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1

Inertial navigation and GPS  

Microsoft Academic Search

The theory, history, mechanization, and error propagation characteristics of inertial navigators are briefly reviewed, and the specific benefits of integrating an inertial navigation system (INS) with GPS are addressed. INS benefits to GPS include an increased navigation accuracy of a mission under hostile jamming conditions, GPS-INS velocity instrument accuracies of about 3 cm\\/sec per axis under dynamic conditions, integrity monitoring

Marvin B. May

1993-01-01

2

A GPS\\/inertial navigation system design evaluator  

Microsoft Academic Search

A GPS\\/inertial navigation system evaluator simulation tool (i.e., the ENSIM-RSIM program) is described, and results from its application to a recent GPS\\/inertial system concept evaluation effort are presented. The effort was directed at the development of data processing techniques for effective use of GPS measurements in the navigation system Kalman filter. The closed-loop evaluator simulation modeled the dynamic interactions of

M. A. Vogel; T. J. MacDonald; J. L. Covert

1981-01-01

3

GPS based attitude determining system for marine navigation  

Microsoft Academic Search

Under contract with the US Coast Guard, Adroit Systems, Inc. has developed a low cost, GPS based attitude determining system (ADS) for marine navigation, TRIADS. The Coast Guard will use the system for general navigation, as well as hydrographic surveying, ice breaker navigation, and positioning buoys or other objects. Following a successful system demonstration validating the concept design, a system

Debra Diefes

1994-01-01

4

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 (GPS) AGENCY: Federal Aviation...Navigation Equipment Using the Global Positioning System (GPS), and request for public...Navigation Equipment Using the Global Positioning System (GPS). The effect of the...

2011-08-16

5

76 FR 66750 - Certain Automotive GPS Navigation Systems, Components Thereof, and Products Containing Same...  

Federal Register 2010, 2011, 2012, 2013

...COMMISSION [DN 2850] Certain Automotive GPS Navigation Systems, Components...complaint entitled In Re Certain Automotive GPS Navigation Systems, Components...after importation of certain automotive gps navigation systems, components...Identify any public health, safety, or welfare concerns in...

2011-10-27

6

Inertial navigation and GPS  

NASA Astrophysics Data System (ADS)

The theory, history, mechanization, and error propagation characteristics of inertial navigators are briefly reviewed, and the specific benefits of integrating an inertial navigation system (INS) with GPS are addressed. INS benefits to GPS include an increased navigation accuracy of a mission under hostile jamming conditions, GPS-INS velocity instrument accuracies of about 3 cm/sec per axis under dynamic conditions, integrity monitoring based on receiver autonomous integrity monitoring, and precise positioning.

May, Marvin B.

1993-09-01

7

The development of an integrated GPS\\/INS\\/sonar navigation system for autonomous underwater vehicle navigation  

Microsoft Academic Search

The need to successfully navigate in an underwater environment is rapidly becoming an important concern in the 1990's. This paper presents the development of an integrated navigation system for autonomous underwater vehicles (AUV) using GPS, INS and sonar. This paper discusses the existing problems with sub-sea navigation, the motivation for an integrated system, the mathematical derivation for an integrated GPS\\/INS\\/sonar

M. Bennamoun; B. Boashash; F. Faruqi; M. Dunbar

1996-01-01

8

Data fusion of ALV GPS\\/DR integrated navigation system based on BP neural network  

Microsoft Academic Search

Integrated navigation system of ALV is discussed in this paper, a data fusion method based on BP (back propagation) neural network is proposed for ALV's GPS\\/DR integrated navigation. System models have been established based on this data fusion method. Integrated navigation system uses GPS parameters as criterion to judge the validity of GPS. When GPS is valid, neural network is

Meiling Wang; Yongwei Fu

2009-01-01

9

INS\\/GPS navigation systems for land applications  

Microsoft Academic Search

Kearfott has developed a family of ring laser gyroscope (RLG) angular displacement and linear acceleration sensors which have been integrated with GPS in various configurations to address the operational requirements and cost of ownership constraints for tactical applications. This paper discusses the considerations in developing a military land navigation system which meets the rigid performance criteria and makes uses of

R. Tranfield

1996-01-01

10

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

11

Flight evaluation of differential GPS aided inertial navigation systems  

NASA Technical Reports Server (NTRS)

Algorithms are described for integration of Differential Global Positioning System (DGPS) data with Inertial Navigation System (INS) data to provide an integrated DGPS/INS navigation system. The objective is to establish the benefits that can be achieved through various levels of integration of DGPS with INS for precision navigation. An eight state Kalman filter integration was implemented in real-time on a twin turbo-prop transport aircraft to evaluate system performance during terminal approach and landing operations. A fully integrated DGPS/INS system is also presented which models accelerometer and rate-gyro measurement errors plus position, velocity, and attitude errors. The fully integrated system was implemented off-line using range-domain (seventeen-state) and position domain (fifteen-state) Kalman filters. Both filter integration approaches were evaluated using data collected during the flight test. Flight-test data consisted of measurements from a 5 channel Precision Code GPS receiver, a strap-down Inertial Navigation Unit (INU), and GPS satellite differential range corrections from a ground reference station. The aircraft was laser tracked to determine its true position. Results indicate that there is no significant improvement in positioning accuracy with the higher levels of DGPS/INS integration. All three systems provided high-frequency (e.g., 20 Hz) estimates of position and velocity. The fully integrated system provided estimates of inertial sensor errors which may be used to improve INS navigation accuracy should GPS become unavailable, and improved estimates of acceleration, attitude, and body rates which can be used for guidance and control. Precision Code DGPS/INS positioning accuracy (root-mean-square) was 1.0 m cross-track and 3.0 m vertical. (This AGARDograph was sponsored by the Guidance and Control Panel.)

Mcnally, B. David; Paielli, Russell A.; Bach, Ralph E., Jr.; Warner, David N., Jr.

1992-01-01

12

OEM4 Inertial: A Tightly Integrated Decentralised Inertial\\/GPS Navigation System  

Microsoft Academic Search

The synergy between GPS and inertial navigation has been well known in the industry since the inception of GPS. In theory, the continuity of the inertial system can both fill in positioning gaps left by GPS satellite outages and reduce the effect of high frequency GPS errors, while the unbiased nature of the GPS signals can limit the size of

Tom Ford; Janet Neumann; Pat Fenton; Mike Bobye; Jason Hamilton

13

Evaluation of Mobile Phone Interference With Aircraft GPS Navigation Systems  

NASA Technical Reports Server (NTRS)

This report compiles and analyzes tests that were conducted to measure cell phone spurious emissions in the Global Positioning System (GPS) radio frequency band that could affect the navigation system of an aircraft. The cell phone in question had, as reported to the FAA (Federal Aviation Administration), caused interference to several GPS receivers on-board a small single engine aircraft despite being compliant with data filed at the time with the FCC by the manufacturer. NASA (National Aeronautics and Space Administration) and industry tests show that while there is an emission in the 1575 MHz GPS band due to a specific combination of amplifier output impedance and load impedance that induces instability in the power amplifier, these spurious emissions (i.e., not the intentional transmit signal) are similar to those measured on non-intentionally transmitting devices such as, for example, laptop computers. Additional testing on a wide sample of different commercial cell phones did not result in any emission in the 1575 MHz GPS Band above the noise floor of the measurement receiver.

Pace, Scott; Oria, A. J.; Guckian, Paul; Nguyen, Truong X.

2004-01-01

14

Assisted GPS and its impact on navigation in intelligent transportation systems  

Microsoft Academic Search

The purpose of this paper is to discuss the assisted GPS positioning technique and its impact on the navigation in intelligent transportation systems. Due to the FCC E911 mandate and the market requirements for location based services, the mobile wireless communications and GPS positioning have been forced to merge. The assisted GPS, which integrates the mobile phone with GPS receiver,

Shaojun Feng; Choi Look Law

2002-01-01

15

A Personal Navigation System Using Low-Cost MEMS\\/GPS\\/Fluxgate  

Microsoft Academic Search

The advances of MEMS technology have led the development of small-sized sensors (inertial sensors, magnetic compass sensors, etc.). Small-sized GPS receivers also have been developed using only one GPS chipset. For the synergistic effect, the integrated system of these systems has been adopted in many navigation systems. In this paper, a new algorithm for pedestrian navigation systems (PNS) using the

Seong Yun Cho; Chan Gook

2003-01-01

16

78 FR 68861 - Certain Navigation Products, Including GPS Devices, Navigation and Display Systems, Radar Systems...  

Federal Register 2010, 2011, 2012, 2013

...Radar Systems, Navigational Aids, Mapping Systems and Related Software; Institution...radar systems, navigational aids, mapping systems and related software by reason...radar systems, navigational aids, mapping systems and related software by...

2013-11-15

17

Remote Control System for Projectile of Infrared Imaging Fuze Based on GPS and Navigation Technology  

Microsoft Academic Search

This article introduces remote control system for motion of projectile of infrared imaging fuze based on GPS and navigation technology, which is composed of GPS receiver, navigation sensor part, DSP data processor, wireless communication part, motion visual part and other parts. Observer on earth could inspect real time track of projectile compared with theoretical data at a special point of

Lin Li; He Zhang

2006-01-01

18

Improved particle filter algorithm for INS\\/GPS integrated navigation system  

Microsoft Academic Search

hotmail.com Abstract - The INS\\/GPS navigation system is obvious nonlinear under the large initial condition errors.To tackle the accuracy of integrated navigation under nonlinear model, a improved particle filter named cubature particle filter (CPF) is applied to INS\\/GPS integrated navigation. For this, the nonlinear state model based on the platform misalignment angle and the observation model described by the velocity

Feng Sun; Lijun Tang

2011-01-01

19

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

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

20

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

21

Comparison of ionospheric total electron content from the Navy Navigation Satellite System and the GPS  

Microsoft Academic Search

About 25,000 total electron content (TEC) values obtained in 2 years from Navy Navigation Satellite System (NNSS) differential Doppler were compared with the corresponding TECs obtained from the Global Positioning System (GPS). The method by which the comparison is effected is also described. The resulting statistics are very effective in showing a good agreement between the two techniques. The GPS

Luigi Ciraolo; Paolo Spalla

1997-01-01

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...

