Global Positioning System (GPS): Current status and possible nursery uses

Treesearch

Dick Karsky

2002-01-01

The GPS (Global Positioning System) is a worldwide satellite-positioning system that was funded, installed, and continues to be operated by the U.S. Department of Defense. The navigation signals are provided free and can be used by anyone who has the equipment necessary to receive them.

Estimation of Subdaily Polar Motion with the Global Positioning System During the Spoch '92 Campaign

NASA Technical Reports Server (NTRS)

Ibanez-Meier, R.; Freedman, A. P.; Herring, T. A.; Gross, R. S.; Lichten, S. M.; Lindqwister, U. J.

1994-01-01

Data collected over six days from a worldwide Global Positioning System (GPS) tracking network during the Epoch '92 campaign are used to estimate variations of the Earth's pole position every 30 minutes.

Global Positioning System

DOT National Transportation Integrated Search

2000-08-01

The article examines the international growth of Global Positioning System (GPS), the system that was originally developed more than 20 years ago and is now an $8 billion industry. Its uses include numerous civilian applications around the globe, inc...

GPS dependencies in the transportation sector : an inventory of Global Positioning System dependencies in the transportation sector, best practices for improved robustness of GPS devices, and potential alternative solutions for positioning, navigation and

DOT National Transportation Integrated Search

2016-08-01

The John A. Volpe National Transportation Systems Center (Volpe Center) was asked by the NOAA Office of Space Commercialization to analyze dependencies on Global Positioning System (GPS) positioning, navigation, and timing (PNT) services within the U...

Office of Spaceflight Standard Spaceborne Global Positioning System (GPS) user equipment project

NASA Technical Reports Server (NTRS)

Saunders, Penny E.

1991-01-01

The Global Positioning System (GPS) provides the following: (1) position and velocity determination to support vehicle GN&C, precise orbit determination, and payload pointing; (2) time reference to support onboard timing systems and data time tagging; (3) relative position and velocity determination to support cooperative vehicle tracking; and (4) attitude determination to support vehicle attitude control and payload pointing.

The Mathematics of the Global Positioning System.

ERIC Educational Resources Information Center

Nord, Gail D.; Jabon, David; Nord, John

1997-01-01

Presents an activity that illustrates the application of mathematics to modern navigation and utilizes the Global Positioning System (GPS). GPS is a constellation of 24 satellites that enables receivers to compute their position anywhere on the earth with great accuracy. (DDR)

Application of DGPS for Collision Avoidance in Intelligent Transportation Systems In a Wireless Environment

DOT National Transportation Integrated Search

2001-02-19

The Global Positioning System (GPS) is a satellite based radio-navigation system. A relatively large number of vehicles are already equipped with GPS devices. This project evaluated the application of Global Positing System (GPS) technology in collis...

The Global Positioning System and Its Integration into College Geography Curricula.

ERIC Educational Resources Information Center

Wikle, Thomas A.; Lambert, Dean P.

1996-01-01

Introduces global positioning system (GPS) technology to nonspecialist geographers and recommends a framework for implementing GPS instructional modules in college geography courses. GPS was developed as a worldwide satellite-based system by the U.S. Department of Defense to simplify and improve military and civilian navigation and positioning.…

Sharp conditions for global stability of Lotka-Volterra systems with distributed delays

NASA Astrophysics Data System (ADS)

Faria, Teresa

We give a criterion for the global attractivity of a positive equilibrium of n-dimensional non-autonomous Lotka-Volterra systems with distributed delays. For a class of autonomous Lotka-Volterra systems, we show that such a criterion is sharp, in the sense that it provides necessary and sufficient conditions for the global asymptotic stability independently of the choice of the delay functions. The global attractivity of positive equilibria is established by imposing a diagonal dominance of the instantaneous negative feedback terms, and relies on auxiliary results showing the boundedness of all positive solutions. The paper improves and generalizes known results in the literature, namely by considering systems with distributed delays rather than discrete delays.

Global Positioning Systems: Keeping Us on Track. Resources in Technology.

ERIC Educational Resources Information Center

Valesey, Brigitte G.

1998-01-01

The Global Positioning System is a satellite-based system used to determine location, speed, and precise time in any weather, anywhere on earth. Developed by the U.S. Air Force as a defense system, it is now available for civilian and commercial uses. (JOW)

Triply redundant integrated navigation and asset visibility system

DOEpatents

Smith, Stephen F [Loudon, TN; Moore, James A [Powell, TN

2011-11-29

Methods and apparatus are described for a navigation system. A method includes providing a global positioning system fix having a plurality of tracking parameters; providing a theater positioning system fix; monitoring the plurality of tracking parameters for predetermined conditions; and, when the predetermined conditions are met, sending a notifying signal and switching to the theater positioning system fix as a primary fix. An apparatus includes a system controller; a global positioning system receiver coupled to the system controller; a radio frequency locating receiver coupled to the system controller; and an operator interface coupled to the system controller.

Triply redundant integrated navigation and asset visibility system

DOEpatents

Smith, Stephen F.; Moore, James A.

2013-01-22

Methods and apparatus are described for a navigation system. A method includes providing a global positioning system fix having a plurality of tracking parameters; providing a theater positioning system fix; monitoring the plurality of tracking parameters for predetermined conditions; and, when the predetermined conditions are met, sending a notifying signal and switching to the theater positioning system fix as a primary fix. An apparatus includes a system controller; a global positioning system receiver coupled to the system controller; a radio frequency locating receiver coupled to the system controller; and an operator interface coupled to the system controller.

UNITED STATES DEPARTMENT OF TRANSPORTATION GLOBAL POSITIONING SYSTEM (GPS) ADJACENT BAND COMPATIBILITY ASSESSMENT

DOT National Transportation Integrated Search

2018-04-01

The goal of the U.S. Department of Transportation (DOT) Global Positioning System (GPS) Adjacent Band Compatibility Assessment is to evaluate the maximum transmitted power levels of adjacent band radiofrequency (RF) systems that can be tolerated by G...

76 FR 63714 - Technical Standard Order (TSO)-C129a, Airborne Supplemental Navigation Equipment Using the Global...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-13

..., Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS) AGENCY: Federal Aviation Administration (FAA), DOT ACTION: Notice of cancellation of TSO-C129a, Airborne Supplemental... cancellation of TSO-C129a, Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS...

Miltipath measurements for land mobile satellite service using global positioning system signals

NASA Technical Reports Server (NTRS)

Lemmon, John J.

1988-01-01

A proposed multipath system for the land mobile satellite radio channel using the Global Positioning System (GPS) is presented. The measurement technique and equipment used to make multipath measurements on communications links are briefly described. The system configuration and performance specifications of the proposed measurement system are discussed.

The Ether Wind and the Global Positioning System.

ERIC Educational Resources Information Center

Muller, Rainer

2000-01-01

Explains how students can perform a refutation of the ether theory using information from the Global Positioning System (GPS). Discusses the functioning of the GPS, qualitatively describes how position determination would be affected by an ether wind, and illustrates the pertinent ideas with a simple quantitative model. (WRM)

Global positioning system (GPS) civil monitoring performance specification.

DOT National Transportation Integrated Search

2009-04-30

This Civil Monitoring Performance Specification (CMPS) is published and maintained at : the direction of the Program Manager for Civil Applications, Global Positioning Systems : Wing (GPSW). The purpose of this document is to provide a comprehensive ...

76 FR 2745 - Federal Aviation Administration

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-14

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Eighty-Fourth Meeting: RTCA Special Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 159 meeting: Global Positioning System (GPS). SUMMARY: The FAA is...

Integrated regional changes in arctic climate feedbacks: Implications for the global climate system

USGS Publications Warehouse

McGuire, A.D.; Chapin, F. S.; Walsh, J.E.; Wirth, C.; ,

2006-01-01

The Arctic is a key part of the global climate system because the net positive energy input to the tropics must ultimately be resolved through substantial energy losses in high-latitude regions. The Arctic influences the global climate system through both positive and negative feedbacks that involve physical, ecological, and human systems of the Arctic. The balance of evidence suggests that positive feedbacks to global warming will likely dominate in the Arctic during the next 50 to 100 years. However, the negative feedbacks associated with changing the freshwater balance of the Arctic Ocean might abruptly launch the planet into another glacial period on longer timescales. In light of uncertainties and the vulnerabilities of the climate system to responses in the Arctic, it is important that we improve our understanding of how integrated regional changes in the Arctic will likely influence the evolution of the global climate system. Copyright ?? 2006 by Annual Reviews. All rights reserved.

DoD Permanently Discontinues Procurement of Global Positioning System Selective Availability

DOT National Transportation Integrated Search

2007-09-18

The Department of Defense announced today that it intends to stop procuring Global Positioning System : (GPS) satellites with the capability to intentionally degrade the accuracy of civil signals. : This capability, known as Selective Availability (S...

Report to Congress : recapitalization plan for the nationwide differential global positioning system (NDGPS).

DOT National Transportation Integrated Search

2010-06-01

The U.S. Department of Transportation (DOT) has developed a recpitlaization plan to reduce technical, cost, and programmatic risks of the DOT-funded inland segment of the Nationwide Differential Global Positioning System (NDGPS)

Vulnerability assessment of the transportation infrastructure relying on global positioning system

DOT National Transportation Integrated Search

2001-08-29

This report responds to Presidential Decision Directive 63 concerning assessing the risks to the transportation infrastructure resulting from the degradation or loss of the Global Positioning System (GPS) signal. This study includes analysis of civil...

Using The Global Positioning System For Earth Orbiter and Deep Space Network

NASA Technical Reports Server (NTRS)

Lichten, Stephen M.; Haines, Bruce J.; Young, Lawrence E.; Dunn, Charles; Srinivasan, Jeff; Sweeney, Dennis; Nandi, Sumita; Spitzmesser, Don

1994-01-01

The Global Positioning System (GPS) can play a major role in supporting orbit and trajectory determination for spacecraft in a wide range of applications, including low-Earth, high-earth, and even deep space (interplanetary) tracking.

Use of Global Positioning System for the capture of environmental data.

DOT National Transportation Integrated Search

1995-01-01

The purpose of this study was to determine the feasibility of using the Global Positioning System (GPS), composed of 24 NAVSTAR satellites emitting individually coded radio signals with accurate timing and ephemeris information, to capture environmen...

Global Positioning System (GPS) Receiver Autonomous Integrity Monitoring (RAIM) web service to support Area Navigation (RNAV) flight planning

DOT National Transportation Integrated Search

2008-01-28

The Volpe Center designed, implemented, and deployed a Global Positioning System (GPS) Receiver Autonomous Integrity Monitoring (RAIM) prediction system in the mid 1990s to support both Air Force and Federal Aviation Administration (FAA) use of TSO C...

Technical standing order : airborne supplemental navigation equipment using the global positioning system (GPS)

DOT National Transportation Integrated Search

2001-01-01

This technical standard order (TSO) prescribes the minimum performance standard that airborne supplemental area navigation equipment using the global positioning system (GPS) must meet in order to be identified with the applicable TSO marking. Airbor...

Global Positioning Systems for Personal Travel Surveys - Lexington Area Travel Data Collection Test: Appendixes

DOT National Transportation Integrated Search

1997-09-15

Personal travel and how it changes is of continuing concern to transportation : planners and policy makers. This project, Global Positioning Systems for : Personal Travel Surveys, would combine self-reported information with GPS : recorded informatio...

MDOT implementation plan for global positioning systems (GPS) technology in planning, design, and construction delivery.

DOT National Transportation Integrated Search

2010-09-13

Global Positioning System (GPS) technology offers advantages to transportation agencies in the planning, design and construction stages of project delivery. This research study will develop a guide for Mississippi Department of Transportation (MDOT) ...

Global Positioning System (GPS) civil signal monitoring (CSM) trade study report

DOT National Transportation Integrated Search

2014-03-07

This GPS Civil Signal Monitoring (CSM) Trade Study has been performed at the direction of DOT/FAA Navigation Programs as the agency of reference for consolidating civil monitoring requirements on the Global Positioning System (GPS). The objective of ...

Using the global positioning system to map disturbance patterns of forest harvesting machinery

Treesearch

T.P. McDonald; E.A. Carter; S.E. Taylor

2002-01-01

Abstract: A method was presented to transform sampled machine positional data obtained from a global positioning system (GPS) receiver into a two-dimensional raster map of number of passes as a function of location. The effect of three sources of error in the transformation process were investigated: path sampling rate (receiver sampling frequency);...

Lane-Level Vehicle Positioning : Integrating Diverse Systems for Precision and Reliability

DOT National Transportation Integrated Search

2013-05-13

Integrated global positioning system/inertial navigation system (GPS/INS) technology, the backbone of vehicle positioning systems, cannot provide the precision and reliability needed for vehicle-based, lane-level positioning in all driving environmen...

Existence and global attractivity of positive periodic solutions of periodic n-species Lotka-Volterra competition systems with several deviating arguments.

PubMed

Fan, M; Wang, K; Jiang, D

1999-08-01

In this paper, we study the existence and global attractivity of positive periodic solutions of periodic n-species Lotka-Volterra competition systems. By using the method of coincidence degree and Lyapunov functional, a set of easily verifiable sufficient conditions are derived for the existence of at least one strictly positive (componentwise) periodic solution of periodic n-species Lotka-Volterra competition systems with several deviating arguments and the existence of a unique globally asymptotically stable periodic solution with strictly positive components of periodic n-species Lotka-Volterra competition system with several delays. Some new results are obtained. As an application, we also examine some special cases of the system we considered, which have been studied extensively in the literature. Some known results are improved and generalized.

The Global Positioning System: Theory and operation

NASA Astrophysics Data System (ADS)

Tucker, Lester Plunkett

Scope and method of study. The purpose of this study is to document the theory, development, and training needs of the United States Global Positioning System for the United States Air Force. This subject area had very little information and to assess the United States Air Force training needs required an investigation into existing training accomplished on the Global Positioning System. The United States Air Force has only one place to obtain the data at Headquarters Air Education and Training Command. Findings and conclusion. The United States Air Force, at the time of this study, does not have a theory and operations course dealing with the newest technology advancement in world navigation. Although this new technology is being provided on aircraft in the form of new navigation hardware, no official course of study is provided by the United States Air Force to it's pilots and navigators dealing with theory and operation. Based on the latest reports dealing with the Global Positioning System, a course on the Global Positioning System was developed in the Instructional Systems Design format to provide background information and understanding of this new technology. Readers of this study must be aware that the information contained in this study is very dynamic. Technology is advancing so fast in this area that it might make this information obsolete in a short amount of time.

IFR approval of differential global positioning system (DGPS) special category I instrument approaches using private ground facilities

DOT National Transportation Integrated Search

1994-08-14

This order identifies specific criteria, not presently found in existing standards, which shall be satisfied before Instrument Flight Rules (IFR) operations can be authorized using differential global positioning systems (DGPS) Special Instrument App...

Global Positioning System for Personal Travel Surveys: Lexington Area Travel Data Collection Test, Final Report

DOT National Transportation Integrated Search

1997-09-15

This report describes the development and field test of an automated data : collection device that includes Global Positioning System (GPS) technology for : the collection of personal travel data. This project configured an automatic : data collectio...

High accuracy-nationwide differential global positioning system test and analysis : phase II report

DOT National Transportation Integrated Search

2005-07-01

The High Accuracy-Nationwide Differential Global Positioning System (HA-NDGPS) program focused on the development of compression and broadcast techniques to provide users over a large area wit very accurate radio navigation solutions. The goal was ac...

Global Positioning Systems (GPS) Technology to Study Vector-Pathogen-Host Interactions

DTIC Science & Technology

2016-12-01

Award Number: W81XWH-11-2-0175 TITLE: Global Positioning Systems (GPS) Technology to Study Vector-Pathogen-Host Interactions PRINCIPAL...Positioning Systems (GPS) Technology to Study Vector-Pathogen-Host Interactions 5b. GRANT NUMBER W81XWH-11-2-0175 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...objective of this project is to examine the evolutionary consequences of introducing a tetravalent live- attenuated dengue virus vaccine into children in

Global Positioning System : significant challenges in sustaining and upgrading widely used capabilities : report to the Subcommittee on National Security and Foreign Affairs, Committee on Oversight and Government Reform, House of Representatives.

DOT National Transportation Integrated Search

2009-04-01

The Global Positioning System (GPS), which provides positioning, navigation, and timing data to users worldwide, has become essential to U.S. national security and a key tool in an expanding array of public service and commercial applications at home...

Positional Accuracy of Airborne Integrated Global Positioning and Inertial Navigation Systems for Mapping in Glen Canyon, Arizona

USGS Publications Warehouse

Sanchez, Richard D.; Hothem, Larry D.

2002-01-01

High-resolution airborne and satellite image sensor systems integrated with onboard data collection based on the Global Positioning System (GPS) and inertial navigation systems (INS) may offer a quick and cost-effective way to gather accurate topographic map information without ground control or aerial triangulation. The Applanix Corporation?s Position and Orientation Solutions for Direct Georeferencing of aerial photography was used in this project to examine the positional accuracy of integrated GPS/INS for terrain mapping in Glen Canyon, Arizona. The research application in this study yielded important information on the usefulness and limits of airborne integrated GPS/INS data-capture systems for mapping.

An accuracy assessment of positions obtained using survey- and recreational-grade Global Positioning System receivers across a range of forest conditions within the Tanana Valley of interior Alaska

Treesearch

Hans-Erik Andersen; Tobey Clarkin; Ken Winterberger; Jacob Strunk

2009-01-01

The accuracy of recreational- and survey-grade global positioning system (GPS) receivers was evaluated across a range of forest conditions in the Tanana Valley of interior Alaska. High-accuracy check points, established using high-order instruments and closed-traverse surveying methods, were then used to evaluate the accuracy of positions acquired in different forest...

Portable device to assess dynamic accuracy of global positioning systems (GPS) receivers used in agricultural aircraft

USDA-ARS?s Scientific Manuscript database

A device was designed to test the dynamic accuracy of Global Positioning System (GPS) receivers used in aerial vehicles. The system works by directing a sun-reflected light beam from the ground to the aircraft using mirrors. A photodetector is placed pointing downward from the aircraft and circuitry...

An Investigation of The Use of Global Positioning System (GPS) Technology and Its Augmentations Within State and Local Transportation Departments

DOT National Transportation Integrated Search

2000-07-01

This report summarizes Global Positioning System (GPS) technology and its augmentation-related activities within State and local transportation agencies. In general, the following items are addressed for each State that participated in this investiga...

The Science and technology Behind Galileo - Europes GPS

NASA Astrophysics Data System (ADS)

Saaj, C.; Underwood, C. I.; Noakes, C.; Park, D. W. G.; Moore, T.

Over recent years, the public has become increasingly aware of the existence of global satellite positioning systems, such as the American Global Positioning System (GPS), for which the generic term is Global Navigation Satellite System (GNSS). This is primarily due to high-profile use in various military conflicts, the acceptance of the technology by the leisure market (hill walking, yachting, etc) and the rapid development of mass-market applications (such as in-vehicle navigation). However, the public is still largely unaware of how GNSS is currently being utilized by researchers across a wide range of scientific applications. The aim of this paper is to provide answers to public's basic questions on GNSS and thereby raise public awareness on the science and technology behind the nascent Galileo project; a European initiative to design, build and deploy a global satellite positioning system similar to the GPS.

Static evaluation of a NAVSTAR Global Positioning System (GPS) (Magnavox Z-Set) receiver, May-September, 1979

DOT National Transportation Integrated Search

1980-05-01

The report documents the results of the static testing of a NAVSTAR Global Positioning System (GPS) single channel sequential receiver (Magnavox Z-Set). These tests were performed at the Coast Guard District 11 office in Long Beach, CA from May to Se...

The Evolution of Global Positioning System (GPS) Technology.

ERIC Educational Resources Information Center

Kumar, Sameer; Moore, Kevin B.

2002-01-01

Describes technological advances in the Global Positioning System (GPS), which is also known as the NAVSTAR GPS satellite constellation program developed in 1937, and changes in the nature of our world by GPS in the areas of agriculture, health, military, transportation, environment, wildlife biology, surveying and mapping, space applications, and…

Teaching High-Accuracy Global Positioning System to Undergraduates Using Online Processing Services

ERIC Educational Resources Information Center

Wang, Guoquan

2013-01-01

High-accuracy Global Positioning System (GPS) has become an important geoscientific tool used to measure ground motions associated with plate movements, glacial movements, volcanoes, active faults, landslides, subsidence, slow earthquake events, as well as large earthquakes. Complex calculations are required in order to achieve high-precision…

The Global Positioning System and Education in the 21st Century.

ERIC Educational Resources Information Center

Wikle, Thomas A.

2000-01-01

Students should have an understanding of basic Global Positioning System (GPS) principles as well as an awareness of how the technology will impact society in the future. Provides a brief overview of the evolution, principles, and applications of GPS together with suggested activities. (Contains 25 references.) (Author/WRM)

INTERIM GUIDANCE FOR DEVELOPING GLOBAL POSITIONING SYSTEM DATA COLLECTION STANDARD OPERATING PROCEDURES AND QUALITY ASSURANCE PROJECT PLANS

EPA Science Inventory

The United States Environmental Protection Agency Geospatial Quality Council developed this document to harmonize the process of collecting, editing, and exporting spatial data of known quality using the Global Positioning System (GPS). Each organizational entity may adopt this d...

The status of accurately locating forest inventory and analysis plots using the Global Positioning System

Treesearch

Michael Hoppus; Andrew Lister

2007-01-01

Historically, field crews used Global Positioning System (GPS) coordinates to establish and relocate plots, as well as document their general location. During the past 5 years, the increase in Geographic Information System (GIS) capabilities and in customer requests to use the spatial relationships between Forest Inventory and Analysis (FIA) plot data and other GIS...

Global Positioning System (GPS) and Geographic Information System (GIS) analysis of mobile harvesting equipment and sediment delivery to streams during forest harvest operations on steep terrain: Experimental design

Treesearch

Daniel Bowker; Jeff Stringer; Chris Barton; Songlin Fei

2011-01-01

Sediment mobilized by forest harvest machine traffic contributes substantially to the degradation of headwater stream systems. This study monitored forest harvest machine traffic to analyze how it affects sediment delivery to stream channels. Harvest machines were outfitted with global positioning system (GPS) dataloggers, recording machine movements and working status...

Orbiter global positioning system design and Ku-band problems investigation, exhibit B, revision 1

NASA Technical Reports Server (NTRS)

Chie, C. M.; Braun, W. R.

1981-01-01

The LinCom effort in supporting the JSC study of the use of the Global Positioning System (GPS) on the space shuttle and in Ku-band problem investigation is documented. LinCom was tasked to evaluate system implementation, performance, and integration aspects of the shuttle GPS and to provide independent technical assessment of reports submitted to JSC regarding integration studies, system studies and navigation analyses.

Nondynamic Tracking Using The Global Positioning System

NASA Technical Reports Server (NTRS)

Yunck, T. P.; Wu, Sien-Chong

1988-01-01

Report describes technique for using Global Positioning System (GPS) to determine position of low Earth orbiter without need for dynamic models. Differential observing strategy requires GPS receiver on user vehicle and network of six ground receivers. Computationally efficient technique delivers decimeter accuracy on orbits down to lowest altitudes. New technique nondynamic long-arc strategy having potential for accuracy of best dynamic techniques while retaining much of computational simplicity of geometric techniques.

The Impact of Estimating High-Resolution Tropospheric Gradients on Multi-GNSS Precise Positioning

PubMed Central

Zhou, Feng; Li, Xingxing; Li, Weiwei; Chen, Wen; Dong, Danan; Wickert, Jens; Schuh, Harald

2017-01-01

Benefits from the modernized US Global Positioning System (GPS), the revitalized Russian GLObal NAvigation Satellite System (GLONASS), and the newly-developed Chinese BeiDou Navigation Satellite System (BDS) and European Galileo, multi-constellation Global Navigation Satellite System (GNSS) has emerged as a powerful tool not only in positioning, navigation, and timing (PNT), but also in remote sensing of the atmosphere and ionosphere. Both precise positioning and the derivation of atmospheric parameters can benefit from multi-GNSS observations. In this contribution, extensive evaluations are conducted with multi-GNSS datasets collected from 134 globally-distributed ground stations of the International GNSS Service (IGS) Multi-GNSS Experiment (MGEX) network in July 2016. The datasets are processed in six different constellation combinations, i.e., GPS-, GLONASS-, BDS-only, GPS + GLONASS, GPS + BDS, and GPS + GLONASS + BDS + Galileo precise point positioning (PPP). Tropospheric gradients are estimated with eight different temporal resolutions, from 1 h to 24 h, to investigate the impact of estimating high-resolution gradients on position estimates. The standard deviation (STD) is used as an indicator of positioning repeatability. The results show that estimating tropospheric gradients with high temporal resolution can achieve better positioning performance than the traditional strategy in which tropospheric gradients are estimated on a daily basis. Moreover, the impact of estimating tropospheric gradients with different temporal resolutions at various elevation cutoff angles (from 3° to 20°) is investigated. It can be observed that with increasing elevation cutoff angles, the improvement in positioning repeatability is decreased. PMID:28368346

The Impact of Estimating High-Resolution Tropospheric Gradients on Multi-GNSS Precise Positioning.

PubMed

Zhou, Feng; Li, Xingxing; Li, Weiwei; Chen, Wen; Dong, Danan; Wickert, Jens; Schuh, Harald

2017-04-03

Benefits from the modernized US Global Positioning System (GPS), the revitalized Russian GLObal NAvigation Satellite System (GLONASS), and the newly-developed Chinese BeiDou Navigation Satellite System (BDS) and European Galileo, multi-constellation Global Navigation Satellite System (GNSS) has emerged as a powerful tool not only in positioning, navigation, and timing (PNT), but also in remote sensing of the atmosphere and ionosphere. Both precise positioning and the derivation of atmospheric parameters can benefit from multi-GNSS observations. In this contribution, extensive evaluations are conducted with multi-GNSS datasets collected from 134 globally-distributed ground stations of the International GNSS Service (IGS) Multi-GNSS Experiment (MGEX) network in July 2016. The datasets are processed in six different constellation combinations, i.e., GPS-, GLONASS-, BDS-only, GPS + GLONASS, GPS + BDS, and GPS + GLONASS + BDS + Galileo precise point positioning (PPP). Tropospheric gradients are estimated with eight different temporal resolutions, from 1 h to 24 h, to investigate the impact of estimating high-resolution gradients on position estimates. The standard deviation (STD) is used as an indicator of positioning repeatability. The results show that estimating tropospheric gradients with high temporal resolution can achieve better positioning performance than the traditional strategy in which tropospheric gradients are estimated on a daily basis. Moreover, the impact of estimating tropospheric gradients with different temporal resolutions at various elevation cutoff angles (from 3° to 20°) is investigated. It can be observed that with increasing elevation cutoff angles, the improvement in positioning repeatability is decreased.

Non-dynamic decimeter tracking of earth satellites using the Global Positioning System

NASA Technical Reports Server (NTRS)

Yunck, T. P.; Wu, S. C.

1986-01-01

A technique is described for employing the Global Positioning System (GPS) to determine the position of a low earth orbiter with decimeter accuracy without the need for user dynamic models. A differential observing strategy is used requiring a GPS receiver on the user vehicle and a network of six ground receivers. The technique uses the continuous record of position change obtained from GPS carrier phase to smooth position measurements made with pseudo-range. The result is a computationally efficient technique that can deliver decimeter accuracy down to the lowest altitude orbits.

77 FR 37430 - BSEE Information Collection Activity: Global Positioning System for MODUs, Extension of a...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-21

... January 2013, and concerns global positioning systems on Mobile Offshore Drilling Units (MODUs). After a... any way. The offshore oil and gas industry will use the information to determine the safest and... to do so. Dated: June 14, 2012. Robert W. Middleton, Deputy Chief, Office of Offshore Regulatory...

Ultra-wideband technology radio frequency interference effects to global positioning system receivers and interference encounter scenario development : second interim report

DOT National Transportation Integrated Search

2001-03-27

The Global Positioning System (GPS) is significant because it is a key element in the development of the Free Flight" air traffic management structure of the future which is needed to enable the expected growth of air travel and alleviate the current...

76 FR 60463 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-29

...; Dual Mode/Global Positioning System Laser-Guided Bombs (16 GBU-10 Enhanced PAVEWAY II or GBU-56 Laser... Munitions (JDAMs) kits; 80 GBU-38 JDAM kits; Dual Mode/Global Positioning System Laser-Guided Bombs (16 GBU... class cluster bomb munition containing sensor fused sub-munitions that are designed to attack and defeat...

Using the Global Positioning System for Earth Orbiter and Deep Space Tracking

NASA Technical Reports Server (NTRS)

Lichten, Stephen M.

1994-01-01

The Global Positioning System (GPS) can play a major role in supporting orbit and trajectory determination for spacecraft in a wide range of applications, including low-Earth, high-Earth, and even deep space (interplanetary) tracking. This paper summarizes recent results demonstrating these unique and far-ranging applications of GPS.

Causes and consequences of timing errors associated with global positioning system collar accelerometer activity monitors

Treesearch

Adam J. Gaylord; Dana M. Sanchez

2014-01-01

Direct behavioral observations of multiple free-ranging animals over long periods of time and large geographic areas is prohibitively difficult. However, recent improvements in technology, such as Global Positioning System (GPS) collars equipped with motion-sensitive activity monitors, create the potential to remotely monitor animal behavior. Accelerometer-equipped...

Compensation for positioning error of industrial robot for flexible vision measuring system

NASA Astrophysics Data System (ADS)

Guo, Lei; Liang, Yajun; Song, Jincheng; Sun, Zengyu; Zhu, Jigui

2013-01-01

Positioning error of robot is a main factor of accuracy of flexible coordinate measuring system which consists of universal industrial robot and visual sensor. Present compensation methods for positioning error based on kinematic model of robot have a significant limitation that it isn't effective in the whole measuring space. A new compensation method for positioning error of robot based on vision measuring technique is presented. One approach is setting global control points in measured field and attaching an orientation camera to vision sensor. Then global control points are measured by orientation camera to calculate the transformation relation from the current position of sensor system to global coordinate system and positioning error of robot is compensated. Another approach is setting control points on vision sensor and two large field cameras behind the sensor. Then the three dimensional coordinates of control points are measured and the pose and position of sensor is calculated real-timely. Experiment result shows the RMS of spatial positioning is 3.422mm by single camera and 0.031mm by dual cameras. Conclusion is arithmetic of single camera method needs to be improved for higher accuracy and accuracy of dual cameras method is applicable.

Helicopter precision approach capability using the Global Positioning System

NASA Technical Reports Server (NTRS)

Kaufmann, David N.

1992-01-01

The period between 1 July and 31 December, 1992, was spent developing a research plan as well as a navigation system document and flight test plan to investigate helicopter precision approach capability using the Global Positioning System (GPS). In addition, all hardware and software required for the research was acquired, developed, installed, and verified on both the test aircraft and the ground-based reference station.

Choosing a Global Positioning System Device for Use in U.S. Army Corps of Engineers Regulatory Districts

DTIC Science & Technology

2017-12-01

Information Systems Center of Expertise (RS/GIS CX) (CEERD-RZR), U.S. Army Engineer Research and Development Center, Cold Regions Research and...GIS Geographic Information Systems GPS Global Positioning System HH Handheld IWR U.S. Army Engineer Institute for Water Resources n/a Not...Applicable NAE U.S. Army New England Regulatory District RS/GIS Remote Sensing/Geographic Information Systems SD Secure Digital SDHC Secure Digital High

Global positioning method based on polarized light compass system

NASA Astrophysics Data System (ADS)

Liu, Jun; Yang, Jiangtao; Wang, Yubo; Tang, Jun; Shen, Chong

2018-05-01

This paper presents a global positioning method based on a polarized light compass system. A main limitation of polarization positioning is the environment such as weak and locally destroyed polarization environments, and the solution to the positioning problem is given in this paper which is polarization image de-noising and segmentation. Therefore, the pulse coupled neural network is employed for enhancing positioning performance. The prominent advantages of the present positioning technique are as follows: (i) compared to the existing position method based on polarized light, better sun tracking accuracy can be achieved and (ii) the robustness and accuracy of positioning under weak and locally destroyed polarization environments, such as cloudy or building shielding, are improved significantly. Finally, some field experiments are given to demonstrate the effectiveness and applicability of the proposed global positioning technique. The experiments have shown that our proposed method outperforms the conventional polarization positioning method, the real time longitude and latitude with accuracy up to 0.0461° and 0.0911°, respectively.

77 FR 72880 - Information Collection Activities: Notice to Lessees and/or Operators (NTL)-Gulf of Mexico OCS...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-06

... Offshore Drilling Units). OMB Control Number: 1014-0013. Abstract: The Outer Continental Shelf (OCS) Lands.... The subject of this ICR is an NTL, GPS (Global Positioning System) for MODUs (Mobile Offshore Drilling... Operators (NTL)--Gulf of Mexico OCS Region--GPS (Global Positioning System) for MODUs (Mobile Offshore...

Effect of forest canopy on GPS-based movement data

Treesearch

Nicholas J. DeCesare; John R. Squires; Jay A. Kolbe

2005-01-01

The advancing role of Global Positioning System (GPS) technology in ecology has made studies of animal movement possible for larger and more vagile species. A simple field test revealed that lengths of GPS-based movement data were strongly biased (P<0.001) by effects of forest canopy. Global Positioning System error added an average of 27.5% additional...

Is Pattern of Life Size-Invariant? Recovering the Underlying Intent of a Walker from Human Walking Trajectory Data

DTIC Science & Technology

2013-07-01

scripted walking actions were recorded using a Global Positioning System (GPS)-enabled BlackBerry (BB) smartphone. GPS data, consisting of latitude and...2014-1239; Cleared 26 March 2014   LIST OF ACRONYMS     AFRL Air Force Research Laboratory BB BlackBerry GPS Global Positioning System

Tracking elk hunters with the Global Positioning System

Treesearch

L. Jack Lyon; Milo G. Burcham

1998-01-01

Global Positioning System (GPS) units were used to record hunter locations at 15 second intervals during elk hunting expeditions. This information allowed us to examine the influence of roads on hunter behavior, and along with associated time and distance data, provide a solid foundation on which a hunter density and elk vulnerability model can be developed.

Getting from Here to There and Knowing Where: Teaching Global Positioning Systems to Students with Visual Impairments

ERIC Educational Resources Information Center

Phillips, Craig L.

2011-01-01

Global Positioning Systems' (GPS) technology is available for individuals with visual impairments to use in wayfinding and address Lowenfeld's "three limitations of blindness." The considerations and methodologies for teaching GPS usage have developed over time as GPS information and devices have been integrated into orientation and mobility…

A Group-learning Approach to Academic and Transferable Skills through an Exercise in the Global Positioning System.

ERIC Educational Resources Information Center

Brown, Giles H.

1999-01-01

Describes a project based on the Global Positioning System (GPS) that offers students a chance to design and implement a mini-research program to prepare them for an undergraduate research project. Discusses the context of the GPS exercise, teaching and learning outcomes, and advantages and evaluation of the exercise. (CMK)

Fast global orbit feedback system in PLS-II

NASA Astrophysics Data System (ADS)

Lee, J.; Kim, C.; Kim, J. M.; Kim, K. R.; Lee, E. H.; Lee, J. W.; Lee, T. Y.; Park, C. D.; Shin, S.; Yoon, J. C.; Cho, W. S.; Park, G. S.; Kim, S. C.

2016-12-01

The transverse position of the electron beam in the Pohang Light Source-II is stabilized by the global orbit feedback system. A slow orbit feedback system has been operating at 2 Hz, and a fast orbit feedback (FOFB) system at 813 Hz was installed recently. This FOFB system consists of 96 electron-beam-position monitors, 48 horizontal fast correctors, 48 vertical fast correctors and Versa Module Europa bus control system. We present the design and implementation of the FOFB system and its test result. Simulation analysis is presented and future improvements are suggested.

Contribution of BeiDou satellite system for long baseline GNSS measurement in Indonesia

NASA Astrophysics Data System (ADS)

Gumilar, I.; Bramanto, B.; Kuntjoro, W.; Abidin, H. Z.; Trihantoro, N. F.

2018-05-01

The demand for more precise positioning method using GNSS (Global Navigation Satellite System) in Indonesia continue to rise. The accuracy of GNSS positioning depends on the length of baseline and the distribution of observed satellites. BeiDou Navigation Satellite System (BDS) is a positioning system owned by China that operating in Asia-Pacific region, including Indonesia. This research aims to find out the contribution of BDS in increasing the accuracy of long baseline static positioning in Indonesia. The contributions are assessed by comparing the accuracy of measurement using only GPS (Global Positioning System) and measurement using the combination of GPS and BDS. The data used is 5 days of GPS and BDS measurement data for baseline with 120 km in length. The software used is open-source RTKLIB and commercial software Compass Solution. This research will explain in detail the contribution of BDS to the accuracy of position in long baseline static GNSS measurement.

Observations of geographically correlated orbit errors for TOPEX/Poseidon using the global positioning system

NASA Technical Reports Server (NTRS)

Christensen, E. J.; Haines, B. J.; Mccoll, K. C.; Nerem, R. S.

1994-01-01

We have compared Global Positioning System (GPS)-based dynamic and reduced-dynamic TOPEX/Poseidon orbits over three 10-day repeat cycles of the ground-track. The results suggest that the prelaunch joint gravity model (JGM-1) introduces geographically correlated errors (GCEs) which have a strong meridional dependence. The global distribution and magnitude of these GCEs are consistent with a prelaunch covariance analysis, with estimated and predicted global rms error statistics of 2.3 and 2.4 cm rms, respectively. Repeating the analysis with the post-launch joint gravity model (JGM-2) suggests that a portion of the meridional dependence observed in JGM-1 still remains, with global rms error of 1.2 cm.

Global attractivity of positive periodic solution to periodic Lotka-Volterra competition systems with pure delay

NASA Astrophysics Data System (ADS)

Tang, Xianhua; Cao, Daomin; Zou, Xingfu

We consider a periodic Lotka-Volterra competition system without instantaneous negative feedbacks (i.e., pure-delay systems) x(t)=x(t)[r(t)-∑j=1na(t)x(t-τ(t))], i=1,2,…,n. We establish some 3/2-type criteria for global attractivity of a positive periodic solution of the system, which generalize the well-known Wright's 3/2 criteria for the autonomous delay logistic equation, and thereby, address the open problem proposed by both Kuang [Y. Kuang, Global stability in delayed nonautonomous Lotka-Volterra type systems without saturated equilibria, Differential Integral Equations 9 (1996) 557-567] and Teng [Z. Teng, Nonautonomous Lotka-Volterra systems with delays, J. Differential Equations 179 (2002) 538-561].

Global Rankings, World-Class Universities and Dilemma in Higher Education Policy in India

ERIC Educational Resources Information Center

Tilak, Jandhyala B. G.

2016-01-01

Global university rankings and world-class universities have become buzzwords almost in every country. Both exercise positive and not-so-positive impact on higher education systems. Universities everywhere are trying hard to improve their status and global rankings. The article reviews some of the important issues related to these two strongly…

Global Positioning System: A Guide for the Approval of GPS Receiver Installation and Operation

DOT National Transportation Integrated Search

1996-10-01

This guide is designed to assist Federal Aviation Adalnlatratlon (FAA) Aviation Safety : Inspectors (ASIs) in evaluating new Global Positioning Systena (GPS) installations and : operations. Because there aro aany documents providing Information, regu...

A Short Tutorial on Inertial Navigation System and Global Positioning System Integration

NASA Technical Reports Server (NTRS)

Smalling, Kyle M.; Eure, Kenneth W.

2015-01-01

The purpose of this document is to describe a simple method of integrating Inertial Navigation System (INS) information with Global Positioning System (GPS) information for an improved estimate of vehicle attitude and position. A simple two dimensional (2D) case is considered. The attitude estimates are derived from sensor data and used in the estimation of vehicle position and velocity through dead reckoning within the INS. The INS estimates are updated with GPS estimates using a Kalman filter. This tutorial is intended for the novice user with a focus on bringing the reader from raw sensor measurements to an integrated position and attitude estimate. An application is given using a remotely controlled ground vehicle operating in assumed 2D environment. The theory is developed first followed by an illustrative example.

Global positioning system for general aviation: Joint FAA-NASA Seminar. [conferences

NASA Technical Reports Server (NTRS)

1978-01-01

Programs to examine and develop means to utilize the global positioning system (GPS) for civil aviation functions are described. User requirements in this regard are discussed, the development of technologies in the areas of antennas, receivers, and signal processors for the GPS are examined, and modifications to the GPS to fit operational and design criteria are evaluated.

An Inquiry-Based Approach to Teaching the Spherical Earth Model to Preservice Teachers Using the Global Positioning System

ERIC Educational Resources Information Center

Song, Youngjin; Schwenz, Richard

2013-01-01

This article describes an inquiry-based lesson to deepen preservice teachers' understanding of the spherical Earth model using the Global Positioning System. The lesson was designed with four learning goals: (1) to increase preservice teachers' conceptual knowledge of the spherical Earth model; (2) to develop preservice teachers'…

The Global Positioning System: Assessing National Policies,

DTIC Science & Technology

1995-01-01

WASSEM • MONICA PINTO CRITICAL TECHNOLOGIES INSTITUTE RAND The research described in this report was supported by RAND’s Critical...MONICA PINTO Prepared for the Executive Office of the President Office of Science and Technology Policy CRITICAL TECHNOLOGIES INSTITUTE RAND...National Research Council Committee on the Future of the Global Positioning System, Washington, D.C., July 28-30,1994. Barbier, Jacques , and Thierry

Finding a Target with an Accessible Global Positioning System

ERIC Educational Resources Information Center

Ponchillia, Paul E.; MacKenzie, Nancy; Long, Richard G.; Denton-Smith, Pamela; Hicks, Thomas L.; Miley, Priscilla

2007-01-01

This article presents two target-location experiments. In the first experiment, 19 participants located a 25-foot chalk circle 93% of the time with a Global Positioning System (GPS) compared to 12% of the time without it. In a single-subject follow-up experiment, the participant came within 1 foot of the target on all GPS trials. Target-location…

HIFiRE-5 Flight Test Preliminary Results (Postprint)

DTIC Science & Technology

2013-11-01

DMARS-R) IMU and Ashtech DG14 Global Positioning System receiver. Results show that a tripped transition occurred on the test article leading edge...Reference System (DMARS-R) IMU and Ashtech DG14 Global Positioning System receiver. Results show that a tripped transition occurred on the test...pitch angle relative to earth as measured by IMU , or flight-path elevation angle as measured by GPS or IMU , degrees  = body-fixed angular coordinate

Requirements for DGPS-based TSPI system used in aircraft noise certification tests

DOT National Transportation Integrated Search

1997-04-30

This letter report addresses that portion of a noise certification applicants Differential Global Positioning System (DGPS-based), Time Space Position Information (TSPI) system which is to be used as a position reference in place of a laser tracke...

Toward an operational water vapor remote sensing system using the global positioning system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutman, S.I.; Chadwick, R.B.; Wolf, d.W.

1995-04-01

Water vapor is one of the most important constituents of the free atmosphere since it is the principal mechanism by which moisture and latent heat are transported and cause weather. Recent experiments have demonstrated that data from Global Positioning System (GPS) satellites can be used to monitor precipitable water vapor (PWV) with millimeter accuracy and sub-hourly temporal resolution. Major advantages of GPS-based systems include the following: they work under virtually all weather conditions; individual systems do not have to be calibrated; and, they are relatively inexpensive.

