Note: This page contains sample records for the topic gps navigation system from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Autonomous Navigation System Based on GPS  

Microsoft Academic Search

An autonomous navigation system based on GPS was developed. The system was composed of the under-controlling part and the\\u000a decision-making part; the two parts communicated with each other via wireless data transmission modules. The under-controlling\\u000a part included the ARM7 microprocessor, the wireless data transmission module, the GPS receiver and the mobile quadricycle.\\u000a The decision-making part included the laptop and the

Zhaoxiang Liu; Gang Liu

2007-01-01

2

Global Positioning System (GPS) autonomous navigation  

Microsoft Academic Search

A system description, a discussion of design issues, and performance results obtained from the Aerospace Corporation simulation of the GPS autonomous navigation system (ANS) concept are given. Analysis methods, physical models, and pertinent equations are presented. Measurement data are realistically simulated and include the effects of all known environmental and hardware phenomena affecting performance. Performance under nominal and anomalous conditions

M. P. Ananda; H. Bernstein; K. E. Cunningham; W. A. Feess; E. G. Stroud

1990-01-01

3

Flight test on GPS navigation performance using low cost GPS navigation system  

Microsoft Academic Search

Summary form only given. The author describes a flight test performed in Japan using a GPS (Global Positioning System) navigation system. A low-cost C\\/A code GPS navigation system (Pioneer AVIC-1) which consists of a three-channel sequential receiver and map display was installed on an experimental aircraft together with VOR\\/DME airborne experiment and a baro-altimeter. The data collected are position, velocity

K. Koremura

1992-01-01

4

A research on SLAM aided INS/GPS navigation system  

NASA Astrophysics Data System (ADS)

Simultaneous Localization and Mapping (SLAM) aided INS/GPS navigation system is a landmark based terrain aided autonomous integrated system that has the capability for online map building and simultaneously utilizing the generated map to bind the errors in the Inertial Navigation System (INS) when GPS is not available. If GPS information is available, the SLAM integrated system builds a landmark-based map using an INS/GPS solution. If GPS is not available, the previously newly generated map is used to constrain the INS errors. The SLAM augmented INS/GPS system shows two capabilities of landmark tracking and mapping using GPS information and more importantly, aiding the INS under GPS denied situation. The validity of the proposed method is demonstrated by computer simulation.

Cao, Menglong; Cui, Pingyuan

2007-11-01

5

The GPS integrated navigation and attitude-determination system (GINAS)  

NASA Astrophysics Data System (ADS)

When the European Columbus Free-Flying Laboratory is orbiting the earth at a speed of 7 km/s, the Global Positioning System (GPS) will allow its instantaneous position to be determined on-board, independently of the ground, to an accuracy of better than 100 m. When the European spaceplane Hermes and the Columbus elements are performing rendezvous maneuvers, they will also be relying on GPS measurements to compute the remaining distance to contact. For the first flight of Hermes itself, there will be no pilot on board and GPS-based navigation will be used for this first mission and the landing. This paper describes the results of GPS field-measurement experiments conducted at ESTEC's radio-navigation testbed laboratory, including a novel 'GPS integrated navigation and attitude-determination system'.

Lucas, R.; Martin-Neira, M.

6

Space Shuttle application of a GPS navigation system  

Microsoft Academic Search

The application of GPS navigation to the Shuttle system will provide an autonomous navigation capability with continuous real-time state vector updates. This, in turn, will significantly increase mission effectiveness, improve propellant management, reduce postflight data reduction time for earth resource applications, and reduce risk margins in abort and contingency landing situations. In this paper, a brief introduction to the STS

A. van Leeuwen

1980-01-01

7

Drive design for ship GPS navigation equipment based on Linux operating system  

Microsoft Academic Search

This paper introduces the drive design for the GPS and LCD modules in ship GPS navigation system realized by adopting the embedded processor with an ARM920T kernel and the Linux operating system design. This design adopts GPS module and TFT LCD module. Drive development of the LCD and GPS modules in GPS navigation system is very important. TFT LCD module

Pan Hongyan; He Hong; Jia Hengtian

2010-01-01

8

Comparison of availability Galileo, GPS and a combined Galileo/GPS navigation systems  

NASA Astrophysics Data System (ADS)

Galileo satellites have been planned to be launched in 2006 by the European Union. Launching these satellites will double the number of positioning satellites currently accessible to users. As a consequence, accuracy and reliability will be improved dramatically. Besides accuracy and reliability, availability is also used for quantification of a Global Navigation Satellite System performance. This paper briefly describes the constellation of space segment of the proposed Galileo navigation system in comparison with the well-known Globabl Positioning System (GPS). Availability of GPS, Galileo and Galileo/GPS satellites are then formulated in terms of Satellite Appearance Distribution Function (SADF). Achievable accuracy in horizontal and vertical positions and timing are expressed using the respective Dilution of Precisions based on the derived mathematical formulation.

Wang, Jiexian

9

Development of a GPS\\/INS\\/MAG navigation system and waypoint navigator for a VTOL UAV  

Microsoft Academic Search

Unmanned aerial vehicles (UAV) can be used for versatile surveillance and reconnaissance missions. If a UAV is capable of flying automatically on a predefined path the range of possible applications is widened significantly. This paper addresses the development of the integrated GPS\\/INS\\/MAG navigation system and a waypoint navigator for a small vertical take-off and landing (VTOL) unmanned four-rotor helicopter with

Oliver Meister; Ralf Mönikes; Jan Wendel; Natalie Frietsch; Christian Schlaile; Gert F. Trommer

2007-01-01

10

Alternate of GPS for ballistic vehicle navigation  

Microsoft Academic Search

Integrated navigation technology, employing inertial navigation system (INS) and Global Positioning System (GPS), has attained the level of state-of-the-art for navigation of ground vehicles, ships, air and space vehicles. Very accurate navigation solution is achievable by employing data fusion techniques for optimal combination of navigation data from INS and GPS. The likelihood that GPS may be denied to the user

Farid Gul; Jiancheng Fang

2006-01-01

11

Autonomous Reconfigurable GPS/INS Navigation and Pointing System for Rendezvous and Docking.  

National Technical Information Service (NTIS)

This paper describes the results of an integrated navigation and pointing system software development effort sponsored by the NASA MSFC through a SBIR Phase 2 Program. The integrated Global Positioning System (GPS)/Inertial Navigation System (INS) impleme...

T. N. Upadhyay S. Cotterill A. W. Deaton

1991-01-01

12

Performance Trials of an Integrated Loran\\/GPS\\/IMU Navigation System, Part II  

Microsoft Academic Search

The 2001 Volpe National Transportation Systems Center report on GPS vulnerabilities identified Loran-C as one possible backup system for GPS. The Federal Aviation Administration (FAA) observed in its recently completed Navigation and Landing Transition Study that Loran-C, as an independent radio navigation system, is theoretically the best backup for GPS; however, this study also observed that Loran-C's potential benefits hinge

Gregory Johnson; Ruslan Shalaev; Christian Oates

2005-01-01

13

Development of a GPS/INS/MAG navigation system and waypoint navigator for a VTOL UAV  

NASA Astrophysics Data System (ADS)

Unmanned aerial vehicles (UAV) can be used for versatile surveillance and reconnaissance missions. If a UAV is capable of flying automatically on a predefined path the range of possible applications is widened significantly. This paper addresses the development of the integrated GPS/INS/MAG navigation system and a waypoint navigator for a small vertical take-off and landing (VTOL) unmanned four-rotor helicopter with a take-off weight below 1 kg. The core of the navigation system consists of low cost inertial sensors which are continuously aided with GPS, magnetometer compass, and a barometric height information. Due to the fact, that the yaw angle becomes unobservable during hovering flight, the integration with a magnetic compass is mandatory. This integration must be robust with respect to errors caused by the terrestrial magnetic field deviation and interferences from surrounding electronic devices as well as ferrite metals. The described integration concept with a Kalman filter overcomes the problem that erroneous magnetic measurements yield to an attitude error in the roll and pitch axis. The algorithm provides long-term stable navigation information even during GPS outages which is mandatory for the flight control of the UAV. In the second part of the paper the guidance algorithms are discussed in detail. These algorithms allow the UAV to operate in a semi-autonomous mode position hold as well an complete autonomous waypoint mode. In the position hold mode the helicopter maintains its position regardless of wind disturbances which ease the pilot job during hold-and-stare missions. The autonomous waypoint navigator enable the flight outside the range of vision and beyond the range of the radio link. Flight test results of the implemented modes of operation are shown.

Meister, Oliver; Mönikes, Ralf; Wendel, Jan; Frietsch, Natalie; Schlaile, Christian; Trommer, Gert F.

2007-05-01

14

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

Microsoft Academic Search

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 Lewis

R. C. Hart

15

The performance analysis of a real-time integrated INS/GPS vehicle navigation system with abnormal GPS measurement elimination.  

PubMed

The integration of an Inertial Navigation System (INS) and the Global Positioning System (GPS) is common in mobile mapping and navigation applications to seamlessly determine the position, velocity, and orientation of the mobile platform. In most INS/GPS integrated architectures, the GPS is considered to be an accurate reference with which to correct for the systematic errors of the inertial sensors, which are composed of biases, scale factors and drift. However, the GPS receiver may produce abnormal pseudo-range errors mainly caused by ionospheric delay, tropospheric delay and the multipath effect. These errors degrade the overall position accuracy of an integrated system that uses conventional INS/GPS integration strategies such as loosely coupled (LC) and tightly coupled (TC) schemes. Conventional tightly coupled INS/GPS integration schemes apply the Klobuchar model and the Hopfield model to reduce pseudo-range delays caused by ionospheric delay and tropospheric delay, respectively, but do not address the multipath problem. However, the multipath effect (from reflected GPS signals) affects the position error far more significantly in a consumer-grade GPS receiver than in an expensive, geodetic-grade GPS receiver. To avoid this problem, a new integrated INS/GPS architecture is proposed. The proposed method is described and applied in a real-time integrated system with two integration strategies, namely, loosely coupled and tightly coupled schemes, respectively. To verify the effectiveness of the proposed method, field tests with various scenarios are conducted and the results are compared with a reliable reference system. PMID:23955434

Chiang, Kai-Wei; Duong, Thanh Trung; Liao, Jhen-Kai

2013-08-15

16

The Performance Analysis of a Real-Time Integrated INS/GPS Vehicle Navigation System with Abnormal GPS Measurement Elimination  

PubMed Central

The integration of an Inertial Navigation System (INS) and the Global Positioning System (GPS) is common in mobile mapping and navigation applications to seamlessly determine the position, velocity, and orientation of the mobile platform. In most INS/GPS integrated architectures, the GPS is considered to be an accurate reference with which to correct for the systematic errors of the inertial sensors, which are composed of biases, scale factors and drift. However, the GPS receiver may produce abnormal pseudo-range errors mainly caused by ionospheric delay, tropospheric delay and the multipath effect. These errors degrade the overall position accuracy of an integrated system that uses conventional INS/GPS integration strategies such as loosely coupled (LC) and tightly coupled (TC) schemes. Conventional tightly coupled INS/GPS integration schemes apply the Klobuchar model and the Hopfield model to reduce pseudo-range delays caused by ionospheric delay and tropospheric delay, respectively, but do not address the multipath problem. However, the multipath effect (from reflected GPS signals) affects the position error far more significantly in a consumer-grade GPS receiver than in an expensive, geodetic-grade GPS receiver. To avoid this problem, a new integrated INS/GPS architecture is proposed. The proposed method is described and applied in a real-time integrated system with two integration strategies, namely, loosely coupled and tightly coupled schemes, respectively. To verify the effectiveness of the proposed method, field tests with various scenarios are conducted and the results are compared with a reliable reference system.

Chiang, Kai-Wei; Duong, Thanh Trung; Liao, Jhen-Kai

2013-01-01

17

Autonomous reconfigurable GPS/INS navigation and pointing system for rendezvous and docking  

NASA Astrophysics Data System (ADS)

This paper describes the results of an integrated navigation and pointing system software development effort sponsored by the NASA MSFC through a SBIR Phase 2 Program. The integrated Global Positioning System (GPS)/Inertial Navigation System (INS) implements an autonomous navigation filter that is reconfigurable in real-time to accommodate mission contingencies. An onboard expert system monitors the spacecraft status and reconfigures the navigation filter accordingly, to optimize the system performance. The navigation filter is a multi-mode Kalman filter to estimate the spacecraft position, velocity, and attitude. Three different GPS-based attitude determination techniques, namely, velocity vector matching, attitude vector matching, and interferometric processing, are implemented to encompass different mission contingencies. The integrated GPS/INS navigation filter will use any of these techniques depending on the mission phase and the state of the sensors. The first technique, velocity vector matching, uses the GPS velocity measurement to estimate the INS velocity errors and exploits the correlation between INS velocity and attitude errors to estimate the attitude. The second technique, attitude vector matching, uses INS gyro measurements and GPS carrier phase (integrated Doppler) measurements during a spacecraft rotation maneuver to determine the attitude. Both of these techniques require only one GPS antenna onboard to determine the spacecraft attitude. The third technique, interferometric processing, requires use of multiple GPS antennae. In order to determine 3-axis body attitude, three GPS antennae (2 no-coplanor baselines) are required.

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

18

The need for conformity in GPS navigation and pilotage systems  

Microsoft Academic Search

There has been a steady growth in the development of satellite-based vessel tracking systems and electronics aids for pilotage, especially on inland waterways. The Global Positioning System (GPS) is a key element in many of the activities that have been undertaken. The global aspects of the technology, however, do not ensure conformity among emerging systems. It is time to make

1998-01-01

19

The theoretical and experimental validation of the GPS-INS-STAR hybrid navigation system concept  

NASA Astrophysics Data System (ADS)

The theoretical and experimental validation of the GPS-INS-STAR hybrid navigation system is performed. The GPS-INS-STAR hybrid navigation system (Tanabe, 1984, 1985) consists of a GPS receiver, an inertial navigation system (INS), and a STAR image sensor. In this concept, the system integrates a high positioning performance of the GPS system, an accurate attitude determination capability of the STAR image sensor, and the INS signal with a wide bandwidth results in a complete 6-DOF autonomous navigation system. The validation of the concept was performed by Tanabe (1988). The present paper extends the experiment further, where the various configurations of the hybrid system are compared. The paper also shows a theoretical description of the experimental results.

Harigae, M.; Tanabe, T.

20

Integrated GPS/INS navigation system design for autonomous spacecraft rendezvous  

NASA Astrophysics Data System (ADS)

The goal of the NASA Space Launch Initiative (SLI) program is to advance the technologies for the next generation reusable launch vehicle (RLV). The SLI program has identified automated rendezvous and docking as an area requiring further research and development. Currently, the Space Shuttle uses a partially manual system for rendezvous, but a fully automated system could be safer and more reliable. Previous studies have shown that it is feasible to use the Global Positioning System (GPS) for spacecraft navigation during rendezvous with the International Space Station (ISS). However, these studies have not accounted for the effects of GPS signal blockage and multipath in the vicinity of the ISS, which make a GPS-only navigation system less accurate and reliable. One possible solution is to combine GPS with an inertial navigation system (INS). The integration of GPS and INS can be achieved using a Kalman filter. GPS/INS systems have been used in aircraft for many years and have also been used in launch vehicles. However, the performance of GPS/INS systems in orbit and during spacecraft rendezvous has not been characterized. The primary objective of this research is to evaluate the ability of an integrated GPS/INS to provide accurate navigation solutions during a rendezvous scenario where the effects of ISS signal blockage, multipath and delta-v maneuvers degrade GPS-only navigation. In order to accomplish this, GPS-only and GPS/INS Kalman filters have been developed for both absolute and relative navigation, as well as a new statistical multipath model for spacecraft operating near the ISS. Several factors that affect relative navigation performance were studied, including: filter tuning, GPS constellation geometry, rendezvous approach direction, and inertial sensor performance. The results showed that each of these factors has a large impact on relative navigation performance. Finally, it has been demonstrated that a GPS/INS system based on medium accuracy aircraft avionics-grade inertial sensors does not provide adequate relative navigation performance for rendezvous with the ISS unless accelerometer thresholding is used. However, the use of state-of-the-art inertial navigation sensors provides relative position accuracy which is adequate for rendezvous with ISS if an additional rendezvous sensor is included.

Gaylor, David Edward

2003-10-01

21

An outdoor navigation system using GPS and inertial platform  

Microsoft Academic Search

The use of global positioning system (GPS) in outdoor localization is quite a common solution in large environments where no other reference is available and there are not so demanding positioning requirements. Of course, fine motion without the use of an expensive differential device is not an easy task, even now that available precision has been greatly improved as the

Stefano Panzieri; Federica Pascucci; Giovanni Ulivi

2002-01-01

22

Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS)/Precise Positioning Service (PPS).  

National Technical Information Service (NTIS)

This Military Standard Order (MSO) prescribes the minimum performance standard that airborne supplemental area navigation equipment using Global Positioning System (GPS) / Precise Positioning Service (PPS) must meet in order to be identified with the appl...

2005-01-01

23

Airborne Supplemental Navigation Equipment Using The Global Positioning System (GPS) Precise Positioning Service (PPS).  

National Technical Information Service (NTIS)

This Military Standard Order (MSO) prescribes the minimum performance standard that airborne supplemental area navigation equipment using Global Positioning System (GPS) / Precise Positioning Service (PPS) must meet in order to be identified with the appl...

2002-01-01

24

GPS-INS-STAR - A navigation system for the era of space autonomy  

NASA Astrophysics Data System (ADS)

Experimental validation of the GPS-INS-STAR hybrid navigation system concept is performed. First, an INS-STAR hybrid navigation system is constructed on the 3-axis motion table to verify the performance of its attitude loop. A GPS-INS hybrid navigation system is then installed on a car, and its translational performance is evaluated. Each result of the experiments is verified by theoretical analysis, and its feasibility for space application is evaluated. Through the experiments, the concept of the autonomous hybrid navigation is validated, and its potential in space autonomy is indicated.

Tanabe, Toru; Kitamura, Toshiaki; Ikeuchi, Masayuki; Tanaka, Toshiyuki; Akasaka, Akira

25

Effects of Large Magnetic Storms on Communication and GPS Navigation Systems at Middle and Equatorial Latitudes  

Microsoft Academic Search

Large magnetic storms with Dst exceeding 100 nanotesla cause a prompt penetration of electric fields into the mid- latitude and the equatorial ionosphere. The resulting steep spatial TEC gradients and scintillation in GPS receivers impact the Wide Area Augmentation System (WAAS), which is to provide GPS based navigation to aircraft. At the magnetic equator, the enhanced eastward electric field causes

Santimay Basu; Sunanda Basu

26

Real-Time Implementation of GPS Aided Low-Cost Strapdown Inertial Navigation System  

Microsoft Academic Search

This work details the study, development, and experimental implementation of GPS aided strapdown inertial navigation system\\u000a (INS) using commercial off-the-shelf low-cost inertial measurement unit (IMU). The data provided by the inertial navigation\\u000a mechanization is fused with GPS measurements using loosely-coupled linear Kalman filter implemented with the aid of MPC555\\u000a microcontroller. The accuracy of the estimation when utilizing a low-cost inertial

L. R. Sahawneh; M. A. Al-Jarrah; K. Assaleh; Mamoun F. Abdel-Hafez

2011-01-01

27

FPGA-based real-time embedded system for RISS/GPS integrated navigation.  

PubMed

Navigation algorithms integrating measurements from multi-sensor systems overcome the problems that arise from using GPS navigation systems in standalone mode. Algorithms which integrate the data from 2D low-cost reduced inertial sensor system (RISS), consisting of a gyroscope and an odometer or wheel encoders, along with a GPS receiver via a Kalman filter has proved to be worthy in providing a consistent and more reliable navigation solution compared to standalone GPS receivers. It has been also shown to be beneficial, especially in GPS-denied environments such as urban canyons and tunnels. The main objective of this paper is to narrow the idea-to-implementation gap that follows the algorithm development by realizing a low-cost real-time embedded navigation system capable of computing the data-fused positioning solution. The role of the developed system is to synchronize the measurements from the three sensors, relative to the pulse per second signal generated from the GPS, after which the navigation algorithm is applied to the synchronized measurements to compute the navigation solution in real-time. Employing a customizable soft-core processor on an FPGA in the kernel of the navigation system, provided the flexibility for communicating with the various sensors and the computation capability required by the Kalman filter integration algorithm. PMID:22368460

Abdelfatah, Walid Farid; Georgy, Jacques; Iqbal, Umar; Noureldin, Aboelmagd

2011-12-22

28

Testing and Evaluation of an Integrated GPS/INS System for Small AUV Navigation.  

National Technical Information Service (NTIS)

A Small AUV Navigation System (SANS) is being developed at the Naval Postgraduate School. The SANS is an integrated GPS/INS navigation system composed of low-cost and small-size components. It is designed to demonstrate the feasibility of using a low-cost...

E. R. Bachmann R. B. McGhee R. H. Whalen R. L. Roberts X. Yun

1999-01-01

29

An experimental validation of magnetometer integration into a GPS-aided helicopter UAV navigation system  

Microsoft Academic Search

This paper considers the integration of a triaxial magnetometer sensor into an existing navigation system for a helicopter Unmanned Aerial Vehicle (UAV). An existing inertial navigation system uses triaxial accelerometer and rate gyro measurements and is aided by GPS. A novel calibration method for the magnetometer is implemented. The integration of the calibrated magnetometer into the existing design is experimentally

Martin Barczyk; Michael Jost; David R. Kastelan; Alan F. Lynch; Kim D. Listmann

2010-01-01

30

Invariant Extended Kalman Filter design for a magnetometer-plus-GPS aided inertial navigation system  

Microsoft Academic Search

We introduce a magnetometer-plus-GPS aided inertial navigation system for a helicopter UAV. A nonlinear observer is required to estimate the navigation states, typically an Extended Kalman Filter (EKF). A novel approach is the invariant observer, a constructive design method applicable to systems possessing symmetries. We review the theory and design an invariant observer for our example. Using an invariant observer

Martin Barczyk; Alan F. Lynch

2011-01-01

31

GPS/INS generalized evaluation tool (GIGET) for the design and testing of integrated navigation systems  

NASA Astrophysics Data System (ADS)

GIGET, the GPS/INS Generalized Evaluation Tool, experimentally tests, evaluates, and compares navigation systems that combine the Global Positioning System (GPS) with Inertial Navigation Systems (INS). GPS is a precise and reliable navigation aid but can be susceptible to interference, multi-path, or other outages. An INS is very accurate over short periods, but its errors drift unbounded over time. Blending GPS with INS can remedy the performance issues of both. However, there are many types of integration methods, and sensors vary greatly, from the complex and expensive, to the simple and inexpensive. It is difficult to determine the best combination for any desired application; most of the integrated systems built to date have been point designs for very specific applications. GIGET aids in the selection of sensor combinations for any general application or set of requirements; hence, GIGET is the generalized way to evaluate the performance of integrated systems. GIGET is a combination of easily re-configurable hardware and analysis tools that can provide real-time comparisons of multiple integrated navigation systems. It includes a unique, multi-antenna GPS receiver and a tactical grade inertial measurement unit. GIGET is quickly outfitted onto a variety of vehicle platforms to experimentally test and compare navigation performance. In side-by-side experiments, GIGET compares loosely coupled and tightly coupled integrated navigation schemes blending navigation, tactical, or automotive grade inertial sensors with GPS. These results formulate a trade study to map previously uncharted territory of the GPS/INS space that trades accuracy and expense versus complexity of design. These GIGET results can be used to determine acceptable sensor quality in these integration methods for a variety of dynamic environments. As a demonstration of its utility as a hardware evaluation tool, GIGET is used to design a navigation system on the DragonFly Unmanned Air Vehicle (UAV). The DragonFly UAV is a test-bed for autonomous control experiments. GIGET was flown on the DragonFly to evaluate different integrated navigation combinations in the UAV's dynamic environment. GIGET shows that a loosely coupled, single-antenna GPS system with a moderately priced inertial unit will provide the consistent navigation currently needed on the DragonFly.

Gautier, Jennifer Denise

32

The design of GPS\\/GPRS navigation and monitoring system based on GIS  

Microsoft Academic Search

Vehicle Monitoring and Navigation System (VMNS) is the result of the rapid development of science and technology, which developed into a certain stage. This system, which integrated with Geographical Information System (GIS), Global Position System (GPS) and Wireless Communication Technology, has been widely used in many fields, like public security, fire-fighting, finance, transportation, tourism and etc. This paper successfully worked

Dongli Wang; Jing Li

2010-01-01

33

Carin en GPS: De Combinatie van Dead-Reckoning, MAP-Matching en Satellietplaatsbepaling in een Hybride Autonavigatiesysteem (Carin and GPS: The Combination of Dead Reckoning, MAP Matching and Satellite Navigation in a Hybrid Automobile Navigation System).  

National Technical Information Service (NTIS)

The possible coupling between the Philips Carin (car information and navigation system) automobile navigation system and the Global Positioning System (GPS)/Navstar satellite positioning system was investigated. The Carin system is based on a combination ...

R. L. G. Lemmens

1989-01-01

34

Verification of Robustified Kalman Filters for the Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) Data.  

National Technical Information Service (NTIS)

The purpose of this research is to compare the effects of two filtering routines which may be used to integrate Inertial Navigation System (INS) and Global Positioning System (GPS) data to determine certain state vector elements. The two filtering routine...

J. W. Haak

1994-01-01

35

Speech Enabled GPS Based Navigation System in Hungarian for Blind People on Symbian Based Mobile Devices  

Microsoft Academic Search

The aim of the present study is to create a speech enabled GPS based navigation system for blind people. The speech user interface was designed in consultation with the Hungarian Association of Blind and Visually Impaired People. The application will satisfy the special needs of the target user group. It is also a particular aim to use only easily accessible,

B. Tóth; G. Németh

36

Land-vehicle navigation using GPS  

Microsoft Academic Search

The Global Positioning System (GPS) has made navigation systems practical for a number of land-vehicle navigation applications. Today, GPS-based navigation systems can be found in motor vehicles, farming and mining equipment, and a variety of other land-based vehicles (e.g., golf carts and mobile robots). Each of these applications is discussed and the reader is introduced to some of the issues

ERIC ABBOTT; DAVID POWELL

1999-01-01

37

Overcoming urban GPS navigation challenges through the use of MEMS inertial sensors and proper verification of navigation system performance  

NASA Astrophysics Data System (ADS)

This research proposes several means to overcome challenges in the urban environment to ground vehicle global positioning system (GPS) receiver navigation performance through the integration of external sensor information. The effects of narrowband radio frequency interference and signal attenuation, both common in the urban environment, are examined with respect to receiver signal tracking processes. Low-cost microelectromechanical systems (MEMS) inertial sensors, suitable for the consumer market, are the focus of receiver augmentation as they provide an independent measure of motion and are independent of vehicle systems. A method for estimating the mounting angles of an inertial sensor cluster utilizing typical urban driving maneuvers is developed and is able to provide angular measurements within two degrees of truth. The integration of GPS and MEMS inertial sensors is developed utilizing a full state navigation filter. Appropriate statistical methods are developed to evaluate the urban environment navigation improvement due to the addition of MEMS inertial sensors. A receiver evaluation metric that combines accuracy, availability, and maximum error measurements is presented and evaluated over several drive tests. Following a description of proper drive test techniques, record and playback systems are evaluated as the optimal way of testing multiple receivers and/or integrated navigation systems in the urban environment as they simplify vehicle testing requirements.

Vinande, Eric T.

38

GPS-based position control and waypoint navigation system for quadrocopters  

Microsoft Academic Search

Motivation for the investigation of position and waypoint controllers is the demand for Unattended Aerial Systems (UAS) capable of fulfilling e.g. surveillance tasks in contaminated or in inaccessible areas. Hence, this paper deals with the development of a 2D GPS-based position control system for 4 Rotor Helicopters able to keep positions above given destinations as well as to navigate between

Tim Puls; Markus Kemper; Reimund Küke; Andreas Hein

2009-01-01

39

Application of adaptive Kalman filtering algorithm in IMU\\/GPS integrated navigation system  

Microsoft Academic Search

The IMU(inertial measurement unit) error equations in the earth fixed coordinates are introduced firstly. A fading Kalman\\u000a filtering is simply introduced and its shortcomings are analyzed, then an adaptive filtering is applied in IMU\\/GPS integrated\\u000a navigation system, in which the adaptive factor is replaced by the fading factor. A practical example is given. The results\\u000a prove that the adaptive filter

Weiguang Gao; Yuanxi Yang; Xianqiang Cui; Shuangcheng Zhang

2007-01-01

40

Integration of a GPS aided Strapdown Inertial Navigation System for Land Vehicles  

Microsoft Academic Search

Abstract The estimation accuracy of a low-cost inertial navigation system (INS) is limited by the accuracy of the used sensors and the imperfect mathematical modeling of the error sources. By fusing the INS data with GPS data, the errors can be bounded and the accuracy increases considerably. In this project, a low-cost in-house constructed inertial measurement unit (IMU) and an

ADRIAN SCHUMACHER

2006-01-01

41

Ensuring GPS navigation integrity using receiver autonomous integrity monitoring  

Microsoft Academic Search

The many advantages of Global Positioning System (GPS) based navigation have created a tremendous amount of interest in using GPS as the primary navigation aid onboard commercial and civil aircraft. Even in the presence of Selective Availability, the accuracy of GPS is sufficient to guide aircraft point-to-point between airports without requiring other navigation aids such as VOR or DME. Unfortunately,

William R. Michalson

1995-01-01

42

Aiding GPS With Additional Satellite Navigation Services.  

National Technical Information Service (NTIS)

In modern warfare navigation services are very important. GPS is currently providing service for accurate navigation, except in some areas, especially urban areas, where GPS signals cannot always be tracked by users. In these cases some additional navigat...

Y. A. Mutlu

2010-01-01

43

Application of integrated autonomous microwave position finding system and GPS for UAV navigation  

Microsoft Academic Search

Unmanned aerial vehicles (UAV) have widespread applications recently, both in commercial and government oriented fields, and demands they have to fullfil are tough. One of the prerequisite demands is as much as possible precise positioning and navigation during all phases of mission. Application of technologies such as GPS give opportunity to improve performance of UAV navigation, especially in cases when

V. Smiljiakovic; Z. T. Golubicic; Predrag S. ManojloviC; Dragan D. ObradoviC; Nenad V. PopoviC; Z. B. Zivanovic

2003-01-01

44

New integration scheme of GPS-INS hybrid navigation system for maneuvering spacecraft  

NASA Astrophysics Data System (ADS)

Integration schemes of the GPS with INS are considered. In the conventional navigation scheme, information from INS is usually used in the form of velocity-aiding signal to the receiver-tracking loops. In this paper, a new integration scheme is proposed which performs more effective information exchange so that it is more tolerant to RF interferences and unmodeled INS errors than the conventional scheme. These results are obtained from theoretical analyses and confirmed by computer simulations including GPS receiver dynamics.

Tanabe, T.; Harigae, M.; Koyama, H.

45

Terrestrial navigation based on integrated GPS and INS  

NASA Astrophysics Data System (ADS)

The Global Positioning System (GPS) and Inertial Navigation System (INS) have complimentary features that can be exploited in an integrated system, thus resulting in improved navigation performance. The INS is able to provide accurate aiding data on short-term vehicle dynamics, while the GPS provides accurate data on long-term vehicle dynamics. In this paper, a complete solution is presented for terrestrial navigation based on integrated GPS and INS using Kalman filtering technique.

Ge, Sam S.; Goh, Terence K.; Jiang, T. Y.; Koopman, R.; Chan, S. W.; Fong, A. M.

1998-07-01

46

High-Performance Navigation System with Integration of Low-Precision MEMS INS and General-Purpose GPS  

NASA Astrophysics Data System (ADS)

In this paper, we propose a new configuration for a strap-down, integrated INS/GPS (Inertial Navigation System/Global Positioning System) navigation system. It is aimed at general-purpose use, and utilizes MEMS (microelectromechanical system) sensors and a quaternion-based model that enable the development of a precise system with a degree of portability that traditional INS/GPS devices cannot achieve. In order to examine the effectiveness of our system, we built a prototype instrument and performed an experiment comparing its performance with GAIA, an ultra high-precision INS/GPS device developed by the Japan Aerospace Exploration Agency (JAXA). The results show that our small, light and low-cost system is applicable to general-purpose use, having a position error of only a few meters and under 2 degrees of roll and pitch error, which is sufficiently precise for the general control of moving objects.

Naruoka, Masaru; Tsuchiya, Takeshi

47

The Design of Embedded GPS Navigation System Based on Internet Structure  

Microsoft Academic Search

Combining wireless devices, GPS, and client-server system in the Internet, we could run a current guidance system and query all the computerized data. The problem in using GPS in Taiwan is the accuracy between actual latitude and longitude position and the data in the coordinate system, therefore when combining real data we have to take into account the coordinate system

Shih-I Chen; Fu-Chien Kao

48

76 FR 50808 - Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Navigation Equipment Using the Global Positioning System...cancel Technical Standard Order (TSO)- C129a, Airborne...Navigation Equipment Using the Global Positioning System...Navigation Equipment Using the Global Positioning System...FOR FURTHER INFORMATION CONTACT: Mr. Kevin...

2011-08-16

49

High accuracy navigation and landing system using GPS\\/IMU system integration  

Microsoft Academic Search

In this paper, the accuracy, integrity and continuity of function requirements for automatic landing systems using satellite navigation systems are discussed. Such a landing system is the integrated navigation and landing system (INLS) developed by Deutsche Aerospace (DASA\\/Ulm, Germany). The system concepts of the INLS are presented. It is shown how an INLS, based on system integration of a satellite

J. Meyer-Hilberg; T. Jacob

1994-01-01

50

GPS-based Land Vehicle Navigation System Assisted by a Low-Cost Gyro-Free INS Using Neural Network  

NASA Astrophysics Data System (ADS)

GPS-based land vehicle navigation systems are subject to signal fading in urban areas and require aid from other enabling sensors. A low-cost gyro-free inertial navigation system (INS) without accumulated attitude errors and complicated initializations could be an effective solution to the problem. This paper investigates a Constrained Navigation Algorithm (CNA) and the Artificial Neural Network (ANN) technique to compensate velocity output from a gyro-free INS. The vehicle's heading will be calibrated by a full circle test so that the magnetometer's bias and scale factor error could be removed. Experiments with a vehicle driven over level terrain have been conducted to assess the performance of the compensated gyro-free INS solutions. The effect of the architecture of Neural Network on prediction performance has also been discussed as well as the applicability of the proposed solution to land vehicle navigation with GPS outages.

Wang, Jau-Hsiung; Gao, Yang

2004-09-01

51

A Real-Time Information System for BRT Based on GPS\\/Signpost Compound Navigation Technology  

Microsoft Academic Search

The initial real-time information system for Bus Rapid Transit (BRT) is based on Global Positioning System (GPS) in Ji'nan, it can't provide accurate real-time information of buses arrival\\/departure at stop, and missing data of GPS is often found, especially under elevated highway or in bad weather. The papers put forward a new way to provide real-time transit information for BRT

Chong-hua Zhou; Zuo-gang Gao

2010-01-01

52

Multiple mobile robot navigation using the indoor global positioning system (iGPS)  

Microsoft Academic Search

We propose a practical method of multiple mobile robot navigation aimed at the realization of service robots that deliver letters, parcels and documents in an office building. For robust execution of delivery tasks by mobile robots, navigation is important, and localization of robots is a key function for designing robust navigation. We developed a global positioning system for indoor mobile

Yoshiro HADA; Kunikatsu TAKASE

2001-01-01

53

GPS computer navigators to shorten EMS response and transport times.  

PubMed

GPS (global positioning satellite system to determine one's position on earth) units have become inexpensive and compact. The purpose of this study is to assess the effectiveness of a GPS enhanced computer street map navigator to improve the ability of EMS drivers in an urban setting to locate their destination and shorten response times. For part I, residential addresses in the city were randomly selected from a telephone directory. Two driver/navigator teams were assigned to drive to the address adhering to speed limits. One team used a standard street map, whereas the other team used a GPS computer navigator. The travel time and distance of the runs were compared. For part II, the computer GPS navigator was placed on an ambulance to supplement their normal methods of navigation to find the address requesting EMS. After the run was completed, EMS providers were interviewed to determine their opinion of whether the GPS navigator was helpful. For part I the results showed that in the 29 initial test runs, comparing the GPS team versus the standard map team, the mean distances traveled were 8.7 versus 9.0 kilometers (not significant) and the mean travel times were 13.5 versus 14.6 minutes (P=.02), respectively. The GPS team arrived faster in 72% runs. For part II the results showed that most EMS providers surveyed noted that the GPS computer navigator enhanced their ability to find the destination and all EMS providers acknowledged that it would enhance their ability to find a destination in an area in which they were unfamiliar. These results suggest that a portable GPS computer navigator system is helpful and can enhance the ability of prehospital care providers to locate their destination. Because these units are accurate and inexpensive, GPS computer navigators may be a valuable tool in reducing pre-hospital transport times. PMID:11326345

Ota, F S; Muramatsu, R S; Yoshida, B H; Yamamoto, L G

2001-05-01

54

Precise Near-Earth Navigation with GPS (Global Positioning System): A Survey of Techniques.  

National Technical Information Service (NTIS)

The tracking accuracy of the low earth orbiters (below about 3000 km altitude) can be brought below 10 cm with a variety of differential techniques that exploit the Global Positioning System (GPS). All of these techniques require a precisely known global ...

T. P. Yunck S. C. Wu J. Wu

1987-01-01

55

Evaluating the velocity accuracy of an integrated GPS/INS system: Flight test results. [Global positioning system/inertial navigation systems (GPS/INS)  

SciTech Connect

Verifying the velocity accuracy of a GPS receiver or an integrated GPS/INS system in a dynamic environment is a difficult proposition when many of the commonly used reference systems have velocity uncertainities of the same order of magnitude or greater than the GPS system. The results of flight tests aboard an aircraft in which multiple reference systems simultaneously collected data to evaluate the accuracy of an integrated GPS/INS system are reported. Emphasis is placed on obtaining high accuracy estimates of the velocity error of the integrated system in order to verify that velocity accuracy is maintained during both linear and circular trajectories. Three different reference systems operating in parallel during flight tests are used to independently determine the position and velocity of an aircraft in flight. They are a transponder/interrogator ranging system, a laser tracker, and GPS carrier phase processing. Results obtained from these reference systems are compared against each other and against an integrated real time differential based GPS/INS system to arrive at a set of conclusions about the accuracy of the integrated system.

Owen, T.E.; Wardlaw, R.

1991-01-01

56

An Integrated Navigation System using GPS Carrier Phase for Real-Time Airborne Synthetic Aperture Radar (SAR)  

SciTech Connect

A Synthetic Aperture Radar (SAR) requires accu- rate measurement of the motion of the imaging plat- form to produce well-focused images with minimal absolute position error. The motion measurement (MoMeas) system consists of a inertial measurement unit (IMU) and a P-code GPS receiver that outputs corrected ephemeris, L1 & L2 pseudoranges, and L1 & L2 carrier phase measurements. The unknown initial carrier phase biases to the GPS satellites are modeled as states in an extended Kalman filter and the resulting integrated navigation solution has po- sition errors that change slowly with time. Position error drifts less than 1- cm/sec have been measured from the SAR imagery for various length apertures.

Fellerhoff, J. Rick; Kim, Theodore J.; Kohler, Stewart M.

1999-06-24

57

Design and implementation of embedded GPS navigation software  

NASA Astrophysics Data System (ADS)

A navigation software, which provides positioning and navigation service based on GPS technique, is introduced. This software is designed and realized under the environment of the embedded operating system WindowsCE and can be widely applied to the systems such as ITS (intelligent transportation systems) and LBS (location based services).

Zeng, Zhe; Li, Zhong-Hua; Zhu, Cai-Lian

2004-06-01

58

GPS navigation processing using the IMM-based EKF  

Microsoft Academic Search

This paper presents an interacting multiple model (IMM)-based extended Kalman filter (EKF) approach for the Global Positioning System (GPS) navigation processing. The well-known extended Kalman filter has been widely applied to the GPS navigation processing. The ldquosoft-switchingrdquo IMM estimator obtains its estimate as a weighted sum of the individual estimates from a number of parallel filters matched to different motion

Dah-Jing Jwo; Chien-Hao Tseng

2008-01-01

59

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle  

NASA Astrophysics Data System (ADS)

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.