2002-01-01

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...

2005-01-01

24

Observability and performance analysis of integrated GPS\\/INS navigation systems  

Microsoft Academic Search

This primary objective of this thesis is to analyze the performance and observability characteristics of integrated navigation systems which fuse the information from the Global Positioning System (GPS) and Inertial Navigation Systems (INS) of varying quality. It is shown that INS output error characteristics affect the notion of observability with these systems. More specifically; it is shown that when INS

Yunfeng Shao

2006-01-01

25

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

2012-01-01

26

FPGA-Based Real-Time Embedded System for RISS/GPS Integrated Navigation  

PubMed Central

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.

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

2012-01-01

27

Error Analysis System for Spacecraft Navigation Using the Global Positioning System (GPS)  

NASA Technical Reports Server (NTRS)

The Flight Dynamics Division (FDD) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) is currently developing improved space-navigation filtering algorithms to use the Global Positioning System (GPS) for autonomous real-time onboard orbit determination. In connection with a GPS technology demonstration on the Small Satellite Technology Initiative (SSTI)/Lewis spacecraft, FDD analysts and programmers have teamed with the GSFC Guidance, Navigation, and Control Branch to develop the GPS Enhanced Orbit Determination Experiment (GEODE) system. The GEODE system consists of a Kalman filter operating as a navigation tool for estimating the position, velocity, and additional states required to accurately navigate the orbiting Lewis spacecraft by using astrodynamic modeling and GPS measurements from the receiver. A parallel effort at the FDD is the development of a GPS Error Analysis System (GEAS) that will be used to analyze and improve navigation filtering algorithms during development phases and during in-flight calibration. For GEAS, the Kalman filter theory is extended to estimate the errors in position, velocity, and other error states of interest. The estimation of errors in physical variables at regular intervals will allow the time, cause, and effect of navigation system weaknesses to be identified. In addition, by modeling a sufficient set of navigation system errors, a system failure that causes an observed error anomaly can be traced and accounted for. The GEAS software is formulated using Object Oriented Design (OOD) techniques implemented in the C++ programming language on a Sun SPARC workstation. The Phase 1 of this effort is the development of a basic system to be used to evaluate navigation algorithms implemented in the GEODE system. This paper presents the GEAS mathematical methodology, systems and operations concepts, and software design and implementation. Results from the use of the basic system to evaluate navigation algorithms implemented on GEODE are also discussed. In addition, recommendations for generalization of GEAS functions and for new techniques to optimize the accuracy and control of the GPS autonomous onboard navigation are presented.

Truong, S. H.; Hart, R. C.; Hartman, K. R.; Tomcsik, T. L.; Searl, J. E.; Bernstein, A.

1997-01-01

28

Time Synchronization Errors in Loosely Coupled GPS-Aided Inertial Navigation Systems  

Microsoft Academic Search

The effects of data time synchronization errors in a loosely coupled Global-Positioning-System (GPS)-aided inertial navigation system (INS) are studied and quantified in terms of the increased mean square error (MSE) of the navigation solution. An expression for evaluating the MSE of the navigation solution, given the vehicle trajectory and the model of the INS error dynam- ics, is derived. Thereafter,

Isaac Skog; Peter Handel

2011-01-01

29

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

NASA Technical Reports Server (NTRS)

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

Truong, Son H.

1999-01-01

30

A LOW-COST GPS AIDED INERTIAL NAVIGATION SYSTEM FOR VEHICLE APPLICATIONS  

Microsoft Academic Search

In this paper an approach for integration between GPS and inertial navigation systems (INS) is described. The continuous-time nav- igation and error equations for an earth-centered earth-fixed INS system are presented. Using zero order hold sampling, the set of equations is discretized. An extended Kalman filter for closed loop integration between the GPS and INS is derived. The filter propa-

Isaac Skog; Peter H

31

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

NASA Technical Reports Server (NTRS)

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

Truong, S. H.

1999-01-01

32

Observability and performance analysis of integrated GPS/INS navigation systems  

NASA Astrophysics Data System (ADS)

This primary objective of this thesis is to analyze the performance and observability characteristics of integrated navigation systems which fuse the information from the Global Positioning System (GPS) and Inertial Navigation Systems (INS) of varying quality. It is shown that INS output error characteristics affect the notion of observability with these systems. More specifically; it is shown that when INS sensor quality is low, the traditional metrics of deterministic and stochastic observability are incomplete metrics to describe the system performance. Accordingly, a new metric as well as detailed trade study results that characterize the observability of GPS/INS fusion filter which use low quality inertial sensors is developed. A secondary objective of this thesis is to evaluate the use of an integrated GPS/INS system in two aviation applications of significant current interest. The first application is about monitoring and mitigating the impact of structural flexure of an aircraft carrier which is he host of the GPS-based landing system known as Joint Precision Approach and Landing Systems (JPALS). A mathematic error model is developed and validated using experimental ship motion data. The second application is that of checking the integrity of the GPS signal used in GPS-based landing systems such as JPALS and other landing systems envisioned for future use in commercial aviation. An inertial aided Receiver Autonomous Integrity Monitoring (RAIM) algorithm is designed and its performance improvements with inertial aiding are quantified.

Shao, Yunfeng

33

Inertial Navigation System Aided by GPS and Selective Frequency Contents of Vector Measurements  

Microsoft Academic Search

This paper proposes an aiding technique to enhance error estimation in low-cost strap- down inertial navigation systems with application to Unmanned Air Vehicles (UAVs). The paper summarizes a high-accuracy, multi-rate integrated Global Positioning System\\/Inerti- al Navigation System (GPS\\/INS) using Extended Kalman Filter (EKF) for error compen- sation. A proposed new technique decomposes and optimally integrates the magnetic and gravitational observations

J. F. Vasconcelos

34

Orbit Determination Using GPS Navigation Solution  

Microsoft Academic Search

The Global Positioning System (GPS) is a satellite navigation system that allows the users to determine position, velocity and the time with high precision. Its main purposes are aid to radionavigation in three dimensions with high precision positioning, navigation in real time, global coverage and quick acquisition of data sent by the GPS satellites. The purpose of this work is

V. M. Gomes; H. K. Kuga; A. P. Chiaradia; A. F. Prado

2004-01-01

35

Vehicle Path-Following with a GPS-aided Inertial Navigation System  

Microsoft Academic Search

This article describes a methodology to guide a passenger car along a predefined path in order to perform drive tests. A feedback\\/feedforward control scheme for this path-following problem is described. The controller is based on measurements which are provided by a GPS aided navigation system. Thereby, problems arise in course of the implementation of such a high-precision navigation system due

Steffen Kehl; Wolf-Dieter Pölsler; Michael Zeitz

36

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

37

Adaptive Resampling Particle Filters for GPS Carrier-Phase Navigation and Collision Avoidance System  

NASA Astrophysics Data System (ADS)

This dissertation addresses three problems: 1) adaptive resampling technique (ART) for Particle Filters, 2) precise relative positioning using Global Positioning System (GPS) Carrier-Phase (CP) measurements applied to nonlinear integer resolution problem for GPS CP navigation using Particle Filters, and 3) collision detection system based on GPS CP broadcasts. First, Monte Carlo filters, called Particle Filters (PF), are widely used where the system is non-linear and non-Gaussian. In real-time applications, their estimation accuracies and efficiencies are significantly affected by the number of particles and the scheduling of relocating weights and samples, the so-called resampling step. In this dissertation, the appropriate number of particles is estimated adaptively such that the error of the sample mean and variance stay in bounds. These bounds are given by the confidence interval of a normal probability distribution for a multi-variate state. Two required number of samples maintaining the mean and variance error within the bounds are derived. The time of resampling is determined when the required sample number for the variance error crosses the required sample number for the mean error. Second, the PF using GPS CP measurements with adaptive resampling is applied to precise relative navigation between two GPS antennas. In order to make use of CP measurements for navigation, the unknown number of cycles between GPS antennas, the so called integer ambiguity, should be resolved. The PF is applied to this integer ambiguity resolution problem where the relative navigation states estimation involves nonlinear observations and nonlinear dynamics equation. Using the PF, the probability density function of the states is estimated by sampling from the position and velocity space and the integer ambiguities are resolved without using the usual hypothesis tests to search for the integer ambiguity. The ART manages the number of position samples and the frequency of the resampling step for real-time kinematics GPS navigation. The experimental results demonstrate the performance of the ART and the insensitivity of the proposed approach to GPS CP cycle-slips. Third, the GPS has great potential for the development of new collision avoidance systems and is being considered for the next generation Traffic alert and Collision Avoidance System (TCAS). The current TCAS equipment, is capable of broadcasting GPS code information to nearby airplanes, and also, the collision avoidance system using the navigation information based on GPS code has been studied by researchers. In this dissertation, the aircraft collision detection system using GPS CP information is addressed. The PF with position samples is employed for the CP based relative position estimation problem and the same algorithm can be used to determine the vehicle attitude if multiple GPS antennas are used. For a reliable and enhanced collision avoidance system, three dimensional trajectories are projected using the estimates of the relative position, velocity, and the attitude. It is shown that the performance of GPS CP based collision detecting algorithm meets the accuracy requirements for a precise approach of flight for auto landing with significantly less unnecessary collision false alarms and no miss alarms.

