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17th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2004

作者： Kim, Jeonghan Park, Byungwoon Kee, Changdon Cleveland, Allen Parsons, Michael Wolfe, David Seoul National University Korea Republic of USCG Command and Control Engineering Center United States School of Mechanical and Aerospace Engineering Seoul National University Korea Republic of CNS ATM

The SNUR-2000 v. 2.2 consists of several types of compact RTK-GPS messages whose main components are pseudorange and carrier phase corrections. Using these messages, we can carry out precise RTK-GPS positioning using low-rate data-link. In this paper, we analyze the effect of latency on RTK-GPS positioning error and determine minimum baud-rate of data-link for compact correction messages applied to commercial GPS receivers. We also evaluate the performance of the SNUR-2000 by applying converted correction messages to commercial GPS receivers. Commercial GPS receivers can identify their own proprietary RTK-GPS messages, but not the correction messages of the SNUR-2000 v. 2.2. In order to make RTK-GPS receivers identify the SNUR-2000 messages, we converted the compact correction data to proprietary RTK-GPS data which commercial GPS receivers can identify. For this purpose, we converted compact correction messages to CMR(Compact Measurement Records), which is one of the widely-known RTK-GPS data format. The RTK-GPS receivers decode the converted messages, estimate DD integer ambiguities, then compute RTK-GPS position internally. Test results show that the converted compact correction messages of the SNUR-2000 make it possible to resolve integer ambiguities and to compute precise RTK-GPS position autonomously without performance degradation (Initial test results have been demonstrated in the plenary meeting of the RTCM SC-104 version 3 working group).

关键词： Signal receivers

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Reducing navigation and timing risks in the maritime domain environment

Reducing navigation and timing risks in the maritime domain ...

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Proceedings of the 61st Annual Meeting of The Institute of Navigation

作者： Weeks Jr., K. Peterson, Ben Ryan, Joseph F. Gunther, G.T. USCG United States Coast Guard Command Control Engineering Center Peterson Integrated Geopositioning Skip 'R LLC Booz Allen Hamilton United States Coast Guard ION International Organization of Masters

The Coast Guard is the Department of Homeland Security's lead agency for Maritime Domain Awareness (MDA). To provide for safe, secure and efficient passages through coastal areas and safe approach and entrance into harbors, backup systems to GPS navigation and timing must be integrated into critical command and control, navigation and surveillance systems. This has been reinforced by recent changes to the Presidential policy regarding spaced-based position, navigation and timing application for U.S. national and homeland security, civil, scientific, and commercial purposes. To meet MDA and the strict Coast Guard Electronic Charting and Integrated Navigation System (ECINS) requirements, we will present backup options for integration into maritime and coastal navigation, command and control and surveillance systems.

关键词： Navigation

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engineering the all-weather antenna tuning unit for NDGPS applications

Engineering the all-weather antenna tuning unit for NDGPS ap...

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18th International Technical Meeting of the Satellite Division of The Institute of Navigation, ION GNSS 2005

作者： Treib, Chris A. Gingras, Paul K. Parsons, Michael W. Wolfe, David B. United States Coast Guard Command and Control Engineering Center USCG Command and Control Engineering Center Portsmouth VA C2CEN US Coast Guard's Primary Engineering Facility for Land-based Navigation Systems for Maritime Differential GPS Technical Committee 80 Working Group 4A for GNSS and DGNSS Receiver Standards Radio Navigation Committee Institute of Navigation Council

The U. S. Coast Guard is part of the Department of Transportation (DOT)) team to expand the maritime Differential Global Positioning System (DGPS) service into a national transportation safety system. The U. S. Coast Guard's role is to implement a Nationwide DGPS (NDGPS) expansion effort to more than double the existing number of broadcast sites. The NDGPS system is designed to meet all surface transportation navigation requirements in the United States and will provide double terrestrial DGPS coverage across the continental United States. The uscg uses 285-325 kHz (Medium Frequency) to broadcast corrections which provide signal for up to 250 nautical miles. Unfortunately, this frequency range typically requires 340-foot towers for short monopole (tenth of a wavelength) implementation typically discussed in textbooks. Because of the unusually long wavelength, several years of consulting, modeling, and testing were required before fully understanding how to meet system requirements given the severe constraints imposed by practical implementation. The electrically short antennae places increased pressure and complexity for the Antenna Tuning Unit (ATU) to maintain a 50 + 0j Ohm load for all weather conditions. Legacy equipment lacks the sophistication to maintain a 50 Ohm, low VSWR condition, resulting in transmitter mismatches, amplifier failures, extended off-air periods, excessive technician call outs and exhausted sparing and depot maintenance. An all weather ATU presents itself as a tool to significantly improve system availability. The desire to develop, build, and field an all weather ATU started with a carefully laid out plan to incorporate the engineering process with the required contracting process to serve as a vehicle to evaluate emerging technology fairly while providing options for design improvement, quality control, and efficient production and fielding. Results are presented from C2CEN baseline testing to prototype evaluation for seven DGPS sites for