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

1993-07-01

60

Ubiquitous Navigation Based on Physical Maps and GPS  

Microsoft Academic Search

This work is an improvement of a navigating method which uses only a GPS receiver and a physical map photographed by the embedded camera on a smart phone to build up a ubiquitous navigation system. Instead of the ¡§Two Point Referencing¡¨ approach, a ¡§Three Point Referencing¡¨ method is proposed in this paper, which trades off the need of the ¡§extra¡¨

Yu-Ren Wang; Chun-Yi Tsai; Yao-Chung Chang; Horng-Chang Yang; Ming-Chiao Chen

2012-01-01

61

Spacecraft orbit determination using GPS navigation solutions  

Microsoft Academic Search

The orbit determination using the GPS navigation solutions for the KOMPSAT-1 spacecraft has been studied. The Cowell method of special perturbation theories was employed to develop a precision orbit propagation, and the perturbations due to geopotential, the gravity of the Sun and the Moon, solid Earth tides, ocean tides, the Earth's dynamic polar motion, solar radiation pressure, and atmospheric drag

Jae-Cheol Yoon; Byoung-Sun Lee; Kyu-Hong Choi

2000-01-01

62

Satellite Navigation Systems  

NSDL National Science Digital Library

The Global Positioning System (GPS) has been in operation for several years, and its use is continually rising. GPS is the main satellite navigation system developed by the United States. There are countless applications of this technology, and numerous international efforts are currently underway.The Topcon Positioning Systems company provides an excellent introduction to GPS technology in its online book (1). The first couple chapters describe the evolution of GPS and its fundamentals, and the remaining material focuses on some specific issues. A more advanced tutorial is given through the IBM Web site (2). A brief, free registration is required to view it, and some familiarity with Java is recommended. The European Space Agency provides this page about satellite navigation (3), which describes, among other things, Galileo. This is not the astronomer; Galileo is Europe's version of GPS, scheduled for completion in 2008. Another system, developed by Russia, is detailed on the Space and Technology Web site (4). The short summary describes the 20-year history of the Global Navigation Satellite System (GLONASS), as well as upgrades that are in progress. Differential GPS, a service that is more accurate than standard GPS in areas with poor coverage, is operated by the US Coast Guard Navigation Center (5). Some information about the status of nationwide DGPS expansion is given. Several research and development projects, technology highlights, and GPS implementations are covered on the UNAVCO home page (6). The facility primarily fosters work to expand the applications of satellite navigation. With the wave of kidnapping cases reported across the country, a novel use of GPS is being marketed to keep track of children (7). These portable devices can be worn on the wrist, like a watch, so parents can always know where their kids are. Another news story describes the use of GPS in mining operations (8). The technology allows operators of huge three-story dump trucks to detect obstacles and maneuver the vehicle with only limited visibility.

Leske, Cavin.

2002-01-01

63

Static positioning determination using GPS navigation solution  

NASA Astrophysics Data System (ADS)

The purpose of this work is to use the Kalman filter to estimate the positioning vector of a static landmark from the navigation solutions obtained by GPS receivers. The estimator purpose is to calculate the state vector based in a set of observations. Such a computational algorithm processes measurements to produce a minimum error estimation of a system using knowledge of the dynamic and the measurements, measurement errors, and informations about initial conditions. There are two basic methods in the state estimation process to estimate the state vector: 1) when the state is updated in a reference or epoch instant, using a block of observations obtained during a space of time and in this case it is called batch estimator and the Least Squares method is the most used; 2) when the state vector is updated after processing each observation, in this case, the process is called sequential or recursive estimator and the most commom examples are recursive Least Squares and Kalman filter. In this work the Kalman filter will be used because of its robustness in real time applications, recursive and sequential nature, without unnecessary storage of observations, as they can be processed while being collected, and the convergence is obtained while observations are processed. The dynamical model considers the state vector to be estimated and the dynamic noise is assumed to be a discrete white noise. The observations modeling considers the m observations vector collected, the matrix relating the observations to the state and the observations noise vector. Data were collected using two dual frequency Ashtech Z-12 GPS receivers of geodetic quality, placed at known reference landmarks. A comparison will be done between the estimated state vector and the landmarks geodetic coordinates which were previously surveyed by IBGE. This work aims at performing a preliminary investigation on real time positioning techniques, with can thereafter be extended to navigation of space vehicles, including more complex features of non linear dynamic and the measurements.

Gomes, V. M.; Kuga, H. K.; Lopes, R. V. F.; Chiaradia, A. P. M.

2003-08-01

64

Satellite selection algorithm for combined GPS-Galileo navigation receiver  

Microsoft Academic Search

In the future, integrated GPS-Galileo Navigation Satellite System will expand its applications in many fields. For space robots, it will provide high accuracy and real-time navigation service. As it is well-known, the integrated system will provide twice and more satellites than individual system. Therefore, selecting appropriate satellites from the combined constellation is a very important aspect. Using a reasonable and

Xu Bo; Bingjun Shao

2009-01-01

65

Global Navigation Satellite Systems: A Perspective on Reference Frame Evolution Over the Next Decade With GPS, GLONASS and Galileo  

Microsoft Academic Search

The strategies of the IGS* to optimize the future use of multiple integrated GNSS - GPS and its modernization, the new Galileo, and GLONASS will be discussed. This is particularly important towards sustaining and evolving the precise reference frame maintained by the International Earth Rotation and Reference System's (IERS) International Terrestrial Reference Frame (ITRF). Since 1994, the IGS produces GPS

R. E. Neilan; A. Moore; J. Dow; G. Gendt

2005-01-01

66

GPS - Global Positioning System. Theory and practice  

Microsoft Academic Search

This book shows in comprehensive manner how the Global Positioning System (GPS) works. The use of GPS for precise measurements (i.e. surveying) is treated as well as navigation and attitude determination. The basic mathematical models for various modes of GPS operations and detailed explanation of the practical use of GPS are developed precisely in this book. Additionally, the text shows

B. Hofmann-Wellenhof; H. Lichtenegger; J. Collins

1997-01-01

67

Is H? filtering relevant for correlated noises in GPS navigation?  

Microsoft Academic Search

This paper deals with the issue of correlated noises in GPS navigation. GPS is based on the measure of the propagation delays of satellite signals. Therefore, additional delays induced when traveling through the ionosphere or the troposphere degrade GPS accuracy. These error sources are correlated, both spatially and temporally. Thus, when using an extended Kalman filter as navigation algorithm, these

Audrey Giremus; Eric Grivel; Francis Castanie

2009-01-01

68

Experimental results from an ultra-tightly coupled GPS\\/Galileo\\/WiFi\\/ZigBee\\/MEMS-IMU indoor navigation test system featuring coherent integration times of several seconds  

Microsoft Academic Search

This paper contains selected test results of an indoor positioning prototype system making use of GPS\\/Galileo signals on L1\\/E1 and L5\\/E5a in addition to WiFi data, ZigBee data and a MEMS-based dead reckoning algorithm called pedestrian navigation system (PNS). The system uses a partially coherent ultra-tightly coupled integration scheme. The GNSS signal processing (acquisition and tracking) supports coherent integration times

Thomas Pany; Jón Winkel; Bernhard Riedl; Herbert Niedermeier; Bernd Eissfeller; Thomas Wörz; R. Schweikert; S. Lagrasta; R. Nicole?; G. Lo?pez-Risuen?o; D. Jime?nez-Ban?os

2010-01-01

69

Satellite systems for maritime navigation  

NASA Astrophysics Data System (ADS)

The principles underlying the design of Doppler satellite navigation systems are examined, and the characteristics of existing and proposed satellite systems for maritime navigation are described. Particular attention is given to the COSPAS-SARSAT system, GPS/Navstar, and the Navsat, Granas, and Geostar projects. The features of shipboard navigation instruments are examined.

Bogdanov, Valerii Anatol'evich; Sorochinskii, Valentin Alekseevich; Iakshevich, Evgenii Viktorovich

70

Satellite systems for maritime navigation  

Microsoft Academic Search

The principles underlying the design of Doppler satellite navigation systems are examined, and the characteristics of existing and proposed satellite systems for maritime navigation are described. Particular attention is given to the COSPAS-SARSAT system, GPS\\/Navstar, and the Navsat, Granas, and Geostar projects. The features of shipboard navigation instruments are examined.

Valerii Anatol'evich Bogdanov; Valentin Alekseevich Sorochinskii; Evgenii Viktorovich Iakshevich

1987-01-01

71

A Nonlinear Code Tracking Filter for GPS-Based Navigation  

Microsoft Academic Search

Current Global Positioning System (GPS)-based navigation systems are highly susceptible to unintentional and intentional jamming due to relatively low signal power at the receiver antenna and, in part, due to suboptimal code tracking loop designs that do not account for measurement nonlinearities near loss-of-lock. A nonlinear code tracking filter is developed whose architecture is based on a rigorous minimum-variance solution

Donald E. Gustafson; John R. Dowdle; John M. Elwell; Karl W. Flueckiger

2009-01-01

72

Integrated GPS\\/INS navigation system design for autonomous spacecraft rendezvous  

Microsoft Academic Search

The goal of the NASA Space Launch Initiative (SLI) program is to advance the technologies for the next generation reusable launch vehicle (RLV). The SLI program has identified automated rendezvous and docking as an area requiring further research and development. Currently, the Space Shuttle uses a partially manual system for rendezvous, but a fully automated system could be safer and

David Edward Gaylor

2003-01-01

73

INS\\/GPS integrated navigation for wheeled agricultural robot based on sigma-point Kalman Filter  

Microsoft Academic Search

This paper describes a numerical robust and computational efficient square-root central difference Kalman filter (SRCDKF) and put it into the application of state estimation of Inertial Navigation System (INS)\\/GPS integrated navigation for wheeled agricultural robot to overcome the flaws exist in EKF (Extended Kalman Filter). A standard INS mechanization with quaternion form attitude expression is introduced and a GPS antenna

Yuliang Zhang; Feng Gao; Lei Tian

2008-01-01

74

ICD-GPS-20OB-PR Navstar GPS Space Segment/Navigation User Interfaces (Public Release Version).  

National Technical Information Service (NTIS)

This Interface Control Document (ICD) defines the functional characteristics required to exist to assure compatibility between the Space Segment (SS) of the Global Positioning System and the Navigation User Segment (US) of the GPS. The exception is that t...

P. Fyfe K. Kovach

1991-01-01

75

A comparison of a mechanically stabilized gyrocompass and a GPS-aided inertial navigation system  

Microsoft Academic Search

The ability to sense ship's motion accurately is critical to the performance of Naval Oceanographic Office survey missions. Various instruments have been used over the years to provide survey mission equipment with information about ship's roll, pitch, heading, and vertical motion. Typically the cost and complexity of sensor systems used are directly proportional to the accuracy required. Advances have been

W. E. Bradley; F. van de Kop

1999-01-01

76

Global Navigation Satellite Systems: A Perspective on Reference Frame Evolution Over the Next Decade With GPS, GLONASS and Galileo  

NASA Astrophysics Data System (ADS)

The strategies of the IGS* to optimize the future use of multiple integrated GNSS - GPS and its modernization, the new Galileo, and GLONASS will be discussed. This is particularly important towards sustaining and evolving the precise reference frame maintained by the International Earth Rotation and Reference System's (IERS) International Terrestrial Reference Frame (ITRF). Since 1994, the IGS produces GPS data and products at the highest level of precision and accuracy available anywhere. IGS provides GPS orbits (3-5 cm wrms), sub-cm 3-D station positioning and velocities, and station and satellite clocks (sub-nanosecond) for users worldwide. A similar suite of data and products is available for GLONASS, demonstrating the ability of the IGS to incorporate observations from other GNSSs. IGS affirms interest to engage in the development and applications of the Galileo system and other GNSS. The authors will discuss IGS commitment to supporting the precise global reference frame and its densification through the GNSS techniques. A key objective of the IGS is to provide users anywhere in the world access to GNSS data, products and resources as a "global utility". This is naturally dependent upon the availability and performance of the various satellite systems. IGS currently consists of over 200 actively contributing organizations in more than 80 countries and a global network of 350+ stations. (*IGS is recently renamed as the International GNSS Service, formerly the International GPS Service).

Neilan, R. E.; Moore, A.; Dow, J.; Gendt, G.

2005-12-01

77

Introduction to Global Navigation Satellite System.  

National Technical Information Service (NTIS)

This viewgraph presentation reviews the fundamentals of satellite navigation, and specifically how GPS works. It presents an overview and status of Global Positioning System, for both the current GPS, and plans to modernize it in the future. There is also...

M. Moreau

2005-01-01

78

76 FR 39896 - In the Matter of Certain GPS Navigation Products, Components Thereof, and Related Software...  

Federal Register 2010, 2011, 2012, 2013

...337-TA-783] In the Matter of Certain GPS Navigation Products, Components Thereof...United States after importation of certain GPS navigation products, components thereof...United States after importation of certain GPS navigation products, components...

2011-07-07

79

GPS Global Positioning System  

Microsoft Academic Search

The NAVSTAR Global Positioning System (GPS) is described, including its current status, future plans, how it works, applications, and security\\/countermeasure aspects. Consideration is given to the space, control, and user segments of the GPS.

J. A. Austin

1980-01-01

80

Analyze and research the integrated navigation technique for GPS and pseudolite  

NASA Astrophysics Data System (ADS)

To heighten the stability and precision of GPS positioning, the integrated navigation system for GPS and pseudolites (GPS/PL) was set up. The nonlinear equation of pseudo-distance measurement was linearized by Taylor series expansion, but it can't find any influencing factors of the truncation error. A new deducing method of the linear equation of pseudo-distance measurement was put forward, and some influencing factors of the truncation error were found and the nonlinear degree was defined. By the comparison of the nonlinear degree for GPS and pseudolites, the truncation error of pseudolite was found much larger than that of GPS navigation during the linearization. In allusion to the stable flight state of aircrafts, the nonlinear system equations of an integrated navigation system for GPS and pseudolites (GPS/PL) were set up, and the unscented Kalman filter (UKF) was used to estimate the navigation parameters to solve the nonlinear problems of PL. The simulation results showed that the maximum positioning error is 14 meters, and the mean value is 7 meters. Thereby, the pseudolites make the enhancement for the positioning precision and system stability of GPS navigation.

Yuan, Gannan; Gan, Xingli; Li, Zhongyu

2007-11-01

81

Sensor data fusion for inertial navigation of trains in GPS-dark areas  

Microsoft Academic Search

The motivation of the presented work is to develop a robust navigation system for accurate localization of trains on railway tracks in the cases where the GPS-based navigation is not temporally available. As the final solution of the train locator naturally takes into consideration the satellite-based navigation, the satellite signal needs not to be available all along the railway. The

R. Mazl; L. Preucil

2003-01-01

82

Impact of GPS\\/Galileo Integration on Marine Navigation  

Microsoft Academic Search

Reliable and accurate positions are required for general marine navigation and specialized applications such as buoy tending. The GPS signals are often masked by obstructions, which results in degraded geometry and accuracy at best, and unavailable or unreliable positions at worst. Once Galileo is implemented by the European Union, the use of a combined GPS + Galileo receiver will result

S. Ryan; G. Lachapelle

83

Definition Study of Land/Sea Civil User Navigational Location Monitoring Systems for Navstar Gps: User Requirements and Systems Concepts.  

National Technical Information Service (NTIS)

A low-cost GPS civil-user mobile terminal whose purchase cost is substantially an order of magnitude less than estimates for the military counterpart is considered with focus on ground station requirements for position monitoring of civil users requiring ...

D. M. Devito

1981-01-01

84

The bird GPS - long-range navigation in migrants.  

PubMed

Nowadays few people consider finding their way in unfamiliar areas a problem as a GPS (Global Positioning System) combined with some simple map software can easily tell you how to get from A to B. Although this opportunity has only become available during the last decade, recent experiments show that long-distance migrating animals had already solved this problem. Even after displacement over thousands of kilometres to previously unknown areas, experienced but not first time migrant birds quickly adjust their course toward their destination, proving the existence of an experience-based GPS in these birds. Determining latitude is a relatively simple task, even for humans, whereas longitude poses much larger problems. Birds and other animals however have found a way to achieve this, although we do not yet know how. Possible ways of determining longitude includes using celestial cues in combination with an internal clock, geomagnetic cues such as magnetic intensity or perhaps even olfactory cues. Presently, there is not enough evidence to rule out any of these, and years of studying birds in a laboratory setting have yielded partly contradictory results. We suggest that a concerted effort, where the study of animals in a natural setting goes hand-in-hand with lab-based study, may be necessary to fully understand the mechanism underlying the long-distance navigation system of birds. As such, researchers must remain receptive to alternative interpretations and bear in mind that animal navigation may not necessarily be similar to the human system, and that we know from many years of investigation of long-distance navigation in birds that at least some birds do have a GPS - but we are uncertain how it works. PMID:19880719

Thorup, Kasper; Holland, Richard A

2009-11-01

85

Global Positioning System Tutorial: All About GPS  

NSDL National Science Digital Library

The Global Positioning System (GPS) is a very popular and useful tool, whether you're navigating on a long hike or just driving through an unfamiliar town. A good tutorial that introduces the basics of the technology is found on the Web site of a leading GPS company, Trimble. It starts by describing the underlying concepts of GPS and how it compares to other positioning systems. Then, the principle of satellite triangulation is explained with as little technical jargon as possible. A large section of the tutorial covers differential GPS, a developing technology with profound implications. Lastly, some applications that use GPS are mentioned, and a glossary clarifies a few special terms.

2007-03-06

86

Long-term evolution of navigation satellite orbits: GPS\\/GLONASS\\/GALILEO  

Microsoft Academic Search

A recent study was performed to examine whether long-term growth in the eccentricity evolution exists for the disposal orbits of navigation satellite systems such as GPS, GLONASS, and GALILEO. Previous studies examined the orbit stability for GPS Block II satellites. The orbits of the non-operational GPS Block I satellites are included in this study because they are at 63.4° inclination,

C. C. Chao; R. A Gick

2004-01-01

87

Navigation in GPS Challenged Environments Based Upon Ranging Imagery  

NASA Astrophysics Data System (ADS)

The ability of living creatures to navigate their environment is one of the great mysteries of life. Humans, even from an early age, can acquire data about their surroundings, determine whether objects are movable or fixed, and identify open space, separate static and non-static objects, and move towards another location with minimal effort, in infinitesimal time spans. Over extended time periods humans can recall the location of objects and duplicate navigation tasks based purely on relative positioning of landmarks. Our ability to emulate this complex process in autonomous vehicles remains incomplete, despite significant research efforts over the past half century. Autonomous vehicles rely on a variety of electronic sensors to acquire data about their environment; the challenge is to transform that data into information supporting the objective of navigation. Historically, much of the sensor data was limited to the two dimensional (2D) instance; recent technological developments such as Laser Ranging and 3D Sonar are extending data collection to full three dimensional (3D) acquisition. The objective of this dissertation is the development of an algorithm to support the transformation of 3D ranging data into a navigation solution within unknown environments, and in the presence of dynamically moving objects. The algorithm reflects one of the very first attempts to leverage the 3D ranging technology for the purpose of autonomous navigation, and provides a system which enables the ability to complete the following objectives: • Separation of static and non-static elements in the environment. • Navigation based upon the range measurements of static elements. This research extends the body of knowledge in three primary topics. 1) The first is the development of a general method to identify n features in an initial data set from m features in a subsequent data set, given that both data sets are acquired via 3D ranging sensors. Accomplishing this objective, particularly with respect to 2D datasets, has long been a difficult proposition when attempting to link overlapping data sets. 2) Secondly, an innovative methodology to segment a set of discrete 3D range measurements is presented. 3) Finally, the research develops a methodology to support navigation in environments previously infeasible for autonomous vehicles due to lack of position updates. This problem is well known in the navigation field; while Global Positioning Systems (GPS) provide excellent positional information, their signals can become unavailable in a wide variety of conditions. Current research in robotic manipulation rarely addresses the concept of operations within an unknown environment, and virtually never attempts navigation in the presence of non-static objects. The ability to extend the navigation solution beyond these limitations extends the possibilities for autonomous navigation and advances the field of navigation. The current algorithm cannot provide a navigation solution for an indefinite time period; it can extend the feasible extent of navigation without benefit of GPS positioning. While this research could not possibly claim to solve the problem of autonomous navigation, it represents an important step towards the vision of developing a machine to emulate cognitive navigation.

Markiel, J. N. Nikki

88

Space navigation systems and the role of clocks. The adopted solutions in the existing GPS system and in the planned Galileo system  

Microsoft Academic Search

This tutorial will present the general principles and nomenclature for orbits, space navigation, different types of navigation, and their requirements for electronic measurements. It will explore the role of the atomic clocks and time scales in global navigation. The tutorial will also give the important characteristics of the existing Global Positioning System and of the future GALILEO System, which will

Sigfrido Leschiutta; P. Tavella

2006-01-01

89

A high integrity IMU\\/GPS navigation loop for autonomous land vehicle applications  

Microsoft Academic Search

This paper describes the development and implementation of a high integrity navigation system, based on the combined use of the Global Positioning System (GPS) and an inertial measurement unit (IMU), for autonomous land vehicle applications. The paper focuses on the issue of achieving the integrity required of the navigation loop for use in autonomous systems. The paper highlights the detection

Salah Sukkarieh; Eduardo M. Nebot; Hugh F. Durrant-Whyte

1999-01-01

90

Designing a Remote Navigation System  

Microsoft Academic Search

This project involves the design and implementation of a global electronic tracking system intended for use by trans-oceanic vessels, using the technology of the U.S. Government's Global Positioning System (GPS) and a wireless connection to a networked computer.\\u000aTraditional navigation skills are being replaced with highly accurate electronics. GPS receivers, computers, and mobile communication are becoming common among both recreational

Jared P. Lazzaro

2000-01-01

91

Perspective\\/navigation-The Global Positioning System  

Microsoft Academic Search

A brief history of navigation is given, highlighting the needs that led ultimately to the development of 3-D satellite based navigation. The evolution of Navstar, commonly known as GPS (Global Positioning System), is traced from its initial conception in 1960. The use of bandwidth compression to overcome the SNR problem is discussed. An explanation of how the GPS works is

1993-01-01

92

NAVSTAR GPS (Global Positioning System) Simulation and Analysis Program.  

National Technical Information Service (NTIS)

The study assesses the capability of the planned NAVSTAR Global Positioning System (GPS) to meet civil navigation requirements. When it becomes operational in about 1988, NAVSTAR GPS will provide accurate two-dimensional and three-dimensional service to a...

R. Kalafus N. Knable J. Kraemer J. Vilcans

1983-01-01

93

A GPS\\/Shuttle orbital navigation experiment  

Microsoft Academic Search

A proposal is made to fly a Texas Instruments GPS geodetic receiver (GEOSTAR) on the Space Shuttle to evaluate its ability to perform autonomous orbit determination. GEOSTAR receiver and recorder units would be flown in the Shuttle's middeck for the purposes of computing real-time solutions and recording tracking data for post-flight analysis. Feasibility study results are presented which show that

G. Peters

1984-01-01

94

Optimising the Integration of Terrain Referenced Navigation with INS and GPS  

NASA Astrophysics Data System (ADS)

The benefits of integrated INS/GPS systems are well known. However, the knowledge required to jam GPS is becoming public and the hardware to achieve this is basic. When GPS data are unavailable and a low grade INS is used, navigation accuracy quickly degrades to an unacceptable level. The addition of one or more terrain referenced navigation (TRN) systems to an integrated INS/GPS navigation system enables the INS to be calibrated during GPS outages, increasing the robustness of the overall navigation solution. TRN techniques are compared and integration architectures are reviewed. For the initial studies of INS/GPS/TRN integration, radar altimeter based terrain contour navigation (TCN) with a batch processing algorithm is used in conjunction with a centralised integration filter. Four different approaches for using these TCN fixes to calibrate the INS are compared. These are a best fix method, a weighted fix method using a probabilistic data association filter (PDAF) and single and multi-hypothesis versions of the Iterative Gaussian Mixture Approximation of the Posterior (IGMAP) method. Simulation results are presented showing that the single hypothesis IGMAP technique offers the best balance between accuracy, robustness and processing efficiency.

Groves, Paul D.; Handley, Robin J.; Runnalls, Andrew R.

2006-01-01

95

Research on Navigation-Aids Information System  

Microsoft Academic Search

This thesis researches on the application of computer, modern communication, GIS, GPS, AIS and World-Wide-Web in the field of navigation-aids information system, and has realized an integrated system consisted of navigation-aids information GIS platform, navigation-aids monitoring system and navigation-aids information distribution system. This system has strong integration capability, and has realized navigation-aids information distribution based on WEBGIS at the first

Guojun Peng; Xinggu Zhang; Ran-xuan Ke; Jinxing Shao; Xin Chen

2008-01-01

96

GPS space navigation - A robust approach to withstand multiple satellite failures  

Microsoft Academic Search

This paper reports a preliminary investigation of the possibility of reducing the navigation performance sensitivity to extreme GPS outage conditions. The relevant system modeling and Kalman filter design characteristics are described, and analysis results are presented which show clear evidence that the inclusion of a few higher-order gravitational harmonics can significantly reduce the navigational performance degradation, as illustrated in a

Carlo Carnebianca

1989-01-01

97

Combining pseudoranges from GPS and Loran-C for air navigation  

NASA Astrophysics Data System (ADS)

The availability of services that could be provided by a combined GPS/Loran receiver is analyzed. Position fixing, receiver autonomous fault detection, and receiver autonomous fault isolation are treated as system services, and the probability of outage of these three services are calculated. The outage probability is assessed for the level of service required for nonprecision approach and en route navigation in the National Airspace System. It is assumed that GPS is configured in the Optimal 21 Satellite Constellation, and the effects of satellite as well as Loran station shutdowns are considered, along with Loran transmission synchronization to GPS time.

Enge, Per K.; Vicksell, Frona B.; Goddard, Robert B.; van Graas, Frank

98

High integrity GPS/INS filter for precise relative navigation  

NASA Astrophysics Data System (ADS)

A GPS/INS filter design for absolute and relative state estimation is discussed. The GPS code and Doppler measurements are used for absolute state estimation while the GPS carrier phase and Doppler measurements are used for relative state estimation. Real-time results obtained from a Hardware-in-the-Loop Simulation and actual F-18 flight tests are presented. To ensure accurate state estimation, the observability of the GPS/INS system is analyzed analytically when the system is at rest and during maneuvers. The system observability enhancement during two different maneuvers is discussed. Simulation results illustrating the observability of the system during the different stages of the GPS/INS system operation are also presented. To allow successful use of the high-accuracy carrier phase measurements, two methods for resolving GPS integer ambiguity are introduced. The first combines an efficient method for obtaining the admissible integer ambiguity hypotheses within a probabilistic volume with an integer hypothesis testing method to reduce the convergence time with high probability to the GPS carrier phase integers. The second GPS integer ambiguity resolution method is based on a log-formulation of the Multiple Hypothesis Wald Sequential Probability Test (MHWSPT). The computational time requirement of the latter method is shown to be smaller than the former method. Real-time results are presented to show the performance of the two methods introduced.

Abdel-Hafez, Mamoun F.

99

77 FR 16860 - Certain GPS Navigation Products, Components Thereof, and Related Software; Termination of...  

Federal Register 2010, 2011, 2012, 2013

...TRADE COMMISSION [Investigation No. 337-TA-783] Certain GPS Navigation Products, Components Thereof, and Related Software...and sale within the United States after importation of certain GPS navigation products, components thereof, and related...

2012-03-22

100

Navstar Global Positioning System (GPS): Future enhanced capabilities  

Microsoft Academic Search

Aspects of GPS research are reviewed. Navigation using radio interferometric techniques, analyses leading to more accurate orbit prediction of GPS satellites, and high precision application of GPS beyond the current 16 m spherical error probability capability are discussed. Improved ground systems are advocated in order to fully exploit the radio interferometric technique. User system signal processing and data processing capabilities

M. Ananda

1981-01-01

101

Combining pseudoranges from GPS and LoranC for air navigation  

Microsoft Academic Search

Position fixing, receiver autonomous fault detection, and receiver autonomous fault isolation are treated as system services, and the probability of outage for these three services is computed. The outage probability for the level of service required for nonprecision approach and enroute navigation in the National Airspace System is computed. The analysis assumes that GPS (Global Positioning System) is configured in

Per K. Enge; Frona B. Vicksell; Robert B. Goddard

1990-01-01

102

GPS-based relative navigation for the Proba-3 formation flying mission  

NASA Astrophysics Data System (ADS)

The primary objective of the Proba-3 mission is to build a solar coronagraph composed of two satellites flying in close formation on a high elliptical orbit and tightly controlled at apogee. Both spacecraft will embark a low-cost GPS receiver, originally designed for low-Earth orbits, to support the mission operations and planning during the perigee passage, when the GPS constellation is visible. The paper demonstrates the possibility of extending the utilization range of the GPS-based navigation system to serve as sensor for formation acquisition and coarse formation keeping. The results presented in the paper aim at achieving an unprecedented degree of realism using a high-fidelity simulation environment with hardware-in-the-loop capabilities. A modified version of the flight-proven PRISMA navigation system, composed of two single-frequency Phoenix GPS receivers and an advanced real-time onboard navigation filter, has been retained for this analysis. For several-day long simulations, the GPS receivers are replaced by software emulation to accelerate the simulation process. Special attention has been paid to the receiver link budget and to the selection of a proper attitude profile. Overall the paper demonstrates that, despite a limited GPS tracking time, the onboard navigation filter gets enough measurements to perform a relative orbit determination accurate at the centimeter level at perigee. Afterwards, the orbit prediction performance depends mainly on the quality of the onboard modeling of the differential solar radiation pressure acting on the satellites. When not taken into account, this perturbation is responsible for relative navigation errors at apogee up to 50 m. The errors can be reduced to only 10 m if the navigation filter is able to model this disturbance with 70% fidelity.

Ardaens, Jean-Sébastien; D'Amico, Simone; Cropp, Alexander

2013-10-01

103

It's a long way to Monte Carlo: probabilistic display in GPS navigation  

Microsoft Academic Search

We present a mobile, GPS-based multimodal navigation system, equipped with inertial control that allows users to explore and na- vigate through an augmented physical space, incorporating and displaying the uncertainty resulting from inaccurate sensing and unknown user intentions. The system propagates uncertainty ap- propriately via Monte Carlo sampling and predicts at a user- controllable time horizon. Control of the Monte

John Williamson; Steven Strachan; Roderick Murray-smith

2006-01-01

104

Vertical Component of Satellite Navigation Systems  

Microsoft Academic Search

The altitude is one of four coordinates of the user's position obtained from Satellite Navigation System (SNS) measurements. The distributions (in per cent) of VDOP coefficient value for different constellations of three SNS - GPS, GLONASS and Galileo - for different masking elevation angles for different user's latitudes are presented in the paper. The results of the measurements of GPS

Jacek Januszewski

2010-01-01

105

Land Vehicle Navigation with the Integration of GPS and Reduced INS: Performance Improvement with Velocity Aiding  

NASA Astrophysics Data System (ADS)

The movement of a land vehicle is constrained because the vehicle always remains on the Earth's surface and only experiences small pitch and roll angles. So the GPS/INS integrated system for land vehicle navigation could be reconfigured to be the integration of GPS and reduced INS to cut down the costs. In a reduced INS, the vertical accelerometer and two horizontal gyros could be omitted from the system. But both theoretical analysis and experimental results show that this configuration may result in the divergence of height solution and large velocity errors. To improve the system performances, precise velocity derived from GPS carrier phase measurements, together with the GPS single point positioning solution, is used to aid the reduced INS. Field test results have demonstrated that first, the aiding from GPS precise velocity overcomes the divergence problem of the integrated height solutions and improves the integrated velocity and secondly the proposed novel integration scheme could achieve comparable navigation accuracy with that from the GPS and full INS integrated system.

Han, Songlai; Wang, Jinling

106

Benefits of Combined GPS/GLONASS with Low-Cost MEMS IMUs for Vehicular Urban Navigation  

PubMed Central

The integration of Global Navigation Satellite Systems (GNSS) with Inertial Navigation Systems (INS) has been very actively researched for many years due to the complementary nature of the two systems. In particular, during the last few years the integration with micro-electromechanical system (MEMS) inertial measurement units (IMUs) has been investigated. In fact, recent advances in MEMS technology have made possible the development of a new generation of low cost inertial sensors characterized by small size and light weight, which represents an attractive option for mass-market applications such as vehicular and pedestrian navigation. However, whereas there has been much interest in the integration of GPS with a MEMS-based INS, few research studies have been conducted on expanding this application to the revitalized GLONASS system. This paper looks at the benefits of adding GLONASS to existing GPS/INS(MEMS) systems using loose and tight integration strategies. The relative benefits of various constraints are also assessed. Results show that when satellite visibility is poor (approximately 50% solution availability) the benefits of GLONASS are only seen with tight integration algorithms. For more benign environments, a loosely coupled GPS/GLONASS/INS system offers performance comparable to that of a tightly coupled GPS/INS system, but with reduced complexity and development time.

Angrisano, Antonio; Petovello, Mark; Pugliano, Giovanni

2012-01-01

107

Vertical Component of Satellite Navigation Systems  

NASA Astrophysics Data System (ADS)

The altitude is one of four coordinates of the user's position obtained from Satellite Navigation System (SNS) measurements. The distributions (in per cent) of VDOP coefficient value for different constellations of three SNS - GPS, GLONASS and Galileo - for different masking elevation angles for different user's latitudes are presented in the paper. The results of the measurements of GPS position and vertical accuracy in mode "3D" and position accuracy in mode "2D" for different GPS receivers and different receiver's antenna heights are demonstrated also. Additionally the use of vertical component of SNS in maritime navigation like the determination highly accurate sea-floor depths is presented.

Januszewski, Jacek

2010-01-01

108

Navigation and Attitude Estimation from GPS Pseudorange, Carrier Phase and dopples Observables  

NASA Astrophysics Data System (ADS)

This paper describes a procedure for navigation solution and attitude determination based on GPS observables only. The algorithm is supposed to be a contribution to the INPE's development project of a GPS receiver and antennas for space applications. Usually, the subjects of GPS-based navigation solution and attitude determination have been addressed separately. Several algorithms have been presented for navigation fix, velocity determination, orbit determination and attitude determination. In some cases the algorithms are based on the pseudoranges alone while in other cases the Doppler is used or the carrier phase. Also, there are a number of algorithms integrating inertial sensors with GPS in order to improve the dynamical model, especially in applications where GPS signal outages are likely to happen. The proposed procedure estimates the satellite position, velocity, attitude and angular rate from all pseudorange C/A, carrier phase L1 and Doppler D1 observables from multiple antennas. One considers a class of applications including, but not restricted to, Earth stabilized LEO satellites. In this case, the visibility condition is stable and allows continuous locking of several GPS satellites simultaneously, even in polar latitudes. Furthermore, the dynamics of a three-axis stabilized satellite is quite smooth. One takes advantage from the redundant information on the GPS observables to eliminate the need of inertial sensors or any sophisticate dynamical model, by means of dynamic compensation of non-modeled accelerations. Local, least squares estimates from the GPS observables are taken as state observations for a Kalman filter. Both observation errors and dynamic noise are modeled as locally stationary, first order Markovian processes with correlation time constant and noise intensity empirically adjusted by a technique based on the mean time between signal inversions. The algorithm was tested with simulated data and the Kalman filter converged to a steady-state accuracy level considerably better than the one given by the local estimates. Preliminary results using real data taken from a ground experiment with a Beeline GPS receiver indicates that the algorithm is promising and should be considered for use in the integrated navigation and attitude system by GPS being currently developed at INPE.

Vieira, D.

109

GpsTunes: controlling navigation via audio feedback  

Microsoft Academic Search

We combine the functionality of a mobile Global Positioning System (GPS) with that of an MP3 player, implemented on a PocketPC, to produce a handheld system capable of guiding a user to their desired target location via continuously adapted music feedback. We illustrate how the approach to presentation of the audio display can benefit from insights from control theory, such

Steven Strachan; Parisa Eslambolchilar; Roderick Murray-Smith; Stephen Hughes; Sile O'Modhrain

2005-01-01

110

Navigation and slope detection system design for autonomous mobile robot  

Microsoft Academic Search

Autonomous mobile robot navigation is a hot research field in recent years. We design a four-tracked autonomous mobile robot with a main-controller based on ARM s3c2410 and sub-controller based on ATmega128. The navigation system consists of GPS, INS, ultrasonic and infrared sensors. The used of the GPS and inertial navigation system for autonomous mobile robot makes its navigation precision and

Boyu Wei; Junyao Gao; Kejie Li; Hu Chen

2009-01-01

111

Development of a Frequency Dependent INS/GPS System Response Model for Bridging GPS Outages  

NASA Astrophysics Data System (ADS)

The integration of Inertial Navigation System (INS) and Global Positioning System (GPS) architectures can be achieved through the use of many time domain filters such as, an extended Kalman filter, an unscented Kalman filter, divided difference filter, and particle filter. The main objective of all the above filters is to achieve precise fusion of the data from GPS and INS to provide INS only navigation solution during GPS outages. The prediction mode performance of all state of the art time domain filters is poor with significant drift in the INS only solution. In this paper, a new frequency domain dynamic response method with variable frequency bandwidth is proposed to model the INS/GPS system. The Least Squares Spectral Analysis (LSSA), Parzen window based smoothing, and the Inverse Least Squares Fourier Transform (ILSFT) are employed to develop the INS/GPS system frequency response (transfer function). The input to this dynamic system is the INS only solution and the output is the INS/GPS integration solution. The discrete inverse ILSFT of the transfer function is applied to estimate the impulse response of the INS/GPS system. The focus of this paper is the improvement in velocity solution, which leads to almost the same level of improvement in the position solution in an INS/GPS system. To examine the performance of the proposed approach, a kinematic dataset (Dual frequency GPS data from a Trimble BD950 receiver and inertial data from DQI100 IMU) is collected in Hamilton Harbour, Ontario, onboard a hydrographic surveying vessel owned by the Canadian Hydrographic Service. The loosely coupled INS/GPS with unscented Kalman filter is developed to obtain an INS/GPS integrated navigation solution and an INS only solution. Then, the INS/GPS and INS only navigation solutions are used to develop the impulse response of the INS/GPS system. It is shown that the developed impulse response can be used to detect and recover the long term motion dynamics of DQI100 IMU during 300s GPS outages with about 65% dynamic recovery of the north velocity and 45% dynamic recovery of east velocity solution when compared with the INS only solution. We will present and discuss many examples from a variety of GPS outages that exemplify the effectiveness of our method.

El-Diasty, M.; Pagiatakis, S.

2009-05-01

112

An intelligent and autonomous MEMS IMU\\/GPS integration scheme for low cost land navigation applications  

Microsoft Academic Search

An intelligent scheme to integrate inertial navigation system\\/global positioning system (GPS) is proposed using a constructive\\u000a neural network (CNN) to overcome the limitations of current schemes, namely Kalman filtering (KF). The proposed CNN technique\\u000a does not require prior knowledge or empirical trials to implement the proposed architecture since it is able to construct\\u000a its architecture “on the fly,” based on

Yun-Wen Huang; Kai-Wei Chiang

2008-01-01

113

Global Positioning Systems (GPS)  

NSDL National Science Digital Library

View an animated Flash slide show explaining how GPS works. GPS operates because of three interconnected segments: the satellite, ground control, and user segments. This animation focuses on the satellite and user segments, briefly touching upon how the satellite signal is processed to produce positional values in hand-held GPS units. Note that the accuracy claimed for handheld GPS units 100 m is now routinely exceeded. With the turning off of selective availability, today's GPS handheld units usually get accuracies of better than 10 meters. Note that the video loads slowly.