Hwang, Soon Sik

38

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

39

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

40

Space Shuttle Navigation in the GPS Era  

NASA Technical Reports Server (NTRS)

The Space Shuttle navigation architecture was originally designed in the 1970s. A variety of on-board and ground based navigation sensors and computers are used during the ascent, orbit coast, rendezvous, (including proximity operations and docking) and entry flight phases. With the advent of GPS navigation and tightly coupled GPS/INS Units employing strapdown sensors, opportunities to improve and streamline the Shuttle navigation process are being pursued. These improvements can potentially result in increased safety, reliability, and cost savings in maintenance through the replacement of older technologies and elimination of ground support systems (such as Tactical Air Control and Navigation (TACAN), Microwave Landing System (MLS) and ground radar). Selection and missionization of "off the shelf" GPS and GPS/INS units pose a unique challenge since the units in question were not originally designed for the Space Shuttle application. Various options for integrating GPS and GPS/INS units with the existing orbiter avionics system were considered in light of budget constraints, software quality concerns, and schedule limitations. An overview of Shuttle navigation methodology from 1981 to the present is given, along with how GPS and GPS/INS technology will change, or not change, the way Space Shuttle navigation is performed in the 21 5 century.

Goodman, John L.

2001-01-01

41

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

42

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

Microsoft Academic Search

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

Masaru Naruoka; Takeshi Tsuchiya

2008-01-01

43

Indoor Navigation Test Results using an Integrated GPS/TOA/Inertial Navigation System.  

National Technical Information Service (NTIS)

NAVSYS has developed a networked radionavigation approach for operating in urban environments where GPS signals can be significantly attenuated or completely blocked. The networked radionavigation approach is based on a Software Defined Radio (SDR) testbe...

A. Brown Y. Lu

2006-01-01

44

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

45

A System-On-Chip (SOC) platform to integrated Inertial Navigation Systems & GPS  

Microsoft Academic Search

Currently there are quite works investigate the inertial measurement unit (IMU) and the Global Position System (GPS) fusion. The majority are implemented on personal computers, due to the high computational cost. However, nowadays there are system on chip (SOC) platforms with a lot of resources capable of the integration with GPS\\/IMS, providing a high performance, variety of peripherals, ease communication

Alex Garcia-Quinchia; Yi Guo; E. Martin; C. Ferrer

2009-01-01

46

USING LOW-COST MEMS 3D ACCELEROMETER AND ONE GYRO TO ASSIST GPS BASED CAR NAVIGATION SYSTEM  

Microsoft Academic Search

This paper presents the development of GPS based navigation system for portable devices at Tampere University of Technology. The objective was to develop a fully integrated system using MEMS inertial sensors with price range of US$ 10-15 for the set of inertial sensors combined with low-update rate GPS measurements. This system doesn't require vehicle installation and can be easily transferred

Pavel Davidson; Jani Hautamäki; Jussi Collin

47

A step toward GPS\\/INS personal navigation systems: real-time assessment of gait by foot inertial sensing  

Microsoft Academic Search

In this paper, we develop a system for which applications in the field of personal navigation are planned. In the current version, the system embodies a Global Positioning System (GPS) receiver and an inertial measurement unit (IMU), composed of two dual-axis accelerometers and one single-axis gyro. The IMU is positioned at a subject's foot instep, and it is intended to

Filippo Cavallo; Angelo M. Sabatini; Vincenzo Genovese

2005-01-01

48

Design and flight test of a differential GPS/inertial navigation system for approach/landing guidance  

NASA Technical Reports Server (NTRS)

NASA-Langley has conducted a flight test program evaluating a differential GPS/inertial navigation system's (DGPS/INS) utility as an approach/landing aid. The DGPS/INS airborne and ground components are based on off-the-shelf transport aircraft avionics, namely a global positioning/inertial reference unit (GPIRU) and two GPS sensor units (GPSSUs). Systematic GPS errors are measured by the ground GPSSU and transmitted to the aircraft GPIRU, allowing the errors to be eliminated or greatly reduced in the airborne equipment. Over 120 landings were flown; 36 of these were fully automatic DGPS/INS landings.

Vallot, Lawrence; Snyder, Scott; Schipper, Brian; Parker, Nigel; Spitzer, Cary

1991-01-01

49

Definition study of land/sea civil user navigational location monitoring systems for NAVSTAR GPS: User requirements and systems concepts  

NASA Technical Reports Server (NTRS)

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 this capability and the civil user navigation and location-monitoring requirements. Existing survey literature was examined to ascertain the potential users of a low-cost NAVSTAR receiver and to estimate their number, function, and accuracy requirements. System concepts are defined for low cost user equipments for in-situ navigation and the retransmission of low data rate positioning data via a geostationary satellite to a central computing facility.

Devito, D. M.

1981-01-01

50

Dual RF Astrodynamic GPS Orbital Navigator Satellite  

NASA Technical Reports Server (NTRS)

Dual RF Astrodynamic GPS Orbital Navigator Satellite (DRAGONSat) will demonstrate autonomous rendezvous and docking (ARD) in low Earth orbit (LEO) and gather flight data with a global positioning system (GPS) receiver strictly designed for space applications. ARD is the capability of two independent spacecraft to rendezvous in orbit and dock without crew intervention. DRAGONSat consists of two picosatellites (one built by the University of Texas and one built by Texas A and M University) and the Space Shuttle Payload Launcher (SSPL); this project will ultimately demonstrate ARD in LEO.

Kanipe, David B.; Provence, Robert Steve; Straube, Timothy M.; Reed, Helen; Bishop, Robert; Lightsey, Glenn

2009-01-01

51

Integrity Performance Models for a Combined Galileo\\/GPS Navigation System  

Microsoft Academic Search

Integrity relates to the trust that can be placed in the correctness of information supplied by a navigation system. It includes the ability of the navigation system to provide timely warnings to users when the system fails to meet its stated accuracy. Specifically, a navigation system is required to deliver a warning (alarm) when the error in the derived user

W. Y. OCHIENG; K. F. SHERIDAN; X. HAN; P. A. CROSS; S. LANNELONGUE

52

Position, Navigation, and Timing: GPS Scientific Applications  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the development and deployment of the Global Positioning System (GPS). This presentation also includes measuring space and time, GPS as a tool for science, development of high precision JPL GPS receivers, and technology and applications developments.

Neilan, Ruth E.

2008-01-01

53

Autonomous Navigation Improvements for High-Earth Orbiters Using GPS  

NASA Technical Reports Server (NTRS)

The Goddard Space Flight Center is currently developing autonomous navigation systems for satellites in high-Earth orbits where acquisition of the GPS signals is severely limited This paper discusses autonomous navigation improvements for high-Earth orbiters and assesses projected navigation performance for these satellites using Global Positioning System (GPS) Standard Positioning Service (SPS) measurements. Navigation performance is evaluated as a function of signal acquisition threshold, measurement errors, and dynamic modeling errors using realistic GPS signal strength and user antenna models. These analyses indicate that an autonomous navigation position accuracy of better than 30 meters root-mean-square (RMS) can be achieved for high-Earth orbiting satellites using a GPS receiver with a very stable oscillator. This accuracy improves to better than 15 meters RMS if the GPS receiver's signal acquisition threshold can be reduced by 5 dB-Hertz to track weaker signals.

Long, Anne; Kelbel, David; Lee, Taesul; Garrison, James; Carpenter, J. Russell; Bauer, F. (Technical Monitor)

2000-01-01

54

Autonomous Relative Navigation for Formation-Flying Satellites Using GPS  

NASA Technical Reports Server (NTRS)

The Goddard Space Flight Center is currently developing advanced spacecraft systems to provide autonomous navigation and control of formation flyers. This paper discusses autonomous relative navigation performance for a formation of four eccentric, medium-altitude Earth-orbiting satellites using Global Positioning System (GPS) Standard Positioning Service (SPS) and "GPS-like " intersatellite measurements. The performance of several candidate relative navigation approaches is evaluated. These analyses indicate that an autonomous relative navigation position accuracy of 1meter root-mean-square can be achieved by differencing high-accuracy filtered solutions if only measurements from common GPS space vehicles are used in the independently estimated solutions.

Gramling, Cheryl; Carpenter, J. Russell; Long, Anne; Kelbel, David; Lee, Taesul

2000-01-01

55

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

56

Shuttle Global Positioning System (GPS) design study  

NASA Technical Reports Server (NTRS)

The effects of oscillator noise on Shuttle Global Positioning System (GPS) receiver performance, GPS navigation system self-test, GPS ground transmitter design to augment shuttle navigation, the effect of ionospheric delay modelling on GPS receiver design, and GPS receiver tracking of Shuttle transient maneuvers were investigated.

Nilsen, P. W.

1979-01-01

57

NAVIGATION PERFORMANCE IN HIGH EARTH ORBITS USING NAVIGATOR GPS RECEIVER  

NASA Technical Reports Server (NTRS)

NASA GSFC has developed a GPS receiver that can acquire and track GPS signals with sensitivity significantly lower than conventional GPS receivers. This opens up the possibility of using GPS based navigation for missions in high altitude orbit, such as Geostationary Operational Environmental Satellites (GOES) in a geostationary orbit, and the Magnetospheric MultiScale (MMS) Mission, in highly eccentric orbits extending to 12 Earth radii and higher. Indeed much research has been performed to study the feasibility of using GPS navigation in high Earth orbits and the performance achievable. Recently, GSFC has conducted a series of hardware in-the-loop tests to assess the performance of this new GPS receiver in various high Earth orbits of interest. Tracking GPS signals to down to approximately 22-25 dB-Hz, including signals from the GPS transmitter side-lobes, steady-state navigation performance in a geostationary orbit is on the order of 10 meters. This paper presents the results of these tests, as well as sensitivity analysis to such factors as ionosphere masks, use of GPS side-lobe signals, and GPS receiver sensitivity.