Global Public Leadership in a Technological Era

ERIC Educational Resources Information Center

Masciulli, Joseph

2011-01-01

Good (ethical and effective) global public leadership--by national politicians, intergovernmental and nongovernmental international organizational leaders, multinational corporate leaders, and technoscientists--will make a significant positive difference in our global system's capacity to solve contemporary and futuristic global problems. High…

International GPS (Global Positioning System) Service for Geodynamics

NASA Technical Reports Server (NTRS)

Zumberge, J. F. (Editor); Liu, R. (Editor); Neilan, R. E. (Editor)

1995-01-01

The International GPS (Global Positioning System) Service for Geodynamics (IGS) began formal operation on January 1, 1994. This first annual report is divided into sections, which mirror different aspects of the service. Section (1) contains general information, including the history of the IGS, its organization, and the global network of GPS tracking sites; (2) contains information on the Central Bureau Information System; (3) describes the International Earth Rotation Service (IERS); (4) details collecting and distributing IGS data in Data Center reports; (6) describes how the IGS Analysis Centers generate their products; (7) contains miscellaneous contributions from other organizations that share common interests with the IGS.

A Self-Tuning Kalman Filter for Autonomous Navigation Using the Global Positioning System (GPS)

NASA Technical Reports Server (NTRS)

Truong, Son H.

1999-01-01

Most navigation systems currently operated by NASA are ground-based, and require extensive support to produce accurate results. Recently developed systems that use Kalman filter and GPS (Global Positioning Systems) data for orbit determination greatly reduce dependency on ground support, and have potential to provide significant economies for NASA spacecraft navigation. These systems, however, still rely on manual tuning from analysts. A sophisticated neuro-fuzzy component fully integrated with the flight navigation system can perform the self-tuning capability for the Kalman filter and help the navigation system recover from estimation errors in real time.

An Observational Study of Tropical Cyclone Spin-Up in Supertyphoon Jangmi and Hurricane Georges

DTIC Science & Technology

2011-12-01

Reconnaissance Squadron stationed at Keesler Air Force Base in Biloxi, Mississippi, and the National Oceanic and Atmospheric Administration (NOAA) Aircraft...implementation of the National Center for Atmospheric Research (NCAR) Global Positioning System (GPS) dropsonde in specialized boundary-layer...transiting the western Pacific, Gulf of Mexico, and Atlantic Ocean basins. 107 APPENDIX A: NCAR GPS DROPSONDES The Global Positioning System (GPS

Navstar Global Positioning System (GPS) clock program: Present and future

NASA Technical Reports Server (NTRS)

Tennant, D. M.

1981-01-01

Global Positioning System (GPS) program status are discussed and plans for ensuring the long term continuation of the program are presented. Performance of GPS clocks is presented in terms of on orbit data as portrayed by GPS master control station kalman filter processing. The GPS Clock reliability program is reviewed in depth and future plans fo the overall clock program are published.

High accuracy autonomous navigation using the global positioning system (GPS)

NASA Technical Reports Server (NTRS)

Truong, Son H.; Hart, Roger C.; Shoan, Wendy C.; Wood, Terri; Long, Anne C.; Oza, Dipak H.; Lee, Taesul

1997-01-01

The application of global positioning system (GPS) technology to the improvement of the accuracy and economy of spacecraft navigation, is reported. High-accuracy autonomous navigation algorithms are currently being qualified in conjunction with the GPS attitude determination flyer (GADFLY) experiment for the small satellite technology initiative Lewis spacecraft. Preflight performance assessments indicated that these algorithms are able to provide a real time total position accuracy of better than 10 m and a velocity accuracy of better than 0.01 m/s, with selective availability at typical levels. It is expected that the position accuracy will be increased to 2 m if corrections are provided by the GPS wide area augmentation system.

Position reporting system using small satellites

NASA Technical Reports Server (NTRS)

Pavesi, B.; Rondinelli, G.; Graziani, F.

1990-01-01

A system able to provide position reporting and monitoring services for mobile applications represents a natural complement to the Global Positioning System (GPS) navigation system. The system architecture is defined on the basis of the communications requirements derived by user needs, allowing maximum flexibility in the use of channel capacity, and a very simple and low cost terminal. The payload is sketched, outlining the block modularity and the use of qualified hardware. The global system capacity is also derived. The spacecraft characteristics are defined on the basis of the payload requirements. A small bus optimized for Ariane IV, Delta II vehicles and based on the modularity concept is presented. The design takes full advantage of each launcher with a common basic bus or bus elements for a mass production.

Geodetic point positioning with GPS (Global Positioning System) carrier beat phase data from the CASA (Central and South America) Uno experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malys, S.; Jensen, P.A.

1990-04-01

The Global Positioning System (GPS) carrier beat phase data collected by the TI4100 GPS receiver has been successfully utilized by the US Defense Mapping Agency in an algorithm which is designed to estimate individual absolute geodetic point positions from data collected over a few hours. The algorithm uses differenced data from one station and two to four GPS satellites at a series of epochs separated by 30 second intervals. The precise GPS ephemerides and satellite clock states, held fixed in the estimation process, are those estimated by the Naval Surface Warfare Center (NSWC). Broadcast ephemerides and clock states are alsomore » utilized for comparative purposes. An outline of the data corrections applied, the mathematical model and the estimation algorithm are presented. Point positioning results and statistics are presented for a globally-distributed set of stations which contributed to the CASA Uno experiment. Statistical assessment of 114 GPS point positions at 11 CASA Uno stations indicates that the overall standard deviation of a point position component, estimated from a few hours of data, is 73 centimeters. Solution of the long line geodetic inverse problem using repeated point positions such as these can potentially offer a new tool for those studying geodynamics on a global scale.« less

Wireless technology applied to GIS

NASA Astrophysics Data System (ADS)

Casademont, Jordi; Lopez-Aguilera, Elena; Paradells, Josep; Rojas, Alfonso; Calveras, Anna; Barceló, Francisco; Cotrina, Josep

2004-07-01

At present, there is a growing interest in wireless applications, due to the fact that the technology begins to support them at reasonable costs. In this paper, we present the technology currently available for use in wireless environments, focusing on Geographic Information Systems. As an example, we present a newly developed platform for the commercialization of advanced geographical information services for use in portable devices. This platform uses available mobile telephone networks and wireless local area networks, but it is completely scalable to new technologies such as third generation mobile networks. Users access the service using a vector map player that runs on a Personal Digital Assistant with wireless access facilities and a Global Positioning System receiver. Before accessing the information, the player will request authorization from the server and download the requested map from it, if necessary. The platform also includes a system for improving Global Positioning System localization with the Real Time Differential Global Positioning System, which uses short GSM messages as the transmission medium.

Dynamics of the stochastic low concentration trimolecular oscillatory chemical system with jumps

NASA Astrophysics Data System (ADS)

Wei, Yongchang; Yang, Qigui

2018-06-01

This paper is devoted to discern long time dynamics through the stochastic low concentration trimolecular oscillatory chemical system with jumps. By Lyapunov technique, this system is proved to have a unique global positive solution, and the asymptotic stability in mean square of such model is further established. Moreover, the existence of random attractor and Lyapunov exponents are obtained for the stochastic homeomorphism flow generated by the corresponding global positive solution. And some numerical simulations are given to illustrate the presented results.

Evaluation of Hardware and Software for a Small Autonomous Underwater Vehicle Navigation System (SANS)

DTIC Science & Technology

1994-09-01

Hyslop , G.L., Schieber, G.E., Schwartz, M.K., "Automated Mission Planning for the Standoff Land Attack Missile (SLAM)", Proceedings of the...1993, pp. 277-290. [PARK80] Parkinson, B.W., "Overview", Global Positioning System, Vol. 1, The Institute of Navigation, Washington, D.C., 1980 , pp...Navigation Message", Global Positioning System, Vol. 1, The Institute of Navigation, Washington, D.C., 1980 , pp. 55-73. 139 [WOOD851 Wooden, W. H

Methods and Apparatus for Reducing Multipath Signal Error Using Deconvolution

NASA Technical Reports Server (NTRS)

Kumar, Rajendra (Inventor); Lau, Kenneth H. (Inventor)

1999-01-01

A deconvolution approach to adaptive signal processing has been applied to the elimination of signal multipath errors as embodied in one preferred embodiment in a global positioning system receiver. The method and receiver of the present invention estimates then compensates for multipath effects in a comprehensive manner. Application of deconvolution, along with other adaptive identification and estimation techniques, results in completely novel GPS (Global Positioning System) receiver architecture.

A Comparative Study of the Ionospheric TEC Measurements Using Global Ionospheric Maps of GPS, TOPEX Radar and the Bent Model

NASA Technical Reports Server (NTRS)

Ho, C.; Wilson, B.; Mannucci, A.; Lindqwister, U.; Yuan, D.

1997-01-01

Global ionospheric mapping (GIM) is a new, emerging technique for determining global ionospheric TEC (total electron content) based on measurements from a worldwide network of Global Positioning System (GPS) receivers.

Global positioning system supported pilot's display

NASA Technical Reports Server (NTRS)

Scott, Marshall M., Jr.; Erdogan, Temel; Schwalb, Andrew P.; Curley, Charles H.

1991-01-01

The hardware, software, and operation of the Microwave Scanning Beam Landing System (MSBLS) Flight Inspection System Pilot's Display is discussed. The Pilot's Display is used in conjunction with flight inspection tests that certify the Microwave Scanning Beam Landing System used at Space Shuttle landing facilities throughout the world. The Pilot's Display was developed for the pilot of test aircraft to set up and fly a given test flight path determined by the flight inspection test engineers. This display also aids the aircraft pilot when hazy or cloud cover conditions exist that limit the pilot's visibility of the Shuttle runway during the flight inspection. The aircraft position is calculated using the Global Positioning System and displayed in the cockpit on a graphical display.

Global positioning system recorder and method

DOEpatents

Hayes, D.W.; Hofstetter, K.J.; Eakle, R.F. Jr.; Reeves, G.E.

1998-12-22

A global positioning system recorder (GPSR) is disclosed in which operational parameters and recorded positional data are stored on a transferable memory element. Through this transferrable memory element, the user of the GPSR need have no knowledge of GPSR devices other than that the memory element needs to be inserted into the memory element slot and the GPSR must be activated. The use of the data element also allows for minimal downtime of the GPSR and the ability to reprogram the GPSR and download data therefrom, without having to physically attach it to another computer. 4 figs.

Global positioning system recorder and method government rights

DOEpatents

Hayes, David W.; Hofstetter, Kenneth J.; Eakle, Jr., Robert F.; Reeves, George E.

1998-01-01

A global positioning system recorder (GPSR) is disclosed in which operational parameters and recorded positional data are stored on a transferable memory element. Through this transferrable memory element, the user of the GPSR need have no knowledge of GPSR devices other than that the memory element needs to be inserted into the memory element slot and the GPSR must be activated. The use of the data element also allows for minimal downtime of the GPSR and the ability to reprogram the GPSR and download data therefrom, without having to physically attach it to another computer.

Global attractivity of non-autonomous Lotka-Volterra competition system without instantaneous negative feedback

NASA Astrophysics Data System (ADS)

Tang, X. H.; Zou, Xingfu

We consider a non-autonomous Lotka-Volterra competition system with distributed delays but without instantaneous negative feedbacks (i.e., pure delay systems). We establish some 3/2-type and M-matrix-type criteria for global attractivity of the positive equilibrium of the system, which generalise and improve the existing ones.

Bathymetric surveys of Morse and Geist Reservoirs in central Indiana made with acoustic Doppler current profiler and global positioning system technology, 1996

USGS Publications Warehouse

Wilson, J.T.; Morlock, S.E.; Baker, N.T.

1997-01-01

Acoustic Doppler current profiler, global positioning system, and geographic information system technology were used to map the bathymetry of Morse and Geist Reservoirs, two artificial lakes used for public water supply in central Indiana. The project was a pilot study to evaluate the use of the technologies for bathymetric surveys. Bathymetric surveys were last conducted in 1978 on Morse Reservoir and in 1980 on Geist Reservoir; those surveys were done with conventional methods using networks of fathometer transects. The 1996 bathymetric surveys produced updated estimates of reservoir volumes that will serve as base-line data for future estimates of storage capacity and sedimentation rates.An acoustic Doppler current profiler and global positioning system receiver were used to collect water-depth and position data from April 1996 through October 1996. All water-depth and position data were imported to a geographic information system to create a data base. The geographic information system then was used to generate water-depth contour maps and to compute the volumes for each reservoir.The computed volume of Morse Reservoir was 22,820 acre-feet (7.44 billion gallons), with a surface area of 1,484 acres. The computed volume of Geist Reservoir was 19,280 acre-feet (6.29 billion gallons), with a surface area of 1,848 acres. The computed 1996 reservoir volumes are less than the design volumes and indicate that sedimentation has occurred in both reservoirs. Cross sections were constructed from the computer-generated surfaces for 1996 and compared to the fathometer profiles from the 1978 and 1980 surveys; analysis of these cross sections also indicates that some sedimentation has occurred in both reservoirs.The acoustic Doppler current profiler, global positioning system, and geographic information system technologies described in this report produced bathymetric maps and volume estimates more efficiently and with comparable or greater resolution than conventional bathymetry methods.

Global Status, Intra-Institutional Stratification and Organizational Segmentation: A Time-Dynamic Tobit Analysis of ARWU Position among U.S. Universities

ERIC Educational Resources Information Center

Cantwell, Brendan; Taylor, Barrett J.

2013-01-01

Ranking systems such as "The Times Higher Education's World University Rankings" and Shanghai Jiao Tong University's "Academic Rankings of World Universities" simultaneously mark global status and stimulate global academic competition. As international ranking systems have become more prominent, researchers have begun to examine whether global…

High precision applications of the global positioning system

NASA Technical Reports Server (NTRS)

Lichten, Stephen M.

1991-01-01

The Global Positioning System (GPS) is a constellation of U.S. defense navigation satellites which can be used for military and civilian positioning applications. A wide variety of GPS scientific applications were identified and precise positioning capabilities with GPS were already demonstrated with data available from the present partial satellite constellation. Expected applications include: measurements of Earth crustal motion, particularly in seismically active regions; measurements of the Earth's rotation rate and pole orientation; high-precision Earth orbiter tracking; surveying; measurements of media propagation delays for calibration of deep space radiometric data in support of NASA planetary missions; determination of precise ground station coordinates; and precise time transfer worldwide.

Critical interactions between Global Fund-supported programmes and health systems: a case study in Papua New Guinea.

PubMed

Rudge, James W; Phuanakoonon, Suparat; Nema, K Henry; Mounier-Jack, Sandra; Coker, Richard

2010-11-01

In Papua New Guinea, investment by the Global Fund to Fight AIDS, Tuberculosis and Malaria (the Global Fund) has played an important role in scaling up the response to HIV and tuberculosis (TB). As part of a series of case studies on how Global Fund-supported programmes interact with national health systems, we assessed the nature and extent of integration of the Global Fund portfolios within the national HIV and TB programmes, the integration of the HIV and TB programmes within the general health system, and system-wide effects of Global Fund support in Papua New Guinea. The study relied on a literature review and 30 interviews with key stakeholders using the Systemic Rapid Assessment Toolkit and thematic analysis. Global Fund-supported activities were found to be largely integrated, or at least coordinated, with the national HIV and TB programmes. However, this has reinforced the vertical nature of these programmes with respect to the general health system, with parallel systems established to meet the demands of programme scale-up and the performance-based nature of Global Fund investment in the weak health system context of Papua New Guinea. The more parallel functions include monitoring and evaluation, and procurement and supply chain systems, while human resources and infrastructure for service delivery are increasingly integrated at more local levels. Positive synergies of Global Fund support include engagement of civil-society partners, and a reliable supply of high-quality drugs which may have increased patient confidence in the health system. However, the severely limited and overburdened pool of human resources has been skewed towards the three diseases, both at management and service delivery levels. There is also concern surrounding the sustainability of the disease programmes, given their dependence on donors. Increasing Global Fund attention towards health system strengthening was viewed positively, but should acknowledge that system changes are slow, difficult to measure and require long-term support.

Spacecraft applications of advanced global positioning system technology

NASA Technical Reports Server (NTRS)

Huth, Gaylord; Dodds, James; Udalov, Sergei; Austin, Richard; Loomis, Peter; Duboraw, I. Newton, III

1988-01-01

The purpose of this study was to evaluate potential uses of Global Positioning System (GPS) in spacecraft applications in the following areas: attitude control and tracking; structural control; traffic control; and time base definition (synchronization). Each of these functions are addressed. Also addressed are the hardware related issues concerning the application of GPS technology and comparisons are provided with alternative instrumentation methods for specific functions required for an advanced low earth orbit spacecraft.

Ionospheric Modelling using GPS to Calibrate the MWA. II: Regional Ionospheric Modelling using GPS and GLONASS to Estimate Ionospheric Gradients

NASA Astrophysics Data System (ADS)

Arora, B. S.; Morgan, J.; Ord, S. M.; Tingay, S. J.; Bell, M.; Callingham, J. R.; Dwarakanath, K. S.; For, B.-Q.; Hancock, P.; Hindson, L.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kapińska, A. D.; Lenc, E.; McKinley, B.; Offringa, A. R.; Procopio, P.; Staveley-Smith, L.; Wayth, R. B.; Wu, C.; Zheng, Q.

2016-07-01

We estimate spatial gradients in the ionosphere using the Global Positioning System and GLONASS (Russian global navigation system) observations, utilising data from multiple Global Positioning System stations in the vicinity of Murchison Radio-astronomy Observatory. In previous work, the ionosphere was characterised using a single-station to model the ionosphere as a single layer of fixed height and this was compared with ionospheric data derived from radio astronomy observations obtained from the Murchison Widefield Array. Having made improvements to our data quality (via cycle slip detection and repair) and incorporating data from the GLONASS system, we now present a multi-station approach. These two developments significantly improve our modelling of the ionosphere. We also explore the effects of a variable-height model. We conclude that modelling the small-scale features in the ionosphere that have been observed with the MWA will require a much denser network of Global Navigation Satellite System stations than is currently available at the Murchison Radio-astronomy Observatory.

Satellite time-transfer: recent developments and projects

NASA Astrophysics Data System (ADS)

Lewandowski, W.; Nawrocki, J.

2006-10-01

Global Navigation Satellite Systems (GNSS) keep a central role in the international timekeeping. American Global Positioning System (GPS) is a navigation system that has proven itself to be a reliable source of positioning for both the military community and the civilian community. But, little known by many, is the fact that GPS has proven itself to be an important and valuable utility to the timekeeping community (Lewandowski et al. 1999). GPS is a versatile and global tool which can be used to both distribute time to an arbitrary number of users and synchronise clocks over large distances with a high degree of precision and accuracy. Similar performance can be obtained with Russian Global Navigation Satellite System (GLONASS). It is expected in the near future satellites of a new European navigation system GALILEO might bring some important opportunities for international timekeeping. This paper after a brief introduction to international timekeeping focuses on the description of recent progress in time transfer techniques using GNSS satellites.

A "Neogeographical Education"? The Geospatial Web, GIS and Digital Art in Adult Education

ERIC Educational Resources Information Center

Papadimitriou, Fivos

2010-01-01

Neogeography provides a link between the science of geography and digital art. The carriers of this link are geospatial technologies (global navigational satellite systems such as the global positioning system, Geographical Information System [GIS] and satellite imagery) along with ubiquitous information and communication technologies (such as…

76 FR 5068 - Establishment of Low Altitude Area Navigation Routes (T-281, T-283, T-285, T-286, and T-288...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-28

... (IFR) approved Global Positioning System (GPS)/Global Navigation Satellite System (GNSS) equipment... only be available for use by GPS/GNSS equipped aircraft. This action enhances safety and facilitates...

Geodetic positioning using a global positioning system of satellites

NASA Technical Reports Server (NTRS)

Fell, P. J.

1980-01-01

Geodetic positioning using range, integrated Doppler, and interferometric observations from a constellation of twenty-four Global Positioning System satellites is analyzed. A summary of the proposals for geodetic positioning and baseline determination is given which includes a description of measurement techniques and comments on rank deficiency and error sources. An analysis of variance comparison of range, Doppler, and interferometric time delay to determine their relative geometric strength for baseline determination is included. An analytic examination to the effect of a priori constraints on positioning using simultaneous observations from two stations is presented. Dynamic point positioning and baseline determination using range and Doppler is examined in detail. Models for the error sources influencing dynamic positioning are developed. Included is a discussion of atomic clock stability, and range and Doppler observation error statistics based on random correlated atomic clock error are derived.

A wireless sensor network based personnel positioning scheme in coal mines with blind areas.

PubMed

Liu, Zhigao; Li, Chunwen; Wu, Danchen; Dai, Wenhan; Geng, Shaobo; Ding, Qingqing

2010-01-01

This paper proposes a novel personnel positioning scheme for a tunnel network with blind areas, which compared with most existing schemes offers both low-cost and high-precision. Based on the data models of tunnel networks, measurement networks and mobile miners, the global positioning method is divided into four steps: (1) calculate the real time personnel location in local areas using a location engine, and send it to the upper computer through the gateway; (2) correct any localization errors resulting from the underground tunnel environmental interference; (3) determine the global three-dimensional position by coordinate transformation; (4) estimate the personnel locations in the blind areas. A prototype system constructed to verify the positioning performance shows that the proposed positioning system has good reliability, scalability, and positioning performance. In particular, the static localization error of the positioning system is less than 2.4 m in the underground tunnel environment and the moving estimation error is below 4.5 m in the corridor environment. The system was operated continuously over three months without any failures.

A Wireless Sensor Network Based Personnel Positioning Scheme in Coal Mines with Blind Areas

PubMed Central

Liu, Zhigao; Li, Chunwen; Wu, Danchen; Dai, Wenhan; Geng, Shaobo; Ding, Qingqing

2010-01-01

This paper proposes a novel personnel positioning scheme for a tunnel network with blind areas, which compared with most existing schemes offers both low-cost and high-precision. Based on the data models of tunnel networks, measurement networks and mobile miners, the global positioning method is divided into four steps: (1) calculate the real time personnel location in local areas using a location engine, and send it to the upper computer through the gateway; (2) correct any localization errors resulting from the underground tunnel environmental interference; (3) determine the global three-dimensional position by coordinate transformation; (4) estimate the personnel locations in the blind areas. A prototype system constructed to verify the positioning performance shows that the proposed positioning system has good reliability, scalability, and positioning performance. In particular, the static localization error of the positioning system is less than 2.4 m in the underground tunnel environment and the moving estimation error is below 4.5 m in the corridor environment. The system was operated continuously over three months without any failures. PMID:22163446

Rapid deployable global sensing hazard alert system

DOEpatents

Cordaro, Joseph V; Tibrea, Steven L; Shull, Davis J; Coleman, Jerry T; Shuler, James M

2015-04-28

A rapid deployable global sensing hazard alert system and associated methods of operation are provided. An exemplary system includes a central command, a wireless backhaul network, and a remote monitoring unit. The remote monitoring unit can include a positioning system configured to determine a position of the remote monitoring unit based on one or more signals received from one or more satellites located in Low Earth Orbit. The wireless backhaul network can provide bidirectional communication capability independent of cellular telecommunication networks and the Internet. An exemplary method includes instructing at least one of a plurality of remote monitoring units to provide an alert based at least in part on a location of a hazard and a plurality of positions respectively associated with the plurality of remote monitoring units.

An introduction to the global positioning system and some geological applications

NASA Technical Reports Server (NTRS)

Dixon, T. H.

1991-01-01

The fundamental principles of the global positioning system (GPS) are reviewed, with consideration given to geological and geophysical applications and related accuracy requirements. Recent improvements are emphasized which relate to areas such as equipment cost, limitations in the GPS satellite constellation, data analysis, uncertainties in satellite orbits and propagation delays, and problems in resolving carrier phase cycle ambiguities. Earthquake processes and near-fault crustal deformation monitoring have been facilitated by advances in GPS data acquisition and analysis. Horizontal positioning capability has been improved by new satellite constellation, better models, and global tracking networks. New classes of tectonic problems may now be studied through GPS, such as kinematic descriptions of crustal deformation and the measurement of relative plate motion at convergent boundaries. Continued improvements in the GPS are foreseen.

Toward a Global Horizontal and Vertical Elastic Load Deformation Model Derived from GRACE and GNSS Station Position Time Series

NASA Astrophysics Data System (ADS)

Chanard, Kristel; Fleitout, Luce; Calais, Eric; Rebischung, Paul; Avouac, Jean-Philippe

2018-04-01

We model surface displacements induced by variations in continental water, atmospheric pressure, and nontidal oceanic loading, derived from the Gravity Recovery and Climate Experiment (GRACE) for spherical harmonic degrees two and higher. As they are not observable by GRACE, we use at first the degree-1 spherical harmonic coefficients from Swenson et al. (2008, https://doi.org/10.1029/2007JB005338). We compare the predicted displacements with the position time series of 689 globally distributed continuous Global Navigation Satellite System (GNSS) stations. While GNSS vertical displacements are well explained by the model at a global scale, horizontal displacements are systematically underpredicted and out of phase with GNSS station position time series. We then reestimate the degree 1 deformation field from a comparison between our GRACE-derived model, with no a priori degree 1 loads, and the GNSS observations. We show that this approach reconciles GRACE-derived loading displacements and GNSS station position time series at a global scale, particularly in the horizontal components. Assuming that they reflect surface loading deformation only, our degree-1 estimates can be translated into geocenter motion time series. We also address and assess the impact of systematic errors in GNSS station position time series at the Global Positioning System (GPS) draconitic period and its harmonics on the comparison between GNSS and GRACE-derived annual displacements. Our results confirm that surface mass redistributions observed by GRACE, combined with an elastic spherical and layered Earth model, can be used to provide first-order corrections for loading deformation observed in both horizontal and vertical components of GNSS station position time series.

Preface: High-rate GNSS: Theory, methods and engineering/geophysical applications

NASA Astrophysics Data System (ADS)

Xu, Peiliang

2017-06-01

Global Navigation Satellite Systems (GNSS) have revolutionized the science and engineering of positioning, timing and navigation and have become an indispensable means to rapidly obtain precise positioning-related information, profoundly affecting our daily life and infrastructure. With GNSS, the position of an object, either stationary or moving, can be determined anywhere, anytime and under any weather condition. In addition to providing a positioning and timing information service, GNSS are now also used to reconstruct physical properties of media through which GNSS signals travel. The utilization of additional GNSS systems such as the European Galileo and the Chinese Beidou (both expected to complete their final global constellations in 2020) will contribute to positioning/navigation science and engineering, provide more industrial opportunities and surely open more challenges.

GPS-based tracking system for TOPEX orbit determination

NASA Technical Reports Server (NTRS)

Melbourne, W. G.

1984-01-01

A tracking system concept is discussed that is based on the utilization of the constellation of Navstar satellites in the Global Positioning System (GPS). The concept involves simultaneous and continuous metric tracking of the signals from all visible Navstar satellites by approximately six globally distributed ground terminals and by the TOPEX spacecraft at 1300-km altitude. Error studies indicate that this system could be capable of obtaining decimeter position accuracies and, most importantly, around 5 cm in the radial component which is key to exploiting the full accuracy potential of the altimetric measurements for ocean topography. Topics covered include: background of the GPS, the precision mode for utilization of the system, past JPL research for using the GPS in precision applications, the present tracking system concept for high accuracy satellite positioning, and results from a proof-of-concept demonstration.

Decision-Making Guide for the Proposed Coast Guard Differential Global Positioning System

DTIC Science & Technology

1991-06-01

DIFFERENTIAL GLOBAL POSITIONING SYSTEM by Robert J. Wilson June, 1991 Thesis Co-Advisors: Dan C. Boger Kurt Schnebele Approved for public release; distribution...Wilson Approved by: -Dan C. Boger, Thesis Co dvisor Kurt Scnebele, CaIn, NOAA, Thesis Co-Advisor -4v David R. Whipple, Chairman Department of...Group, 9 April 1990, Coast Guard Research and Development Center, Groton, CT. 20. Kremer , G.T., and others, ’The Effect of Selective Availability on

A review on bridge dynamic displacement monitoring using global positioning system and accelerometer

NASA Astrophysics Data System (ADS)

Yunus, Mohd Zulkifli Mohd; Ibrahim, Nuremira; Ahmad, Fatimah Shafinaz

2018-02-01

This paper reviews previous research on bridge dynamic displacement monitoring using Global Positioning System (GPS) and an accelerometer for Structural Health Monitoring (SHM) of bridge. These include the review of the advantages and disadvantages of the measurement as well as the methodology of the measurements used in the recent research study. This review could provide a preliminary decision overview for students or researchers before initiating a research related to the bridge dynamic displacement monitoring.

The usefulness of GPS telemetry to study wolf circadian and social activity

USGS Publications Warehouse

Merrill, Samuel B.; Mech, L. David

2003-01-01

This study describes circadian and social movement patterns of 9 wolves and illustrates capabilities and limitations of Global Positioning System (GPS) telemetry for analysis of animal activity patterns. Global Positioning System telemetry was useful in determining when pack members were traveling together or apart and how long a breeding female wolf spent near her pups (e.g., 10-month-old pups were left unattended by their mother for as long as 17 days).

JPL's GNSS Real-Time Earthquake and Tsunami (GREAT) Alert System

NASA Astrophysics Data System (ADS)

Bar-Sever, Yoaz; Miller, Mark; Vallisneri, Michele; Khachikyan, Robert; Meyer, Robert

2017-04-01

We describe recent developments to the GREAT Alert natural hazard monitoring service from JPL's Global Differential GPS (GDGPS) System. GREAT Alert provides real-time, 1 Hz positioning solutions for hundreds of GNSS tracking sites, from both global and regional networks, aiming to monitor ground motion in the immediate aftermath of earthquakes. We take advantage of the centralized data processing, which is collocated with the GNSS orbit determination operations of the GDGPS System, to combine orbit determination with large-scale point-positioning in a grand estimation scheme, and as a result realize significant improvement to the positioning accuracy compared to conventional stand-alone point positioning techniques. For example, the measured median site (over all sites) real-time horizontal positioning accuracy is 2 cm 1DRMS, and the median real-time vertical accuracy is 4 cm RMS. The GREAT Alert positioning service is integrated with automated global earthquake notices from the United States Geodetic Survey (USGS) to support near-real-time calculations of co-seismic displacements with attendant formal errors based both short-term and long-term error analysis for each individual site. We will show the millimeter-level resolution of co-seismic displacement can be achieved by this system. The co-seismic displacements, in turn, are fed into a JPL geodynamics and ocean models, that estimate the Earthquake magnitude and predict the potential tsunami scale.

Modelling Movement Energetics Using Global Positioning System Devices in Contact Team Sports: Limitations and Solutions.

PubMed

Gray, Adrian J; Shorter, Kathleen; Cummins, Cloe; Murphy, Aron; Waldron, Mark

2018-06-01

Quantifying the training and competition loads of players in contact team sports can be performed in a variety of ways, including kinematic, perceptual, heart rate or biochemical monitoring methods. Whilst these approaches provide data relevant for team sports practitioners and athletes, their application to a contact team sport setting can sometimes be challenging or illogical. Furthermore, these methods can generate large fragmented datasets, do not provide a single global measure of training load and cannot adequately quantify all key elements of performance in contact team sports. A previous attempt to address these limitations via the estimation of metabolic energy demand (global energy measurement) has been criticised for its inability to fully quantify the energetic costs of team sports, particularly during collisions. This is despite the seemingly unintentional misapplication of the model's principles to settings outside of its intended use. There are other hindrances to the application of such models, which are discussed herein, such as the data-handling procedures of Global Position System manufacturers and the unrealistic expectations of end users. Nevertheless, we propose an alternative energetic approach, based on Global Positioning System-derived data, to improve the assessment of mechanical load in contact team sports. We present a framework for the estimation of mechanical work performed during locomotor and contact events with the capacity to globally quantify the work done during training and matches.

Global Positioning System surveys of storm-surge sensors deployed during Hurricane Ike, Seadrift, Texas, to Lake Charles, Louisiana, 2008

USGS Publications Warehouse

Payne, Jason; Woodward, Brenda K.; Storm, John B.

2009-01-01

The U.S. Geological Survey installed a network of pressure sensors at 65 sites along the Gulf Coast from Seadrift, Texas, northeast to Lake Charles, Louisiana, to record the timing, areal extent, and magnitude of inland storm surge and coastal flooding caused by Hurricane Ike in September 2008. A Global Positioning System was used to obtain elevations of reference marks near each sensor. A combination of real-time kinematic (RTK) and static Global Positioning System surveys were done to obtain elevations of reference marks. Leveling relative to reference marks was done to obtain elevations of sensor orifices above the reference marks. This report summarizes the Global Positioning System data collected and processed to obtain reference mark and storm-sensor-orifice elevations for 59 storm-surge sensors recovered from the original 65 installed as a necessary prelude to computation of storm-surge elevations. National Geodetic Survey benchmarks were used for RTK surveying. Where National Geodetic Survey benchmarks were not within 12 kilometers of a sensor site, static surveying was done. Additional control points for static surveying were in the form of newly established benchmarks or reestablished existing benchmarks. RTK surveying was used to obtain positions and elevations of reference marks for 29 sensor sites. Static surveying was used to obtain positions and elevations of reference marks for 34 sensor sites; four sites were surveyed using both methods. Multiple quality checks on the RTK-survey and static-survey data were applied. The results of all quality checks indicate that the desired elevation accuracy for the surveys of this report, less than 0.1-meter error, was achieved.

Precise GPS orbits for geodesy

NASA Technical Reports Server (NTRS)

Colombo, Oscar L.

1994-01-01

The Global Positioning System (GPS) has become, in recent years, the main space-based system for surveying and navigation in many military, commercial, cadastral, mapping, and scientific applications. Better receivers, interferometric techniques (DGPS), and advances in post-processing methods have made possible to position fixed or moving receivers with sub-decimeter accuracies in a global reference frame. Improved methods for obtaining the orbits of the GPS satellites have played a major role in these achievements; this paper gives a personal view of the main developments in GPS orbit determination.

Precise positioning with current multi-constellation Global Navigation Satellite Systems: GPS, GLONASS, Galileo and BeiDou.

PubMed

Li, Xingxing; Zhang, Xiaohong; Ren, Xiaodong; Fritsche, Mathias; Wickert, Jens; Schuh, Harald

2015-02-09

The world of satellite navigation is undergoing dramatic changes with the rapid development of multi-constellation Global Navigation Satellite Systems (GNSSs). At the moment more than 70 satellites are already in view, and about 120 satellites will be available once all four systems (BeiDou + Galileo + GLONASS + GPS) are fully deployed in the next few years. This will bring great opportunities and challenges for both scientific and engineering applications. In this paper we develop a four-system positioning model to make full use of all available observations from different GNSSs. The significant improvement of satellite visibility, spatial geometry, dilution of precision, convergence, accuracy, continuity and reliability that a combining utilization of multi-GNSS brings to precise positioning are carefully analyzed and evaluated, especially in constrained environments.

Land Subsidence and Aquifer-System Compaction in the Tucson Active Management Area, South-Central Arizona, 1987-2005

USGS Publications Warehouse

Carruth, Rob; Flynn, Pool; Donald, R.; Anderson, Carl E.

2007-01-01

The U.S. Geological Survey monitors land subsidence and aquifer-system compaction caused by ground-water depletion in Tucson Basin and Avra Valley - two of the three alluvial basins within the Tucson Active Management Area. In spring 1987, the Global Positioning System was used to measure horizontal and vertical positions for bench marks at 43 sites to establish a network for monitoring land subsidence in Tucson Basin and Avra Valley. Between 1987 and 2005, the original number of subsidence monitoring stations was gradually increased to more than 100 stations to meet the need for information in the growing metropolitan area. Data from approximately 60 stations common to the Global Positioning System surveys done after an initial survey in 1987 are used to document land subsidence. For the periods of comparison, average land-surface deformation generally is less than the maximum subsidence at an individual station and takes into account land-surface recovery from elastic aquifer-system compaction. Between 1987 and 1998, as much as 3.2 inches of subsidence occurred in Tucson Basin and as much as 4 inches of subsidence occurred in Avra Valley. For the 31 stations that are common to both the 1987 and 1998 Global Positioning System surveys, the average subsidence during the 11-year period was about 0.5 inch in Tucson Basin and about 1.2 inches in Avra Valley. For the approximately 60 stations that are common to both the 1998 and 2002 Global Positioning System surveys, the data indicate that as much as 3.5 inches of subsidence occurred in Tucson Basin and as much as 1.1 inches of subsidence occurred in Avra Valley. The average subsidence for the 4-year period is about 0.4 inch in Tucson Basin and 0.6 inch in Avra Valley. Between the 2002 and the 2005 Global Positioning System surveys, the data indicate that as much as 0.2 inch of subsidence occurred in Tucson Basin and as much as 2.2 inches of subsidence occurred in Avra Valley. The average subsidence for the 3-year period is about 0.7 inch in Avra Valley. Between 1987 and 2004-05, land subsidence was greater in Avra Valley than in Tucson Basin on the basis of the average cumulative subsidence for the stations that were common to the original Global Positioning System survey in 1987. The average total subsidence during the 17- to 18-year period was about 1.3 inches in Tucson Basin and about 2.8 inches in Avra Valley. Three stations in Tucson Basin showed subsidence greater than 4 inches for the period - 5 inches at stations C45 and X419 and 4.1 inches at station PA4. In Avra Valley, two stations showed subsidence for the 17- to 18-year period greater than 4 inches - 4.3 inches at station AV25 and 4.8 inches at station SA105. In 1983, fourteen wells were fitted with borehole extensometers to monitor water-level fluctuations and aquifer-system compaction. Continuous records of water level and aquifer-system compaction indicate that as much as 45 feet of water-level decline and 4 inches of aquifer-system compaction occurred in Tucson Basin from January 1989 through December, 2005. In Avra Valley, extensometer data indicate that as much as 55 feet of water-level decline and 1.7 inches of aquifer-system compaction occurred during the same time period. Rates of compaction vary throughout the extensometer network, with the greater rates of compaction being associated with areas of greater water-level decline and more compressible sediments. In Avra Valley, data from the Global Positioning System surveys indicate that more than half of the total subsidence of the land surface may be the result of aquifer-system compaction below the portion of the aquifer instrumented with the vertical extensometers. For the area in the northern part of Tucson Basin between the Rillito and Santa Cruz rivers, an Interferometric Synthetic Aperture Radar interferogram indicates that about 1.65 inches of subsidence occurred between 2003 and 2006. Between 2002 and 2004, the Global Positioning System

UAV Data Exchange Test Bed for At-Sea and Ashore Information Systems

DTIC Science & Technology

2014-12-02

29 3.2 Visualization using NASA World Wind . . . . . . . . . . . . . . . . . . . . . . . . 30 3.3 Visualization using Quantum GIS...Data Server and the Global Positioning Warehouse 37 4.1 Naval Position Repository Installation . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.2...4.4 Data Exchange between CSD and NPR . . . . . . . . . . . . . . . . . . . . . . . . 41 5 Maritime Tactical Command and Control 43 5.1 Global Command

Cost analysis of Navy acquisition alternatives for the NAVSTAR Global Positioning System

NASA Astrophysics Data System (ADS)

Darcy, T. F.; Smith, G. P.

1982-12-01

This research analyzes the life cycle cost (LCC) of the Navy's current and two hypothetical procurement alternatives for NAVSTAR Global Positioning System (GPS) user equipment. Costs are derived by the ARINC Research Corporation ACBEN cost estimating system. Data presentation is in a comparative format describing individual alternative LCC and differential costs between alternatives. Sensitivity analysis explores the impact receiver-processor unit (RPU) first unit production cost has on individual alternative LCC, as well as cost differentials between each alternative. Several benefits are discussed that might provide sufficient cost savings and/or system effectiveness improvements to warrant a procurement strategy other than the existing proposal.

Global Positioning System Synchronized Active Light Autonomous Docking System

NASA Technical Reports Server (NTRS)

Howard, Richard T. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor); Bell, Joseph L. (Inventor)

1996-01-01

A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprising at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

Global Positioning System Synchronized Active Light Autonomous Docking System

NASA Technical Reports Server (NTRS)

Howard, Richard (Inventor)

1994-01-01

A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprises at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

Global GNSS processing based on the raw observation approach

NASA Astrophysics Data System (ADS)

Strasser, Sebastian; Zehentner, Norbert; Mayer-Gürr, Torsten

2017-04-01

Many global navigation satellite system (GNSS) applications, e.g. Precise Point Positioning (PPP), require high-quality GNSS products, such as precise GNSS satellite orbits and clocks. These products are routinely determined by analysis centers of the International GNSS Service (IGS). The current processing methods of the analysis centers make use of the ionosphere-free linear combination to reduce the ionospheric influence. Some of the analysis centers also form observation differences, in general double-differences, to eliminate several additional error sources. The raw observation approach is a new GNSS processing approach that was developed at Graz University of Technology for kinematic orbit determination of low Earth orbit (LEO) satellites and subsequently adapted to global GNSS processing in general. This new approach offers some benefits compared to well-established approaches, such as a straightforward incorporation of new observables due to the avoidance of observation differences and linear combinations. This becomes especially important in view of the changing GNSS landscape with two new systems, the European system Galileo and the Chinese system BeiDou, currently in deployment. GNSS products generated at Graz University of Technology using the raw observation approach currently comprise precise GNSS satellite orbits and clocks, station positions and clocks, code and phase biases, and Earth rotation parameters. To evaluate the new approach, products generated using the Global Positioning System (GPS) constellation and observations from the global IGS station network are compared to those of the IGS analysis centers. The comparisons show that the products generated at Graz University of Technology are on a similar level of quality to the products determined by the IGS analysis centers. This confirms that the raw observation approach is applicable to global GNSS processing. Some areas requiring further work have been identified, enabling future improvements of the method.

Global positioning system measurements for crustal deformation: Precision and accuracy

USGS Publications Warehouse

Prescott, W.H.; Davis, J.L.; Svarc, J.L.

1989-01-01

Analysis of 27 repeated observations of Global Positioning System (GPS) position-difference vectors, up to 11 kilometers in length, indicates that the standard deviation of the measurements is 4 millimeters for the north component, 6 millimeters for the east component, and 10 to 20 millimeters for the vertical component. The uncertainty grows slowly with increasing vector length. At 225 kilometers, the standard deviation of the measurement is 6, 11, and 40 millimeters for the north, east, and up components, respectively. Measurements with GPS and Geodolite, an electromagnetic distance-measuring system, over distances of 10 to 40 kilometers agree within 0.2 part per million. Measurements with GPS and very long baseline interferometry of the 225-kilometer vector agree within 0.05 part per million.

Bathymetry of Totten Reservoir, Montezuma County, Colorado, 2011

USGS Publications Warehouse

Kohn, Michael S.

2012-01-01

In order to better characterize the water supply capacity of Totten Reservoir, Montezuma County, Colorado, the U.S. Geological Survey, in cooperation with the Dolores Water Conservancy District, conducted a bathymetric survey of Totten Reservoir. The study was performed in June 2011 using a man-operated boat-mounted multibeam echo sounder integrated with a global positioning system and a terrestrial real-time kinematic global positioning system. The two collected datasets were merged and imported into geographic information system software. A bathymetric map of the reservoir was generated in addition to plots for the stage-area and the stage-volume relations.