Wiley

114

Real-time navigation using the global positioning system  

Microsoft Academic Search

This paper presents the results of an investigation of the application of the Global Positioning System (GPS) to real-time integrated missile navigation. We present quantifiable measures of navigation accuracy as a function of GPS user segment parameters. These user segment parameters include antenna phase response accuracy, single versus dual frequency, and Kalman filter structure and size. We also formulate some

Dan Simon; Hossny El-Sherief

1995-01-01

115

GPS navigation processing using the quaternion-based divided difference filter  

Microsoft Academic Search

Divided difference filter (DDF) with quaternion-based dynamic process modeling is applied to global positioning system (GPS)\\u000a navigation. Using techniques similar to those of the unscented Kalman filter (UKF), the DDF uses divided difference approximations\\u000a of derivatives based on Stirling’s interpolation formula which results in a similar mean but different posterior covariance\\u000a compared to the extended Kalman filter (EKF) solutions. The

Dah-Jing Jwo; Mei-Ying Hsieh; Shih-Yao Lai

2010-01-01

116

Analysis of GPS and Loran-C performance for land vehicle navigation in the Canadian Rockies  

NASA Astrophysics Data System (ADS)

Loran-C and GPS (Global Positioning System) were assessed for vehicular navigation along selected roads of British Columbia during the winter of 1991. The general topography of this mountainous area is described, together with the specific topographic features and tree coverage characteristics of the 2000 km of roads tested on the mainland and on Vancouver Isalnd. The configuration and characteristics of the Loran-C Canadian West Coast chain along the roads used are described. The portable vehicle-mounted LORCAL2 (Loran Calibration at the University of Calgary) system used to collect and analyze the Loran-C and GPS signals along road profiles is described. The performance of Loran-C is analyzed in terms of signal to noise ratios, field strength, and time difference distortions, as measured by differential GPS. These distortions, which can reach several hundred meters over distances of less than 20 km, are analyzed in terms of topographic features. The possibility of using these time-independent distortions to calibrate Loran-C for use along the above roads is discussed. Masking of GPS signals due to topographic features and tree coverage along the roads is analyzed. A comparative analysis of Loran-C and GPS is presented in terms of signal availability and accuracy.

Lachapelle, G.; Townsend, B.; Halayko, David

117

Navigation with IMU\\/GPS\\/digital compass with unscented Kalman filter  

Microsoft Academic Search

Autonomous vehicle navigation with standard IMU and differential GPS has been widely used for aviation and military applications. Our research interesting is focused on using some low-cost off-the-shelf sensors, such as strap-down IMU, inexpensive single GPS receiver. In this paper, we present an autonomous vehicle navigation method by integrating the measurements of IMU, GPS, and digital compass. Two steps are

Pifu Zhang; Jason Gu; Evangelos E. Milios; Peter Huynh

2005-01-01

118

Non-GPS navigation utilizing randomly distributed sensor networks  

NASA Astrophysics Data System (ADS)

The emergence of affordable practical miniature sensors has led to a tremendous leap forward in the ability to conduct effective Intelligence, Surveillance, and Reconnaissance (ISR) on the modern battlefield. Sensors are now impressively small and are capable of sensitively sensing many phenomena. Coupling this sensor data with a real world coordinate often provides the best tactical picture. However, it is not always practical to outfit these sensors with Global Positioning System (GPS) receivers because of size, weight and power (SWAP) limitations. It is very conceivable that hundreds or thousands of these sensors could be randomly distributed over a region, precluding careful placement at specified locations. In this paper, we propose a method for not only locating the individual sensors, but also subsequently using the resulting sensor network as an alterative to GPS.

Dryer, Jay E.

2003-08-01

119

Synergistic Navigation System Study.  

National Technical Information Service (NTIS)

Phase I of the Synergistic Navigation Systems Study is a comparison analysis of the cost/effectiveness of various optimal filtering techniques for a Doppler-inertial navigation system with position-fixing. The costs are assessed in terms of program execut...

K. A. Klementis C. J. Standish

1966-01-01

120

GPS inferred geocentric reference frame for satellite positioning and navigation  

NASA Astrophysics Data System (ADS)

Accurate geocentric three-dimensional positioning is of great importance for various geodetic and oceanographic applications. While relative positioning accuracy of a few centimeters has become a reality using Very Long Baseline Interferometry (VLBI), the uncertainty in the offset of the adopted coordinate system origin from the geocenter is still believed to be of the order of one meter. Satellite Laser Ranging (SLR) is capable of determining this offset to better than 10 cm, though, because of the limited number of satellites, this requires a long arc of data. The Global Positioning System (GPS) measurements provide a powerful alternative for an accurate determination of this origin offset in relatively short period of time. Two strategies are discussed, the first utilizes the precise relative positions predetermined by VLBI, whereas the second establishes a reference frame by holding only one of the tracking sites longitude fixed. Covariance analysis studies indicate that geocentric positioning to an accuracy of a few centimeters can be achieved with just one day of precise GPS pseudorange and carrier phase data.

Malla, Rajendra P.; Wu, Sien-Chong

121

Tightly coupled low cost 3D RISS/GPS integration using a mixture particle filter for vehicular navigation.  

PubMed

Satellite navigation systems such as the global positioning system (GPS) are currently the most common technique used for land vehicle positioning. However, in GPS-denied environments, there is an interruption in the positioning information. Low-cost micro-electro mechanical system (MEMS)-based inertial sensors can be integrated with GPS and enhance the performance in denied GPS environments. The traditional technique for this integration problem is Kalman filtering (KF). Due to the inherent errors of low-cost MEMS inertial sensors and their large stochastic drifts, KF, with its linearized models, has limited capabilities in providing accurate positioning. Particle filtering (PF) was recently suggested as a nonlinear filtering technique to accommodate for arbitrary inertial sensor characteristics, motion dynamics and noise distributions. An enhanced version of PF called the Mixture PF is utilized in this study to perform tightly coupled integration of a three dimensional (3D) reduced inertial sensors system (RISS) with GPS. In this work, the RISS consists of one single-axis gyroscope and a two-axis accelerometer used together with the vehicle's odometer to obtain 3D navigation states. These sensors are then integrated with GPS in a tightly coupled scheme. In loosely-coupled integration, at least four satellites are needed to provide acceptable GPS position and velocity updates for the integration filter. The advantage of the tightly-coupled integration is that it can provide GPS measurement update(s) even when the number of visible satellites is three or lower, thereby improving the operation of the navigation system in environments with partial blockages by providing continuous aiding to the inertial sensors even during limited GPS satellite availability. To effectively exploit the capabilities of PF, advanced modeling for the stochastic drift of the vertically aligned gyroscope is used. In order to benefit from measurement updates for such drift, which are loosely-coupled updates, a hybrid loosely/tightly coupled solution is proposed. This solution is suitable for downtown environments because of the long natural outages or degradation of GPS. The performance of the proposed 3D Navigation solution using Mixture PF for 3D RISS/GPS integration is examined by road test trajectories in a land vehicle and compared to the KF counterpart. PMID:22163846

Georgy, Jacques; Noureldin, Aboelmagd

2011-04-08

122

Inertial Navigational Systems.  

National Technical Information Service (NTIS)

A semi-technical discussion is given of operating conditions, interaction of separate units and causes of errors of inertial guidance and navigational systems. Considerable attention is given to analysis of the operation of inertial systems under conditio...

V. S. Frolov

1964-01-01

123

Satellite-aided navigation - Availability and application of the Global Positioning System  

Microsoft Academic Search

Many experts expect that the U.S. Global Positioning System (GPS) will become the principal navigational system of the future and will replace most of the currently existing navigational systems. Such a development will provide a market for a variety of GPS-user devices. The GPS-Navstar system will probably become fully available to users in 1987\\/88. Applications of the GPS are discussed,

H. Dodel; A. Stiller

1985-01-01

124

SystemC Model of an Interoperative GPS\\/Galileo Code Correlator Channel  

Microsoft Academic Search

Global navigational satellite systems (GNSS) are on the threshold of a new era. American global positioning system (GPS) gets a new rival from Europe as Galileo system is developing rapidly. For the best availability and navigation performance, users should be able to use satellites from both systems. There are two common operational frequency bands between GPS and Galileo, L1\\/E1 and

Heikki Hurskainen; Jari Nurmi

2006-01-01

125

Autonomous satellite navigation methods using the Global Positioning Satellite System  

Microsoft Academic Search

This investigation considers the problem of autonomous satellite navigation using the NAVSTAR Global Positioning System (GPS). The major topics covered include the design, implementation, and validation of onboard navigation filter algorithms by means of computer simulations. The primary errors that the navigation filter design must minimize are computational effects and modeling inaccuracies due to limited capability of the onboard computer.

M. Murata; B. D. Tapley; B. E. Schutz

1982-01-01

126

New experimental results on GPS\\/INS navigation for Ocean Voyager II AUV  

Microsoft Academic Search

This paper presents preliminary experimental results on small-sized autonomous underwater vehicle navigation in shallow water environments. The vehicle was chosen to be our second-generation Ocean Voyager II which has been integrated with on-board GPS\\/INS sensors. These first-cut results reveal practical problems when using raw GPS fixes to perform high-precision real-time navigation. Among these, the most damaging factor is the observed

P. E. An; A. J. Healey; S. M. Smith; S. E. Dunn

1996-01-01

127

Introducing relativity in global navigation satellite systems  

NASA Astrophysics Data System (ADS)

Today, the Global Navigation Satellite Systems, used as global positioning systems, are the GPS and the GLONASS. They are based on a Newtonian model and hence they are only operative when several relativistic effects are taken into account. The most important relativistic effects (to order 1/c(2) ) are: the Einstein gravitational blue shift effect of the satellite clock frequency (Equivalence Principle of General Relativity) and the Doppler red shift of second order, due to the motion of the satellite (Special Relativity). On the other hand, in a few years the Galileo system will be built, copying the GPS system unless an alternative project is designed. In this work, it will be also shown that the SYPOR project, using fully relativistic concepts, is an alternative to a mere copy of the GPS system. According to this project, the Galileo system would be exact and there would be no need for relativistic corrections.

Pascual-Sánchez, J.-F.

2007-04-01

128

GPS INS Vehicle Attitude System.  

National Technical Information Service (NTIS)

Systems are provided to increase the robustness of a low-cost GPS system by coupling it with an INS system, and by using one-satellite attitude determination in conjunction with the traditional multiple-satellite method. The system has demonstrated accura...

J. D. Powell S. Alban S. M. Rock

2004-01-01

129

Design of GPS Remote Calibration System  

Microsoft Academic Search

A new design of GPS remote time and frequency calibration system is presented. Its hardware was composed with a time interval counter card, a GPS receiving modular and a controller. The counter card was manufactured with modeled number GT200 by Guide Technology, Inc. The Trimble ThunderBolt GPS disciplined clock was used as the GPS receiving modular. A personal computer with

Chia-Shu Liao; Hsin-Min Peng; Huang-Tien Lin; Shinn-Yan Lin; Kun-Yuan Tu; Han Shyu

2007-01-01

130

Political and economic dimensions of Global Navigation Satellite System (GNSS)  

Microsoft Academic Search

The evolution of the Global Positioning System (GPS) and Global Navigation Satellite Service (GLONASS) and the rise of Galileo may not be just a triumph of space based technology but in many cases may be a direct consequence of the national policies intended to promote political and economic interests. This can be argued by looking at the success of GPS

M. S. Khan

2001-01-01

131

The global positioning system, relativity, and extraterrestrial navigation  

Microsoft Academic Search

Relativistic effects play an important role in the performance of the Global Positioning System (GPS) and in world-wide time comparisons. The GPS has provided a model for algorithms that take relativistic effects into account. In the future exploration of space, analogous considerations will be necessary for the dissemination of time and for navigation. We discuss relativistic effects that are important

Neil Ashby; Robert A. Nelson

2010-01-01

132

Autonomous Orbit Navigator Development, Using GPS, Applied to Autonomous Orbit Control  

NASA Astrophysics Data System (ADS)

The appearance of modem global positioning systems motivated the study and development of precise and robust systems for autonomous orbit determination of artificial satellites. These systems maintain, independently from human intervention from the ground, a precise knowledge of the satellite orbital state, through the processing of the information, autonomously generated on-board, by a receiver of the positioning system used. One of the major motivations for the research and development of autonomous navigators, is the availability of real time information about the position and velocity of the satellite, required, for instance, in earth observation missions, for interpretation and analysis of the generated images. The appearance of global positioning systems and the consequent development of autonomous navigators, by making available onboard space vehicles, updated orbit estimations, with good accuracy level, made feasible the research and development of orbit autonomous control procedures. It allowed the orbital maneuvers execution process to be performed in a way totally independent from ground human intervention. Whereas the satellite attitude control reached a high level of autonomy, due to the fact that the attitude measurements are, in general, naturally generated on-board the spacecraft, the orbit control is still now almost totally planned and executed from ground commanded actions. The proposed work consists of the study, development, simulation and analysis of a simplified navigator coupled to an autonomous orbit control system, applied to the China-Brazil Earth Resources Satellites (CBERS). At first, an autonomous orbit determination procedure is developed and analyzed. Its objective is to improve the coarse geometric solution provided by Global Positioning System (GPS) receivers. This will be done by directly using this solution as input (observation) for a real time Kalman filtering process. The orbital state vector will be extended in order to include the systematic error imposed to the GPS geometric solution due to changes in the set of satellites which are visible to the receiver. The improved outputs of this process will then be used in the implementation of an autonomous control system for the Longitude Phase Drift of the spacecraft orbit (parameter which presents the higher frequency of corrective maneuvers application for heliosynchronous orbits in phase with the earth's rotation, as is the case for the CBERS series satellites. Finally, the performance of the proposed autonomous control procedure will be analyzed and compared with the other results achieved by autonomous control systems previously studied at Instituto Nacional de Pesquisas Espaciais (INPE), that directly use the coarse GPS navigation solution

Galski, Roberto Luiz

2002-01-01

133

Design and implementation of small navigation system on land vehicle  

NASA Astrophysics Data System (ADS)

This paper is focused on the problem of frame loss and truncation on multi-channel universal asynchronous receiver transmitter (UART) embedded in Integrated Navigation Systems, and it contains attitude heading reference system (AHRS) and global positioning system (GPS). An advanced design based on FPGA and ARM processor is discussed in this paper, in which FPGA would be used to coordinate with each logic modules, expand UART for GPS and AHRS, resolve navigation information, and save specify data to SD card, which can reduce the delay in data receiving and resolving, while ARM is applied in the area of parameters estimation and navigation algorithms. The experiment results show that this navigation system can use UART to receive, resolve data frames and save data while ARM execute parameter estimation and navigation algorithms in real time. This integrated navigation can effectively avoid the phenomenon of data frame loss or truncation in UART receiving, and can improve the navigation precision.

Ma, Shuaiqi

2013-03-01

134

Alternatives to GPS  

Microsoft Academic Search

The U.S. Navy is currently pursuing several approaches to improving the reliability of precision navigation systems, including those that would still permit precision navigation in the event that the Global Positioning System (GPS) is denied or unavailable. This paper examines two alternatives to GPS: bathymetric and celestial navigation. Bathymetric navigation, a non-deniable source of position, determines a position by correlating

F. Pappalardi; S. J. Dunham; M. E. LeBlang; T. E. Jones; J. Bangert; G. Kaplan

2001-01-01

135

Geostar - Navigation location system  

NASA Astrophysics Data System (ADS)

The author describes the Radiodetermination Satellite Service (RDSS). The initial phase of the RDSS provides for a unique service enabling central offices and headquarters to obtain position-location information and receive short digital messages from mobile user terminals throughout the contiguous United States, southern Canada, and northern Mexico. The system employs a spread-spectrum, CDMA modulation technique allowing multiple customers to use the system simultaneously, without preassigned coordination with fellow users. Position location is currently determined by employing an existing radio determination receiver, such as Loran-C, GPS, or Transit, in the mobile user terminal. In the early 1990s position location will be determined at a central earth station by time-differential ranging of the user terminals via two or more geostationary satellites. A brief overview of the RDSS system architecture is presented with emphasis on the user terminal and its diverse applications.

Keyser, Donald A.

136

Mitigating tropospheric propagation delay errors in precise airborne GPS navigation  

Microsoft Academic Search

The high spatial and temporal variability of the troposphere is well known, as is its effect-through propagation delays-on GPS positioning. This effect can be particularly problematical in airborne kinematic differential positioning where the altitude difference between reference station and aircraft is typically quite large. The use of zenith delay models and mapping functions at ground stations is fairly well understood,

J. P. Collins; R. B. Langley

1996-01-01

137

High accuracy integrated global positioning system/inertial navigation system LDRD: Final report  

SciTech Connect

This report contains the results of a Sandia National Laboratories Directed Research and Development (LDRD) program to investigate the integration of Global Positioning System (GPS) and inertial navigation system (INS) technologies toward the goal of optimizing the navigational accuracy of the combined GPSANS system. The approach undertaken is to integrate the data from an INS, which has long term drifts, but excellent short term accuracy, with GPS carrier phase signal information, which is accurate to the sub-centimeter level, but requires continuous tracking of the GPS signals. The goal is to maintain a sub-meter accurate navigation solution while the vehicle is in motion by using the GPS measurements to estimate the INS navigation errors and then using the refined INS data to aid the GPS carrier phase cycle slip detection and correction and bridge dropouts in the GPS data. The work was expanded to look at GPS-based attitude determination, using multiple GPS receivers and antennas on a single platform, as a possible navigation aid. Efforts included not only the development of data processing algorithms and software, but also the collection and analysis of GPS and INS flight data aboard a Twin Otter aircraft. Finally, the application of improved navigation system accuracy to synthetic aperture radar (SAR) target location is examined.

Owen, T.E.; Meindl, M.A.; Fellerhoff, J.R.

1997-03-01

138

An advanced system for performance evaluation of integrated navigation systems  

Microsoft Academic Search

• A test system designed for field performance evaluation of integrated aircraft navigation systems was described. It is based on off-line data processing and analysis of inertial sensors' measurements and carrier phase differential GPS data from multiple antennas • First experimental tests were carried out on ground using a partial version of the test setup. Results are promising: • Off

Giancarmine Fasano; Alfredo Renga; Domenico Accardo; Michele Grassi; Roberto Senatore

2011-01-01

139

Supply Chain Basics: Tracking Trucks with GPS (Global Positioning System).  

National Technical Information Service (NTIS)

The Global Positioning System (GPS) is a radio navigation system that uses information from satellites to calculate the position of an object on Earth. Its use has widened recently as the cost of the technology has decreased. It is an essential management...

G. Berney

2008-01-01

140

Flight evaluation of GPS precise point positioning for helicopter navigation  

Microsoft Academic Search

We reported development and assessment of a precise point positioning (PPP) software for land vehicular navigation in 2006. This paper presents one phase of the continued study at NDA for further extension of the software to helicopter navigation. For 3D users, the height-dependent tropospheric delay is a critical factor, and so the sophisticated correction models and parameter estimation strategies have

Yutaka Shimizu; Masaaki Murata

2007-01-01

141

Satellite-aided navigation - Availability and application of the Global Positioning System  

NASA Astrophysics Data System (ADS)

Many experts expect that the U.S. Global Positioning System (GPS) will become the principal navigational system of the future and will replace most of the currently existing navigational systems. Such a development will provide a market for a variety of GPS-user devices. The GPS-Navstar system will probably become fully available to users in 1987/88. Applications of the GPS are discussed, taking into account navigation and positioning applications on land in cases involving motor vehicles and trains, navigation and position determination related to Space-Shuttle operations and docking activities in near-earth space, maritime applications, and possibilities for time comparison and clock synchronization. The development of GPS receivers in West Germany is also considered, giving attention to user equipment for a comparison of clocks and for time transfer operations, position-finding apparatus for geodesy and land surveys, navigation devices for civil aviation, and navigation systems for ships.

Dodel, H.; Stiller, A.

142

A simple visual navigation system for an UAV  

Microsoft Academic Search

We present a simple and robust monocular camera-based navigation system for an autonomous quadcopter. The method does not require any additional infrastructure like radio beacons, artificial landmarks or GPS and can be easily combined with other navigation methods and algorithms. Its computational complexity is independent of the environment size and it works even when sensing only one landmark at a

Tomas Krajnik; Matias Nitsche; Sol Pedre; Libor Preucil; Marta E. Mejail

2012-01-01

143

GPS\\/INS Integration in Real-time and Post processing with NovAtel's SPAN System  

Microsoft Academic Search

NovAtel offers a GPS\\/INS solution with a uniquely robust architecture. The SPAN (Synchronized Position Attitude Navigation) system builds on the OEMV receiver, by integrating inertial measurements to provide a high-rate, continuous navigation solution. The integration is tightly coupled with access to the GPS receiver core, with both the GPS and inertial processing benefiting from the integration. Typically, GPS measurements are

Sandy Kennedy; Darren Cosandier

2007-01-01

144

Plans of the U.S. Government for the future radio navigation services Navstar GPS and consequences for the precise positioning and navigation at sea  

NASA Astrophysics Data System (ADS)

The developments considered in the present paper are of interest to a group of users who require accurate positioning and navigation data at sea and in areas in the vicinity of harbors. Such data are needed for hydrographic sea surveying activities, oceanography, seismic measurements, applications related to fishing, and the positioning of offshore platforms for oil-drilling operations. The requirements include demands for an absolute accuracy in the range from 5 to 15 meters. A source of information concerning the plans of the U.S. Government regarding its radio navigation services is provided by the 'Federal Radionavigation Plan' (FRP). Attention is given to the policies of the U.S. Government regarding the Global Positioning System (GPS), the utilization of the Precise Positioning Service by civil users, plans with respect to existing radio navigation services, details regarding navigational requirements, and cost considerations.

Rehmert, H.

145

GPS instrumentation for the Trident weapon system  

NASA Astrophysics Data System (ADS)

With the planned full operational deployment of the Navstar Global Positioning System (GPS), many applications for the system are beginning to be developed. This paper discusses the concept of GPS instrumentation for the Trident II (D-5) program as well as the background for the Navy's use of existing GPS assets for test evaluation of the Trident I (C-4) Weapon System. Included are the concepts of translated GPS used for real-time tracking for missile range safety as well as for posttest performance evaluation (metric tracking) of the Trident guidance system. The use of GPS pseudosatellite signals to enhance the robustness of the tracking system to provide range safety information is presented. GPS time transfer capabilities are to be used to ensure efficient time synchronization operation for all stations. The unique design features associated with using GPS for range instrumentation are highlighted.

Grossman, J.; Jacobson, L.; Wells, L.

146

Analysis on the One-Way Communication Capability of GPS Satellites in Orbit Transmitting Non-navigational Information  

Microsoft Academic Search

The GPS system is capable of the one-way communication (OWC) transmitting non-navigational information if the reserved bits of L1C Nav message and the newly-added CNav message types for L2C signal are utilized. Excluding the potential communication protocol overheads, a single frequency with one satellite transmits data at 0.5B\\/s; with the dual frequency transmission by using L1C and L2C frequencies and

Cheng Xi-jun; Xu Jiang-ning; Cao Ke-jin; Zhu Ying-bin

2009-01-01

147

Civil satellite navigation systems  

NASA Astrophysics Data System (ADS)

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

Blanchard, Walter F.

1991-07-01

148

GPS-Based Navigation and Orbit Determination for the AMSAT Phase 3D Satellite.  

National Technical Information Service (NTIS)

This paper summarizes the results of processing GPS data from the AMSAT Phase 3D (AP3) satellite for real-time navigation and post-processed orbit determination experiments. AP3 was launched into a geostationary transfer orbit (GTO) on November 16, 2000 f...

G. Davis R. Carpenter M. Moreau F. H. Bauer A. Long D. Kelbel T. Martin

2002-01-01

149

Inertie-GPS (Global Positioning System): Un Mariage de Raison - a l'Essai (Inertial-Gps: A Marriage of Reason, an Analysis).  

National Technical Information Service (NTIS)

The coupling of inertial navigation methods with the Global Positioning System (GPS) is examined. The characteristics of various types of inertial systems are reviewed and past attempts at inertial/radionavigation hybridizations including those with multi...

P. Lloret B. Capit

1986-01-01

150

Ubiquitous GPS vehicle tracking and management system  

Microsoft Academic Search

Global Positioning System (GPS) is becoming widely used for tracking and monitoring vehicles. Many systems have been created to provide such services which make them popular and needed more than ever before. In this paper a “GPS vehicle tracking system” is proposed. This system is useful for fleet operators in monitoring driving behavior of employees or parents monitoring their teen

Iman M. Almomani; Nour Y. Alkhalil; Enas M. Ahmad; Rania M. Jodeh

2011-01-01

151

Design and Performance Analysis of GPS Based Precise Relative Navigation for Rendezvous and Formation Flying Missions in Low Earth Orbit  

NASA Astrophysics Data System (ADS)

Precise relative GPS navigation is essential technology for rendezvous and formation flying of spacecraft in Low Earth Orbit. Key design issues of precise relative GPS navigation software are studied and a novel formulation is proposed for the mission which requires high accuracy when the separation distance is up to several km. The navigation filter estimates float navigation solutions by extended Kalman filter with elaborate dynamics models, and resolves ambiguities of integer carrier phase biases to achieve high accuracy fix navigation solutions. A relative navigation software with the proposed formulation is implemented and evaluated in two different ways. One is a test using spacebourne GPS receivers and a GPS signal simulator to evaluate the performance and sensitivity of the software against variation of parameters. The other is a test using actual telemetry data from Gravity Recovery and Climate Experiment (GRACE) to demonstrate the software performance. The design, implementation, and results of the evaluation are presented and discussed on this paper.

Yamamoto, Toru

152

Space-qualified GPS receiver and MIMU for an autonomous on-board guidance and navigation package  

NASA Astrophysics Data System (ADS)

The interest for an integrated autonomous guidance and navigation control package, satisfying to different mission requirements with a common architecture, is becoming very attractive in the perspective to reduce cost mission and to provide significant benefits when measurements noise conditions may change during the mission and safety critical spacecraft operations are involved. In this paper Laben and Honeywell present an interesting approach to integrate an attitude GPS space receiver and a miniaturized inertial measurement unit (MIMU), to enhance the performances of both sensor systems. In traditional G&NC systems, based on Inertial Navigation Sensor (INS) Measurements, long term drift, affecting zero point stability of gyroscope and accelerometer, are integrated over time during the measurement process, resulting in an increasing attitude and navigation error. These errors can be reduced by periodic reset, shifting the problem to the need of on board accurate and precise absolute position and attitude references. A convenient way to overcome such limitation is here discussed making profit of Laben experience, matured as a company leader in on board data handling and space qualified GPS receiver systems, and by Honeywell as a world leader manufacturer of guidance and navigation packages. The approach would be a guideline for a novel scheme of G&NC architecture where a GPS receiver, performing both attitude and orbit determination, and a MIMU that includes three ring laser gyro and three accelerometers, are integrated in a common unit. In such a system, the measurements performed by the sensors are numerically filtered, removing high side frequency bandwidth noise components, to provide accurate and reliable input data for the attitude and navigation algorithms that will be executed by the embedded guidance computer. The results of such elaboration will be directly the actuation values to drive the space vehicle under both operative and non operative conditions, according to control laws established for the specific mission. With respect to other papers on the subject, the present introduces the characterization of the noise performances of the GPS tensor receiver, the first space qualified GPS receiver performing attitude and orbit determination -- designed and manufactured by Laben, and the analysis of the error model of the MIMU designed and manufactured by Honeywell. From the discussion of such error models a scheme for the sensors data fusion based on an extended Kalman filter is then proposed.

Garavelli, B.; Marradi, L.; Morgan, A.

1995-12-01

153

VLF navigation system  

US Patent & Trademark Office Database

A VLF navigation system suitable for highly accurate worldwide aircraft navigation utilizing existing VLF transmitting stations on a "dead reckoning" basis with initial and intermediate fixes. The system is enabled to utilize all existing VLF transmitting stations regardless of station frequency by novel receiver phase-locked loop means which normalizes all station frequencies to phase coherent independent data signals of a common working frequency. In one form of the invention, utilizing hyperbolic coordinates, both RF stations of each station pair utilized for computation are such VLF transmitting stations; while in another form of the invention, utilizing Rho-Rho coordinates, one RF station of each station pair is an on-board frequency standard normalized to the common working frequency, and the other station of each pair is one of the VLF transmitting stations. Computer means, which may be part of the "on-board" equipment, selects station pairs for optimum station geometry and range, and by comparing the phase differences between the phase coherent data signals for respective station pairs, determines a .DELTA. time and hence a .DELTA. position in suitable coordinates from the initial or intermediate calibration point. Novel multiplexing and counting means, and logic circuitry associated therewith, enable a single counting means to be rapidly sequentially employed by the computer to make the time difference comparison for a series of station pairs. The system is extremely accurate for a number of reasons, including but not limited to the inherent frequency stability of VLF transmitting stations (which are generally atomic clock controlled); the inherent minimal distortion of VLF electromagnetic signals over very long ranges; the fact that errors are not cumulative in the system; and a station pair averaging capability which decreases random errors and permits rejection of the defective signals.

1976-02-03

154

The Honeywell\\/DND helicopter integrated navigation system (HINS)  

Microsoft Academic Search

The development of prototype of a high-performance, fault-tolerant navigation system for Canada's anti-submarine-warfare helicopter is discussed. HINS consists of three primary navigation subsystems (an F 3INS, a five channel P-code GPS (global positioning system), and a Doppler velocity sensor) and three secondary sensors (a strapdown magnetometer, a vertical gyro, and an air data system). The system is designed to blend

G. West-Vukovich; J. Zywiel; B. M. Scherzinger; H. Russell; S. Burke

1989-01-01

155

Development of high precision and multifunctional timing system using integrated GPS\\/BD receiver  

Microsoft Academic Search

A highly precise and multifunctional timing system using the self development integrated GPS\\/BD time receiver is presented in this paper. The authors firstly designed an integrated GPS\\/BD (compass or Beidou navigation system of China) time receiver for time and frequency synchronization in a local network, and describing the main issues and the solution of the receiver implement in detail, and

Li Gun; Wu Fu-ping; Wei Jing-fa; Huang Xian-he

2008-01-01

156

Drishti: An Integrated Navigation System for Visually Impaired and Disabled  

Microsoft Academic Search

Drishti is a wireless pedestrian navigation system. It integrates several technologies including wearable computers, voice recognition and synthesis, wireless networks, Geographic Information System (GIS) and Global positioning system (GPS). Drishti augments contextual information to the visually impaired and computes optimized routes based on user preference, temporal constraints (e.g. traffic congestion), and dynamic obstacles (e.g. ongoing ground work, road blockade for

Abdelsalam Helal; Steven Edwin Moore; Balaji Ramachandran

2001-01-01

157

Wellborne inertial navigation system  

SciTech Connect

A phototype wireline tool which includes a downhole inertial platform and a surface computer to spatially map a well is described. The hardware consists of a single-gimbaled inertial platform with accelerometers and gyros to obtain three-axis motion information. The gyroscope and accelerometer outputs are transmitted to a computer at the surface which calculates probe attitude relative to north, east, and vertical. Double integration of the accelerometer data provides the position information. A conventional 7-conductor wireline is used for the system data transmission. System accuracy is enhanced by advances made in the computer software which processes the data received from the tool. The software uses statistical sampling estimation to obtain optimal estimates of the system errors. Measurement errors are determined by periodically stopping the tool during the logging procedure and observing the indicated velocity measurements. This procedure, known as Kalman filtering, results in increased accuracy of the data. Present mapping systems have an X-Y-Z location accuracy of +- 100 to +- 200 feet for a typical well depth of 10,000 feet. Test results show that the new system is accurate to about +- 1 foot per 1000 feet of well depth. Unlike conventional systems, the inertial navigator does not require any sort of projection of the cable length (which may not be accurately known). Also this system provides continuous data throughout the wellbore and logging speeds on the order of 10 ft/sec appear possible. The hardware and software associated with this mapping system are described and the recent field test results are reported.

Kelsey, J.R.

1983-01-01

158

Navigating low altitude satellites using the current four Navstar/GPS satellites  

NASA Astrophysics Data System (ADS)

It is shown that Landsat 4 can be quite accurately navigated over CONUS throughout most of the year using only the four fully operational GPS satellites. It is noted that the Landsat 4 mission covers only a very small fraction of the earth's surface. Typically, only two out of the roughly fourteen and one-half orbits per day are used and only five to six minutes of each orbit. The fact that only the north to south passes over CONUS are made use of may increase the accuracy in navigation. It is assumed that whenever a Navstar/GPS satellite is visible, Landsat 4 will track the satellite; since the altitude of Landsat 4 is 705 km, it can observe a GPS satellite with an elevation mask angle of -24 deg. This may be overly optimistic in that it does not consider possible coverage limitations of the GPS antenna on Landsat 4. It is noted, however, that with post-mission orbit determination, both past and future tracking data will be used. In this case the accuracy in determining the position of Landsat 4 should be better than the results presented here.

Jorgensen, S.

159

Application of interval and fuzzy techniques to integrated navigation systems  

Microsoft Academic Search

The paper deals with the development of a new algorithm to be used by an INS (Integrated Navigation System) for carrying out accurate position estimation for different types of surface vehicles, including cars and ships. The proposed algorithm combines a neuro-fuzzy Kalman filter with a map matching method, in order to improve the effective real-time system performance when a GPS

Antonio Tiano; Antonio Zirilli; Fausto Pizzocchero

2001-01-01

160

A GLOBAL POSITIONING SYSTEM (GPS) PRIMER  

Microsoft Academic Search

ABSTRACT The Global Positioning System (GPS) has been designed to enable one to determine one’s position in a latitude - longitude reference frame on or near the Earth to within several meters. Given that the Earth is an oblate spheroid (that is, ellipsoidal), a reference ellipsoid must be defined along with a latitude - longitude convention. The GPS uses a

Robert Augustson

2003-01-01

161

Development of a regional tropospheric delay model for GPS-based navigation with emphasis to the Indian Region  

NASA Astrophysics Data System (ADS)

The accuracy of Global Navigation Satellite System (GNSS), aimed to support precise positioning for aircraft navigation globally by coordinating different regional augmentation systems, is limited by the extent to which the atmospheric propagation delay of microwave signals can be modeled. An algorithm is developed for modeling the tropospheric delay based on mean meteorological parameters. A Region-specific Tropospheric Delay (RTD) model is developed exclusively for the Indian region using meteorological data from the Indian subcontinent, as a part of GPS Aided Geo Augmented Navigation (GAGAN) program. The applicability of this model is examined in the context of the global model used in Wide Area Augmentation System (WAAS), developed employing meteorological data mostly from North American continent, by comparing the estimated zenith tropospheric delay (ZTD) with those obtained from regional models employing measured atmospheric parameters at the surface. The rms deviation of ZTD estimated using RTD model from that of the surface model is found to be ˜5 cm. A further validation by comparing with GPS measurements from two IGS stations at Bangalore and Hyderabad showed that predictions made using the RTD model are within an rms deviation of ±5 cm while those using WAAS model is ±7 cm. Maximum value of the residual error for RTD model is ˜15 cm, which corresponds to a ˜0.5 m error in the vertical coordinates for the lowest satellite elevation angles usually encountered.

Parameswaran, K.; Saha, Korak; Suresh Raju, C.

2008-08-01

162

A Regional Tropospheric Delay Model for the Indian Subcontinent with Application to GPS Based Aircraft Navigation  

NASA Astrophysics Data System (ADS)

Application of Global Positioning System (GPS) in satellite-based navigation essentially requires a priori knowledge of the tropospheric refraction effect of GPS signal. The tropospheric delay estimated by ray tracing through the earth's atmosphere employing appropriate altitude profile of refractivity, is modeled in terms of measurable surface atmospheric parameters such as pressure, temperature, humidity as well as columnar water vapor for different locations over the Indian subcontinent using the upper air data (Radiosonde measurements). Different analytical forms are examined for this purpose. These site-specific surface models for zenith hydrostatic delay (ZHD) and wet (non-hydrostatic) delay are first generated for eighteen different selected locations over the continent covering different climatic region, over a geographical extend 8oN-33oN and 60oE-90oE. Taking all these models into account a Unified surface model that in principle is applicable for the entire subcontinent is derived. In a limiting case when the surface measurements are not available they are to be modeled based on the geographical coordinate and time (day of the year). For this the UNB model employed in WAAS (US), developed based on U.S standard supplements, and is examined over the Indian tropical region. This study extended further by developing a Region-specific model using five years daily atmospheric data over the Indian subcontinent which coupled to the Unified surface model provides a Regional Tropospheric Delay (RTD) model. This model is more accurate over Indian region. Since RTD does not involve any real time measured atmospheric parameters and relies only on mean model values, the prediction using this model is inferior to that estimated based on surface measurements. The maximum uncertainty of RTD model is 8.2cm and the minimum uncertainty is 0.86cm (at one sigma level) depending on the location, while the unified model with real-time measured inputs provides the same with an uncertainty between 5.2cm (maximum) and 0.65cm (minimum). A further validation by comparing with GPS measurements from two IGS stations at Bangalore and Hyderabad showed that predictions made using the RTD model are within an rms deviation of +5.0 cm while those using UNB model is +7.0 cm. Under extreme weather conditions these periodic (RTD, UNB) models have limitations which can be reduced by using the NCEP/NCAR reanalysis data.

Saha, Korak; Saha, Korak; Raju C, Suresh; Parameswaran, Krishnaswamy

163

GPS Basics  

NSDL National Science Digital Library

The Federal Aviation Administration maintains the graphically impressive Global Positioning System (GPS) Basics Web site. From the history of the global positioning system and how it works to governmental policy that controls its use, this site does a good job of explaining all facets of what GPS is about without being overly technical. Interested visitors can explore some of the other links that cover satellite navigation topics as well, such as GPS programs; a library of documents, fact sheets, press releases, and news; frequently asked questions; links; and more. Anyone interested in mapping, navigation, or similar subjects will enjoy exploring the interesting information provided on this well designed site.

164

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR OPERATION AND INITIALIZATION OF THE MAGELLAN GPS SATELLITE NAVIGATOR (UA-F-22.1)  

EPA Science Inventory

The purpose of this SOP is to describe the general procedures for the operation and initialization of the Magellan Global Positioning System (GPS) Satellite Navigator. This procedure was followed to ensure consistent data retrieval during the Arizona NHEXAS project and the "Bord...

165

Road profile recognition for autonomous car navigation and Navstar GPS support  

Microsoft Academic Search

We discuss autonomous car navigation based on updating dead reckoning (DR) by road profile recognition (RPR). The navigation system requires sensors to detect changes in altitude and driving direction which are installed in modern cars for different purposes (e.g. ABS sensors). The layout of the navigation system is discussed and simulations are carried out over driving distances of approximately 150

W. Holzapfel; M. Sofsky; U. Neuschaefer-Rube

2003-01-01

166

The impact of expected satellite availability on Global Positioning System (GPS) accuracy  

Microsoft Academic Search

An assessment of GPS navigation accuracy over the next few years is given, taking into account the availability of satellites for the GPS satellite constellation. It is pointed out that constellation build-up scheduling and the GPS satellite failure-replacement process will continue to yield degraded GPS navigation accuracy through 1994 and, perhaps, beyond. Recommendations for improving the effectiveness of GPS are

G. Siebert

1988-01-01

167

Fault detection combining interacting multiple model and multiple solution separation for aviation satellite navigation system  

Microsoft Academic Search

In civil aviation applications, satellite failures yield unacceptable positioning errors when using the Global Positioning System (GPS). To ensure the user security, the navigation system has to fulfill stringent performance requirements. Thus, detecting and excluding the faulty GPS measurements is necessary prior to estimating the mobile location. Classical fault detection algorithms based on Kalman filters (KF) are sensitive to the

Frederic Faurie; Audrey Giremus; Eric Grivel

2009-01-01

168

Low cost navigation system for UAV's ? ? This article was presented at ODAS 2004  

Microsoft Academic Search

This paper describes the development of a navigation system for SIVA family of UAVs that incorporates measurements from low cost solid state IMU and magneto-resistive magnetometer, single receiver inexpensive GPS, and absolute and differential pressure transducers. The navigator is composed of three modules: an attitude estimator, a position and velocity estimator and a mission management module. All the UAV navigation,

Sergio de La Parra; Javier Angel

2005-01-01

169

GPS Guide from Garmin  

NSDL National Science Digital Library

The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of 24 satellites placed into orbit by the U.S. Department of Defense. GPS was originally intended for military applications, but in the 1980s, the government made the system available for civilian use. GPS works in any weather conditions, anywhere in the world, 24 hours a day. There are no subscription fees or setup charges to use GPS. This site from Garmin presents a GPS guide for beginners and instructions on using a GPS with paper maps. Both documents are available for download in PDF format.

