmanned surface vessel (USV) carrying a radiation sensor to perform the initial discovery. The USV was controlled remotely and to drive by boats in different configurations. The potential target vessels were arranged in a line, as a choke point and randomly spaced in the water. Search plans were problematic when weather, waves and drift complicated the ability to stay in one place. A further challenge is to both detect and identify the radioactive materials during the drive-by. Our radiation detection system, ARAM, Adaptable Radiation Area Monitor, is able to detect, alarm and quickly identify plausible radionuclides in real time. We have performed a number of experiments to better

46 CFR 1.01-15 - Organization; Districts; National Maritime Center.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Organization; Districts; National Maritime Center. 1.01... General Flow of Functions § 1.01-15 Organization; Districts; National Maritime Center. (a) To assist the... navigation, vessel inspection and seaman laws in general. (c) The Commanding Officer of the National Maritime...

Introduction to "Binding Maritime China: Control, Evasion, and Interloping"

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Eugenio Menegon

2017-12-01

Full Text Available Maritime Asia is a confusing morass of contested sovereignties and geopolitical rivalries. Yet the seaways of Asia have, in their history, also fostered cultural exchange and economic integration. The liminal maritime zone surrounding China remains a paradox between seas and ports teeming with legal and illegal exchange and governmental policies attempting to monopolize and restrict that exchange. Vast and fluid, maritime China has long hindered state control and fostered connections determined as much by bottom-up economic and cultural logic as by top-down official impositions. This issue of Cross-Currents proposes to reexamine the rich history of maritime China and adjacent areas by tracing the interactions of the three initiatives of control, evasion, and interloping. This special issue stems from a conference the guest editors organized in Boston in 2015, with support from Boston University, Brandeis University, Northeastern University, and the Taiwan Ministry of Education. We invited a distinguished group of scholars to explore the many facets of maritime China’s history. Our key postulation was that state control, evasion from that control, and interloping within the interstices of China’s maritime world literally bound an array of actors and locales for distinct but interrelated goals, from the early modern era to the modern era. This concept is encapsulated in the title of the current issue, “Binding Maritime China.” What “creates” and gives coherence to the concept of maritime China as a social, economic, political, and geographic space is, to a large extent, how human actors (Chinese and Western merchants and businessmen, navy officers, bureaucrats, fishermen, pirates, missionaries, and so on productively interacted or experienced conflicts and resisted one another’s control. They did so across oceanic and coastal spaces, administrative boundaries, class lines, bureaucratic institutions, commercial organizations, and