Bathymetry of Groundhog Reservoir, Dolores County, Colorado, 2011

USGS Publications Warehouse

Kohn, Michael S.

2012-01-01

In order to better characterize the water supply capacity of Groundhog Reservoir, Dolores County, Colorado, the U.S. Geological Survey, in cooperation with the Dolores Water Conservancy District, conducted a bathymetric survey of Groundhog Reservoir. The study was performed in June 2011 using a man-operated boat-mounted multibeam echo sounder integrated with a global positioning system and a terrestrial real-time kinematic global positioning system. The two collected datasets were merged and imported into geographic information system software. A bathymetric map of the reservoir was generated in addition to plots for the stage-area and the stage-volume relations.

Search for domain wall dark matter with atomic clocks on board global positioning system satellites.

PubMed

Roberts, Benjamin M; Blewitt, Geoffrey; Dailey, Conner; Murphy, Mac; Pospelov, Maxim; Rollings, Alex; Sherman, Jeff; Williams, Wyatt; Derevianko, Andrei

2017-10-30

Cosmological observations indicate that dark matter makes up 85% of all matter in the universe yet its microscopic composition remains a mystery. Dark matter could arise from ultralight quantum fields that form macroscopic objects. Here we use the global positioning system as a ~ 50,000 km aperture dark matter detector to search for such objects in the form of domain walls. Global positioning system navigation relies on precision timing signals furnished by atomic clocks. As the Earth moves through the galactic dark matter halo, interactions with domain walls could cause a sequence of atomic clock perturbations that propagate through the satellite constellation at galactic velocities ~ 300 km s -1 . Mining 16 years of archival data, we find no evidence for domain walls at our current sensitivity level. This improves the limits on certain quadratic scalar couplings of domain wall dark matter to standard model particles by several orders of magnitude.

WLAN Positioning Methods and Supporting Learning Technologies for Mobile Platforms

ERIC Educational Resources Information Center

Melkonyan, Arsen

2013-01-01

Location technologies constitute an essential component of systems design for autonomous operations and control. The Global Positioning System (GPS) works well in outdoor areas, but the satellite signals are not strong enough to penetrate inside most indoor environments. As a result, a new strain of indoor positioning technologies that make use of…

Advancing Technology: GPS and GIS Outreach Training for Agricultural Producers

ERIC Educational Resources Information Center

Flynn, Allison; Arnold, Shannon

2010-01-01

The use of the Global Positioning System (GPS) and Global Information Systems (GIS) has made significant impacts on agricultural production practices. However, constant changes in the technologies require continuing educational updates. The outreach program described here introduces the operation, use, and applications of GPS receivers and GIS…

Global and system-specific resting-state fMRI fluctuations are uncorrelated: principal component analysis reveals anti-correlated networks.

PubMed

Carbonell, Felix; Bellec, Pierre; Shmuel, Amir

2011-01-01

The influence of the global average signal (GAS) on functional-magnetic resonance imaging (fMRI)-based resting-state functional connectivity is a matter of ongoing debate. The global average fluctuations increase the correlation between functional systems beyond the correlation that reflects their specific functional connectivity. Hence, removal of the GAS is a common practice for facilitating the observation of network-specific functional connectivity. This strategy relies on the implicit assumption of a linear-additive model according to which global fluctuations, irrespective of their origin, and network-specific fluctuations are super-positioned. However, removal of the GAS introduces spurious negative correlations between functional systems, bringing into question the validity of previous findings of negative correlations between fluctuations in the default-mode and the task-positive networks. Here we present an alternative method for estimating global fluctuations, immune to the complications associated with the GAS. Principal components analysis was applied to resting-state fMRI time-series. A global-signal effect estimator was defined as the principal component (PC) that correlated best with the GAS. The mean correlation coefficient between our proposed PC-based global effect estimator and the GAS was 0.97±0.05, demonstrating that our estimator successfully approximated the GAS. In 66 out of 68 runs, the PC that showed the highest correlation with the GAS was the first PC. Since PCs are orthogonal, our method provides an estimator of the global fluctuations, which is uncorrelated to the remaining, network-specific fluctuations. Moreover, unlike the regression of the GAS, the regression of the PC-based global effect estimator does not introduce spurious anti-correlations beyond the decrease in seed-based correlation values allowed by the assumed additive model. After regressing this PC-based estimator out of the original time-series, we observed robust anti-correlations between resting-state fluctuations in the default-mode and the task-positive networks. We conclude that resting-state global fluctuations and network-specific fluctuations are uncorrelated, supporting a Resting-State Linear-Additive Model. In addition, we conclude that the network-specific resting-state fluctuations of the default-mode and task-positive networks show artifact-free anti-correlations.

Office of Positioning, Navigation and Timing (PNT) and Spectrum Management Program Overview.

DOT National Transportation Integrated Search

2017-01-01

Civil Global Positioning System (GPS)/PNT Leadership : Coordinate the development of departmental positions on PNT and : spectrum policy and protection from harmful radio frequency : interference and operational degradation of capabilities : ...

Integrating GPS, GYRO, vehicle speed sensor, and digital map to provide accurate and real-time position in an intelligent navigation system

NASA Astrophysics Data System (ADS)

Li, Qingquan; Fang, Zhixiang; Li, Hanwu; Xiao, Hui

2005-10-01

The global positioning system (GPS) has become the most extensively used positioning and navigation tool in the world. Applications of GPS abound in surveying, mapping, transportation, agriculture, military planning, GIS, and the geosciences. However, the positional and elevation accuracy of any given GPS location is prone to error, due to a number of factors. The applications of Global Positioning System (GPS) positioning is more and more popular, especially the intelligent navigation system which relies on GPS and Dead Reckoning technology is developing quickly for future huge market in China. In this paper a practical combined positioning model of GPS/DR/MM is put forward, which integrates GPS, Gyro, Vehicle Speed Sensor (VSS) and digital navigation maps to provide accurate and real-time position for intelligent navigation system. This model is designed for automotive navigation system making use of Kalman filter to improve position and map matching veracity by means of filtering raw GPS and DR signals, and then map-matching technology is used to provide map coordinates for map displaying. In practical examples, for illustrating the validity of the model, several experiments and their results of integrated GPS/DR positioning in intelligent navigation system will be shown for the conclusion that Kalman Filter based GPS/DR integrating position approach is necessary, feasible and efficient for intelligent navigation application. Certainly, this combined positioning model, similar to other model, can not resolve all situation issues. Finally, some suggestions are given for further improving integrated GPS/DR/MM application.

Precise positioning with current multi-constellation Global Navigation Satellite Systems: GPS, GLONASS, Galileo and BeiDou

PubMed Central

Li, Xingxing; Zhang, Xiaohong; Ren, Xiaodong; Fritsche, Mathias; Wickert, Jens; Schuh, Harald

2015-01-01

The world of satellite navigation is undergoing dramatic changes with the rapid development of multi-constellation Global Navigation Satellite Systems (GNSSs). At the moment more than 70 satellites are already in view, and about 120 satellites will be available once all four systems (BeiDou + Galileo + GLONASS + GPS) are fully deployed in the next few years. This will bring great opportunities and challenges for both scientific and engineering applications. In this paper we develop a four-system positioning model to make full use of all available observations from different GNSSs. The significant improvement of satellite visibility, spatial geometry, dilution of precision, convergence, accuracy, continuity and reliability that a combining utilization of multi-GNSS brings to precise positioning are carefully analyzed and evaluated, especially in constrained environments. PMID:25659949

Real-Time Point Positioning Performance Evaluation of Single-Frequency Receivers Using NASA's Global Differential GPS System

NASA Technical Reports Server (NTRS)

Muellerschoen, Ronald J.; Iijima, Byron; Meyer, Robert; Bar-Sever, Yoaz; Accad, Elie

2004-01-01

This paper evaluates the performance of a single-frequency receiver using the 1-Hz differential corrections as provided by NASA's global differential GPS system. While the dual-frequency user has the ability to eliminate the ionosphere error by taking a linear combination of observables, the single-frequency user must remove or calibrate this error by other means. To remove the ionosphere error we take advantage of the fact that the magnitude of the group delay in range observable and the carrier phase advance have the same magnitude but are opposite in sign. A way to calibrate this error is to use a real-time database of grid points computed by JPL's RTI (Real-Time Ionosphere) software. In both cases we evaluate the positional accuracy of a kinematic carrier phase based point positioning method on a global extent.

Technician-free system for image-guided bronchoscopy

NASA Astrophysics Data System (ADS)

Khare, Rahul; Bascom, Rebecca; Higgins, William E.

2013-03-01

Previous studies have shown that guidance systems improve accuracy and reduce skill variation among physicians during bronchoscopy. However, most of these systems suffer from one or more of the following limitations: 1) an attending technician must carefully keep the system position synchronized with the bronchoscope position during the procedure; 2) extra bronchoscope tracking hardware may be required; 3) guidance cannot take place in real time; 4) the guidance system is unable to detect and correct faulty bronchoscope maneuvers; and 5) a resynchronization procedure must be followed after adverse events such as patient cough or dynamic airway collapse. Here, we propose an image-based system for technician-free bronchoscopy guidance that relies on two features. First, our system precomputes a guidance plan that suggests natural bronchoscope maneuvers at every bifurcation leading toward a region of interest (ROI). Second, our system enables bronchoscope position verification that relies on a global-registration algorithm to establish the global bronchoscope position and, thus, provide the physician with updated navigational information during bronchoscopy. The system can handle general navigation to an ROI, as well as adverse events, and is directly controlled by the physician by a foot pedal. Guided bronchoscopy results using airway-tree phantoms and human cases demonstrate the efficacy of the system.

Differential Global Positioning System (DGPS) for Flight Testing (Global Positioning System Differentiel (DGPS) pour les Essais en vol)

DTIC Science & Technology

2008-10-01

pseudorange measurement, ρi p denotes the geometric distance between the stations and satellite, dti denotes the receiver’s clock offsets, di p, denotes the...the DGPS data quality. For this purpose a number of over-sea flight legs were included in the trials. The ASHTECH DGPS altitude data output was both...12 where a short leg of a flight trial is represented (the full horizontal track is shown in Figure C-13). Figure C-12: Latitude Error (TANS – 3

A new model for yaw attitude of Global Positioning System satellites

NASA Technical Reports Server (NTRS)

Bar-Sever, Y. E.

1995-01-01

Proper modeling of the Global Positioning System (GPS) satellite yaw attitude is important in high-precision applications. A new model for the GPS satellite yaw attitude is introduced that constitutes a significant improvement over the previously available model in terms of efficiency, flexibility, and portability. The model is described in detail, and implementation issues, including the proper estimation strategy, are addressed. The performance of the new model is analyzed, and an error budget is presented. This is the first self-contained description of the GPS yaw attitude model.

Tropical-Cyclone Formation: Theory and Idealized Modelling

DTIC Science & Technology

2010-11-01

to saturation at the sea-surface temperature and the positive entropy flux from the ocean surface...and Atmospheric Administration; IFEX = Intensity Forecasting Experiment. 15GFS = NOAA Global Forecasting System ; NOGAPS = Navy Operational Global... Atmospheric Prediction System ; UKMET = United Kingdom Meteorological Office. 16 http://www.met.nps.edu/~mtmontgo/storms2010.html 18 overcomes

Real-Time and Post-Processed Orbit Determination and Positioning

NASA Technical Reports Server (NTRS)

Harvey, Nathaniel E. (Inventor); Lu, Wenwen (Inventor); Miller, Mark A. (Inventor); Bar-Sever, Yoaz E. (Inventor); Miller, Kevin J. (Inventor); Romans, Larry J. (Inventor); Dorsey, Angela R. (Inventor); Sibthorpe, Anthony J. (Inventor); Weiss, Jan P. (Inventor); Bertiger, William I. (Inventor);

Real-Time and Post-Processed Orbit Determination and Positioning

NASA Technical Reports Server (NTRS)

Bar-Sever, Yoaz E. (Inventor); Romans, Larry J. (Inventor); Weiss, Jan P. (Inventor); Gross, Jason (Inventor); Harvey, Nathaniel E. (Inventor); Lu, Wenwen (Inventor); Dorsey, Angela R. (Inventor); Miller, Mark A. (Inventor); Sibthorpe, Anthony J. (Inventor); Bertiger, William I. (Inventor);

Observations and High-Resolution Numerical Simulations of a Non-Developing Tropical Disturbance in the Western North Pacific

DTIC Science & Technology

2013-09-01

potential energy CFSR Climate Forecast System Reanalysis COAMPS Coupled Ocean / Atmosphere Mesoscale Prediction System DA data assimilation DART Data...developing (TCS025) tropical disturbance using the adjoint and tangent linear models for the Coupled Ocean – Atmosphere Mesoscale Prediction System (COAMPS...for Medium-range Weather Forecasts ELDORA ELectra DOppler RAdar EOL Earth Observing Laboratory GPS global positioning system GTS Global

Global exponential stability of positive periodic solution of the n-species impulsive Gilpin-Ayala competition model with discrete and distributed time delays.

PubMed

Zhao, Kaihong

2018-12-01

In this paper, we study the n-species impulsive Gilpin-Ayala competition model with discrete and distributed time delays. The existence of positive periodic solution is proved by employing the fixed point theorem on cones. By constructing appropriate Lyapunov functional, we also obtain the global exponential stability of the positive periodic solution of this system. As an application, an interesting example is provided to illustrate the validity of our main results.

Measuring precise sea level from a buoy using the Global Positioning System

NASA Technical Reports Server (NTRS)

Rocken, Christian; Kelecy, Thomas M.; Born, George H.; Young, Larry E.; Purcell, George H., Jr.; Wolf, Susan Kornreich

1990-01-01

The feasibility of using the Global Positioning System (GPS) for accurate sea surface positioning was examined. An experiment was conducted on the Scripps pier at La Jolla, California from December 13-15, 1989. A GPS-equipped buoy was deployed about 100 m off the pier. Two fixed reference GPS receivers, located on the pier and about 80 km away on Monument Peak, were used to estimate the relative position of the floater. Kinematic GPS processing software, developed at the National Geodetic Survey, and the Jet Propulsion Laboratory's GPS Infrared Processing System software were used to determine the floater position relative to land-fixing receivers. Calculations were made of sea level and ocean wave spectra from GPS measurements. It is found that the GPS sea level for the short 100 m baseline agrees with the PPT sea level at the 1 cm level and has an rms variation of 5 mm over a period of 4 hours.

A study of autonomous satellite navigation methods using the global positioning satellite system

NASA Technical Reports Server (NTRS)

Tapley, B. D.

1980-01-01

Special orbit determination algorithms were developed to accommodate the size and speed limitations of on-board computer systems of the NAVSTAR Global Positioning System. The algorithms use square root sequential filtering methods. A new method for the time update of the square root covariance matrix was also developed. In addition, the time update method was compared with another square root convariance propagation method to determine relative performance characteristics. Comparisions were based on the results of computer simulations of the LANDSAT-D satellite processing pseudo range and pseudo range-rate measurements from the phase one GPS. A summary of the comparison results is presented.

Accurate aircraft wind measurements using the global positioning system (GPS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dobosy, R.J.; Crawford, T.L., McMillen, R.T., Dumas, E.J.

1996-11-01

High accuracy measurements of the spatial distribution of wind speed are required in the study of turbulent exchange between the atmosphere and the earth. The use of a differential global positioning system (GPS) to determine the sensor velocity vector component of wind speed is discussed in this paper. The results of noise and rocking testing are summarized, and fluxes obtained from the GPS-based methods are compared to those measured from systems on towers and airplanes. The GPS-based methods provided usable measurements that compared well with tower and aircraft data at a significantly lower cost. 21 refs., 1 fig., 2 tabs.

Autonomous satellite navigation with the Global Positioning System

NASA Technical Reports Server (NTRS)

Fuchs, A. J.; Wooden, W. H., II; Long, A. C.

1977-01-01

This paper discusses the potential of using the Global Positioning System (GPS) to provide autonomous navigation capability to NASA satellites in the 1980 era. Some of the driving forces motivating autonomous navigation are presented. These include such factors as advances in attitude control systems, onboard science annotation, and onboard gridding of imaging data. Simulation results which demonstrate baseline orbit determination accuracies using GPS data on Seasat, Landsat-D, and the Solar Maximum Mission are presented. Emphasis is placed on identifying error sources such as GPS time, GPS ephemeris, user timing biases, and user orbit dynamics, and in a parametric sense on evaluating their contribution to the orbit determination accuracies.

Marine benefits from NASA's global differential system: sub-meter positioning, anywhere, anytime

NASA Technical Reports Server (NTRS)

Bar-Sever, Y.

2000-01-01

Precise real-time, onboard knowledge of a platform s state (position and velocity) is a critical compponent in many marine applications. This article describes a recent technology development that provides a breakthrough in this capability for platforms carrying a dual-frequency GPS receiver - seamless global coverage and roughly an order of magnitude improvement in accuracy compared to state-of-the-art.

Observing Tropospheric Water Vapor by Radio Occultation using the Global Positioning System

NASA Technical Reports Server (NTRS)

Kursinski, E. R.; Hajj, G. A.; Hardy, K. R.; Romans, L. J.; Schofield, J. T.

1995-01-01

Given the importance of water vapor to weather, climate and hydrology, global humidity observations from satellites are critical. At low latitudes, radio occultation observations of Earth's atmosphere using the Global Positioning System (GPS) satellites allow water vapor profiles to be retrieved with accuracies of 10 to 20% below 6 to 7 km altitude and approx. 5% or better within the boundary layer. GPS observations provide a unique combination of accuracy, vertical resolution (less than or equal to 1 km) and insensitivity to cloud and aerosol particles that is well suited to observations of the lower troposphere. These characteristics combined with the inherent stability of radio occultation observations make it an excellent candidate for the measurement of long term trends.

System and method for acquisition management of subject position information

DOEpatents

Carrender, Curt

2005-12-13

A system and method for acquisition management of subject position information that utilizes radio frequency identification (RF ID) to store position information in position tags. Tag programmers receive position information from external positioning systems, such as the Global Positioning System (GPS), from manual inputs, such as keypads, or other tag programmers. The tag programmers program each position tag with the received position information. Both the tag programmers and the position tags can be portable or fixed. Implementations include portable tag programmers and fixed position tags for subject position guidance, and portable tag programmers for collection sample labeling. Other implementations include fixed tag programmers and portable position tags for subject route recordation. Position tags can contain other associated information such as destination address of an affixed subject for subject routing.

System and method for acquisition management of subject position information

DOEpatents

Carrender, Curt [Morgan Hill, CA

2007-01-23

A system and method for acquisition management of subject position information that utilizes radio frequency identification (RF ID) to store position information in position tags. Tag programmers receive position information from external positioning systems, such as the Global Positioning System (GPS), from manual inputs, such as keypads, or other tag programmers. The tag programmers program each position tag with the received position information. Both the tag programmers and the position tags can be portable or fixed. Implementations include portable tag programmers and fixed position tags for subject position guidance, and portable tag programmers for collection sample labeling. Other implementations include fixed tag programmers and portable position tags for subject route recordation. Position tags can contain other associated information such as destination address of an affixed subject for subject routing.

Correcting for Blood Arrival Time in Global Mean Regression Enhances Functional Connectivity Analysis of Resting State fMRI-BOLD Signals.

PubMed

Erdoğan, Sinem B; Tong, Yunjie; Hocke, Lia M; Lindsey, Kimberly P; deB Frederick, Blaise

2016-01-01

Resting state functional connectivity analysis is a widely used method for mapping intrinsic functional organization of the brain. Global signal regression (GSR) is commonly employed for removing systemic global variance from resting state BOLD-fMRI data; however, recent studies have demonstrated that GSR may introduce spurious negative correlations within and between functional networks, calling into question the meaning of anticorrelations reported between some networks. In the present study, we propose that global signal from resting state fMRI is composed primarily of systemic low frequency oscillations (sLFOs) that propagate with cerebral blood circulation throughout the brain. We introduce a novel systemic noise removal strategy for resting state fMRI data, "dynamic global signal regression" (dGSR), which applies a voxel-specific optimal time delay to the global signal prior to regression from voxel-wise time series. We test our hypothesis on two functional systems that are suggested to be intrinsically organized into anticorrelated networks: the default mode network (DMN) and task positive network (TPN). We evaluate the efficacy of dGSR and compare its performance with the conventional "static" global regression (sGSR) method in terms of (i) explaining systemic variance in the data and (ii) enhancing specificity and sensitivity of functional connectivity measures. dGSR increases the amount of BOLD signal variance being modeled and removed relative to sGSR while reducing spurious negative correlations introduced in reference regions by sGSR, and attenuating inflated positive connectivity measures. We conclude that incorporating time delay information for sLFOs into global noise removal strategies is of crucial importance for optimal noise removal from resting state functional connectivity maps.

Tracking Adolescents With Global Positioning System-Enabled Cell Phones to Study Contextual Exposures and Alcohol and Marijuana Use: A Pilot Study.

PubMed

Byrnes, Hilary F; Miller, Brenda A; Wiebe, Douglas J; Morrison, Christopher N; Remer, Lillian G; Wiehe, Sarah E

2015-08-01

Measuring activity spaces, places adolescents spend time, provides information about relations between contextual exposures and risk behaviors. We studied whether contextual exposures in adolescents' activity spaces differ from contextual risks present in residential contexts and examined relationships between contextual exposures in activity spaces and alcohol/marijuana use. Adolescents (N = 18) aged 16-17 years carried global positioning system (GPS)-enabled smartphones for 1 week, with locations tracked. Activity spaces were created by connecting global positioning system points sequentially and adding buffers. Contextual exposure data (e.g., alcohol outlets) were connected to routes. Adolescents completed texts regarding behaviors. Adolescent activity spaces intersected 24.3 census tracts and contained nine times more alcohol outlets than that of residential census tracts. Outlet exposure in activity spaces was related to drinking. Low-socioeconomic status exposure was related to marijuana use. Findings suggest substantial differences between activity spaces and residential contexts and suggest that activity spaces are relevant for adolescent risk behaviors. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Overview of GPS Adjacent Band Compatibility Assessment

DOT National Transportation Integrated Search

2014-09-18

January 13, 2012 National SpaceBased Positioning, Navigation, and Timing (PNT) Executive Committee (EXCOM) cochair letter to National Telecommunications and Information Administration (NTIA) proposed to draft new Global Positioning System (GPS)...

Benefit-cost assessment of the use of LORAN to mitigate GPS vulnerability for positioning, navigation, and timing services

DOT National Transportation Integrated Search

2004-03-30

In 2001, a Volpe Center study assessed the vulnerability of the transportation system to : loss of the Global Positioning System (GPS).1 Subsequent to this assessment, the : Secretary of the U.S. Department of Transportation initiated an examination ...

A demonstration of centimeter-level monitoring of polar motion with the Global Positioning System

NASA Technical Reports Server (NTRS)

Lindqwister, U. J.; Freedman, A. P.; Blewitt, G.

1992-01-01

Daily estimates of the Earth's pole position were obtained with the Global Positioning System (GPS) by using measurements obtained during the GPS IERS (International Earth Rotation Service) and Geodynamics (GIG'91) experiment from 22 Jan. to 13 Feb. 1991. Data from a globally distributed network consisting of 21 Rogue GPS receivers were chosen for the analysis. A comparison of the GPS polar motion series with nine 24-hour very long baseline interferometry (VLBI) estimates yielded agreement in the day-to-day pole position of about 1.5 cm for both X and Y polar motion. A similar comparison of GPS and satellite laser ranging (SLR) data showed agreement to about 1.0 cm. These preliminary results indicate that polar motion can be determined by GPS independent of, and at a level comparable to, that which is obtained from either VLBI or SLR. Furthermore, GPS can provide these data with a daily frequency that neither alternative technique can readily achieve. Thus, GPS promises to be a powerful tool for determining high-frequency platform parameter variation, essential for the ultraprecise spacecraft-tracking requirements of the coming years.

Relativity in the Global Positioning System.

PubMed

Ashby, Neil

2003-01-01

The Global Positioning System (GPS) uses accurate, stable atomic clocks in satellites and on the ground to provide world-wide position and time determination. These clocks have gravitational and motional frequency shifts which are so large that, without carefully accounting for numerous relativistic effects, the system would not work. This paper discusses the conceptual basis, founded on special and general relativity, for navigation using GPS. Relativistic principles and effects which must be considered include the constancy of the speed of light, the equivalence principle, the Sagnac effect, time dilation, gravitational frequency shifts, and relativity of synchronization. Experimental tests of relativity obtained with a GPS receiver aboard the TOPEX/POSEIDON satellite will be discussed. Recently frequency jumps arising from satellite orbit adjustments have been identified as relativistic effects. These will be explained and some interesting applications of GPS will be discussed.

Autonomous Navigation of the SSTI/Lewis Spacecraft Using the Global Positioning System (GPS)

NASA Technical Reports Server (NTRS)

Hart, R. C.; Long, A. C.; Lee, T.

1997-01-01

The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) is pursuing the application of Global Positioning System (GPS) technology to improve the accuracy and economy of spacecraft navigation. High-accuracy autonomous navigation algorithms are being flight qualified in conjunction with GSFC's GPS Attitude Determination Flyer (GADFLY) experiment on the Small Satellite Technology Initiative (SSTI) Lewis spacecraft, which is scheduled for launch in 1997. Preflight performance assessments indicate that these algorithms can provide a real-time total position accuracy of better than 10 meters (1 sigma) and velocity accuracy of better than 0.01 meter per second (1 sigma), with selective availability at typical levels. This accuracy is projected to improve to the 2-meter level if corrections to be provided by the GPS Wide Area Augmentation System (WAAS) are included.

The effect of tracking network configuration on Global Positioning System (GPS) baseline estimates for the CASA (Central and South America) Uno experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, S.K.; Dixon, T.H.; Freymueller, J.T.

1990-04-01

Geodetic monitoring of subduction of the Nazca and Cocos plates is a goal of the CASA (Central and South America) Global Positioning System (GPS) experiments, and requires measurement of intersite distances (baselines) in excess of 500 km. The major error source in these measurements is the uncertainty in the position of the GPS satellites at the time of observation. A key aspect of the first CASA experiment, CASA Uno, was the initiation of a global network of tracking stations minimize these errors. The authors studied the effect of using various subsets of this global tracking network on long (>100 km)more » baseline estimates in the CASA region. Best results were obtained with a global tracking network consisting of three U.S. fiducial stations, two sites in the southwest pacific and two sites in Europe. Relative to smaller subsets, this global network improved baseline repeatability, resolution of carrier phase cycle ambiguities, and formal errors of the orbit estimates. Describing baseline repeatability for horizontal components as {sigma}=(a{sup 2} + b{sup 2}L{sup 2}){sup 1/2} where L is baseline length, the authors obtained a = 4 and 9 mm and b = 2.8{times}10{sup {minus}8} and 2.3{times}10{sup {minus}8} for north and east components, respectively, on CASA baselines up to 1,000 km in length with this global network.« less

Global and System-Specific Resting-State fMRI Fluctuations Are Uncorrelated: Principal Component Analysis Reveals Anti-Correlated Networks

PubMed Central

Carbonell, Felix; Bellec, Pierre

2011-01-01

Abstract The influence of the global average signal (GAS) on functional-magnetic resonance imaging (fMRI)–based resting-state functional connectivity is a matter of ongoing debate. The global average fluctuations increase the correlation between functional systems beyond the correlation that reflects their specific functional connectivity. Hence, removal of the GAS is a common practice for facilitating the observation of network-specific functional connectivity. This strategy relies on the implicit assumption of a linear-additive model according to which global fluctuations, irrespective of their origin, and network-specific fluctuations are super-positioned. However, removal of the GAS introduces spurious negative correlations between functional systems, bringing into question the validity of previous findings of negative correlations between fluctuations in the default-mode and the task-positive networks. Here we present an alternative method for estimating global fluctuations, immune to the complications associated with the GAS. Principal components analysis was applied to resting-state fMRI time-series. A global-signal effect estimator was defined as the principal component (PC) that correlated best with the GAS. The mean correlation coefficient between our proposed PC-based global effect estimator and the GAS was 0.97±0.05, demonstrating that our estimator successfully approximated the GAS. In 66 out of 68 runs, the PC that showed the highest correlation with the GAS was the first PC. Since PCs are orthogonal, our method provides an estimator of the global fluctuations, which is uncorrelated to the remaining, network-specific fluctuations. Moreover, unlike the regression of the GAS, the regression of the PC-based global effect estimator does not introduce spurious anti-correlations beyond the decrease in seed-based correlation values allowed by the assumed additive model. After regressing this PC-based estimator out of the original time-series, we observed robust anti-correlations between resting-state fluctuations in the default-mode and the task-positive networks. We conclude that resting-state global fluctuations and network-specific fluctuations are uncorrelated, supporting a Resting-State Linear-Additive Model. In addition, we conclude that the network-specific resting-state fluctuations of the default-mode and task-positive networks show artifact-free anti-correlations. PMID:22444074

Environmental charging of spacecraft-tests of thermal control materials for use on the global positioning system flight space vehicle. Part 2: Specimen 6 to 9

NASA Technical Reports Server (NTRS)

Stevens, N. J.; Berkopec, F. D.; Blech, R. A.

1976-01-01

The NASA/USAF program on the Environmental Charging of Spacecraft Surfaces consists, in part, of experimental efforts directed toward evaluating the response of materials to the environmental charged particle flux. Samples of thermal blankets of the type to be used on the Global Positioning System Flight Space Vehicles were tested to determine their response to electron flux. The primary result observed was that no discharges were obtained with the quartz-fiber-fabric-covered multilayer insulation specimen. The taped aluminized polyester grounding system used on all specimens did not appear to grossly deteriorate with time; however, the specimens require specific external pressure to maintain constant grounding system resistance.

Addressing the Influence of Space Weather on Airline Navigation

NASA Technical Reports Server (NTRS)

Sparks, Lawrence

2012-01-01

The advent of satellite-based augmentation systems has made it possible to navigate aircraft safely using radio signals emitted by global navigation satellite systems (GNSS) such as the Global Positioning System. As a signal propagates through the earth's ionosphere, it suffers delay that is proportional to the total electron content encountered along the raypath. Since the magnitude of this total electron content is strongly influenced by space weather, the safety and reliability of GNSS for airline navigation requires continual monitoring of the state of the ionosphere and calibration of ionospheric delay. This paper examines the impact of space weather on GNSS-based navigation and provides an overview of how the Wide Area Augmentation System protects its users from positioning error due to ionospheric disturbances

The role of the oceans in changes of the Earth's climate system

NASA Astrophysics Data System (ADS)

von Schuckmann, K.

2016-12-01

Any changes to the Earth's climate system affect an imbalance of the Earth's energy budget due to natural or human made climate forcing. The current positive Earth's energy imbalance is mostly caused by human activity, and is driving global warming. Variations in the world's ocean heat storage and its associated volume changes are a key factor to gauge global warming, to assess changes in the Earth's energy budget and to estimate contributions to the global sea level budget. Present-day sea-level rise is one of the major symptoms of the current positive Earth Energy Imbalance. Sea level also responds to natural climate variability that is superimposing and altering the global warming signal. The most prominent signature in the global mean sea level interannual variability is caused by El Niño-Southern Oscillation. It has been also shown that sea level variability in other regions of the Indo-Pacific area significantly alters estimates of the rate of sea level rise, i.e. in the Indonesian archipelago. In summary, improving the accuracy of our estimates of global Earth's climate state and variability is critical for advancing the understanding and prediction of the evolution of our climate, and an overview on recent findings on the role of the global ocean in changes of the Earth's climate system with particular focus on sea level variability in the Indo-Pacific region will be given in this contribution.

Tracking of white-tailed deer migration by Global Positioning System

USGS Publications Warehouse

Nelson, M.E.; Mech, L.D.; Frame, P.F.

2004-01-01

Based on global positioning system (GPS) radiocollars in northeastern Minnesota, deer migrated 23-45 km in spring during 31-356 h, deviating a maximum 1.6-4.0 km perpendicular from a straight line of travel between their seasonal ranges. They migrated a minimum of 2.1-18.6 km/day over 11-56 h during 2-14 periods of travel. Minimum travel during 1-h intervals averaged 1.5 km/h. Deer paused 1-12 times, averaging 24 h/pause. Deer migrated similar distances in autumn with comparable rates and patterns of travel.

Implementation and Validation of a Real-Time Wireless Non-Invasive Physiological Monitoring System in a High-G Environment

DTIC Science & Technology

2003-03-01

51 Figure 30. SpO2 vs G Profile...and physiological monitoring. The system will be composed of a shirt having non- invasive physiological sensors , Global Positioning System (GPS...Positioning System (GPS)), and other sensor technology. It is now possible to transmit large amounts of data at a high rate in real-time. These

Differential GPS for air transport: Status

NASA Technical Reports Server (NTRS)

Hueschen, Richard M.

1993-01-01

The presentation presents background on what the Global Navigation Satellite System (GNSS) is, desired target dates for initial GNSS capabilities for aircraft operations, and a description of differential GPS (Global Positioning System). The presentation also presents an overview of joint flight tests conducted by LaRC and Honeywell on an integrated differential GPS/inertial reference unit (IRU) navigation system. The overview describes the system tested and the results of the flight tests. The last item presented is an overview of a current grant with Ohio University from LaRC which has the goal of developing a precision DGPS navigation system based on interferometry techniques. The fundamentals of GPS interferometry are presented and its application to determine attitude and heading and precision positioning are shown. The presentation concludes with the current status of the grant.

Global asymptotic stability of density dependent integral population projection models.

PubMed

Rebarber, Richard; Tenhumberg, Brigitte; Townley, Stuart

2012-02-01

Many stage-structured density dependent populations with a continuum of stages can be naturally modeled using nonlinear integral projection models. In this paper, we study a trichotomy of global stability result for a class of density dependent systems which include a Platte thistle model. Specifically, we identify those systems parameters for which zero is globally asymptotically stable, parameters for which there is a positive asymptotically stable equilibrium, and parameters for which there is no asymptotically stable equilibrium. Copyright © 2011 Elsevier Inc. All rights reserved.

Position Measurement Standard Evaluation

DOT National Transportation Integrated Search

1975-02-01

The objectives of the Position Measurement Standard Program were to collect navigation data from three DME receivers and a low-frequency GLOBAL Navigation system, and evaluate their relative performance against a reference radar. Flight test data dur...

Multi-Unmanned Aerial Vehicle (UAV) Cooperative Fault Detection Employing Differential Global Positioning (DGPS), Inertial and Vision Sensors.

PubMed

Heredia, Guillermo; Caballero, Fernando; Maza, Iván; Merino, Luis; Viguria, Antidio; Ollero, Aníbal

2009-01-01

This paper presents a method to increase the reliability of Unmanned Aerial Vehicle (UAV) sensor Fault Detection and Identification (FDI) in a multi-UAV context. Differential Global Positioning System (DGPS) and inertial sensors are used for sensor FDI in each UAV. The method uses additional position estimations that augment individual UAV FDI system. These additional estimations are obtained using images from the same planar scene taken from two different UAVs. Since accuracy and noise level of the estimation depends on several factors, dynamic replanning of the multi-UAV team can be used to obtain a better estimation in case of faults caused by slow growing errors of absolute position estimation that cannot be detected by using local FDI in the UAVs. Experimental results with data from two real UAVs are also presented.

Global Ionosphere Perturbations Monitored by the Worldwide GPS Network

NASA Technical Reports Server (NTRS)

Ho, C. M.; Manucci, A. T.; Lindqwister, U. J.; Pi, X.

1996-01-01

For the first time, measurements from the Global Positioning System (GPS) worldwide network are employed to study the global ionospheric total electron content(TEC) changes during a magnetic storm (November 26, 1994). These measurements are obtained from more than 60 world-wide GPS stations which continuously receive dual-frequency signals. Based on the delays of the signals, we have generated high resolution global ionospheric maps (GIM) of TEC at 15 minute intervals. Using a differential method comparing storm time maps with quiet time maps, we find that significant TEC increases (the positive effect ) are the major feature in the winter hemisphere during this storm (the maximum percent change relative to quiet times is about 150 percent).

Global Geodesy Using GPS Without Fiducial Sites

NASA Technical Reports Server (NTRS)

Heflin, Michael B.; Blewitt, Geoffrey

1994-01-01

Global Positioning System, GPS, used to make global geodetic measurements without use of fiducial site coordinates. Baseline lengths and geocentric radii for each site determined without having to fix any site coordinates. Given n globally distributed sites, n baseline lengths and n geocentric radii form polyhedron with each site at vertex and with geocenter at intersection of all radii. Geodetic information derived from structure of polyhedron and its change with time. Approach applied to any global geodetic technique.

Measuring and forecasting great tsunamis by GNSS-based vertical positioning of multiple ships

NASA Astrophysics Data System (ADS)

Inazu, D.; Waseda, T.; Hibiya, T.; Ohta, Y.

2016-12-01

Vertical ship positioning by the Global Navigation Satellite System (GNSS) was investigated for measuring and forecasting great tsunamis. We first examined existing GNSS vertical position data of a navigating vessel. The result indicated that by using the kinematic Precise Point Positioning (PPP) method, tsunamis greater than 10^-1 m can be detected from the vertical position of the ship. Based on Automatic Identification System (AIS) data, tens of cargo ships and tankers are regularly identified navigating over the Nankai Trough, southwest of Japan. We then assumed that a future Nankai Trough great earthquake tsunami will be observed by ships at locations based on AIS data. The tsunami forecast capability by these virtual offshore tsunami measurements was examined. A conventional Green's function based inversion was used to determine the initial tsunami height distribution. Tsunami forecast tests over the Nankai Trough were carried out using simulated tsunami data of the vertical positions of multiple cargo ships/tankers on a certain day, and of the currently operating observations by deep-sea pressure gauges and Global Positioning System (GPS) buoys. The forecast capability of ship-based tsunami height measurements alone was shown to be comparable to or better than that using the existing offshore observations.

Modernizing the Mobility Air Force for Tomorrow’s Air Traffic Management System

DTIC Science & Technology

2012-01-01

Decision Support System GLONASS Global’naya Navigatsionnaya Sputnikovaya Sistema [Global Navigation Satellite System] GPS Global Positioning System HF high...spreadsheet, November 2009. Eurocontrol, “Link 2000+ Programme: Frequently Asked Questions,” web page, undated(a). As of June 5, 2012: http...www.eurocontrol.int/faq/link2000 ———, “Link 2000+ Programme,” web page, undated(b). As of June 5, 2012: http://www.eurocontrol.int/programmes/link-2000-programme

High-resolution measurements of surface topography with airborne laser altimetry and the global positioning system

NASA Technical Reports Server (NTRS)

Garvin, James B.; Bufton, Jack L.; Cavanaugh, John F.; Krabill, William B.; Clem, Thomas D.; Frederick, Earl B.; Ward, John L.

1991-01-01

Recently, an airborne lidar system that measures laser pulse time-of-flight and the distortion of the pulse waveform upon reflection from earth surface terrain features was developed and is now operational. This instrument is combined with Global Positioning System (GPS) receivers and a two-axis gyroscope for accurate recovery of aircraft position and pointing attitude. The laser altimeter system is mounted on a high-altitude aircraft platform and operated in a repetitively-pulsed mode for measurements of surface elevation profiles at nadir. The laser transmitter makes use of recently developed short-pulse diode-pumped solid-state laser technology in Q-switched Nd:YAG operating at its fundamental wavelength of 1064 nm. A reflector telescope and silicon avalanche photodiode are the basis of the optical receiver. A high-speed time-interval unit and a separate high-bandwidth waveform digitizer under microcomputer control are used to process the backscattered pulses for measurements of terrain. Other aspects of the lidar system are briefly discussed.

A historical perspective of the Global Transportation Network (GTN)

DOT National Transportation Integrated Search

2000-03-01

This thesis analyzes the changes within the Global Transportation Network (GTN)/In Transit Visibility (ITV) feeder systems and the subsequent ITV they provide by comparing the current position to the past and by examining future trends. Up until now,...

Precision Positioning and Inertial Guidance Sensors. Technology and Operational Aspects

DTIC Science & Technology

1981-03-01

Ueberlingen, GE EVALUATION D’UN SYSTEME EUROPEEN DE NAVIGATION HYBRIDE A - - GYROLASER POUR HELICOPTERE: "SEXTAN" by D Regnault, Centre d’Essais en Vol de...NAVIGATION SYSTEM AND STANDARD STATE ELEMENT DEVIATIONMEASUREMENT SOURCES( Dead-reckoning with position fxP fy 5000 En ]TAS, heading and wind scale...Reproduction Ltd ilarford House. 7-9 Charlotte St. London. WIP JIHD [i Ii THEME A new class of precision positioning systems , including GPS (Global

Development of an accurate transmission line fault locator using the global positioning system satellites

NASA Technical Reports Server (NTRS)

Lee, Harry

1994-01-01

A highly accurate transmission line fault locator based on the traveling-wave principle was developed and successfully operated within B.C. Hydro. A transmission line fault produces a fast-risetime traveling wave at the fault point which propagates along the transmission line. This fault locator system consists of traveling wave detectors located at key substations which detect and time tag the leading edge of the fault-generated traveling wave as if passes through. A master station gathers the time-tagged information from the remote detectors and determines the location of the fault. Precise time is a key element to the success of this system. This fault locator system derives its timing from the Global Positioning System (GPS) satellites. System tests confirmed the accuracy of locating faults to within the design objective of +/-300 meters.

Global Positioning System Bibliography

DTIC Science & Technology

1992-03-01

Nev., November, pp. 110-121. Chrzanowski, A. (1987). " Experiencias con GPS en mediciones de deformaciones." Presented at: Workshop on New Techniques...Material Placed in Open Waters Area 2 - Material Properties Related to Navigation and Dredging Area 3 - Dredge Plant Equipment and Systems Processes Area 4...Positioning System." Proceedings of the Second International Symposium on Problems Related to the Redefinintion of North American Geodetic Networks

Integration of the B-52G Offensive Avionics System (OAS) with the Global Positioning System (GPS)

NASA Astrophysics Data System (ADS)

Foote, A. L.; Pluntze, S. C.

Integration of the B-52G OAS with the GPS has been accomplished by modification of existing OAS software. GPS derived position and velocity data are used to enhance the quality of the OAS inertial and dead reckoning navigation systems. The engineering design and the software development process used to implement this design are presented.

Location-only and use-availability data: analysis methods converge

USGS Publications Warehouse

McDonald, Lyman; Manly, Bryan; Huettmann, Falk; Thogmartin, Wayne

2013-01-01

by the availability of geographical information systems (GIS), global positioning system (GPS) radiotelemetry and public online data access initiatives (e.g. global biodiversity information facility). The papers in this Special Feature are intended to present the state of the methodological art in their subject area, with particular attention paid to contrasting the advantages and disadvantages of alternative methods of analysis for data.

Processing Satellite Data for Slant Total Electron Content Measurements

NASA Technical Reports Server (NTRS)

Stephens, Philip John (Inventor); Komjathy, Attila (Inventor); Wilson, Brian D. (Inventor); Mannucci, Anthony J. (Inventor)

2016-01-01

A method, system, and apparatus provide the ability to estimate ionospheric observables using space-borne observations. Space-borne global positioning system (GPS) data of ionospheric delay are obtained from a satellite. The space-borne GPS data are combined with ground-based GPS observations. The combination is utilized in a model to estimate a global three-dimensional (3D) electron density field.