2010-10-22

170

Low Earth orbit satellite navigation errors and vertical total electron content in single-frequency GPS tracking  

NASA Astrophysics Data System (ADS)

In the context of space applications, the GPS system is presently a well-established and accepted tracking system. To meet the basic navigation requirements, most satellites in a low Earth orbit are equipped with single-frequency GPS receivers that measure the coarse acquisition code as well as the L1 phase. However, the resulting kinematic navigation solutions exhibit systematic position errors caused by elevation-dependent ionospheric path delays. In this study a simple analytical model is established, which quantitatively relates the position error to the vertical electron content and the mapping function. This model substantiates the empirical evidence of a mean radial offset that increases in proportion to the total electron content above the satellite. It is furthermore shown that the ratio between this offset and the vertical ionospheric path delay depends on the applied elevation mask angle. Representative ratios of 3-5 are obtained for the mapping function of the Lear ionosphere model and elevation cutoff angles of 10°, 5°, and 0°. This analytical result has further been confirmed by signal simulator tests as well as flight data of the CHAMP satellite.

Garcia-Fernã Ndez, Miquel; Montenbruck, Oliver

2006-10-01

171

Application of Global Positioning System (GPS) in Earth Sciences teaching  

Microsoft Academic Search

The purpose of this article is use GPS(Global Positioning System) equipment to applying in GIS teaching. To find the best way on using GPS. GPS device combine the software Google Earth , it will provide the whole world map for us. People can use GPS relation device for science explorer, recording objection on earth move track. The Global position system

Rong-Jyue Fang; Ken-I Su; Hsin-Chang Lu; Cheng-Chung Wang; Chin-Chih Lin

172

Designing Navigation Support in Hypertext Systems Based on Navigation Patterns  

ERIC Educational Resources Information Center

|In this paper, we present two studies designed to help students navigate effectively and learn from a hypertext system, CoMPASS. Our first study ("N" = 74) involved an analysis of students' navigation patterns to group them into clusters, using a "k"-means clustering technique. Based on this analysis, navigation patterns were grouped into four…

Puntambekar, Sadhana; Stylianou, Agni

2005-01-01

173

Trends in inertial systems technology for high accuracy AUV navigation  

Microsoft Academic Search

Medium accuracy inertial systems of the 1 nautical mile per hour class, enjoyed significant acceptance in the market for land survey systems in the early 1970's-prior to the introduction of GPS. This occurred because such systems could be implemented with software that capitalized on “zero velocity updates” (ZUPTS) which enabled the resultant system to achieve real-time navigation accuracies of a

J. R. Huddle

1998-01-01

174

Inmarsat integrity channels for global navigation satellite systems  

NASA Astrophysics Data System (ADS)

The navigation packages on Inmarsat-3 are aimed at providing a GPS-compatible signal to enhance integrity for global navigation satellite systems (GNSS) users by relaying integrity data from a ground monitoring network and by providing an additional satellite in view. Investigations are currently under way to determine if the GNSS Integrity Channel (GIC) transmission can provide supplemental data besides integrity, i.e., wide area differential corrections. The ranging GIC signal will improve navigational accuracy for all users, and may also be employed as a precise stand-alone time reference.

Kinal, George V.; Nagle, Jim; Lipke, Dave W.

1992-08-01

175

Satellite radio navigation and dead reckoning systems combining for vehicle location  

Microsoft Academic Search

The author addresses the problem of how to reduce the cost, increase the reliability and meet the precision requirements to vehicle location systems operating as part of an on-board navigation system. An approach to the problem is to combine a Global Positioning System (GPS) navigation receiver with traditional dead reckoning systems, and to use processing to calculate the current position.

V. L. Koliadin

1993-01-01

176

A Report on GPS and Galileo Time Offset Coordination Efforts  

Microsoft Academic Search

Precise timing is an inherent part of radio navigation systems like GPS and Galileo. This paper update progress on cooperative efforts between the GPS system and the Galileo system to harmonize the underlying Navigation time scales of both systems to better facilitate a combined GPS\\/Galileo navigation solution. This paper also outline cooperative experimentation and demonstration that will be conducted during

J. H. Hahn; E. D. Powers

2007-01-01

177

Assessing the Navigation Data Input to Aircraft Flight Management Systems  

NASA Astrophysics Data System (ADS)

This paper gives details of the failure rates and the failure modes experienced with SPS GPS receivers certificated for aviation use to the TSO-C129 specification. These failure rates are significant compared to those from other modern avionics and the rates are comparable to that currently experienced from un-scheduled failures in the GPS signals-in-space. To achieve certification, Flight Management System (FMS) design should consider the way in which the satellite navigation receivers fail. The paper also gives details concerning the 2-D errors that have been experienced with these receivers, and indicates further work that needs to be done with C 129a receivers.

Nisner, P. D.; Johannessen, R.

1998-09-01

178

Ship satellite-navigation systems (2nd revised and enlarged edition)  

NASA Astrophysics Data System (ADS)

Principles for the construction of automated satellite-based navigation systems for ships are reviewed. Topics covered include satellite navigation principles; the apparent motion of navigation satellites; the analysis of ephemeris observational errors; and the optimization of both equipment solutions and algorithms for navigation information processing. The present theoretical analysis is supported by results of mathematical modeling, by geometric interpretation of separate positions, and by examples of applications in the Transit and Navstar GPS systems.

Volosov, P. S.; Dubinko, Iu. S.; Mordvinov, B. G.; Shinkov, V. D.

179

MOST-NNG: An Accessible GPS Navigation Application Integrated into the MObile Slate Talker (MOST) for the Blind  

Microsoft Academic Search

\\u000a Over the recent years, GPS navigation has been attracting a growing attention among the visually impaired. This is because\\u000a assistive technologies can obviously be based on commercially available solutions, as the GPS capable hand-held devices entered\\u000a the size range of the ordinary mobile phones, and are available at an ever more affordable price, now providing a real choice\\u000a for a

Norbert Markus; András Arató; Zoltán Juhász; Gábor Bognár; László Késmárki

2010-01-01

180

VEHICULAR NAVIGATION IN URBAN CANYONS USING A HIGH SENSITIVITY GPS RECEIVER AUGMENTED WITH A MEDIUM-GRADE IMU  

Microsoft Academic Search

In order to improve performance, this paper investigates the augmentation of a HSGPS receiver with a medium-grade IMU and a map-matching technique. Most of the up-to-date work in the area of GPS\\/INS integration for vehicular navigation deals with cases when a vehicle is driven into downtown areas from open sky areas allowing accurate GPS initialization before the vehicle enters urban

O. Mezentsev; J. Collin; G. Lachapelle

181

Navy Navigation Satellite System status  

NASA Astrophysics Data System (ADS)

It is pointed out that the Navy Navigation Satellite System (TRANSIT) provides a global basis for operational navigation and for Doppler surveying. TRANSIT is widely used throughout the U.S. Navy and by commercial shipping as a worldwide highly reliable and highly precise all-weather navigation system. The operational constellation contains currently six satellites. TRANSIT was developed to support the Polaris missile firing submarine and has been in continuous use by the U.S. Navy Strategic Systems Project Office since 1963. It was released for public use by Presidential directive in 1967. Attention is given to a systems overview, the operational satellite configuration, the Nova satellite configuration, the tracking network, and ionospheric refraction correction. The current status of TRANSIT is briefly examined. It is found that TRANSIT remains a reliable aid to all which utilize it.

Hoskins, G. W.

182

On-Line Smoothing for an Integrated Navigation System with Low-Cost MEMS Inertial Sensors  

PubMed Central

The integration of the Inertial Navigation System (INS) and the Global Positioning System (GPS) is widely applied to seamlessly determine the time-variable position and orientation parameters of a system for navigation and mobile mapping applications. For optimal data fusion, the Kalman filter (KF) is often used for real-time applications. Backward smoothing is considered an optimal post-processing procedure. However, in current INS/GPS integration schemes, the KF and smoothing techniques still have some limitations. This article reviews the principles and analyzes the limitations of these estimators. In addition, an on-line smoothing method that overcomes the limitations of previous algorithms is proposed. For verification, an INS/GPS integrated architecture is implemented using a low-cost micro-electro-mechanical systems inertial measurement unit and a single-frequency GPS receiver. GPS signal outages are included in the testing trajectories to evaluate the effectiveness of the proposed method in comparison to conventional schemes.

Chiang, Kai-Wei; Duong, Thanh Trung; Liao, Jhen-Kai; Lai, Ying-Chih; Chang, Chin-Chia; Cai, Jia-Ming; Huang, Shih-Ching

2012-01-01

183

A global positioning system (GPS) interference electronics support measure (ESM) payload system for unmanned aerial vehicles (UAVs)  

Microsoft Academic Search

Modern battlefields depend on GPS for precision navigation and timing. Unfortunately, GPS signals are very-low level and GPS interference, both intentional and unintentional, can severely degrade GPS performance. Unmanned Aerial Vehicles (UAV), which have proven their value on the battlefield, rely heavily on GPS for navigation and flight integrity. Key to continued mission success for UAVs is enhanced anti-jamming capabilities.

Timothy J. Wurth; Jeffrey S. Wells

2004-01-01

184

The signal design of present satellite navigation system and its inspiration  

NASA Astrophysics Data System (ADS)

Navigation signals are the basis of satellite navigation systems, which determine the navigation systems' performance (such as tracking accuracy, anti-interference capability etc.), and are determined by some constraints (such as radio frequency resources, construction cost, technology level etc.). The aim of signal design is to select "proper" signals considering these above factors and make tradeoffs between performance and constraints. This paper will summarize the signal structure evolution of present satellite navigation and conclude some principles and issues which will be greatly valuable to our 2nd satellite navigation system. There's four main satellite positioning systems presently, the U.S. Global Positioning System (GPS), the Russian Global Navigation Satellite System (GLONASS), the Europe Galileo satellite navigation system and the Chinese BD-1 satellite positioning system. Among these systems, the signal characteristics of GPS and Galileo are good reference to our 2nd satellite navigation system. The improvement of GPS signals is a main aspect of GPS modernization. The aim of GPS modernization is mainly to modernize its signal structure so as to improve the whole systems' performance. The signal structure of Galileo has been revised for several times, and its present signal is the results of long time signal design. From GPS modernization and Galileo signals status, we can summarize some key specifications of navigation signals and some technologies to support these specifications. Based on this, we'll discuss some problems which should be attentive in our country's 2nd satellite navigation system and give some suggestions. This paper is organized into five sections. The first section will give a brief introduction of present satellite navigation system and their main features. Section two will review the GPS and Galileo signals structure evolution, including GPS modernization, Galileo signals status and the comparison of two systems' signals. In the third section, the relationship between signal parameters and system performance will be analyzed, including RF signal characteristics, modulation type, ranging code (such as code type, length and rate) and navigation data. In section four we will discuss some inspiration and technologies concerning our 2nd satellite navigation system, such as the use of multiple frequency signals (ionospheric delay estimation and carrier ambiguity resolution), pilot tones & dataless channel, binary offset carrier (BOC) modulation, and so on. The last section is conclusion, in which the whole paper will be retrospected and some useful conclusion will be given.

Zhu, Xiangwe; Wang, Feixue

2005-11-01

185

The transmission link of CAPS navigation and communication system  

Microsoft Academic Search

The Chinese Area Positioning System (CAPS) is based on communication satellites with integrated capability, which is different\\u000a from the Global Positioning System (GPS), the International Maritime Satellite Organization (Inmarsat) and so on. CAPS works\\u000a at C-band, and its navigation information is not directly generated from the satellite, but from the master control station\\u000a on the ground and transmitted to users

Junxia Cui; Huli Shi; Jibin Chen; Jun Pei

2009-01-01

186

Wave remote sensing system by GPS  

Microsoft Academic Search

It is well known that an observation of the long period gravity wave is very difficult to observe for its long period and small amplitude. In our recent research, an integrated wave remote sensing system utilizing multi-path GPS signals reflected from sea surface is proposed to measure accurate wavelength for long period gravity wave. The system is equipped with an

Jian Cui; Nobuyoshi KOUGUCHI; Akihiro IKAWA; Shigeyuki OKUDA; Yasuo ARAI

2010-01-01

187

GPS-translator processing system for ERIS  

Microsoft Academic Search

The author describes the requirements, design features, and capabilities of a Global Positioning System (GPS) based on the translator processing system (TPS) being procured for a tracking application for the US Army Strategic Defense Command's (USASCD) exoatmospheric reentry vehicle interceptor subsystem (ERIS) project. The TPS provides the real-time position and velocity information for the target and the interceptor vehicles of

Sultan Mahmood

1988-01-01

188

SpaceNav - A high accuracy navigation system for space applications  

NASA Astrophysics Data System (ADS)

The technology of the SpaceNav-system is based on research performed by the Institute of Flight Guidance and Control at the Technical University of Braunschweig, Germany. In 1989 this institute gave the worlds first public demonstration of a fully automatic landing of an aircraft, using inertial and satellite informations exclusively. The SpaceNav device components are: Acceleration-/Gyro Sensor Package; Global Positioning System (GPS) Receiver/optional more than one; Time Reference Unit; CPU; Telemetry (optional); and Differential GPS (DGPS) Receiver (optional). The coupling of GPS receivers with inertial sensors provides an extremely accurate navigation data set in real time applications even in phases with high dynamic conditions. The update rate of this navigation information is up to 100 Hz with the same accuracy in 3D-position, velocity, acceleration, attitude and time. SpaceNav is an integrated navigation system, which operates according to the principle of combining the longterm stability and accuracy of GPS, and the high level of dynamic precision of conventional inertial navigation system (INS) strapdown systems. The system's design allows other aiding sensors e.g. GLONASS satellite navigation system, distance measuring equipment (DME), altimeter (radar and/or barometric), flux valve etc. to be connected, in order to increase the redundancy of the system. The advantage of such an upgraded system is the availability of more sensor information than necessary for a navigation solution. The resulting redundancy in range measurement allows real-time detection and identification of sensor signals that are incompatible with the other information. As a result you get Receiver Autonomous Integrity Monitoring (RAIM) as described in 'A Multi-Sensor Approach to Assuring GPS Integrity', presented by Alison Brown in the March/April 1990 issue of 'GPS World'. In this paper the author presents information about the principles of the Satellite Navigation System GPS, and the methods to improve performance and accuracy of this system necessary for understanding the advantages of the SpaceNav system.

Evers, H.-H.

189

Development of a DGPS\\/MEMS IMU Integrated System for Navigation in Urban Canyon Conditions  

Microsoft Academic Search

The aim of this paper is to develop a DGPS\\/MEMS INS integrated system, which is able to provide a navigation solution with accuracy levels appropriate for land vehicle navigation. The system achieves this aim by augmenting the standard GPS\\/INS Kalman filter with additional sensor error states, like scale factor errors and sensor turn on biases, which prevent the growth of

S. Godha; M. E. Cannon

190

Optimization of the Effective GPS Data Rate.  

National Technical Information Service (NTIS)

Ohio University's Avionics Engineering Center is performing research directed towards the integration of the NAVSTAR Global Positioning System (GPS) and the Inertial Navigation System (INS) for attitude and heading determination. The integration of GPS/IN...

D. S. Mcintyre

1990-01-01

191

Impact of propagation mechanisms on global navigation satellite system performance  

NASA Astrophysics Data System (ADS)

Propagation mechanisms have a detrimental effect on the accuracy of satellite positioning systems such as GPS and GLONASS. The ionosphere at times of high activity will cause the greatest error due to the propagation medium. This paper describes a dual GPS/GLONASS receiver that is capable of measuring the ionospheric delay in the measured GLONASS pseudo ranges using both the code and carrier phases. This allows the pseudo ranges to be corrected for ionospheric delay and a more accurate position solution to be calculated. This paper describes the receiver architecture and fundamental accuracy; receiver measurement noise and calibration are also discussed before the impact of propagation mechanisms on the measurements are investigated. The measurement of the line of sight ionospheric delay, from a GLONASS satellite, is shown and compared with the GPS transmitted ionospheric model. An example of GLONASS P code navigation is given with and without correction for the ionosphere.

Riley, Stuart; Daly, Peter; Raby, Peter

1994-07-01

192

Navigation System for the Blind  

Microsoft Academic Search

The research we are reporting here is part of our effort to develop a navigation sys-tem for the blind. Our long-term goal is to create a portable, self-contained system that will allow visually impaired individuals to travel through familiar and unfamiliar environments without the assistance of guides. The system, as it exists now, consists of the following functional components: (1)

Jack M. Loomis; Reginald G. Golledge; Roberta L. Klatzky

193

ION GPS-90; Proceedings of the 3rd International Technical Meeting of the Satellite Division of the Institute of Navigation, Colorado Springs, CO, Sept. 19-21, 1990  

NASA Astrophysics Data System (ADS)

Papers are presented on digital technology applied to airborne receivers, military GPS receivers for naval use, recent advances in pseudokinematic surveying, missing relativity effects in GPS, and the land-mobile GPS receiver. Also considered are a review of GLONASS system characteristics, tracking translated GPS signals, digital translators for GPS TSPI applications, a comparison of fixed and variable threshold RAIM algorithms, and fault tolerant GPS/inertial system design.

194

Spacecraft Autonomous Navigation for Earth Ground Track Repeat Orbits Using GPS  

Microsoft Academic Search

This paper describes a simple empirical strategy for computing maneuver times and magnitudes autonomously for Earth orbiting spacecraft with a ground track repeat requirement. Ground track maintenance requires frequent in-plarte drag rtiake up maneuvers. Out-of-plane maneuvers are required less frequently, thus are not addressed by this simple approach. Using the Global Positioning System (GPS), tracking and orbit determination functions are

Ilmothy N. Munson; Mark A. Vincent

195

GPS-Based Satellite Tracking System for Precise Positioning  

Microsoft Academic Search

NASA is developing a Global Positioning System (GPS) based measurement system to provide precise determination of Earth satellite orbits, geodetic baselines, ionospheric electron content, and clock offsets between worldwide tracking sites. The system will employ variations on the differential GPS observing technique and will use a network of nine fixed ground terminals. Satellite applications will require either a GPS flight

THOMAS P. YUNCK; WILLIAM G. MELBOURNE; C. L. Thoenton

1985-01-01

196

Navigating in the Galileo test environment with the first GPS\\/Galileo multi-antenna-receiver  

Microsoft Academic Search

Array processing is a very promising technology for mitigation and detection of radio interference in receivers of satellite navigation systems. This paper presents early results of a multi-antenna receiver measurement campaign in Berchtesgaden GATE.

M. Cuntz; M. Heckler; S. Erker; A. Konovaltsev; M. Sgammini; A. Hornbostel; A. Dreher; M. Meurer

2010-01-01

197

Flight Evaluation of GPS Precise Point Positioning Software for Helicopter Navigation  

NASA Astrophysics Data System (ADS)

In 2007 development and assessment of a precise point positioning (PPP) software for land vehicular navigation have been reported. This paper presents one phase of the continued study at NDA for further extension of the software to helicopter navigation. For 3D users, the height-dependent tropospheric delay is a critical factor, and so the sophisticated correction models and parameter estimation strategies have to be investigated to mitigate the delay effect. Since the precise positioning results become available only after the filter convergence and the filter generally converges rather slowly, speeding up the convergence has to be taken into special attention. In this paper we propose some new ideas to cope with this problem, and report the test using GPS helicopter flight data in post-processing. With proposed techniques including the variable Q and pseudo-observation concept, we show that point positioning accuracy at about decimeter level both horizontally and vertically can be achieved with improved convergence within about half an hour. We also show that the use of the high-rate (30-second) satellite clocks rather than the 5-minute clocks further improves positioning accuracy at sub-decimeter level in each 3D coordinate.

Shimizu, Yutaka; Murata, Masaaki

198

The MARCOR GPS mobile data system  

NASA Astrophysics Data System (ADS)

Market research revealed several key demands for an Automatic Vehicle Location (AVL) Global Positioning System (GPS) radio. The demands were for minimization of urban building blockage, easy programmability to minimize mobile data transmission costs, high accuracy for street map level coordination, interface capability with non-digital Specialized Mobile Radios (SMR), and a selling price close to that of alternatives such as Signposts and Loran-C. A team of experts was assembled to surmount these challenges and deliver a GPS radio for $500 to $1000, which operates at high accuracy in an urban environment and is plug-compatible with nearly all vehicle radios. Among the engineering and production breakthroughs described here are a unique Simultrac (Trademark) approach to satellite tracking, enabling up to eight GPS satellites to be used for position determination with a 2-channel receiver, and a receiver-in-a-microphone design. A powerful Application Specific Integrated Circuit (ASIC) allowed GPS to be brought within easy reach of millions of AVL users such as bus, taxi, and delivery vehicle fleets.

Rothblatt, Martin

1991-09-01

199

Micro air vehicle navigation system  

Microsoft Academic Search

A description of the design, operation, and test results of a Micro-Electro-Mechanical (MEMS)-based navigation system for the Micro Air Vehicle (MAV) is presented. The MAV is a small Unmanned Aerial Vehicle (UAV) built by Honeywell. It is one of the first applications to use Honeywell's new HG1930 MEMS inertial measurement unit (IMU). The raw IMU measurements are transmitted via a

B. B. Mohr; D. L. Fitzpatrick

2008-01-01

200

Predicting Solar Disturbance Effects on Navigation Systems  

NASA Astrophysics Data System (ADS)

A variety of operational systems are vulnerable to disruption by solar disturbances brought to the Earth by the solar wind. Of particular importance to navigation systems are energetic charged particles which can generate temporary malfunctions and permanent damage in satellites. Modern spacecraft technology may prove to be particularly at risk during the next maximum of the solar cycle. In addition, the associated ionospheric disturbances cause phase shifts of transionospheric and ionosphere-reflected signals, giving positioning errors and loss of signal for GPS and Loran-C positioning systems and for over-the-horizon radars. We now have sufficient understanding of the solar wind, and how it interacts with the Earth's magnetic field, to predict statistically the likely effects on operational systems over the next solar cycle. We also have a number of advanced ways of detecting and tracking these disturbances through space but we cannot, as yet, provide accurate forecasts of individual disturbances that could be used to protect satellites and to correct errors. In addition, we have recently discovered long-term changes in the Sun, which mean that the number and severity of the disturbances to operational systems are increasing.

Lockwood, M.; Wild, M. N.; Stamper, R.; Davis, C. J.; Grande, M.

201

NAVSTAR GPS Simulation and Analysis Program.  

National Technical Information Service (NTIS)

This study assesses the capability of the planned NAVSTAR Global Positioning System (GPS) to meet civil navigation requirements. When it becomes operational in about 1983, NAVSTAR GPS will provide accurate two-dimensional and three-dimensional service to ...

J. Kraemer J. Vilcans N. Knable R. M. Kalafus

1983-01-01

202

Pre-Flight Testing of Spaceborne GPS Receivers Using a GPS Constellation Simulator.  

National Technical Information Service (NTIS)

The NASA Goddard Space Flight Center (GSFC) Global Positioning System (GPS) applications test facility has been established within the GSFC Guidance Navigation and Control Center. The GPS test facility is currently housing the Global Simulation Systems In...

S. Kizhner E. Davis R. Alonso

1999-01-01

203

Pre-Flight Testing of Spaceborne GPS Receivers using a GPS Constellation Simulator.  

National Technical Information Service (NTIS)

The NASA Goddard Space Flight Center (GSFC) Global Positioning System (GPS) applications test facility has been established within the GSFC Guidance Navigation and Control Center. The GPS test facility is currently housing the Global Simulation Systems In...

S. Kizhner E. Davis R. Alonso

1999-01-01

204

Prototype HSR Accurate Low-Cost GPS Locomotive Location System IDEA Program Final Report.  

National Technical Information Service (NTIS)

This was a project to develop a high-speed rail train navigation system to accurately determine train location, including determining on which of two or more parallel tracks a locomotive is located. The system includes a three-receiver, three-antenna GPS ...

K. T. Mueller

2003-01-01

205

Changing Interfaces Using Natural Arm Posture - A New Interaction Paradigm for Pedestrian Navigation Systems on Mobile Devices  

Microsoft Academic Search

This paper presents a new interaction technique, which is based on arm posture recognition, for mobile computing devices to switch between dif- ferent visualization modes seamlessly. We implemented a pedestrian navigation system on Pocket PC, which is connected to a GPS receiver and an inertial ori- entation tracker. In the global coordinate system, user's position is tracked with GPS data,

Ceren Kayalar; Selim Balcisoy

2007-01-01

206

Global navigation satellite system adoption in Latvia  

NASA Astrophysics Data System (ADS)

We have tested together one permanent and two semi permanent GPS base stations with separations in between stations up to 50km in Riga urban region and achieved good results. Our aim is to distribute differential GPS and later on RTK corrections to end-users all over Latvia. We participate into European Position Determination system (EUPOS) activities, too. On the base of close international cooperation in near future we are eager to establish GPS network containing 28 permanent stations. The proposed project of national importance has common interest among many ministries and companies. The principles of base stations distribution, communication problems as well as software and processing solutions are going under discussion.

Kaminskis, J.; Zhagars, J.

2003-04-01

207

GPS Precise Point Positioning Methods Using IGS Products for Vehicular Navigation Application  

Microsoft Academic Search

Recently, GPS precise point positioning (PPP) has attracted the precision GPS community as it can provide the cm-dm level positioning accuracy with a single GPS receiver, which is almost comparable to that obtained by DGPS. We have developed a generic PPP software. Assuming a dual frequency receiver and using IGS precise satellite ephemeris and clock, the software estimates position vector

Masatoshi Honda; Masaaki Murata; Y. Mizukura

2006-01-01

208

Recent developments for the Global Positioning System interference and navigation tool (GIANT)  

Microsoft Academic Search

The Global Positioning System (GPS) is a space based radionavigation system that provides accurate, continuous, worldwide service to passive users. GIANT is a one GPS-equipped platform versus many interference sources, constructive and repeatable simulation that is typically applied to determine navigation performance and operational effectiveness. GIANT runs on a PC, is US Government-owned, includes a user-friendly graphical interface for setup

G. L. Green; G. Gerten

2000-01-01

209

The GPS Class: Global Positioning Systems, Map, and Compass  

NSDL National Science Digital Library

This portal provides access to lessons and information about using Global Positioning Systems (GPS) in education. Materials include ideas for teaching and using GPS in educational curricula; websites, books, and other tools; and information on how to set up and use a GPS reciever. There is also information about setting up and using a compass with a topographic map and on converting GPS coordinates for use within a Geographic Information System (GIS). A section on Geocaching and Earthcaching provides tips on how to incorporate GPS treasure hunts into educational curricula and learning about Earth's environment and processes. Sample Geocaching courses are included.

210

Design and implementation of marine dumping area's monitoring system based on GPS\\/GPRS  

Microsoft Academic Search

In this paper, it advances the reasonable development programs of the waste dumping in the dumping areas and achieve the position, navigation and monitoring of the ship-borne navigation monitoring system which based on the GPS\\/ GPRS wireless remote monitoring technology on the embedded SPCE3200 platform. The software and the hardware which are consisted of a ship-borne information processing termination are

Guoliang Zou; Bing He; Dongmei Huang; Xianghong Kong

2010-01-01

211

Study on GPS attitude determination system aided INS using adaptive Kalman filter  

NASA Astrophysics Data System (ADS)

A marine INS/GPS (inertial navigation system/global positioning system) adaptive navigation system is presented in this paper. The GPS with two antennae providing vessel attitude is selected as the auxiliary system to fuse with INS. The Kalman filter is the most frequently used algorithm in the integrated navigation system, which is capable of estimating INS errors online based on the measured errors between INS and GPS. The conventional Kalman filter (CKF) assumes that the statistics of the noise of each sensor are given. As long as the noise distributions do not change, the Kalman filter will give the optimal estimation. However, the GPS receiver will be disturbed easily and thus temporally changing measurement noise will join into the outputs of GPS, which will lead to performance degradation of the Kalman filter. Many researchers introduce a fuzzy logic control method into innovation-based adaptive estimation Kalman filtering (IAE-AKF) algorithm, and accordingly propose various adaptive Kalman filters. However, how to design the fuzzy logic controller is a very complicated problem, which is still without a convincing solution. A novel IAE-AKF is proposed herein, which is based on the maximum likelihood criterion for the proper computation of the filter innovation covariance and hence of the filter gain. The approach is direct and simple without having to establish fuzzy inference rules. After having deduced the proposed IAE-AKF algorithm theoretically in detail, the approach is tested in the developed INS/GPS integrated marine navigation system. Real field test results show that the adaptive Kalman filter outperforms the CKF with higher accuracy and robustness. It is demonstrated that this proposed approach is a valid solution for the unknown changing measurement noise existing in the Kalman filter.

Bian, Hongwei; Jin, Zhihua; Tian, Weifeng

2005-10-01

212

Maritime and Aeronautical Satellite Navigation Systems  

Microsoft Academic Search

This paper inciudes a brief survey of the generic types of radio navigation aids, including satellite navigation; then a more detailed review of the TRANSIT and NAVSTAR systems, thus encompassing the principal developmental and operational satellite navigation systems. The precision and accuracy of these systems, their basic operating characteristics, and the ancillary equipment required for their operations will be covered.

J. Litton

1977-01-01

213

Receiver Acquisition Algorithms and Their Comparisons for BOC Modulated Satellite Navigation Signal  

Microsoft Academic Search

Now days, the satellite navigation system such as GPS is used world widely for many applications which are growing fast creating need of satellite navigation. Regional satellite navigation systems are growing now which uses similar frequency as GPS so it creates the interference to GPS signal. The use of the Binary Offset Carrier (BOC) modulated signal in incoming satellite navigation

Pooja V. Thakar; Hiren Mewada

2012-01-01

214

GPS: A New Constellation  

NSDL National Science Digital Library

This Air and Space Museum website provides detailed information about how GPS (Global Positioning System) works. Beginning with technology that existed before GPS, such as the sextant and the TRANSIT satellite, it provides information about land, air, and sea navigation, Earth mapping, land management, and scientific applications.

215

Performance of a dedicated VLBI system for TDRSS navigation  

NASA Astrophysics Data System (ADS)

Results of a covariance study to evaluate the performance of a proposed Very Long Baseline Interferometric (VLBI) system for TDRSS orbit determination (OD) are presented. This dedicated VLBI system consists of 4 one meter antennas for each TDRS positioned on orthogonal 6000 km baselines and uses a GPS signal for clock synchronization and calibration of measurement error sources. The performance of the VLBI system is compared with the current BRT system for support of TDRSS navigation. The criteria for evaluating the system performance is the TDRSS OD accuracy and the resulting navigation accuracy for two typical TDRSS users represented by a TOPEX type orbit and a Space Shuttle orbit. Based on the anticipated characteristics of a 1990 era VLBI system a factor of 20 improvement can be expected in the TDRSS OD accuracy. This translates into accuracy improvements ranging from factors of 3 to 10 for typical TDRSS users.

Ellis, J.

1984-08-01

216

Reconciling the Navigational Grid with the Inertial Navigation System.  

National Technical Information Service (NTIS)

The navigation grid overprinted on certain small scale navigation and planning charts published by the Defense Mapping Agency was originally intended for use in polar regions by navigators utilizing such techniques as celestial navigation and LORAN-C. The...

L. D. Wanner J. Hopkins

1987-01-01

217

Autonomous navigation system and method  

DOEpatents

A robot platform includes perceptors, locomotors, and a system controller, which executes instructions for autonomously navigating a robot. The instructions repeat, on each iteration through an event timing loop, the acts of defining an event horizon based on the robot's current velocity, detecting a range to obstacles around the robot, testing for an event horizon intrusion by determining if any range to the obstacles is within the event horizon, and adjusting rotational and translational velocity of the robot accordingly. If the event horizon intrusion occurs, rotational velocity is modified by a proportion of the current rotational velocity reduced by a proportion of the range to the nearest obstacle and translational velocity is modified by a proportion of the range to the nearest obstacle. If no event horizon intrusion occurs, translational velocity is set as a ratio of a speed factor relative to a maximum speed.

Bruemmer, David J. (Idaho Falls, ID); Few, Douglas A. (Idaho Falls, ID)

2009-09-08

218

Deep space navigation systems and operations  

Microsoft Academic Search

The history of the deep space navigation system developed by NASA is outlined. Its application to Mariner, Viking and Pioneer missions is reviewed. Voyager navigation results for Jupiter and Saturn are commented on and velocity correction in relation to fuel expenditure and computer time are discussed. The navigation requirements of the Gahleo and Venus orbiting imaging radar (VOIR) missions are

J. F. Jordan

1981-01-01

219

Study on costal intelligent navigation system  

Microsoft Academic Search

The safety and economy of ship transportation is always an important issue in the shipping worlds. Due to complex natural conditions, relatively narrow navigable range and high traffic density, coastal navigation is usually not only an accident-prone area but also the low shipping efficiency. Therefore, an intelligent navigation system for coastal sailing based on numerical forecasting of environmental factors and

Haibo Xia

2010-01-01

220

A wellbore inertial navigation system  

SciTech Connect

A prototype wireline tool which includes a downhole inertial platform and a surface computer to spatially map a well is described. The hardware consists of a single-gimballed inertial platform with accelerometers and gyros to obtain three-axis motion information. The gyroscope and accelerometer outputs are transmitted to a computer at the surface which calculates probe attitude relative to north, east, and vertical. Double integration of the accelerometer data provides the position information. A conventional 7-conductor wireline is used for the system data transmission. System accuracy is enhanced by advances made in the computer software which processes the data received from the tool. The software uses statistical sampling estimation to obtain optimal estimates of the system errors. Measurement errors are determined by periodically stopping the tool during the logging procedure and observing the indicated velocity measurements. This procedure, known as Kalman filtering, results in increased accuracy of the data. Present mapping systems have an X-Y-Z location accuracy of 100 to 200 feet for a typical well depth of 10,000 feet. Test results show that the new system is accurate to about 1 foot per 1000 feet of well depth. Unlike conventional systems, the inertial navigator does not require any sort of projection of the cable length (which may not be accurately known). Also, this system provides continuous data throughout the wellbore and logging speeds on the order of 10 ft/sec appear possible. The hardware and software associated with this mapping system are described and the recent field test results are reported.

Kelsey, J.R.

1983-02-01

221

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR OPERATION AND INITIALIZATION OF THE MAGELLAN GPS SATELLITE NAVIGATOR (UA-F-22.1)  

EPA Science Inventory

The purpose of this SOP is to describe the general procedures for the operation and initialization of the Magellan Global Positioning System (GPS) Satellite Navigator. This procedure was followed to ensure consistent data retrieval during the Arizona NHEXAS project and the Borde...

222

Review of the Status and Capabilities of Navstar GPS.  

National Technical Information Service (NTIS)

A general description is given of the Navstar Global Positioning System (GPS), together with a discussion of implications related to the possible use of GPS as an operational navigation system. Some evolving new techniques are discussed in the final part ...

N. van Driel

1992-01-01

223

Development and test results of a precision approach and landing capability for military aircraft using an embedded GPS\\/INS (EGI) system  

Microsoft Academic Search

Honeywell is engaged in the research and development of a Precision Approach and Landing (PAL) capability for the Embedded GPS\\/INS (EGI) airborne navigation system. This PAL EGI approach guidance is augmented with differential corrections from a local area differential GPS Satellite Landing System (SLS) ground station. The primary PAL EGI design goals are to meet military mission requirements, be interoperable

Joseph Elchynski; J. Kirkland; J. Conner

1998-01-01

224

Aided inertial navigation systems for underwater vehicles  

Microsoft Academic Search

This paper addresses the design and performance of precision autonomous navigation systems for underwater vehicles. The use of inertial navigation systems aided by velocity sensors and periodic position fixes is examined. Equipment such as the ship's log, the doppler sonar, the correlation velocity log, and position fixes using such systems as acoustic and magnetic benchmarks, and radio systems such as

Dan Johnson; Steve Eppig

1987-01-01

225

Time and Frequency Measurements Using the Global Positioning System (GPS)  

Microsoft Academic Search

This paper describes how Global Positioning System (GPS) satellite signals are used in time and frequency metrology. It discusses how a GPS receiver can provide a reference signal for frequency calibrations and time synchronization. It also explains the several types of time and frequency measurements that utilize GPS signals. These include one-way or direct reception measurements, single and multi-channel common-view

Michael A. Lombardi; Lisa M. Nelson; Andrew N. Novick; Victor S. Zhang

226

Low-cost, Drift-free DGPS Locomotive Navigation System. High Speed Rail IDEA Program.  

National Technical Information Service (NTIS)

This project developed a high-speed rail train navigation system to accurately determine train location, including on which of two or more parallel tracks a locomotive is located. The system includes a three-receiver, three-antenna GPS heading reference s...

K. T. Mueller

2003-01-01

227

Basic Mars Navigation System For Local Areas  

NASA Astrophysics Data System (ADS)

Introduction: This project has been first set up as a basic solution in navigation during EVA (extra-vehicular activities) in the Mars Society Desert Research Station in the desert of Utah. The main idea is to keep the system as simple as possible so that it can be easily adaptable and portable. The purpose of such a device is to tell the astronauts in EVA where they roughly are and then letting them reaching different points in avoiding any risky way. Thus the precision needed has not to be really high: even if it is about 50m, every astronaut can then look on a map and be able to design a way to another point. This navigation system will improve the safety of the EVA as it is an added reliable orientating tool. Concept: To look at a simple way to localize oneself, one should have a look at what has been done by mankind on Earth. Today, everyone can think of the GPS because it's simple and very reliable. However the infrastructure for such a system is huge and will not be for sure available during the first missions. We can think of course of a basic GPS using the satellites being in orbit but this approach is not yet as simple as we would like. If we want to keep the sky in sight, we can use the stars and the moons of Mars. Yet this would be a good solution and we can even have a star tracker that would give a good position according to the time of the picture. This solution has to be kept in mind but a star tracker is quite big for an astronaut without any rover nearby and using the sky may not be as precise as one should expect. Another useful tool is the compass. It has been used for centuries by sailors but on Mars, without a good magnetic field for this purpose. But sailors also use lighthouses and some placemarks on the land to localize themselves. This is done with a compass, measuring the angle between a placemark and the magnetic North. With two angles, we can then have the position of the boat. The idea here is the same: measuring the angles between different placemarks so that we can compute the position. But which placemarks? We have to think about something that can be installed on Mars and is light enough to be brought there. Balloons are really light, and in order to place them, we need a gas as helium (or hydrogen) and also some rope. Hydrogen is likely to be produced in situ and rope will be useful for astronauts. So we started on a concept with some balloons around the base, with different colors or patterns. The crew in EVA can thus know where the base is every time they are in sight of a balloon and with at least three balloons; they can compute their position according to the base. Procedure of the test: During EVA, the astronauts will measure the angle between the different balloons. The balloons are high in the sky so they can be seen far from their location. This is particularly important on Mars where the horizon is nearer than on Earth. The balloons have different colors so they can be identified and we can even think of adding an autonomous colored light under so they can be observed during the night. With good quality balloons, we can keep them in the sky for a few days without maintenance. Angle measurement is done thanks to a camera. A numeric camera can have a precision of less than 0.01°/pixel, which is enough for our application. The distance between the different balloons can easily be seen in a free picture management software and a Matlab tool is under development for this. An algorithm is then run and it gives the positions that fit with the observations on a map. Simulation gave areas 20m width, which is enough for the astronaut who has a map. The exact precision will be investigated in situ, at the MDRS. For this first test bench, computations will be manually done on a computer in order to validate the concept without huge development. Afterwards, one can imagine an implementation on a PDA brought by the astronauts. This PDA would have its own camera so the process can be fully automatic. Such a system can also implement other navigation system as a Martian GPS or a radio locali

Petitfils, E.-A.; Boche-Sauvan, L.; Foing, B. H.; Monaghan, E.; Crews, Eurogeomars

2009-04-01

228

Hybrid extended particle filter (HEPF) for integrated inertial navigation and global positioning systems  

NASA Astrophysics Data System (ADS)

Navigation includes the integration of methodologies and systems for estimating time-varying position, velocity and attitude of moving objects. Navigation incorporating the integrated inertial navigation system (INS) and global positioning system (GPS) generally requires extensive evaluations of nonlinear equations involving double integration. Currently, integrated navigation systems are commonly implemented using the extended Kalman filter (EKF). The EKF assumes a linearized process, measurement models and Gaussian noise distributions. These assumptions are unrealistic for highly nonlinear systems like land vehicle navigation and may cause filter divergence. A particle filter (PF) is developed to enhance integrated INS/GPS system performance as it can easily deal with nonlinearity and non-Gaussian noises. In this paper, a hybrid extended particle filter (HEPF) is developed as an alternative to the well-known EKF to achieve better navigation data accuracy for low-cost microelectromechanical system sensors. The results show that the HEPF performs better than the EKF during GPS outages, especially when simulated outages are located in periods with high vehicle dynamics.