Bamford, William; Naasz, Bo; Moreau, Michael C.

2006-01-01

58

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

59

Using goGPS software with a multi-antenna GPS system to improve navigation with low-cost receivers  

NASA Astrophysics Data System (ADS)

goGPS is a free and open source software package designed to enhance the accuracy of single frequency low-cost GPS devices by employing an extended Kalman filter. This filter can be applied either in post-processing or in real-time and it is specifically tailored for addressing the issues related to low-cost GPS receivers. To further enhance the accuracy of kinematic positioning and to jointly estimate the rover velocity and attitude, in the present work a multi-antenna approach has been investigated and integrated into the goGPS Kalman filter. In this approach the known and fixed geometry of a cluster of low-cost antennas is used to constrain the solution. The improvements obtained by the proposed technique are evaluated with the use of three u-blox LEA-4T receivers in a test scenario.

Caldera, Stefano; Gatti, Andrea; Pertusini, Lisa; Realini, Eugenio; Reguzzoni, Mirko; Sampietro, Daniele

2013-04-01

60

Singular Value Decomposition-Based Robust Cubature Kalman Filter for AN Integrated Gps/sins Navigation System  

NASA Astrophysics Data System (ADS)

A new nonlinear robust filter is proposed in this paper to deal with the outliers of an integrated GPS/SINS navigation system. The influence of different design parameters for H? cubature Kalman filter is analysed. It is found that when the design parameter is smaller, the robustness of the filter is stronger. However, the design parameter is easily out of step with the Riccati equation and the filter is easy to diverge. In this respect, the singular value decomposition algorithm is employed to replace Cholesky decomposition in the robust cubature Kalman filter. On the wider conditions for design parameter, the new filter is more robust. The testing results demonstrate that the proposed filter algorithm is more reliable and effective in dealing the data sets produced by the integrated GPS/SINS system.

Zhang, Q.; Meng, X.; Zhang, S.; Wang, Y.

2014-03-01

61

Ionospheric specification algorithms for precise GPS-based aircraft navigation  

Microsoft Academic Search

The Federal Aviation Administration (FAA) is implementing an aircraft navigation scheme for the United States using the Global Positioning System (GPS) L1 signal (1575.42 MHz). To achieve position accuracies of a few meters, sufficient to allow precision airfield approaches, it will be necessary to broadcast corrections to the direct GPS signal. A significant component of these corrections is the delay

I. L. Harris; A. J. Mannucci; B. A. Iijima; U. J. Lindqwister; D. Muna; X. Pi; B. D. Wilson

2001-01-01

62

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

63

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle  

NASA Technical Reports Server (NTRS)

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.

1993-01-01

64

Non-GPS navigation with the personal dead-reckoning system  

NASA Astrophysics Data System (ADS)

This paper introduces a positioning system for walking persons, called "Personal Dead-reckoning" (PDR) system. The PDR system does not require GPS, beacons, or landmarks. The system is therefore useful in GPS-denied environments, such as inside buildings, tunnels, or dense forests. Potential users of the system are military and security personnel as well as emergency responders. The PDR system uses a small 6-DOF inertial measurement unit (IMU) attached to the user's boot. The IMU provides rate-of-rotation and acceleration measurements that are used in real-time to estimate the location of the user relative to a known starting point. In order to reduce the most significant errors of this IMU-based system-caused by the bias drift of the accelerometers-we implemented a technique known as "Zero Velocity Update" (ZUPT). With the ZUPT technique and related signal processing algorithms, typical errors of our system are about 2% of distance traveled. This typical PDR system error is largely independent of the gait or speed of the user. When walking continuously for several minutes, the error increases gradually beyond 2%. The PDR system works in both 2-dimensional (2-D) and 3-D environments, although errors in Z-direction are usually larger than 2% of distance traveled. Earlier versions of our system used an impractically large IMU. In the most recent version we implemented a much smaller IMU. This paper discussed specific problems of this small IMU, our measures for eliminating these problems, and our first experimental results with the small IMU under different conditions.

Ojeda, Lauro; Borenstein, Johann

2007-05-01

65

Operational Use of GPS Navigation for Space Shuttle Entry  

NASA Technical Reports Server (NTRS)

The STS-118 flight of the Space Shuttle Endeavour was the first shuttle mission flown with three Global Positioning System (GPS) receivers in place of the three legacy Tactical Air Navigation (TACAN) units. This marked the conclusion of a 15 year effort involving procurement, missionization, integration, and flight testing of a GPS receiver and a parallel effort to formulate and implement shuttle computer software changes to support GPS. The use of GPS data from a single receiver in parallel with TACAN during entry was successfully demonstrated by the orbiters Discovery and Atlantis during four shuttle missions in 2006 and 2007. This provided the confidence needed before flying the first all GPS, no TACAN flight with Endeavour. A significant number of lessons were learned concerning the integration of a software intensive navigation unit into a legacy avionics system. These lessons have been taken into consideration during vehicle design by other flight programs, including the vehicle that will replace the Space Shuttle, Orion.

Goodman, John L.; Propst, Carolyn A.

2008-01-01

66

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

67

Loosely Coupled GPS-Aided Inertial Navigation System for Range Safety  

NASA Technical Reports Server (NTRS)

The Autonomous Flight Safety System (AFSS) aims to replace the human element of range safety operations, as well as reduce reliance on expensive, downrange assets for launches of expendable launch vehicles (ELVs). The system consists of multiple navigation sensors and flight computers that provide a highly reliable platform. It is designed to ensure that single-event failures in a flight computer or sensor will not bring down the whole system. The flight computer uses a rules-based structure derived from range safety requirements to make decisions whether or not to destroy the rocket.

Heatwole, Scott; Lanzi, Raymond J.

2010-01-01

68

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

69

Ready To Navigate: Classroom GPS Applications.  

ERIC Educational Resources Information Center

Discusses the potential contribution of GPS and related Geographic Information Systems (GIS) technology to education. Provides resources for teachers to plan a lesson on exploring with the help of a GPS device in order to increase students' awareness of their surroundings and broaden understanding of their place in the world. (KHR)

Lucking, Robert A.; Christmann, Edwin P.

2002-01-01

70

Accuracy Assessment of a High Sensitivity GPS Based Pedestrian Navigation System Aided by Low-Cost Sensors1  

Microsoft Academic Search

This paper presents the results of the accuracy analysis of the sensor aided HSGPS receiver for pedestrian navigation in signal-degraded environments. Description of the downtown test and the equipment used is given. Analysis of the stand- alone HSGPS results with Receiver Autonomous Integrity Monitoring (RAIM) techniques is presented. Brief analysis of gyro bias estimation problems with GPS is presented. Kalman

O. Mezentsev; J. Collin; H. Kuusniemi; G. Lachapelle

71

The use of high sensitivity GPS for initialisation of a foot mounted inertial navigation system  

Microsoft Academic Search

This work aims to optimise the use of GNSS for intialising a foot mounted pedestrian INS. The INS error model used in many navigation filters requires the input of an accurate, precise initial position and heading for stable filter performance. However such information is often not available at the start of a navigation session. Often a rough initialisation is performed

James Pinchin; Chris Hide; Terry Moore

2012-01-01

72

GPS Auto-Navigation Design for Unmanned Air Vehicles  

NASA Technical Reports Server (NTRS)

A GPS auto-navigation system is designed for Unmanned Air Vehicles. The objective is to enable the air vehicle to be used as a test-bed for novel flow control concepts. The navigation system uses pre-programmed GPS waypoints. The actual GPS position, heading, and velocity are collected by the flight computer, a PC104 system running in Real-Time Linux, and compared with the desired waypoint. The navigator then determines the necessity of a heading correction and outputs the correction in the form of a commanded bank angle, for a level coordinated turn, to the controller system. This controller system consists of 5 controller! (pitch rate PID, yaw damper, bank angle PID, velocity hold, and altitude hold) designed for a closed loop non-linear aircraft model with linear aerodynamic coefficients. The ability and accuracy of using GPS data, is validated by a GPS flight. The autopilots are also validated in flight. The autopilot unit flight validations show that the designed autopilots function as designed. The aircraft model, generated on Matlab SIMULINK is also enhanced by the flight data to accurately represent the actual aircraft.

Nilsson, Caroline C. A.; Heinzen, Stearns N.; Hall, Charles E., Jr.; Chokani, Ndaona

2003-01-01

73

A GPS sonobuoy localization system  

Microsoft Academic Search

A GPS localization system is described that uses the precision navigation signal but does not require a SAASM decoding unit in the sonobuoy. The system operates by retransmitting a selected 1 MHz portion of the GPS L1 or L2 signal spectrum from the sonobuoy to a Master Control Station (MCS). By offsetting the selected spectrum about 2 MHz from the

Harper J. Whitehouse; J. M. Alsup; A. Leese de Escobar; Shelby F. Sullivan

2004-01-01

74

GPS-aided inertial technology and navigation-based photogrammetry for aerial mapping the San Andreas fault system  

USGS Publications Warehouse

Aerial mapping of the San Andreas Fault System can be realized more efficiently and rapidly without ground control and conventional aerotriangulation. This is achieved by the direct geopositioning of the exterior orientation of a digital imaging sensor by use of an integrated Global Positioning System (GPS) receiver and an Inertial Navigation System (INS). A crucial issue to this particular type of aerial mapping is the accuracy, scale, consistency, and speed achievable by such a system. To address these questions, an Applanix Digital Sensor System (DSS) was used to examine its potential for near real-time mapping. Large segments of vegetation along the San Andreas and Cucamonga faults near the foothills of the San Bernardino and San Gabriel Mountains were burned to the ground in the California wildfires of October-November 2003. A 175 km corridor through what once was a thickly vegetated and hidden fault surface was chosen for this study. Both faults pose a major hazard to the greater Los Angeles metropolitan area and a near real-time mapping system could provide information vital to a post-disaster response.