The Role of Trust and Interaction in Global Positioning System Related Accidents

NASA Technical Reports Server (NTRS)

Johnson, Chris W.; Shea, Christine; Holloway, C. Michael

2008-01-01

The Global Positioning System (GPS) uses a network of satellites to calculate the position of a receiver over time. This technology has revolutionized a wide range of safety-critical industries and leisure applications. These systems provide diverse benefits; supplementing the users existing navigation skills and reducing the uncertainty that often characterizes many route planning tasks. GPS applications can also help to reduce workload by automating tasks that would otherwise require finite cognitive and perceptual resources. However, the operation of these systems has been identified as a contributory factor in a range of recent accidents. Users often come to rely on GPS applications and, therefore, fail to notice when they develop faults or when errors occur in the other systems that use the data from these systems. Further accidents can stem from the over confidence that arises when users assume automated warnings will be issued when they stray from an intended route. Unless greater attention is paid to the role of trust and interaction in GPS applications then there is a danger that we will see an increasing number of these failures as positioning technologies become integral in the functioning of increasing numbers of applications.

VELOC - A new kind of information system

NASA Astrophysics Data System (ADS)

Dittloff, H. J.; Keuser, H.; Langer, H.

Based on the Global Positioning System (GPS), VELOC (Vehicle Location) is designed to be a vehicle information system for fleet management adaptable to various user groups, e.g., haulage and delivery companies, and service enterprises with vehicle fleets. The needs of these groups vary with respect to position accuracy, position update rate, and type of communication. The authors describe the requirements, specifications, and performance of VELOC. Special emphasis is placed on some substantial features of the VELOC center, namely the integration of DGPS, a comfortable user interface, and handling of vehicle positions on digital maps.

Distribution of the GNSS-LEO occultation events over Egypt

NASA Astrophysics Data System (ADS)

Ghoniem, Ibrahim; Mousa, Ashraf El-Kutb; El-Fiky, Gamal

2017-06-01

The space-based GNSS RO technique is a promising tool for monitoring the Earth's atmosphere and ionosphere (Mousa et al., 2006). The current paper presents the distribution of the occultation events over Egypt using the operating LEO satellites and GNSS by its two operating systems. By the present research, Egypt could raise NWP Models efficiency by improving meteorological data quality. Twenty operating LEO missions (e.g. Argentinean SAC-C, European MetOp-A, German TerraSAR-X, Indian OceanSat-2, etc.) sent by different countries all over the world were used to derive the occultation events position through Egypt borders by receiving signal from the American global positioning system (GPS) and the Russian global navigation satellite system (GLONASS). Approximately 20,000 km Altitude satellites are transmitting enormous number of rays by the day to approximately 800 km satellites passing by the Earth atmosphere. Our mission is to derive all of these rays position (start and end) by calculating satellites position by the time, determine the rays in the occultation case and derive the atmosphere tangent point position for all occultating rays on the Earth surface (Occultation Events).

A New Indoor Positioning System Architecture Using GPS Signals.

PubMed

Xu, Rui; Chen, Wu; Xu, Ying; Ji, Shengyue

2015-04-29

The pseudolite system is a good alternative for indoor positioning systems due to its large coverage area and accurate positioning solution. However, for common Global Positioning System (GPS) receivers, the pseudolite system requires some modifications of the user terminals. To solve the problem, this paper proposes a new pseudolite-based indoor positioning system architecture. The main idea is to receive real-world GPS signals, repeat each satellite signal and transmit those using indoor transmitting antennas. The transmitted GPS-like signal can be processed (signal acquisition and tracking, navigation data decoding) by the general receiver and thus no hardware-level modification on the receiver is required. In addition, all Tx can be synchronized with each other since one single clock is used in Rx/Tx. The proposed system is simulated using a software GPS receiver. The simulation results show the indoor positioning system is able to provide high accurate horizontal positioning in both static and dynamic situations.

Space Station communications and tracking system

NASA Technical Reports Server (NTRS)

Dietz, Reinhold H.

1987-01-01

A comprehensive description of the existing Space Station communications and tracking system requirements, architecture, and design concepts is provided. Areas which will require innovative solutions to provide cost-effective flight systems are emphasized. Among these are the space-to-space links, the differential global positioning system for determining relative position with free-flying vehicles, multitarget radar, packet/isochronous signal processing, and laser docking systems. In addition, the importance of advanced development, tests, and analyses is summarized.

Two-dimensional measures of accuracy in navigational systems

DOT National Transportation Integrated Search

1987-03-31

Two-dimensional measures generally used to depict the accuracy of radiolocation and navigation systems are described in the report. Application to the NAVSTAR Global Positioning System (GPS) is considered, with a number of geometric illustrations.

The International GPS Network for Charting the Evolving Global Reference Frame

NASA Technical Reports Server (NTRS)

Zumberge, J. F.; Heflin, M. B.; Lindqwister, U. J.; Neilan, R. E.; Watkins, M. M.

1995-01-01

The Telecommunications and Engineering Division of Caltech's Jet Propulsion Laboratory is funded by the National Aeronautics and Space Administration to play a variety of roles in applying the Global Positioning System (GPS) to geodesy and geodynamics. Among these are the operation of dozens of globally-distributed, permanently-operating Earth fixed GPS stations. This, and other applications are described.

Study on Mobile Object Positioning and Alarming System Based on the “Map World” in the Core Area of the Silk Road Economic Belt

NASA Astrophysics Data System (ADS)

Mu, Kai

2017-02-01

The established “Map World” on the National Geographic Information Public Service Platform offers free access to many geographic information in the Core Area of the Silk Road Economic Belt. Considering the special security situation and severe splittism and anti-splittism struggles in the Core Area of the Silk Road Economic Belt, a set of moving target positioning and alarming platform based on J2EE platform and B/S structure was designed and realized by combining the “Map World” data and global navigation satellite system. This platform solves various problems, such as effective combination of Global Navigation Satellite System (GNSS) and “Map World” resources, moving target alarming setting, inquiry of historical routes, system management, etc.

Integrating remote sensing, geographic information systems and global positioning system techniques with hydrological modeling

NASA Astrophysics Data System (ADS)

Thakur, Jay Krishna; Singh, Sudhir Kumar; Ekanthalu, Vicky Shettigondahalli

2017-07-01

Integration of remote sensing (RS), geographic information systems (GIS) and global positioning system (GPS) are emerging research areas in the field of groundwater hydrology, resource management, environmental monitoring and during emergency response. Recent advancements in the fields of RS, GIS, GPS and higher level of computation will help in providing and handling a range of data simultaneously in a time- and cost-efficient manner. This review paper deals with hydrological modeling, uses of remote sensing and GIS in hydrological modeling, models of integrations and their need and in last the conclusion. After dealing with these issues conceptually and technically, we can develop better methods and novel approaches to handle large data sets and in a better way to communicate information related with rapidly decreasing societal resources, i.e. groundwater.

High-Precision Global Geodetic Systems: Revolution And Revelation In Fluid And 'Solid' Earth Tracking (Invited)

NASA Astrophysics Data System (ADS)

Minster, J. H.; Altamimi, Z.; Blewitt, G.; Carter, W. E.; Cazenave, A. A.; Davis, J. L.; Dragert, H.; Feary, D. A.; Herring, T.; Larson, K. M.; Ries, J. C.; Sandwell, D. T.; Wahr, J. M.

2009-12-01

Over the past half-century, space geodetic technologies have changed profoundly the way we look at the planet, not only in the matter of details and accuracy, but also in the matter of how the entire planet changes with time, even on “human” time scales. The advent of space geodesy has provided exquisite images of the ever-changing land and ocean topography and global gravity field of the planet. We now enjoy an International Terrestrial Reference System with a time-dependent geocenter position accurate to a few millimeters. We can image small and large tectonic deformations of the surface before, during, and after earthquakes and volcanic eruptions. We measure both the past subtle changes as well as the recent dramatic changes in the ice sheets, and track global and regional sea-level change to a precision of a millimeter per year or better. The remarkable achievements of Earth observing missions over the past two decades, and the success of future international missions described in the Decadal Survey depend both implicitly and explicitly on the continued availability and enhancement of a reliable and resilient global infrastructure for precise geodesy, and on ongoing advances in geodetic science that are linked to it. This allows us to deal with global scientific, technological and social issues such as climate change and natural hazards, but the impact of the global precise geodetic infrastructure also permeates our everyday lives. Nowadays drivers, aviators, and sailors can determine their positions inexpensively to meter precision in real time, anywhere on the planet. In the foreseeable future, not only will we be able to know a vehicle’s position to centimeter accuracy in real time, but also to control that position, and thus introduce autonomous navigation systems for many tasks which are beyond the reach of “manual” navigation capabilities. This vision will only be realized with sustained international support of the precise global geodetic infrastructure, of the associated technological advances, and of the concomitant fundamental geodetic research.

A Survey of Dual-Use Issues,

DTIC Science & Technology

1996-03-01

positioning systems used for navigation, aircraft engines , and most medical and safety equipment used by DoD. Some modified commercial products are similar...supercomputers, commercial jet aircraft and aircraft engines , the global positioning system (GPS), and composite materials.13 In each of these...turbine engine technologies capable of delivering double the propulsion performance of current systems by the year 2000. The plan to reach this goal is

Late-time behaviour of the Einstein–Boltzmann system with a positive cosmological constant

NASA Astrophysics Data System (ADS)

Lee, Ho; Nungesser, Ernesto

2018-01-01

In this paper we study the Einstein–Boltzmann system for Israel particles with a positive cosmological constant. We consider spatially homogeneous solutions of all Bianchi types except type IX and obtain future global existence and the asymptotic behaviour of solutions to the Einstein–Boltzmann system. The result shows that the solutions converge to the de Sitter solution at late times.

Testing a Coupled Global-limited-area Data Assimilation System using Observations from the 2004 Pacific Typhoon Season

NASA Astrophysics Data System (ADS)

Holt, C. R.; Szunyogh, I.; Gyarmati, G.; Hoffman, R. N.; Leidner, M.

2011-12-01

Tropical cyclone (TC) track and intensity forecasts have improved in recent years due to increased model resolution, improved data assimilation, and the rapid increase in the number of routinely assimilated observations over oceans. The data assimilation approach that has received the most attention in recent years is Ensemble Kalman Filtering (EnKF). The most attractive feature of the EnKF is that it uses a fully flow-dependent estimate of the error statistics, which can have important benefits for the analysis of rapidly developing TCs. We implement the Local Ensemble Transform Kalman Filter algorithm, a vari- ation of the EnKF, on a reduced-resolution version of the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) model and the NCEP Regional Spectral Model (RSM) to build a coupled global-limited area anal- ysis/forecast system. This is the first time, to our knowledge, that such a system is used for the analysis and forecast of tropical cyclones. We use data from summer 2004 to study eight tropical cyclones in the Northwest Pacific. The benchmark data sets that we use to assess the performance of our system are the NCEP Reanalysis and the NCEP Operational GFS analyses from 2004. These benchmark analyses were both obtained by the Statistical Spectral Interpolation, which was the operational data assimilation system of NCEP in 2004. The GFS Operational analysis assimilated a large number of satellite radiance observations in addition to the observations assimilated in our system. All analyses are verified against the Joint Typhoon Warning Center Best Track data set. The errors are calculated for the position and intensity of the TCs. The global component of the ensemble-based system shows improvement in po- sition analysis over the NCEP Reanalysis, but shows no significant difference from the NCEP operational analysis for most of the storm tracks. The regional com- ponent of our system improves position analysis over all the global analyses. The intensity analyses, measured by the minimum sea level pressure, are of similar quality in all of the analyses. Regional deterministic forecasts started from our analyses are generally not significantly different from those started from the GFS operational analysis. On average, the regional experiments performed better for longer than 48 h sea level pressure forecasts, while the global forecast performed better in predicting the position for longer than 48 h.

Education Reform in Botswana: Reflections on Policy Contradictions and Paradoxes

ERIC Educational Resources Information Center

Tabulawa, Richard Tjombe

2009-01-01

Literature on globalisation claims that changed global patterns of production and industrial organisation have intensified international economic competition, prompting nations globally to restructure their education systems in an attempt to position themselves favourably in an increasingly competitive economic environment. This is an environment…

Building resilience of the Global Positioning System to space weather

NASA Astrophysics Data System (ADS)

Fisher, Genene; Kunches, Joseph

2011-12-01

Almost every aspect of the global economy now depends on GPS. Worldwide, nations are working to create a robust Global Navigation Satellite System (GNSS), which will provide global positioning, navigation, and timing (PNT) services for applications such as aviation, electric power distribution, financial exchange, maritime navigation, and emergency management. The U.S. government is examining the vulnerabilities of GPS, and it is well known that space weather events, such as geomagnetic storms, contribute to errors in single-frequency GPS and are a significant factor for differential GPS. The GPS industry has lately begun to recognize that total electron content (TEC) signal delays, ionospheric scintillation, and solar radio bursts can also interfere with daily operations and that these threats grow with the approach of the next solar maximum, expected to occur in 2013. The key challenges raised by these circumstances are, first, to better understand the vulnerability of GPS technologies and services to space weather and, second, to develop policies that will build resilience and mitigate risk.

Determination of Earth orientation using the Global Positioning System

NASA Technical Reports Server (NTRS)

Freedman, A. P.

1989-01-01

Modern spacecraft tracking and navigation require highly accurate Earth-orientation parameters. For near-real-time applications, errors in these quantities and their extrapolated values are a significant error source. A globally distributed network of high-precision receivers observing the full Global Positioning System (GPS) configuration of 18 or more satellites may be an efficient and economical method for the rapid determination of short-term variations in Earth orientation. A covariance analysis using the JPL Orbit Analysis and Simulation Software (OASIS) was performed to evaluate the errors associated with GPS measurements of Earth orientation. These GPS measurements appear to be highly competitive with those from other techniques and can potentially yield frequent and reliable centimeter-level Earth-orientation information while simultaneously allowing the oversubscribed Deep Space Network (DSN) antennas to be used more for direct project support.

Precise orbit determination for NASA's earth observing system using GPS (Global Positioning System)

NASA Technical Reports Server (NTRS)

Williams, B. G.

1988-01-01

An application of a precision orbit determination technique for NASA's Earth Observing System (EOS) using the Global Positioning System (GPS) is described. This technique allows the geometric information from measurements of GPS carrier phase and P-code pseudo-range to be exploited while minimizing requirements for precision dynamical modeling. The method combines geometric and dynamic information to determine the spacecraft trajectory; the weight on the dynamic information is controlled by adjusting fictitious spacecraft accelerations in three dimensions which are treated as first order exponentially time correlated stochastic processes. By varying the time correlation and uncertainty of the stochastic accelerations, the technique can range from purely geometric to purely dynamic. Performance estimates for this technique as applied to the orbit geometry planned for the EOS platforms indicate that decimeter accuracies for EOS orbit position may be obtainable. The sensitivity of the predicted orbit uncertainties to model errors for station locations, nongravitational platform accelerations, and Earth gravity is also presented.

Vector Observation-Aided/Attitude-Rate Estimation Using Global Positioning System Signals

NASA Technical Reports Server (NTRS)

Oshman, Yaakov; Markley, F. Landis

1997-01-01

A sequential filtering algorithm is presented for attitude and attitude-rate estimation from Global Positioning System (GPS) differential carrier phase measurements. A third-order, minimal-parameter method for solving the attitude matrix kinematic equation is used to parameterize the filter's state, which renders the resulting estimator computationally efficient. Borrowing from tracking theory concepts, the angular acceleration is modeled as an exponentially autocorrelated stochastic process, thus avoiding the use of the uncertain spacecraft dynamic model. The new formulation facilitates the use of aiding vector observations in a unified filtering algorithm, which can enhance the method's robustness and accuracy. Numerical examples are used to demonstrate the performance of the method.

Improved treatment of global positioning system force parameters in precise orbit determination applications

NASA Technical Reports Server (NTRS)

Vigue, Y.; Lichten, S. M.; Muellerschoen, R. J.; Blewitt, G.; Heflin, M. B.

1993-01-01

Data collected from a worldwide 1992 experiment were processed at JPL to determine precise orbits for the satellites of the Global Positioning System (GPS). A filtering technique was tested to improve modeling of solar-radiation pressure force parameters for GPS satellites. The new approach improves orbit quality for eclipsing satellites by a factor of two, with typical results in the 25- to 50-cm range. The resultant GPS-based estimates for geocentric coordinates of the tracking sites, which include the three DSN sites, are accurate to 2 to 8 cm, roughly equivalent to 3 to 10 nrad of angular measure.

GPS meteorology - Remote sensing of atmospheric water vapor using the Global Positioning System

NASA Technical Reports Server (NTRS)

Bevis, Michael; Businger, Steven; Herring, Thomas A.; Rocken, Christian; Anthes, Richard A.; Ware, Randolph H.

1992-01-01

We present a new approach to remote sensing of water vapor based on the Global Positioning System (GPS). Geodesists and geophysicists have devised methods for estimating the extent to which signals propagating from GPS satellites to ground-based GPS receivers are delayed by atmospheric water vapor. This delay is parameterized in terms of a time-varying zenith wet delay (ZWD) which is retrieved by stochastic filtering of the GPS data. Given surface temperature and pressure readings at the GPS receiver, the retrieved ZWD can be transformed with very little additional uncertainty into an estimate of the integrated water vapor (IWV) overlying that receiver. Networks of continuously operating GPS receivers are being constructed by geodesists, geophysicists, and government and military agencies, in order to implement a wide range of positioning capabilities. These emerging GPS networks offer the possibility of observing the horizontal distribution of IWV or, equivalently, precipitate water with unprecedented coverage and a temporal resolution of the order of 10 min. These measurements could be utilized in operational weather forecasting and in fundamental research into atmospheric storm systems, the hydrologic cycle, atmospheric chemistry, and global climate change.

Modular Software for Spacecraft Navigation Using the Global Positioning System (GPS)

NASA Technical Reports Server (NTRS)

Truong, S. H.; Hartman, K. R.; Weidow, D. A.; Berry, D. L.; Oza, D. H.; Long, A. C.; Joyce, E.; Steger, W. L.

1996-01-01

The Goddard Space Flight Center Flight Dynamics and Mission Operations Divisions have jointly investigated the feasibility of engineering modular Global Positioning SYSTEM (GPS) navigation software to support both real time flight and ground postprocessing configurations. The goals of this effort are to define standard GPS data interfaces and to engineer standard, reusable navigation software components that can be used to build a broad range of GPS navigation support applications. The paper discusses the GPS modular software (GMOD) system and operations concepts, major requirements, candidate software architecture, feasibility assessment and recommended software interface standards. In additon, ongoing efforts to broaden the scope of the initial study and to develop modular software to support autonomous navigation using GPS are addressed,

The Effect of Global and Local Damping on the Perception of Hardness.

PubMed

van Beek, Femke Elise; Heck, Dennis J F; Nijmeijer, Henk; Bergmann Tiest, Wouter M; Kappers, Astrid M L

2016-01-01

In tele-operation systems, damping is often injected to guarantee system stability during contact with hard objects. In this study, we used psychophysical experiments to assess the effect of adding damping on the user's perception of object hardness. In Experiments 1 and 2, combinations of stiffness and damping were tested to assess their effect on perceived hardness. In both experiments, two tasks were used: an in-contact task, starting at the object's surface, and a contact-transition task, including a free-air movement. In Experiment 3, the difference between inserting damping globally (equally throughout the workspace) and locally (inside the object only) was tested. In all experiments, the correlation between the participant's perceptual decision and force and position data was also investigated. Experiments 1 and 2 show that when injecting damping globally, perceived hardness slightly increased for an in-contact task, while it decreased considerably for a contact-transition task. Experiment 3 shows that this effect was mainly due to inserting damping globally, since there was a large perceptual difference between inserting damping globally and locally. The force and position parameters suggest that participants used the same force profile during the two movements of one trial and assessed the system's reaction to this force to perceive hardness.

BDS/GPS Dual Systems Positioning Based on the Modified SR-UKF Algorithm

PubMed Central

Kong, JaeHyok; Mao, Xuchu; Li, Shaoyuan

2016-01-01

The Global Navigation Satellite System can provide all-day three-dimensional position and speed information. Currently, only using the single navigation system cannot satisfy the requirements of the system’s reliability and integrity. In order to improve the reliability and stability of the satellite navigation system, the positioning method by BDS and GPS navigation system is presented, the measurement model and the state model are described. Furthermore, the modified square-root Unscented Kalman Filter (SR-UKF) algorithm is employed in BDS and GPS conditions, and analysis of single system/multi-system positioning has been carried out, respectively. The experimental results are compared with the traditional estimation results, which show that the proposed method can perform highly-precise positioning. Especially when the number of satellites is not adequate enough, the proposed method combine BDS and GPS systems to achieve a higher positioning precision. PMID:27153068

33 CFR 401.20 - Automatic Identification System.

Code of Federal Regulations, 2010 CFR

2010-07-01

...' maritime Differential Global Positioning System radiobeacon services; or (7) The use of a temporary unit... Identification System. (a) Each of the following vessels must use an Automatic Identification System (AIS... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Automatic Identification System...

Negative health system effects of Global Fund's investments in AIDS, tuberculosis and malaria from 2002 to 2009: systematic review.

PubMed

Car, Josip; Paljärvi, Tapio; Car, Mate; Kazeem, Ayodele; Majeed, Azeem; Atun, Rifat

2012-10-01

By using the Global Fund as a case example, we aim to critically evaluate the evidence generated from 2002 to 2009 for potential negative health system effects of Global Health Initiatives (GHI). Systematic review of research literature. Developing Countries. All interventions potentially affecting health systems that were funded by the Global Fund. Negative health system effects of Global Fund investments as reported by study authors. We identified 24 studies commenting on adverse effects on health systems arising from Global Fund investments. Sixteen were quantitative studies, six were qualitative and two used both quantitative and qualitative methods, but none explicitly stated that the studies were originally designed to capture or to assess health system effects (positive or negative). Only seemingly anecdotal evidence or authors' perceptions/interpretations of circumstances could be extracted from the included studies. This study shows that much of the currently available evidence generated between 2002 and 2009 on GHIs potential negative health system effects is not of the quality expected or needed to best serve the academic or broader community. The majority of the reviewed research did not fulfil the requirements of rigorous scientific evidence.

Emergency information systems for cars

NASA Astrophysics Data System (ADS)

Thirunavukkarasu, M.; Vani Manasa, N.; Kumar, K. Rajesh; Sundar, S.

2017-11-01

The main objective of this work is to create a Health Care monitoring and Guidance system for persons who are travelling in outdoor environments like cars. GSM (Global System for Mobile Communications) and GPS (Global Positioning System) technologies are separately and combined today in many applications in our day to day life. The GSM module will send a message along with the GPS location to the end user through text, and a call is initiated to the user for further instructions. The Global Positioning System (GPS) will give the location of the interested vehicle. This system helps the doctor or anyone to monitor the accident who is outdoor and has less help. This will help the hospital to monitor the accident as well as guide the injured through difficult situations. Using a buzzer, the persons nearby will come to know that the person is in danger or in poor health conditions. This project provides a good two-way communication with the injured and the hospital to assist them to give first aid before an ambulance arrives. So, this paper devices a novel technique to assist the people who just met with accident through GPS and GSM.

Local and global stability for Lotka-Volterra systems with distributed delays and instantaneous negative feedbacks

NASA Astrophysics Data System (ADS)

Faria, Teresa; Oliveira, José J.

This paper addresses the local and global stability of n-dimensional Lotka-Volterra systems with distributed delays and instantaneous negative feedbacks. Necessary and sufficient conditions for local stability independent of the choice of the delay functions are given, by imposing a weak nondelayed diagonal dominance which cancels the delayed competition effect. The global asymptotic stability of positive equilibria is established under conditions slightly stronger than the ones required for the linear stability. For the case of monotone interactions, however, sharper conditions are presented. This paper generalizes known results for discrete delays to systems with distributed delays. Several applications illustrate the results.

Implementing GPS into Pave-IR.

DOT National Transportation Integrated Search

2009-03-01

To further enhance the capabilities of the Pave-IR thermal segregation detection system developed at the Texas Transportation Institute, researchers incorporated global positioning system (GPS) data collection into the thermal profiles. This GPS capa...

GPS system simulation methodology

NASA Technical Reports Server (NTRS)

Ewing, Thomas F.

1993-01-01

The following topics are presented: background; Global Positioning System (GPS) methodology overview; the graphical user interface (GUI); current models; application to space nuclear power/propulsion; and interfacing requirements. The discussion is presented in vugraph form.

Development of a congestion management system using GPS technology

DOT National Transportation Integrated Search

1997-04-01

This report describes the results of a study undertaken to demonstrate the feasibility of using global positioning system (GPS) and geographic information system (GIS) technologies to measure travel time and speed data on urban highways. The methodol...

Mapping invasive weeds and their control with spatial information technologies

USDA-ARS?s Scientific Manuscript database

We discuss applications of airborne multispectral digital imaging systems, imaging processing techniques, global positioning systems (GPS), and geographic information systems (GIS) for mapping the invasive weeds giant salvinia (Salvinia molesta) and Brazilian pepper (Schinus terebinthifolius) and fo...

Computer-aided system for detecting runway incursions

NASA Astrophysics Data System (ADS)

Sridhar, Banavar; Chatterji, Gano B.

1994-07-01

A synthetic vision system for enhancing the pilot's ability to navigate and control the aircraft on the ground is described. The system uses the onboard airport database and images acquired by external sensors. Additional navigation information needed by the system is provided by the Inertial Navigation System and the Global Positioning System. The various functions of the system, such as image enhancement, map generation, obstacle detection, collision avoidance, guidance, etc., are identified. The available technologies, some of which were developed at NASA, that are applicable to the aircraft ground navigation problem are noted. Example images of a truck crossing the runway while the aircraft flies close to the runway centerline are described. These images are from a sequence of images acquired during one of the several flight experiments conducted by NASA to acquire data to be used for the development and verification of the synthetic vision concepts. These experiments provide a realistic database including video and infrared images, motion states from the Inertial Navigation System and the Global Positioning System, and camera parameters.

Satellite Navigation Systems: Policy, Commercial and Technical Interaction.

NASA Astrophysics Data System (ADS)

Rycroft, M.

2003-12-01

This book adopts a broad perspective on positioning and navigation systems which rely on Earth orbiting satellites for their successful operation. The first of such global systems was the US Global Positioning System (GPS), and the next the Russian GLONASS system. Now studies relating to Europe's future Galileo system are gaining momentum and other nations are planning regional augmentation systems. All such systems are discussed here, particularly relating to political, commercial, legal and technical issues. The opportunities - and also the problems - of having three similar systems in operation simultaneously are examined, and several novel applications are proposed. These range from improved vehicular transport by land, sea and air, to more accurate surveying, more efficient agricultural practices and safer operations in mountainous regions. Everyone who is challenged by these topics will find this volume invaluable. ISU WWW Server; http://www.isunet.edu. Further information on ISU Symposia may also be obtained by e-mail from symposium@isu.isunet.edu Link: http://www.wkap.nl/prod/b/1-4020-1678-6

Home in the heat: Dramatic seasonal variation in home range of desert golden eagles informs management for renewable energy development

Treesearch

Melissa Braham; Tricia Miller; Adam E. Duerr; Michael Lanzone; Amy Fesnock; Larry LaPre; Daniel Driscoll; Todd Katzner

2015-01-01

Renewable energy is expanding quickly with sometimes dramatic impacts to species and ecosystems. To understand the degree to which sensitive species may be impacted by renewable energy projects, it is informative to know how much space individuals use and how that space may overlap with planned development. We used global positioning system-global system for mobile...

Advances in structural monitoring with Global Positioning System technology: 1997-2006

NASA Astrophysics Data System (ADS)

Ogaja, Clement; Li, Xiaojing; Rizos, Chris

2007-11-01

Over the last decade, users of the Global Positioning System (GPS) have developed the technology capable of meeting stringent requirements to study the dynamics of tall buildings, towers, and bridges during earthquakes, wind-induced deformation and traffic loading. Dynamic measurements of relative displacements of structures is currently possible using real-time kinematic (RTK) positioning techniques, now advanced to record typically at 10-20 Hz (or higher - e.g., 100 Hz) with an accuracy of ±1 cm horizontally and ±2 cm vertically. With further advances in the technology and improvements in sampling capability, it is possible to meet the needs of real-time displacement information for the structural engineering community. After a decade of great strides in proving the feasibility of the technology, focus is moving to sensor integration and operational systems. Several investigators are now routinely researching the integration of GPS with other sensors (accelerometers, fibre optics, pseudolites, etc.) to utilise the complementary benefits and overcome limitations of the individual systems. Examples of real-time operational systems exist to demonstrate the significance of GPS technology in measuring the dynamic behaviour of large engineering structures.

Radionavigation systems : a capabilities investment strategy.

DOT National Transportation Integrated Search

2004-01-01

The Final Report of the President's Commission on Critical Infrastructure Protection concluded that Global Positioning System (GPS) services and applications are susceptible to various types of interference, and that the effects of these vulnerabilit...

Evaluation of Emerging Technologies for Traffic Crash Reporting

DOT National Transportation Integrated Search

1998-02-01

An evaluation was performed of the effect of emerging technologies on traffic accident reporting. The technologies evaluated were standard laptop and pen-based portable computers, Global Positioning Systems (GPS), Geographic Information Systems (GIS)...

33 CFR 3.01-1 - General description.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Administration (NOAA) using the NAD 1983 coordinate system and projected to the WGS 1984 grid system. Both coordinate systems are geocentric and similar such that they are Global Positioning System (GPS) compatible... based upon boundaries and points located using the WGS 1984 world grid system. When referenced, the...

Procedures for woody vegetation surveys in the Kazgail rural council area, Kordofan, Sudan

USGS Publications Warehouse

Falconer, Allan; Cross, Matthew D.; Orr, Donald G.

1990-01-01

Efforts to reforest parts of the Kordofan Province of Sudan are receiving support from international development agencies. These efforts include planning and implementing reforestation activities that require the collection of natural resources and socioeconomic data, and the preparation of base maps. A combination of remote sensing, geographic information system and global positioning systems procedures are used in this study to meet these requirements.Remote sensing techniques were used to provide base maps and to guide the compilation of vegetation resources maps. These techniques provided a rapid and efficient method for documenting available resources. Pocket‐sized global positioning system units were used to establish the location of field data collected for mapping and resource analysis. A microcomputer data management system tabulated and displayed the field data. The resulting system for data analysis, management, and planning has been adopted for the mapping and inventory of the Gum Belt of Sudan.

Using GPS To Teach More Than Accurate Positions.

ERIC Educational Resources Information Center

Johnson, Marie C.; Guth, Peter L.

2002-01-01

Undergraduate science majors need practice in critical thinking, quantitative analysis, and judging whether their calculated answers are physically reasonable. Develops exercises using handheld Global Positioning System (GPS) receivers. Reinforces students' abilities to think quantitatively, make realistic "back of the envelope"…

78 FR 22554 - Nationwide Differential Global Positioning System (NDGPS)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-16

... developed by the Coast Guard in the 1990s to improve GPS-calculated positions for navigation, for positioning aids to navigation, in support of maritime safety requirements and to offset the error induced by..., maintain, and operate such aids to navigation is found in 14 U.S.C. 81. \\1\\ Initially, high quality GPS...

Memorandum of Agreement Between the Department of Defense and the Department of Transportation : Civil Use of the Global Positioning System

DOT National Transportation Integrated Search

2008-01-01

This Memorandum of Agreement (MOA) establishes policies and procedures to ensure an effective working relationship between the Department of Defense (DoD) and the Department of Transportation (DOT) regarding civil use of the Navstar Global Positionin...

Variations of total electron content during geomagnetic disturbances: A model/observation comparison

NASA Technical Reports Server (NTRS)

Roble, G. Lu X. Pi A. D. Richmond R. G.

1997-01-01

This paper studies the ionospheric response to major geomagnetic storm of October 18-19, 1995, using the thermosphere-ionosphere electrodynamic general circulation model (TIE-GCM) simulations and the global ionospheric maps (GIM) of total electron content (TEC) observations from the Global Positioning System (GPS) worldwide network.

The Flattening of Literacy: Community Colleges and Skills Training

ERIC Educational Resources Information Center

Pennell, Michael

2011-01-01

Community colleges occupy a contradictory position in the rise of globalization. They are at once both local and global institutions. This essay examines the complicated location of community colleges in local economies through the developing community college system in Indiana. In particular, it highlights the horizontal transitions of a growing…

A Recommendation on SLR Ranging to Future Global Navigation Satellite Systems

NASA Astrophysics Data System (ADS)

Labrecque, J. L.; Miller, J. J.; Pearlman, M.

2008-12-01

The multi-agency US Geodetic Requirements Working Group has recommended that Satellite Laser Retro- reflectors be installed on GPS III satellites as a principal component of the Positioning, Navigation, and Timing mandate of the Global Positioning System. The Working Group, which includes NASA, NGA, NOAA, NRL, USGS, and the USNO, echoes the Global Geodetic Observing System recommendation that SLR retro- reflectors be installed on all GNSS satellites. It is further recommended that the retro-reflectors conform to and hopefully exceed the minimum standard of the International Laser Ranging Service for retro-reflector cross sections of 100 million square meters for the HEO GNSS satellites to insure sufficiently accurate ranging by the global network of satellite laser ranging systems. The objective of this recommendation is to contribute to the improvement in the International Terrestrial Reference Frame, and its derivative the WGS84 reference frame, through continuing improvements in the characterization of the GPS orbits and clocks. Another objective is to provide an independent means of assessing the interoperability and accuracy of the GNSS systems and regional augmentation systems. The ranging to GNSS-mounted retro-reflectors will constitute a significant new means of space-based collocation to constrain the tie between the GPS and SLR networks that constitute over 50% of the data from which the ITRF is derived. The recommendation for the installation of SLR retro-reflectors aboard future GPS satellites is one of a number of efforts aimed at improving the accuracy and stability of ITRF. These steps are being coordinated with and supportive of the efforts of the GGOS and its services such at the VLBI2010 initiative, developing a next generation geodetic network, near real-time GPS positioning and EOP determination, and numerous efforts in the improvement of geodetic algorithms for GPS, SLR, VLBI, DORIS, and the determination of the ITRF. If past is prologue, the requirements of accuracy placed upon GNSS systems will continue to evolve at a factor of ten per decade for the lifetime of the GPS III, extending to 2025 and beyond. Global societal priorities such as sea level change measurement already require a factor of ten or more improvement in the accuracy and stability of the ITRF. Increasing accuracy requirements by civilian users for precision positioning and time keeping will certainly continue to grow at an exponential rate. The PNT accuracy of our GNSS systems will keep pace with these societal needs only if we equip the GNSS systems with the capability to identify and further reduce systematic errors.

Analysis of continuous GPS measurements from southern Victoria Land, Antarctica

USGS Publications Warehouse

Willis, Michael J.

2007-01-01

Several years of continuous data have been collected at remote bedrock Global Positioning System (GPS) sites in southern Victoria Land, Antarctica. Annual to sub-annual variations are observed in the position time-series. An atmospheric pressure loading (APL) effect is calculated from pressure field anomalies supplied by the European Centre for Medium-Range Weather Forecasts (ECMWF) model loading an elastic Earth model. The predicted APL signal has a moderate correlation with the vertical position time-series at McMurdo, Ross Island (International Global Navigation Satellite System Service (IGS) station MCM4), produced using a global solution. In contrast, a local solution in which MCM4 is the fiducial site generates a vertical time series for a remote site in Victoria Land (Cape Roberts, ROB4) which exhibits a low, inverse correlation with the predicted atmospheric pressure loading signal. If, in the future, known and well modeled geophysical loads can be separated from the time-series, then local hydrological loading, of interest for glaciological and climate applications, can potentially be extracted from the GPS time-series.

Dynamics and profiles of a diffusive host-pathogen system with distinct dispersal rates

NASA Astrophysics Data System (ADS)

Wu, Yixiang; Zou, Xingfu

2018-04-01

In this paper, we investigate a diffusive host-pathogen model with heterogeneous parameters and distinct dispersal rates for the susceptible and infected hosts. We first prove that the solution of the model exists globally and the model system possesses a global attractor. We then identify the basic reproduction number R0 for the model and prove its threshold role: if R0 ≤ 1, the disease free equilibrium is globally asymptotically stable; if R0 > 1, the solution of the model is uniformly persistent and there exists a positive (pathogen persistent) steady state. Finally, we study the asymptotic profiles of the positive steady state as the dispersal rate of the susceptible or infected hosts approaches zero. Our result suggests that the infected hosts concentrate at certain points which can be characterized as the pathogen's most favoured sites when the mobility of the infected host is limited.

Precise tracking of remote sensing satellites with the Global Positioning System

NASA Technical Reports Server (NTRS)

Yunck, Thomas P.; Wu, Sien-Chong; Wu, Jiun-Tsong; Thornton, Catherine L.

1990-01-01

The Global Positioning System (GPS) can be applied in a number of ways to track remote sensing satellites at altitudes below 3000 km with accuracies of better than 10 cm. All techniques use a precise global network of GPS ground receivers operating in concert with a receiver aboard the user satellite, and all estimate the user orbit, GPS orbits, and selected ground locations simultaneously. The GPS orbit solutions are always dynamic, relying on the laws of motion, while the user orbit solution can range from purely dynamic to purely kinematic (geometric). Two variations show considerable promise. The first one features an optimal synthesis of dynamics and kinematics in the user solution, while the second introduces a novel gravity model adjustment technique to exploit data from repeat ground tracks. These techniques, to be demonstrated on the Topex/Poseidon mission in 1992, will offer subdecimeter tracking accuracy for dynamically unpredictable satellites down to the lowest orbital altitudes.

Navigation studies based on the ubiquitous positioning technologies

NASA Astrophysics Data System (ADS)

Ye, Lei; Mi, Weijie; Wang, Defeng

2007-11-01

This paper summarized the nowadays positioning technologies, such as absolute positioning methods and relative positioning methods, indoor positioning and outdoor positioning, active positioning and passive positioning. Global Navigation Satellite System (GNSS) technologies were introduced as the omnipresent out-door positioning technologies, including GPS, GLONASS, Galileo and BD-1/2. After analysis of the shortcomings of GNSS, indoor positioning technologies were discussed and compared, including A-GPS, Cellular network, Infrared, Electromagnetism, Computer Vision Cognition, Embedded Pressure Sensor, Ultrasonic, RFID (Radio Frequency IDentification), Bluetooth, WLAN etc.. Then the concept and characteristics of Ubiquitous Positioning was proposed. After the ubiquitous positioning technologies contrast and selection followed by system engineering methodology, a navigation system model based on Incorporate Indoor-Outdoor Positioning Solution was proposed. And this model was simulated in the Galileo Demonstration for World Expo Shanghai project. In the conclusion, the prospects of ubiquitous positioning based navigation were shown, especially to satisfy the public location information acquiring requirement.

Development of a congestion management system using GPS technology : technical summary.

DOT National Transportation Integrated Search

1996-11-01

The overall goal of this research study was to demonstrate the feasibility of using global positioning system (GPS) and geographic information system (GIS) technologies to measure travel time and speed data on urban highways.Compared to more traditio...

Improved Navigational Technology and Air Traffic Control: A Description of Controller Coordination and Workload

DOT National Transportation Integrated Search

1995-04-01

Improved navigational technology, such as microwave landing systems (MLS) or : global positioning systems (GPS), installed in today's commercial aircraft : enable the air traffic control (ATC) system to better utilize its airspace. : This increased e...

76 FR 45478 - Proposed Establishment of Class E Airspace; Nahunta, GA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-29

...) Global Positioning System (GPS) Standard Instrument Approach Procedures serving the Brantley County...) operations within the National Airspace System. DATES: Comments must be received on or before September 12... distribution System, which describes the application procedure. [[Page 45479

Development of a congestion management system using GPS technology : volume I.

DOT National Transportation Integrated Search

1997-04-01

This report describes the results of a study undertaken to demonstrate the feasibility of using global positioning system( GPS) and geographic information system (CIS) technologies to measure travel time and speed data on urban highways. Compared to ...

Global Precipitation Patterns Associated with ENSO and Tropical Circulations

NASA Technical Reports Server (NTRS)

Curtis, Scott; Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric

1999-01-01

Tropical precipitation and the accompanying latent heat release is the engine that drives the global circulation. An increase or decrease in rainfall in the tropics not only leads to the local effects of flooding or drought, but contributes to changes in the large scale circulation and global climate system. Rainfall in the tropics is highly variable, both seasonally (monsoons) and interannually (ENSO). Two experimental observational data sets, developed under the auspices of the Global Precipitation Climatology Project (GPCP), are used in this study to examine the relationships between global precipitation and ENSO and extreme monsoon events over the past 20 years. The V2x79 monthly product is a globally complete, 2.5 deg x 2.5 deg, satellite-gauge merged data set that covers the period 1979 to the present. Indices based on patterns of satellite-derived rainfall anomalies in the Pacific are used to analyze the teleconnections between ENSO and global precipitation, with emphasis on the monsoon systems. It has been well documented that dry (wet) Asian monsoons accompany warm (cold) ENSO events. However, during the summer seasons of the 1997/98 ENSO the precipitation anomalies were mostly positive over India and the Bay of Bengal, which may be related to an epoch-scale variability in the Asian monsoon circulation. The North American monsoon may be less well linked to ENSO, but a positive precipitation anomaly was observed over Mexico around the September following the 1997/98 event. For the twenty-year record, precipitation and SST patterns in the tropics are analyzed during wet and dry monsoons. For the Asian summer monsoon, positive rainfall anomalies accompany two distinct patterns of tropical precipitation and a warm Indian Ocean. Negative anomalies coincide with a wet Maritime Continent.

Weather Information System

NASA Technical Reports Server (NTRS)

1995-01-01

WxLink is an aviation weather system based on advanced airborne sensors, precise positioning available from the satellite-based Global Positioning System, cockpit graphics and a low-cost datalink. It is a two-way system that uplinks weather information to the aircraft and downlinks automatic pilot reports of weather conditions aloft. Manufactured by ARNAV Systems, Inc., the original technology came from Langley Research Center's cockpit weather information system, CWIN (Cockpit Weather INformation). The system creates radar maps of storms, lightning and reports of surface observations, offering improved safety, better weather monitoring and substantial fuel savings.

The Global Positioning System

USGS Publications Warehouse

,

1999-01-01

The Global Positioning System (GPS) is a constellation of navigation satellites called Navigation Satellite Timing And Ranging (NAVSTAR), maintained by the U.S. Department of Defense. Many outdoor enthusiasts recognize that a handheld GPS receiver can be an accurate tool for determining their location on the terrain. The GPS receiver helps determine locations on the Earth's surface by collecting signals from three or more satellites through a process called triangulation. Identifying a location on the Earth is more useful if you also know about the surrounding topographic conditions. Using a topographic map with the GPS receiver provides important information about features of the surrounding terrain and can help you plot an effective route from one location to another.

The limits of direct satellite tracking with the Global Positioning System (GPS)

NASA Technical Reports Server (NTRS)

Bertiger, W. I.; Yunck, T. P.