Aggarwal, Priyanka; Syed, Zainab; El-Sheimy, Naser

2009-05-01

229

Development of a GPS-aided motion measurement, pointing, and stabilization system for a Synthetic Aperture Radar. [Global Positioning System (GPS)  

SciTech Connect

An advanced Synthetic Aperture Radar Motion Compensation System has been developed by Sandia National Laboratories (SNL). The system includes a miniaturized high accuracy ring laser gyro inertial measurement unit, a three axis gimbal pointing and stabilization assembly, a differential Global Positioning System (GPS) navigation aiding system, and a pilot guidance system. The system provides several improvements over previous SNL motion compensation systems and is capable of antenna stabilization to less than 0.01 degrees RMS and absolute position measurement to less than 5.0 meters RMS. These accuracies have been demonstrated in recent flight testing aboard a DHC-6-300 Twin Otter'' aircraft.

Fellerhoff, J.R.; Kohler, S.M.

1991-01-01

230

76 FR 33022 - Eighty-Sixth Meeting: RTCA Special Committee 159: Global Positioning System (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation Administration...159 meeting: Global Positioning System (GPS...Committee 159: Global Positioning System (GPS). DATES: The meeting will be held...

2011-06-07

231

75 FR 61818 - Eighty-Third Meeting: RTCA Special Committee 159: Global Positioning System (GPS).  

Federal Register 2010, 2011, 2012, 2013

...Committee 159: Global Positioning System (GPS). AGENCY: Federal Aviation Administration...159 meeting: Global Positioning System (GPS...Committee 159: Global Positioning System (GPS). DATES: The meeting will be held...

2010-10-06

232

76 FR 67019 - Eighty-Seventh: RTCA Special Committee 159: Global Positioning System (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation Administration...159 meeting: Global Positioning System (GPS...Committee 159: Global Positioning System (GPS) 87th meeting. DATES: The meeting...

2011-10-28

233

78 FR 13396 - 90th Meeting: RTCA Special Committee 159, Global Positioning Systems (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Committee 159, Global Positioning Systems (GPS) AGENCY: Federal Aviation Administration...Committee 159, Global Positioning Systems (GPS...Committee 159, Global Positioning Systems (GPS). DATES: The meeting will be held...

2013-02-27

234

76 FR 27744 - Eighty-Fifth Meeting: RTCA Special Committee 159: Global Positioning System (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation Administration...159 meeting: Global Positioning System (GPS...Committee 159: Global Positioning System (GPS). DATES: The meeting will be held...

2011-05-12

235

78 FR 57672 - 91st Meeting: RTCA Special Committee 159, Global Positioning Systems (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Committee 159, Global Positioning Systems (GPS) AGENCY: Federal Aviation Administration...Committee 159, Global Positioning Systems (GPS...Committee 159, Global Positioning Systems (GPS) DATES: The meeting will be held...

2013-09-19

236

77 FR 56254 - 89th Meeting: RTCA Special Committee 159, Global Positioning Systems (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Committee 159, Global Positioning Systems (GPS) AGENCY: Federal Aviation Administration...Committee 159, Global Positioning Systems (GPS...Committee 159, Global Positioning Systems (GPS). DATES: The meeting will be held...

2012-09-12

237

77 FR 12106 - 88th Meeting: RTCA Special Committee 159, Global Positioning System (GPS)  

Federal Register 2010, 2011, 2012, 2013

...Committee 159, Global Positioning System (GPS) AGENCY: Federal Aviation Administration...Committee 159, Global Positioning System (GPS...Committee 159, Global Positioning System (GPS). DATES: The meeting will be held...

2012-02-28

238

Theory of Inertial Navigation. Aided Systems.  

National Technical Information Service (NTIS)

Contents: Elements of the theory of autonomous inertial navigation systems; aided inertial systems: altimeter correction; Schuler-tuned gyropendulum systems, analogy with two-accelerometer inertial systems; Simplified operation equations of ideal and pert...

V. D. Andreev

1969-01-01

239

Inertially aided navigation system for an LHD  

Microsoft Academic Search

This paper describes the theoretical development and experimental evaluation of a guidance system for an autonomous load, haul and dump truck (LHD) for use in underground mining. The particular contributions of this paper are in designing the navigation system to be able to cope with vehicle slip in rough uneven terrain using information from an inertial navigation system (INS) and

S. Scheding; G. Dissanayake; E. Nebot; H. Durrant-Whyte

1996-01-01

240

Aircraft landing using GPS  

NASA Astrophysics Data System (ADS)

The advent of the Global Positioning System (GPS) is revolutionizing the field of navigation. Commercial aviation has been particularly influenced by this worldwide navigation system. From ground vehicle guidance to aircraft landing applications, GPS has the potential to impact many areas of aviation. GPS is already being used for non-precision approach guidance; current research focuses on its application to more critical regimes of flight. To this end, the following contributions were made: (1) Development of algorithms and a flexible software architecture capable of providing real-time position solutions accurate to the centimeter level with high integrity. This architecture was used to demonstrate 110 automatic landings of a Boeing 737. (2) Assessment of the navigation performance provided by two GPS-based landing systems developed at Stanford, the Integrity Beacon Landing System, and the Wide Area Augmentation System. (3) Preliminary evaluation of proposed enhancements to traditional techniques for GPS positioning, specifically, dual antenna positioning and pseudolite augmentation. (4) Introduction of a new concept for positioning using airport pseudolites. The results of this research are promising, showing that GPS-based systems can potentially meet even the stringent requirements of a Category III (zero visibility) landing system. Although technical and logistical hurdles still exist, it is likely that GPS will soon provide aircraft guidance in all phases of flight, including automatic landing, roll-out, and taxi.

Lawrence, David Gary

241

Navstar Global Positioning System \\/GPS\\/ clock program - Present and future  

Microsoft Academic Search

The success of the Global Positioning System (GPS) satellite program rests primarily on the reliability and performance of Cesium and Rubidium Atomic Frequency Standards and Crystal Oscillators. GPS can point with pride to two years of successful orbital experience with Rubidium and one year of Cesium. Program office activities and on-orbit performance over the last six months are summarized in

D. M. Tennant

1981-01-01

242

An Automatic Control System for Ratbot Navigation  

Microsoft Academic Search

In this paper, we present a novel intelligent control system for rat navigation based on video tracking and state machine techniques. And we demonstrate the automatic navigation of a rat to follow a preset course. The system consists of these components: (1) a wireless backpack stimulator comprised of stimulating circuit, control processor and bluetooth transceivers, (2) a video camera device

Yanming Zhang; Chao Sun; Nenggan Zheng; Shaomin Zhang; Jiyan Lin; Weidong Chen; Xiaoxiang Zheng

2010-01-01

243

Galileo: Impact on Spacecraft Navigation System  

Microsoft Academic Search

This article reviews the future impact of Galileo on spacecraft navigation systems. It outlines the Galileo benefits for spacecraft navigation systems, including the number of available frequencies and services, up to 3 separated frequencies for one service; application of the Three Carrier Ambiguity Resolution (TCAR) technique for substantial improved spacecraft attitude determination algorithms; high data rates for improved signal acquisition

Werner Enderle

244

A New Visualization Concept for Navigation Systems  

Microsoft Academic Search

At present, various types of car navigation systems are progressively entering the market. Simultaneously, mobile outdoor navigation systems for pe- destrians and electronic tourist guides are already available on handheld com- puters. Although, the depiction of the geographical information on these appli- ances has increasingly improved during the past years, users are still handicapped having to interpret an abstract metaphor

Wolfgang Narzt; Gustav Pomberger; Alois Ferscha; Dieter Kolb; Reiner Müller; Jan Wieghardt; Horst Hörtner; Christopher Lindinger

2004-01-01

245

Overview: Navigation Systems Analysis Methods and Procedures.  

National Technical Information Service (NTIS)

The purpose this paper is to provide an overview of the inland navigation systems analysis procedures which are being used in the Ohio River Division (ORD). The responsibility for system studies in ORD has been assigned to newly formed navigation planning...

R. Keeney

1982-01-01

246

Clear skies ahead [navigation systems  

Microsoft Academic Search

Several projects aimed squarely at upgrading airplane travel, either by enhancing navigation or by improving communications between pilots and air traffic controllers, drew closer to full implementation in 2001. In mid-June, the US Federal Aviation Administration (FAA), Washington, DC, outlined its 10-year operational evolution plan to improve air travel by rolling out new technology to air traffic control facilities. All

E. A. Bretz

2002-01-01

247

A Wearable Computer System with Augmented Reality to Support Terrestrial Navigation  

Microsoft Academic Search

To date augmented realities are typically operated in only a small defined area, in the order of a large room. This paper reports on our investigation into expanding augmented realities to outdoor environments. The project entails providing visual navigation aids to users. A wearable computer system with a see-through display, digital compass, and a differential GPS are used to provide

Bruce H. Thomas; Victor Demczuk; Wayne Piekarski; David Hepworth; Bernard K. Gunther

1998-01-01

248

Current status and future of the US Navy satellite navigation system  

Microsoft Academic Search

The status and future of the US Navy Transit satellite system for maritime navigation are reviewed in the light of its planned replacement by Navstar GPS. The Oscar, Nova, and SOOS satellites; their orbits and performance parameters; the Scout launcher; the tracking network; and the correction procedures for ionospheric refraction are characterized and illustrated with drawings, diagrams, and graphs. Current

G. W. Hoskins; R. J. Danchik

1984-01-01

249

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

USGS Publications Warehouse

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.

Sanchez, Richard D.; Hothem, Larry D.

2002-01-01

250

Gravity aided inertial navigation system (GAINS)  

NASA Astrophysics Data System (ADS)

The paper describes a new autonomous covert INS uniquely suited to underwater applications. Unlike the conventional INS, schuler and siderial errors are bounded without external navigation aids or active instrumentation of ground speed. As a result, the system exhibits excellent long-term navigation performance while maintaining the inherent covertness of the INS system. A conventional INS is integrated with a gravity gradiometer capable of measuring gravity field components independently of platform accelerations. This new integration scheme takes advantage of navigation system velocity error observability. Parametric performance results are presented for GAINS, varying gyro, gravimeter, gradiometer, depth sensor quality, and gravity field activity.

Jircitano, Albert; Dosch, Daniel E.

251

The transmission link of CAPS navigation and communication system  

NASA Astrophysics Data System (ADS)

The Chinese Area Positioning System (CAPS) is based on communication satellites with integrated capability, which is different from the Global Positioning System (GPS), the International Maritime Satellite Organization (Inmarsat) and so on. CAPS works at C-band, and its navigation information is not directly generated from the satellite, but from the master control station on the ground and transmitted to users via the satellite. The slightly inclined geostationary-satellite orbit (SIGSO) satellites are adopted in CAPS. All of these increase the difficulty in the design of the system and terminals. In this paper, the authors study the CAPS configuration parameters of the navigation master control station, information transmission capability, and the selection of the antenna aperture of the communication center station, as well as the impact of satellite parameters on the whole communication system from the perspective of the transmission link budget. The conclusion of availability of the CAPS navigation system is achieved. The results show that the CAPS inbound communication system forms a new low-data-rate satellite communication system, which can accommodate mass communication terminals with the transmission rate of no more than 1 kbps for every terminal. The communication center station should be configured with a large-aperture antenna (about 10-15 m); spread spectrum communication technology should be used with the spreading gain as high as about 40 dB; reduction of the satellite transponder gain attenuation is beneficial to improving the signal-to-noise ratio of the system, with the attenuation value of 0 or 2 dB as the best choice. The fact that the CAPS navigation system has been checked and accepted by the experts and the operation is stable till now clarifies the rationality of the analysis results. The fact that a variety of experiments and applications of the satellite communication system designed according to the findings in this paper have been successfully carried out confirms the correctness of the study results.

Cui, Junxia; Shi, Huli; Chen, Jibin; Pei, Jun

2009-03-01

252

NTNU Java: How GPS works  

NSDL National Science Digital Library

This applet describes and demonstrates how GPS works. The Global Positioning System (GPS) is actually a constellation of 27 Earth-orbiting satellites (24 in operation and three extras in case one fails)implemented by the U.S. military for military navigation.

Hwang, Fu-Kwun

2008-07-07

253

One Approach to Ballistic-Navigation Design of an Advanced Space Navigation System  

NASA Astrophysics Data System (ADS)

Initial preconditions for solving the problem of ballistic-navigation design of a future-technology space navigation system (SNS) are presented. A technical approach to the SNS design is proposed, whose basis is theoretical results in the field of space navigation applied to the orbital satellite groups, generating the global radio navigation field (RNF) with optimum navigation properties. The mathematical apparatus adequate to the proposed technical approach is introduced to analyze the structure of the orbital group and radio navigation field.

Braslavets, R. I.

2001-01-01

254

Interoperability of satellite-based augmentation systems for aircraft navigation  

NASA Astrophysics Data System (ADS)

The Federal Aviation Administration (FAA) is pioneering a transformation of the national airspace system from its present ground based navigation and landing systems to a satellite based system using the Global Positioning System (GPS). To meet the critical safety-of-life aviation positioning requirements, a Satellite-Based Augmentation System (SBAS), the Wide Area Augmentation System (WAAS), is being implemented to support navigation for all phases of flight, including Category I precision approach. The system is designed to be used as a primary means of navigation, capable of meeting the Required Navigation Performance (RNP), and therefore must satisfy the accuracy, integrity, continuity and availability requirements. In recent years there has been international acceptance of Global Navigation Satellite Systems (GNSS), spurring widespread growth in the independent development of SBASs. Besides the FAA's WAAS, the European Geostationary Navigation Overlay Service System (EGNOS) and the Japan Civil Aviation Bureau's MTSAT-Satellite Augmentation System (MSAS) are also being actively developed. Although all of these SBASs can operate as stand-alone, regional systems, there is increasing interest in linking these SBASs together to reduce costs while improving service coverage. This research investigated the coverage and availability improvements due to cooperative efforts among regional SBAS networks. The primary goal was to identify the optimal interoperation strategies in terms of performance, complexity and practicality. The core algorithms associated with the most promising concepts were developed and demonstrated. Experimental verification of the most promising concepts was conducted using data collected from a joint international test between the National Satellite Test Bed (NSTB) and the EGNOS System Test Bed (ESTB). This research clearly shows that a simple switch between SBASs made by the airborne equipment is the most effective choice for achieving the desired interoperability. It yields at least 95% of the availability benefit achievable with a much more expensive optimal solution. Other more complex scenarios generally do not provide greater benefit, and create greater algorithm complexity and typically have significant infrastructure cost increases. Therefore, the airborne switching approach is highly recommended and should be adopted as the interoperability standard.

Dai, Donghai

255

Report on GPS and Galileo Time Offset Coordination Efforts.  

National Technical Information Service (NTIS)

Precise timing is an inherent part of Radio Navigation Systems like GPS and Galileo. This paper will update progress on cooperative efforts between the GPS system and the Galileo system to harmonize the underlying Navigation time scales of both systems to...

E. D. Powers J. H. Hahn

2007-01-01

256

Satellite Navigation Systems in the Transport, Today and in the Future  

NASA Astrophysics Data System (ADS)

Operational status and practical exploitation (October 2010) of Satellite Navigation Systems (SNS), as GPS and GLONASS, and Satellite Based Augmentation System (SBAS), as EGNOS are presented in this paper. Other SNS are under development as Galileo and Compass, other SBAS in various part of the world are already available (WAAS, MSAS) or under development as GAGAN or SDCM. The receivers of these systems are now found in every mode of transportation - air, maritime and land. Additionally SNS markets and applications in the transport and the most significant events in the satellite navigation systems in the nearest years and SNS markets and applications are described also.

Januszewski, Jacek

2010-01-01

257

The CMU system for mobile robot navigation  

Microsoft Academic Search

This paper describes the current status of the Autonomous Land Vehicle research at Carnegie-Mellon University's Robotics Institute, focusing primarily on the system architecture. We begin with a discussion of the issues concerning outdoor navigation, then describe the various perception, planning, and control components of our system that address these issues. We describe the CODGER software system for integrating these components

Yoshimasa Goto; Anthony Stentz

1987-01-01

258

Enhancing outdoor navigation systems through vibrotactile feedback  

Microsoft Academic Search

While driving many tasks compete for the attention of the user, mainly via the audio and visual channel. When designing systems depending upon providing feedback to users (e.g., navigation systems), it is a crucial prerequisite to minimize influence on and distraction from the driving task. This becomes even more important when designing systems for the use on motorbikes; space for

Dominik Bial; Dagmar Kern; Florian Alt; Albrecht Schmidt

2011-01-01

259

Advanced Development of ESG Strapdown Navigation Systems  

Microsoft Academic Search

The fundamental problem of inertial navigation, double integration of acceleration to obtain position, is defined and discussed. Mechanizations of both space-stable and local-vertical platform systems are exhibited. The synthesis problem for an electrically suspended gyro (ESG) strapdown system is defined and discussed: readout, readout errors due to vehicle motion, synchronization of readout with system computer, alignment, correction and calibration for

T. W. Christensen

1966-01-01

260

Navigation of robotic system using cricket motes  

NASA Astrophysics Data System (ADS)

This paper presents a novel algorithm for self-mapping of the cricket motes that can be used for indoor navigation of autonomous robotic systems. The cricket system is a wireless sensor network that can provide indoor localization service to its user via acoustic ranging techniques. The behavior of the ultrasonic transducer on the cricket mote is studied and the regions where satisfactorily distance measurements can be obtained are recorded. Placing the motes in these regions results fine-grain mapping of the cricket motes. Trilateration is used to obtain a rigid coordinate system, but is insufficient if the network is to be used for navigation. A modified SLAM algorithm is applied to overcome the shortcomings of trilateration. Finally, the self-mapped cricket motes can be used for navigation of autonomous robotic systems in an indoor location.

Patil, Yogendra J.; Baine, Nicholas A.; Rattan, Kuldip S.

2011-05-01

261

Navigation in Antarctica Today: The Global Positioning System  

NSDL National Science Digital Library

After researching how the Global Positioning System is used in Antarctica and across the globe, students learn how GPS works. Throughout this weeklong activity, students collect their findings in a portfolio. The comprehensive curriculum materials contain teacher tools, which include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, and additional readings. Students investigate the use of the Global Positioning System (GPS)in Antarctica and across the globe. They conduct research on the Web to understand how and why GPS is used today. Students also complete a hands-on activity that is based on spatial principles similar to those used by GPS; they learn how GPS works by doing on paper the work of GPS satellites in space.

262

Integrated Multi-Aperture Sensor and Navigation Fusion.  

National Technical Information Service (NTIS)

The integration of vision sensors and inertial navigation system (INS) can enable precision navigation capabilities in the absence of GPS. Inspired from biological systems, a multi-aperture vision processing system allows for accurate self-motion (egomoti...

A. Rutkowski A. Soloviev J. Touma M. Miller T. Klausutis

2010-01-01

263

Navigation based on symbolic space models  

Microsoft Academic Search

Existing navigation systems are very appropriate for car navigation, but lack support for convenient pedestrian navigation and cannot be used indoors due to GPS limitations. In addition, the creation and the maintenance of the required models are costly and time consuming, and are usually based on proprietary data structures. In this paper we describe a navigation system based on a

Karolina Baras; A. Moreira; F. Meneses

2010-01-01

264

Inertial navigation system for mobile land vehicles  

Microsoft Academic Search

This paper describes a prototype of an inertial navigation system for use in mobile land vehicles, such as cars or mobile robots. The complete system is composed by sensors, their mechanical mount and cabling, these connect to a PC card with local processing and memory, based on a Intel 80C196KC microcontroller. The sensors used were a piezoelectric vibrating gyroscope, two

Jorge Lobo; Paulo Lucas; Jorge Dias; A. Traca de Almeida

1995-01-01

265

Fault tolerant integrated inertial navigation\\/global positioning systems for next generation spacecraft  

Microsoft Academic Search

The authors address the requirements, benefits, and mitigation of risks to adapt a commercial Hexad fault-tolerant inertial navigation\\/global positioning system (FT IN\\/GPS) for use in next-generation spacecraft. Next-generation requirements are examined to determine whether a high production base system can meet autonomous, reliable, and low-cost requirements for future spacecraft. The major benefits are the combining and replacement of functions, the

Hugh Miller; David A. Hilts

1991-01-01

266

Use of Global Positioning System (GPS) receivers under power-line conductors  

Microsoft Academic Search

The use of Global Positioning System (GPS) technology continues to grow and accuracy augmentations will generate ever more innovative applications. The issue of GPS use under or near electric power lines has been raised since some GPS documents have vague warnings about such use. First, GPS and the satellite microwave signals used to determine position, velocity, and time are described.

J. Michael Silva; Robert G. Olsen

2002-01-01

267

The International GPS Service: Celebrating the 10th anniversary and looking to the next decade  

Microsoft Academic Search

After 10 years as a service of the International Association of Geodesy, the International GPS Service IGS is preparing for the future use of multiple integrated global navigation satellite systems: GPS and its modernisation, Galileo and GLONASS. Since 1994, the IGS produces GPS data and products at the highest level of precision and accuracy available anywhere: it provides GPS orbits

J. M. Dow; R. E. Neilan; G. Gendt

2005-01-01

268

Sensing the Earth using Global Navigation Satellite System signals  

NASA Astrophysics Data System (ADS)

International Workshop on GNSS Remote Sensing for Future Missions and Sciences; Shanghai, China, 7-9 August 2011 The Global Navigation Satellite System (GNSS) has been widely used in navigation, positioning, and geoscience applications. Recently, the versatility of GNSS as a new remote sensing tool has been demonstrated with the use of refracted, reflected, and scattered GNSS signals to sound the atmosphere and ionosphere, ocean, land surfaces (including soil moisture), and cryosphere. Existing GPS radio occultation (RO) missions—e.g., the U.S.-Argentina SAC-C, German Challenging Minisatellite Payload (CHAMP), U.S.-Germany Gravity Recovery and Climate Experiment (GRACE), Taiwan-U.S. Formosa Satellite Mission-3/Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT-3/COSMIC) satellites, German TerraSAR-X satellite, and European MetOp—together with groundbased GNSS observations, have provided precise and high-resolution information on tropospheric water vapor, pressure, temperature, tropopause parameters, ionospheric total electron content, and electron density profiles. GNSS signals reflected from the ocean and land surface can determine the ocean height, ocean surface wind speed and wind direction, soil moisture, and ice and snow thickness. With improvement expected due to the next generation of multifrequency GNSS systems and receivers, and new space-based instruments tracking GNSS reflected and refracted signals, new scientific applications of GNSS are expected in the near future across a number of environmental remote sensing fields.

Jin, Shuanggen; Rizos, Chris; Rius, Antonio

2011-11-01

269

Obstacle-avoiding navigation system  

DOEpatents

A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

Borenstein, Johann (Ann Arbor, MI); Koren, Yoram (Ann Arbor, MI); Levine, Simon P. (Ann Arbor, MI)

1991-01-01

270

INFORMATISATION OF TRANSPORT PROCESS USING GPS NAVIGATION SYSTEM  

Microsoft Academic Search

Nowadays, internal business processes are one of the crucial factors of firms' competitive advantage achievement, which is becoming increasingly important, not only on local but also on global markets. Firms' performance improvement depends to a large extent on its flexibility, adjustability and especially ability to manage internal business processes. Hence, use of information technology is among the fundamental elements of

Andreja Habjan; Costas Andriopoulos

2009-01-01

271

Exploitation of Semantic Building Model in Indoor Navigation Systems  

NASA Astrophysics Data System (ADS)

There are many types of indoor and outdoor navigation tools and methodologies available. A majority of these solutions are based on Global Positioning Systems (GPS) and instant video and image processing. These approaches are ideal for open world environments where very few information about the target location is available, but for large scale building environments such as hospitals, governmental offices, etc the end-user will need more detailed information about the surrounding context which is especially important in case of people with special needs. This paper presents a smart indoor navigation solution that is based on Semantic Web technologies and Building Information Model (BIM). The proposed solution is also aligned with Google Android's concepts to enlighten the realization of results. Keywords: IAI IFCXML, Building Information Model, Indoor Navigation, Semantic Web, Google Android, People with Special Needs 1 Introduction Built environment is a central factor in our daily life and a big portion of human life is spent inside buildings. Traditionally the buildings are documented using building maps and plans by utilization of IT tools such as computer-aided design (CAD) applications. Documenting the maps in an electronic way is already pervasive but CAD drawings do not suffice the requirements regarding effective building models that can be shared with other building-related applications such as indoor navigation systems. The navigation in built environment is not a new issue, however with the advances in emerging technologies like GPS, mobile and networked environments, and Semantic Web new solutions have been suggested to enrich the traditional building maps and convert them to smart information resources that can be reused in other applications and improve the interpretability with building inhabitants and building visitors. Other important issues that should be addressed in building navigation scenarios are location tagging and end-user communication. The available solutions for location tagging are mostly based on proximity sensors and the information are bound to sensor references. In the proposed solution of this paper, the sensors simply play a role similar to annotations in Semantic Web world. Hence the sensors data in ontology sense bridges the gap between sensed information and building model. Combining these two and applying the proper inference rules, the building visitors will be able to reach their destinations with instant support of their communication devices such as hand helds, wearable computers, mobiles, etc. In a typical scenario of this kind, user's profile will be delivered to the smart building (via building ad-hoc services) and the appropriate route for user will be calculated and delivered to user's end-device. The calculated route is calculated by considering all constraints and requirements of the end user. So for example if the user is using a wheelchair, the calculated route should not contain stairs or narrow corridors that the wheelchair does not pass through. Then user starts to navigate through building by following the instructions of the end-device which are in turn generated from the calculated route. During the navigation process, the end-device should also interact with the smart building to sense the locations by reading the surrounding tags. So for example when a visually impaired person arrives at an unknown space, the tags will be sensed and the relevant information will be delivered to user in the proper way of communication. For example the building model can be used to generate a voice message for a blind person about a space and tell him/her that "the space has 3 doors, and the door on the left should be chosen which needs to be pushed to open". In this paper we will mainly focus on automatic generation of semantic building information models (Semantic BIM) and delivery of results to the end user. Combining the building information model with the environment and user constraints using Semantic Web technologies will make many scenarios conceivable. The gen

Anjomshoaa, A.; Shayeganfar, F.; Tjoa, A. Min

2009-04-01

272

A global positioning system (GPS) interference electronics support measure (ESM) payload system for unmanned aerial vehicles (UAVs)  

NASA Astrophysics Data System (ADS)

Modern battlefields depend on GPS for precision navigation and timing. Unfortunately, GPS signals are very-low level and GPS interference, both intentional and unintentional, can severely degrade GPS performance. Unmanned Aerial Vehicles (UAV), which have proven their value on the battlefield, rely heavily on GPS for navigation and flight integrity. Key to continued mission success for UAVs is enhanced anti-jamming capabilities. A revealing test of anti-jamming performance for a UAV is to maintain GPS synchronization, while accurately locating a GPS jammer. A small, modular ESM payload is needed to supply anti-jamming performance for the UAV and secondarily, to use DF techniques to locate the GPS jammer. This paper investigates a small, low-power, low-cost, modular solution to reducing the vulnerability to jamming of UAVs by leveraging commercial off-the-shelf technology. A miniaturized GPS antenna configuration that both lowers susceptibility to GPS jamming, and also allows accurate determination of the GPS jammer"s location, is presented. This GPS antenna arrangement consists of two GPS antenna arrays, one positioned on the top of the UAV (facing skyward) and one positioned on the underside of the UAV (facing the ground). The top antenna array acquires and tracks a minimum of 4 GPS satellites for accurate positioning and timing. The bottom antenna array is used to detect and locate GPS interference, and in coordination with the top array, limits susceptibility to GPS interference. The first action upon detecting GPS interference is to alter the reception pattern of the top GPS antenna array to reduce the amount of interference processed by the GPS receiver. Simultaneously, sampled data from both antenna arrays are used to monitor the effect of the interference and calculate the position of the jammer.

Wurth, Timothy J.; Wells, Jeffrey S.

2004-09-01

273

GPS Bibliography by the National Geodetic Survey  

NSDL National Science Digital Library

This bibliography, intended for more advanced users, is a compilation of peer-reviewed articles published in 2006 describing original research with citations on Global Positioning Systems (GPS) and Global Satellite Navigation Systems (GNSS).

2010-11-24

274

A programmable FPGA implementation of a multi-coded BOC(m,n) signal generator for navigation systems  

Microsoft Academic Search

A new signal will be used within the modernized satellites for the global positioning system (GPS) as well as within the launch of the new European global navigation satellite system (GNSS) called Galileo, this signal will use the binary offset carrier (BOC) modulation scheme. BOC signals have very attractive features such as better tracking and immunity to multipath, as well

Mohammad S. Sharawi; Daniel N. Aloi

2008-01-01

275

Investigation of GPS/IMU Positioning System for Mining Equipment  

SciTech Connect

The objective of this project is to investigate the applicability of a combined Global Positioning System and Inertial Measurement Unit (GPS/IMU) for information based displays on earthmoving machines and for automated earthmoving machines in the future. This technology has the potential of allowing an information-based product like Caterpillar's Computer Aided Earthmoving System (CAES) to operate in areas with satellite shading. Satellite shading is an issue in open pit mining because machines are routinely required to operate close to high walls, which reduces significantly the amount of the visible sky to the GPS antenna mounted on the machine. An inertial measurement unit is a product, which provides data for the calculation of position based on sensing accelerations and rotation rates of the machine's rigid body. When this information is coupled with GPS it results in a positioning system that can maintain positioning capability during time periods of shading.

Ken L. Stratton

2006-09-13

276

Multiposition alignment of strapdown inertial navigation system  

Microsoft Academic Search

The authors demonstrate that the stationary alignment of strapdown inertial navigation system (SDINS) can be improved by employing the multiposition\\/technique. Using an observability analysis, it is shown that an optimal two-position alignment not only satisfies complete observability conditions but also minimizes alignment errors. This is done by analytic rank testing of the stripped observability matrix and numerical calculation of the

J. G. Lee; C. G. Park; H. W. Park

1993-01-01

277

Design of gyroscope-free navigation systems  

Microsoft Academic Search

We examine the feasibility of designing a gyroscope-free inertial navigation system (INS) that uses only accelerometers to compute the linear and angular motions of a rigid body. The accelerometer output equation is derived to relate the linear and angular motions of a rigid body relative to a fixed inertial frame. A sufficient condition is given to determine if a configuration

Chin-Woo Tan; K. Mostov; P. Varaiya

2001-01-01

278

Localizability Analysis for GPS\\/Galileo Receiver Autonomous Integrity Monitoring  

Microsoft Academic Search

With the European Commission (EC) and European Space Agency's (ESA) plans to develop a new satellite navigation system, Galileo and the modernisation of GPS well underway the integrity of such systems is as much, if not more, of a concern as ever. Receiver Autonomous Integrity Monitoring (RAIM) refers to the integrity monitoring of the GPS\\/Galileo navigation signals autonomously performed by

Steve Hewitson; Hung Kyu Lee; Jinling Wang

2004-01-01

279

Site Selection Plan and Installation Guidelines for a Nationwide Differential GPS Service.  

National Technical Information Service (NTIS)

The Global Positioning System (GPS), in its current form, is used within the transportation industry for vehicle tracking and navigation. With the advent of a nationwide differential GPS (DGPS) service, this role will expand to include public safety, infr...

R. L. Ketchum J. J. Lemmon J. R. Hoffman

1997-01-01

280

Relative Navigation Requirements for Automatic Rendezvous and Capture Systems.  

National Technical Information Service (NTIS)

This paper will discuss in detail the relative navigation system requirements and sensor trade-offs for Automatic Rendezvous and Capture. Rendezvous navigation filter development will be discussed in the context of navigation performance requirements for ...

P. M. Kachmar R. J. Polutchko W. Chu M. Montez

1991-01-01

281

Comparative Analysis of Optimized Signals for Satellite Navigation Systems  

Microsoft Academic Search

Abstract— Recently the Multiplexed Binary Offset Carrier (MBOC) has been proposed as a possible modulation with improved performance for the future signals to be broadcast bythe Global Positioning System (GPS) and Galileo. Such a proposed signal will be adopted by the GPS L1C and the Galileo E1 Open Service (OS) signals [1]. The MBOC power spectral density isa mixtu re

Fabio Dovis; Letizia Lo Presti

282

A comparison between different error modeling of MEMS applied to GPS/INS integrated systems.  

PubMed

Advances in the development of micro-electromechanical systems (MEMS) have made possible the fabrication of cheap and small dimension accelerometers and gyroscopes, which are being used in many applications where the global positioning system (GPS) and the inertial navigation system (INS) integration is carried out, i.e., identifying track defects, terrestrial and pedestrian navigation, unmanned aerial vehicles (UAVs), stabilization of many platforms, etc. Although these MEMS sensors are low-cost, they present different errors, which degrade the accuracy of the navigation systems in a short period of time. Therefore, a suitable modeling of these errors is necessary in order to minimize them and, consequently, improve the system performance. In this work, the most used techniques currently to analyze the stochastic errors that affect these sensors are shown and compared: we examine in detail the autocorrelation, the Allan variance (AV) and the power spectral density (PSD) techniques. Subsequently, an analysis and modeling of the inertial sensors, which combines autoregressive (AR) filters and wavelet de-noising, is also achieved. Since a low-cost INS (MEMS grade) presents error sources with short-term (high-frequency) and long-term (low-frequency) components, we introduce a method that compensates for these error terms by doing a complete analysis of Allan variance, wavelet de-nosing and the selection of the level of decomposition for a suitable combination between these techniques. Eventually, in order to assess the stochastic models obtained with these techniques, the Extended Kalman Filter (EKF) of a loosely-coupled GPS/INS integration strategy is augmented with different states. Results show a comparison between the proposed method and the traditional sensor error models under GPS signal blockages using real data collected in urban roadways. PMID:23887084

Quinchia, Alex G; Falco, Gianluca; Falletti, Emanuela; Dovis, Fabio; Ferrer, Carles

2013-07-24

283

A Comparison between Different Error Modeling of MEMS Applied to GPS/INS Integrated Systems  

PubMed Central

Advances in the development of micro-electromechanical systems (MEMS) have made possible the fabrication of cheap and small dimension accelerometers and gyroscopes, which are being used in many applications where the global positioning system (GPS) and the inertial navigation system (INS) integration is carried out, i.e., identifying track defects, terrestrial and pedestrian navigation, unmanned aerial vehicles (UAVs), stabilization of many platforms, etc. Although these MEMS sensors are low-cost, they present different errors, which degrade the accuracy of the navigation systems in a short period of time. Therefore, a suitable modeling of these errors is necessary in order to minimize them and, consequently, improve the system performance. In this work, the most used techniques currently to analyze the stochastic errors that affect these sensors are shown and compared: we examine in detail the autocorrelation, the Allan variance (AV) and the power spectral density (PSD) techniques. Subsequently, an analysis and modeling of the inertial sensors, which combines autoregressive (AR) filters and wavelet de-noising, is also achieved. Since a low-cost INS (MEMS grade) presents error sources with short-term (high-frequency) and long-term (low-frequency) components, we introduce a method that compensates for these error terms by doing a complete analysis of Allan variance, wavelet de-nosing and the selection of the level of decomposition for a suitable combination between these techniques. Eventually, in order to assess the stochastic models obtained with these techniques, the Extended Kalman Filter (EKF) of a loosely-coupled GPS/INS integration strategy is augmented with different states. Results show a comparison between the proposed method and the traditional sensor error models under GPS signal blockages using real data collected in urban roadways.

Quinchia, Alex G.; Falco, Gianluca; Falletti, Emanuela; Dovis, Fabio; Ferrer, Carles

2013-01-01

284

MECHANIZED IRRIGATION SYSTEM POSITIONING USING TWO INEXPENSIVE GPS RECEIVERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Precision irrigation or chemigation using mechanized irrigation systems such as center pivots or lateral moves requires accurate and real-time knowledge of the irrigation system's field location. A GPS receiver mounted on a center pivot or lateral move has the potential to increase the accuracy of ...

285

Investigation of GPS\\/IMU Positioning System for Mining Equipment  

Microsoft Academic Search

The objective of this project is to investigate the applicability of a combined Global Positioning System and Inertial Measurement Unit (GPS\\/IMU) for information based displays on earthmoving machines and for automated earthmoving machines in the future. This technology has the potential of allowing an information-based product like Caterpillar's Computer Aided Earthmoving System (CAES) to operate in areas with satellite shading.

Ken L. Stratton

2006-01-01

286

Satellite Navigation Systems: Policy, Commercial and Technical Interaction.  

NASA Astrophysics Data System (ADS)

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

Rycroft, M.

2003-12-01

287

Impact of New Navigation Support System for Mariners  

Microsoft Academic Search

Development of navigation support system was important for the safety navigation. However, it was also important to evaluate the influence of a new navigation support system on mariners for the safe maneuvering. In this research, ship maneuvering simulation experiment was executed to examine the impact of a new navigation support system and subject's response and performance in the experiment were

Tadatsugi Okazaki; J. Fukuto

2006-01-01

288

Waypoint Navigation for Rivercraft?  

NASA Astrophysics Data System (ADS)

Anticipating that transport on the West European inland waterways will increase in volume, in ship size and in speed, experiments are being carried out to investigate whether safety of navigation - including traffic management - can be improved by the employment of GPS or DGPS, electronic navigation charts, river radar and computer technology. Although waypoint navigation and collision avoidance systems are generally accepted in the maritime world, these methods could cause problems when applied on inland waterways.

Breedveld, D.

289

GPS Tutorial by Trimble  

NSDL National Science Digital Library

This animated tutorial introduces users to Global Positioning Systems (GPS) technology. Topics include what GPS is, how it works, timing, satellite error, differential GPS, and how to use GPS. There is also a glossary.

2010-08-12

290

Theoretical Aspects of the Ballistic-Navigation Design of an Advanced Space Navigation System  

NASA Astrophysics Data System (ADS)

The capability of an orbital constellation to generate a global radio navigation field (RNF) of perfect quality is theoretically analyzed. The optimum geometrical network formed on the orbital sphere is the basis of this analysis. We invoke a criterial apparatus for estimating the ballistic-navigation characteristics of an orbital constellation and its elements, as well as specific navigation properties of an RNF. The numerical data concerning some structural parameters of orbital constellations are obtained for existing and advanced space navigation systems (SNS).

Braslavets, R. I.

2002-09-01

291

Velocity and position error compensation using strapdown inertial navigation system\\/celestial navigation system integration based on ensemble neural network  

Microsoft Academic Search

Strapdown inertial navigation system (SINS)\\/celestial navigation system (CNS) integrated navigation system can estimate attitude errors and gyro drift. However, prior to star sensor working, initial misalignments and accelerometer bias may cause large velocity and position errors which cannot be estimated by using CNS. Therefore, this paper aims to find an effective solution that can estimate and correct for the navigation

Fan Xu; Jiancheng Fang

2008-01-01

292

A GPS Real Time Earthquake and Tsunami (GREAT) Alert System  

NASA Astrophysics Data System (ADS)

The GREAT Alert is a NASA-sponsored, real-time prototype system designed to enhance natural hazard warning capability and damage assessment. The system takes advantage of the increasingly available global and regional real-time GPS data, as well as advanced fault and ocean dynamics models to enable more accurate and timely assessment of the magnitude and mechanism of large earthquakes, and the magnitude and direction of resulting tsunamis. We will describe the prototype operational system being developed, highlighting the underlying GNSS technology. The key system components are: 1. The operational real-time estimation of site coordinates from hundreds of GPS sites using a precise point positioning (PPP) algorithm. This is accomplished by the NASA Global Differential GPS (GDGPS) System which, unlike other GPS algorithms such as real-time kinematic (RTK), is insensitive to motions of any ground-based reference stations in the vicinity of an event. 2. The application of data filtering and quality control techniques to the real-time site position time series in order to enhance the accurate retrieval of co-seismic site motions. 3. Usage of a Fingerprint inversion model (and potentially other models) for the rapid determination of the earthquake displacement field from the GPS-based records of ground motion at each station. 4. Detected and modeled seafloor displacements are then used within a special ocean dynamics model to determine tsunami source energy and scales, and estimate the tsunami propagation. 5. The resulting near-real-time information about earthquake source properties magnitude, type, and when relevant, magnitude and direction of the resulting tsunami, is then available to the responsible agencies to help in their decision-making processes. We will discuss the preliminary performance of the system, and analyze the aspects of GNSS infrastructure and technology that require further investments in order to realize the full potential of the GREAT Alert system and similar approaches for natural hazard monitoring.