Sanchez, Richard D.; Hudnut, Kenneth W.

2004-01-01

75

Tightly-coupled GPS \\/ INS system design for autonomous urban navigation  

Microsoft Academic Search

This paper analyzes the design decisions made in building the tightly-coupled position, velocity, and attitude estimator used as a position feedback signal for autonomous navigation in Cornell University's 2007 DARPA urban challenge robot, 'Skynet.' A statistical sensitivity analysis is conducted on Skynet's estimator by examining the changes in its output as critical design decisions are reversed. The effects of five

Isaac Miller; Brian Schimpf; Mark Campbell; Jan Leyssens

2008-01-01

76

76 FR 72442 - Certain Automotive GPS Navigation Systems, Components Thereof, and Products Containing Same...  

Federal Register 2010, 2011, 2012, 2013

...U.S.C. 1337, on behalf of Beacon Navigation GmbH of Switzerland. A letter supplementing the complaint was filed on November...Treuhand AG, Innere G[uuml]terstrasse 4, 6304 Zug, Switzerland. (b) The respondents are the following entities...

2011-11-23

77

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

78

Sensitivity Analysis of a Tightly-Coupled GPS\\/INS System for Autonomous Navigation  

Microsoft Academic Search

The work presented here empirically analyzes the design of the tightly-coupled position, velocity, and attitude estimator used as a feedback signal for autonomous navigation in a large scale robot driving in urban settings. The estimator fuses GNSS\\/INS signals in an extended square root information filter (ESRIF), a numerically-robust implementation of an extended Kalman filter (EKF), and was used as the

Isaac Miller; Mark Campbell

2012-01-01

79

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

80

Urban/Indoor Navigation Using Network Assisted GPS.  

National Technical Information Service (NTIS)

GPS information is an essential element of network centric warfare providing key positioning and timing information in support of communication, positioning and navigation functions. For these networked GPS applications, it is also possible to improve the...

A. K. Brown P. Olson

2006-01-01

81

GPS/MEMS IMU/Microprocessor Board for Navigation  

NASA Technical Reports Server (NTRS)

A miniaturized instrumentation package comprising a (1) Global Positioning System (GPS) receiver, (2) an inertial measurement unit (IMU) consisting largely of surface-micromachined sensors of the microelectromechanical systems (MEMS) type, and (3) a microprocessor, all residing on a single circuit board, is part of the navigation system of a compact robotic spacecraft intended to be released from a larger spacecraft [e.g., the International Space Station (ISS)] for exterior visual inspection of the larger spacecraft. Variants of the package may also be useful in terrestrial collision-detection and -avoidance applications. The navigation solution obtained by integrating the IMU outputs is fed back to a correlator in the GPS receiver to aid in tracking GPS signals. The raw GPS and IMU data are blended in a Kalman filter to obtain an optimal navigation solution, which can be supplemented by range and velocity data obtained by use of (l) a stereoscopic pair of electronic cameras aboard the robotic spacecraft and/or (2) a laser dynamic range imager aboard the ISS. The novelty of the package lies mostly in those aspects of the design of the MEMS IMU that pertain to controlling mechanical resonances and stabilizing scale factors and biases.

Gender, Thomas K.; Chow, James; Ott, William E.

2009-01-01

82

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

83

Navigation systems  

NASA Astrophysics Data System (ADS)

The elements of the measurement and communications network comprising the global deep space navigation system (DSN) for NASA missions are described. Among the measurement systems discussed are: VLBI, two-way Doppler and range measurements, and optical measurements carried out on board the spacecraft. Processing of navigation measurement is carried out using two modules: an N-body numerical integration of the trajectory (and state transition partial derivatives) based on pre-guessed initial conditions; and partial derivatives of simulated observables corresponding to each actual observation. Calculations of velocity correction parameters is performed by precise modelling of all physical phenomena influencing the observational measurements, including: planetary motions; tracking station locations, gravity field structure, and transmission media effects. Some of the contributions to earth-relative orbit estimate errors for the Doppler/range system on board Voyager are discussed in detail. A line drawing of the DSN navigation system is provided.

Jordan, J. F.

1985-10-01

84

The determination of navigation information for space vehicle by GPS (or INS)/equations of motion  

NASA Astrophysics Data System (ADS)

Based on the norminal trajectory of aeroassisted orbital transfer, the paper gives a new navigation scheme for the space vehicle. Navigation hardware/Equation of Motion (EM). Global Positioning System (GPS)/EM, INS/EM are studied for the vehicle to determine the navigation information (such as position, velocity, attitude, and so on) during aeroassisted orbital transfer. Supersonic aerodynamic calculation formulas are introduced to deduce the equations of the filter and observation for the hybrid navigation systems. The numerical results show that the navigation precision of GPS (or INS)/EM are higher than the one of single EM, GPS (or INS). The GPS (or INS)/EM has more redundancy than the single GPS (or INS).

Ying, Nan

85

GPS Navigation for the Magnetospheric Multi-Scale Mission  

NASA Technical Reports Server (NTRS)

In 2014. NASA is scheduled to launch the Magnetospheric Multiscale Mission (MMS), a four-satellite formation designed to monitor fluctuations in the Earth's magnetosphere. This mission has two planned phases with different orbits (1? x 12Re and 1.2 x 25Re) to allow for varying science regions of interest. To minimize ground resources and to mitigate the probability of collisions between formation members, an on-board orbit determination system consisting of a Global Positioning System (GPS) receiver and crosslink transceiver was desired. Candidate sensors would be required to acquire GPS signals both below and above the constellation while spinning at three revolutions-per-minute (RPM) and exchanging state and science information among the constellation. The Intersatellite Ranging and Alarm System (IRAS), developed by Goddard Space Flight Center (GSFC) was selected to meet this challenge. IRAS leverages the eight years of development GSFC has invested in the Navigator GPS receiver and its spacecraft communication expertise, culminating in a sensor capable of absolute and relative navigation as well as intersatellite communication. The Navigator is a state-of-the-art receiver designed to acquire and track weak GPS signals down to -147dBm. This innovation allows the receiver to track both the main lobe and the much weaker side lobe signals. The Navigator's four antenna inputs and 24 tracking channels, together with customized hardware and software, allow it to seamlessly maintain visibility while rotating. Additionally, an extended Kalman filter provides autonomous, near real-time, absolute state and time estimates. The Navigator made its maiden voyage on the Space Shuttle during the Hubble Servicing Mission, and is scheduled to fly on MMS as well as the Global Precipitation Measurement Mission (GPM). Additionally, Navigator's acquisition engine will be featured in the receiver being developed for the Orion vehicle. The crosslink transceiver is a 1/4 Watt transmitter utilizing a TDMA schedule to distribute a science quality message to all constellation members every ten seconds. Additionally the system generates one-way range measurements between formation members which is used as input to the Kalman filter. In preparation for the MMS Preliminary Design Review (PDR), the Navigator was required to pass a series of Technology Readiness Level (TRL) tests to earn the necessary TRL-6 classification. The TRL-6 level is achieved by demonstrating a prototype unit in a relevant end-to-end environment. The IRAS unit was able to meet all requirements during the testing phase, and has thus been TRL-6 qualified

Bamford, William; Mitchell, Jason; Southward, Michael; Baldwin, Philip; Winternitz, Luke; Heckler, Gregory; Kurichh, Rishi; Sirotzky, Steve

2009-01-01

86

Navigation and GPS Based Path Control of an Autonomous Vehicle  

Microsoft Academic Search

\\u000a In this work the navigation and GPS based trajectory control of an unmanned autonomous vehicle is introduced. The caterpillar\\u000a tread like mobile vehicle with duo cycle drive is equipped with a mobile GPS and micro controller. To get accurate position\\u000a data, a DGPS (Differential GPS) with a local base station is used. In order to let the vehicle to follow

Erol Uyar; Levent Çetin; Aytaç Gören

2005-01-01

87

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

88

Estimation of time delay of INS\\/GPS navigation in airborne gravity  

Microsoft Academic Search

For high accurate applications of integration of the Inertial Navigation System (INS) and the Global Positioning System (GPS) like airborne gravity, time synchronization is of great importance. In this paper, we apply an augmented Kalman filter method with a state representing the timing error between GPS and INS. The detail deduce of the augmented Kalman filter is presented. Simulation shows

Yangming Huang; Kaidong Zhang; Bing Luo

2009-01-01

89

Influence of Dynamics and Trajectory on Integrated GPS\\/INS Navigation Performance  

Microsoft Academic Search

The integrated GPS\\/INS system has become an indispensable tool for providing precise and continuous position, velocity, and attitude information for many positioning and navigation applications. Therefore, it is important to gain insights into the characteristics of the integrated GPS\\/INS system performance, particularly their relationships with key operational factors, such as the trajectory and dynamics. Such knowledge can be used to

J. Wang; H. K. Lee; S. Hewitson; Hyung-Keun Lee

2003-01-01

90

A GPS Receiver for High-Altitude Satellite Navigation  

Microsoft Academic Search

Although GPS has found wide application for precision spacecraft navigation and formation flying applications in low Earth orbit (LEO), its application to geosynchronous (GEO) and other high-altitude missions has been limited to an experimental role because of the sparsity and weakness of the GPS signals present there. To fill this gap, NASA Goddard Space Flight Center (GSFC) has developed a