1988-01-01

Recent advances in high precision differential Global Positioning System-based satellite tracking can be applied to the more conventional direct tracking of low earth satellites. To properly evaluate the limiting accuracy of direct GPS-based tracking, it is necessary to account for the correlations between the a-priori errors in GPS states, Y-bias, and solar pressure parameters. These can be obtained by careful analysis of the GPS orbit determination process. The analysis indicates that sub-meter accuracy can be readily achieved for a user above 1000 km altitude, even when the user solution is obtained with data taken 12 hours after the data used in the GPS orbit solutions.

Relative motions of the Australian, Pacific and Antarctic plates estimated by the Global Positioning System

NASA Technical Reports Server (NTRS)

Larson, Kristine M.; Freymueller, Jeff

1995-01-01

Global Positioning System (GPS) measurements spanning approximately 3 years have been used to determine velocities for 7 sites on the Australian, Pacific and Antarctic plates. The site velocities agree with both plate model predictions and other space geodetic techniques. We find no evidence for internal deformation of the interior of the Australian plate. Wellington, New Zealand, located in the Australian-Pacific plate boundary zone, moves 20 +/- 5 mm/yr west-southwest relative to the Australian plate. Its velocity lies midway between the predicted velocities of the two plates. Relative Euler vectors for the Australia-Antarctica and Pacific-Antarctica plates agree within one standard deviation with the NUVEL-1A predictions.

Problems with studying wolf predation on small prey in summer via global positioning system collars

USGS Publications Warehouse

Palacios, Vicente; Mech, L. David

2010-01-01

We attempted to study predation on various-sized prey by a male and female wolf (Canis lupus) with global positioning system (GPS) collars programmed to acquire locations every 10 min in the Superior National Forest of Minnesota. During May to August 2007, we investigated 147 clusters of locations (31% of the total) and found evidence of predation on a white-tailed deer (Odocoileus virginianus) fawn and yearling, a beaver (Castor canadensis), ruffed grouse (Bonasa umbellus), and fisher (Martes pennanti) and scavenging on a road-killed deer and other carrion. However, we missed finding many prey items and discuss the problems associated with trying to conduct such a study.

Problems with studying wolf predation on small prey in summer via global positioning system collars

USGS Publications Warehouse

Palacios, V.; Mech, L.D.

2011-01-01

We attempted to study predation on various-sized prey by a male and female wolf (Canis lupus) with global positioning system (GPS) collars programmed to acquire locations every 10 min in the Superior National Forest of Minnesota. During May to August 2007, we investigated 147 clusters of locations (31% of the total) and found evidence of predation on a white-tailed deer (Odocoileus virginianus) fawn and yearling, a beaver (Castor canadensis), ruffed grouse (Bonasa umbellus), and fisher (Martes pennanti) and scavenging on a road-killed deer and other carrion. However, we missed finding many prey items and discuss the problems associated with trying to conduct such a study. ?? 2010 US Government.

Global Positioning System Time Transfer Receiver (GPS/TTR) prototype design and initial test evaluation

NASA Technical Reports Server (NTRS)

Oaks, J.; Frank, A.; Falvey, S.; Lister, M.; Buisson, J.; Wardrip, C.; Warren, H.

1982-01-01

Time transfer equipment and techniques used with the Navigation Technology Satellites were modified and extended for use with the Global Positioning System (GPS) satellites. A prototype receiver was built and field tested. The receiver uses the GPS L1 link at 1575 MHz with C/A code only to resolve a measured range to the satellite. A theoretical range is computed from the satellite ephemeris transmitted in the data message and the user's coordinates. Results of user offset from GPS time are obtained by differencing the measured and theoretical ranges and applying calibration corrections. Results of the first field test evaluation of the receiver are presented.

Global low-energy weak solution and large-time behavior for the compressible flow of liquid crystals

NASA Astrophysics Data System (ADS)

Wu, Guochun; Tan, Zhong

2018-06-01

In this paper, we consider the weak solution of the simplified Ericksen-Leslie system modeling compressible nematic liquid crystal flows in R3. When the initial data are of small energy and initial density is positive and essentially bounded, we prove the existence of a global weak solution in R3. The large-time behavior of a global weak solution is also established.

Great expectations for the World Health Organization: a Framework Convention on Global Health to achieve universal health coverage.

PubMed

Ooms, G; Marten, R; Waris, A; Hammonds, R; Mulumba, M; Friedman, E A

2014-02-01

Establishing a reform agenda for the World Health Organization (WHO) requires understanding its role within the wider global health system and the purposes of that wider global health system. In this paper, the focus is on one particular purpose: achieving universal health coverage (UHC). The intention is to describe why achieving UHC requires something like a Framework Convention on Global Health (FCGH) that have been proposed elsewhere,(1) why WHO is in a unique position to usher in an FCGH, and what specific reforms would help enable WHO to assume this role. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

78 FR 25406 - Proposed Modification of Class E Airspace; Twin Falls, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-01

...) Global Positioning System (GPS) and the Instrument Landing System (ILS) or Localizer (LOC) standard... the earth. * * * * * ANM ID E5 Twin Falls, ID [Modified] Twin Falls Joslin Field-Magic Valley Regional...

Smart Device-Supported BDS/GNSS Real-Time Kinematic Positioning for Sub-Meter-Level Accuracy in Urban Location-Based Services.

PubMed

Wang, Liang; Li, Zishen; Zhao, Jiaojiao; Zhou, Kai; Wang, Zhiyu; Yuan, Hong

2016-12-21

Using mobile smart devices to provide urban location-based services (LBS) with sub-meter-level accuracy (around 0.5 m) is a major application field for future global navigation satellite system (GNSS) development. Real-time kinematic (RTK) positioning, which is a widely used GNSS-based positioning approach, can improve the accuracy from about 10-20 m (achieved by the standard positioning services) to about 3-5 cm based on the geodetic receivers. In using the smart devices to achieve positioning with sub-meter-level accuracy, a feasible solution of combining the low-cost GNSS module and the smart device is proposed in this work and a user-side GNSS RTK positioning software was developed from scratch based on the Android platform. Its real-time positioning performance was validated by BeiDou Navigation Satellite System/Global Positioning System (BDS/GPS) combined RTK positioning under the conditions of a static and kinematic (the velocity of the rover was 50-80 km/h) mode in a real urban environment with a SAMSUNG Galaxy A7 smartphone. The results show that the fixed-rates of ambiguity resolution (the proportion of epochs of ambiguities fixed) for BDS/GPS combined RTK in the static and kinematic tests were about 97% and 90%, respectively, and the average positioning accuracies (RMS) were better than 0.15 m (horizontal) and 0.25 m (vertical) for the static test, and 0.30 m (horizontal) and 0.45 m (vertical) for the kinematic test.

Design Document for Differential GPS Ground Reference Station Pseudorange Correction Generation Algorithm

DOT National Transportation Integrated Search

1986-12-01

The algorithms described in this report determine the differential corrections to be broadcast to users of the Global Positioning System (GPS) who require higher accuracy navigation or position information than the 30 to 100 meters that GPS normally ...

Position estimation of transceivers in communication networks

DOEpatents

Kent, Claudia A [Pleasanton, CA; Dowla, Farid [Castro Valley, CA

2008-06-03

This invention provides a system and method using wireless communication interfaces coupled with statistical processing of time-of-flight data to locate by position estimation unknown wireless receivers. Such an invention can be applied in sensor network applications, such as environmental monitoring of water in the soil or chemicals in the air where the position of the network nodes is deemed critical. Moreover, the present invention can be arranged to operate in areas where a Global Positioning System (GPS) is not available, such as inside buildings, caves, and tunnels.

IMU: inertial sensing of vertical CoM movement.

PubMed

Esser, Patrick; Dawes, Helen; Collett, Johnny; Howells, Ken

2009-07-22

The purpose of this study was to use a quaternion rotation matrix in combination with an integration approach to transform translatory accelerations of the centre of mass (CoM) from an inertial measurement unit (IMU) during walking, from the object system onto the global frame. Second, this paper utilises double integration to determine the relative change in position of the CoM from the vertical acceleration data. Five participants were tested in which an IMU, consisting of accelerometers, gyroscopes and magnetometers was attached on the lower spine estimated centre of mass. Participants were asked to walk three times through a calibrated volume at their self-selected walking speed. Synchronized data were collected by an IMU and an optical motion capture system (OMCS); both measured at 100 Hz. Accelerations of the IMU were transposed onto the global frame using a quaternion rotation matrix. Translatory acceleration, speed and relative change in position from the IMU were compared with the derived data from the OMCS. Peak acceleration in vertical axis showed no significant difference (p> or =0.05). Difference between peak and trough speed showed significant difference (p<0.05) but relative peak-trough position between the IMU and OMCS did not show any significant difference (p> or =0.05). These results indicate that quaternions, in combination with Simpsons rule integration, can be used in transforming translatory acceleration from the object frame to the global frame and therefore obtain relative change in position, thus offering a solution for using accelerometers in accurate global frame kinematic gait analyses.

Comparison of Three Wind Measuring Systems for Flight Test

NASA Technical Reports Server (NTRS)

Teets, Edward H., Jr.; Harvey, Philip O.

2000-01-01

A preliminary field test of the accuracy of wind velocity measurements obtained using global positioning system-tracked rawinsonde balloons has been performed. Wind comparisons have been conducted using global positioning system (GPS) and radio automatic theodolite sounder (RATS) rawinsondes and a high-precision range instrumentation radar-tracked reflector. Wind velocity differences between the GPS rawinsondes and the radar were significantly less than between the RATS rawinsondes and the radar. These limited test results indicate a root-mean-square wind velocity difference from 4.98 kn (2.56 m/sec) for the radar and RATS to 1.09 kn (0.56 m/sec) for the radar and GPS. Differences are influenced by user reporting requirements, data processing techniques, and the inherent tracking accuracies of the system. This brief field test indicates that the GPS sounding system tracking data are more precise than the RATS system. When high-resolution wind data are needed, use of GPS rawinsonde systems can reduce the burden on range radar operations.

Global solutions to a class of multi-species reaction-diffusion systems with cross-diffusions arising in population dynamics

NASA Astrophysics Data System (ADS)

Wen, Zijuan; Fu, Shengmao

2009-08-01

In this paper, an n-species strongly coupled cooperating diffusive system is considered in a bounded smooth domain, subject to homogeneous Neumann boundary conditions. Employing the method of energy estimates, we obtain some conditions on the diffusion matrix and inter-specific cooperatives to ensure the global existence and uniform boundedness of a nonnegative solution. The globally asymptotical stability of the constant positive steady state is also discussed. As a consequence, all the results hold true for multi-species Lotka-Volterra type competition model and prey-predator model.

Development of low-altitude remote sensing systems for crop production management

USDA-ARS?s Scientific Manuscript database

Precision agriculture accounts for within-field variability for targeted treatment rather than uniform treatment of an entire field. Precision agriculture is built on agricultural mechanization and state-of-the-art technologies of geographical information systems (GIS), global positioning systems (G...

Time determination for spacecraft users of the Navstar Global Positioning System /GPS/

NASA Technical Reports Server (NTRS)

Grenchik, T. J.; Fang, B. T.

1977-01-01

Global Positioning System (GPS) navigation is performed by time measurements. A description is presented of a two body model of spacecraft motion. Orbit determination is the process of inferring the position, velocity, and clock offset of the user from measurements made of the user motion in the Newtonian coordinate system. To illustrate the effect of clock errors and the accuracy with which the user spacecraft time and orbit may be determined, a low-earth-orbit spacecraft (Seasat) as tracked by six Phase I GPS space vehicles is considered. The obtained results indicate that in the absence of unmodeled dynamic parameter errors clock biases may be determined to the nanosecond level. There is, however, a high correlation between the clock bias and the uncertainty in the gravitational parameter GM, i.e., the product of the universal gravitational constant and the total mass of the earth. It is, therefore, not possible to determine clock bias to better than 25 nanosecond accuracy in the presence of a gravitational error of one part per million.

The Global Positioning System: a high-tech success story

NASA Astrophysics Data System (ADS)

Ashby, Neil

2002-03-01

The Global Positioning System (GPS) consists of 24 or more satellites in twelve-hour orbits, each carrying atomic clocks and transmitting synchronized time and position information. The satellite system is supported by time referencing and processing centers, and data collection stations around the world. The signals make possible accurate navigation anywhere in the vicinity of Earth. There is probably no other large engineering system that relies on a broader range of applications of fundamental modern physics, such as special and general relativity, and atomic physics. Atomic clocks only a few inches on a side have been developed to an almost incredible stage of reliability and stability. Modern circuit fabrication techniques produce GPS receivers on a chip at cost comparable to that of handheld cell phones. Widespread availability and low cost in the civilian sector has led to a host of interesting applications. The economic impact of GPS is in the billions of dollars annually and is increasing. A comparable system, currently with only a few satellites, is the Soviet GLONASS. Europeans are developing another competitor, GALILEO, and have plans to place Hydrogen masers in space. These systems are changing the way we determine where we are and are revolutionizing many fields of scientific research.

Next Generation Vehicle Positioning and Simulation Solutions : Using GPS and Advanced Simulation Tools to Improve Highway Safety

DOT National Transportation Integrated Search

2013-06-03

"Integrated Global Positioning System and Inertial Navigation Unit (GPS/INU) Simulator for Enhanced Traffic Safety," is a project awarded to Ohio State University to integrate different simulation models to accurately study the relationship between v...

Global Positioning System data collection, processing, and analysis conducted by the U.S. Geological Survey Earthquake Hazards Program

USGS Publications Warehouse

Murray, Jessica R.; Svarc, Jerry L.

2017-01-01

The U.S. Geological Survey Earthquake Science Center collects and processes Global Positioning System (GPS) data throughout the western United States to measure crustal deformation related to earthquakes and tectonic processes as part of a long‐term program of research and monitoring. Here, we outline data collection procedures and present the GPS dataset built through repeated temporary deployments since 1992. This dataset consists of observations at ∼1950 locations. In addition, this article details our data processing and analysis procedures, which consist of the following. We process the raw data collected through temporary deployments, in addition to data from continuously operating western U.S. GPS stations operated by multiple agencies, using the GIPSY software package to obtain position time series. Subsequently, we align the positions to a common reference frame, determine the optimal parameters for a temporally correlated noise model, and apply this noise model when carrying out time‐series analysis to derive deformation measures, including constant interseismic velocities, coseismic offsets, and transient postseismic motion.

A magnetospheric signature of some F layer positive storms

NASA Technical Reports Server (NTRS)

Miller, N. J.; Mayr, H. G.; Grebowsky, J. M.; Harris, I.; Tulunay, Y. K.

1981-01-01

Calculations of electron density distributions in the global thermosphere-ionosphere system perturbed by high-latitude thermospheric heating are presented which indicate a link between the heating and magnetospheric plasma disturbances near the equator. The calculations were made using a self-consistent model of the global sunlit thermosphere-ionosphere system describing the evolution of equatorial plasma disturbances. The heat input is found to cause electron density enhancements that propagate along magnetic field lines from the F2 maximum over mid-latitudes to the equator in the magnetosphere and which correspond to the positive phase of an F layer storm. The positive phase is shown to be generated by the induction of equatorward winds that raise the mid-latitude F layer through momentum transfer from neutral atoms to ionospheric ions, which ions pull electrons with them. Model results are used to identify plasma signatures of equatorward winds and an intensified magnetospheric electric field in Explorer 45 and Arial 4 measurements taken during the positive phase of an F layer storm.

Use of micro unmanned aerial vehicles for roadside condition assessment

DOT National Transportation Integrated Search

2010-12-01

Micro unmanned aerial vehicles (MUAVs) that are equipped with digital imaging systems and global : positioning systems provide a potential opportunity for improving the effectiveness and safety of roadside : condition and inventory surveys. This stud...

PAVECHECK : integrating deflection and GPR for network condition surveys.

DOT National Transportation Integrated Search

2009-01-01

The PAVECHECK data integration and analysis system was developed to merge Falling Weight : Deflectometer (FWD) and Ground Penetrating Radar (GPR) data together with digital video images of : surface conditions. In this study Global Positioning System...

Global positioning systems for personal travel surveys : Lexington area travel data collection test

DOT National Transportation Integrated Search

1986-12-01

The urban transportation planning process is undergoing critical transformations. Of particular interest is the emergence of private sector involvement in the planning, management, financing, construction of transportation systems and provision of tr...

Simulation and analysis of differential global positioning system for civil helicopter operations

NASA Technical Reports Server (NTRS)

Denaro, R. P.; Cabak, A. R.

1983-01-01

A Differential Global Positioning System (DGPS) computer simulation was developed, to provide a versatile tool for assessing DGPS referenced civil helicopter navigation. The civil helicopter community will probably be an early user of the GPS capability because of the unique mission requirements which include offshore exploration and low altitude transport into remote areas not currently served by ground based Navaids. The Monte Carlo simulation provided a sufficiently high fidelity dynamic motion and propagation environment to enable accurate comparisons of alternative differential GPS implementations and navigation filter tradeoffs. The analyst has provided the capability to adjust most aspects of the system, the helicopter flight profile, the receiver Kalman filter, and the signal propagation environment to assess differential GPS performance and parameter sensitivities. Preliminary analysis was conducted to evaluate alternative implementations of the differential navigation algorithm in both the position and measurement domain. Results are presented to show that significant performance gains are achieved when compared with conventional GPS but that differences due to DGPS implementation techniques were small. System performance was relatively insensitive to the update rates of the error correction information.

Workshop Builds Strategies to Address Global Positioning System Vulnerabilities

NASA Astrophysics Data System (ADS)

Fisher, Genene

2011-01-01

When we examine the impacts of space weather on society, do we really understand the risks? Can past experiences reliably predict what will happen in the future? As the complexity of technology increases, there is the potential for it to become more fragile, allowing for a single point of failure to bring down the entire system. Take the Global Positioning System (GPS) as an example. GPS positioning, navigation, and timing have become an integral part of daily life, supporting transportation and communications systems vital to the aviation, merchant marine, cargo, cellular phone, surveying, and oil exploration industries. Everyday activities such as banking, mobile phone operations, and even the control of power grids are facilitated by the accurate timing provided by GPS. Understanding the risks of space weather to GPS and the many economic sectors reliant upon it, as well as how to build resilience, was the focus of a policy workshop organized by the American Meteorological Society (AMS) and held on 13-14 October 2010 in Washington, D. C. The workshop brought together a select group of policy makers, space weather scientists, and GPS experts and users.

Accurate Realization of GPS Vertical Global Reference Frame

NASA Technical Reports Server (NTRS)

Elosegui, Pedro

2004-01-01

The few millimeter per year level accuracy of radial global velocity estimates with the Global Positioning System (GPS) is at least an order of magnitude poorer than the accuracy of horizontal global motions. An improvement in the accuracy of radial global velocities would have a very positive impact on a number of geophysical studies of current general interest such as global sea-level and climate change, coastal hazards, glacial isostatic adjustment, atmospheric and oceanic loading, glaciology and ice mass variability, tectonic deformation and volcanic inflation, and geoid variability. The goal of this project is to improve our current understanding of GPS error sources associated with estimates of radial velocities at global scales. GPS error sources relevant to this project can be classified in two broad categories: (1) those related to the analysis of the GPS phase observable, and (2) those related to the combination of the positions and velocities of a set of globally distributed stations as determined from the analysis of GPS data important aspect in the first category include the effect on vertical rate estimates due to standard analysis choices, such as orbit modeling, network geometry, ambiguity resolution, as well as errors in models (or simply the lack of models) for clocks, multipath, phase-center variations, atmosphere, and solid-Earth tides. The second category includes the possible methods of combining and defining terrestrial reference flames for determining vertical velocities in a global scale. The latter has been the subject of our research activities during this reporting period.

PID position regulation in one-degree-of-freedom Euler-Lagrange systems actuated by a PMSM

NASA Astrophysics Data System (ADS)

Verastegui-Galván, J.; Hernández-Guzmán, V. M.; Orrante-Sakanassi, J.

2018-02-01

This paper is concerned with position regulation in one-degree-of-freedom Euler-Lagrange Systems. We consider that the mechanical subsystem is actuated by a permanent magnet synchronous motor (PMSM). Our proposal consists of a Proportional-Integral-Derivative (PID) controller for the mechanical subsystem and a slight variation of field oriented control for the PMSM. We take into account the motor electric dynamics during the stability analysis. We present, for the first time, a global asymptotic stability proof for such a control scheme without requiring the mechanical subsystem to naturally possess viscous friction. Finally, as a corollary of our main result we prove global asymptotic stability for output feedback PID regulation of one-degree-of-freedom Euler-Lagrange systems when generated torque is considered as the system input, i.e. when the electric dynamics of PMSM's is not taken into account.

An approach to regional wetland digital elevation model development using a differential global positioning system and a custom-built helicopter-based surveying system

USGS Publications Warehouse

Jones, J.W.; Desmond, G.B.; Henkle, C.; Glover, R.

2012-01-01

Accurate topographic data are critical to restoration science and planning for the Everglades region of South Florida, USA. They are needed to monitor and simulate water level, water depth and hydroperiod and are used in scientific research on hydrologic and biologic processes. Because large wetland environments and data acquisition challenge conventional ground-based and remotely sensed data collection methods, the United States Geological Survey (USGS) adapted a classical data collection instrument to global positioning system (GPS) and geographic information system (GIS) technologies. Data acquired with this instrument were processed using geostatistics to yield sub-water level elevation values with centimetre accuracy (??15 cm). The developed database framework, modelling philosophy and metadata protocol allow for continued, collaborative model revision and expansion, given additional elevation or other ancillary data. ?? 2012 Taylor & Francis.

Spaceborne GPS Current Status and Future Visions

NASA Technical Reports Server (NTRS)

Bauer, Frank H.; Hartman, Kate; Lightsey, E. Glenn

1998-01-01

The Global Positioning System (GPS), developed by the Department of Defense, is quickly revolutionizing the architecture of future spacecraft and spacecraft systems. Significant savings in spacecraft life cycle cost, in power, and in mass can be realized by exploiting Global Positioning System (GPS) technology in spaceborne vehicles. These savings are realized because GPS is a systems sensor-it combines the ability to sense space vehicle trajectory, attitude, time, and relative ranging between vehicles into one package. As a result, a reduced spacecraft sensor complement can be employed on spacecraft and significant reductions in space vehicle operations cost can be realized through enhanced on- board autonomy. This paper provides an overview of the current status of spaceborne GPS, a description of spaceborne GPS receivers available now and in the near future, a description of the 1997-1999 GPS flight experiments and the spaceborne GPS team's vision for the future.

Airborne Digital Sensor System and GPS-aided inertial technology for direct geopositioning in rough terrain

USGS Publications Warehouse

Sanchez, Richard D.

2004-01-01

High-resolution airborne digital cameras with onboard data collection based on the Global Positioning System (GPS) and inertial navigation systems (INS) technology may offer a real-time means to gather accurate topographic map information by reducing ground control and eliminating aerial triangulation. Past evaluations of this integrated system over relatively flat terrain have proven successful. The author uses Emerge Digital Sensor System (DSS) combined with Applanix Corporation?s Position and Orientation Solutions for Direct Georeferencing to examine the positional mapping accuracy in rough terrain. The positional accuracy documented in this study did not meet large-scale mapping requirements owing to an apparent system mechanical failure. Nonetheless, the findings yield important information on a new approach for mapping in Antarctica and other remote or inaccessible areas of the world.

Geospatial Technology

ERIC Educational Resources Information Center

Reed, Philip A.; Ritz, John

2004-01-01

Geospatial technology refers to a system that is used to acquire, store, analyze, and output data in two or three dimensions. This data is referenced to the earth by some type of coordinate system, such as a map projection. Geospatial systems include thematic mapping, the Global Positioning System (GPS), remote sensing (RS), telemetry, and…

Transatlantic Relations: The Role of Nationalism in Multinational Space Cooperation

DTIC Science & Technology

2009-06-01

Global Positioning System (GPS) and Russia’s Global’naya Navigatsionnaya Sputnikovaya Sistema (GLONASS), is another program that has seen its...ESA official Web pages, as well as public documents, such as Reports to Congress (CRS) and European Policy Papers written by authors such as Carl...Global’naya Navigatsionnaya Sputnikovaya Sistema (GLONASS). It is the first large program jointly funded by the EU and ESA and is also the first major

Flight Mechanics/Estimation Theory Symposium

NASA Technical Reports Server (NTRS)

Fuchs, A. J. (Editor)

1980-01-01

Methods of determining satellite orbit and attitude parameters are considered. The Goddard Trajectory Determination System, the Global Positioning System, and the Tracking and Data Relay Satellites are among the satellite navigation systems discussed. Satellite perturbation theory, orbit/attitude determination using landmark data, and star measurements are also covered.

75 FR 11477 - Proposed Establishment of Class E Airspace; Kemmerer, WY

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-11

... new Area Navigation (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedures... be submitted in triplicate to the Docket Management System (see ADDRESSES section for address and... Proposed Rulemaking Distribution System, which describes the application procedure. The Proposal The FAA is...

Wireless global positioning system fleet tracking system at the University at Albany.

DOT National Transportation Integrated Search

2014-07-01

This report provides an overview of the project undertaken at the University at Albany to make alternative transportation a more : viable option by implementing a GPS Tracking System on the University bus fleet and broadcasting the bus locations to c...

Development of vehicular and personal universal longitudinal travel diary systems using GPS and new technology.

DOT National Transportation Integrated Search

2006-12-01

This report provides an overview of travel surveys, including literature review and background, as well as the motivation for the : research and development of the Global Positioning System Automated Travel Diary (GPS-ATD). The system requirements an...

Project Catch: A space based solution to combat illegal, unreported and unregulated fishing. Part I: Vessel monitoring system

NASA Astrophysics Data System (ADS)

Detsis, Emmanouil; Brodsky, Yuval; Knudtson, Peter; Cuba, Manuel; Fuqua, Heidi; Szalai, Bianca

2012-11-01

Space assets have a unique opportunity to play a more active role in global resource management. There is a clear need to develop resource management tools in a global framework. Illegal, Unregulated and Unreported (IUU) fishing is placing pressure on the health and size of fishing stocks around the world. Earth observation systems can provide fishery management organizations with cost effective monitoring of large swaths of ocean. Project Catch is a fisheries management project based upon the complimentary, but independent Catch-VMS and Catch-GIS systems. Catch-VMS is a Vessel Monitoring System with increased fidelity over existing offerings. Catch-GIS is a Geographical Information System that combines VMS information with existing Earth Observation data and other data sources to identify Illegal, Unregulated and Unreported (IUU) fishing. Project Catch was undertaken by 19 Masters students from the 2010 class of the International Space University. In this paper, the space-based system architecture of Project Catch is presented and analyzed. The rationale for the creation of the system, as well as the engineering trade-off studies in its creation, are discussed. The Catch-VMS proposal was envisaged in order to address two specific problems: (1) the expansion of illegal fishing to high-latitude regions where existing satellite systems coverage is an issue and (2) the lack of coverage in remote oceanic regions due to reliance on coastal-based monitoring. Catch-VMS utilizes ship-borne transponders and hosted-payload receivers on a Global Navigation Satellite System in order to monitor the position and activity of compliant fishing vessels. Coverage is global and continuous with multiple satellites in view providing positional verification through multilateration techniques. The second part of the paper briefly describes the Catch-GIS system and investigates its cost of implementation.

Physical applications of GPS geodesy: a review.

PubMed

Bock, Yehuda; Melgar, Diego

2016-10-01

Geodesy, the oldest science, has become an important discipline in the geosciences, in large part by enhancing Global Positioning System (GPS) capabilities over the last 35 years well beyond the satellite constellation's original design. The ability of GPS geodesy to estimate 3D positions with millimeter-level precision with respect to a global terrestrial reference frame has contributed to significant advances in geophysics, seismology, atmospheric science, hydrology, and natural hazard science. Monitoring the changes in the positions or trajectories of GPS instruments on the Earth's land and water surfaces, in the atmosphere, or in space, is important for both theory and applications, from an improved understanding of tectonic and magmatic processes to developing systems for mitigating the impact of natural hazards on society and the environment. Besides accurate positioning, all disturbances in the propagation of the transmitted GPS radio signals from satellite to receiver are mined for information, from troposphere and ionosphere delays for weather, climate, and natural hazard applications, to disturbances in the signals due to multipath reflections from the solid ground, water, and ice for environmental applications. We review the relevant concepts of geodetic theory, data analysis, and physical modeling for a myriad of processes at multiple spatial and temporal scales, and discuss the extensive global infrastructure that has been built to support GPS geodesy consisting of thousands of continuously operating stations. We also discuss the integration of heterogeneous and complementary data sets from geodesy, seismology, and geology, focusing on crustal deformation applications and early warning systems for natural hazards.

Battlefield Object Control via Internet Architecture

DTIC Science & Technology

2002-01-01

superiority is the best way to reach the goal of competition superiority. Using information technology (IT) in data processing, including computer hardware... technologies : Global Positioning System (GPS), Geographic Information System (GIS), Battlefield Information Transmission System (BITS), and Intelligent...operational environment. Keywords: C4ISR Systems, Information Superiority, Battlefield Objects, Computer - Aided Prototyping System (CAPS), IP-based

33 CFR 164.43 - Automatic Identification System Shipborne Equipment-Prince William Sound.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (AISSE) system consisting of a: (1) Twelve-channel all-in-view Differential Global Positioning System (d... to indicate to shipboard personnel that the U.S. Coast Guard dGPS system cannot provide the required... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Automatic Identification System...

Statistics on Diphtheria

MedlinePlus

... and diseases Global Vaccine Action Plan WHO policy recommendations SAGE Immunization schedules Position papers Advisory committees National programmes and systems Policy and strategies Service delivery Linking with other ...

Modeling the plasmasphere based on LEO satellites onboard GPS measurements

NASA Astrophysics Data System (ADS)

Chen, Peng; Yao, Yibin; Li, Qinzheng; Yao, Wanqiang

2017-01-01

The plasmasphere, which is located above the ionosphere, is a significant component of Earth's atmosphere. A global plasmaspheric model was constructed using the total electron content (TEC) along the signal propagation path calculated using onboard Global Positioning System observations from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) and MetOp-A, provided by the COSMIC Data Analysis and Archive Center (CDAAC). First, the global plasmaspheric model was established using only COSMIC TEC, and a set of MetOp-A TEC provided by CDAAC served for external evaluation. Results indicated that the established model using only COSMIC data is highly accurate. Then, COSMIC and MetOp-A TEC were combined to produce a new global plasmaspheric model. Finally, the variational characteristics of global plasmaspheric electron content with latitude, local time, and season were investigated using the global plasmaspheric model established in this paper.

Relativistic Positioning Systems and Gravitational Perturbations

NASA Astrophysics Data System (ADS)

Gomboc, Andreja; Kostić, Uroš; Horvat, Martin; Carloni, Sante; Delva, Pacôme

2013-11-01

In order to deliver a high accuracy relativistic positioning system, several gravitational perturbations need to be taken into account. We therefore consider a system of satellites, such as the Galileo system, in a space-time described by a background Schwarzschild metric and small gravitational perturbations due to the Earth’s rotation, multipoles and tides, and the gravity of the Moon, the Sun, and planets. We present the status of this work currently carried out in the ESA Slovenian PECS project Relativistic Global Navigation System, give the explicit expressions for the perturbed metric, and briefly outline further steps.

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle

NASA Technical Reports Server (NTRS)

Upadhyay, Triveni N.; Cotterill, Stephen; Deaton, A. W.

1993-01-01

An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle (STV)

NASA Technical Reports Server (NTRS)

Upadhyay, Triveni N.; Cotterill, Stephen; Deaton, A. Wayne

1991-01-01

An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle

NASA Astrophysics Data System (ADS)

Upadhyay, Triveni N.; Cotterill, Stephen; Deaton, A. W.

1993-07-01

An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

NASA's global differential GPS system and the TDRSS augmentation service for satellites

NASA Technical Reports Server (NTRS)

Bar-Sever, Yoaz; Young, Larry; Stocklin, Frank; Rush, John

2004-01-01

NASA is planning to launch a new service for Earth satellites providing them with precise GPS differential corrections and other ancillary information enabling decimeter level orbit determination accuracy, and nanosecond time-transfer accuracy, onboard, in real-time. The TDRSS Augmentation Service for Satellites (TASS) will broadcast its message on the S-band multiple access channel of NASA's Tracking and Data Relay Satellite System (TDRSS). The satellite's phase array antenna has been configured to provide a wide beam, extending coverage up to 1000 km altitude over the poles. Global coverage will be ensured with broadcast from three or more TDRSS satellites. The GPS differential corrections are provided by the NASA Global Differential GPS (GDGPS) System, developed and operated by NASA's Jet Propulsion Laboratory. The GDGPS System employs a global ground network of more than 70 GPS receivers to monitor the GPS constellation in real time. The system provides real-time estimates of the GPS satellite states, as well as many other real-time products such as differential corrections, global ionospheric maps, and integrity monitoring. The unique multiply redundant architecture of the GDGPS System ensures very high reliability, with 99.999% demonstrated since the inception of the system in Early 2000. The estimated real time GPS orbit and clock states provided by the GDGPS system are accurate to better than 20 cm 3D RMS, and have been demonstrated to support sub-decimeter real time positioning and orbit determination for a variety of terrestrial, airborne, and spaceborne applications. In addition to the GPS differential corrections, TASS will provide real-time Earth orientation and solar flux information that enable precise onboard knowledge of the Earth-fixed position of the spacecraft, and precise orbit prediction and planning capabilities. TASS will also provide 5 seconds alarms for GPS integrity failures based on the unique GPS integrity monitoring service of the GDGPS System.

Match-to-match variation in physical activity and technical skill measures in professional Australian Football.

PubMed

Kempton, Thomas; Sullivan, Courtney; Bilsborough, Johann C; Cordy, Justin; Coutts, Aaron J

2015-01-01

To determine the match-to-match variability in physical activity and technical performance measures in Australian Football, and examine the influence of playing position, time of season, and different seasons on these measures of variability. Longitudinal observational study. Global positioning system, accelerometer and technical performance measures (total kicks, handballs, possessions and Champion Data rank) were collected from 33 players competing in the Australian Football League over 31 matches during 2011-2012 (N=511 observations). The global positioning system data were categorised into total distance, mean speed (mmin(-1)), high-speed running (>14.4 kmh(-1)), very high-speed running (>19.9 kmh(-1)), and sprint (>23.0 kmh(-1)) distance while player load was collected from the accelerometer. The data were log transformed to provide coefficient of variation and the between subject standard deviation (expressed as percentages). Match-to-match variability was increased for higher speed activities (high-speed running, very high-speed running, sprint distance, coefficient of variation %: 13.3-28.6%) compared to global measures (speed, total distance, player load, coefficient of variation %: 5.3-9.2%). The between-match variability was relativity stable for all measures between and within AFL seasons, with only few differences between positions. Higher speed activities (high-speed running, very high-speed running, sprint distance), but excluding mean speed, total distance and player load, were all higher in the final third phase of the season compared to the start of the season. While global measures of physical performance are relatively stable, higher-speed activities and technical measures exhibit a large degree of between-match variability in Australian Football. However, these measures remain relatively stable between positions, and within and between Australian Football League seasons. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Global regulators ExpA (GacA) and KdgR modulate extracellular enzyme gene expression through the RsmA-rsmB system in Erwinia carotovora subsp. carotovora.

PubMed

Hyytiäinen, H; Montesano, M; Palva, E T

2001-08-01

The production of the main virulence determinants, the extracellular plant cell wall-degrading enzymes, and hence virulence of Erwinia carotovora subsp. carotovora is controlled by a complex regulatory network. One of the global regulators, the response regulator ExpA, a GacA homolog, is required for transcriptional activation of the extracellular enzyme genes of this soft-rot pathogen. To elucidate the mechanism of ExpA control as well as interactions with other regulatory systems, we isolated second-site transposon mutants that would suppress the enzyme-negative phenotype of an expA (gacA) mutant. Inactivation of kdgR resulted in partial restoration of extracellular enzyme production and virulence to the expA mutant, suggesting an interaction between the two regulatory pathways. This interaction was mediated by the RsmA-rsmB system. Northern analysis was used to show that the regulatory rsmB RNA was under positive control of ExpA. Conversely, the expression of rsmA encoding a global repressor was under negative control of ExpA and positive control of KdgR. This study indicates a central role for the RsmA-rsmB regulatory system during pathogenesis, integrating signals from the ExpA (GacA) and KdgR global regulators of extracellular enzyme production in E. carotovora subsp. carotovora.

27th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

NASA Technical Reports Server (NTRS)

Sydnor, Richard L. (Editor)

1996-01-01

This document is a compilation of technical papers presented at the 27th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, held November 29 - December 1, 1995 at San Diego, CA. Papers are in the following categories: Recent developments in rubidium, cesium, and hydrogen-based frequency standards; and in cryogenic and trapped-ion technology; International and transnational applications of PTTI technology with emphasis on satellite laser tracking, GLONASS timing, intercomparison of national time scales and international telecommunications; Applications of PTTI technology to the telecommunications, power distribution, platform positioning, and geophysical survey industries; Applications of PTTI technology to evolving military communications and navigation systems; and Dissemination of precise time and frequency by means of Global Positioning System (GPS), Global Satellite Navigation System (GLONASS), MILSTAR, LORAN, and synchronous communications satellites.

Measuring Global Position Using the Sun

ERIC Educational Resources Information Center

Murphy, Evan; Hughes, Stephen

2014-01-01

The determination of latitude and longitude on Earth has always been of interest to explorers and cartographers alike. Accurate positional information is often needed for rescue purposes in locations where satellite navigational systems are inoperable. The activity described in this paper demonstrates a simple procedure to determine latitude and…

Terrestrial Evaluation of the Global Positioning System (GPS), Standard Positioning Service (SPS)

DOT National Transportation Integrated Search

1986-04-01

The report summarizes the results of static and navigation tests conducted in the Boston, Massachusetts area during the period of January through April 1985 and also in August 1985. The objective of these tests was to gather data to determine the via...

Intraformation positioning system

NASA Astrophysics Data System (ADS)

Sheldon, Stuart; Zadzora, Timothy

1996-05-01

The IntraFormation Positioning System is a networked relative navigation system currently being developed for rendezvous, join-up, and formation flight of Air Force helicopters and fixed wing aircraft in instrument meteorological conditions. The system is designed to be integrated into existing aircraft and will display relative positions of all aircraft within a formation, as well as the relative positions of other formations participating in coordinated missions. The system uses a Global Positioning System receiver integrated with the aircraft Inertial Navigation System to generate accurate aircraft position and velocity data. These data are transmitted over a data link to all participating aircraft and displayed as graphic symbols at the relative range and bearing to own aircraft on a situational awareness display format similar to a radar plan position indicator. Flight guidance computation is based on the difference between a desired formation slot position and current aircraft position relative to the formation lead aircraft. This information is presented on the flight director display allowing the pilot to null out position errors. The system is being developed for the Air Force Special Operations Command; however, it is applicable to all aircraft desiring improved formation situational awareness and formation flight coordination.

The NavTrax fleet management system

NASA Astrophysics Data System (ADS)

McLellan, James F.; Krakiwsky, Edward J.; Schleppe, John B.; Knapp, Paul L.

The NavTrax System, a dispatch-type automatic vehicle location and navigation system, is discussed. Attention is given to its positioning, communication, digital mapping, and dispatch center components. The positioning module is a robust GPS (Global Positioning System)-based system integrated with dead reckoning devices by a decentralized-federated filter, making the module fault tolerant. The error behavior and characteristics of GPS, rate gyro, compass, and odometer sensors are discussed. The communications module, as presently configured, utilizes UHF radio technology, and plans are being made to employ a digital cellular telephone system. Polling and automatic smart vehicle reporting are also discussed. The digital mapping component is an intelligent digital single line road network database stored in vector form with full connectivity and address ranges. A limited form of map matching is performed for the purposes of positioning, but its main purpose is to define location once position is determined.

Nationwide differential global positioning system (NDGPS) : capabilities and potential.

DOT National Transportation Integrated Search

2009-06-01

NDGPS is a National PNT Utility: : -Operated/managed by Coast Guard as a Combined NDGPS (Maritime + DOT + ACOE sites) : -System Specifications : --Corrections broadcast at 285 and 325 kHz using Minimum shift Keying (MSK) modulation : --Real-time diff...

Understanding ITS/CVO Technology Applications, Student Manual, Course 3

DOT National Transportation Integrated Search

1999-01-01

WEIGHT-IN-MOTION OR WIM, COMMERCIAL VEHICLE INFORMATION SYSTEMS AND NETWORK OR CVISN, AUTOMATIC VEHICLE IDENTIFICATION OR AVI, AUTOMATIC LOCATION OR AVL, ELECTRONIC DATA INTERCHANGE OR EDI, GLOBAL POSITIONING SYSTEM OR GPS, INTERNET OR WORLD WIDE WEB...

Case studies in collecting highway inventory data with the Global Positioning System.

DOT National Transportation Integrated Search

1996-01-01

A number of state departments of transportation, including the Virginia Department of Transportation (VDOT), are developing a geographic information system (GIS) to integrate data and to conduct more elaborate analyses which will improve their decisi...

High-Precision Image Aided Inertial Navigation with Known Features: Observability Analysis and Performance Evaluation

PubMed Central

Jiang, Weiping; Wang, Li; Niu, Xiaoji; Zhang, Quan; Zhang, Hui; Tang, Min; Hu, Xiangyun

2014-01-01

A high-precision image-aided inertial navigation system (INS) is proposed as an alternative to the carrier-phase-based differential Global Navigation Satellite Systems (CDGNSSs) when satellite-based navigation systems are unavailable. In this paper, the image/INS integrated algorithm is modeled by a tightly-coupled iterative extended Kalman filter (IEKF). Tightly-coupled integration ensures that the integrated system is reliable, even if few known feature points (i.e., less than three) are observed in the images. A new global observability analysis of this tightly-coupled integration is presented to guarantee that the system is observable under the necessary conditions. The analysis conclusions were verified by simulations and field tests. The field tests also indicate that high-precision position (centimeter-level) and attitude (half-degree-level)-integrated solutions can be achieved in a global reference. PMID:25330046

Global positioning system surveying to monitor land subsidence in Sacramento Valley, California, USA

USGS Publications Warehouse

Ikehara, M.E.

1994-01-01

A subsidence research program began in 1985 to document the extent and magnitude of land subsidence in Sacramento Valley, California, an area of about 15 600 km2m, using Global Positioning System (GPS) surveying. In addition to periodic conventional spirit levelling, an examination was made of the changes in GPS-derived ellipsoidal height differences (summary differences) between pairs of adjacent bench marks in central Sacramento Valley from 1986 to 1989. The average rates of land subsidence in the southern Sacramento Valley for the past several decades were determined by comparing GPS-derived orthometric heights with historic published elevations. A maximum average rate of 0.053 m year-1 (0.90 m in 17 years) of subsidence has been measured. -Author

Some tests of wet tropospheric calibration for the CASA Uno Global Positioning System experiment

NASA Technical Reports Server (NTRS)

Dixon, T. H.; Wolf, S. Kornreich

1990-01-01

Wet tropospheric path delay can be a major error source for Global Positioning System (GPS) geodetic experiments. Strategies for minimizing this error are investigted using data from CASA Uno, the first major GPS experiment in Central and South America, where wet path delays may be both high and variable. Wet path delay calibration using water vapor radiometers (WVRs) and residual delay estimation is compared with strategies where the entire wet path delay is estimated stochastically without prior calibration, using data from a 270-km test baseline in Costa Rica. Both approaches yield centimeter-level baseline repeatability and similar tropospheric estimates, suggesting that WVR calibration is not critical for obtaining high precision results with GPS in the CASA region.