Bar-Sever, Yoaz

2010-05-01

293

On intelligent transportation system based on GPS and data mining  

Microsoft Academic Search

On the basis of the effective using of the satellite information offered by GPS, this paper sets up the database of the real-time information of traffic conditions that combined road information acquired by various types of vehicles in ITS and exploit data mining software of analytical work, construct the more advanced intellectual traffic system of city in order to help

Yan Bo; Huang Yehua; Ma Xinjun

2008-01-01

294

Formations of autonomous vehicles using Global Positioning Systems (GPS)  

Microsoft Academic Search

In this work we present the design, development, and testing of a hardware testbed for formation movement, using a fleet of autonomous R\\/C (remote control) vehicles equipped with Global Positioning Systems (GPS). The work was formulated and executed as a student project with the intent of being both a vehicle for education and investigation into low-cost formation control. The low

Kourosh Rahnamai; Kevin Gorman; Andrew Gray; Payman Arabshahi

2005-01-01

295

Methodology Investigation, Final Report of Global Positioning System Integration (GPS).  

National Technical Information Service (NTIS)

Testing at U.S. Army Aviation Technical Test Center (ATTC), Fort Rucker, Alabama, requires nap-of-the-earth time space position information (TSPI) of rotary-wing aircraft integrated with other aircraft parameters. The Global Positioning System (GPS), inte...

L. K. Martin

1993-01-01

296

ICBM reentry vehicle navigation system development at Honeywell  

Microsoft Academic Search

Development of navigation systems for reentry vehicles launched by ICBMs was initiated at Honeywell in 1977. Maintaining an accurate navigation solution through the spinning coast phase, and high acceleration reentry phase, of a reentry vehicle (RV) flight was enabled by the development of the Ring Laser Gyro. The original product, the Dormant Inertial Navigation System (DINS), provided navigation for the

J. Boutelle; S. P. Kau

1998-01-01

297

A multiagent system for maritime navigation simulation  

Microsoft Academic Search

The paper introduces the principles underlying the TRANS prototype, a multi-agent system oriented to concurrent maritime navigations. TRANS integrates several multi-agent modelling notions such as role and group behaviours, it extends those to the concepts of permanent and temporary roles and allows for priority and constraint management. Agents model either mobile entities or static geographical references. Mobile agents, i.e., ships

S. Fournier

2005-01-01

298

Integrating External Position Information with GPS using Existing GPS Processing Software for Precision Agriculture Applications  

Microsoft Academic Search

The Integration of GPS with additional position technologies, such as Inertial Navigation Systems (INS), is an area of research that is well developed. The complimentary properties of the two systems, the long term stability and accuracy of GPS with the reliability and high data rates of the INS system, have meant they have been ideal candidates for integration in order

Anthony Cole

299

Accessible Global Positioning System (GPS) and Related Orientation Technologies  

Microsoft Academic Search

\\u000a One of the better-developed technologies for pinpointing a person’s location is the global positioning system (GPS). This\\u000a US positioning technology has been widely exploited in many consumer applications and over future years alternative systems\\u000a will become available for use (notably the European Galileo system). The success of a system for use by the visually impaired\\u000a will depend on the accessibility

Michael May; Charles LaPierre

300

Cascade Kalman filter application in GPSINS integrated navigation for car like robot  

Microsoft Academic Search

Global Positioning System (GPS) is a common choice for positioning in Land vehicle navigation system technology. However, GPS alone is incapable of providing continuous and reliable positioning, because of its inherent dependency on external electromagnetic signals. Inertial Navigation System (INS) is the implementation of inertial sensors to determine the position and orientation of a vehicle. As such, inertial navigation has

O. M. Maklouf; Y. El halwagy; M. Beumi; S. D. Hassan

2009-01-01

301

Simulations to recover Earth rotation parameters with GPS system  

NASA Astrophysics Data System (ADS)

Results of simulations conducted to recover within 6 to 24 hours of observations the Earth Rotation Parameters (ERP) with the Global Positionning System (GPS) are presented. The whole GPS constellation supported by a maximum of 10 ground stations has been used as the basis system for data collection. The observed quantity is the integration of the Doppler frequency on dual frequency mode. Perturbations are applied : on reference orbits for which the errors have a maximum variance of 1 meter both in along track and range components, on the coordinates of the tracking network whose the consistency is modified with a variance of 10 cm and on the tropospheric refraction on which an error of 2 percent is accepted. Precisions of the subdecimeter level, both for Polar Motion and UT1, are very promising and compete with those obtained by other technics like LASER ranging and Very Long Baseline Interferometry (VLBI). As a byproduct this simulation also shows that the interest of GPS for absolute positioning must be very limited and indicates that absolute positioning deduced from GPS data are not better than those obtained with the TRANSIT system.

Pâquet, P.; Louis, L.

302

The changing world of global navigation satellite systems  

NASA Astrophysics Data System (ADS)

The world of global navigation satellite systems (GNSS) has been changing very rapidly during the last years. New constellations are being developed in Europe (Galileo), India (IRNSS), Japan (QZNSS) and China (Compass), while both the US GPS and the Russian GLONASS programmes are engaged in very significant mediumto long-term improvements, which will make them even more valuable in the coming years to an ever wider range of civilian users. In addition, powerful regional augmentation systems are becoming (or have already become) operational, providing users with important real time information concerning the integrity of the signals being broadcast by those two systems: these include the US WAAS, the European EGNOS, the Japanese MSAS, the Indian GAGAN and others. Following a number of United Nations sponsored regional workshops, a report by an ad hoc UN "GNSS Action Team" and several preparatory meetings, the International Committee on GNSS (ICG) was established in December 2005 in Vienna, Austria. The ICG is an informal body with the main objective of promoting cooperation on matters of mutual interest related to civil satellite-based positioning, navigation, timing, and value-added services, as well as compatibility and interoperability among the GNSS systems. A further important objective is to encourage the use of GNSS to support sustainable development, particularly in the developing countries. The United Nations Office for Outer Space Affairs (UNOOSA) plays a key role in facilitating the work of the ICG. The members of the Committee are GNSS system providers, while international organisations representing users of GNSS can qualify for participation in the work of the Committee as associate members or observers. The interests of the space geodetic, mapping and timing communities are represented in particular through ICG associate membership of the IGS, IAG, FIG, IERS, while BIPM is an ICG observer. This paper will highlight the background of these developments and focus on the concerns of the ICG, especially from the point of view of the user organisations.

Dow, John M.; Neilan, Ruth E.; Higgins, Matt; Arias, Felicitas

303

Homing Pigeons Only Navigate in Air with Intact Environmental Odours: A Test of the Olfactory Activation Hypothesis with GPS Data Loggers  

PubMed Central

A large body of evidence has shown that anosmic pigeons are impaired in their navigation. However, the role of odours in navigation is still subject to debate. While according to the olfactory navigation hypothesis homing pigeons possess a navigational map based on the distribution of environmental odours, the olfactory activation hypothesis proposes that odour perception is only needed to activate a navigational mechanism based on cues of another nature. Here we tested experimentally whether the perception of artificial odours is sufficient to allow pigeons to navigate, as expected from the olfactory activation hypothesis. We transported three groups of pigeons in air-tight containers to release sites 53 and 61 km from home in three different olfactory conditions. The Control group received natural environmental air; both the Pure Air and the Artificial Odour groups received pure air filtered through an active charcoal filter. Only the Artificial Odour group received additional puffs of artificial odours until release. We then released pigeons while recording their tracks with 1 Hz GPS data loggers. We also followed non-homing pigeons using an aerial data readout to a Cessna plane, allowing, for the first time, the tracking of non-homing homing pigeons. Within the first hour after release, the pigeons in both the Artificial Odour and the Pure Air group (receiving no environmental odours) showed impaired navigational performances at each release site. Our data provide evidence against an activation role of odours in navigation, and document that pigeons only navigate well when they perceive environmental odours.

Gagliardo, Anna; Ioale, Paolo; Filannino, Caterina; Wikelski, Martin

2011-01-01

304

Inertial navigation system for directional surveying  

SciTech Connect

A Wellbore Inertial Navigation System (WINS) was developed and tested. Developed for directional surveying of geothermal, oil, and gas wells, the system uses gyros and accelerometers to obtain survey errors of less than 10 ft (approx. 3 m) in a 10,000-ft (approx. 300-m) well. The tool, which communicates with a computer at the surface, is 4 in. (approx. 10 cm) in diameter and 20 ft (approx. 6.1 m) long. The concept and hardware is based on a system developed by Sandia for flight vehicles.

Kohler, S.M.

1982-09-01

305

Evaluating GPS performance in the marine environment  

Microsoft Academic Search

In connection with an investigation involving the comparison of a GPS Clear\\/Access (C\\/A) channel receiver\\/processor with other marine navigation systems, a GPS C\\/A receiver\\/processor was installed on the research vessel Gyre. A description is presented of the installed system, the kinds of data recorded, and the postprocessing techniques employed to provide both absolute and relative analyses of the tested navigational

T. Rhyne; P. Noe

1980-01-01

306

TV system for navigation and guidance  

NASA Astrophysics Data System (ADS)

A TV system for navigation and guidance (TVSNG) has been designed for solving the navigation and scientific tasks of the Phobos-Grunt mission. It consists of two narrow-angle and two wide-angle television cameras. Each camera has a built-in processor for the real-time processing of received images. The program of TVSNG observations includes three modes: Imaging of Stars, Sequential Imaging, and Landing. The first two modes will be used to calibrate the TVSNG against the stars, to take images of Phobos and Mars, and to detect the dust rings of Mars. In the Landing mode, the height and velocity components of the spacecraft during the landing on Phobos will be measured, and an autonomous selection of the landing site will be made.

Avanesov, G. A.; Gordeev, R. V.; Grishin, V. A.; Zhukov, B. S.; Zhukov, S. B.; Kolomeets, E. V.; Krasnopevtseva, E. B.; Kudelin, M. I.; Krupin, A. A.; Murav'ev, V. M.; Forsh, A. A.

2010-10-01

307

AN ALTERNATIVE GPS\\/INS INTEGRATION METHOD  

Microsoft Academic Search

The Institute of Navigation of Stuttgart University utilises an in-house-developed airborne laser scanner system (ScaLARS) for the acquisition of topographic data. The geo-referencing of the laser data results from processing differential GPS carrier phase data and integrating the GPS-determined trajectory with incremental velocity and angular rate data from an inertial measurement unit (IMU). So far, the GPS\\/IMU integration utilises a

A. Seifert; A. Kleusberg

308

Global Positioning System (GPS) Time Dissemination for Real-Time Applications  

Microsoft Academic Search

This paper presents an overview of the Global Positioning System (GPS) for the potential precise time and time interval user with special reference to real -time systems. An overview of GPS operation is presented and GPS error sources are described as they relate to the timing user. A review of receiver types and receiver tasks provides the basis for understanding

Peter H. Dana

1997-01-01

309

US Coast Guard differential GPS network  

SciTech Connect

In order to aid navigation and to prevent disasters such as oil spills, collisions, and wrecks of vessels and aircraft, the US Coast Guard is charged with establishing, maintaining, and operating electronic aids to navigation. In a technological advance developed and operated by the Department of Defense, the global positioning system (GPS) provides all-weather global coverage, 24 hours/day at unprecedented accuracies. GPS provides standard positioning service (SPS) and precise positioning service (PPS). By applying differential techniques to GPS, navigational accuracies of better than 10 meters can be achieved. For the first time, an all-weather system is possible to meet all the marine navigator's needs including harbor and harbor approach navigation. This should revolutionize navigation safety and efficiency, surveying operations, search and rescue operations, and underwater mine disposal efficiency and safety.

Alsip, D.H.; Butler, J.M.; Radice, J.T.

1993-03-01

310

GPS\\/INS navigation precision and its effect on airborne radio occultation retrieval accuracy  

Microsoft Academic Search

An airborne radio occultation (RO) system has been developed to retrieve atmospheric profiles of refractivity, moisture, and\\u000a temperature. The long-term objective of such a system is deployment on commercial aircraft to increase the quantity of moisture\\u000a observations in flight corridors in order to improve weather forecast accuracy. However, there are several factors important\\u000a to operational feasibility that have an impact

Paytsar Muradyan; Jennifer S. Haase; Feiqin Xie; James L. Garrison; Justin Voo

2011-01-01

311

Autonomous navigation algorithm for spacecrafts based on dual quaternion  

Microsoft Academic Search

Celestial Navigation System (CNS), Inertial Navigation System (INS), Global Navigation Satellite System (GNSS), such as GPS, GLONASS, GALILEO and Compass etc, and the integrations of them are some methods of autonomous navigation for space. But these methods must be depended on the high speed links of the communications network. Moreover, the precision of CNS is always worse, and can not

Kezhao Li; Jianping Yuan; Xiaokui Yue; Qun Fang

2007-01-01

312

Precision relative navigation solution for autonomous operations in close proximity  

Microsoft Academic Search

The ability to provide highly accurate and reliable relative navigation information in real time is a key enabling technology for autonomous operations between moving platforms in close proximity. Northrop Grummanpsilas Navigation Systems Sivision (NSD) has developed an innovative approach to relative navigation that fuses Global Positioning System (GPS) pseudorange and carrier phase measurements with Inertial Navigation System (INS) data and

K. Liu; C. Moore; R. Buchler; P. Bruner; A. Fax; J. L. Hinchman; B. T. Nguyen; D. E. Nelson; F. Ventrone; B. R. Thorward

2008-01-01

313

Hybrid simulation system study of SINS\\/CNS integrated navigation  

Microsoft Academic Search

In flight tests, to demonstrate the performance of integrated navigation systems, which are strapdown inertial navigation systems\\/celestial navigation systems (SINS\\/CNS), will involve a lot of effort and a heavy financial budget. So, it is important to design a functional self-contained hardware in a loop simulation system on the ground for solving the verification of SINS\\/CNS integrated navigation systems. Aiming at

Quan Wei; Fang Jiancheng; Xu Fan; Sheng Wei

2008-01-01

314

Automatic navigation system for electric power vehicles with EPS  

Microsoft Academic Search

In this research, automatic navigation control system is developed for agricultural electric power vehicles. Electric power steering (EPS) systems have many advantages over traditional hydraulic power steering systems in engine efficiency and space efficiency. So the electric power vehicle for experiment equips EPS system. Navigation control method, fuzzy control steering and path planning are discussed in detail. Navigation control method

Zhou Jianjun; Zhang Man; Cao Min'gang; Li Su; Liu Bin

2008-01-01

315

GPS-based outdoor activity pattern recording and analysis system.  

PubMed

In this paper, a recording and analysis system is designed and developed for outdoor activity patterns characterization. Some mental problems of aging, especially the occurrence of dementia, are not easily noticed in early stage. In this study, the proposed system is employed for outdoor activity patterns analysis. From the pattern analysis, the abnormal activity which is different from the usual patterns may be differentiated and warned. The proposed system integrates the tablet PC and GPS to track and to detect the occurrence of abnormal condition off-line. In the beginning, the sequence of GPS data is segmented in time frame, and represented in vector form for data reduction. Some filtering technique is also applied for noise reduction. PMID:24109899

Chen, Yan-Ming; Cheng, Kuo-Sheng

2013-07-01

316

Determination of GPS-Galileo Time Offset to Support System Interoperability  

Microsoft Academic Search

ABSTRACT In this paper we discuss the relevance of and options for determination of the time offset between,GPS and Galileo. We,also present results of real -world tests where,clocks,of selected time,laboratories were playing the role of the Galileo System Time and the GPS Time was derived from GPS measurements.,

Alexandre Moudrak; Carine Bruyninx; Andreas Bauch; Pascale Defraigne; Andriy Konovaltsev; Jens Hammesfahr

317

Applications of Global Positioning System (GPS) in geodynamics: with three examples from Turkey  

Microsoft Academic Search

Global Positioning System (GPS) has been very useful tool for the last two decades in the area of geodynamics because or the validation of the GPS results by the Very Long Baseline Interferometry (VLBI) and Satellite Laser Ranging (SLR) observations. The modest budget requirement and the high accuracy relative positioning availability of GPS increased the use of it in determination

H. Yavasoglu; E. Tari; M. Sahin; H. Karaman; T. Erden; S. Bilgi; S. Erdogan

2005-01-01

318

Research on web-based ship navigation system  

Microsoft Academic Search

According to the convenient condition of wireless Internet service along inland rivers in China, the paper researched a web-based ship navigation system for inland river navigation. The system is developed with three-tier network architecture, and runs on web browsers. Based on an electronic channel chart platform developed by COM and JSP, the system provides comprehensive navigation service for ship users,

Ming-yang Pan; Bin Zhang; Jing-feng Hu

2010-01-01

319

Self-guided micro vehicle: An autonomous vehicle with gps navigation and 802.11b communications  

Microsoft Academic Search

To facilitate the learning of automatic navigation systems by engineering students an easy to obtain platform is useful. The topic of this thesis is the design and implementation of a basic self-guided vehicle that can be programmed and expanded by anyone possessing basic experience with the C programming language. The Self-Guided Micro Vehicle, (SGMV), uses off-the-shelf easy to obtain parts

Roberto J Guerra

2005-01-01

320

Test of GBAS integrity monitoring system using GPS simulator  

Microsoft Academic Search

In recent years, many countries are developing aircraft navigation systems using GNSS(Global Navigation Satellite System),\\u000a because GNSS has many technical and economic benefits. International organizations as ICAO(International Civil Aviation Organization)\\u000a and RTCA(Radio Technical Commission for Aeronautics) set up international standards of GBAS(Ground Based Augmentation System)\\u000a using GNSS and recommend countries to develop GBAS that is based on the standards. To

Yun Young-sun; Park Sung-min; Kee Chang-don

2003-01-01

321

The state?of?the?art in marine navigation  

Microsoft Academic Search

The art and science of navigation date back to antiquity. Beginning with procedures one step removed from black magic, navigation has progressed through the refined skill of the celestial navigator, the explosive development of electronic systems after the Second World War, to the artificial celestial system NAVSTAR GPS. Celestial navigation is certainly the most historic form, metaphysically speaking, and woe

L. Breslau; D. Feldman; A. Manning; D. Olsen

1981-01-01

322

Vibrotactile in-vehicle navigation system  

Microsoft Academic Search

A vibrotactile display, consisting of eight vibrating elements or tactors mounted in a driver’s seat, was tested in a driving simulator. Participants drove with visual, tactile and multimodal navigation displays through a built-up area. Workload and the reaction time to navigation messages were measured for normal and high workload conditions. The results demonstrated that the tactile navigation display reduces the

Jan B. F. Van Erp

2004-01-01

323

Managing wildlife: A spatial information system for GPS collars data  

Microsoft Academic Search

ISAMUD (Integrated System for Analysis and Management of Ungulate Data) is an integrated and modular software platform developed to manage GPS collar data for wildlife management. It is based on an open source spatial database (PostgreSQL and PostGIS) and includes open source data management, geo-statistical analysis and Web services modules (R, QGIS, GRASS, MapServer, Ka-Map) and a proprietary database front-end

Francesca Cagnacci; Ferdinando Urbano

2008-01-01

324

A GPS-Based On-Demand Shuttle Bus System  

Microsoft Academic Search

We propose the implementation of an on-demand system to serve requests to ride shuttles on a university campus. Assuming that each client and each shuttle bus has a GPS device, we devise two online algorithms: the k-means based algorithm, and the general pool-based algorithm. The former has two components: the first deals with the problem of assigning requests to shuttles,

Maria Vanina; Martinez Gerardo; I. Simari; Carlos D. Castillo; Nir J. Peer

325

Practical results of GPS\\/IMU\\/camera system calibration  

Microsoft Academic Search

This article summarizes the results of eleven system calibrations of four GPS\\/IMU\\/optics combinations performed in 2002. In addition to the boresight parameters, the interior orientation parameters appeared to be significant calibration quantities. In the direction perpendicular to the flying direction 20-40 µm systematic errors were present with all the optics. With one of the optics significant focal length correction of

Eija Honkavaara; Risto Ilves; Juha Jaakkola

2002-01-01

326

Connecting Middle Schoolers with Geography using GPS (Global Positioning System)  

Microsoft Academic Search

GPS is an emerging technology that teachers are just starting to tap in to. The educational promise of GPS includes integration with social science, science, mathematics, language arts, cultural competence and more. Teachers can use GPS instruction to foster critical thinking skills and the value of learning. GPS instruction engages multiple intelligences and can be an effective tool to promote

Matt Symonds

2009-01-01

327

Institute of Navigation, Annual Meeting, 42nd, Seattle, WA, June 24-26, 1986, Proceedings  

SciTech Connect

The conference presents papers on the analysis of range and position comparison methods as a means of providing GPS integrity in the user receiver, a software package for predicting the performance of VLF-navigation systems, and measurement errors in GPS observables. Other topics include the architecture and performance of a real time differential GPS ground station, optimal locations of pseudolites for differential GPS, and GPS receiver technologies. Consideration is also given to Australian trials of Phase II Navstar GPS user equipment and the sensitivity of an autonomous navigation landmark tracing system due to the variability of landmark availability and distribution.

Not Available

1986-01-01

328

Position location with the NBS/GPS time transfer system  

NASA Astrophysics Data System (ADS)

The NSB/GPS time transfer system is a low-cost receiver of the GPS C/A code for comparing time standards around the world for time and frequency coordination. In order to achieve the highest accuracy for time and frequency transfer the local user must know the coordinates of the receiver antenna within the GPS coordinate system. For this purpose, a fully automatic position location program is included in the receiver software. The receiver performance for absolute differential positioning was evaluated in experiments over three baselines: short (26 m - 77 m), medium (131 km), and long (240 km). Solutions from the receiver were compared with WGS-72 first order survey points. Absolute positioning error varied from 4.1 m to 10.2 m. A 7.2 m mean absolute positioning error is found over eight separate results in the four experiments. The short and medium baseline differential positioning error varied from 1.2 m to 2.5 m, reflecting a limitation due to multipath delays.

Weiss, M.

329

Navigation in Antarctica Today: The Global Positioning System  

NSDL National Science Digital Library

This site contains information that students use to investigate the use of the Global Positioning System (GPS) in Antarctica and across the globe. They conduct research on the Web to understand how and why GPS is used today. They also complete a hands-on activity that is based on spatial principles similar to those used by GPS; they learn how GPS works by doing on paper the work of GPS satellites in space. Throughout this weeklong activity, students collect their findings in a portfolio. The comprehensive curriculum materials contain teacher tools, which include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, and additional readings. Two activities - a Web research project on GPS and how it is used today, and a hands-on activity - are provided. Interviews with a geophysicist who maps geologic formations beneath the ice and a glaciologist who studies the Antarctic ice sheets movement are included. Other items at this site include a student handout with guidance for putting together portfolios and examples of creative final projects.

330

Estimating Zenith Tropospheric Delays from BeiDou Navigation Satellite System Observations  

PubMed Central

The GNSS derived Zenith Tropospheric Delay (ZTD) plays today a very critical role in meteorological study and weather forecasts, as ZTDs of thousands of GNSS stations are operationally assimilated into numerical weather prediction models. Recently, the Chinese BeiDou Navigation Satellite System (BDS) was officially announced to provide operational services around China and its neighborhood and it was demonstrated to be very promising for precise navigation and positioning. In this contribution, we concentrate on estimating ZTD using BDS observations to assess its capacity for troposphere remote sensing. A local network which is about 250 km from Beijing and comprised of six stations equipped with GPS- and BDS-capable receivers is utilized. Data from 5 to 8 November 2012 collected on the network is processed in network mode using precise orbits and in Precise Point Positioning mode using precise orbits and clocks. The precise orbits and clocks are generated from a tracking network with most of the stations in China and several stations around the world. The derived ZTDs are compared with that estimated from GPS data using the final products of the International GNSS Service (IGS). The comparison shows that the bias and the standard deviation of the ZTD differences are about 2 mm and 5 mm, respectively, which are very close to the differences of GPS ZTD estimated using different software packages.

Xu, Aigong; Xu, Zongqiu; Ge, Maorong; Xu, Xinchao; Zhu, Huizhong; Sui, Xin

2013-01-01

331

Noise analysis for X-ray navigation systems  

Microsoft Academic Search

Much as the Global Positioning System has ushered in an era of autonomous navigation on a global scale, X-ray navigation (XNAV) offers the possibility of autonomous navigation anywhere in the solar system. X-ray astronomers have identified a number of X-ray pulsars whose pulsed emissions have stabilities comparable to atomic clocks. X-ray navigation uses phase measurements from these sources to establish

John Hanson; Suneel Sheikh; Paul Graven; John Collins

2008-01-01

332

Constrained navigation algorithms for strapdown inertial navigation systems with reduced set of sensors  

Microsoft Academic Search

This paper develops a family of algorithms for low-cost strapdown inertial navigation system for land vehicles. Constraints on the motion of land vehicles are defined. They include constraints on vehicle's orientation relative to the Earth surface, and relationship between vehicle's attitude and its velocity direction. Navigation equations are derived that assume validity of these constraints on the vehicle's motion. Compared

Aleksandr Brandt; John F. Gardner

1998-01-01

333

Satellite Navigation Systems for Land Vehicles  

Microsoft Academic Search

Today's motorists often must confirm their route by referring to a roadmap. Looking at a map while driving creates a poor traffic situation, one even more acute for drivers of emergency service vehicles. To address this problem, development engineers at the General Motors Technical Cener and Delco Electronics integrated an experimental GPS receiver into a GM Buick Park Avenue. The

Ronald A. Dork

1987-01-01

334

Plot Your Course - Navigation  

NSDL National Science Digital Library

In this unit, students learn the very basics of navigation, including the different kinds of navigation and their purpose. The concepts of relative and absolute location, latitude, longitude and cardinal directions are discussed, as well as the use and principles of a map and compass. Students discover the history of navigation and learn the importance of math and how it ties into navigational techniques. Understanding how trilateration can determine one's location leads to a lesson on the global positioning system and how to use a GPS receiver. The unit concludes with an overview of orbits and spacecraft trajectories from Earth to other planets.

Integrated Teaching And Learning Program

335

Current status and future of the US Navy satellite navigation system  

NASA Astrophysics Data System (ADS)

The status and future of the US Navy Transit satellite system for maritime navigation are reviewed in the light of its planned replacement by Navstar GPS. The Oscar, Nova, and SOOS satellites; their orbits and performance parameters; the Scout launcher; the tracking network; and the correction procedures for ionospheric refraction are characterized and illustrated with drawings, diagrams, and graphs. Current planning calls for maintenance of Transit with the 12 Oscar satellites in ground storage plus two or more of the drag-compensated Nova satellites throughout the transition to Navstar GPS, scheduled for completion in 1992; On-orbit storage of several Oscars (since Scouts will no longer be available after 1987) and/or extending Transit through 1994 are under consideration.

Hoskins, G. W.; Danchik, R. J.

1984-10-01

336

Two systems of spatial representation underlying navigation  

Microsoft Academic Search

We review evidence for two distinct cognitive processes by which humans and animals represent the navigable environment. One\\u000a process uses the shape of the extended 3D surface layout to specify the navigator’s position and orientation. A second process\\u000a uses objects and patterns as beacons to specify the locations of significant objects. Although much of the evidence for these\\u000a processes comes

Sang Ah Lee; Elizabeth S. Spelke

2010-01-01

337

Dual Airborne Laser Scanners Aided Inertial for Improved Autonomous Navigation  

Microsoft Academic Search

A dead-reckoning terrain referenced navigation (TRN) system is presented that uses two airborne laser scanners (ALS) to aid an inertial navigation system (INS). The system uses aircraft autonomous sensors and is capable of performing the dual functions of mapping and navigation simultaneously. The proposed system can potentially serve as a backup to the Global Positioning System (GPS), increase the robustness

ANANTH K. VADLAMANI; MAARTEN UIJT DE HAAG

2009-01-01

338

Simulated Performance of Multiple-signal and Multiple-system Positioning for Land Vehicle Navigation  

Microsoft Academic Search

The modernized GPS and planned GALILEO will provide civil users with multiple signals (or frequencies). In this paper, the navigation performance based on code and phase measurements is investigated for land vehicle users in the continental United States and Southern Canada. For code-based positioning, the availability, accuracy and reliability are estimated with different signal scenarios for GPS, GALILEO and their

Wei Cao; Kyle O'Keefe; Mark Petovello; M. Elizabeth Cannon

2008-01-01

339

75 FR 68701 - Establishment and Amendment of Area Navigation (RNAV) Routes; Alaska  

Federal Register 2010, 2011, 2012, 2013

...Positioning System (GPS)/Global Navigation Satellite System (GNSS) equipment, or Distance Measuring Equipment (DME)/DME Inertial Reference Unit (IRU) navigation capability. The FAA is taking this action to enhance safety and improve the efficient...

2010-11-09

340

75 FR 32120 - Proposed Establishment and Amendment of Area Navigation (RNAV) Routes; Alaska  

Federal Register 2010, 2011, 2012, 2013

...Positioning System (GPS)/ Global Navigation Satellite System (GNSS) equipment, or Distance Measuring Equipment (DME)/DME Inertial Reference Unit (IRU) navigation capability. The FAA is proposing this action to enhance safety and improve the...

2010-06-07

341

Innovative astronaut navigation system based on smart integrated sensors  

Microsoft Academic Search

Original algorithms for navigation on the surface of Mars planet, especially applied to astronauts, are proposed in this paper. The autonomous navigation system for astronaut is based on inertial measurement unit (redundant) and Laser (redundant), which permits to localize and navigate in known environment and unknown environment constructing its map in real time, using adaptive algorithms and physical and natural

Hamza Benzerrouk; Alexander Nebylov; Gennady Yatsevitch

2012-01-01

342

Improving program navigation with an active help system  

Microsoft Academic Search

When performing software change tasks, software developers spend a substantial amount of their time navigating dependencies in the code. Despite the availability of numerous tools to aid such navigation, there is evidence to suggest that developers are not using these tools. In this paper, we introduce an active help system, called Spyglass, that suggests tools to aid program navigation as

Petcharat Viriyakattiyaporn; Gail C. Murphy

2010-01-01

343

Implementation of the GPS to Galileo time offset (GGTO)  

Microsoft Academic Search

Precise timing is an inherent part of Global Navigation Satellite Systems (GNSS) like GPS, Glonass and in the future Galileo. In the framework of the interoperability and compatibility discussions between the United States and European Union it was agreed that both GPS and Galileo systems will compute and broadcast the mutual time offset between both system's time scales. This information

J. H. Hahn; E. D. Powers

2005-01-01

344

Applications of an Adaptive Hierarchical Mobile Robot Navigation System  

Microsoft Academic Search

A hierarchical robot navigation system has been developed and implemented on a range of real and simulated mobile robots for two independent research applications. One application is a study on emotion-modulated navigation. The other is an investigation of heterogeneous multi-robot navigation. The navigation framework shared by the various implementations is described. A multi-layered architecture is employed that incorporates reactive control,

Christopher P. Lee-Johnson; Praneel Chand; Dale A. Carnegie

345

GPS synchronized UV communication system performance based on USRP  

NASA Astrophysics Data System (ADS)

Recently, Ultraviolet communication is paid more and more attention, with its solar blind and Non-Line-of-Sight characteristic. However, it is hard to capture and recover the transmitted signal outdoor without synchronized signal. In this work, we integrate Universal Software Radio Peripheral (USRP) into UV communication system and employ GPS as synchronized signal. At receive side, photon counting and adaptive threshold method are used to recover original signal. Through experiments, we test path loss and BER of the system under di erent con guration geometries. Some results are compared to the previous proposed path loss and BER models.

Liao, Linchao; Chen, Gang; Sadler, Brian M.; Li, Zening

2013-09-01

346

Pulsar Navigation in the Solar System  

Microsoft Academic Search

The X-ray Navigation and Autonomous position Verification (XNAV) is tested which use the Crab pulsar under the Space Test Program that use starlight refraction. It provide the way that the spacecraft could autonomously determine its position with respect to an inertial origin. Now we analysis the sensitivity of the exist instrument and the signal process that use radio pulsar navigation

Jiang Dong

2008-01-01

347

Satellite-supported orientation and navigation  

NASA Astrophysics Data System (ADS)

Issues concerning the time, time distribution, and clock synchronization related to GPS and satellite trajectory determination are addressed. Experiments involving preoperational NAVSTAR-GPS and the NAVEX Space Shuttle experiment are described. Projects concerning future navigation and orientation systems using satellites are discussed.

348

Interoperable GPS, GLONASS and GALILEO software receiver  

Microsoft Academic Search

The new and modernized GNSS navigation systems will provide various navigation services and signals for civil user. The system\\u000a operators work on basic interoperability agreements which simplify multi-system navigation receiver architecture and reduce\\u000a its cost. The most current GNSS signals of GPS, GLO- NASS and GALILEO can be processed by one or several classical E-L correlators\\u000a with a look up

P. Ková?; P. Ka?ma?ík; F. Vejražka

2011-01-01

349

Fiber optic gyroscopes and the accomplishments of the DARPA-sponsored GPS guidance package program  

Microsoft Academic Search

The Global Positioning System (GPS) Guidance Package (GGP) Program developed an affordable, navigation-grade, miniature guidance package based on a tightly coupled, integrated combination of a Miniature GPS Receiver (MGR) and miniature Inertial Navigation System (INS) including associated processors and Adaptable Interface Unit (AIU) functions. The GGP INS used Interferometric Fiber Optic Gyroscopes (IFOGs) and micro-machined silicon accelerometers. Several key challenges

Vicki C. LeFevre; William R. Lindberg

2006-01-01

350

The QuakeSim System for GPS Time Series Analysis  

NASA Astrophysics Data System (ADS)

We present a system for analysis of GPS time series data available to geosciences users through a web services / web portal interface. The system provides two time series analysis methods, one based on hidden Markov model (HMM) segmentation, the other based on covariance descriptor analysis (CDA). In addition, it provides data pre-processing routines that perform spike noise removal, linear de-trending, sum-of-sines removal, and common mode removal using probabilistic principle components analysis (PPCA). These components can be composed by the user into the desired series of processing steps for analysis through an intuitive graphical interface. The system is accessed through a web portal that allows both micro-scale (individual station) and macro-scale (whole network) exploration of data sets and analysis results via Google Maps. Users can focus in on or scroll through particular spatial or temporal time windows, or observe dynamic behavior by created movies that display the system state. Analysis results can be exported to KML format for easy combination with other sources of data, such as fault databases and InSAR interferograms. GPS solutions for California member stations of the plate boundary observatory from both the SOPAC and JPL gipsy context groups are automatically imported into the system as that data becomes available. We show the results of the methods as applied to these data sets for an assortment of case studies, and show how the system can be used to analyze both seismic and aseismic signals.

Granat, R. A.; Gao, X.; Pierce, M.; Wang, J.

2010-12-01

351

The satellite configuration of satellite-TV navigation system  

NASA Astrophysics Data System (ADS)

The positioning accuracy and availability of navigation system are affected directly by the quality of satellite configuration. The possible satellite configurations for satellite-TV navigation system are discussed and estimated in this paper. The results show that a well setted configuration or a resonable integration of satellite-TV navigation system and Chinese Loran-C will improve the positioning accuracy and availability of the system.

Gao, Yu-Ping

2001-02-01

352

A navigation and control system for an autonomous rescue vehicle in the space station environment  

NASA Astrophysics Data System (ADS)

A navigation and control system was designed and implemented for an orbital autonomous rescue vehicle envisioned to retrieve astronauts or equipment in the case that they become disengaged from the space station. The rescue vehicle, termed the Extra-Vehicular Activity Retriever (EVAR), has an on-board inertial measurement unit ahd GPS receivers for self state estimation, a laser range imager (LRI) and cameras for object state estimation, and a data link for reception of space station state information. The states of the retriever and objects (obstacles and the target object) are estimated by inertial state propagation which is corrected via measurements from the GPS, the LRI system, or the camera system. Kalman filters are utilized to perform sensor fusion and estimate the state propagation errors. Control actuation is performed by a Manned Maneuvering Unit (MMU). Phase plane control techniques are used to control the rotational and translational state of the retriever. The translational controller provides station-keeping or motion along either Clohessy-Wiltshire trajectories or straight line trajectories in the LVLH frame of any sufficiently observed object or of the space station. The software was used to successfully control a prototype EVAR on an air bearing floor facility, and a simulated EVAR operating in a simulated orbital environment. The design of the navigation system and the control system are presented. Also discussed are the hardware systems and the overall software architecture.

Merkel, Lawrence

353

What is GPS?  

NSDL National Science Digital Library

This site from Garmin describes GPS systems and the way that they work. Topics include the accuracy of GPS, the 24 satellites that make up the GPS space segment, the two low power radio signals that GPS satellites transmit, and the sources of GPS signal errors.

Ltd., Garmin

354

Improvement of the GPS/A system for extensive observation along subduction zones around Japan  

NASA Astrophysics Data System (ADS)

The M9.0 earthquake in March 2011 along the Japan Trench off Tohoku has elucidated that it is crucial to geodetically observe seismic coupling on the subduction plate boundary, and that the most important observation that should be strengthened is seafloor geodetic observation, especially on the deep seafloor near the trench axis. Repeated observation of GPS/Acoustic (GPS/A) seafloor positioning is the most probable way to cope with the requirement. The observation is urgent along the Japan Trench to analyze how the stress was accumulated that caused the giant earthquake. It is also important along the Nankai Trough off southwestern Japan where another giant earthquake can be being prepared. These surveys will aim at mapping of seismic coupling, and GPS/A observation points should be extended to be arrays in focused areas. On the other hand, ship time for the surveys will remain limited. Extensive geodetic observation along the subduction zones around Japan will not be attained without improvement in GPS/A observation systems. The first step that we are planning is common use of seafloor instruments. In Japan, mainly three groups are engaged in seafloor geodetic measurement by means of GPS/Acoustic technique with their own type of instruments. This has prevented us to conduct mutual surveys to each other, which would become crucial when number of survey sites increases in the future. A precision acoustic transponder (PXP) is a mirror transponder, which returns a received signal without any change after a fixed delay. Considering that different PXPs have intrinsically similar operational principle, we plan to develop PXPs which can be used in common. Then there will be more chance of repeated observations and evaluation of the observed results. A joint observation will An AUV (autonomous underwater vehicle) or an auto-navigation buoy can be an alternative of a survey ship. Asada and Ura (2005) have investigated a GPS/A observation system by using an AUV. Extending surveys into the deeper ocean to cover the wide range of possible rupture area is another important item to be carried out. Our current sites lie on the seafloor shallower than 3500 m. However, the 2011 Tohoku-oki earthquake revealed that the rupture area extended close to the trench, where depth ranges 5000 to 7000 m. Observation of tectonic motion of the incoming plate which is under deep sea is another target of seafloor geodesy. GPS/A observation on such a deep seafloor was technically confirmed (Osada et al., 2003, EPS), but there has been no report on repeated seafloor positioning. We plan to extend the depth range of GPS/A observation by optimizing threshold of responding level of the PXPs as well as increasing its power. Assessment of the application needs careful offshore test.

Fujimoto, H.; Kido, M.; Tadokoro, K.; Sato, M.; Ishikawa, T.; Asada, A.; Mochizuki, M.

2011-12-01

355

An interdisciplinary approach at studying the Earth-Sun system with GPS\\/GNSS and GPS-like signals  

Microsoft Academic Search

The value of the Global Positioning System (GPS) measurements to atmospheric science, space physics, and ocean science, is now emerging or showing a potential to play a major role in the evolving programs of NASA, NSF and NOAA. The objective of this communication is to identify and articulate the key scientific questions that are optimally, or perhaps uniquely, addressed by

C. Zuffada; G. Hajj; T. Mannucci; Y. Chao; C. Ao; J. Zumberge

2005-01-01

356

Augmentation of a navigation reference system with differential global positioning system pseudorange measurements  

Microsoft Academic Search

To quantify the performance of navigation systems, the US Air Force has used a baseline navigation system, the Completely Integrated Reference Instrumentation System (CIRIS), which obtains an accurate navigation solution by combining information from three major subsystems. Although the navigation solution produced by CIRIS is accurate, it will soon be inadequate as the standard against which future navigation systems can

W. J. Negast; R. N. Paschall

1992-01-01

357

Enhancing positioning accuracy in urban terrain by fusing data from a GPS receiver, inertial sensors, stereo-camera and digital maps for pedestrian navigation.  