Luke M. B. Winternitz; William A. Bamford; Gregory W. Heckler

2009-01-01

91

Inertial navigation aided with GPS information  

Microsoft Academic Search

This paper presents a dynamic alignment algorithm for a six-degree of freedom inertial unit. A differential GPS is used as external sensor. It provides decorrelated range position and Doppler velocity information. A simplified error model valid for a local area is also presented. An indirect Kalman filter approach is used to fuse high frequency inertial information with low frequency GPS

E. Nebot; S. Sukkarieh; H. Durrant-Whyte

1997-01-01

92

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

Microsoft Academic Search

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

Korak Saha; Suresh Raju C; Krishnaswamy Parameswaran

2008-01-01

93

A Regional Tropospheric Delay Model for GPS Based Aircraft Navigation over Indian Subcontinent  

Microsoft Academic Search

A Region-specific Tropospheric Delay model for GPS based aircraft navigation is developed exclusively for the Indian region and its applicability is examined by comparing estimated zenith tropospheric delay (ZTD) with those from other regional models based on measured surface atmospheric parameters, and with global model used in Wide Area Augmentation System as well as with GPS measured ZTD values. This

Korak Saha; C. Suresh Raju; K. Parameswaran

94

Navigation accuracy and interference rejection for GPS adaptive antenna arrays  

NASA Astrophysics Data System (ADS)

The classic problem in signal processing is to enhance signal while suppressing noise. In this investigation, the signal is timing information from satellites of the Global Positioning System (GPS). The noise originates from jammers at disparate locations. The first step in the solution is to develop a software receiver that implements an adaptive directional antenna array which points (electronically) to individual GPS satellites while suppressing jammers. This software receiver and the associated space-time adaptive algorithms represent a robust and efficient architecture for follow-on hardware implementation. The second step is to analyze the tradeoff between allocating resources to reject radio frequency interference and allocating resources to mitigate measurement biases in the GPS timing information. This analysis leads to deterministic corrections that reduce navigation biases to acceptable levels while preserving the interference rejection capabilities of the adaptive array. The final step is experimental verification by exercising the software receiver with operational hardware in the loop. This investigation demonstrates that adaptive antenna arrays can enable systems that meet the aggressive accuracy and integrity requirements for piloted and autonomous aircraft landing while simultaneously providing significant attenuation of radio frequency interference.

de Lorenzo, David S.

95

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

96

A LEO Satellite Navigation Algorithm Based on GPS and Magnetometer Data  

NASA Technical Reports Server (NTRS)

The Global Positioning System (GPS) has become a standard method for low cost onboard satellite orbit determination. The use of a GPS receiver as an attitude and rate sensor has also been developed in the recent past. Additionally, focus has been given to attitude and orbit estimation using the magnetometer, a low cost, reliable sensor. Combining measurements from both GPS and a magnetometer can provide a robust navigation system that takes advantage of the estimation qualities of both measurements. Ultimately a low cost, accurate navigation system can result, potentially eliminating the need for more costly sensors, including gyroscopes.

Deutschmann, Julie; Bar-Itzhack, Itzhack; Harman, Rick; Bauer, Frank H. (Technical Monitor)

2000-01-01

97

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

98

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

99

Indoor/Outdoor Seamless Positioning Using Lighting Tags and GPS Cellular Phones for Personal Navigation  

NASA Astrophysics Data System (ADS)

The authors focused on the development of an indoor positioning system which is easy to use, portable and available for everyone. This system is capable of providing the correct position anywhere indoors, including onboard ships, and was invented in order to evaluate the availability of GPS indoors. Although the performance of GPS is superior outdoors, there has been considerable research regarding indoor GPS involving sensitive GPS, pseudolites (GPS pseudo satellite), RFID (Radio Frequency IDentification) tags, and wireless LAN .However, the positioning rate and the precision are not high enough for general use, which is the reason why these technologies have not yet spread to personal navigation systems. In this regard, the authors attempted to implement an indoor positioning system using cellular phones with built-in GPS and infrared light data communication functionality, which are widely used in Japan. GPS is becoming increasingly popular, where GPGGS sentences of the NMEA outputted from the GPS receiver provide spatiotemporal information including latitude, longitude, altitude, and time or ECEF xyz coordinates. As GPS applications grow rapidly, spatiotemporal data becomes key to the ubiquitous outdoor and indoor seamless positioning services at least for the entire area of Japan, as well as to becoming familiar with satellite positioning systems (e.g. GPS). Furthermore, the authors are also working on the idea of using PDAs (Personal Digital Assistants), as cellular phones with built-in GPS and PDA functionality are also becoming increasingly popular.

Namie, Hiromune; Morishita, Hisashi

100

Integrating GIS and GPS to realise autonomous navigation of farm machinery  

Microsoft Academic Search

Path planning is a key technique to realise autonomous navigation of farm machines. Based on MapObjects, a Geographic Information System (GIS) for autonomous navigation was developed with Visual C++. A path search algorithm used to guide machines to track the desired path was designed. A Global Positioning System (GPS) was adopted in this algorithm to determine the current position of

Meng Xiangjian; Liu Gang

2007-01-01

101

A Leo Satellite Navigation Algorithm Based on GPS and Magnetometer Data  

NASA Technical Reports Server (NTRS)

The Global Positioning System (GPS) has become a standard method for low cost onboard satellite orbit determination. The use of a GPS receiver as an attitude and rate sensor has also been developed in the recent past. Additionally, focus has been given to attitude and orbit estimation using the magnetometer, a low cost, reliable sensor. Combining measurements from both GPS and a magnetometer can provide a robust navigation system that takes advantage of the estimation qualities of both measurements. Ultimately, a low cost, accurate navigation system can result, potentially eliminating the need for more costly sensors, including gyroscopes. This work presents the development of a technique to eliminate numerical differentiation of the GPS phase measurements and also compares the use of one versus two GPS satellites.

Deutschmann, Julie; Harman, Rick; Bar-Itzhack, Itzhack

2001-01-01

102

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

103

Sole means navigation and integrity through hybrid Loran-C and NAVSTAR GPS  

NASA Technical Reports Server (NTRS)

A sole means navigation system does not only call for integrity, but also for coverage, reliability, availability and accuracy. Even though ground monitored GPS will provide integrity, availability is still not sufficient. One satellite outage can affect a large service area for several hours per day. The same holds for differential GPS; a total satellite outage cannot be corrected for. To obtain sufficient coverage, extra measurements are needed, either in the form of extra GPS satellites (expensive) or through redundant measurements from other systems. LORAN-C is available and will, hybridized with GPS, result in a system that has the potential to satisfy the requirements for a sole means navigation system for use in the continental United States. Assumptions are made about the qualification sole means, mainly based on current sole means systems such as VOR/DME. In order to allow for system design that will satisfy sole means requirements, it is recommended that a definition of a sole means navigation system be established. This definition must include requirements for availability, reliability, and integrity currently not specified. In addition to the definition of a sole means navigation system, certification requirements must be established for hybrid navigation systems. This will allow for design and production of a new generation of airborne navigation systems that will reduce overall system costs and simplify training procedures.

Vangraas, Frank

1990-01-01

104

Large magnetic storm-induced nighttime ionospheric flows at midlatitudes and their impacts on GPS-based navigation systems  

Microsoft Academic Search

Analysis of GPS phase fluctuations in conjunction with regional total electron content (TEC) maps, in situ measurements of subauroral polarization streams (SAPS) and auroral convection from several Defense Meteorological Satellite Program spacecraft, and dynasonde measurements at the Bear Lake Observatory obtained during the intense magnetic storm of 7–8 November 2004 have indicated the serious impact of large ionospheric velocities on

Su. Basu; S. Basu; E. MacKenzie; P. Doherty; J. W. Wright; F. Rich; M. J. Keskinen; R. E. Sheehan

2008-01-01

105

GPS system simulation methodology  

Microsoft Academic Search

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

Thomas F. Ewing

1993-01-01

106

Hybrid Navigation Systems.  

National Technical Information Service (NTIS)

Contents: Hybrid guidance and navigation systems; Characteristics of a satellite navigation system operated in conjunction with a user inertial system; Global navigation/traffic surveillance/communication satellite system for military and civil vehicles; ...