What can global positioning systems tell us about the contribution of different types of urban greenspace to children’s physical activity?

PubMed Central

Lachowycz, Kate; Jones, Andrew P.; Page, Angie S.; Wheeler, Benedict W.; Cooper, Ashley R.

2013-01-01

Urban greenspace is hypothesised to be an important location for physical activity in children, but their actual use of the resource to be active is not well known. In this study, global positioning systems (GPS) and accelerometers were used to measure activity within green environments for 902 English children aged 11-12. We summarised activity intensities in different types of greenspace on weekday evenings, weekend days, and by season. Parks were used for as much as 30% of outdoors moderate-vigorous activity at weekends and use was consistent across seasons. The findings suggest the importance of certain types of greenspace to children’s physical activity. PMID:22365385

Determination of the centre of mass kinematics in alpine skiing using differential global navigation satellite systems.

PubMed

Gilgien, Matthias; Spörri, Jörg; Chardonnens, Julien; Kröll, Josef; Limpach, Philippe; Müller, Erich

2015-01-01

In the sport of alpine skiing, knowledge about the centre of mass (CoM) kinematics (i.e. position, velocity and acceleration) is essential to better understand both performance and injury. This study proposes a global navigation satellite system (GNSS)-based method to measure CoM kinematics without restriction of capture volume and with reasonable set-up and processing requirements. It combines the GNSS antenna position, terrain data and the accelerations acting on the skier in order to approximate the CoM location, velocity and acceleration. The validity of the method was assessed against a reference system (video-based 3D kinematics) over 12 turn cycles on a giant slalom skiing course. The mean (± s) position, velocity and acceleration differences between the CoM obtained from the GNSS and the reference system were 9 ± 12 cm, 0.08 ± 0.19 m · s(-1) and 0.22 ± 1.28 m · s(-2), respectively. The velocity and acceleration differences obtained were smaller than typical differences between the measures of several skiers on the same course observed in the literature, while the position differences were slightly larger than its discriminative meaningful change. The proposed method can therefore be interpreted to be technically valid and adequate for a variety of biomechanical research questions in the field of alpine skiing with certain limitations regarding position.

76 FR 45479 - Proposed Establishment of Class E Airspace; Bumpass, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-29

...) Global Positioning System (GPS) Standard Instrument Approach Procedures serving Lake Anna Airport. This... within the National Airspace System. DATES: Comments must be received on or before September 12, 2011... distribution System, which describes the application procedure. The Proposal The FAA is considering an...

Relationship Between Site Disturbance and Forest Harvesting Equipment Traffic

Treesearch

Tim McDonald; Emily Carter; Steve Taylor; John Tobert

1998-01-01

A study was done to evaluate the use of global positioning systems (GPS) to track the position of forest harvesting equipment and use the information to assess site impacts. GPS units were attached to tree-length harvesting machinery in two clearcuts (1 feller-buncher, 2 skidders). Position of the equipment was recorded at 2-second intervals throughout the harvest of...

Smart Device-Supported BDS/GNSS Real-Time Kinematic Positioning for Sub-Meter-Level Accuracy in Urban Location-Based Services

PubMed Central

Wang, Liang; Li, Zishen; Zhao, Jiaojiao; Zhou, Kai; Wang, Zhiyu; Yuan, Hong

2016-01-01

Using mobile smart devices to provide urban location-based services (LBS) with sub-meter-level accuracy (around 0.5 m) is a major application field for future global navigation satellite system (GNSS) development. Real-time kinematic (RTK) positioning, which is a widely used GNSS-based positioning approach, can improve the accuracy from about 10–20 m (achieved by the standard positioning services) to about 3–5 cm based on the geodetic receivers. In using the smart devices to achieve positioning with sub-meter-level accuracy, a feasible solution of combining the low-cost GNSS module and the smart device is proposed in this work and a user-side GNSS RTK positioning software was developed from scratch based on the Android platform. Its real-time positioning performance was validated by BeiDou Navigation Satellite System/Global Positioning System (BDS/GPS) combined RTK positioning under the conditions of a static and kinematic (the velocity of the rover was 50–80 km/h) mode in a real urban environment with a SAMSUNG Galaxy A7 smartphone. The results show that the fixed-rates of ambiguity resolution (the proportion of epochs of ambiguities fixed) for BDS/GPS combined RTK in the static and kinematic tests were about 97% and 90%, respectively, and the average positioning accuracies (RMS) were better than 0.15 m (horizontal) and 0.25 m (vertical) for the static test, and 0.30 m (horizontal) and 0.45 m (vertical) for the kinematic test. PMID:28009835

The national- and international-wide prospects of future improvements of position location and time synchronization systems and aids

NASA Technical Reports Server (NTRS)

Gouzhva, Yuri G.; Balyasnikov, Boris N.; Korniyenko, Vladimir V.; Pushkina, Irina G.; Shebshayevich, Valentin S.; Denisov, Vladimir I.; Reutov, Alexander P.

1990-01-01

The concept being designed by the Leningrad Scientific Research Radio Technical Institute (LSRRI) of united positioning and timing service on the basis of the utilization of long-range and global radionavigation and common time systems and aids for different users is described. The estimate of its utilization on the national as well as on international scale is given.

GPS/GLONASS Time Transfer with 20-Channel Dual GNSS Receiver

NASA Technical Reports Server (NTRS)

Daly, P.; Riley, S.

1996-01-01

One of the world's two global navigation systems, the Global Positioning System (GPS), is already fully operational (April 1994) and the other, the Global Navigation Satellite System (GLONASS) will become operational by the end of 1995 or early 1996. Each will offer, independently of the other, precise location and time transfer continuously anywhere in the world and indeed in space itself. Many potential users, in particular the civil aviation community, are keenly interested in a joint GPS/GLONASS operation since it would offer substantial advantages in defining and maintaining the integrity of the navigation aid. Results are presented on the characterization of GPS/GLONASS time comparison using a 20-channel dual receiver developed and constructed at the University of Leeds, UK.

Transformational Leadership in the Educational System of the United Arab Emirates

ERIC Educational Resources Information Center

Litz, David; Scott, Shelleyann

2017-01-01

Globally, there is increasing pressure on schools to enact change, and the literature indicates that transformational leadership is positively associated with school leaders' effectiveness at implementing positive reforms. Here, we report on a study conducted in the United Arab Emirates (UAE) within the current context of intense educational…

Chemical Tracking Systems: Not Your Usual Global Positioning System!

ERIC Educational Resources Information Center

Roy, Ken

2007-01-01

The haphazard storing and tracking of chemicals in the laboratory is a serious safety issue facing science teachers. To get control of your chemicals, try implementing a "chemical tracking system". A chemical tracking system (CTS) is a database of chemicals used in the laboratory. If implemented correctly, a CTS will reduce purchasing costs,…

Functional Requirements Study

DTIC Science & Technology

2008-07-01

Identification System, AIS, Vessel Traffic Services, VTS, Transmit, Broadcast, Functional Requirements, United States Coast Guard, USCG, Mariner, Electronic ...Chart Systems, ECS, Vessel Operators, National Oceanic Atmospheric Administration, NOAA, US Army Corp of Engineers , USACE, ECDIS 18. Distribution...and River Information Service COPT Captain of the Port DGPS Differential Global Positioning System ECDIS Electronic Chart Display Information System

Enhancing Autonomy of Aerial Systems Via Integration of Visual Sensors into Their Avionics Suite

DTIC Science & Technology

2016-09-01

aerial platform for subsequent visual sensor integration. 14. SUBJECT TERMS autonomous system, quadrotors, direct method, inverse ...CONTROLLER ARCHITECTURE .....................................................43 B. INVERSE DYNAMICS IN THE VIRTUAL DOMAIN ......................45 1...control station GPS Global-Positioning System IDVD inverse dynamics in the virtual domain ILP integer linear program INS inertial-navigation system

High order GPS base station support for Rhode Island

DOT National Transportation Integrated Search

2001-09-01

The University of Rhode Island (URI) upgraded its Global Positioning System (GPS) Base Station to provide round-the-clock Internet access to survey-grade (+/- 2 cm accuracy) reference files using a web-based data distribution system. In August 2000, ...

Flexible Control and Interprocess Communication on the Rogue GPS Receiver

NASA Technical Reports Server (NTRS)

Blau, R.

1999-01-01

The Rogue receivers are a series of custom high-accuracy Global Positioning System receivers being developed at NASA's Jet Propulsion Laboratory. This thesis describes two additions to the RogueOS, a custom operation system developed for these recievers.

Mapping Indigenous Depth of Place

ERIC Educational Resources Information Center

Pearce, Margaret Wickens; Louis, Renee Pualani

2008-01-01

Indigenous communities have successfully used Western geospatial technologies (GT) (for example, digital maps, satellite images, geographic information systems (GIS), and global positioning systems (GPS)) since the 1970s to protect tribal resources, document territorial sovereignty, create tribal utility databases, and manage watersheds. The use…

Exploration of GPS to enhance the safe transport of hazardous materials

DOT National Transportation Integrated Search

1997-12-01

The report (1) documents a set of requirements for the performance of location systems that utilize the Global Positioning System (GPS), (2) identifies potential uses of GPS in hazardous materials transport, (3) develops service descriptions for the ...

Assessment of Two Types of Observations (SATWND and GPSRO) for the Operational Global 4DVAR System

NASA Astrophysics Data System (ADS)

Leng, H.

2017-12-01

The performance of a data assimilation system is significantly dependent on the quality and quantity of observations assimilated. In these years, more and more satellite observations have been applied in many operational assimilation systems. In this paper, the assessment of satellite-derived winds (SATWND) and GPS radio occultation (GPSRO) bending angles has been performed using a range of diagnostics. The main positive impacts are made when satellite-derived cloud data (GOES cloud data and MODIS cloud data) is assimilated, but benefit is hardly obtained from GPSRO data in the Operational Global 4DVAR System. In a full system configuration, the assimilation of satellite-derived observations is globally beneficial on the analysis, and the benefit can be well propagated into the forecast. The assimilation of the GPSRO observations has a slightly positive impact in the Tropics, but is neutral in the Northern Hemisphere and in the Southern Hemisphere. To assess the synergies of satellite-derived observations with other types of observation, experiments assimilating satellite-derived data and AMSU-A and AMSU-B observations were run. The results show that the analysis increments structure is not modified when AMSU-A and AMSU-B observations are also assimilated. This suggests that the impact of satellite-derived observations is not limited by the large impact of satellite radiance observations.

Tightly-Coupled Integration of Multi-GNSS Single-Frequency RTK and MEMS-IMU for Enhanced Positioning Performance

PubMed Central

Li, Tuan; Zhang, Hongping; Niu, Xiaoji; Gao, Zhouzheng

2017-01-01

Dual-frequency Global Positioning System (GPS) Real-time Kinematics (RTK) has been proven in the past few years to be a reliable and efficient technique to obtain high accuracy positioning. However, there are still challenges for GPS single-frequency RTK, such as low reliability and ambiguity resolution (AR) success rate, especially in kinematic environments. Recently, multi-Global Navigation Satellite System (multi-GNSS) has been applied to enhance the RTK performance in terms of availability and reliability of AR. In order to further enhance the multi-GNSS single-frequency RTK performance in terms of reliability, continuity and accuracy, a low-cost micro-electro-mechanical system (MEMS) inertial measurement unit (IMU) is adopted in this contribution. We tightly integrate the single-frequency GPS/BeiDou/GLONASS and MEMS-IMU through the extended Kalman filter (EKF), which directly fuses the ambiguity-fixed double-differenced (DD) carrier phase observables and IMU data. A field vehicular test was carried out to evaluate the impacts of the multi-GNSS and IMU on the AR and positioning performance in different system configurations. Test results indicate that the empirical success rate of single-epoch AR for the tightly-coupled single-frequency multi-GNSS RTK/INS integration is over 99% even at an elevation cut-off angle of 40°, and the corresponding position time series is much more stable in comparison with the GPS solution. Besides, GNSS outage simulations show that continuous positioning with certain accuracy is possible due to the INS bridging capability when GNSS positioning is not available. PMID:29077070

Tightly-Coupled Integration of Multi-GNSS Single-Frequency RTK and MEMS-IMU for Enhanced Positioning Performance.

PubMed

Li, Tuan; Zhang, Hongping; Niu, Xiaoji; Gao, Zhouzheng

2017-10-27

Dual-frequency Global Positioning System (GPS) Real-time Kinematics (RTK) has been proven in the past few years to be a reliable and efficient technique to obtain high accuracy positioning. However, there are still challenges for GPS single-frequency RTK, such as low reliability and ambiguity resolution (AR) success rate, especially in kinematic environments. Recently, multi-Global Navigation Satellite System (multi-GNSS) has been applied to enhance the RTK performance in terms of availability and reliability of AR. In order to further enhance the multi-GNSS single-frequency RTK performance in terms of reliability, continuity and accuracy, a low-cost micro-electro-mechanical system (MEMS) inertial measurement unit (IMU) is adopted in this contribution. We tightly integrate the single-frequency GPS/BeiDou/GLONASS and MEMS-IMU through the extended Kalman filter (EKF), which directly fuses the ambiguity-fixed double-differenced (DD) carrier phase observables and IMU data. A field vehicular test was carried out to evaluate the impacts of the multi-GNSS and IMU on the AR and positioning performance in different system configurations. Test results indicate that the empirical success rate of single-epoch AR for the tightly-coupled single-frequency multi-GNSS RTK/INS integration is over 99% even at an elevation cut-off angle of 40°, and the corresponding position time series is much more stable in comparison with the GPS solution. Besides, GNSS outage simulations show that continuous positioning with certain accuracy is possible due to the INS bridging capability when GNSS positioning is not available.

GPS-Only Terrestrial Reference Frame Based on a Global Reprocessing

NASA Astrophysics Data System (ADS)

Dietrich, R.; Rothacher, M.; Ruelke, A.; Fritsche, M.; Steigenberger, P.

2007-12-01

The realization of the International Terrestrial Reference System (ITRS) with highest accuracy and stability is fundamental and crucial for applications in geodesy, geodynamics, geophysics and global change. In a joint effort TU Dresden and TU Munich/GFZ Potsdam reprocessed a global GPS network of more than 200 stations. As a contribution to an ITRS realization daily normal equations from 1994 to 2005 were rigorously combined in order to determine a global GPS-only reference frame (PDR05/Potsdam-Dresden-Reprocessing Reference Frame). We present a realization of the global terrestrial reference system which follows the center of mass approach in consideration of the load-induced deformation of the Earth's crust due to the redistribution of surface masses. The stability of our reference frame will be evaluated based on the obtained long-term trends of station coordinates, the load-induced deformation estimates and the homogeneous time series of station positions. We will compare our solution with other recent terrestrial reference system realizations and give some conclusions for future realizations of the ITRS.

Space and ground segment performance of the FORMOSAT-3/COSMIC mission: four years in orbit

NASA Astrophysics Data System (ADS)

Fong, C.-J.; Whiteley, D.; Yang, E.; Cook, K.; Chu, V.; Schreiner, B.; Ector, D.; Wilczynski, P.; Liu, T.-Y.; Yen, N.

2011-01-01

The FORMOSAT-3/COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) mission consisting of six Low-Earth-Orbit (LEO) satellites is the world's first demonstration constellation using radio occultation signals from Global Positioning System (GPS) satellites. The radio occultation signals are retrieved in near real-time for global weather/climate monitoring, numerical weather prediction, and space weather research. The mission has processed on average 1400 to 1800 high-quality atmospheric sounding profiles per day. The atmospheric radio occultation soundings data are assimilated into operational numerical weather prediction models for global weather prediction, including typhoon/hurricane/cyclone forecasts. The radio occultation data has shown a positive impact on weather predictions at many national weather forecast centers. A proposed follow-on mission transitions the program from the current experimental research system to a significantly improved real-time operational system, which will reliably provide 8000 radio occultation soundings per day. The follow-on mission as planned will consist of 12 satellites with a data latency of 45 min, which will provide greatly enhanced opportunities for operational forecasts and scientific research. This paper will address the FORMOSAT-3/COSMIC system and mission overview, the spacecraft and ground system performance after four years in orbit, the lessons learned from the encountered technical challenges and observations, and the expected design improvements for the new spacecraft and ground system.

A review of the global relationship among freshwater fish, autotrophic activity, and regional climate

USGS Publications Warehouse

Deines, Andrew M.; Bunnell, David B.; Rogers, Mark W.; Beard, T. Douglas; Taylor, William W.

2015-01-01

The relationship between autotrophic activity and freshwater fish populations is an important consideration for ecologists describing trophic structure in aquatic communities, fisheries managers tasked with increasing sustainable fisheries development, and fish farmers seeking to maximize production. Previous studies of the empirical relationships of autotrophic activity and freshwater fish yield have found positive relationships but were limited by small sample sizes, small geographic scopes, and the inability to compare patterns among many types of measurement techniques. Individual studies and reviews have also lacked consistent consideration of regional climate factors which may inform relationships between fisheries and autotrophic activity. We compiled data from over 700 freshwater systems worldwide and used meta-analysis and linear models to develop a comprehensive global synthesis between multiple metrics of autotrophic activity, fisheries, and climate indicators. Our results demonstrate that multiple metrics of fish (i.e., catch per unit effort, yield, and production) increase with autotrophic activity across a variety of fisheries. At the global scale additional variation in this positive relationship can be ascribed to regional climate differences (i.e., temperature and precipitation) across systems. Our results provide a method and proof-of-concept for assessing inland fisheries production at the global scale, where current estimates are highly uncertain, and may therefore inform the continued sustainable use of global inland fishery resources.

An Autonomous Distributed Fault-Tolerant Local Positioning System

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar R.

2017-01-01

We describe a fault-tolerant, GPS-independent (Global Positioning System) distributed autonomous positioning system for static/mobile objects and present solutions for providing highly-accurate geo-location data for the static/mobile objects in dynamic environments. The reliability and accuracy of a positioning system fundamentally depends on two factors; its timeliness in broadcasting signals and the knowledge of its geometry, i.e., locations and distances of the beacons. Existing distributed positioning systems either synchronize to a common external source like GPS or establish their own time synchrony using a scheme similar to a master-slave by designating a particular beacon as the master and other beacons synchronize to it, resulting in a single point of failure. Another drawback of existing positioning systems is their lack of addressing various fault manifestations, in particular, communication link failures, which, as in wireless networks, are increasingly dominating the process failures and are typically transient and mobile, in the sense that they typically affect different messages to/from different processes over time.

Yield response to variable rate irrigation in corn

USDA-ARS?s Scientific Manuscript database

To investigate the impact of variable rate irrigation on corn yield, twenty plots of corn were laid out under a center pivot variable rate irrigation (VRI) system in an experimental field near Stoneville, MS. The VRI system is equipped with five VRI zone control units, a global positioning system (G...

78 FR 48080 - Proposed Establishment of Class E Airspace; Magee, MS

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-07

...) Global Positioning System (GPS) Standard Instrument Approach Procedure (SIAP) serving Magee Municipal...) operations within the National Airspace System. DATES: Comments must be received on or before September 23... No. 13-ASO-8) and be submitted in triplicate to the Docket Management System (see ADDRESSES section...

Uses of GIS for Homeland Security and Emergency Management for Higher Education Institutions

ERIC Educational Resources Information Center

Murchison, Stuart B.

2010-01-01

Geographic information systems (GIS) are a major component of the geospatial sciences, which are also composed of geostatistical analysis, remote sensing, and global positional satellite systems. These systems can be integrated into GIS for georeferencing, pattern analysis, visualization, and understanding spatial concepts that transcend…

Contractor point of view for system development and test program

NASA Technical Reports Server (NTRS)

Koide, F. K.; Ringer, D. E.; Earl, C. E.

1981-01-01

Industry's practice of testing space qualified hardware is examined. An overview of the Global Positioning System (GPS) Test Program is discussed from the component level to the sub-system compatibility tests with the space vehicle and finally to the launch site tests, all related to the Rubidium clock.

Global dynamics of a delay differential equation with spatial non-locality in an unbounded domain

NASA Astrophysics Data System (ADS)

Yi, Taishan; Zou, Xingfu

In this paper, we study the global dynamics of a class of differential equations with temporal delay and spatial non-locality in an unbounded domain. Adopting the compact open topology, we describe the delicate asymptotic properties of the nonlocal delayed effect and establish some a priori estimate for nontrivial solutions which enables us to show the permanence of the equation. Combining these results with a dynamical systems approach, we determine the global dynamics of the equation under appropriate conditions. Applying the main results to the model with Ricker's birth function and Mackey-Glass's hematopoiesis function, we obtain threshold results for the global dynamics of these two models. We explain why our results on the global attractivity of the positive equilibrium in C∖{0} under the compact open topology becomes invalid in C∖{0} with respect to the usual supremum norm, and we identify a subset of C∖{0} in which the positive equilibrium remains attractive with respect to the supremum norm.

Indoor high precision three-dimensional positioning system based on visible light communication using modified genetic algorithm

NASA Astrophysics Data System (ADS)

Chen, Hao; Guan, Weipeng; Li, Simin; Wu, Yuxiang

2018-04-01

To improve the precision of indoor positioning and actualize three-dimensional positioning, a reversed indoor positioning system based on visible light communication (VLC) using genetic algorithm (GA) is proposed. In order to solve the problem of interference between signal sources, CDMA modulation is used. Each light-emitting diode (LED) in the system broadcasts a unique identity (ID) code using CDMA modulation. Receiver receives mixed signal from every LED reference point, by the orthogonality of spreading code in CDMA modulation, ID information and intensity attenuation information from every LED can be obtained. According to positioning principle of received signal strength (RSS), the coordinate of the receiver can be determined. Due to system noise and imperfection of device utilized in the system, distance between receiver and transmitters will deviate from the real value resulting in positioning error. By introducing error correction factors to global parallel search of genetic algorithm, coordinates of the receiver in three-dimensional space can be determined precisely. Both simulation results and experimental results show that in practical application scenarios, the proposed positioning system can realize high precision positioning service.

Characteristics of atmospheric gravity waves observed using the MU (Middle and Upper atmosphere) radar and GPS (Global Positioning System) radio occultation.

PubMed

Tsuda, Toshitaka

2014-01-01

The wind velocity and temperature profiles observed in the middle atmosphere (altitude: 10-100 km) show perturbations resulting from superposition of various atmospheric waves, including atmospheric gravity waves. Atmospheric gravity waves are known to play an important role in determining the general circulation in the middle atmosphere by dynamical stresses caused by gravity wave breaking. In this paper, we summarize the characteristics of atmospheric gravity waves observed using the middle and upper atmosphere (MU) radar in Japan, as well as novel satellite data obtained from global positioning system radio occultation (GPS RO) measurements. In particular, we focus on the behavior of gravity waves in the mesosphere (50-90 km), where considerable gravity wave attenuation occurs. We also report on the global distribution of gravity wave activity in the stratosphere (10-50 km), highlighting various excitation mechanisms such as orographic effects, convection in the tropics, meteorological disturbances, the subtropical jet and the polar night jet.

Characteristics of atmospheric gravity waves observed using the MU (Middle and Upper atmosphere) radar and GPS (Global Positioning System) radio occultation

PubMed Central

TSUDA, Toshitaka

2014-01-01

The wind velocity and temperature profiles observed in the middle atmosphere (altitude: 10–100 km) show perturbations resulting from superposition of various atmospheric waves, including atmospheric gravity waves. Atmospheric gravity waves are known to play an important role in determining the general circulation in the middle atmosphere by dynamical stresses caused by gravity wave breaking. In this paper, we summarize the characteristics of atmospheric gravity waves observed using the middle and upper atmosphere (MU) radar in Japan, as well as novel satellite data obtained from global positioning system radio occultation (GPS RO) measurements. In particular, we focus on the behavior of gravity waves in the mesosphere (50–90 km), where considerable gravity wave attenuation occurs. We also report on the global distribution of gravity wave activity in the stratosphere (10–50 km), highlighting various excitation mechanisms such as orographic effects, convection in the tropics, meteorological disturbances, the subtropical jet and the polar night jet. PMID:24492645

78 FR 33265 - Proposed Establishment of Class E Airspace; Umatilla, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-04

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at Umatilla Municipal Airport... (GPS) standard instrument approach procedures for Umatilla Municipal Airport. Controlled airspace...

The role of women's leadership and gender equity in leadership and health system strengthening.

PubMed

Dhatt, R; Theobald, S; Buzuzi, S; Ros, B; Vong, S; Muraya, K; Molyneux, S; Hawkins, K; González-Beiras, C; Ronsin, K; Lichtenstein, D; Wilkins, K; Thompson, K; Davis, K; Jackson, C

2017-01-01

Gender equity is imperative to the attainment of healthy lives and wellbeing of all, and promoting gender equity in leadership in the health sector is an important part of this endeavour. This empirical research examines gender and leadership in the health sector, pooling learning from three complementary data sources: literature review, quantitative analysis of gender and leadership positions in global health organisations and qualitative life histories with health workers in Cambodia, Kenya and Zimbabwe. The findings highlight gender biases in leadership in global health, with women underrepresented. Gender roles, relations, norms and expectations shape progression and leadership at multiple levels. Increasing women's leadership within global health is an opportunity to further health system resilience and system responsiveness. We conclude with an agenda and tangible next steps of action for promoting women's leadership in health as a means to promote the global goals of achieving gender equity.

Dynamical analysis of a cubic Liénard system with global parameters

NASA Astrophysics Data System (ADS)

Chen, Hebai; Chen, Xingwu

2015-10-01

In this paper we investigate the dynamical behaviour of a cubic Liénard system with global parameters. After analysing the qualitative properties of all the equilibria and judging the existences of limit cycles and homoclinic loops for the whole parameter plane, we give the bifurcation diagram and phase portraits. Phase portraits are global if there exist limit cycles and local otherwise. We prove that parameters lie in a connected region, not just on a curve, usually in the parameter plane when the system has one homoclinic loop. Moreover, for global parameters we give a positive answer to conjecture 3.2 of (1998 Nonlinearity 11 1505-19) in the case of exactly two equilibria about the existence of some function whose graph is exactly the surface of double limit cycles. Supported by NSFC 11471228, 11172246 and the Fundamental Research Funds for the Central Universities.

Efficient coding and detection of ultra-long IDs for visible light positioning systems.

PubMed

Zhang, Hualong; Yang, Chuanchuan

2018-05-14

Visible light positioning (VLP) is a promising technique to complement Global Navigation Satellite System (GNSS) such as Global positioning system (GPS) and BeiDou Navigation Satellite System (BDS) which features the advantage of low-cost and high accuracy. The situation becomes even more crucial for indoor environments, where satellite signals are weak or even unavailable. For large-scale application of VLP, there would be a considerable number of Light emitting diode (LED) IDs, which bring forward the demand of long LED ID detection. In particular, to provision indoor localization globally, a convenient way is to program a unique ID into each LED during manufacture. This poses a big challenge for image sensors, such as the CMOS camera in everybody's hands since the long ID covers the span of multiple frames. In this paper, we investigate the detection of ultra-long ID using rolling shutter cameras. By analyzing the pattern of data loss in each frame, we proposed a novel coding technique to improve the efficiency of LED ID detection. We studied the performance of Reed-Solomon (RS) code in this system and designed a new coding method which considered the trade-off between performance and decoding complexity. Coding technique decreases the number of frames needed in data processing, significantly reduces the detection time, and improves the accuracy of detection. Numerical and experimental results show that the detected LED ID can be much longer with the coding technique. Besides, our proposed coding method is proved to achieve a performance close to that of RS code while the decoding complexity is much lower.

Critical interactions between the Global Fund-supported HIV programs and the health system in Ghana.

PubMed

Atun, Rifat; Pothapregada, Sai Kumar; Kwansah, Janet; Degbotse, D; Lazarus, Jeffrey V

2011-08-01

The support of global health initiatives in recipient countries has been vigorously debated. Critics are concerned that disease-specific programs may be creating vertical and parallel service delivery structures that to some extent undermine health systems. This case study of Ghana aimed to explore how the Global Fund-supported HIV program interacts with the health system there and to map the extent and nature of integration of the national disease program across 6 key health systems functions. Qualitative interviews of national stakeholders were conducted to understand the perceptions of the strengths and weaknesses of the relationship between Global Fund-supported activities and the health system and to identify positive synergies and unintended consequences of integration. Ghana has a well-functioning sector-wide approach to financing its health system, with a strong emphasis on integrated care delivery. Ghana has benefited from US $175 million of approved Global Fund support to address the HIV epidemic, accounting for almost 85% of the National AIDS Control Program budget. Investments in infrastructure, human resources, and commodities have enabled HIV interventions to increase exponentially. Global Fund-supported activities have been well integrated into key health system functions to strengthen them, especially financing, planning, service delivery, and demand generation. Yet, with governance and monitoring and evaluation functions, parallel structures to national systems have emerged, leading to inefficiencies. This case study demonstrates that interactions and integration are highly varied across different health system functions, and strong government leadership has facilitated the integration of Global Fund-supported activities within national programs.

Diagnostic Accuracy of Global Pharma Health Fund Minilab™ in Assessing Pharmacopoeial Quality of Antimicrobials.

PubMed

Pan, Hui; Ba-Thein, William

2018-01-01

Global Pharma Health Fund (GPHF) Minilab™, a semi-quantitative thin-layer chromatography (TLC)-based commercially available test kit, is widely used in drug quality surveillance globally, but its diagnostic accuracy is unclear. We investigated the diagnostic accuracy of Minilab system for antimicrobials, using high-performance liquid chromatography (HPLC) as reference standard. Following the Minilab protocols and the Pharmacopoeia of the People's Republic of China protocols, Minilab-TLC and HPLC were used to test five common antimicrobials (506 batches) for relative concentration of active pharmaceutical ingredients. The prevalence of poor-quality antimicrobials determined, respectively, by Minilab TLC and HPLC was amoxicillin (0% versus 14.9%), azithromycin (0% versus 17.4%), cefuroxime axetil (14.3% versus 0%), levofloxacin (0% versus 3.0%), and metronidazole (0% versus 38.0%). The Minilab TLC had false-positive and false-negative detection rates of 2.6% (13/506) and 15.2% (77/506) accordingly, resulting in the following test characteristics: sensitivity 0%, specificity 97.0%, positive predictive value 0, negative predictive value 0.8, positive likelihood ratio 0, negative likelihood ratio 1.0, diagnostic odds ratio 0, and adjusted diagnostic odds ratio 0.2. This study demonstrates unsatisfying diagnostic accuracy of Minilab system in screening poor-quality antimicrobials of common use. Using Minilab as a stand-alone system for monitoring drug quality should be reconsidered.

Investigation of practical and theoretical accuracy of wireless indoor-positioning system UBISENSE

NASA Astrophysics Data System (ADS)

Wozniak, Marek; Odziemczyk, Waldemar; Nagorski, Kamil

2013-04-01

The development of Real Time Locating Systems has become an important add-on to many existing location aware systems. While Global Navigation Satelite System has solved most of the outdoor problems, it fails to repeat this success indoors. Wireless indoor positioning systems have become very popular in recent years. One of them is UBISENSE system. This system requires to carry an identity tag that is detected by sensors, which typically use triangulation to determine location. This paper presents the results of the investigation of accuracy of tag position using precise geodetic measurements and geometric analysis. Experimental measurements were carried out on the field polygon using precise tacheometer TCRP 1201+ and complete equipment of Ubisense. Results of experimental measurements were analyzed and presented graphically using Surfer 8. The paper presents the results of the investigation the teoretical and practical positioning accuracy according to the various working conditions.

Observability Analysis of a MEMS INS/GPS Integration System with Gyroscope G-Sensitivity Errors

PubMed Central

Fan, Chen; Hu, Xiaoping; He, Xiaofeng; Tang, Kanghua; Luo, Bing

2014-01-01

Gyroscopes based on micro-electromechanical system (MEMS) technology suffer in high-dynamic applications due to obvious g-sensitivity errors. These errors can induce large biases in the gyroscope, which can directly affect the accuracy of attitude estimation in the integration of the inertial navigation system (INS) and the Global Positioning System (GPS). The observability determines the existence of solutions for compensating them. In this paper, we investigate the observability of the INS/GPS system with consideration of the g-sensitivity errors. In terms of two types of g-sensitivity coefficients matrix, we add them as estimated states to the Kalman filter and analyze the observability of three or nine elements of the coefficient matrix respectively. A global observable condition of the system is presented and validated. Experimental results indicate that all the estimated states, which include position, velocity, attitude, gyro and accelerometer bias, and g-sensitivity coefficients, could be made observable by maneuvering based on the conditions. Compared with the integration system without compensation for the g-sensitivity errors, the attitude accuracy is raised obviously. PMID:25171122

Observability analysis of a MEMS INS/GPS integration system with gyroscope G-sensitivity errors.

PubMed

Fan, Chen; Hu, Xiaoping; He, Xiaofeng; Tang, Kanghua; Luo, Bing

2014-08-28

Gyroscopes based on micro-electromechanical system (MEMS) technology suffer in high-dynamic applications due to obvious g-sensitivity errors. These errors can induce large biases in the gyroscope, which can directly affect the accuracy of attitude estimation in the integration of the inertial navigation system (INS) and the Global Positioning System (GPS). The observability determines the existence of solutions for compensating them. In this paper, we investigate the observability of the INS/GPS system with consideration of the g-sensitivity errors. In terms of two types of g-sensitivity coefficients matrix, we add them as estimated states to the Kalman filter and analyze the observability of three or nine elements of the coefficient matrix respectively. A global observable condition of the system is presented and validated. Experimental results indicate that all the estimated states, which include position, velocity, attitude, gyro and accelerometer bias, and g-sensitivity coefficients, could be made observable by maneuvering based on the conditions. Compared with the integration system without compensation for the g-sensitivity errors, the attitude accuracy is raised obviously.

Evaluation of Design Assurance Regulations for Safety of Space Navigation Services

NASA Astrophysics Data System (ADS)

Ratti, B.; Sarno, M.; De Andreis, C.

2005-12-01

The European Space Agency (ESA), the European Community (EC), and the European Organisation for the Safety of Air Navigation (Eurocontrol) are contributing to the development of a Global positioning and Navigation Satellite System, known as GNSS. The development programme is carried out in two main steps:• GNSS-1: the first-generation system, based on signals received from the GPS (USA) and GLONASS (Russia) constellations, and augmentation systems like EGNOS (European Geostationary Navigation Overlay Service)• GNSS-2: the second-generation system, that will achieve the ultimate objective of European sovereignty for position determination, navigation and time dissemination. This system, named Galileo, comprises a global space and ground control infrastructure.The Galileo navigation signal will be used in the frame of safety-critical transport applications, thus it is necessary to assess the space safety assurance activity against the civil safety regulations and safety management system.. RTCA DO-254 and IEC 61508 standards, considered as part of best practice engineering references, for the development of safety- related systems in most applications, were selected during phases B2 and C0 of the Galileo project for this purpose.

Integrative freight demand management in the New York City metropolitan area.

DOT National Transportation Integrated Search

2010-09-01

This project is one of the first in the world that has successfully integrated the use of remote sensing : technologyin this case Global Positioning System (GPS) enabled cell phonesas part of a system that : effectively reduces truck traffic in...

FAA aircraft certification human factors and operations checklist for standalone GPS receivers (TSO C129 Class A)

DOT National Transportation Integrated Search

1995-04-01

This document is a checklist designed to assist Federal Aviation Administration(FAA) certification personnel and global : positioning system (GPS) receiver manufacturers in the evaluation of the pilot-system interface characteristlcs of GPS : recieve...

AIRS Impact on the Analysis and Forecast Track of Tropical Cyclone Nargis in a Global Data Assimilation and Forecasting System

NASA Technical Reports Server (NTRS)

Reale, O.; Lau, W.K.; Susskind, J.; Brin, E.; Liu, E.; Riishojgaard, L. P.; Rosenburg, R.; Fuentes, M.

2009-01-01

Tropical cyclones in the northern Indian Ocean pose serious challenges to operational weather forecasting systems, partly due to their shorter lifespan and more erratic track, compared to those in the Atlantic and the Pacific. Moreover, the automated analyses of cyclones over the northern Indian Ocean, produced by operational global data assimilation systems (DASs), are generally of inferior quality than in other basins. In this work it is shown that the assimilation of Atmospheric Infrared Sounder (AIRS) temperature retrievals under partial cloudy conditions can significantly impact the representation of the cyclone Nargis (which caused devastating loss of life in Myanmar in May 2008) in a global DAS. Forecasts produced from these improved analyses by a global model produce substantially smaller track errors. The impact of the assimilation of clear-sky radiances on the same DAS and forecasting system is positive, but smaller than the one obtained by ingestion of AIRS retrievals, possibly due to poorer coverage.

Mobile satellite communications in the 1990's

NASA Astrophysics Data System (ADS)

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.

Diatoms Si uptake capacity drives carbon export in coastal upwelling systems

NASA Astrophysics Data System (ADS)

Abrantes, Fatima; Cermeno, Pedro; Lopes, Cristina; Romero, Oscar; Matos, Lélia; Van Iperen, Jolanda; Rufino, Marta; Magalhães, Vitor

2016-07-01

Coastal upwelling systems account for approximately half of global ocean primary production and contribute disproportionately to biologically driven carbon sequestration. Diatoms, silica-precipitating microalgae, constitute the dominant phytoplankton in these productive regions, and their abundance and assemblage composition in the sedimentary record is considered one of the best proxies for primary production. The study of the sedimentary diatom abundance (SDA) and total organic carbon content (TOC) in the five most important coastal upwelling systems of the modern ocean (Iberia-Canary, Benguela, Peru-Humboldt, California, and Somalia-Oman) reveals a global-scale positive relationship between diatom production and organic carbon burial. The analysis of SDA in conjunction with environmental variables of coastal upwelling systems such as upwelling strength, satellite-derived net primary production, and surface water nutrient concentrations shows different relations between SDA and primary production on the regional scale. On the global scale, SDA appears modulated by the capacity of diatoms to take up silicic acid, which ultimately sets an upper limit to global export production in these ocean regions.

Monitoring of stability of ASG-EUPOS network coordinates

NASA Astrophysics Data System (ADS)

Figurski, M.; Szafranek, K.; Wrona, M.

2009-04-01

ASG-EUPOS (Active Geodetic Network - European Position Determination System) is the national system of precise satellite positioning in Poland, which increases a density of regional and global GNSS networks and is widely used by public administration, national institutions, entrepreneurs and citizens (especially surveyors). In near future ASG-EUPOS is to take role of main national network. Control of proper activity of stations and realization of ETRS'89 is a necessity. User of the system needs to be sure that observations quality and coordinates accuracy are high enough. Coordinates of IGS (International GNSS Service) and EPN (European Permanent Network) stations are precisely determined and any changes are monitored all the time. Observations are verified before they are archived in regional and global databases. The same applies to ASG-EUPOS. This paper concerns standardization of GNSS observations from different stations (uniform adjustment), examination of solutions correctness according to IGS and EPN standards and stability of solutions and sites activity

Global Positioning System offers evidence of plate motions in eastern Mediterranean

NASA Astrophysics Data System (ADS)

Burc Oral, M.; Reilinger, Robert E.; Nafi Toksöz, M.; King, Robert W.; Aykut Barka, A.; Kinik, Ibrahim; Lenk, Onur

Geophysicists are using the Global Positioning System (GPS), a highly precise satellite navigation system, to monitor the slow movements (cm/yr) of the crustal plates composing the Earth's surface and the deformations where such plates interact. We report the results of repeated GPS measurements in the complex zone of interaction between the Eurasian, Arabian, and African plates in Turkey. The GPS observations made between 1988 and 1992 indicate that western, central, and east central Turkey are decoupled from the Eurasian plate and are moving as a more or less coherent unit about an axis located north of the Sinai peninsula. Other space-based measurements of crustal motion in Greece and along the Hellenic arc [Smith et al., 1994] suggest that this coherent motion includes southern Greece and the south central Aegean Sea. We refer to this region (shaded in Figure 1) as the Anatolian plate.

Daily social interactions, close relationships, and systemic inflammation in two samples: Healthy middle-aged and older adults.

PubMed

Bajaj, Amoha; John-Henderson, Neha A; Cundiff, Jenny M; Marsland, Anna L; Manuck, Stephen B; Kamarck, Thomas W

2016-11-01

Systemic inflammation is thought to be a biological mediator between social relationship quality and premature mortality. Empirical work has yielded mixed support for an association of social relationship variables with systemic inflammation, perhaps due to methodological limitations. To date, research in this literature has focused on global perceptions of social relationships, with limited attention to the covariance of characteristics of daily social interactions with inflammation. Here, we examine whether daily interactions, as assessed by ecological momentary assessment (EMA), associate with peripheral markers of inflammation among midlife and older adults. Global social support and integration were measured using the Interpersonal Support Evaluation List (ISEL) and the Social Network Index (SNI), respectively, in older adults from the Pittsburgh Healthy Heart Project (PHHP), and in middle-aged adults from the Adult Health and Behavior Project-II (AHAB-II). Using time-sampled EMA, we assessed the proportion of the day spent in positive and negative social interactions. Systemic markers of inflammation were interleukin (IL)-6 and C-reactive protein (CRP). Global measures of support and integration did not associate with inflammation in either sample. In older adults, relative frequency of total positive interactions, those with close others (i.e. spouse, friends, family), and those with coworkers predicted lower concentrations of IL-6 in fully adjusted models, accounting for age, sex, race, education, BMI, smoking and alcohol. In middle-aged adults, relative frequency of positive interactions with close others was also inversely associated with IL-6 level and relative frequency of negative marital interactions was unexpectedly inversely associated with CRP level. Characteristics of daily social interactions among midlife and older adults associate with markers of systemic inflammation that are known to predict risk for cardiovascular disease. Ambulatory measures may better capture health-relevant social processes in daily life than retrospective, global self-report measures. Published by Elsevier Inc.

Anti-Jam GPS Antennas for Wearable Dismounted Soldier Navigation Systems

DTIC Science & Technology

2016-06-01

in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. Citation...Approaches for the design and fabrication of a wearable anti-jam global positioning system (GPS) antenna are explored to support accurate and uninterrupted...including GPS antenna element and array designs , and algorithms for jammer mitigation, and the candidate technologies best fit for wearable anti-jam GPS

A Business Case Analysis of Pre-Positioned Expeditionary Assistance Kit Joint Capability Technology Demonstration

DTIC Science & Technology

2013-12-01

of power from sunlight or a wind turbine (same solar panel tarps used in NEST Raptor Solar Light Trailer) • Global Positioning System (GPS) devices...satellite-enabled rapid wireless communications to the most critical areas and functions, working with Joint Task Forces. The first priority after the...a rapid response wireless communications system from military, civilian government, and non-government organizations. The tasks performed by HFN

Adaptive tracking control of a wheeled mobile robot via an uncalibrated camera system.

PubMed

Dixon, W E; Dawson, D M; Zergeroglu, E; Behal, A

2001-01-01

This paper considers the problem of position/orientation tracking control of wheeled mobile robots via visual servoing in the presence of parametric uncertainty associated with the mechanical dynamics and the camera system. Specifically, we design an adaptive controller that compensates for uncertain camera and mechanical parameters and ensures global asymptotic position/orientation tracking. Simulation and experimental results are included to illustrate the performance of the control law.