PubMed

The paper presents an algorithm for estimating a pedestrian location in an urban environment. The algorithm is based on the particle filter and uses different data sources: a GPS receiver, inertial sensors, probability maps and a stereo camera. Inertial sensors are used to estimate a relative displacement of a pedestrian. A gyroscope estimates a change in the heading direction. An accelerometer is used to count a pedestrian's steps and their lengths. The so-called probability maps help to limit GPS inaccuracy by imposing constraints on pedestrian kinematics, e.g., it is assumed that a pedestrian cannot cross buildings, fences etc. This limits position inaccuracy to ca. 10 m. Incorporation of depth estimates derived from a stereo camera that are compared to the 3D model of an environment has enabled further reduction of positioning errors. As a result, for 90% of the time, the algorithm is able to estimate a pedestrian location with an error smaller than 2 m, compared to an error of 6.5 m for a navigation based solely on GPS. PMID:22969321

Przemyslaw, Baranski; Pawel, Strumillo

2012-05-25

358

GPS PWV Information System of the Decision Making Support System Prototype for Typhoon-Flood Disaster  

NASA Astrophysics Data System (ADS)

Under the frame of the Global Earth Observation System of Systems (GEOSS), we are developing a GPS Precipitable Water Vapor (PWV) Information System (IS) of the Decision Making Support System (DMSS) Prototype for Typhoon-Flood Disaster, funded by the Korea Research Council of Fundamental Science and Technology. The system is highly demanded because most, about 90%, of natural disasters happening in Korea have been caused by water, i.e. typhoon, flood, heavy rain and snow, etc. The DMSS prototype, developed mainly by the Korea Information Science and Technology Institute, consists of three sub-systems: observation, prediction, and assessment systems, which are based on the technology of data grid, computation grid, and access grid, respectively. With the augmented reality technology applied, the DMSS web portal that integrates the sub-systems will help the decision makers to access to the DMSS effectively. The GPS PWV IS is being developed as a component of the DMSS prototype for Typhoon-Flood Disaster. PWV estimated from GPS signal delay could be useful to enhance the reliability in numerical weather prediction, nowcasting, climate change monitoring, and so on. As a leading group on GPS Meteorology, the Korea Astronomy and Space Science Institute (KASI) is taking a charge of the GPS PWV IS development. The system will provide the near-real time PWV information based on the nine permanent GPS stations of KASI. Each GPS station of KASI equipped digital weather sensor and provided their own data to the center of KASI in real time. They are expected to be used for operational weather forecasting, researches, instrument validation, etc. Here we introduce the current and future status of our GPS PWV IS, presenting its detailed structures such as Meta Data and Data Base structure, data processing strategy and procedure, flow of information, and application of augmented reality technology.

Sohn, D. H.; Shin, Y. H.; Cho, J. H.; Park, J. U.

2009-04-01

359

Peformance limits for multiplatform scene-referenced navigation systems  

NASA Astrophysics Data System (ADS)

The accuracy of aircraft/weapon navigation systems has improved dramatically since the introduction of global positioning systems and terrain-referenced navigation systems into integrated navigation suites. Future improvements, in terms of reliability and accuracy, could arise from the inclusion of navigation systems based on the correlation of known ground features with imagery from a visual band or infrared sensor, often called scene matching and area correlation or scene-referenced navigation. This paper considers the use of multi-platform fusion techniques to improve on the performance of individual scene-referenced navigation systems. Consideration is also given to the potential benefits of multi-platform fusion for scene-referenced object localization algorithms that could be used in association with infrared targeting aids.

Ralph, Jason F.; Januarius, Eleanor M.; Smith, Moira I.; Edwards, Kenneth L.; Bernhardt, Mark

2001-03-01

360

Lane detection system for autonomous vehicle navigation  

NASA Astrophysics Data System (ADS)

This paper represents the vision processing solution used for lane detection by the Insight Racing team, for DARPA Grand Challenge 2007. The problem involves detecting the lane markings for maintaining the position of the autonomous vehicle within the lane, at usable frame rate. This paper describes a method based on color interpretation and scanning based edge detection for quick and reliable results. First the color information is extracted from the image using RGB to HSV transform and mapped to the Munsell color system. Next, the regions of useful color are scanned adaptively to do an equivalent of single pixel edge detection in one stage. These edges are then processed using Hough Transform to yield lines, which are then segmented, grouped and approximated to reduce the number of lines representing straight and curved lane markings. The final lines are then numbered and sent to the master controller for each frame. This allows the master controller to pick the bounding lane markings and center the vehicle accordingly and navigate autonomously. OpenGL is used to display the results. The solution has been tested and is being used by Insight Racing team for their entry to the DARPA Grand Challenge 2007.

Bhatia, Amit

2007-09-01

361

Applications of GPS-RTK technique in a new digital photogrammetric camera system  

Microsoft Academic Search

The feasibility for collecting the coordinates of GCPs (ground control points) makes real-time kinematic GPS (GPS-RTK) the best optimal choice in the photogrammetric field work. In this paper a new digital photogrammetric camera system is introduced, firstly. And then how the GPS-RTK technique is used in the new camera system is illustrated. Some preliminary results are made following the data

Liang Hongyou; Gu Xingfa; Yu Tao; Wang Liuzhao; Qiao Chaofei

2007-01-01

362

A GPS\\/GIS Integrated System for Urban Traffic Flow Analysis  

Microsoft Academic Search

In this paper, a GPS\\/GIS integrated system for urban traffic flow analysis is proposed. Urban GIS-T data are used to construct the GIS map of urban area when the system begins its work. Afterwards, real-time GPS data of probe vehicles are periodically collected to implement the location amendment. And then, location-amended GPS data are dynamically fitted with the adaptive traffic

Wenhuan Shi; Qing-Jie Kong; Yuncai Liu

2008-01-01

363

Position of GPS in wildlife and habitat mapping  

Microsoft Academic Search

Global positioning system (GPS) technology is being implemented by the Department of Defense and is becoming generally available. Portable, lightweight, low-cost receivers give a rapid readout of location to within 100 feet in a few seconds. The geometry of the satellite GPS system and of the ground-based Long Range Navigation (LORAN) is described. Examples are given of the use of

Dan A. Foster

1993-01-01

364

Improvements in accurate GPS positioning using time series analysis  

Microsoft Academic Search

Although the Global Positioning System (GPS) is used widely in car navigation systems, cell phones, surveying, and other areas, several issues still exist. We focus on the continuous data received in public use of GPS, and propose a new positioning algorithm that uses time series analysis. By fitting an autoregressive model to the time series model of the pseudorange, we

Yuichiro Koyama; Toshiyuki Tanaka

2010-01-01

365

Paving the road to savings with GPS [Automotive Electronics  

Microsoft Academic Search

The global positioning system (GPS) today is the only totally functioning global navigation satellite system. Nearly 50% of businesses that use GPS technologies cite a reduction in transportation travel distance by an average of 231 miles per week, saving nearly US$52,000 in annual fuel savings. This is according to a Motorola, Inc. survey of those in the transportation, manufacturing, and

Bill Fleming

2008-01-01

366

Relationships between GPS-signal propagation errors and EISCAT observations  

Microsoft Academic Search

When travelling through the ionosphere the signals of space-based radio navigation systems such as the Global Positioning System (GPS) are subject to modifications in amplitude, phase and polarization. In particular, phase changes due to refraction lead to propagation errors of up to 50 m for single-frequency GPS users. If both the LI and the L2 frequencies transmitted by the GPS

N. Jakovvski; E. Sardon; E. Engler; A. Jungstand; D. Klähn

1997-01-01

367

A visual navigation system for autonomous land vehicles  

Microsoft Academic Search

A modular system architecture has been developed to support visual navigation by an autonomous land vehicle. The system consists of vision modules performing image processing, three-dimensional shape recovery, and geometric reasoning, as well as modules for planning, navigating, and piloting. The system runs in two distinct modes, bootstrap and feedforward. The bootstrap mode requires analysis of entire images to find

ALLEN M. WAXMAN; JACQUELINE J. LEMOIGNE; LARRY S. DAVIS; BABU SRINIVASAN; TODD R. KUSHNER; Eli Liang; THARAKESH SIDDALINGAIAH

1987-01-01

368

Mission-Based Navigational Behaviour Modeling for Web Recommender Systems  

Microsoft Academic Search

Web recommender systems anticipate the information needs of on-line users and provide them with recommendations to facilitate and personalize their navigation. There are many approaches to building such systems. Among them, using web access logs to generate users' navigational models capable of building a web recommender system is a popular approach, given its non-intrusiveness. However, using only one information channel,

Osmar R. Zaïane; Jia Li; Robert Hayward

2004-01-01

369

A vision based navigation system for autonomous aircraft  

Microsoft Academic Search

A machine perception system for aircraft and helicopters using multiple sensor data for state estimation is presented. By combining conventional aircraft sensors like gyros, accelerometers, artificial horizon, aerodynamic measuring devices and GPS with vision data taken by conventional CCD-cameras mounted on a pan and tilt platform, the position of the craft can be determined as well as the relative position

Simon Fürst; Ernst-Dieter Dickmanns

1999-01-01

370

Implementation of the GPS to Galileo Time Offset (GGTO).  

National Technical Information Service (NTIS)

Precise timing is an inherent part of Global Navigation Satellite Systems 'GNSS' like GPS, Glonass and in the future Galileo. In the framework of the interoperability and compatibility discussions between the United States and European Union it was agreed...

E. D. Powers J. H. Hahn

2005-01-01

371

Performance Analysis of an Ultra-Tightly Integrated GPS and Reduced IMU System  

Microsoft Academic Search

Ultra-tight GPS and inertial measurement unit (IMU) integration has been shown to provide improved tracking performance under weak signal conditions, during high vehicle dynamics and in the presence of jamming. However, for financially sensitive applications such as automobile navigation, the use of a full six degree of freedom IMU is impractical, even when using low cost MEMS-based devices. This paper

M. G. Petovello; D. Sun; G. Lachapelle; M. E. Cannon

2007-01-01

372

An Integrated Inertial Reference-Inertial Navigation System.  

National Technical Information Service (NTIS)

The patent application described and disclosed herein consists of, but is not limited to, a unique integrated inertial reference-inertial navigational system including a local-level inertial platform system, an inertially referenced gyro system, an accura...

F. W. McDonald

1975-01-01

373

Satellite clocks characterization and monitoring for global navigation satellite systems  

Microsoft Academic Search

In Global Navigation Satellite Systems (GNSS) the user’s position is determined measuring the time of flight of the signals broadcast from satellites, which is proportional to the distance between the user and each satellite of the constellation. Time and frequency metrology has an essential role in satellite navigation systems: since a distance can be measured from a time, any error

A. Cernigliaro; I. Sesia

2011-01-01

374

Development of the NASA Valt Digital Navigation System.  

National Technical Information Service (NTIS)

The research to develop and fabricate a terminal area navigation system for use in the NASA VTOL Approach and Landing Technology (VALT) program. The results of that effort are reported. The navigation system developed and fabricated was based on a general...

W. J. Mcconnell E. R. Skutecki A. J. Calzado

1975-01-01

375

An Intelligent Information System for Maritime Navigation Information  

Microsoft Academic Search

This paper describes aspects of an information system being constructed for intelligent information retrieval in maritime navigation applications. The system is based largely on dig- ital nautical charts, and the construction of a taxonomy of chart features and concepts related to the maritime navigation domain is described. This taxonomy is used in formulating queries and sub-queries for disparate sources of

Raphael Malyankar

376

New Projects Planed/launched By Cei Wg On Satellite Navigation Systems  

NASA Astrophysics Data System (ADS)

In the paper a short description of main projects on satellite positioning and naviga- tion in CEI countries is given. Special attention is devoted to the activity of members of Working Group on Satellite Navigation Systems. The projects in which they are involved and results of performed experiments can be specified as follows: - EGNOS positioning - the first results in CEI area, - application of various transmission tech- niques to diffusion of DGPS/RTK data from reference stations (SWIFT/DARC, RDS, radiobeacons, UHF transmission), - development of integrated GPS/INS methods for car navigation and GIS purposes, - development of software for integration of satellite vehicle position with numerical maps for car navigation, monitoring and acquisition of terrestrial data for GIS, - elaboration of method and software development for nav- igation and monitoring of aircraft during approaching and landing phase of flight, - elaboration of methods and software for integration of 3D satellite positions of user with Digital Terrain Model (DTM), - development of digital technology for bathy- metric survey with satellite positioning technique; mapping of shallow waters, lakes, rivers and inland water reservoirs, The recently planned studies and experiments cover land, marine and aircraft satellite navigation with EGNOS system in CEI countries. The project of extension of the EGNOS system to the Central and East European region is under preparation. Other important research is conducted on mapping of roads and rails tracks using integrated DGPS/INS techniques.

Oszczak, S.; Manzoni, G.

377

An Ultrasonic Navigation System for Blind People  

Microsoft Academic Search

The aim of this paper is to investigate the development of a navigation aid for blind and visually impaired people. It is based on a microcontroller with synthetic speech output. This aid is portable and gives information to the user about urban walking routes to point out what decisions to make. On the other hand, and in order to reduce

Mounir Bousbia-Salah; Abdelghani Redjati; M. Fezari; M. Bettayeb

2007-01-01

378

Office of Space Flight Standard Spaceborne Global Positioning System User Equipment Project.  

National Technical Information Service (NTIS)

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 measu...

P. E. Saunders

1991-01-01

379

Evaluation of the 1984 Alaska global positioning system campaign with the Bernese GPS software  

Microsoft Academic Search

During the summer of 1984 five TI-4100 global positioning system (GPS) receivers were used to measure an eight-station network in Alaska and Canada, previously measured with mobile very long baseline interferometry (VLBI) systems, with baselines ranging from 300 km to almost 2700 km. The observations have been processed in the network mode with the Bernese GPS software using orbit improvement

G. Beutler; I. Bauersima; W. Gurtner; M. Rothacher; T. Schildknecht; G. L. Mader; M. D. Abell

1987-01-01

380

Initial results of land-reflected GPS bistatic radar measurements in SMEX02  

Microsoft Academic Search

To investigate scattering of Global Positioning System (GPS) signals from terrain and the potential for remotely sensing soil moisture with the L-band GPS bistatic radar concept, a prototype GPS bistatic radar participated in airborne measurements during the Soil Moisture Experiment 2002 (SMEX02). A 12-channel GPS navigation receiver, modified to perform bistatic radar measurements, was mounted on the NCAR C-130 aircraft

Dallas Masters; Penina Axelrad; Stephen Katzberg

2004-01-01

381

Matching GPS Observations to Locations on a Digital Map  

Microsoft Academic Search

GPS based navigation and route guidance systems are becoming increasingly popular among bus operators, fleet managers and travelers. To provide this functionality, one has to have a GPS receiver, a digital map of the traveled network and software that can associate (match) the user's position with a location on the digital map. Matching the user's location has to be done

Joshua S. Greenfeld

2002-01-01

382

GPS vs Galileo: Balancing for Position in Space  

Microsoft Academic Search

This study comprises an investigation of Europe's motives to develop the independent satellite navigation system known as Galileo, despite the existence of America's successful – and freely available – Global Positioning System (GPS). The study begins with an analysis of both systems to familiarize the reader with global navigation satellite systems (GNSS), to provide an understanding of the strengths and

Scott W. Beidleman

2005-01-01

383

EGNOS European Geostationary Navigation Overlay Service Receiver Terminal  

Microsoft Academic Search

EGNOS the European complement to the GPS and GLONASS systems is operating navigation payloads flown on geostationary satellites. Its role is to augment the performance of the GPS and GLONASS systems by improving their service integrity and the accuracy of their measurements. These two systems were originally designed for military purposes and their services were subsequently offered to civilian users,

S. Haugg; J. Costa; P. Chaves; F. Moreira; N. Niklasch

2001-01-01

384

Comparative advantage between traditional and smart navigation systems  

NASA Astrophysics Data System (ADS)

The smart navigation system that refers to real-time traffic data is believed to be superior to traditional navigation systems. To verify this belief, we created an agent-based traffic model and examined the effect of changing market share of the traditional shortest-travel-time algorithm based navigation and the smart navigation system. We tested our model on the grid and actual metropolitan road network structures. The result reveals that the traditional navigation system have better performance than the smart one as the market share of the smart navigation system exceeds a critical value, which is contrary to conventional expectation. We suggest that the superiority inversion between agent groups is strongly related to the traffic weight function form, and is general. We also found that the relationship of market share, traffic flow density and travel time is determined by the combination of congestion avoidance behavior of the smartly navigated agents and the inefficiency of shortest-travel-time based navigated agents. Our results can be interpreted with the minority game and extended to the diverse topics of opinion dynamics.

Shin, Jeongkyu; Kim, Pan-Jun; Kim, Seunghwan

2013-03-01

385

Functional Performance Specification for an Inertial Navigation System.  

National Technical Information Service (NTIS)

This document defines the functional and performance requirements for the inertial navigation system (INS) simulator that interfaces with the external computer system (ECS) simulator. Both the INS simulator and the ECS simulator are being developed in Ada...

B. C. Meyers N. H. Weiderman

1988-01-01

386

Autonomous Land Vehicle (ALV) Planning and Navigation System.  

National Technical Information Service (NTIS)

The Hughes planning system is designed to achieve the reasoning requirements of the Autonomous Land Vehicle (ALV) for navigation in unconstrained outdoor environments. This system is designed specifically to handle diverse terrain with maximal speed, effi...

D. M. Keirsey J. S. Mitchell D. W. Payton D. Y. Tseng V. S. Wong

1987-01-01

387

Restoration of maritime navigation systems in central American ports  

Microsoft Academic Search

Summary form only given, as follows. This paper describes a project to reinstate maritime navigation in Central American (CA) ports that were devastated by the hurricane that occurred in November 1998. The project objectives were to install navigation facilities rapidly, and to use advanced technologies in the renovation to insure that the capabilities of the new systems would exceed those

A. R. Beam

1999-01-01

388

Strapdown inertial navigation system algorithms based on dual quaternions  

Microsoft Academic Search

The design of strapdown inertial navigation system (INS) algorithms based on dual quaternions is addressed. Dual quaternion is a most concise and efficient mathematical tool to represent rotation and translation simultaneously, i.e., the general displacement of a rigid body. The principle of strapdown inertial navigation is represented using the tool of dual quaternion. It is shown that the principle can

Yuanxin Wu; Xiaoping Hu; Dewen Hu; Tao Li; Junxiang Lian

2005-01-01

389

New techniques for initial alignment of strapdown inertial navigation system  

Microsoft Academic Search

Some new techniques for initial alignment of strapdown inertial navigation system are proposed in this paper. A new solution for the precise azimuth alignment is given in detail. A new prefilter, which consists of an IIR filter and a Kalman filter using hidden Markov model, is designed to attenuate the influence of sensor noise and outer disturbance. Navigation algorithm in

Shaolin Lü; Ling Xie; Jiabin Chen

2009-01-01

390

A WEB-BASED AUTOMATED GPS PROCESSING SYSTEM  

Microsoft Academic Search

ABSTRACT In the conventional scenario for GPS surveying based on the post-processed mode, users have to purchase a minimum of two sets of GPS receiver hardware, as well as the associated processing software package. This is not only a significant capital cost, but

Chalermchon Satirapod; Kenneth Wong; Chris Rizos

2000-01-01

391

GPS instrumentation performance as an ICBM guidance system evaluator  

Microsoft Academic Search

GPS performance on two Minuteman III flight tests is analyzed. It is shown how data of this quality can provide superior evaluation of total guidance error and can be used to identify inflight guidance anomalies. The GPS data on these flights exhibit short-term accuracy equal to the predicted levels. Typically, random errors on the order of 2 ft and .01

R. L. Barkley Jr.; W. H. Hietzke

1982-01-01

392

Integrating Inertial Sensors With Global Positioning System (GPS) for Vehicle Dynamics Control  

Microsoft Academic Search

This paper demonstrates a method of estimating several key vehicle states—sideslip angle, longitudinal velocity, roll and grade—by combining automotive grade inertial sen- sors with a Global Positioning System (GPS) receiver. Kinematic Kalman filters that are independent of uncertain vehicle parameters integrate the inertial sensors with GPS to provide high update estimates of the vehicle states and the sensor biases. Using

Jihan Ryu; J. Christian Gerdes

2004-01-01

393

Global Positioning System (GPS) estimates of crustal deformation in the Marmara Sea region, Northwestern Anatolia  

Microsoft Academic Search

In the Marmara Sea region the relative motion between the Anatolian and Eurasian lithosphere has been measured by means of the modern techniques of space geodesy using the Global Positioning System (GPS). In order to resolve in detail the kinematic field within the active earthquake belts of Northwestern Anatolia, two GPS campaigns were carried out across a dense network consisting

Christian Straub; Hans-Gert Kahle

1994-01-01

394

Analysis of a choke ring groundplane for multipath control in Global Positioning System (GPS) applications  

Microsoft Academic Search

In this paper a computational scheme is presented for accurately predicting the farfield amplitude and phase characteristics of Global Positioning System (GPS) antennas flush-mounted to a corrugated groundplane. The algorithm developed is particularly well-suited in beamshaping of (GPS) antennas in order to provide a high level of multipath rejection. The usefulness of the analytical model has been verified by the

James M. Tranquilla; J. P. Carr; Hussain M. Al-Rizzo

1994-01-01

395

Global Positioning System (GPS) location accuracy improvement due to Selective Availability removal  

Microsoft Academic Search

Global Positioning System (GPS) is an important new technology for spatio-temporal behaviour studies of animals. Differential correction improves location accuracy. Previously, it mostly removed partially the influence of Selective Availability (SA). SA was deactivated in May 2000. The aim of this study was to quantify the influence of SA cancellation on location accuracy of various GPS receivers. We tested the

Christophe Adrados; Irène Girard; Jean-Paul Gendner; Georges Janeau

2002-01-01

396

Systems analysis of GPS electrical power system redesign. Master`s thesis  

SciTech Connect

A systematic analysis is applied to the electrical power subsystem of the Global Positioning Satellite (GPS) system. Results determined the most appropriate power source and conversion system options. The best electrical power subsystem options found in the analysis include a solar power source with either a dynamic or direct conversion technique, and a direct conversion nuclear source. The two solar options are designed, at a low level of detail, to provide the same level of power the current GPS photovoltaic solar array system provides. These two designs are then compared with the current system, stressing mass, and area.

Walker, K.J.

1995-12-01

397

Garmin: What Is GPS?  

NSDL National Science Digital Library

This resource, published by a commercial producer of GPS equipment, introduces students to the concept of Global Positioning Systems (GPS). Topics include how GPS works and how accurate it is. There is also a brief description of the satellite network that makes the system work, and some sources of error in the GPS signal.

398

GPS Time Steering.  

National Technical Information Service (NTIS)

The importance of the Global Positioning System (GPS) for global time transfer makes it desirable to steer GPS time as closely as possible to the UTC rate. Currently, GPS time is maintained to satisfy two system requirements. First, GPS time is steered to...

D. W. Allan H. F. Fliegel W. J. Klepczynski

1986-01-01

399

Autonomous navigation of USAF spacecraft  

NASA Astrophysics Data System (ADS)

The U. S. Air Force is developing satellite-borne sensors to enable autonomous navigation of spacecraft in the near future. This study compares the observations from several medium-accuracy space sensors, such as the existing telescopic space sextant, with those of future matrix-type sensors. The large field of view of matrix sensors will allow them to determine the Earth horizon to approximately an order of magnitude better than current infrared sensors by observing atmospheric refraction of stellar light. This horizon determination will give the matrix sensors an accuracy of less than 1 km. The limiting factor in Earth-horizon determination is the modeling of atmospheric refraction effects. For high-accuracy requirements (100 meters or less), the Global Positioning System (GPS) offers the only near-term solution. A relative navigation technique using range and Doppler data is proposed for autonomous navigation of the GPS satellites. The navigation accuracy of this technique is evaluated by consider covariance analysis and by processing corrupted data through a reduced-order onboard Sequentially Partitioned Algorithm. The algorithm is stable and for the GPS system produces in-plane accuracy of 40 meters over twenty days. However, out-of-plane motion is shown to be unobservable in the GPS-to-GPS tracking mode, and errors of up to 1.5 km over 60 days are experienced. For this reason, a supplemental transmitter on the ground or in a different orbit is recommended.

Ferguson, J. R., Jr.

1983-12-01

400

Intelligent personal navigator supported by knowledge-based systems for estimating dead reckoning navigation parameters  

Microsoft Academic Search

Personal navigators (PN) have been studied for about a decade in different fields and applications, such as safety and rescue operations, security and emergency services, and police and military applications. The common goal of all these applications is to provide precise and reliable position, velocity, and heading information of each individual in various environments. In the PN system developed in

Shahram Moafipoor

2010-01-01

401

Navigation Satellites: Their Future Potential  

Microsoft Academic Search

The United States Department of Defense is developing a new generation of navigation satellites known as the Navstar Global Positioning System or GPS. When the full system of 18 satellites is deployed in the late 1980s, highly accurate information on position, velocity, and time will be available continuously to users anywhere in the world. This capability has already been demonstrated

W. E. Ramsey

1984-01-01

402

The International GNSS Service in a changing landscape of Global Navigation Satellite Systems  

NASA Astrophysics Data System (ADS)

The International GNSS Service (IGS) is an international activity involving more than 200 participating organisations in over 80 countries with a track record of one and a half decades of successful operations. The IGS is a service of the International Association of Geodesy (IAG). It primarily supports scientific research based on highly precise and accurate Earth observations using the technologies of Global Navigation Satellite Systems (GNSS), primarily the US Global Positioning System (GPS). The mission of the IGS is “to provide the highest-quality GNSS data and products in support of the terrestrial reference frame, Earth rotation, Earth observation and research, positioning, navigation and timing and other applications that benefit society”. The IGS will continue to support the IAG’s initiative to coordinate cross-technique global geodesy for the next decade, via the development of the Global Geodetic Observing System (GGOS), which focuses on the needs of global geodesy at the mm-level. IGS activities are fundamental to scientific disciplines related to climate, weather, sea level change, and space weather. The IGS also supports many other applications, including precise navigation, machine automation, and surveying and mapping. This article discusses the IGS Strategic Plan and future directions of the globally-coordinated ~400 station IGS network, tracking data and information products, and outlines the scope of a few of its numerous working groups and pilot projects as the world anticipates a truly multi-system GNSS in the coming decade.

Dow, John M.; Neilan, R. E.; Rizos, C.

2009-03-01

403

Dual-transponder Precision Navigation System for Synthetic Aperture Sonar  

Microsoft Academic Search

The technical details of a dual-transponder, long-baseline positioning system to mea- sure the sway of a free towed Synthetic Aperture Sonar (SAS) are presented. The sway is measured with respect to freely deployed, battery powered, transponders which sit stationary on the seabed connected via cables to floating buoys housing high-accuracy GPS timing receivers. A T\\/R switch allows a single hydrophone

E N Pilbrow; M P Hayes; P T Gough

2002-01-01

404

Inertial navigation for the urban warrior  

Microsoft Academic Search

Individual soldier geolocation in situations such as urban warfare where loss of Global Positioning System (GPS) track can impact mission success has become a critical problem. Concepts such as RF 'time difference of arrival' and 'dead reckoning' techniques have not demonstrated their ability to support navigation reliably inside buildings on their own. Inertial navigation is the only technology that operates

John Elwell

1999-01-01

405

Doppler radar and MEMS gyro augmented DGPS for large vehicle navigation  

Microsoft Academic Search

This paper presents the development of a land vehi- cle navigation system that provides accurate and uninterrupted positioning. A ground speed Doppler radar and one MEMS gyroscope are used to augment differential GPS (DGPS) and provide accurate navigation during GPS outages. The goal is to maintain a position accuracy of 2 meters or better for 15 seconds when an accurate

Jussi Parviainen; Martti Kirkko-Jaakkola; Pavel Davidson; Manuel A. Vazquez Lopez; Jussi Collin

2011-01-01

406

Optimal on-airport monitoring of the integrity of GPS-based landing systems  

NASA Astrophysics Data System (ADS)

The Global Positioning System (GPS) is a satellite-based radio navigation system. The Local Area Augmentation System (LAAS) is a version of Differential GPS (DGPS) designed to reliably support aircraft precision approaches. The Integrity Monitor Testbed (IMT) is a prototype of the LAAS Ground Facility (LGF) that is used to evaluate whether the LGF can meet system integrity requirements. To insure high integrity, the IMT has a variety of monitors to detect all possible failures. It also contains a failure-handling logic, known as Executive Monitoring (EXM), to exclude faulty measurements and recover once the failure disappears. Spatial ionospheric gradients are major threats to the LAAS. One focus of this thesis is exploring methods to quickly detect ionospheric gradients given the required low probability of false alarms. The first part of the thesis introduces GPS, LAAS, and the IMT and explains the algorithms and functionalities of IMT integrity monitors in detail. It then analyzes the failure responses of the integrity monitors under the most general measurement failure model. This analysis not only qualitatively maps the integrity monitors into the entire failure space, but also provides a tool to quantitatively compare the performance of different integrity monitors. In addition, the analysis examines the limitations of the existing monitors in detecting small but hazardous ionospheric gradients. The divergence Cumulative Sum (CUSUM) method is then derived and assessed. It can reduce the time required to detect marginal ionospheric gradients by about 30%. With the divergence CUSUM method implemented in the IMT, system integrity and performance are greatly improved. Different monitors can respond to the same failures. The last part of this thesis shows that the combination of these different monitors can detect certain failures more quickly than any individual monitor. This idea leads to a new method, called failure-specific testing, which can significantly improve the detection speed of small failures, including ionospheric gradients. Used as aids to diagnosis and exclusion, failure-specific tests can soften the current EXM logic so that the LAAS can meet the tighter continuity requirements that apply to Category III precision landings.

Xie, Gang

2004-11-01

407

Personal Navigation System Based on Inertial and Magnetic Field Measurements.  

National Technical Information Service (NTIS)

This work describes the development and testing of a personal navigation system (PNS) for use during normal walking on level ground surfaces. A shoe-worn miniature inertial/magnetic measurement unit (IMMU), which is comprised of accelerometers, magnetomet...

J. Calusdian

2010-01-01

408

Design and Implementation of Autonomous Navigation System for Mobile Harbors  

Microsoft Academic Search

\\u000a This paper describes an implementation of an autonomous navigation system for a USV-type Mobile Harbor (MH) prototype and\\u000a for multiple MHs. The MH is a novel maritime container transport solution that can go out to a ship to load\\/unload containers\\u000a at sea and take them to their destination ports. We demonstrate the feasibility of the navigation system for a MH

Iksu Shin; Yuseok Bang; Donghoon Kim; Jongdae Jung; Hyun Myung

2010-01-01

409

Performance of GPS, GLONASS and Galileo  

Microsoft Academic Search

After a short introduction, an overview about the Global Navigation Satellite Systems (GNSS) GPS, GLONASS and Galileo is given. For each system, a status report is presented and then the three main positioning algorithms: Single Point Positioning, Differential Pseudorange and Carrier Phase Positioning are described. In the Summary, the systems are compared and and outlook is given. This paper describes

BERND EISSFELLER; GERALD AMERES; VICTORIA KROPP; DANIEL SANROMA

410

How Do Global Positioning Systems, or GPS, Work?  

NSDL National Science Digital Library

A movie of students interviewing a NASA expert, who explains basic GPS principles. Simple, but clear description of how trilateration works with a two-dimensional model vs 3-D. Appropriate for the 6-8 grade range.

Nasa; Knockout, Video C.

411

Evaluating the velocity accuracy of an integrated GPS/INS system: Flight test results  

SciTech Connect

Verifying the velocity accuracy of a GPS receiver or an integrated GPS/INS system in a dynamic environment is a difficult proposition when many of the commonly used reference systems have velocity uncertainities of the same order of magnitude or greater than the GPS system. The results of flight tests aboard an aircraft in which multiple reference systems simultaneously collected data to evaluate the accuracy of an integrated GPS/INS system are reported. Emphasis is placed on obtaining high accuracy estimates of the velocity error of the integrated system in order to verify that velocity accuracy is maintained during both linear and circular trajectories. Three different reference systems operating in parallel during flight tests are used to independently determine the position and velocity of an aircraft in flight. They are a transponder/interrogator ranging system, a laser tracker, and GPS carrier phase processing. Results obtained from these reference systems are compared against each other and against an integrated real time differential based GPS/INS system to arrive at a set of conclusions about the accuracy of the integrated system.

Owen, T.E.; Wardlaw, R.

1991-12-31

412

Predicted solar flare activity for the 1990s - Possible effects on navigation systems  

SciTech Connect

The current solar cycle, which began in September 1986, may prove to be the highest ever, as measured by sunspot numbers and radio flux. The cycle's frequent and strong solar flare activity can be illustrated by the March 1989 episode, which caused many problems for navigation systems. Flares and the geomagnetic storms that sometimes accompany them can disrupt low-frequency systems such as Loran-C, as well as the satellite-borne GPS. Although the maximum of the solar cycle is expected during the first quarter of 1990, flare activity is likely to persist at high levels for a few years to follow. Geomagnetic activity may occur at any time in the cycle, and thus geomagnetic disruptions are possible at any point in the 1990s. 5 refs.

Kunches, J.M.; Hirman, J.W. (NOAA, Boulder, CO (USA))

1990-01-01

413

Predicted solar flare activity for the 1990s - Possible effects on navigation systems  

NASA Astrophysics Data System (ADS)

The current solar cycle, which began in September 1986, may prove to be the highest ever, as measured by sunspot numbers and radio flux. The cycle's frequent and strong solar flare activity can be illustrated by the March 1989 episode, which caused many problems for navigation systems. Flares and the geomagnetic storms that sometimes accompany them can disrupt low-frequency systems such as Loran-C, as well as the satellite-borne GPS. Although the maximum of the solar cycle is expected during the first quarter of 1990, flare activity is likely to persist at high levels for a few years to follow. Geomagnetic activity may occur at any time in the cycle, and thus geomagnetic disruptions are possible at any point in the 1990s.

Kunches, J. M.; Hirman, J. W.

414

Urban, Indoor and Subterranean Navigation Sensors and Systems (Capteurs et systemes de navigation urbains, interieurs et souterrains).  

National Technical Information Service (NTIS)

The NATO Research and Technology Organization (RTO) Research Task Group (RTG) on Urban, Indoor and Subterranean Navigation Sensors and Systems (SET-114, RTG-065) was formed to focus on how to enhance NATO military effectiveness through the improved use of...

2010-01-01

415

Rapid Retrieval and Assimilation of Ground Based GPS-Met Observations at the NOAA Forecast Systems Laboratory: Impact on Weather Forecasts  

NASA Astrophysics Data System (ADS)

This year, 2003, marks the tenth anniversary of ground-based Global Positioning System meteorology. GPS-Met as we now know it started in 1992 with the definition of the essential techniques to retrieve integrated (total column) precipitable water vapor (IPW) from zenith-scaled neutral atmospheric signal delays (Bevis et al., 1992). It culminated with the GPS/Storm experiment in 1993, which demonstrated the ability to make IPW measurements with about the predicted accuracy under warm-weather conditions (Rocken et al., 1995). Since then, most of the major advances in GPS-Met data processing have been in the form of improved mapping functions (Niell, 1996), the estimation of GPS signal delays in an absolute (Duan et al., 1996) versus a relative sense (Rocken et al., 1993), and improved GPS satellite orbit accuracy with reduced latency (Fang et al., 1998). Experiments with other GPS-Met data processing techniques, such as the estimation of line-of-sight GPS signal delays using a double-difference to zero-difference technique described by Alber et al. (2000) and Braun et al. (2001) are noted, but lingering questions about the validity of this approach (Gutman, 2002), and not the potential value of a slant-path measurements per se, (as enumerated by MacDonald and Xie, 2001 or Ha et al., 2002) have thus far precluded its routine implementation at the National Oceanic and Atmospheric Administration Forecast Systems Laboratory (NOAA/FSL). Since 1994, NOAA/FSL has concentrated on evaluating the scientific and engineering bases of ground-based GPS-Met and assessing its utility for operational weather forecasting, climate monitoring, satellite calibration and validation, and improved differential GPS positioning and navigation. The term “rapid” in the title of this paper is defined as “available in time to be used for a specific application.” The requirement for high accuracy GPS-Met retrievals with lower latency is primarily driven by two factors: the trend toward shorter forecast cycles and higher spatial resolution in mesoscale numerical weather prediction (NWP) models, and the use by weather forecasters in subjective forecasting and/or model verification. GPS and ancillary surface meteorological observations, and improved satellite orbits, must be available on demand. Data processing hardware and techniques must provide GPS-Met retrievals in sufficient time to be assimilated into the current model cycle. Model data assimilation techniques must minimize the errors in estimating the initial state of a numerical forecast that come from spatial and temporal aliasing when interpolating discrete observations into an "analysis increment" field. While more GPS-Met retrievals can minimize horizontal aliasing, they can do little to minimize vertical aliasing that comes from assimilating any vertically integrated quantity (e.g. satellite radiances, zenith tropospheric signal delays, or GPS-IPW retrievals) into an NWP model. This is primarily because the forecast background error at a discrete vertical level must be estimated from the difference between observed and forecast integrated quantities. Absent the development of a new observing system or measurement technique, we must rely on improved data assimilation techniques, coupled with the more efficient use of complementary observing systems, to improve the three-dimensional description of moisture in the atmosphere. NOAA/FSL has conducted data denial experiments since 1998 to determine the statistical impact that GPS-IPW retrievals have on 3-hour moisture and precipitation forecasts in the central United States. Results from 5-years of experiments indicate more or less continuous improvement in forecast skill as the GPS-Met network expands. Improvements are observed in relative humidity forecast accuracy at all levels below 500 hPa, and all precipitation levels above “trace”. The impact steadily decreases with the length of the forecast; it is usually substantial from 0-3 hours, and negligible from 6-12 hours. The largest impacts usually occur during active weather

Gutman, S.

2003-04-01

416

Near real-time GPS applications for tsunami early warning systems  

NASA Astrophysics Data System (ADS)

GPS (Global Positioning System) technology is widely used for positioning applications. Many of them have high requirements with respect to precision, reliability or fast product delivery, but usually not all at the same time as it is the case for early warning applications. The tasks for the GPS-based components within the GITEWS project (German Indonesian Tsunami Early Warning System, Rudloff et al., 2009) are to support the determination of sea levels (measured onshore and offshore) and to detect co-seismic land mass displacements with the lowest possible latency (design goal: first reliable results after 5 min). The completed system was designed to fulfil these tasks in near real-time, rather than for scientific research requirements. The obtained data products (movements of GPS antennas) are supporting the warning process in different ways. The measurements from GPS instruments on buoys allow the earliest possible detection or confirmation of tsunami waves on the ocean. Onshore GPS measurements are made collocated with tide gauges or seismological stations and give information about co-seismic land mass movements as recorded, e.g., during the great Sumatra-Andaman earthquake of 2004 (Subarya et al., 2006). This information is important to separate tsunami-caused sea height movements from apparent sea height changes at tide gauge locations (sensor station movement) and also as additional information about earthquakes' mechanisms, as this is an essential information to predict a tsunami (Sobolev et al., 2007). This article gives an end-to-end overview of the GITEWS GPS-component system, from the GPS sensors (GPS receiver with GPS antenna and auxiliary systems, either onshore or offshore) to the early warning centre displays. We describe how the GPS sensors have been installed, how they are operated and the methods used to collect, transfer and process the GPS data in near real-time. This includes the sensor system design, the communication system layout with real-time data streaming, the data processing strategy and the final products of the GPS-based early warning system components.

Falck, C.; Ramatschi, M.; Subarya, C.; Bartsch, M.; Merx, A.; Hoeberechts, J.; Schmidt, G.

2010-02-01

417

Use of Loran-C navigation system to accurately determine sampling site location in an above ground cooling reservoir  

SciTech Connect

Environmental monitoring programs often require accurate determination of sampling site locations in aquatic environments. This is especially true when a {open_quotes}picture{close_quotes} of high resolution is needed for observing a changing variable in a given area and location is assumed to be important to the distribution of that variable. Sample site location can be difficult if few visible land marks are available for reference on a large body of water. The use of navigational systems such as Global Positioning System (GPS) and its predecessor, Loran-C, provide an excellent method for sample site location. McFarland (1992) discusses the practicality of GPS for location determination. This article discusses the use of Loran-C in a sampling scheme implemented at the South Texas Project Electrical Generating Station (STPEGS), Wadsworth, Texas.