G. R. Marner, B. P. Leonard, M. W. Mitchell, F. S. Stringer, M. G. Pearson

1970-01-01

107

GPS World, Innovation: Autonomous Navigation at High Earth Orbits  

NASA Technical Reports Server (NTRS)

Calculating a spacecraft's precise location at high orbital altitudes-22,000 miles (35,800 km) and beyond-is an important and challenging problem. New and exciting opportunities become possible if satellites are able to autonomously determine their own orbits. First, the repetitive task of periodically collecting range measurements from terrestrial antennas to high altitude spacecraft becomes less important-this lessens competition for control facilities and saves money by reducing operational costs. Also, autonomous navigation at high orbital altitudes introduces the possibility of autonomous station keeping. For example, if a geostationary satellite begins to drift outside of its designated slot it can make orbit adjustments without requiring commands from the ground. Finally, precise onboard orbit determination opens the door to satellites flying in formation-an emerging concept for many scientific space applications. The realization of these benefits is not a trivial task. While the navigation signals broadcast by GPS satellites are well suited for orbit and attitude determination at lower altitudes, acquiring and using these signals at geostationary (GEO) and highly elliptical orbits is much more difficult. The light blue trace describes the GPS orbit at approximately 12,550 miles (20,200 km) altitude. GPS satellites were designed to provide navigation signals to terrestrial users-consequently the antenna array points directly toward the earth. GEO and HE0 orbits, however, are well above the operational GPS constellation, making signal reception at these altitudes more challenging. The nominal beamwidth of a Block II/IIA GPS satellite antenna array is approximately 42.6 degrees. At GEO and HE0 altitudes, most of these primary beam transmissions are blocked by the Earth, leaving only a narrow region of nominal signal visibility near opposing limbs of the earth. This region is highlighted in gray. If GPS receivers at GEO and HE0 orbits were designed to use these higher power signals only, precise orbit determination would not be practical. Fortunately, the GPS satellite antenna array also produces side lobe signals at much lower power levels. NASA has designed and tested the Navigator, a new GPS receiver that can acquire and track these weaker signals, thereby dramatically increasing the signal visibility at these altitudes. While using much weaker signals is a fundamental requirement for a high orbital altitude GPS receiver, it is certainly not the only challenge. There are other unique characteristics of this application that must also be considered. For example, Position Dilution of Precision (PDOP) figures are much higher at GEO and HE0 altitudes because visible GPS satellites are concentrated in a much smaller area with respect to the spacecraft antenna. These poor PDOP values contribute considerable error to the point solutions calculated by the spacecraft GPS receiver. Finally, spacecraft GPS receivers must be designed to withstand a variety of extreme environmental conditions. Variations in acceleration between launch and booster separation are extreme. Temperature gradients in the space environment are also severe. Furthermore, radiation effects are a major concern-spacecraft-borne GPS receivers must be designed with radiation-hardened electronics to guard against this phenomenon, otherwise they simply will not work. Perhaps most importantly, there are no opportunities to repair or modify any space-borne GPS receiver after it has been launched. Great care must be taken to ensure all performance characteristics have been analyzed prior to liftoff.

Bamford, William; Winternitz, Luke; Hay, Curtis

2005-01-01

108

EM-IMM based land-vehicle navigation with GPS\\/INS  

Microsoft Academic Search

Integration of the global positioning system (GPS) with the inertial navigation system (INS) is favorable since it provides enhanced positioning accuracy. Its implementation is essentially based on the standard Kalman filter techniques. However, the estimation accuracy is degraded if unknown parameters present in the system model or the model changes with the environment as in the case of intelligent transportation

Dongliang Huang; Henry Leung

2004-01-01

109

Multi-Flight-Phase GPS Navigation Filter Applications to Terrestrial Vehicle Navigation and Positioning  

NASA Technical Reports Server (NTRS)

A candidate onboard space navigation filter demonstrated excellent performance (less than 8 meter level RMS semi-major axis accuracy) in performing orbit determination of a low-Earth orbit Explorer satellite using single-frequency real GPS data. This performance is significantly better than predicted by other simulation studies using dual-frequency GPS data. The study results revealed the significance of two new modeling approaches evaluated in the work. One approach introduces a single-frequency ionospheric correction through pseudo-range and phase range averaging implementation. The other approach demonstrates a precise axis-dependent characterization of dynamic sample space uncertainty to compute a more accurate Kalman filter gain. Additionally, this navigation filter demonstrates a flexibility to accommodate both perturbational dynamic and observational biases required for multi-flight phase and inhomogeneous application environments. This paper reviews the potential application of these methods and the filter structure to terrestrial vehicle and positioning applications. Both the single-frequency ionospheric correction method and the axis-dependent state noise modeling approach offer valuable contributions in cost and accuracy improvements for terrestrial GPS receivers. With a modular design approach to either 'plug-in' or 'unplug' various force models, this multi-flight phase navigation filter design structure also provides a versatile GPS navigation software engine for both atmospheric and exo-atmospheric navigation or positioning use, thereby streamlining the flight phase or application-dependent software requirements. Thus, a standardized GPS navigation software engine that can reduce the development and maintenance cost of commercial GPS receivers is now possible.

Park, Young W.; Montez, Moises N.

1994-01-01

110

Development of Aerial Photogrammetric Navigation by GPS.  

National Technical Information Service (NTIS)

The objective of this research was to implement a similar photo-nav system for ODOT, tailored to the larger scale characteristics of the ODOT photo missions. Drawing on these developments, the ODOT photogrammetric system, which includes a geodetic quality...

D. C. Merchant

1997-01-01

111

Development And Test of A Digitally Steered Antenna Array for The Navigator GPS Receiver  

NASA Technical Reports Server (NTRS)

Global Positioning System (GPS)-based navigation has become common for low-Earth orbit spacecraft as the signal environment is similar to that on the Earth s surface. The situation changes abruptly, however, for spacecraft whose orbital altitudes exceed that of the GPS constellation. Visibility is dramatically reduced and signals that are present may be very weak and more susceptible to interference. GPS receivers effective at these altitudes require increased sensitivity, which often requires a high-gain antenna. Pointing such an antenna can pose a challenge. One efficient approach to mitigate these problems is the use of a digitally steered antenna array. Such an antenna can optimally allocate gain toward desired signal sources and away from interferers. This paper presents preliminary results in the development and test of a digitally steered antenna array for the Navigator GPS research program at NASA s Goddard Space Flight Center. In particular, this paper highlights the development of an array and front-end electronics, the development and test of a real-time software GPS receiver, and implementation of three beamforming methods for combining the signals from the array. Additionally, this paper discusses the development of a GPS signal simulator which produces digital samples of the GPS L1C/A signals as they would be received by an arbitrary antenna array configuration. The simulator models transmitter and receiver dynamics, near-far and multipath interference, and has been a critical component in both the development and test of the GPS receiver. The GPS receiver system was tested with real and simulated GPS signals. Preliminary results show that performance improvement was achieved in both the weak signal and interference environments, matching analytical predictions. This paper summarizes our initial findings and discusses the advantages and limitations of the antenna array and the various beamforming methods.

Pinto, Heitor David; Valdez, Jennifer E.; Winternitz, Luke M. B.; Hassouneh, Munther A.; Price, Samuel R.

2012-01-01

112

Robust Real-Time Wide-Area Differential GPS Navigation  

NASA Technical Reports Server (NTRS)

The present invention provides a method and a device for providing superior differential GPS positioning data. The system includes a group of GPS receiving ground stations covering a wide area of the Earth's surface. Unlike other differential GPS systems wherein the known position of each ground station is used to geometrically compute an ephemeris for each GPS satellite. the present system utilizes real-time computation of satellite orbits based on GPS data received from fixed ground stations through a Kalman-type filter/smoother whose output adjusts a real-time orbital model. ne orbital model produces and outputs orbital corrections allowing satellite ephemerides to be known with considerable greater accuracy than from die GPS system broadcasts. The modeled orbits are propagated ahead in time and differenced with actual pseudorange data to compute clock offsets at rapid intervals to compensate for SA clock dither. The orbital and dock calculations are based on dual frequency GPS data which allow computation of estimated signal delay at each ionospheric point. These delay data are used in real-time to construct and update an ionospheric shell map of total electron content which is output as part of the orbital correction data. thereby allowing single frequency users to estimate ionospheric delay with an accuracy approaching that of dual frequency users.

Yunck, Thomas P. (Inventor); Bertiger, William I. (Inventor); Lichten, Stephen M. (Inventor); Mannucci, Anthony J. (Inventor); Muellerschoen, Ronald J. (Inventor); Wu, Sien-Chong (Inventor)

1998-01-01

113

NEW INTELLIGENT METHOD TO GENERATE VECTOR MAPS FOR GPS NAVIGATION  

Microsoft Academic Search

This paper introduces a new intelligent method to generate vector maps from printed maps to provide a basis for GPS navigation. This new approach has been applied in our GIS-DMG (Digital Map Generation) software, which has four key steps: Map Layers Extraction, Road Network Digitalization, Map Geo-locating and Map Automatic Geo-adjusting, different from typical procedures. These four steps play essential

Sheng-Guo Wang; Yuanlu Bao

114

Applications of Clocks to Space Navigation & "Planetary GPS"  

NASA Technical Reports Server (NTRS)

The ability to fly atomic clocks on GPS satellites has profoundly defined the capabilities and limitations of GPS in near-Earth applications. It is likely that future infrastructure for Lunar and Mars applications will be constrained by financial factors. The development of a low cost, small, high performance space clock -- or ultrahigh performance space clocks -- could revolutionize and drive the entire approach to GPS-like systems at the Moon (or Mars), and possibly even change the future of GPS at Earth. Many system trade studies are required. The performance of future GPS-like tracking systems at the Moon or Mars will depend critically on clock performance, availability of inertial sensors, and constellation coverage. Example: present-day GPS carry 10(exp -13) clocks and require several updates per day. With 10(exp -15) clocks, a constellation at Mars could operate autonomously with updates just once per month. Use of GPS tracking at the Moon should be evaluated in a technical study.

Lichten, Stephen M.

2004-01-01

115

Receiver autonomous integrity monitoring (RAIM) capability for sole-means GPS navigation in the oceanic phase of flight  

Microsoft Academic Search

The author analyzes GPS (Global Positioning System) RAIM capability for sole-means navigation in the oceanic phase of flight, where the position protection limit requirement for the integrity function is not as stringent as for nonprecision approaches, and yet both detection and identification functions may be required if GPS is to be used as a sole-means system. For this purpose, a

Young C. Lee

1992-01-01

116

Differential GPS/inertial navigation approach/landing flight test results  

NASA Technical Reports Server (NTRS)

In November of 1990 a joint Honeywell/NASA-Langley differential GPS/inertial flight test was conducted at Wallops Island, Virginia. The test objective was to acquire a system performance database and demonstrate automatic landing using an integrated differential GPS/INS (Global Positioning System/inertial navigation system) with barometric and radar altimeters. The flight test effort exceeded program objectives with over 120 landings, 36 of which were fully automatic differential GPS/inertial landings. Flight test results obtained from post-flight data analysis are discussed. These results include characteristics of differential GPS/inertial error, using the Wallops Island Laser Tracker as a reference. Data on the magnitude of the differential corrections and vertical channel performance with and without radar altimeter augmentation are provided.