Index to Army Times 1991

DTIC Science & Technology

1992-08-01

AIRCRAFT) Winging it. Army Times; Oct. 14, 1991; 52(11): p. 26. AAC SEE ARMY ACQUISITION CORPS (AAC) AAFES SEE ARMY AND AIR FORCE EXCHANGE SERVICE (AAFES...allies in Germany. Army Times; Sept. 23, 1991; 52(8): p. 10. GLOBAL POSITIONING SYSTEM (GPS) SEE OPERATION DESERT STORK , 1991--GLOSAL POSITIONING SYSTEM (G...COMPETITIONS Golden Knights triumph. Army Times; Oct. 28, 1991; 52(13): p. 14. GOVERNMENT ACCOUNTING OFFICE (GAO)--AUOIT--HELICOPTERS Republicans move to clip

Individual Global Navigation Satellite Systems in the Space Service Volume

NASA Technical Reports Server (NTRS)

Force, Dale A.

2013-01-01

The use of individual Global Navigation Satellite Services (GPS, GLONASS, Galileo, and Beidou/COMPASS) for the position, navigation, and timing in the Space Service Volume at altitudes of 300 km, 3000 km, 8000 km, 15000 km, 25000 km, 36500km and 70000 km is examined and the percent availability of at least one and at least four satellites is presented.

GPS Data Analysis for Earth Orientation at the Jet Propulsion Laboratory

NASA Technical Reports Server (NTRS)

Zumberge, J.; Webb, F.; Lindqwister, U.; Lichten, S.; Jefferson, D.; Ibanez-Meier, R.; Heflin, M.; Freedman, A.; Blewitt, G.

1994-01-01

Beginning June 1992 and continuing indefinitely as part of our contribution to FLINN (Fiducial Laboratories for an International Natural Science Network), DOSE (NASA's Dynamics of the Solid Earth Program), and the IGS (International GPS Geodynamics Service), analysts at the Jet Propulsion Laboratory (JPL) have routinely been reducing data from a globally-distributed network of Rogue Global Positioning System (GPS) receivers.

How Neoliberal Globalization Is Shaping Early Childhood Education Policies in India, China, Singapore, Sri Lanka and the Maldives

ERIC Educational Resources Information Center

Gupta, Amita

2018-01-01

In rapidly globalizing systems of schooling around the world, economic considerations have led to a push to impose neoliberal reforms in the field of education. Under this influence early childhood education and teacher education in Asia have increasingly become positioned as regulated markets governed by neoliberal policies, leading to peak…

Location of geographical objects in crisis situations

NASA Astrophysics Data System (ADS)

Rybansky, M.; Kratochvil, V.

2014-02-01

This article summarizes the various expressions of object positioning using different coordinate data and different methods, such as use of maps, exploiting the properties of digital Global System for Mobile Communications (GSM) networks, Global Navigational Satellite Systems (GNSS), Inertial Navigation Systems (INS), Inertial Measurement Systems (IMS), hybrid methods and non-contact (remote sensing) methods; all with varying level of accuracy. Furthermore, the article describes some geographical identifiers and verbal means to describe location of geographical objects such as settlements, rivers, forest, roads, etc. All of the location methods have some advantages and disadvantages, especially in emergency situations, when usually the crisis management has a lack of time in a decision process.

Test results of the STI GPS time transfer receiver

NASA Technical Reports Server (NTRS)

Hall, D. L.; Handlan, J.; Wheeler, P.

1983-01-01

Global time transfer, or synchronization, between a user clock and USNO UTC time can be performed using the Global Positioning System (GPS), and commercially available time transfer receivers. This paper presents the test results of time transfer using the GPS system and a Stanford Telecommunications, Inc. (STI) Time Transfer System (TTS) Model 502. Tests at the GPS Master Control Site (MCS) in Vandenburg, California and at the United States Naval Observatory (USNO) in Washington, D.C. are described. An overview of GPS, and the STI TTS 502 is presented. A discussion of the time transfer process and test concepts is included.

Realizing a terrestrial reference frame using the Global Positioning System

NASA Astrophysics Data System (ADS)

Haines, Bruce J.; Bar-Sever, Yoaz E.; Bertiger, Willy I.; Desai, Shailen D.; Harvey, Nate; Sibois, Aurore E.; Weiss, Jan P.

2015-08-01

We describe a terrestrial reference frame (TRF) realization based on Global Positioning System (GPS) data alone. Our approach rests on a highly dynamic, long-arc (9 day) estimation strategy and on GPS satellite antenna calibrations derived from Gravity Recovery and Climate Experiment and TOPEX/Poseidon low Earth orbit receiver GPS data. Based on nearly 17 years of data (1997-2013), our solution for scale rate agrees with International Terrestrial Reference Frame (ITRF)2008 to 0.03 ppb yr-1, and our solution for 3-D origin rate agrees with ITRF2008 to 0.4 mm yr-1. Absolute scale differs by 1.1 ppb (7 mm at the Earth's surface) and 3-D origin by 8 mm. These differences lie within estimated error levels for the contemporary TRF.

Coastal bathymetry data collected in May 2015 from Fire Island, New York—Wilderness breach and shoreface

USGS Publications Warehouse

Nelson, Timothy R.; Miselis, Jennifer L.; Hapke, Cheryl J.; Brenner, Owen T.; Henderson, Rachel E.; Reynolds, Billy J.; Wilson, Kathleen E.

2017-05-12

Scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, conducted a bathymetric survey of Fire Island from May 6-20, 2015. The USGS is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the wilderness breach as a part of the Hurricane Sandy Supplemental Project GS2-2B. During this study, bathymetry data were collected with single-beam echo sounders and Global Positioning Systems, which were mounted to personal watercraft, along the Fire Island shoreface and within the wilderness breach. Additional bathymetry and elevation data were collected using backpack Global Positioning Systems on flood shoals and in shallow channels within the wilderness breach.

Strongly-motivated positive affects induce faster responses to local than global information of visual stimuli: an approach using large-size Navon letters.

PubMed

Noguchi, Yasuki; Tomoike, Kouta

2016-01-12

Recent studies argue that strongly-motivated positive emotions (e.g. desire) narrow a scope of attention. This argument is mainly based on an observation that, while humans normally respond faster to global than local information of a visual stimulus (global advantage), positive affects eliminated the global advantage by selectively speeding responses to local (but not global) information. In other words, narrowing of attentional scope was indirectly evidenced by the elimination of global advantage (the same speed of processing between global and local information). No study has directly shown that strongly-motivated positive affects induce faster responses to local than global information while excluding a bias for global information (global advantage) in a baseline (emotionally-neutral) condition. In the present study, we addressed this issue by eliminating the global advantage in a baseline (neutral) state. Induction of positive affects under this state resulted in faster responses to local than global information. Our results provided direct evidence that positive affects in high motivational intensity narrow a scope of attention.

Position Estimation and Local Mapping Using Omnidirectional Images and Global Appearance Descriptors

PubMed Central

Berenguer, Yerai; Payá, Luis; Ballesta, Mónica; Reinoso, Oscar

2015-01-01

This work presents some methods to create local maps and to estimate the position of a mobile robot, using the global appearance of omnidirectional images. We use a robot that carries an omnidirectional vision system on it. Every omnidirectional image acquired by the robot is described only with one global appearance descriptor, based on the Radon transform. In the work presented in this paper, two different possibilities have been considered. In the first one, we assume the existence of a map previously built composed of omnidirectional images that have been captured from previously-known positions. The purpose in this case consists of estimating the nearest position of the map to the current position of the robot, making use of the visual information acquired by the robot from its current (unknown) position. In the second one, we assume that we have a model of the environment composed of omnidirectional images, but with no information about the location of where the images were acquired. The purpose in this case consists of building a local map and estimating the position of the robot within this map. Both methods are tested with different databases (including virtual and real images) taking into consideration the changes of the position of different objects in the environment, different lighting conditions and occlusions. The results show the effectiveness and the robustness of both methods. PMID:26501289

Drop Out Patterns in the East Los Angeles Community College

ERIC Educational Resources Information Center

Waktola, Daniel K.

2014-01-01

This study attempted to analyze the drop out problem from spatial perspectives within the context of East Los Angeles Community College, California. Selected urban land-use types, which positively and negatively influence the propensity to drop out or persist-in colleges, were selected and captured during a global positioning system (GPS)-based…

Components of spatial information management in wildlife ecology: Software for statistical and modeling analysis [Chapter 14

Treesearch

Hawthorne L. Beyer; Jeff Jenness; Samuel A. Cushman

2010-01-01

Spatial information systems (SIS) is a term that describes a wide diversity of concepts, techniques, and technologies related to the capture, management, display and analysis of spatial information. It encompasses technologies such as geographic information systems (GIS), global positioning systems (GPS), remote sensing, and relational database management systems (...

Launch vehicle tracking enhancement through Global Positioning System Metric Tracking

NASA Astrophysics Data System (ADS)

Moore, T. C.; Li, Hanchu; Gray, T.; Doran, A.

United Launch Alliance (ULA) initiated operational flights of both the Atlas V and Delta IV launch vehicle families in 2002. The Atlas V and Delta IV launch vehicles were developed jointly with the US Air Force (USAF) as part of the Evolved Expendable Launch Vehicle (EELV) program. Both Launch Vehicle (LV) families have provided 100% mission success since their respective inaugural launches and demonstrated launch capability from both Vandenberg Air Force Base (VAFB) on the Western Test Range and Cape Canaveral Air Force Station (CCAFS) on the Eastern Test Range. However, the current EELV fleet communications, tracking, & control architecture & technology, which date back to the origins of the space launch business, require support by a large and high cost ground footprint. The USAF has embarked on an initiative known as Future Flight Safety System (FFSS) that will significantly reduce Test Range Operations and Maintenance (O& M) cost by closing facilities and decommissioning ground assets. In support of the FFSS, a Global Positioning System Metric Tracking (GPS MT) System based on the Global Positioning System (GPS) satellite constellation has been developed for EELV which will allow both Ranges to divest some of their radar assets. The Air Force, ULA and Space Vector have flown the first 2 Atlas Certification vehicles demonstrating the successful operation of the GPS MT System. The first Atlas V certification flight was completed in February 2012 from CCAFS, the second Atlas V certification flight from VAFB was completed in September 2012 and the third certification flight on a Delta IV was completed October 2012 from CCAFS. The GPS MT System will provide precise LV position, velocity and timing information that can replace ground radar tracking resource functionality. The GPS MT system will provide an independent position/velocity S-Band telemetry downlink to support the current man-in-the-loop ground-based commanded destruct of an anomalous flight- The system utilizes a 50 channel digital receiver capable of navigating in high dynamic environments and high altitudes fed by antennas mounted diametrically opposed on the second stage airframe skin. To enhance cost effectiveness, the GPS MT System design implemented existing commercial parts and common environmental and interface requirements for both EELVs. The EELV GPS MT System design is complete, successfully qualified and has demonstrated that the system performs as simulated. This paper summarizes the current development status, system cost comparison, and performance capabilities of the EELV GPS MT System.

Extended investigation into continuous laser scanning of underground mine workings by means of Landis inertial navigation system

NASA Astrophysics Data System (ADS)

Belyaev, E. N.

2017-10-01

The paper investigates the method of applying mobile scanning systems (MSSs) with inertial navigators in the underground conditions for carrying out the surveying tasks. The available mobile laser scanning systems cannot be used in the underground environment since Global Positioning System (GPS) signals cannot be received in mines. This signal not only is necessary for space positioning, but also operates as the main corrective signal for the primary navigation system - the inertial navigation system. The idea of the method described in this paper consists in using MSSs with a different correction of the inertial system than GPS is.

A New Position Location System Using DTV Transmitter Identification Watermark Signals

NASA Astrophysics Data System (ADS)

Wang, Xianbin; Wu, Yiyan; Chouinard, Jean-Yves

2006-12-01

A new position location technique using the transmitter identification (TxID) RF watermark in the digital TV (DTV) signals is proposed in this paper. Conventional global positioning system (GPS) usually does not work well inside buildings due to the high frequency and weak field strength of the signal. In contrast to the GPS, the DTV signals are received from transmitters at relatively short distance, while the broadcast transmitters operate at levels up to the megawatts effective radiated power (ERP). Also the RF frequency of the DTV signal is much lower than the GPS, which makes it easier for the signal to penetrate buildings and other objects. The proposed position location system based on DTV TxID signal is presented in this paper. Practical receiver implementation issues including nonideal correlation and synchronization are analyzed and discussed. Performance of the proposed technique is evaluated through Monte Carlo simulations and compared with other existing position location systems. Possible ways to improve the accuracy of the new position location system is discussed.

Office of Space Flight standard spaceborne Global Positioning System user equipment project

NASA Technical Reports Server (NTRS)

Saunders, Penny E.

1991-01-01

The Global Positioning System (GPS) provides users autonomous, real-time navigation capability. A vehicle equipped with GPS user equipment can receive and process signals transmitted by a constellation of GPS satellites and derive from the resulting measurements the vehicle's position and velocity. Specified accuracies range from 16 to 76 meters and 0.1 to 1.0 meters/second for position and velocity, respectively. In a rendezvous and docking scenario, the use of a technique called relative GPS can provide range and range rate accuracies on the order of 1 meter and 0.01 meters/second, respectively. Relative GPS requires both vehicles to be equipped with GPS user equipment and a data communication link for transmission of GPS data and GPS satellite selection coordination information. Through coordinated satellite selection, GPS measurement errors common to both users are cancelled and improved relative position and velocity accuracies are achieved. The background, the design approach, the expected performance and capabilities, the development plan, and the project status are described. In addition, a description of relative GPS, the possible GPS hardware and software configurations, and its application to automated rendezvous and capture are presented.

Global Positioning System Disaster Notification Messaging Service

DTIC Science & Technology

2013-09-01

under AT&T service. Differing combinations of phone operating system types and versions (Android, iOS, Windows 8, Blackberry OS, et al.) service...streets, tunnels and subways. Substantial damage was incurred along the Atlantic coasts of both states with sustained power outages. As the storm’s

Oregon regional intelligent transportation systems (ITS) integration program. Final phase III report, transit tracker information displays

DOT National Transportation Integrated Search

2003-11-14

Transit Tracker uses global positioning system (GPS) technology to track how far a bus is along its scheduled route. This document presents the evaluation strategies and objectives, the data collection methodologies, and the results of the evaluation...

77 FR 45240 - Establishment of Class E Airspace; Quakertown, PA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-31

... at Quakertown, PA, to accommodate the new Area Navigation (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedures at Quakertown Airport. This action enhances the safety and airspace management of Instrument Flight Rules (IFR) operations within the National Airspace System. [[Page 45241...

77 FR 33685 - Proposed Establishment of Class E Airspace; Arcadia, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-07

... action proposes to establish Class E Airspace at Arcadia, FL, to accommodate the Area Navigation (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedures at Arcadia Municipal Airport... Proposed Rulemaking distribution System, which describes the application procedure. The Proposal The FAA is...

77 FR 45241 - Establishment of Class E Airspace; Apopka, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-31

... at Apopka, FL, to accommodate the new Area Navigation (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedures at Orlando Apopka Airport. This action enhances the safety and airspace management of Instrument Flight Rules (IFR) operations within the National Airspace System. DATES: Effective...

77 FR 45240 - Establishment of Class E Airspace; Arcadia, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-31

... at Arcadia, FL, to accommodate the new Area Navigation (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedures at Arcadia Municipal Airport. This action enhances the safety and airspace management of Instrument Flight Rules (IFR) operations within the National Airspace System. DATES...

Remote sensing for detecting and mapping whitefly (Bemisia tabaci) infestations

USDA-ARS?s Scientific Manuscript database

Remote sensing technology has long been used for detecting insect infestations on agricultural crops. With recent advances in remote sensing sensors and other spatial information technologies such as Global Position Systems (GPS) and Geographic Information Systems (GIS), remote sensing is finding mo...

Spacecraft applications of advanced global positioning system technology

NASA Technical Reports Server (NTRS)

1988-01-01

This is the final report on the Texas Instruments Incorporated (TI) simulations study of Spacecraft Application of Advanced Global Positioning System (GPS) Technology. This work was conducted for the NASA Johnson Space Center (JSC) under contract NAS9-17781. GPS, in addition to its baselined capability as a highly accurate spacecraft navigation system, can provide traffic control, attitude control, structural control, and uniform time base. In Phase 1 of this program, another contractor investigated the potential of GPS in these four areas and compared GPS to other techniques. This contract was for the Phase 2 effort, to study the performance of GPS for these spacecraft applications through computer simulations. TI had previously developed simulation programs for GPS differential navigation and attitude measurement. These programs were adapted for these specific spacecraft applications. In addition, TI has extensive expertise in the design and production of advanced GPS receivers, including space-qualified GPS receivers. We have drawn on this background to augment the simulation results in the system level overview, which is Section 2 of this report.

Maintenance of time and frequency in the Jet Propulsion Laboratory's Deep Space Network using the Global Positioning System

NASA Technical Reports Server (NTRS)

Clements, P. A.; Borutzki, S. E.; Kirk, A.

1984-01-01

The Deep Space Network (DSN), managed by the Jet Propulsion Laboratory for NASA, must maintain time and frequency within specified limits in order to accurately track the spacecraft engaged in deep space exploration. Various methods are used to coordinate the clocks among the three tracking complexes. These methods include Loran-C, TV Line 10, Very Long Baseline Interferometry (VLBI), and the Global Positioning System (GPS). Calculations are made to obtain frequency offsets and Allan variances. These data are analyzed and used to monitor the performance of the hydrogen masers that provide the reference frequencies for the DSN Frequency and Timing System (DFT). Areas of discussion are: (1) a brief history of the GPS timing receivers in the DSN, (2) a description of the data and information flow, (3) data on the performance of the DSN master clocks and GPS measurement system, and (4) a description of hydrogen maser frequency steering using these data.

Localization Based on Magnetic Markers for an All-Wheel Steering Vehicle

PubMed Central

Byun, Yeun Sub; Kim, Young Chol

2016-01-01

Real-time continuous localization is a key technology in the development of intelligent transportation systems. In these systems, it is very important to have accurate information about the position and heading angle of the vehicle at all times. The most widely implemented methods for positioning are the global positioning system (GPS), vision-based system, and magnetic marker system. Among these methods, the magnetic marker system is less vulnerable to indoor and outdoor environment conditions; moreover, it requires minimal maintenance expenses. In this paper, we present a position estimation scheme based on magnetic markers and odometry sensors for an all-wheel-steering vehicle. The heading angle of the vehicle is determined by using the position coordinates of the last two detected magnetic markers and odometer data. The instant position and heading angle of the vehicle are integrated with an extended Kalman filter to estimate the continuous position. GPS data with the real-time kinematics mode was obtained to evaluate the performance of the proposed position estimation system. The test results show that the performance of the proposed localization algorithm is accurate (mean error: 3 cm; max error: 9 cm) and reliable under unexpected missing markers or incorrect markers. PMID:27916827

Using Mobile Learning to Improve the Reflection: A Case Study of Traffic Violation

ERIC Educational Resources Information Center

Lan, Yu-Feng; Huang, Shin-Ming

2012-01-01

The purpose of this study was to integrate mobile communication technologies and a global positioning system (GPS) to construct an instant, convenient report of the mobile network service system named the Mobile Traffic Violation Reporting System (MTVRS), to improve learners' traffic violation reflection level. Data were collected using a…

Joint University Program for Air Transportation Research, 1985

NASA Technical Reports Server (NTRS)

Morrell, Frederick R. (Compiler)

1987-01-01

Air transportation research being carried on at the Massachusetts Institute of Technology, Princeton University, and Ohio University is discussed. Global Positioning System experiments, Loran-C monitoring, inertial navigation, the optimization of aircraft trajectories through severe microbursts, fault tolerant flight control systems, and expert systems for air traffic control are among the topics covered.

Geographical Information Systems (GIS) Mapping of Environmental Samples across College Campuses

ERIC Educational Resources Information Center

Purvis-Roberts, Kathleen L.; Moeur, Harriet P.; Zanella, Andrew

2007-01-01

In this laboratory experiment, students take environmental samples at various locations around the college campuses, take geospatial coordinates with a global position systems (GPS) unit, and map their results on a geo-referenced campus map with geographical information systems (GIS) software. Nitrogen dioxide air pollution sampling is used as an…

Navigation and Landing Transition Strategy

DOT National Transportation Integrated Search

2002-08-01

Attached is the Federal Aviation Administration's (FAA) Navigation and Landing Transition Strategy. This report defines the satellite navigation transition strategy that considers the vulnerability of the Global Positioning System (GPS) and describes...

GPS Software Packages Deliver Positioning Solutions

NASA Technical Reports Server (NTRS)

2010-01-01

"To determine a spacecraft s position, the Jet Propulsion Laboratory (JPL) developed an innovative software program called the GPS (global positioning system)-Inferred Positioning System and Orbit Analysis Simulation Software, abbreviated as GIPSY-OASIS, and also developed Real-Time GIPSY (RTG) for certain time-critical applications. First featured in Spinoff 1999, JPL has released hundreds of licenses for GIPSY and RTG, including to Longmont, Colorado-based DigitalGlobe. Using the technology, DigitalGlobe produces satellite imagery with highly precise latitude and longitude coordinates and then supplies it for uses within defense and intelligence, civil agencies, mapping and analysis, environmental monitoring, oil and gas exploration, infrastructure management, Internet portals, and navigation technology."

GNSS global real-time augmentation positioning: Real-time precise satellite clock estimation, prototype system construction and performance analysis

NASA Astrophysics Data System (ADS)

Chen, Liang; Zhao, Qile; Hu, Zhigang; Jiang, Xinyuan; Geng, Changjiang; Ge, Maorong; Shi, Chuang

2018-01-01

Lots of ambiguities in un-differenced (UD) model lead to lower calculation efficiency, which isn't appropriate for the high-frequency real-time GNSS clock estimation, like 1 Hz. Mixed differenced model fusing UD pseudo-range and epoch-differenced (ED) phase observations has been introduced into real-time clock estimation. In this contribution, we extend the mixed differenced model for realizing multi-GNSS real-time clock high-frequency updating and a rigorous comparison and analysis on same conditions are performed to achieve the best real-time clock estimation performance taking the efficiency, accuracy, consistency and reliability into consideration. Based on the multi-GNSS real-time data streams provided by multi-GNSS Experiment (MGEX) and Wuhan University, GPS + BeiDou + Galileo global real-time augmentation positioning prototype system is designed and constructed, including real-time precise orbit determination, real-time precise clock estimation, real-time Precise Point Positioning (RT-PPP) and real-time Standard Point Positioning (RT-SPP). The statistical analysis of the 6 h-predicted real-time orbits shows that the root mean square (RMS) in radial direction is about 1-5 cm for GPS, Beidou MEO and Galileo satellites and about 10 cm for Beidou GEO and IGSO satellites. Using the mixed differenced estimation model, the prototype system can realize high-efficient real-time satellite absolute clock estimation with no constant clock-bias and can be used for high-frequency augmentation message updating (such as 1 Hz). The real-time augmentation message signal-in-space ranging error (SISRE), a comprehensive accuracy of orbit and clock and effecting the users' actual positioning performance, is introduced to evaluate and analyze the performance of GPS + BeiDou + Galileo global real-time augmentation positioning system. The statistical analysis of real-time augmentation message SISRE is about 4-7 cm for GPS, whlile 10 cm for Beidou IGSO/MEO, Galileo and about 30 cm for BeiDou GEO satellites. The real-time positioning results prove that the GPS + BeiDou + Galileo RT-PPP comparing to GPS-only can effectively accelerate convergence time by about 60%, improve the positioning accuracy by about 30% and obtain averaged RMS 4 cm in horizontal and 6 cm in vertical; additionally RT-SPP accuracy in the prototype system can realize positioning accuracy with about averaged RMS 1 m in horizontal and 1.5-2 m in vertical, which are improved by 60% and 70% to SPP based on broadcast ephemeris, respectively.

Global Coordinates and Exact Aberration Calculations Applied to Physical Optics Modeling of Complex Optical Systems

NASA Astrophysics Data System (ADS)

Lawrence, G.; Barnard, C.; Viswanathan, V.

1986-11-01

Historically, wave optics computer codes have been paraxial in nature. Folded systems could be modeled by "unfolding" the optical system. Calculation of optical aberrations is, in general, left for the analyst to do with off-line codes. While such paraxial codes were adequate for the simpler systems being studied 10 years ago, current problems such as phased arrays, ring resonators, coupled resonators, and grazing incidence optics require a major advance in analytical capability. This paper describes extension of the physical optics codes GLAD and GLAD V to include a global coordinate system and exact ray aberration calculations. The global coordinate system allows components to be positioned and rotated arbitrarily. Exact aberrations are calculated for components in aligned or misaligned configurations by using ray tracing to compute optical path differences and diffraction propagation. Optical path lengths between components and beam rotations in complex mirror systems are calculated accurately so that coherent interactions in phased arrays and coupled devices may be treated correctly.

Expedite random structure searching using objects from Wyckoff positions

NASA Astrophysics Data System (ADS)

Wang, Shu-Wei; Hsing, Cheng-Rong; Wei, Ching-Ming

2018-02-01

Random structure searching has been proved to be a powerful approach to search and find the global minimum and the metastable structures. A true random sampling is in principle needed yet it would be highly time-consuming and/or practically impossible to find the global minimum for the complicated systems in their high-dimensional configuration space. Thus the implementations of reasonable constraints, such as adopting system symmetries to reduce the independent dimension in structural space and/or imposing chemical information to reach and relax into low-energy regions, are the most essential issues in the approach. In this paper, we propose the concept of "object" which is either an atom or composed of a set of atoms (such as molecules or carbonates) carrying a symmetry defined by one of the Wyckoff positions of space group and through this process it allows the searching of global minimum for a complicated system to be confined in a greatly reduced structural space and becomes accessible in practice. We examined several representative materials, including Cd3As2 crystal, solid methanol, high-pressure carbonates (FeCO3), and Si(111)-7 × 7 reconstructed surface, to demonstrate the power and the advantages of using "object" concept in random structure searching.

Global positioning system and associated technologies in animal behaviour and ecological research

PubMed Central

Tomkiewicz, Stanley M.; Fuller, Mark R.; Kie, John G.; Bates, Kirk K.

2010-01-01

Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS ‘rapid fixing’ technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives. PMID:20566494

Global positioning system and associated technologies in animal behaviour and ecological research

USGS Publications Warehouse

Tomkiewicz, Stanley M.; Fuller, Mark R.; Kie, John G.; Bates, Kirk K.

2010-01-01

Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS 'rapid fixing' technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives.

A time for new north–south relationships in global health

PubMed Central

Kim, Jin Un; Oleribe, Obinna; Njie, Ramou; Taylor-Robinson, Simon D

2017-01-01

The modern concept of globalization in health care and clinical research often carries a positive message for the “Global South” nations of Africa, South America and Southeast Asia. However, bioethical abuse of participants in clinical trials still exists in the Global South. Unethical studies directed by the “Global North”, formed by the medically advanced nations in North America, Western Europe and Japan, have been hugely concerning. The issue between the Global North and South is a well-recognized socioeconomic phenomenon of globalization. Medical exploitation has its roots in the socioeconomic interactions of a postcolonial world, and solutions to reducing exploitation require a deeper understanding of these societal models of globalization. We explore the fundamental causes of imbalance and suggest solutions. Reflecting on the globalization model, there must be an effort to empower the Global South nations to direct and govern their own health care systems efficiently on the basis of equality. PMID:29158688

Helicopter Approach Capability Using the Differential Global Positioning System

NASA Technical Reports Server (NTRS)

Kaufmann, David N.

1994-01-01

The results of flight tests to determine the feasibility of using the Global Positioning System (GPS) in the Differential mode (DGPS) to provide high accuracy, precision navigation and guidance for helicopter approaches to landing are presented. The airborne DGPS receiver and associated equipment is installed in a NASA UH-60 Black Hawk helicopter. The ground-based DGPS reference receiver is located at a surveyed test site and is equipped with a real-time VHF data link to transmit correction information to the airborne DGPS receiver. The corrected airborne DGPS information, together with the preset approach geometry, is used to calculate guidance commands which are sent to the aircraft's approach guidance instruments. The use of DGPS derived guidance for helicopter approaches to landing is evaluated by comparing the DGPS data with the laser tracker truth data. The errors indicate that the helicopter position based on DGPS guidance satisfies the International Civil Aviation Organization (ICAO) Category 1 (CAT 1) lateral and vertical navigational accuracy requirements.

LADOTD GPS technology management plan.

DOT National Transportation Integrated Search

2012-02-01

Over many years, Global Positioning System (GPS) technology has been adopted by different sections within the Louisiana : Department of Transportation and Development (DOTD), with no uniform standards for accuracy, operation, hardware, or : software....

Vulnerabilities of the Global Positioning System and the Impact on the Iron Triad: The AWACS, JSTARS, and Rivet Joint Fleets

DTIC Science & Technology

2010-06-11

capable of two-dimensional position information; they only provided latitude and longitude. This was not a significant problem for surface vessels...reliable three-dimensional navigation capable of providing continuous latitude , longitude and altitude information. Additionally, the Air Force’s system...upgrade initiatives for both AWACS and JSTARS airframes, consider the DRAGON program a model to modernize other Triad aircraft to comply with CNS/ATM

Local Geoid Determination Using the Global Positioning System

DTIC Science & Technology

1988-09-01

Positioning System by Ma, Wei-Ming September 1988 Co-Advisor: Kandiah Jeyapalan Co-Advisor: Stevens P. Tucker Approved for public release; distribution is... Jeyapalan and Stevens P. Tucker, my thesis advisors, for their dedicated assistance and guidance during the study. Without their encouragement...method of collocation is [ Jeyapalan , 1977]: x = A*X+S +n +O.S q q P where x the vector of the observation (x = Ah - N0(X,Y,Z) - H) A a given rectangular

78 FR 25384 - Establishment of Class E Airspace; Immokalee, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-01

... management of Instrument Flight Rules (IFR) operations within the National Airspace System. DATES: Effective... at Immokalee, FL, to accommodate the Area Navigation (RNAV) Global Positioning System (GPS) Standard... Procedures developed for Big Cypress Airfield. This action is necessary for the safety and management of IFR...

76 FR 34196 - Proposed Establishment of Class E Airspace; Forest, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-13

...) Global Positioning System (GPS) Standard Instrument Approach Procedures serving New London Airport. This action would enhance the safety and airspace management of Instrument Flight Rules (IFR) operations...; Airspace Docket No. 11-AEA-11) and be submitted in triplicate to the Docket Management System (see...

78 FR 14473 - Proposed Establishment of Class E Airspace; Sanibel, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-06

...) Global Positioning System (GPS) special Standard Instrument Approach Procedure (SIAP) serving Sanibel Island Heliport. This action would enhance the safety and airspace management of Instrument Flight Rules...; Airspace Docket No. 12-ASO-18) and be submitted in triplicate to the Docket Management System (see...

76 FR 54155 - Proposed Establishment of Class E Airspace; Danville, PA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-31

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at Danville Airport. This action would enhance the safety and airspace management of Instrument Flight Rules (IFR) operations at the... submitted in triplicate to the Docket Management System (see ADDRESSES section for address and phone number...

78 FR 14475 - Proposed Establishment of Class E Airspace; Cleveland, TN

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-06

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at Cleveland Regional Jetport. This action would enhance the safety and airspace management of Instrument Flight Rules (IFR...; Airspace Docket No. 12-ASO-47) and be submitted in triplicate to the Docket Management System (see...

76 FR 35370 - Proposed Establishment of Class E Airspace; Copperhill, TN

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-17

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at Martin Campbell Field Airport. This action would enhance the safety and airspace management of Instrument Flight Rules (IFR... submitted in triplicate to the Docket Management System (see ADDRESSES section for address and phone number...

Geospatial Technologies and Higher Education in Argentina

ERIC Educational Resources Information Center

Leguizamon, Saturnino

2010-01-01

The term "geospatial technologies" encompasses a large area of fields involving cartography, spatial analysis, geographic information system, remote sensing, global positioning systems and many others. These technologies should be expected to be available (as "natural tools") for a country with a large surface and a variety of…

University Rankings as Instruments for the Reform of the System of Higher Education in the Global Context

ERIC Educational Resources Information Center

Efimova, I. N.

2014-01-01

Global rankings constitute a powerful instrument for the positioning of universities in the world educational space. Institutions that are included on the list of the top five hundred get financial support from the state and from business structures; they attract the best instructors and professors from all over the world. In recognition of this,…

Army AL&T, October-December 2008

DTIC Science & Technology

2008-12-01

during the WIN-T technology demonstration Nov. 8, 2007, at Naval Air Engineering Station , Lakehurst, NJ. (U.S. Army photo by Russ Messeroll.) 16 OCTOBER...worldwide communications architecture, enabling connectivity from the global backbone to regional networks to posts/camps/ stations , and, lastly, to...Force Tracker. • Tacticomp™ wireless and Global Positioning System(GPS)-enabled hand-held computer. • One Station Remote Video Terminal. • Counter

Measuring precise sea level from a buoy using the global positioning system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rocken, C.; Kelecy, T.M.; Born, G.H.

1990-11-01

High-accuracy sea surface positioning is required for sea floor geodesy, satellite altimeter verification, and the study of sea level. An experiment to study the feasibility of using the Global Positioning System (GPS) for accurate sea surface positioning was conducted. A GPS-equipped buoy (floater) was deployed off the Scripps pier at La Jolla, California during December 13-15, 1989. Two reference GPS receivers were placed on land, one within {approximately}100 m of the floater, and the other about 80 km inland at the laser ranging site on Monument Peak. The position of the floater was determined relative to the land-fixed receivers using:more » (a) kinematic GPS processing software developed at the National Geodetic Survey (NGS), and (b) the Jet Propulsion Laboratory's GIPSY (GPS Inferred Positioning SYstem) software. Sea level and ocean wave spectra were calculated from GPPS measurements. These results were compared to measurements made with a NOAA tide gauge and a Paros{trademark} pressure transducer (PPT). GPS sea level for the short 100-m baseline agrees with the PPT sea level at the 1-cm level and has an rms variation of 5 mm over a period of 4 hours. Agreement between results with the two independent GPS analyses is on the order of a few millimeters. Processing of the longer Monument Peak - floater baseline is in progress and will require orbit adjustments and tropospheric modeling to obtain results comparable to the short baseline.« less

Time and frequency applications.

PubMed

Hellwig, H

1993-01-01

An overview is given of the capabilities of atomic clocks and quartz crystal oscillators in terms of available precision of time and frequency signals. The generation, comparison, and dissemination of time and frequency is then discussed. The principal focus is to survey uses of time and frequency in navigation, communication, and science. The examples given include the Global Positioning System, a satellite-based global navigation system, and general and dedicated communication networks, as well as experiments in general relativity and radioastronomy. The number of atomic clocks and crystal oscillators that are in actual use worldwide is estimated.

Global stability and tumor clearance conditions for a cancer chemotherapy system

NASA Astrophysics Data System (ADS)

Valle, Paul A.; Starkov, Konstantin E.; Coria, Luis N.

2016-11-01

In this paper we study the global dynamics of a cancer chemotherapy system presented by de Pillis et al. (2007). This mathematical model describes the interaction between tumor cells, effector-immune cells, circulating lymphocytes and chemotherapy treatment. By applying the localization method of compact invariant sets, we find lower and upper bounds for these three cells populations. Further, we define a bounded domain in R+,04 where all compact invariant sets of the system are located and provide conditions under which this domain is positively invariant. We apply LaSalle's invariance principle and one result concerning two-dimensional competitive systems in order to derive sufficient conditions for tumor clearance and global asymptotic stability of the tumor-free equilibrium point. These conditions are computed by using bounds of the localization domain and they are given in terms of the chemotherapy treatment. Finally, we perform numerical simulations in order to illustrate our results.

Friend or Foe? Urbanization and the Biosphere

NASA Astrophysics Data System (ADS)

Schneider, A.

2008-12-01

The environmental influence of urban areas is still often assumed to be negligible at global scales. Although local environmental conditions such as the urban heat island effect are well-documented, surprisingly little work has focused on cross-scale interactions, or the ways in which local urban processes cumulatively impact global changes. Given the rapid rates of rural-urban migration, economic development and urban spatial expansion, improved systems for measuring, monitoring and modeling the global environmental impacts of cities should receive far greater scientific attention. This presentation will summarize urban environmental issues and impacts at local, regional and global scales and introduce the fundamental concepts and tools needed to measure and respond to these problems. Newly available datasets for the distribution and intensity of urban land use will be introduced, demonstrating the importance of clearly defining 'urbanized' land for empirical studies at the global scale. The negative environmental impacts of urban development will be compared with the often over-looked "positives" of urban growth from a global environmental perspective. Progress in understanding and forecasting the global impacts of urban areas will require systematic global urban research designs that treat cities as urban systems, anthropogenic biomes and urban ecoregions. The challenges and opportunities of global environmental research on urban areas have important implications not only for current research but also for educating the next generation of earth system scientists.

Geometrically constrained kinematic global navigation satellite systems positioning: Implementation and performance

NASA Astrophysics Data System (ADS)

Asgari, Jamal; Mohammadloo, Tannaz H.; Amiri-Simkooei, Ali Reza

2015-09-01

GNSS kinematic techniques are capable of providing precise coordinates in extremely short observation time-span. These methods usually determine the coordinates of an unknown station with respect to a reference one. To enhance the precision, accuracy, reliability and integrity of the estimated unknown parameters, GNSS kinematic equations are to be augmented by possible constraints. Such constraints could be derived from the geometric relation of the receiver positions in motion. This contribution presents the formulation of the constrained kinematic global navigation satellite systems positioning. Constraints effectively restrict the definition domain of the unknown parameters from the three-dimensional space to a subspace defined by the equation of motion. To test the concept of the constrained kinematic positioning method, the equation of a circle is employed as a constraint. A device capable of moving on a circle was made and the observations from 11 positions on the circle were analyzed. Relative positioning was conducted by considering the center of the circle as the reference station. The equation of the receiver's motion was rewritten in the ECEF coordinates system. A special attention is drawn onto how a constraint is applied to kinematic positioning. Implementing the constraint in the positioning process provides much more precise results compared to the unconstrained case. This has been verified based on the results obtained from the covariance matrix of the estimated parameters and the empirical results using kinematic positioning samples as well. The theoretical standard deviations of the horizontal components are reduced by a factor ranging from 1.24 to 2.64. The improvement on the empirical standard deviation of the horizontal components ranges from 1.08 to 2.2.

47 CFR 80.409 - Station logs.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., the Officer of the Navigational Watch, or GMDSS Operator on watch, shall update the embedded position... (vessels subject to the Global Maritime Distress and Safety System (GMDSS) should also refer to subpart W...

47 CFR 80.409 - Station logs.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., the Officer of the Navigational Watch, or GMDSS Operator on watch, shall update the embedded position... (vessels subject to the Global Maritime Distress and Safety System (GMDSS) should also refer to subpart W...

Onboard utilization of ground control points for image correction. Volume 3: Ground control point simulation software design

NASA Technical Reports Server (NTRS)

1981-01-01

The software developed to simulate the ground control point navigation system is described. The Ground Control Point Simulation Program (GCPSIM) is designed as an analysis tool to predict the performance of the navigation system. The system consists of two star trackers, a global positioning system receiver, a gyro package, and a landmark tracker.

Bacterial differentiation via gradual activation of global regulators.

PubMed

Kovács, Ákos T

2016-02-01

Bacteria have evolved to adapt to various conditions and respond to certain stress conditions. The ability to sense and efficiently reply to these environmental effects involve versatile array of sensors and global or specific regulators. Interestingly, modulation of the levels of active global regulators enables bacteria to respond to diverse signals via a single central transcriptional regulator and to activate or repress certain differentiation pathways at a spatio-temporal manner. The Gram-positive Bacillus subtilis is an ideal bacterium to study how membrane bound and cytoplasmic sensor kinases affect the level of phosphorylated global regulator, Spo0A which in response activates genes related to sliding, biofilm formation, and sporulation. In addition, other global regulators, including the two-component system DegS-DegU, modulate overlapping and complementary genes in B. subtilis related to surface colonization and biofilm formation. The intertwinement of global regulatory systems also allows the accurate modulation of differentiation pathways. Studies in the last decade enable us to get a deeper insight into the role of global regulators on the smooth transition of developmental processes in B. subtilis.

Autonomous Relative Navigation for Formation-Flying Satellites Using GPS

NASA Technical Reports Server (NTRS)

Gramling, Cheryl; Carpenter, J. Russell; Long, Anne; Kelbel, David; Lee, Taesul

2000-01-01

The Goddard Space Flight Center is currently developing advanced spacecraft systems to provide autonomous navigation and control of formation flyers. This paper discusses autonomous relative navigation performance for a formation of four eccentric, medium-altitude Earth-orbiting satellites using Global Positioning System (GPS) Standard Positioning Service (SPS) and "GPS-like " intersatellite measurements. The performance of several candidate relative navigation approaches is evaluated. These analyses indicate that an autonomous relative navigation position accuracy of 1meter root-mean-square can be achieved by differencing high-accuracy filtered solutions if only measurements from common GPS space vehicles are used in the independently estimated solutions.

The GPS Topex/Poseidon precise orbit determination experiment - Implications for design of GPS global networks

NASA Technical Reports Server (NTRS)

Lindqwister, Ulf J.; Lichten, Stephen M.; Davis, Edgar S.; Theiss, Harold L.

1993-01-01

Topex/Poseidon, a cooperative satellite mission between United States and France, aims to determine global ocean circulation patterns and to study their influence on world climate through precise measurements of sea surface height above the geoid with an on-board altimeter. To achieve the mission science aims, a goal of 13-cm orbit altitude accuracy was set. Topex/Poseidon includes a Global Positioning System (GPS) precise orbit determination (POD) system that has now demonstrated altitude accuracy better than 5 cm. The GPS POD system includes an on-board GPS receiver and a 6-station GPS global tracking network. This paper reviews early GPS results and discusses multi-mission capabilities available from a future enhanced global GPS network, which would provide ground-based geodetic and atmospheric calibrations needed for NASA deep space missions while also supplying tracking data for future low Earth orbiters. Benefits of the enhanced global GPS network include lower operations costs for deep space tracking and many scientific and societal benefits from the low Earth orbiter missions, including improved understanding of ocean circulation, ocean-weather interactions, the El Nino effect, the Earth thermal balance, and weather forecasting.

A Type of Non-cable Self-Posioning Seismograph Served For SinoProbe Project In China

NASA Astrophysics Data System (ADS)

Yang, H.; Lin, J.; Chen, Z.; Zhang, L.; Huaizhu, Z.; Zheng, F.; Seismic Instrument Design Team

2011-12-01

A type of cableless self-positioning telemetry seismograph designed for deep exploration is introduced in this article. The seismograph adopts 24-bit ADC and the analog circuits are designed carefully to attain a low noise level of 300nV RMS. It also uses 24-bit DAC and FPGA circuits to perform self-test including noise level, trace crosstalk, CMRR, harmonic distortion, geophone resitor testing, pulse testing, gain calibration and etc. As the testing result shows, the analog acquisition performances are similar to the most popular seismograph 428XL system from Sercel. However, the seismograph has a different structure with 428XL. It gets rid of cables and stores seismic data in mass non-volatile memory, and meanwhile it employs GPS combined with Compass global navigation satellite system to implement synchronous data aquisiton and self-positioning. In addition, the seismograph has a built-in WiFi module and can communicate with a cental server in Ad-hoc mode or AP mode depending on the distance between the seismograph and the central server. The working status and seismic data quality can be monitored through the WiFi network and some seismic data can be transmitted back on demand. When the distance between adjacent seismographs exceed 500 metres, the Compass global navigation satellite system which supports global communication can be used to send necessary data. At last, dynamic power management is emplyed and the system working voltage and frequency will be changed as the system runs into different status, and also all circuit modules can be switched off when not needed. Because of all the benefits listed above, the seismograph can be used in a variety of ways as needed, such as seismic network, deep seismic reflection exploration, wide-angle seismic reflection and refraction exploration, ore zone seismic exploration and etc. To sum up, the cable-less self-positioning seismograph employs mass non-volatile storage technology, global navigation satellite sytem, WiFi modules and dynamic power management technology to attain a flexible data acquisition system suitable for most of the seismic deep exploration in SinoProbe launched in China.