关键词： Receiving antennas

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Next generation differential GPS architecture

Next generation differential GPS architecture

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18th International Technical Meeting of the Satellite Division of The Institute of Navigation, ION GNSS 2005

作者： Cleveland, A. Wolfe, D. Parsons, M. Remondi, B. Ferguson, K. Albright, M. U.S. Coast Guard Command and Control Engineering Center XYZs of GPS Inc. Nationwide and Maritime Differential GPS and Short Range Aids to Navigation Projects C2CEN US Coast Guard Institute of Navigation Council as Marine Representative Coast Guard Command and Control Engineering Center Portsmouth VA NDGPS Architecture Modernization FHWA/USCG High Accuracy-NDGPS

The United States Coast Guard is engaged in a project to re-capitalize Reference Station (RS) and Integrity Monitor (IM) equipment used in the Nationwide Differential Global Position System (NDGPS). The Coast Guard in partnership with industry is developing a new software application to run on an open architecture platform as a replacement for legacy equipment. Present commercially available off-the-shelf Differential Global Positioning System (DGPS) RS and IM equipment lacks the open architecture required to support long term goals and future system improvements. The utility of the proposed new hardware architecture and software application is impressive - nearly every aspect of performance and supportability significantly exceeds that of the legacy archetecture. The flexibility of the new hardware and software architectures complement each other to offer promising possibilities for the future. For example, the new hardware architecture uses Ethernet for internal and external site equipment communications. Each Local Area Network (LAN) will be equiped with a router and two 24 port switches. Various levels of password protection are provided to manage security both locally and remotely. While the new software application directly supports the legacy RS-232/422 interfaces to devices such as GPS receivers, a system design goal includes the ability to directly address each device from NCS. With the use of TCP/IP to RS-232/422 port server devices, the system can meet these forward reaching goals while supporting legacy equipment. New system capabilities include remote software management, remote hardware configuration management, and flexible options for management of licenses. The new configurable RS and IM architecture is a PC-based emulation of legacy reference station and integrity monitor equipment. It supports fluid growth and exploitation of new signals, formats, and technology as they become available, while remaining backward compatible with legacy architecture

关键词： Global positioning system

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engineering OPERATIONAL SEQUENCING SYSTEM

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NAVAL ENGINEERS JOURNAL 1970年第6期82卷 65-&页

作者： CALOGERO, R MCMANUS, D Robert Calogero graduated from the University of Maryland with a Bachelor of Science in Electrical Engineering in February 1965. He entered the Magnetic Defense Section of Propulsion Power and Auxiliary Systems Division of the Naval Ship Engineering Center where he had previously served as a summer student engineering aid. In December 1968 he transferred to the Maintenance Management Branch of NAVSHIPS where he assumed responsibility as Manager of the Operational Sequencing System. Calogero is presently in the Engineering Administration Program offered at the George Washington University and is a member of the Association of Senior Engineers of the Naval Ships Systems Command. Donald McManus graduated from the Maine Maritime Academy in 1954 and received his Bachelor of Marine Science Degree Commission in the U. S. Naval Reserve and a USCG Marine Engineer's license. After graduation he sailed as a licensed engineer aboard steam and diesel powered tankers and “dry cargo” vessels engaged in worldwide commercial trade. Upon release from active duty in 1958 he was employed for the next eight and one-half years at the Sun Shipbuilding and Drydock Co. Chester Pa. in various engineering capacities. McManus came to the Naval Ship Engineering Center in December 1966 and is presently employed as a Marine Engineer in the Control Section of Machinery Arrangement and Controls Branch. He is a member of the Association of Senior Engineers of the Naval Ship Systems Command.

The many varied types of engineering plants extent in today's modern Navy requires an ever creasing range and depth of operational knowledge by engineering personnel at all levels of shipboard operations. The engineering Operational Sequencing System (EOSS) provides each of these levels with the required information to enable the engineering plant to respond to any demands placed upon it which are within its design capability. The engineering Operational Sequencing System is a set of systematic and detailed written procedures utilizing charts, instructions and diagrams which provide the information required for the operation of a shipboard propulsion plant. The purpose of this paper will be to define and discuss the EOSS; to describe the system background, current status and future implementation plans.

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