Lockwood, R.E. [Houston Lighting and Power Company, Wadsworth, TX (United States); Blankinship, D.R. [Texas A& M Univ., College Station, TX (United States)

1994-12-31

418

Technical Report of National Aerospace Laboratory. Development of Carrier-Phase and DGPS/INS Hybrid Navigation Algorithm.  

National Technical Information Service (NTIS)

To enable precision approach and landing navigation, a carrier-phase DGPS/INS hybrid navigation system was developed characterized by the primary use of a GPS carrier-phase rather than a GPS pseudorange. Half the advantages of this system are derived from...

M. Harigae M. Murata

2000-01-01

419

Context-Aware Indoor Navigation  

Microsoft Academic Search

Over the past few years, several technological advances have been made to enable locating people in indoor settings, where\\u000a way finding is something we do on a daily basis. In a similar way as it happened with GPS and today’s popular outdoor navigation\\u000a systems, indoor navigation is set to become one of the first, truly ubiquitous services that will make

Fernando Lyardet; Diego Wong Szeto; Erwin Aitenbichler

2008-01-01

420

Design of integrated electronic chart pocket navigator system (PNS) and application for passage ship auto-track  

NASA Astrophysics Data System (ADS)

With the development of hydrographical work and information techniques, digital charts are more and more popular in maritime applications, and an embedded product--PDA (personal digital assistant) is widely used in navigation for its smallness and portability. However, there is lack of PDA-based product which can provide integrated data management, real-time alternate display and ship auto-track application based on traditional paper chart and s-57 ENC. Aiming at this, some new techniques and algorithms including integrated spatial data management and display mode for ENC and paper chart, multi-scale data organization, embedded chart navigation method based on GPS are presented. And the integrated electronic chart pocket navigator system (PNS) based on PDA was developed.

Sui, Haigang; Xiao, Jinghuan; Zhang, Anming; Luo, Jie

2007-11-01

421

The RMI Space Weather and Navigation Systems (SWANS) Project  

NASA Astrophysics Data System (ADS)

The SWANS (Space Weather and Navigation Systems) research and development project (http://swans.meteo.be) is an initiative of the Royal Meteorological Institute (RMI) under the auspices of the Belgian Solar-Terrestrial Centre of Excellence (STCE). The RMI SWANS objectives are: research on space weather and its effects on GNSS applications; permanent mon-itoring of the local/regional geomagnetic and ionospheric activity; and development/operation of relevant nowcast, forecast, and alert services to help professional GNSS/GALILEO users in mitigating space weather effects. Several SWANS developments have already been implemented and available for use. The K-LOGIC (Local Operational Geomagnetic Index K Calculation) system is a nowcast system based on a fully automated computer procedure for real-time digital magnetogram data acquisition, data screening, and calculating the local geomagnetic K index. Simultaneously, the planetary Kp index is estimated from solar wind measurements, thus adding to the service reliability and providing forecast capabilities as well. A novel hybrid empirical model, based on these ground-and space-based observations, has been implemented for nowcasting and forecasting the geomagnetic index, issuing also alerts whenever storm-level activity is indicated. A very important feature of the nowcast/forecast system is the strict control on the data input and processing, allowing for an immediate assessment of the output quality. The purpose of the LIEDR (Local Ionospheric Electron Density Reconstruction) system is to acquire and process data from simultaneous ground-based GNSS TEC and digital ionosonde measurements, and subsequently to deduce the vertical electron density distribution. A key module is the real-time estimation of the ionospheric slab thickness, offering additional infor-mation on the local ionospheric dynamics. The RTK (Real Time Kinematic) status mapping provides a quick look at the small-scale ionospheric effects on the RTK precision for several GPS stations in Belgium. The service assesses the effect of small-scale ionospheric irregularities by monitoring the high-frequency TEC rate of change at any given station. This assessment results in a (colour) code assigned to each station, code ranging from "quiet" (green) to "extreme" (red) and referring to the local ionospheric conditions. Alerts via e-mail are sent to subscribed users when disturbed conditions are observed. SoDIPE (Software for Determining the Ionospheric Positioning Error) estimates the position-ing error due to the ionospheric conditions only (called "ionospheric error") in high-precision positioning applications (RTK in particular). For each of the Belgian Active Geodetic Network (AGN) baselines, SoDIPE computes the ionospheric error and its median value (every 15 min-utes). Again, a (colour) code is assigned to each baseline, ranging from "nominal" (green) to "extreme" (red) error level. Finally, all available baselines (drawn in colour corresponding to error level) are displayed on a map of Belgium. The future SWANS work will focus on regional ionospheric monitoring and developing various other nowcast and forecast services.

Warnant, Rene; Lejeune, Sandrine; Wautelet, Gilles; Spits, Justine; Stegen, Koen; Stankov, Stan

422

An Expert System and Tutor for Maritime Navigation Rules  

Microsoft Academic Search

The Navigation Rules Expert System (NRES) is a CLIPS-based implementation of the International and Inland Maritime Navigation Rules (COMDTINST M16672.2C) to assist mariners. NRES functionality is divided into two components, the Mariner-Assistance Module and the Student-Tutor Module. The Mariner-Assistance Module (MAM) is designed for use in real-time operations to assist mariners in correctly determining both the maritime situation and the

LT Sharif Calfee

423

The Effect of Helicopter Rotors on GPS Signal Reception  

NASA Astrophysics Data System (ADS)

This paper presents the results of an experiment to investigate the impact of helicopter rotor blades on GPS signal reception. An offshore transport helicopter was equipped with a measurement system including a TSO-C129 compliant receiver and a custom research receiver. GPS signals passing through rotor discs of this aircraft were found to suffer a reduction in received signal strength, leading to potential navigation and RAIM availability concerns. The phenomenon will vary between installations and receiver types. Test procedures to identify the occurrence of the phenomenon in operational GPS installations are presented, together with possible in-service monitoring programs to assess the impact on the navigation function.

Brodin, Gary; Cooper, John; Walsh, David; Stevens, Jeff

2005-09-01

424

Absolute Positioning by Collecting Global Positioning System (GPS) Data along Short Baselines.  

National Technical Information Service (NTIS)

This report addresses the problem of determining absolute positions (longitude and latitude) from Global Positioning System (GPS) data in the presence of Selective Availability (SA). The SA-epsilon effect can be avoided if one can wait until corrected or ...

B. R. Hermann A. G. Evans

1993-01-01

425

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

SciTech Connect

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. 59 refs.

Bevis, M.; Businger, S.; Herring, T.A.; Rocken, C.; Anthes, R.A.; Ware, R.H. (North Carolina State Univ., Raleigh (United States) MIT, Cambridge, MA (United States) Univ. Navstar Consortium, Boulder, CO (United States) Univ. Corp. for Atmospheric Research, Boulder, CO (United States))

1992-10-01

426

Autonomous navigation of USAF spacecraft  

NASA Astrophysics Data System (ADS)

Observations from several medium-accuracy space sensors, such as the existing telescopic space sextant are compared with those of future matrix-type sensors. The large field of view of matrix sensors should permit determining the Earth horizon to approximately an order of magnitude better than current infrared sensors by observing atmospheric refraction of stellar light. This horizon determination will give the matrix sensors an accuracy of less than 1 km. The limiting factor in Earth-horizon determination is the modeling of atmospheric refraction effects. For high-accuracy requirements (100 meters or less), the Global Positioning System (GPS) offers the only near-term solution. A relative navigation technique using range and Doppler data is proposed for autonomous navigation of the GPS satellites. The navigation accuracy of this technique is evaluated by considering covariance analysis and by processing corrupted data through a reduced-order onboard sequentially partitioned algorithm. The algorithm is stable and for the GPS system produces in-plane accuracy of 40 meters over twenty days. However, out-of-plane motion is shown to be unobservable in the GPS-to-GPS tracking mode, and errors of up to 1.5 km over 60 days are experienced. For this reason, a supplemental transmitter on the ground or in a different orbit is recommended.

Ferguson, J. R., Jr.

427

INS\\/GPS Integration: Global Observability Analysis  

Microsoft Academic Search

Observability is an important aspect of the state-estimation problem in the integration of the inertial navigation system (INS) and the Global Positioning System (GPS) as it determines the existence and nature of solutions. In most previous research, conservative observability concepts, e.g., local observability and linear observability, have extensively been used to locally characterize the estimability properties. In this paper, a

Yonggang Tang; Yuanxin Wu; Meiping Wu; Wenqi Wu; Xiaoping Hu; Lincheng Shen

2009-01-01

428

GPS and Galileo Performance Evaluations for Multiple Reference Network Real-Time Positioning  

Microsoft Academic Search

The European Galileo system and the modernization of the current Global Positioning System (GPS) will substantially increase the available signals to Global Navigation Satellite Systems (GNSS) users. Past simulation studies have shown that Galileo performs better than GPS for high ionospheric conditions and for medium length baselines for the Single Reference Station (SRS) approach. When the baseline increases beyond 30

Seema Phalke; M. Elizabeth Cannon

429

Real-time tracking management system using GPS, GPRS and Google earth  

Microsoft Academic Search

Due to the high cost of fossil-based energy, several methods are proposed to reduce the usage of the energy in logistics and fleet management to be even more. GPS tracking system is a common approach to get vehicle location information in real-time for fleet planning. We proposed a GPS tracking system called Goo-Tracking that is composed of commodity hardware, open

Noppadol Chadil; Apirak Russameesawang; Phongsak Keeratiwintakorn

2008-01-01

430

Development of a low-cost integrated GPS\\/IMU system  

Microsoft Academic Search

This paper describes the development of a low-cost and small size integrated Global Positioning System (GPS)\\/inertial measurement unit (IMU). The developed strapdown Attitude and Heading Reference System (AHRS) is capable of providing attitude and heading accuracy at ±0.2 and ±0.4 degrees, respectively. The prototype of low-cost integrated GPS\\/IMU can give positioning accuracy of 10 metres

Xiufeng He; Yongqi Chen; Jianye Liu

1998-01-01

431

Example of a mixed-signal Global Positioning System (GPS) receiver using MCM-L packaging  

Microsoft Academic Search

Under an Advanced Research Projects Agency program (NRaD contract N66001-89-C-0104), a fully functional Global Positioning System (GPS) receiver using Laminated Multichip Modules (MCM-L's) was developed. Although many facets of GPS are of interest, this paper will use this particular module design as an example of a more generic mixed-signal (i.e., containing both analog and digital electronic elements) system, concentrating on

P. J. Zabinski; B. K. Gilbert; P. J. Zucarelli; D. V. Weninger; T. W. Keller

1995-01-01

432

Borehole survey system utilizing strapdown inertial navigation  

SciTech Connect

A signal processing method is described for use in borehole surveys, consisting of: (a) transforming the acceleration signals in the first coordinate system to obtain inertial signals representative of movement of the probe in a second coordinate system that is fixed relative to the earth, the inertial signals in the second coordinate system including probe velocity signals; (b) generating a signal representative of the amount of cable being fed into the entrance opening of the borehole; (c) processing the signal representative of the amount of cable being feed into the entrance opening of the borehole; (d) transforming the inertial signals representative of movement of the probe in the second coordinate system into inertial signals representative of movement of the probe in the first coordinate system; (e) combining the signal representative of the progress of the probe along the borehole with the inertial signals representative of movement of the probe in the first coordinate system to obtain error signals; (f) transforming the error signals into the second coordinate system to obtain error correction signals; (g) combining the error correction signals with the inertial signals representative of movement of the probe in the second coordinate system to obtain corrected probe velocity signals; and (h) integrating the corrected probe velocity signals to obtain signals representative of the course of the borehole relative to the second coordinate system.

Hulsing, R.H.

1989-03-14

433

A stereo camera system for autonomous maritime navigation (AMN) vehicles  

Microsoft Academic Search

Spatial Integrated System (SIS), Rockville, Maryland, in collaboration with NSWC Combatant Craft Division (NSWCCD), is applying 3D imaging technology, artificial intelligence, sensor fusion, behaviors-based control, and system integration to a prototype 40 foot, high performance Research and Development Unmanned Surface Vehicle (USV). This paper focus on the developments of the stereo camera system in the USV navigation that currently consists

Weihong Zhang; Ping Zhuang; Les Elkins; Rick Simon; David Gore; Jeff Cogar; Kevin Hildebrand; Steve Crawford; Joe Fuller

2009-01-01

434

Overview of how the Global Positioning System (GPS) is used to study earthquakes  

NSDL National Science Digital Library

This module allows students to interactively explore the use of the Southern California Integrated GPS Network (SCIGN) and its data in earthquake studies. The four major sections, Plate Tectonics, Earthquakes, Global Positioning Systems (GPS), and Space Technology at Work, include background material and activities; the first three sections focus primarily on introducing satellite technology and tectonic phenomena, and the final section serves to integrate knowledge learned in the first three by allowing students to use real SCIGN data in their investigations into plate tectonics, earthquakes, and GPS.

Glasscoe, Maggie

435

Robust GPS autonomous signal quality monitoring  

NASA Astrophysics Data System (ADS)

The Global Positioning System (GPS), introduced by the U.S. Department of Defense in 1973, provides unprecedented world-wide navigation capabilities through a constellation of 24 satellites in global orbit, each emitting a low-power radio-frequency signal for ranging. GPS receivers track these transmitted signals, computing position to within 30 meters from range measurements made to four satellites. GPS has a wide range of applications, including aircraft, marine and land vehicle navigation. Each application places demands on GPS for various levels of accuracy, integrity, system availability and continuity of service. Radio frequency interference (RFI), which results from natural sources such as TV/FM harmonics, radar or Mobile Satellite Systems (MSS), presents a challenge in the use of GPS, by posing a threat to the accuracy, integrity and availability of the GPS navigation solution. In order to use GPS for integrity-sensitive applications, it is therefore necessary to monitor the quality of the received signal, with the objective of promptly detecting the presence of RFI, and thus provide a timely warning of degradation of system accuracy. This presents a challenge, since the myriad kinds of RFI affect the GPS receiver in different ways. What is required then, is a robust method of detecting GPS accuracy degradation, which is effective regardless of the origin of the threat. This dissertation presents a new method of robust signal quality monitoring for GPS. Algorithms for receiver autonomous interference detection and integrity monitoring are demonstrated. Candidate test statistics are derived from fundamental receiver measurements of in-phase and quadrature correlation outputs, and the gain of the Active Gain Controller (AGC). Performance of selected test statistics are evaluated in the presence of RFI: broadband interference, pulsed and non-pulsed interference, coherent CW at different frequencies; and non-RFI: GPS signal fading due to physical blockage and multipath. Results are presented which verify the effectiveness of these proposed methods. The benefits of pseudolites in reducing service outages due to interference are demonstrated. Pseudolites also enhance the geometry of the GPS constellation, improving overall system accuracy. Designs for pseudolites signals, to reduce the near-far problem associated with pseudolite use, are also presented.

Ndili, Awele Nnaemeka

436

Simple nonlinear systems and navigating catastrophes  

NASA Astrophysics Data System (ADS)

Tipping points are a common occurrence in complex adaptive systems. In such systems feedback dynamics strongly influence equilibrium points and they are one of the principal concerns of research in this area. Tipping points occur as small changes in system parameters result in disproportionately large changes in the global properties of the system. In order to show how tipping points might be managed we use the Maximum Entropy (MaxEnt) method developed by Jaynes to find the fixed points of an economic system in two different ways. In the first, economic agents optimise their choices based solely on their personal benefits. In the second they optimise the total benefits of the system, taking into account the effects of all agent's actions. The effect is to move the game from a recently introduced dual localised Lagrangian problem to that of a single global Lagrangian. This leads to two distinctly different but related solutions where localised optimisation provides more flexibility than global optimisation. This added flexibility allows an economic system to be managed by adjusting the relationship between macro parameters, in this sense such manipulations provide for the possibility of "steering" an economy around potential disasters.

Harré, Michael S.; Atkinson, Simon R.; Hossain, Liaquat

2013-06-01

437

The future of GPS-based electric power system measurements, operation and control  

SciTech Connect

Much of modern society is powered by inexpensive and reliable electricity delivered by a complex and elaborate electric power network. Electrical utilities are currently using the Global Positioning System-NAVSTAR (GPS) timekeeping to improve the network`s reliability. Currently, GPS synchronizes the clocks on dynamic recorders and aids in post-mortem analysis of network disturbances. Two major projects have demonstrated the use of GPS-synchronized power system measurements. In 1992, the Electric Power Research Institute`s (EPRI) sponsored Phase Measurements Project used a commercially available Phasor Measurements Unit (PMU) to collect GPS-synchronized measurements for analyzing power system problems. In 1995, Bonneville Power Administration (BPA) and Western Area Power Administration (WAPA) under DOE`s and EPRI`s sponsorship launched the Wide Area Measurements (WAMS) project. WAMS demonstrated GPS-synchronized measurements over a large area of their power networks and demonstrated the networking of GPS-based measurement systems in BPA and WAPA. The phasor measurement technology has also been used to conduct dynamic power system tests. During these tests, a large dynamic resistor was inserted to simulate a small power system disturbance.

Rizy, D.T. [Oak Ridge National Lab., TN (United States); Wilson, R.E. [Western Area Power Administration, Golden, CO (United States); Martin, K.E.; Litzenberger, W.H. [Bonneville Power Administration, Portland, OR (United States); Hauer, J.F. [Pacific Northwest National Lab., Richland, WA (United States); Overholt, P.N. [Dept. of Energy, Washington, DC (United States); Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)

1998-11-01

438

Navigating at the Speed of Satellites  

NSDL National Science Digital Library

For thousands of years, navigators have looked to the sky for direction. Today, celestial navigation has simply switched from using natural objects to human-created satellites. A constellation of satellites, called the Global Positioning System, and hand-held receivers allow for very accurate navigation. In this lesson, students investigate the fundamental concepts of GPS technology â trilateration and using the speed of light to calculate distances.

Integrated Teaching And Learning Program

439

Evolvable Hardware: A Robot Navigation System Testbed  

Microsoft Academic Search

Recently there has been great interest in the design and study of evolvable systems based on Artificial Life principles in\\u000a order to monitor and control the behavior of physically embedded systems such as mobile robots, plants and intelligent home\\u000a devices. At the same time new integrated circuits calledsoftware-reconfigurable devices have been introduced which are able to adapt their hardware almost

Didier Keymeulen; Masaya Iwata; Kenji Konaka; Yasuo Kuniyoshi; Tetsuya Higuchi

1998-01-01

440

Global positioning system pseudolite-based relative navigation.  

SciTech Connect

Though the Global Positioning System has revolutionized navigation in the modern age, it is limited in its capability for some applications because an unobstructed line of sight to a minimum of four satellites is required. One way of augmenting the system in small areas is by employing pseudolites to broadcast additional signals that can be used to improve the user's position solution. At the Navigation Systems Testing Laboratory (NSTL) at NASA's Johnson Space Center in Houston, TX, research has been underway on the use of pseudolites to perform precision relative navigation. Based on the findings of previous research done at the NSTL, the method used to process the pseudolite measurements is an extended Kalman filter of the double differenced carrier phase measurements. By employing simulations of the system, as well as processing previously collected data in a real time manner, sub-meter tracking of a moving receiver with carrier phase measurements in the extended Kalman filter appears to be possible.

Monda, Eric W. (University of Texas, Austin, TX)

2004-03-01

441

A simplified vibrotactile navigation system for sightseeing  

Microsoft Academic Search

We propose a new sightseeing support system that allows users to focus on environmental information at tourist sites. The main aim of our project is to enable users to recognize the physical positional relation between their current position and their destination. The user moves our device in a 360-degree circle around his body to perceive direction and distance to the

Yuji Tamiya; Takuya Nojima

2011-01-01

442

Flight tests of GPS/GLONASS precise positioning versus dual frequency KGPS profile  

NASA Astrophysics Data System (ADS)

The benefits of combined use of the GLONASS and GPS navigation satellite constellations have become obvious for applications such as open-cast mining operations and highly dynamic vehicles such as spaceplanes. Moreover, using GLONASS satellites in addition to GPS is useful for long baseline applications since it increases the numbers of satellites in common view. Japan's National Aerospace Laboratory (NAL) has been conducting feasibility studies using combined GPS/GLONASS positioning for spaceplane landing systems and the precise navigation of stratospheric airships. This paper presents the results of the first Japanese kinematic GPS/GLONASS flight test. In the test, the difference in estimated position between dual frequency GPS and single frequency GPS/GLONASS systems was found to be within a few centimeters, indicating that GLONASS carrier phase ambiguities were correctly resolved. To demonstrate the benefits of combining GLONASS with GPS navigation, an on-the-fly (OTF) test of instantaneous ambiguity resolution with a 30 degree cutoff angle was performed. The OTF performance of the combined GPS/GLONASS system was found to be similar to that of a GPS system with a cutoff angle of 10 degrees, showing that augmentation of GPS with GLONASS will be useful for highly dynamic vehicle applications.

Tsujii, T.; Harigae, M.; Inagaki, T.; Kanai, T.

2000-10-01

443

A System to Produce Precise Global GPS Network Solutions for all Geodetic GPS Stations in the World  

NASA Astrophysics Data System (ADS)

We have developed an end-to-end system that automatically seeks and routinely retrieves geodetic GPS data from ~5000 stations (currently) around the globe, reduces the data into unique, daily global network solutions, and produces high precision time series for station coordinates ready for time-series analysis, geophysical modeling and interpretation. Moreover, “carrier range” data are produced for all stations, enabling epoch-by-epoch tracking of individual station motions by precise point positioning for investigation of sub-daily processes, such as post-seismic after-slip and ocean tidal loading. Solutions are computed in a global reference frame aligned to ITRF, and optionally in user-specified continental-scale reference frames that can filter out common-mode signals to enhance regional strain anomalies. We describe the elements of this system, the underlying signal processing theory, the products, operational statistics, and scientific applications of our system. The system is fundamentally based on precise point positioning using JPL's GIPSY OASIS II software, coupled with ambiguity resolution and a global network adjustment of ~300,000 parameters per day using our newly developed Ambizap3 software. The system is designed to easily and efficiently absorb stations that deliver data very late, by recycling prior computations in the network adjustment, such that the resulting network solution is identical to starting from scratch. Thus, it becomes possible to trawl continuously the Internet for late arriving data, or for newly discovered data, and seamlessly update all GPS station time series using the new information content. As new stations are added to the processing archive, automated e-mail requests are made to H.-G. Scherneck's server at Chalmers University to compute ocean loading coefficients used by the station motion model. Rinex file headers are parsed and compared with alias tables in order to infer the correct receiver type and antenna/radome phase calibrations to apply to the data. Strict quality control is implemented at all levels of the system, with the exception that time series analysis is not used to remove outliers, as that could inhibit discovery of unusual site motions. Implemented on a 100-cpu cluster with custom server-client software, the system in summer 2010 computed from scratch the entire time series for ~7000 stations from 1996-2010 within 2 months. The latest GPS orbits from JPL's “FlinnR” re-analysis was applied together with transformations into the IGS05 reference frame. Custom reference frames were applied for analysis of station motions with respect to stable North America. Results from this re-analysis will be presented in terms of time series quality, computation time, and scientific products.

Blewitt, G.; Kreemer, C. W.

2010-12-01

444

Gyro and Accelerometer Based Navigation System for a Mobile Autonomous Robot.  

National Technical Information Service (NTIS)

A navigation system for a mobile autonomous robot is presented. The navigation system is based upon a directional gyroscope and a single axis accelerometer which enables a robot to navigate independent of wheel optical shaft encoders and other commonly us...

R. J. Bloom W. J. Ramey

1985-01-01

445

An Indoor Navigation System for the Visually Impaired  

PubMed Central

Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user's trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

Guerrero, Luis A.; Vasquez, Francisco; Ochoa, Sergio F.

2012-01-01

446

Design and implementation of webGIS-based GPS vehicle monitoring system  

Microsoft Academic Search

This paper develops a WebGIS-based GPS vehicle monitoring system with typical three-tier application architecture of B\\/S pattern.\\u000a It provides ordinary registered users with a valid and convenient means to get access to real-time GPS location information\\u000a of certain moving vehicles at any place, and further offers a powerful tool for super users to manage user information and\\u000a remotely monitor those

Cheng Qimin; Yang Chongjun; Shao Zhenfeng; Liu Donglin; Gao Liang

2004-01-01

447

Installation and Evaluation of Lorac Precise Navigation System.  

National Technical Information Service (NTIS)

A navigation system was established on Monterey Bay using the LORAC principle of phase-comparison. It is intended primarily for use in ocean sciences research within a 25 mile radius of Moss Landing, California. The system offers the capability of repeati...

R. E. Shrum

1968-01-01

448

Position control of a surgical robot by a navigation system  

Microsoft Academic Search

In orthopaedic surgery, the development of computer based new technologies such as navigation systems and robotics will facilitate more precise, reproducible results of surgical interventions. There are already commercial systems available for clinical use which, however, still have some limitations and drawbacks. Most of them can only be applied in a very narrow application range and it is not possible

P. Knappe; I. Gross; S. Pieck; J. Wahrburg; S. Kuenzler; F. Kerschbaumer

2003-01-01

449

Taux: A System for Evaluating Sound Feedback in Navigational Tasks  

ERIC Educational Resources Information Center

|This thesis presents the design and development of an evaluation system for generating audio displays that provide feedback to persons performing navigation tasks. It first develops the need for such a system by describing existing wayfinding solutions, investigating new electronic location-based methods that have the potential of changing these…

Lutz, Robert J.

2008-01-01

450

Navigation and mobile security system of intelligent security robot  

Microsoft Academic Search

We have recently developed a software architecture in intelligent security robot (ISR). Sensor data, motion planning, motion control, vision system, remote control and other parts of software can all communicate with each other through kernel system. We also discuss the modes and distance of obstacle avoidance that influence in the pathway of obstacle avoidance. In order to navigate ISR to

R. C. Luo; P. K. Wang; T. Y. Hsu; T. Y. Lin

2005-01-01

451

A Behavior-Based System For Off-Road Navigation  

Microsoft Academic Search

In this paper, we describe a core system for autonomous navigation in outdoor natural ter- rain. The system consists of three parts: a perception module which processes range images to identify untraversable regions of the terrain, a local map management module which main- tains a representation of the environment in the vicinity of the vehicle, and a planning module which

D. Langer; J. K. Rosenblatt; M. Hebert

1994-01-01

452

EXTRACTING LANDMARKS FOR CAR NAVIGATION SYSTEMS USING EXISTING GIS DATABASES AND LASER SCANNING  

Microsoft Academic Search

Today's car navigation systems provide driving instructions in the form of maps, pictograms, and spoken language. However, they are so far not able to support landmark-based navigation, which is the most natural navigation concept for humans and which also plays an important role for upcoming personal navigation systems. In order to provide such a navigation, the rst step is to

C. Brenner; B. Elias

2003-01-01

453

Integration of ultraviolet sensor and X-ray detector for navigation satellite orbit estimation  

Microsoft Academic Search

In recent years, X-ray navigation (XNAV) has become of great interest for spacecraft autonomous navigation. The XNAV system can be used as an augmentation to the current navigation capability or as a backup to the Global Position System (GPS) and the deep space network (DSN). In this paper, the XNAV system is used to augment the ultraviolet (UV) sensor based

Li Qiao; Jianye Liu; Guanglou Zheng; Zhi Xiong

2008-01-01

454

GPS-GIS INTEGRATED SYSTEM FOR ELECTROMAGNETIC POLLUTION  

Microsoft Academic Search

In these last years employment and spreading of GPS real-time kinematic techniques is greatly improved. Its application field is extended from traditional topographic surveys to environmental applications. In this work a monitoring project of electromagnetic pollution is shown; this project has been carried out in order to realize an infrastructure of meas urement, transmissions, elaboration and management of surveyed data.

A. Ammoscato; R. Corsale; G. Dardanelli; A. Scianna; B. Villa

455

The Nuclear Detonation Detection System on the GPS satellites  

SciTech Connect

This article begins with a historical perspective of satellite usage in monitoring nuclear detonations. Current capabilities of the 24 GPS satellites in detecting the light, gamma rays, x-rays and neutrons from a nuclear explosion are described. In particular, an optical radiometer developed at Sandia National Laboratories is characterized. Operational information and calibration procedures are emphasized.

Higbie, P.R. [Los Alamos National Lab., NM (United States); Blocker, N.K. [Sandia National Labs., Albuquerque, NM (United States)

1993-07-27

456

Georeferencing for UAV navigation using environmental classification  

Microsoft Academic Search

A UAV navigation system relying on GPS is vulnerable to signal failure, making a drift free backup system necessary. We introduce a vision based geo-referencing system that uses pre-existing maps to reduce the long term drift. The system classifies an image according to its environmental con- tent and thereafter matches it to an environmentally classified map over the operational area.

Fredrik Lindsten; Jonas Callmer; Henrik Ohlsson; David Törnqvist; Thomas B. Schön; Fredrik Gustafsson

2010-01-01

457

Conceptual approaches to avian navigation systems.  

PubMed

The general basis of migratory orientation in birds is most probably an endogenous time-and-direction programme. Directions are selected with respect to celestial as well as geomagnetic clues. These clues appear to be integrated within a system that profits from the special advantages of either kind of environmental signal, and thereby can cope with their limitations. Using these clues, and following a genetically determined intended direction (or sequence of directions) over a genetically determined period of time, a bird may reach a larger population-specific area. However, it will hardly be able to find a particular location, such as, for instance, its previous breeding site. Homing to a familiar site over several hundred kilometers of unfamiliar terrain is substantially based on the smelling of atmospheric trace compounds. At shorter distances from home, orientation by means of--presumably visual--familiar landmarks completes the repertoire of mechanisms guiding a bird back home. These mechanisms are considered to be based on different kinds of 'maps' and 'compasses'. Conceptual approaches to the properties of an 'olfactory map' have as yet only reached an early state of speculation. PMID:1838512

Wallraff, H G

1991-01-01

458

Image-based 3D scene analysis for navigation of autonomous airborne systems  

NASA Astrophysics Data System (ADS)

In this paper we describe a method for automatic determination of sensor pose (position and orientation) related to a 3D landmark or scene model. The method is based on geometrical matching of 2D image structures with projected elements of the associated 3D model. For structural image analysis and scene interpretation, a blackboard-based production system is used resulting in a symbolic description of image data. Knowledge of the approximated sensor pose measured for example by IMU or GPS enables to estimate an expected model projection used for solving the correspondence problem of image structures and model elements. These correspondences are presupposed for pose computation carried out by nonlinear numerical optimization algorithms. We demonstrate the efficiency of the proposed method by navigation update approaching a bridge scenario and flying over urban area, whereas data were taken with airborne infrared sensors in high oblique view. In doing so we simulated image-based navigation for target engagement and midcourse guidance suited for the concepts of future autonomous systems like missiles and drones.

Jaeger, Klaus; Bers, Karlheinz

2001-10-01

459

The navigation of navigation satellites  

Microsoft Academic Search

The methods used in computing precise satellite coordinates and ephemerides for navigation satellites are described, together with the way in which these methods are applied to the computation of the Transit and GPS ephemerides. The method used for precise orbit determination is based on a two-stage computational procedure: (1) numerical integration of an acceleration model, leading to a 'computed orbit',

V. Ashkenazi; T. Moore

1986-01-01

460

A Navigator Decision Support System in Planning a Safe Trajectory  

Microsoft Academic Search

The problem of safe and effective, i.e. economical handling of a sea-going vessel is connected with collision avoidance maneuvers and voyage planning (route planning) of vessels. In both cases various methods and tools are used for analyzing and assessing a navigational situation as well as maneuver planning and execution. Such actions are aimed at building systems of decision support and

Zbigniew PIETRZYKOWSKI; Jaroslaw CHOMSKI

461

Research on the dynamic error of strapdown inertial navigation system  

Microsoft Academic Search

Researching on the static error of strapdown inertial navigation system (SINS) plays a great role in the past. This is mainly due to the complex mathematical model for dynamic error of SINS. It is hard to do the error analysis from the perspective of the number. So in most cases, the static model owns the better position in the research

Yanling Hao; Jing Gong; Wei Gao; Liang Li

2008-01-01

462

PERFORMANCE ASSESSMENT OF A MULTU-SENSOR PERSONAL NAVIGATOR SUPPORTED BY AN ADAPTIVE KNOWLEDGE BASED SYSTEM  

Microsoft Academic Search

The prototype of a personal navigator to support navigation and tracking of military and rescue ground personnel has been developed at The Ohio State University Satellite Positioning and Inertial Navigation (SPIN) Laboratory. This paper provides a review of the navigation techniques suitable for personal navigation and follows with design, implementation and performance assessment of the system prototype, with a special

D. A. Grejner-Brzezinska; C. K. Toth

463

Airport Surface RNP (Required Navigation Performance) - Implications for GNSS  

Microsoft Academic Search

One of the anticipated applications of Global Navigation Satellite Systems (GNSS), including the Global Positioning System (GPS), is aircraft navigation on the airport surface. With the implementation of local area differential GNSS, technology will be available to enable aircraft to obtain accurate position information when

Rick Cassell; Scott Bradfield; Alex Smith

1997-01-01

464

Constellation Observing System for Meteorology, Ionosphere and Climate: Operational Demonsration of GPS Occultation from Space  

NASA Astrophysics Data System (ADS)

COSMIC is the Constellation Observing System for Meteorology, Ionosphere and Climate, a joint U.S.-Taiwan project. The scientific foundation for COSMIC is the radio occultation (limb sounding) technique which was developed by the Jet Propulsion Laboratory (JPL) and Stanford University in the late 1960s to study planetary atmospheres. By placing an advanced GPS receiver developed by JPL on each of six micro-satellite, COSMIC will collect approximately 3,000 GPS radio occultation soundings per day, distributed uniformly over the globe. As the GPS signals pass through the atmosphere, they are refracted due to the refractivity gradients along the path. The receivers on board of COSMIC satellites measure the phase and amplitudes of GPS radio signals. From these measurements, we can derive profiles of bending angles and refractivity. The derived GPS radio occultation soundings from COSMIC will be used by major operational meteorological centers including NOAA's National Centers for Environmental Prediction (NCEP) and the European Centre for Medium Range Forecasts (ECMWF). The COSMIC constellation is currently scheduled to be launched in late 2005, and is expected to last for five years. In addition to the GPS payload, COSMIC will have an ionospheric photometer and a tri-band beacon. Data will be made freely available to the international scientific community in near real time.

Ector, D.; Kuo, B.; Rocken, C.

465

A summary of the GPS system performance for STARS Mission 3  

SciTech Connect

This paper describes the performance of the GPS system on the most recent flight of the STARS missile, STARS Mission 3 (M3). This mission was conducted under the Ballistic Missile Defense Organization`s (BMDO`s) Consolidated Targets Program. The United States Army Space and Strategic Defense Command (USASSDC) is the executing agent for this mission and the Department of Energy`s (DOE`s) Sandia National Laboratories (SNL) is the vehicle developer and integrator. The M3 flight, dually designated as the MSX Dedicated Targets II (MDT-II) mission occurred on August 31, 1996. This mission was conducted for the specific purpose of providing targets for viewing by the MSX satellite. STARS M3 was the first STARS flight to use GPS-derived data for missile guidance, and proved to be instrumental in the procurement of a wealth of experimental data which is still undergoing analysis by numerous scientific agencies within the BMDO complex. GPS accuracy was required for this mission because of the prescribed targeting requirements for the MDT-II payload deliveries with respect to the MSX satellite flight path. During the flight test real time GPS-derived state vector data was also used to generate pointing angles for various down range sensors involved in the experiment. Background information describing the STARS missile, GPS subsystem architecture, and the GPS Kalman filter design is presented first, followed by a discussion of the telemetry data records obtained from this flight with interpretations and conclusions.

Creel, E.E.

1997-08-01

466

Solid waste monitoring system integration based on RFID, GPS and camera  

Microsoft Academic Search

The integration of communication technologies such as radio frequency identification (RFID), global positioning system (GPS), general packet radio system (GPRS), geographic information system (GIS) with a camera are constructed for solid waste monitoring system. The aim is to improve the way of responding to customer's inquiry and emergency cases and estimate the solid waste amount without any involvement of the

Maher Arebey; M. A. Hannan; Hassan Basri; R. A. Begum; Huda Abdullah

2010-01-01

467

Vision-aided inertial navigation system for robotic mobile mapping  

NASA Astrophysics Data System (ADS)

A mapping system by vision-aided inertial navigation was developed for areas where GNSS signals are unreachable. In this framework, a methodology on the integration of vision and inertial sensors is presented, analysed and tested. The system employs the method of “SLAM: Simultaneous Localisation And Mapping” where the only external input available to the system at the beginning of the mapping mission is a number of features with known coordinates. SLAM is a term used in the robotics community to describe the problem of mapping the environment and at the same time using this map to determine the location of the mapping device. Differing from the robotics approach, the presented development stems from the frameworks of photogrammetry and kinematic geodesy that are merged in two filters that run in parallel: the Least-Squares Adjustment (LSA) for features coordinates determination and the Kalman filter (KF) for navigation correction. To test this approach, a mapping system-prototype comprising two CCD cameras and one Inertial Measurement Unit (IMU) is introduced. Conceptually, the outputs of the LSA photogrammetric resection are used as the external measurements for the KF that corrects the inertial navigation. The filtered position and orientation are subsequently employed in the photogrammetric intersection to map the surrounding features that are used as control points for the resection in the next epoch. We confirm empirically the dependency of navigation performance on the quality of the images and the number of tracked features, as well as on the geometry of the stereo-pair. Due to its autonomous nature, the SLAM's performance is further affected by the quality of IMU initialisation and the a-priory assumptions on error distribution. Using the example of the presented system we show that centimetre accuracy can be achieved in both navigation and mapping when the image geometry is optimal.

Bayoud, Fadi; Skaloud, Jan

2008-04-01

468

Supporting EarthScope Cyber-Infrastructure with a Modern GPS Science Data System  

NASA Astrophysics Data System (ADS)

Building on NASA's investment in the measurement of crustal deformation from continuous GPS, we are developing and implementing a Science Data System (SDS) that will provide mature, long-term Earth Science Data Records (ESDR's). This effort supports NASA's Earth Surface and Interiors (ESI) focus area and provide NASA's component to the EarthScope PBO. This multi-year development is sponsored by NASA's Making Earth System data records for Use in Research Environments (MEaSUREs) program. The SDS integrates the generation of ESDRs with data analysis and exploration, product generation, and modeling tools based on daily GPS data that include GPS networks in western North America and a component of NASA's Global GPS Network (GGN) for terrestrial reference frame definition. The system is expandable to multiple regional and global networks. The SDS builds upon mature data production, exploration, and analysis algorithms developed under NASA's REASoN, ACCESS, and SENH programs. This SDS provides access to positions, time series, velocity fields, and strain measurements derived from continuous GPS data obtained at tracking stations in both the Plate Boundary Observatory and other regional Western North America GPS networks, dating back to 1995. The SDS leverages the IT and Web Services developments carried out under the SCIGN/REASoN and ACCESS projects, which have streamlined access to data products for researchers and modelers, and which have created a prototype an on-the-fly interactive research environment through a modern data portal, GPS Explorer. This IT system has been designed using modern IT tools and principles in order to be extensible to any geographic location, scale, natural hazard, and combination of geophysical sensor and related data. We have built upon open GIS standards, particularly those of the OGC, and have used the principles of Web Service-based Service Oriented Architectures to provide scalability and extensibility to new services and capabilities.

Webb, F. H.; Bock, Y.; Kedar, S.; Jamason, P.; Fang, P.; Dong, D.; Owen, S. E.; Prawirodirjo, L.; Squibb, M.

2008-12-01

469

Relationships between GPS-signal propagation errors and EISCAT observations  

Microsoft Academic Search

When travelling through the ionosphere the signals of space-based radio navigation systems such as the Global Positioning System (GPS) are subject to modifica- tions in amplitude, phase and polarization. In particular, phase changes due to refraction lead to propagation er- rors of up to 50 m for single-frequency GPS users. If both the L1 and the L2 frequencies transmitted by

N. Jakowski; E. Sardon; E. Engler; A. Jungstand; D. Klähn

1996-01-01

470

Briefing highlights space weather risks to GPS  

NASA Astrophysics Data System (ADS)

Solar storms, which are expected to increase as the Sun nears the most active phase of the solar cycle, can disrupt a variety of technologies on which society relies. Speakers at a 22 June briefing on Capitol Hill in Washington, D. C., focused on how space weather can affect the Global Positioning System (GPS), which is used in a wide range of industries, including commercial air travel, agriculture, national security, and emergency response. Rocky Stone, chief technical pilot for United Airlines, noted that