INTEGRATED INS/GPS NAVIGATION FROM A POPULAR PERSPECTIVE

DOT National Transportation Integrated Search

2002-02-13

Inertial navigation, blended with other navigation aids Global Positioning System (GPS) in particular, has gained significance due to enhanced navigation and inertial reference performance and dissimilarity for fault tolerance and anti-jamming. Relat...

GPS Civil Monitoring Performance Specification

DOT National Transportation Integrated Search

2009-02-10

This Civil Monitoring Performance Specification (CMPS) is published and maintained at : the direction of the Program Manager for Civil Applications, Global Positioning Systems : Wing (GPSW). The purpose of this document is to provide a comprehensive ...

Field Characterization | Concentrating Solar Power | NREL

Science.gov Websites

receivers for performance issues. It uses an infrared (IR) camera, global positioning system (GPS each row of a parabolic trough plant, using the GPS data to automate IR imaging and analyze

77 FR 771 - Proposed Establishment of Class E Airspace; Marion, AL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-06

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at Vaiden Field. This action... airspace at Marion, AL, providing the controlled airspace required to support the new RNAV GPS standard...

75 FR 76650 - Proposed Modification of Class E Airspace; Bryce Canyon, UT

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-09

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at Bryce Canyon Airport. The FAA.... Controlled airspace is necessary to accommodate aircraft using the RNAV (GPS) Standard Instrument Approach...

High-precision GPS vehicle tracking to improve safety.

DOT National Transportation Integrated Search

2016-09-01

Commercial Global Positioning System (GPS) devices are being used in transportation for applications : including vehicle navigation, traffic monitoring, and tracking commercial and public transit vehicles. The : current state-of-practice technology i...

DOTD standards for GPS data collection accuracy : research project capsule.

DOT National Transportation Integrated Search

2013-12-01

Global Navigational Satellite Systems (GNSS), which includes GPS technologies : maintained by the United States, are used extensively throughout government : and industry. These technologies continue to revolutionize positional data : collection acti...

Measurement of ridge-spreading movements (Sackungen) at Bald Eagle Mountain, Lake County, Colorado, II : continuation of the 1975-1989 measurements using a Global Positioning System in 1997 and 1999

USGS Publications Warehouse

Varnes, David J.; Coe, J.A.; Godt, J.W.; Savage, W.Z.; Savage, J.E.

2000-01-01

Measurements of ridge-spreading movements at Bald Eagle Mountain in north-central Colorado were reported in USGS Open-File Report 90-543 for the years 1975-1989. Measurements were renewed in 1997 and 1999 using the Global Positioning System (GPS). Movements are generally away from a ridge-top graben and appear to be concentrated along 3 or 4 trenches with uphill facing scarps that are parallel with slope contours. A point just below the lowest trench has moved the most? a total of 8.3 cm horizontally and slightly downward from 1977 to 1999 relative to an assumed stable point on the periphery of the graben. Movements from 1997 to 1999 are less than 1 cm or within the error of measurement.

Global Radius of Curvature Estimation and Control System for Segmented Mirrors

NASA Technical Reports Server (NTRS)

Rakoczy, John M. (Inventor)

2006-01-01

An apparatus controls positions of plural mirror segments in a segmented mirror with an edge sensor system and a controller. Current mirror segment edge sensor measurements and edge sensor reference measurements are compared with calculated edge sensor bias measurements representing a global radius of curvature. Accumulated prior actuator commands output from an edge sensor control unit are combined with an estimator matrix to form the edge sensor bias measurements. An optimal control matrix unit then accumulates the plurality of edge sensor error signals calculated by the summation unit and outputs the corresponding plurality of actuator commands. The plural mirror actuators respond to the actuator commands by moving respective positions of the mixor segments. A predetermined number of boundary conditions, corresponding to a plurality of hexagonal mirror locations, are removed to afford mathematical matrix calculation.

Constraints on Pacific plate kinematics and dynamics with global positioning system measurements

NASA Technical Reports Server (NTRS)

Dixon, T. H.; Golombek, M. P.; Thornton, C. L.

1985-01-01

A measurement program designed to investigate kinematic and dynamic aspects of plate tectonics in the Pacific region by means of satellite observations is proposed. Accuracy studies are summarized showing that for short baselines (less than 100 km), the measuring accuracy of global positioning system (GPS) receivers can be in the centimeter range. For longer baselines, uncertainty in the orbital ephemerides of the GPS satellites could be a major source of error. Simultaneous observations at widely (about 300 km) separated fiducial stations over the Pacific region, should permit an accuracy in the centimeter range for baselines of up to several thousand kilometers. The optimum performance level is based on the assumption of that fiducial baselines are known a priori to the centimeter range. An example fiducial network for a GPS study of the South Pacific region is described.

Coastal bathymetry data collected in June 2014 from Fire Island, New York—The wilderness breach and shoreface

USGS Publications Warehouse

Nelson, Timothy R.; Miselis, Jennifer L.; Hapke, Cheryl J.; Wilson, Kathleen E.; Henderson, Rachel E.; Brenner, Owen T.; Reynolds, Billy J.; Hansen, Mark E.

2016-08-02

Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, collected bathymetric data along the upper shoreface and within the wilderness breach at Fire Island, New York, in June 2014. The U.S. Geological Survey is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the shoreface along Fire Island and model the evolution of the wilderness breach as a part of the Hurricane Sandy Supplemental Project GS2-2B. During this study, bathymetry was collected with single-beam echo sounders and global positioning systems, mounted to personal watercraft, along the Fire Island shoreface and within the wilderness breach. Additional bathymetry was collected using backpack global positioning systems along the flood shoals and shallow channels within the wilderness breach.

Physical activity measured using global positioning system tracking in non-small cell lung cancer: an observational study.

PubMed

Granger, Catherine L; Denehy, Linda; McDonald, Christine F; Irving, Louis; Clark, Ross A

2014-11-01

Increasingly physical activity (PA) is being recognized as an important outcome in non-small cell lung cancer (NSCLC). We investigated PA using novel global positioning system (GPS) tracking individuals with NSCLC and a group of similar-aged healthy individuals. A prospective cross-sectional multicenter study. Fifty individuals with NSCLC from 3 Australian tertiary hospitals and 35 similar-aged healthy individuals without cancer were included. Individuals with NSCLC were assessed pretreatment. Primary measures were triaxial accelerometery (steps/day) and GPS tracking (outdoor PA behavior). Secondary measures were questionnaires assessing depression, motivation to exercise, and environmental barriers to PA. Between-group comparisons were analyzed using analysis of covariance. Individuals with NSCLC engaged in significantly less PA than similar-aged healthy individuals (mean difference 2363 steps/day, P = .007) and had higher levels of depression (P = .027) and lower motivation to exercise (P = .001). Daily outdoor walking time (P = .874) and distance travelled away from home (P = .883) were not different between groups. Individuals with NSCLC spent less time outdoors in their local neighborhood area (P < .001). A greater number of steps per day was seen in patients who were less depressed (r = .39) or had better access to nonresidential destinations such as shopping centers (r = .25). Global positioning system tracking appears to be a feasible methodology for adult cancer patients and holds promise for use in future studies investigating PA and or lifestyle behaviors. © The Author(s) 2014.

Seven Defense Priorities for the New Administration

DTIC Science & Technology

2016-12-01

building consume human and financial military resources for decades. New weapons like cyber and autonomous systems are aimed at the heart of the U.S...information infrastructure enables for adversaries and for the U.S.; 5. Anticipating intelligent systems and autonomy including numbers and...challenging in a complex electromagnetic environment ...............................................37 Space and the global positioning system play a

LiDAR and Image Point Cloud Comparison

DTIC Science & Technology

2014-09-01

UAV unmanned aerial vehicle USGS United States Geological Survey UTM Universal Transverse Mercator WGS 84 World Geodetic System 1984 WSI...19  1.  Physics of LiDAR Systems ................................................................20  III.  DATA AND SOFTWARE...ground control point GPS Global Positioning System IMU inertial measurements unit LiDAR light detection and ranging MI mutual information MVS

A simultaneously calibration approach for installation and attitude errors of an INS/GPS/LDS target tracker.

PubMed

Cheng, Jianhua; Chen, Daidai; Sun, Xiangyu; Wang, Tongda

2015-02-04

To obtain the absolute position of a target is one of the basic topics for non-cooperated target tracking problems. In this paper, we present a simultaneously calibration method for an Inertial navigation system (INS)/Global position system (GPS)/Laser distance scanner (LDS) integrated system based target positioning approach. The INS/GPS integrated system provides the attitude and position of observer, and LDS offers the distance between the observer and the target. The two most significant errors are taken into jointly consideration and analyzed: (1) the attitude measure error of INS/GPS; (2) the installation error between INS/GPS and LDS subsystems. Consequently, a INS/GPS/LDS based target positioning approach considering these two errors is proposed. In order to improve the performance of this approach, a novel calibration method is designed to simultaneously estimate and compensate these two main errors. Finally, simulations are conducted to access the performance of the proposed target positioning approach and the designed simultaneously calibration method.

Positioning stability improvement with inter-system biases on multi-GNSS PPP

NASA Astrophysics Data System (ADS)

Choi, Byung-Kyu; Yoon, Hasu

2018-07-01

The availability of multiple signals from different Global Navigation Satellite System (GNSS) constellations provides opportunities for improving positioning accuracy and initial convergence time. With dual-frequency observations from the four constellations (GPS, GLONASS, Galileo, and BeiDou), it is possible to investigate combined GNSS precise point positioning (PPP) accuracy and stability. The differences between GNSS systems result in inter-system biases (ISBs). We consider several ISB values such as GPS-GLONASS, GPS-Galileo, and GPS-BeiDou. These biases are compliant with key parameters defined in the multi-GNSS PPP processing. In this study, we present a unified PPP method that sets ISB values as fixed or constant. A comprehensive analysis that includes satellite visibility, position dilution of precision, position accuracy is performed to evaluate a unified PPP method with constrained cut-off elevation angles. Compared to the conventional PPP solutions, our approach shows more stable positioning at a constrained cut-off elevation angle of 50 degrees.

Mapping the Future Today: The Community College of Baltimore County Geospatial Applications Program

ERIC Educational Resources Information Center

Jeffrey, Scott; Alvarez, Jaime

2010-01-01

The Geospatial Applications Program at the Community College of Baltimore County (CCBC), located five miles west of downtown Baltimore, Maryland, provides comprehensive instruction in geographic information systems (GIS), remote sensing and global positioning systems (GPS). Geospatial techniques, which include computer-based mapping and remote…

77 FR 39652 - Proposed Establishment of Class E Airspace; La Belle, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-05

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at La Belle Municipal Airport. This action would enhance the safety and airspace management of Instrument Flight Rules (IFR...; Airspace Docket No. 12-ASO-29) and be submitted in triplicate to the Docket Management System (see...

76 FR 49390 - Proposed Establishment of Class E Airspace; Palmyra, PA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-10

...) Global Positioning System (GPS) Standard Instrument Approach Procedures at Reigle Field. This action would enhance the safety and airspace management of Instrument Flight Rules (IFR) operations at the...; Airspace Docket No. 11-ASO-17) and be submitted in triplicate to the Docket Management System (see...

78 FR 52111 - Proposed Establishment of Class E Airspace; Aliceville, AL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-22

... (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedure (SIAP) serving George Downer Airport. This action would enhance the safety and airspace management of Instrument Flight Rules...; Airspace Docket No. 13-ASO-7) and be submitted in triplicate to the Docket Management System (see ADDRESSES...

78 FR 18269 - Proposed Modification of Class E Airspace; Clifton/Morenci, AZ

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... accommodate aircraft using Area Navigation (RNAV) Global Positioning System (GPS) standard instrument approach procedures at Greenlee County Airport. The FAA is proposing this action to enhance the safety and management... be submitted in triplicate to the Docket Management System (see ADDRESSES section for address and...

76 FR 35362 - Proposed Amendment of Class E Airspace; Shelby, MT

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-17

... using Area Navigation (RNAV) Global Positioning System (GPS) standard instrument approach procedures at Shelby Airport. The FAA is proposing this action to enhance the safety and management of aircraft... submitted in triplicate to the Docket Management System (see ADDRESSES section for address and phone number...

Mapping where We Live and Play with GPS Technology

ERIC Educational Resources Information Center

Gentry, Deborah J.

2006-01-01

As a result of technological advances such as the Global Positioning System (GPS) and the Geographic Information System (GIS), mapping practices and applications have become far more sophisticated. This article suggests family and consumer sciences students and professionals consider using GPS technology to map their communities as a strategy to…

75 FR 59934 - Amendment to Class E Airspace; Smithfield, NC

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-29

... Class E airspace at Johnston County Airport, Smithfield, NC, by correcting an omission of the geographic coordinates of the Area Navigation (RNAV) Global Positioning System (GPS) Special Standard Instrument Approach... System. DATES: Effective 0901 UTC, January 13, 2011. The Director of the Federal Register approves this...

76 FR 79564 - Proposed Establishment of Class E Airspace; Bellefonte, PA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-22

... action proposes to establish Class E Airspace at Bellefonte, PA, to accommodate the Area Navigation (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedures at Bellefonte Airport. This...; Airspace Docket No. 11-AEA-23) and be submitted in triplicate to the Docket Management System (see...

An Integrated Field-Based Approach to Building Teachers' Geoscience Skills

ERIC Educational Resources Information Center

Almquist, Heather; Stanley, George; Blank, Lisa; Hendrix, Marc; Rosenblatt, Megan; Hanfling, Seymour; Crews, Jeffrey

2011-01-01

The Paleo Exploration Project was a professional development program for K-12 teachers from rural eastern Montana. The curriculum was designed to incorporate geospatial technologies, including Global Positioning Systems (GPS), Geographic Information Systems (GIS), and total station laser surveying, with authentic field experiences in geology and…

Professional Development: Teachers Use of GIS to Enhance Student Learning

ERIC Educational Resources Information Center

McClurg, Patricia A.; Buss, Alan

2007-01-01

This article explains a professional development experience of fifth to twelfth grade teachers in using geographic information systems (GIS) and global positioning systems (GPS) technologies to enhance classroom teaching and learning environments. A key challenge faced by the developers was whether teachers would value the technology tools enough…

78 FR 67132 - GPS Satellite Simulator Control Working Group Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-08

... DEPARTMENT OF DEFENSE Department of the Air Force GPS Satellite Simulator Control Working Group Meeting AGENCY: Space and Missile Systems Center, Global Positioning Systems (GPS) Directorate, Air Force... Control Working Group (SSCWG) meeting on 6 December 2013 from 0900-1300 PST at Los Angeles Air Force Base...

77 FR 70421 - GPS Satellite Simulator Control Working Group Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... DEPARTMENT OF DEFENSE Department of the Air Force GPS Satellite Simulator Control Working Group Meeting AGENCY: Space and Missile Systems Center, Global Positioning Systems (GPS) Directorate, Department... Control Working Group (SSCWG) meeting on 14 December 2012 from 0900-1600 PST at Los Angeles Air Force Base...

Geospatial Technologies: Real Projects in Real Classrooms

ERIC Educational Resources Information Center

Kolvoord, Bob

2008-01-01

Geospatial technologies of geographic information systems, global positioning systems, and remote sensing are just a few of the projects that evoke an unexpected drive and devotion from high school students in Virginia. Their integration into different curricular areas lets students focus on understanding their community and the many issues that…

Multi-modal cockpit interface for improved airport surface operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J. (Inventor); Bailey, Randall E. (Inventor); Prinzel, III, Lawrence J. (Inventor); Kramer, Lynda J. (Inventor); Williams, Steven P. (Inventor)

2010-01-01

A system for multi-modal cockpit interface during surface operation of an aircraft comprises a head tracking device, a processing element, and a full-color head worn display. The processing element is configured to receive head position information from the head tracking device, to receive current location information of the aircraft, and to render a virtual airport scene corresponding to the head position information and the current aircraft location. The full-color head worn display is configured to receive the virtual airport scene from the processing element and to display the virtual airport scene. The current location information may be received from one of a global positioning system or an inertial navigation system.

Characterization of a multi-user indoor positioning system based on low cost depth vision (Kinect) for monitoring human activity in a smart home.

PubMed

Sevrin, Loïc; Noury, Norbert; Abouchi, Nacer; Jumel, Fabrice; Massot, Bertrand; Saraydaryan, Jacques

2015-01-01

An increasing number of systems use indoor positioning for many scenarios such as asset tracking, health care, games, manufacturing, logistics, shopping, and security. Many technologies are available and the use of depth cameras is becoming more and more attractive as this kind of device becomes affordable and easy to handle. This paper contributes to the effort of creating an indoor positioning system based on low cost depth cameras (Kinect). A method is proposed to optimize the calibration of the depth cameras, to describe the multi-camera data fusion and to specify a global positioning projection to maintain the compatibility with outdoor positioning systems. The monitoring of the people trajectories at home is intended for the early detection of a shift in daily activities which highlights disabilities and loss of autonomy. This system is meant to improve homecare health management at home for a better end of life at a sustainable cost for the community.

Ionospheric Slant Total Electron Content Analysis Using Global Positioning System Based Estimation

NASA Technical Reports Server (NTRS)

Komjathy, Attila (Inventor); Mannucci, Anthony J. (Inventor); Sparks, Lawrence C. (Inventor)

2017-01-01

A method, system, apparatus, and computer program product provide the ability to analyze ionospheric slant total electron content (TEC) using global navigation satellite systems (GNSS)-based estimation. Slant TEC is estimated for a given set of raypath geometries by fitting historical GNSS data to a specified delay model. The accuracy of the specified delay model is estimated by computing delay estimate residuals and plotting a behavior of the delay estimate residuals. An ionospheric threat model is computed based on the specified delay model. Ionospheric grid delays (IGDs) and grid ionospheric vertical errors (GIVEs) are computed based on the ionospheric threat model.

Global calibration of multi-cameras with non-overlapping fields of view based on photogrammetry and reconfigurable target

NASA Astrophysics Data System (ADS)

Xia, Renbo; Hu, Maobang; Zhao, Jibin; Chen, Songlin; Chen, Yueling

2018-06-01

Multi-camera vision systems are often needed to achieve large-scale and high-precision measurement because these systems have larger fields of view (FOV) than a single camera. Multiple cameras may have no or narrow overlapping FOVs in many applications, which pose a huge challenge to global calibration. This paper presents a global calibration method for multi-cameras without overlapping FOVs based on photogrammetry technology and a reconfigurable target. Firstly, two planar targets are fixed together and made into a long target according to the distance between the two cameras to be calibrated. The relative positions of the two planar targets can be obtained by photogrammetric methods and used as invariant constraints in global calibration. Then, the reprojection errors of target feature points in the two cameras’ coordinate systems are calculated at the same time and optimized by the Levenberg–Marquardt algorithm to find the optimal solution of the transformation matrix between the two cameras. Finally, all the camera coordinate systems are converted to the reference coordinate system in order to achieve global calibration. Experiments show that the proposed method has the advantages of high accuracy (the RMS error is 0.04 mm) and low cost and is especially suitable for on-site calibration.

Use of global positioning system measurements to determine geocentric coordinates and variations in Earth orientation

NASA Technical Reports Server (NTRS)

Malla, R. P.; Wu, S.-C.; Lichten, S. M.

1993-01-01

Geocentric tracking station coordinates and short-period Earth-orientation variations can be measured with Global Positioning System (GPS) measurements. Unless calibrated, geocentric coordinate errors and changes in Earth orientation can lead to significant deep-space tracking errors. Ground-based GPS estimates of daily and subdaily changes in Earth orientation presently show centimeter-level precision. Comparison between GPS-estimated Earth-rotation variations, which are the differences between Universal Time 1 and Universal Coordinated Time (UT1-UTC), and those calculated from ocean tide models suggests that observed subdaily variations in Earth rotation are dominated by oceanic tidal effects. Preliminary GPS estimates for the geocenter location (from a 3-week experiment) agree with independent satellite laser-ranging estimates to better than 10 cm. Covariance analysis predicts that temporal resolution of GPS estimates for Earth orientation and geocenter improves significantly when data collected from low Earth-orbiting satellites as well as from ground sites are combined. The low Earth GPS tracking data enhance the accuracy and resolution for measuring high-frequency global geodynamical signals over time scales of less than 1 day.

New results on global exponential dissipativity analysis of memristive inertial neural networks with distributed time-varying delays.

PubMed

Zhang, Guodong; Zeng, Zhigang; Hu, Junhao

2018-01-01

This paper is concerned with the global exponential dissipativity of memristive inertial neural networks with discrete and distributed time-varying delays. By constructing appropriate Lyapunov-Krasovskii functionals, some new sufficient conditions ensuring global exponential dissipativity of memristive inertial neural networks are derived. Moreover, the globally exponential attractive sets and positive invariant sets are also presented here. In addition, the new proposed results here complement and extend the earlier publications on conventional or memristive neural network dynamical systems. Finally, numerical simulations are given to illustrate the effectiveness of obtained results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Global Ionospheric Perturbations Monitored by the Worldwide GPS Network

NASA Technical Reports Server (NTRS)

Ho, C. M.; Mannucci, A. T.; Lindqwister, U. J.; Pi, X. Q.

1996-01-01

Based on the delays of these (Global Positioning System-GPS)signals, we have generated high resolution global ionospheric TEC (Total Electronic Changes) maps at 15-minute intervals. Using a differential method comparing storm time maps with quiet time maps, we find that the ionopshere during this time storm has increased significantly (the percentage change relative to quiet times is greater than 150 percent) ...These preliminary results (those mentioned above plus other in the paper)indicate that the differential maping method, which is based on GPS network measurements appears to be a useful tool for studying the global pattern and evolution process of the entire ionospheric perturbation.

Stability and bifurcation analysis on a ratio-dependent predator-prey model with time delay

NASA Astrophysics Data System (ADS)

Xu, Rui; Gan, Qintao; Ma, Zhien

2009-08-01

A ratio-dependent predator-prey model with time delay due to the gestation of the predator is investigated. By analyzing the corresponding characteristic equations, the local stability of a positive equilibrium and a semi-trivial boundary equilibrium is discussed, respectively. Further, it is proved that the system undergoes a Hopf bifurcation at the positive equilibrium. Using the normal form theory and the center manifold reduction, explicit formulae are derived to determine the direction of bifurcations and the stability and other properties of bifurcating periodic solutions. By means of an iteration technique, sufficient conditions are obtained for the global attractiveness of the positive equilibrium. By comparison arguments, the global stability of the semi-trivial equilibrium is also addressed. Numerical simulations are carried out to illustrate the main results.

Analysis of California Condor (Gymnogyps californianus) use of six management units using location data from global positioning system transmitters, southern California, 2004-09-Initial report

USGS Publications Warehouse

Johnson, Matthew; Kern, Jeffrey; Haig, Susan M.

2010-01-01

This report provides an analysis of California Condor (Gymnogyps californianus) space use of six management units in southern California (Hopper Mountain and Bitter Creek National Wildlife Refuges, Wildlands Conservancy-Wind Wolves Preserve, Tejon Mountain Village Specific Plan, California Condor Study Area, and the Tejon Ranch excluding Tejon Mountain Village Specific Plan and California Condor Study Area). Space use was analyzed to address urgent management needs using location data from Global Positioning System transmitters. The U.S. Fish and Wildlife Service provided the U.S. Geological Survey with location data (2004-09) for California Condors from Global Positioning System transmitters and Geographic Information System data for the six management units in southern California. We calculated relative concentration of use estimates for each management unit for each California Condor (n = 21) on an annual basis (n = 39 annual home ranges) and evaluated resource selection for the population each year using the individual as our sampling unit. The most striking result from our analysis was the recolonization of the Tejon Mountain Village Specific Plan, California Condor Study Area, and Tejon Ranch management units during 2008. During 2004-07, the home range estimate for two (25 percent) California Condors overlapped the Tejon Mountain Village Specific Plan, California Condor Study Area, and Tejon Ranch management units (n = 8), and use within the annual home range generally was bimodal and was concentrated on the Bitter Creek and Hopper Mountain National Wildlife Refuges. However, 10 (77 percent) California Condor home ranges overlapped the Tejon Mountain Village Specific Plan, California Condor Study Area, and Tejon Ranch management units during 2008 (n = 13), and by 2009, the home range of every condor carrying a Global Positioning System transmitter (n = 14) overlapped these management units. Space use was multimodal within the home range during 2008-09 and was concentrated on Hopper Mountain Refuge in the south, Bittercreek Refuge and the Wind Wolves Preserve in the northwest, and the Tejon Mountain Village Specific Plan, California Condor Study Area, and Tejon Ranch management units in the northeast. Recolonization of the Tejon Mountain Village Specific Plan, California Condor Study Area, and Tejon Ranch management units reestablished traditional condor movement and foraging patterns in southern California and provides the travel corridor (approximately 20 kilometers wide) for recolonization of the northeastern part of the species historical range.

Incorporation of Differential Global Positioning System Measurements Using an Extended Kalman Filter for Improved Reference System Performance

DTIC Science & Technology

1991-12-01

Kalman filtering. As GPS usage expands throughout the military and civilian communities, I hope this thesis provides a small contribution in this area...of the measurement’equation. In this thesis, some of the INS states not part of a measurement equation need a small amount of added noise to...estimating the state, but the variance often goes negative. A small amount of added noise in the filter keeps the variance of the state positive and does not

Impact of NAVSTAR Global Positioning System on Military Plans for Navigation and Position Fixing Systems

DTIC Science & Technology

1975-10-01

There are however significant factors evident in the study , but not amenable to fiscal quantifi- cation that provide impetus for employment of GPS...assumed in this study . (For summary of these factors , see Section A.2.a, page 25, in the. Discussion.) C These ranges of GPS cost, as well as the...this study . However, they may be a major factor in the teasibility of eliminating the single Doppler, which would be a significant added cost avoidance

Global fast dynamic terminal sliding mode control for a quadrotor UAV.

PubMed

Xiong, Jing-Jing; Zhang, Guo-Bao

2017-01-01

A control method based on global fast dynamic terminal sliding mode control (TSMC) technique is proposed to design the flight controller for performing the finite-time position and attitude tracking control of a small quadrotor UAV. Firstly, the dynamic model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. Secondly, the dynamic flight controllers of the quadrotor are formulated based on global fast dynamic TSMC, which is able to guarantee that the position and velocity tracking errors of all system state variables converge to zero in finite-time. Moreover, the global fast dynamic TSMC is also able to eliminate the chattering phenomenon caused by the switching control action and realize the high precision performance. In addition, the stabilities of two subsystems are demonstrated by Lyapunov theory, respectively. Lastly, the simulation results are given to illustrate the effectiveness and robustness of the proposed control method in the presence of external disturbances. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

System identification for precision control of a wingsailed GPS-guided catamaran

NASA Astrophysics Data System (ADS)

Elkaim, Gabriel Hugh

This thesis details the Atlantis project, whose aim is the design, development, and experimental testing of an autonomous wind-propelled marine craft. Functionally, such a vehicle is the marine equivalent of an unmanned aerial vehicle (UAV), and would serve similar purposes. The Atlantis project has been able to demonstrate an advance in control precision of a wind-propelled marine vehicle from typical commercial autopilot accuracy of 100 meters to an accuracy of better than one meter with a prototype based on a modified Prindle-19 light catamaran. The project involves substantial innovations in three areas: wind-propulsion system, overall system architecture, and sensors. The wind-propulsion system is a rigid wing-sail mounted vertically on bearings, mass balanced to allow free rotation in azimuth about a stub-mast. Aerodynamic torque about the stub-mast is trimmed using a flying tail mounted on booms aft of the wing. This arrangement allows the wing-sail to automatically attain the optimum angle to the wind, and weathervane into gusts without inducing large heeling moments. The sensor system uses differential Global Positioning System (DGPS) augmented by a low-cost attitude system based on accelerometer- and magnetometer-triads for position and velocity measurements. Accurate attitude determination is required to create a synthetic position sensor that is located at the center-of-gravity (c.g.) of the boat, rather than at the Global Positioning System (GPS) antenna location. A high-performance estimator/controller was implemented and tested on the full-scale prototype. The identified controllers were able to perform remarkably well, in the presence of wind and waves, tracking the desired line to within 0.3 meters (˜1 foot).

The GFZ real-time GNSS precise positioning service system and its adaption for COMPASS

NASA Astrophysics Data System (ADS)

Li, Xingxing; Ge, Maorong; Zhang, Hongping; Nischan, Thomas; Wickert, Jens

2013-03-01

Motivated by the IGS real-time Pilot Project, GFZ has been developing its own real-time precise positioning service for various applications. An operational system at GFZ is now broadcasting real-time orbits, clocks, global ionospheric model, uncalibrated phase delays and regional atmospheric corrections for standard PPP, PPP with ambiguity fixing, single-frequency PPP and regional augmented PPP. To avoid developing various algorithms for different applications, we proposed a uniform algorithm and implemented it into our real-time software. In the new processing scheme, we employed un-differenced raw observations with atmospheric delays as parameters, which are properly constrained by real-time derived global ionospheric model or regional atmospheric corrections and by the empirical characteristics of the atmospheric delay variation in time and space. The positioning performance in terms of convergence time and ambiguity fixing depends mainly on the quality of the received atmospheric information and the spatial and temporal constraints. The un-differenced raw observation model can not only integrate PPP and NRTK into a seamless positioning service, but also syncretize these two techniques into a unique model and algorithm. Furthermore, it is suitable for both dual-frequency and sing-frequency receivers. Based on the real-time data streams from IGS, EUREF and SAPOS reference networks, we can provide services of global precise point positioning (PPP) with 5-10 cm accuracy, PPP with ambiguity-fixing of 2-5 cm accuracy, PPP using single-frequency receiver with accuracy of better than 50 cm and PPP with regional augmentation for instantaneous ambiguity resolution of 1-3 cm accuracy. We adapted the system for current COMPASS to provide PPP service. COMPASS observations from a regional network of nine stations are used for precise orbit determination and clock estimation in simulated real-time mode, the orbit and clock products are applied for real-time precise point positioning. The simulated real-time PPP service confirms that real-time positioning services of accuracy at dm-level and even cm-level is achievable with COMPASS only.

Surface Hydrology in Global River Basins in the Off-Line Land-Surface GEOS Assimilation (OLGA) System

NASA Technical Reports Server (NTRS)

Bosilovich, Michael G.; Yang, Runhua; Houser, Paul R.

1998-01-01

Land surface hydrology for the Off-line Land-surface GEOS Analysis (OLGA) system and Goddard Earth Observing System (GEOS-1) Data Assimilation System (DAS) has been examined using a river routing model. The GEOS-1 DAS land-surface parameterization is very simple, using an energy balance prediction of surface temperature and prescribed soil water. OLGA uses near-surface atmospheric data from the GEOS-1 DAS to drive a more comprehensive parameterization of the land-surface physics. The two global systems are evaluated using a global river routing model. The river routing model uses climatologic surface runoff from each system to simulate the river discharge from global river basins, which can be compared to climatologic river discharge. Due to the soil hydrology, the OLGA system shows a general improvement in the simulation of river discharge compared to the GEOS-1 DAS. Snowmelt processes included in OLGA also have a positive effect on the annual cycle of river discharge and source runoff. Preliminary tests of a coupled land-atmosphere model indicate improvements to the hydrologic cycle compared to the uncoupled system. The river routing model has provided a useful tool in the evaluation of the GCM hydrologic cycle, and has helped quantify the influence of the more advanced land surface model.

School and Work: Does the Eastern Caribbean Education System Adequately Prepare Youth for the Global Economy? Skill Challenges in the Caribbean: Phase I Report. Report No. 38555

ERIC Educational Resources Information Center

World Bank Publications, 2007

2007-01-01

As the global economy rapidly changes and new technologies are introduced, more highly skilled workers are required. In the Organization of Eastern Caribbean States (OECS), firms struggle to fill skilled positions due to a lack of qualified candidates, while the number of unemployed low skilled workers is growing. This paradox especially affects…

Geoscience Australia Continuous Global Positioning System (CGPS) Station Field Campaign Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruddick, R.; Twilley, B.

2016-03-01

This station formed part of the Australian Regional GPS Network (ARGN) and South Pacific Regional GPS Network (SPRGN), which is a network of continuous GPS stations operating within Australia and its Territories (including Antarctica) and the Pacific. These networks support a number of different science applications including maintenance of the Geospatial Reference Frame, both national and international, continental and tectonic plate motions, sea level rise, and global warming.

Atmospheric and ocean sensing with GNSS

NASA Technical Reports Server (NTRS)

Yunck, Thomas P.; Hajj, George A.

2003-01-01

The 1980s and 1990s saw the Global Positioning System (GPS) transform space geodesy from an elite national enterprise to one open to the individual researcher. By adapting the tools from that endeavor we are learning to probe the atmosphere and the ocean surface in novel ways, including ground-based sensing of atmospheric moisture; space-based profiling of atmospheric refractivity by active limb sounding; and global ocean altimetry with reflected signals.

GNSS-Based Space Weather Systems Including COSMIC Ionospheric Measurements

NASA Technical Reports Server (NTRS)

Komjathy, Attila; Mandrake, Lukas; Wilson, Brian; Iijima, Byron; Pi, Xiaoqing; Hajj, George; Mannucci, Anthony J.

2006-01-01

The presentation outline includes University Corporation for Atmospheric Research (UCAR) and Jet Propulsion Laboratory (JPL) product comparisons, assimilating ground-based global positioning satellites (GPS) and COSMIC into JPL/University of Southern California (USC) Global Assimilative Ionospheric Model (GAIM), and JPL/USC GAIM validation. The discussion of comparisons examines Abel profiles and calibrated TEC. The JPL/USC GAIM validation uses Arecibo ISR, Jason-2 VTEC, and Abel profiles.

Global Trophic Position Comparison of Two Dominant Mesopelagic Fish Families (Myctophidae, Stomiidae) Using Amino Acid Nitrogen Isotopic Analyses

PubMed Central

Choy, C. Anela; Davison, Peter C.; Drazen, Jeffrey C.; Flynn, Adrian; Gier, Elizabeth J.; Hoffman, Joel C.; McClain-Counts, Jennifer P.; Miller, Todd W.; Popp, Brian N.; Ross, Steve W.; Sutton, Tracey T.

2012-01-01

The δ15N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer trophic connectivity. We undertook a novel cross-basin comparison of trophic position in two ecologically well-characterized and different groups of dominant mid-water fish consumers using amino acid nitrogen isotope compositions. We found that trophic positions estimated from the δ15N values of individual amino acids are nearly uniform within both families of these fishes across five global regions despite great variability in bulk tissue δ15N values. Regional differences in the δ15N values of phenylalanine confirmed that bulk tissue δ15N values reflect region-specific water mass biogeochemistry controlling δ15N values at the base of the food web. Trophic positions calculated from amino acid isotopic analyses (AA-TP) for lanternfishes (family Myctophidae) (AA-TP ∼2.9) largely align with expectations from stomach content studies (TP ∼3.2), while AA-TPs for dragonfishes (family Stomiidae) (AA-TP ∼3.2) were lower than TPs derived from stomach content studies (TP∼4.1). We demonstrate that amino acid nitrogen isotope analysis can overcome shortcomings of bulk tissue isotope analysis across biogeochemically distinct systems to provide globally comparative information regarding marine food web structure. PMID:23209656

Global trophic position comparison of two dominant mesopelagic fish families (Myctophidae, Stomiidae) using amino acid nitrogen isotopic analyses

USGS Publications Warehouse

Choy, C. Anela; Davison, Peter C.; Drazen, Jeffrey C.; Flynn, Adrian; Gier, Elizabeth J.; Hoffman, Joel C.; McClain-Counts, Jennifer P.; Miller, Todd W.; Popp, Brian N.; Ross, Steve W.; Sutton, Tracey T.

2012-01-01

The δ15N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer trophic connectivity. We undertook a novel cross-basin comparison of trophic position in two ecologically well-characterized and different groups of dominant mid-water fish consumers using amino acid nitrogen isotope compositions. We found that trophic positions estimated from the δ15N values of individual amino acids are nearly uniform within both families of these fishes across five global regions despite great variability in bulk tissue δ15N values. Regional differences in the δ15N values of phenylalanine confirmed that bulk tissue δ15N values reflect region-specific water mass biogeochemistry controlling δ15N values at the base of the food web. Trophic positions calculated from amino acid isotopic analyses (AA-TP) for lanternfishes (family Myctophidae) (AA-TP ~2.9) largely align with expectations from stomach content studies (TP ~3.2), while AA-TPs for dragonfishes (family Stomiidae) (AA-TP ~3.2) were lower than TPs derived from stomach content studies (TP~4.1). We demonstrate that amino acid nitrogen isotope analysis can overcome shortcomings of bulk tissue isotope analysis across biogeochemically distinct systems to provide globally comparative information regarding marine food web structure.

Natural and built environmental exposures on children's active school travel: A Dutch global positioning system-based cross-sectional study.

PubMed

Helbich, Marco; Emmichoven, Maarten J Zeylmans van; Dijst, Martin J; Kwan, Mei-Po; Pierik, Frank H; Vries, Sanne I de

2016-05-01

Physical inactivity among children is on the rise. Active transport to school (ATS), namely walking and cycling there, adds to children's activity level. Little is known about how exposures along actual routes influence children's transport behavior. This study examined how natural and built environments influence mode choice among Dutch children aged 6-11 years. 623 school trips were tracked with global positioning system. Natural and built environmental exposures were determined by means of a geographic information system and their associations with children's active/passive mode choice were analyzed using mixed models. The actual commuted distance is inversely associated with ATS when only personal, traffic safety, and weather features are considered. When the model is adjusted for urban environments, the results are reversed and distance is no longer significant, whereas well-connected streets and cycling lanes are positively associated with ATS. Neither green space nor weather is significant. As distance is not apparent as a constraining travel determinant when moving through urban landscapes, planning authorities should support children's ATS by providing well-designed cities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Continuous GPS : pilot applications - Phase II

DOT National Transportation Integrated Search

2003-08-01

The primary objective of this research was to evaluate the feasibility of applying Global Positioning System (GPS) technology in the study of geotechnical phenomenon by developing, integrating, and test deploying a GPS-based instrumentation package u...

LADOTD GPS technology management plan : tech summary.

DOT National Transportation Integrated Search

2012-02-01

Global Positioning System (GPS) technology has been adopted by diff erent sections within the Louisiana : Department of Transportation and Development (LADOTD) over the last decade with no uniform standards : for their use, procurement, training, and...

Microenvironment Tracker (MicroTrac) Model helps track air quality

EPA Pesticide Factsheets

MicroTrac is a model that uses global positioning system (GPS) data to estimate time of day and duration that people spend in different microenvironments (e.g., indoors and outdoors at home, work, school).

75 FR 12972 - Amendment of Class E Airspace; Rawlins, WY

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-18

... Rawlins, WY, to accommodate aircraft using a new Area Navigation (RNAV) Global Positioning System (GPS... extending upward from 700 feet above the surface to accommodate IFR aircraft executing a new RNAV (GPS...

Medium-Frequency Data Link for Differential NAVSTAR/GPS Broadcasts

DOT National Transportation Integrated Search

1986-06-01

Differential GPS must communicate differential corrections to civilian users of the Global Positioning System. Modulation of existing marine radiobeacons can provide the needed communication link for DGPS, provided the operation of existing radiobeac...

Bioterrorism Preparedness for Infectious Disease

DTIC Science & Technology

2005-01-01

outbreak. The PDC was asked to use its Geographical Information System (GIS) and Global Positioning System (GPS) technology and capabilities to perform data...improvements in the health system . For example, on May 10, 2002, the Hawaii State Department of Health unveiled plans for its long-term dengue fever...management strategy. The plan included a long-term dengue surveillance system statewide, a statewide mosquito population survey, and ongoing vector control

Low Earth orbit communications satellite

NASA Technical Reports Server (NTRS)

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

1992-01-01

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

Experimental Studies of Ageing in Electrolytic Capacitors

DTIC Science & Technology

2010-10-01

mechanisms of electronic components critical avionics systems such as the GPS and INAV are of critical importance. Electrolytic capac- itors and...the Inertial Navigation ( INAV ) system, causing the aircraft to fly off course. In this paper, we present the details of our ageing methodology along...directed towards DC-DC convert- ers in Avionics systems. In these systems the power supply drives a Global Positioning System (GPS) and INAV unit, and

Arduino based radioactive tracking system

NASA Astrophysics Data System (ADS)

Rahman, Nur Aira Abd; Rashid, Mohd Fazlie Bin Abdul; Rahman, Anwar Bin Abdul; Ramlan, Atikah

2017-01-01

There is a clear need to strengthen security measures to prevent any malevolent use or accidental misuse of radioactive sources. Some of these radioactive sources are regularly transported outside of office or laboratory premises for work and consultation purposes. This paper present the initial development of radioactive source tracking system, which combined Arduino microcontroller, Global Positioning System (GPS) and Global System for Mobile communication (GSM) technologies. The tracking system will help the owner to monitor the movement of the radioactive sources. Currently, the system is capable of tracking the movement of radioactive source through the GPS satellite signals. The GPS co-ordinate could either be transmitted to headquarters at fixed interval via Short Messaging Service (SMS) to enable real time monitoring, or stored in a memory card for offline monitoring and data logging.

Hand Pose Estimation by Fusion of Inertial and Magnetic Sensing Aided by a Permanent Magnet.

PubMed

Kortier, Henk G; Antonsson, Jacob; Schepers, H Martin; Gustafsson, Fredrik; Veltink, Peter H

2015-09-01

Tracking human body motions using inertial sensors has become a well-accepted method in ambulatory applications since the subject is not confined to a lab-bounded volume. However, a major drawback is the inability to estimate relative body positions over time because inertial sensor information only allows position tracking through strapdown integration, but does not provide any information about relative positions. In addition, strapdown integration inherently results in drift of the estimated position over time. We propose a novel method in which a permanent magnet combined with 3-D magnetometers and 3-D inertial sensors are used to estimate the global trunk orientation and relative pose of the hand with respect to the trunk. An Extended Kalman Filter is presented to fuse estimates obtained from inertial sensors with magnetic updates such that the position and orientation between the human hand and trunk as well as the global trunk orientation can be estimated robustly. This has been demonstrated in multiple experiments in which various hand tasks were performed. The most complex task in which simultaneous movements of both trunk and hand were performed resulted in an average rms position difference with an optical reference system of 19.7±2.2 mm whereas the relative trunk-hand and global trunk orientation error was 2.3±0.9 and 8.6±8.7 deg respectively.