Snyder, Scott; Schipper, Brian; Vallot, Larry; Parker, Nigel; Spitzer, Cary

1992-01-01

117

Orbit Relative Navigation and Proximity Sensing Using a GPS Bi- static Radar.  

National Technical Information Service (NTIS)

The objective of the work described was to build a nanosat as part for the UNP-6 competition cycle to demonstrate the use of the Global Positioning System (GPS) as passive bistatic radar for on-orbit relative navigation, proximity detection and remote sen...

D. Gebre-Egziabher

2011-01-01

118

Results from Navigator GPS Flight Testing for the Magnetospheric MultiScale Mission  

NASA Technical Reports Server (NTRS)

The recent delivery of the first Goddard Space Flight Center (GSFC) Navigator Global Positioning System (GPS) receivers to the Magnetospheric MultiScale (MMS) mission spacecraft is a high water mark crowning a decade of research and development in high-altitude space-based GPS. Preceding MMS delivery, the engineering team had developed receivers to support multiple missions and mission studies, such as Low Earth Orbit (LEO) navigation for the Global Precipitation Mission (GPM), above the constellation navigation for the Geostationary Operational Environmental Satellite (GOES) proof-of-concept studies, cis-Lunar navigation with rapid re-acquisition during re-entry for the Orion Project and an orbital demonstration on the Space Shuttle during the Hubble Servicing Mission (HSM-4).

Lulick, Tyler D.; Bamford, William A.; Wintermitz, Luke M. B.; Price, Samuel R.

2012-01-01

119

An Assessment of the RAIM Performance of a Combined Galileo\\/GPS Navigation System Using the Marginally Detectable Errors (MDE) Algorithm  

Microsoft Academic Search

  Integrity relates to the trust that can be placed in the correctness of information supplied by a navigation system. It includes\\u000a the ability of the navigation system to provide timely warning to users when the system fails to meet its stated accuracy.\\u000a Specifically, a navigation system is required to deliver a warning (alarm) when the error in the derived user

W. Y. Ochieng; K. F. Sheridan; K. Sauer; X. Han; P. A. Cross; S. Lannelongue; N. Ammour; K. Petit

2002-01-01

120

A LEO Satellite Navigation Algorithm Based on GPS and Magnetometer Data  

NASA Technical Reports Server (NTRS)

The Global Position System (GPS) has become a standard method for low cost onboard satellite orbit determination. The use of GPS as an attitude and rate sensor has also been developed in the recent past. Additionally, focus has been given to attitude and orbit estimation using the magnetometer, a low cost, reliable sensor. Combining measurements from both GPS and a magnetometer can provide a robust navigation system which takes advantage of the estimation qualities of both measurements. Ultimately a low cost, accurate navigation system can result, potentially eliminating the need for more costly sensors, including gyroscopes. This work presents the development and preliminary testing of a unified navigation algorithm which produces estimates of attitude, angular rate, position, and velocity for a low earth orbit (LEO) spacecraft. The system relies on GPS phase, range, and range rate data as well as magnetometer data. The algorithm used is an extended Kalman filter (EKF) developed to provide LEO attitude, orbit, and rate estimates using magnetometer and sun sensor data. Incorporating sun sensor data into the EKF improved the attitude and rate estimates. For many LEO spacecraft the sun data is available during only a portion of the orbit. However, GPS data is available continuously throughout the orbit. GPS can produce accurate orbit estimates and combining GPS and magnetometer data improves the attitude and rate estimates. The magnetometer based EKF can converge from large initial errors in position, velocity, and 3 attitude . Combining the magnetometer and GPS data into a single EKF will provide a more robust and accurate system. The EKF is based on an existing EKF. The GPS measurement models for phase, range, and range rate are incorporated into the existing structure of the filter. The original EKF produced the orbit estimates in terms of Keplerian elements. Due to the nature of the GPS measurements and ease of computation, the orbit estimates are converted to the Cartesian position and velocity. The measurement model for the magnetometer is adjusted for this change in the state and the measurements. Preliminary test results based on simulated GPS and magnetometer data are included.

Deutschmann, Julie; Bar-Itzhack, Itzhack Y.; Harman, Rick

2000-01-01

121

Tactical underwater navigation system (TUNS)  

Microsoft Academic Search

The problem of underwater navigation for an individual diver is particularly challenging. GPS navigation is unsuitable for most underwater operations and particularly covert operations use because the GPS RF signal is attenuated below usable levels as it penetrates the water column. Dead reckoning methods, which rely on magnetic compass and approximate distance measurements, are susceptible to magnetic interference, inaccurate distance

R. Hartman; W. Hawkinson; K. Sweeney

2008-01-01

122

ChemGPS-NP(Web): chemical space navigation online.  

PubMed

Internet has become a central source for information, tools, and services facilitating the work for medicinal chemists and drug discoverers worldwide. In this paper we introduce a web-based public tool, ChemGPS-NP(Web) (http://chemgps.bmc.uu.se), for comprehensive chemical space navigation and exploration in terms of global mapping onto a consistent, eight dimensional map over structure derived physico-chemical characteristics. ChemGPS-NP(Web) can assist in compound selection and prioritization; property description and interpretation; cluster analysis and neighbourhood mapping; as well as comparison and characterization of large compound datasets. By using ChemGPS-NP(Web), researchers can analyze and compare chemical libraries in a consistent manner. In this study it is demonstrated how ChemGPS-NP(Web) can assist in interpreting results from two large datasets tested for activity in biological assays for pyruvate kinase and Bcl-2 family related protein interactions, respectively. Furthermore, a more than 30-year-old suggestion of "chemical similarity" between the natural pigments betalains and muscaflavins is tested. PMID:19082743

Rosén, Josefin; Lövgren, Anders; Kogej, Thierry; Muresan, Sorel; Gottfries, Johan; Backlund, Anders

2009-04-01

123

Benefits of combined GPS/GLONASS with low-cost MEMS IMUs for vehicular urban navigation.  

PubMed

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. PMID:22666079

Angrisano, Antonio; Petovello, Mark; Pugliano, Giovanni

2012-01-01

124

Landsat/4/Global Positioning System navigation results  

NASA Technical Reports Server (NTRS)

An experimental GPSPAC flown on the Landsat-4 spacecraft was the first spaceborne navigation system to use the NAVSTAR Global Position System (GPS). In order to validate the accuracy and reliability of GPSPAC orbit solutions, definitive Landsat-4 ephemerides, derived from ground based tracking data, were generated and compared with GPSPAC estimates. In addition, Landsat-4 orbital solutions were reconstructed from raw GPS measurement data with a GPSPAC navigation simulator program using different Kalman filter constants. Ephemeris comparisons and simulator results are presented, as well as recommendations for the navigation filter.

Heuberger, H.; Church, L.

1984-01-01

125

A New Centimeter-Level Real-Time Global Navigation and Positioning Capability with GPS  

NASA Technical Reports Server (NTRS)

NASA/JPL has developed a new, precise, global, GPS-based capability for real-time terrestrial and space platform navigation. It has been demonstrated on Earth's surface and is 10 times more accurate than other real-time GPS-based systems. The new system poses certain advantages for Earth science remote sensing, including: the onboard generation of science data products in real-time, sensor control and reduction of data transmission bandwidth, improved environmental forecasting, autonomous and intelligent platform control, operations cost savings, and technology transfer and commercial partnership opportunities. The system's measurement capabilities and applications, demonstrated orbit accuracies, and precision LEO and spacecraft positioning and timing are highlighted.

Bar-Sever, Yoaz

2001-01-01

126

Networked differential GPS system  

NASA Technical Reports Server (NTRS)

An embodiment of the present invention relates to a worldwide network of differential GPS reference stations (NDGPS) that continually track the entire GPS satellite constellation and provide interpolations of reference station corrections tailored for particular user locations between the reference stations Each reference station takes real-time ionospheric measurements with codeless cross-correlating dual-frequency carrier GPS receivers and computes real-time orbit ephemerides independently. An absolute pseudorange correction (PRC) is defined for each satellite as a function of a particular user's location. A map of the function is constructed, with iso-PRC contours. The network measures the PRCs at a few points, so-called reference stations and constructs an iso-PRC map for each satellite. Corrections are interpolated for each user's site on a subscription basis. The data bandwidths are kept to a minimum by transmitting information that cannot be obtained directly by the user and by updating information by classes and according to how quickly each class of data goes stale given the realities of the GPS system. Sub-decimeter-level kinematic accuracy over a given area is accomplished by establishing a mini-fiducial network.

Mueller, K. Tysen (Inventor); Loomis, Peter V. W. (Inventor); Kalafus, Rudolph M. (Inventor); Sheynblat, Leonid (Inventor)

1994-01-01

127

High Assurance GPS Integrity Monitoring System Using Particle Filtering Approach  

Microsoft Academic Search

The reliability of a navigation system is one of the critical requirements for air or automotive navigation. In order to increase the reliability of the navigation system, failures or faults resulting from the malfunctions of the system should be detected and repaired to keep the system possessing high integrity. This leads to a need for developing high assurance GPS monitoring

Jeong-Oog Lee; Dae Hee Won; Sangkyung Sung; Tae Sam Kang; Young Jae Lee

2007-01-01

128

Autonomous integrated GPS/INS navigation experiment for OMV. Phase 1: Feasibility study  

NASA Technical Reports Server (NTRS)

The phase 1 research focused on the experiment definition. A tightly integrated Global Positioning System/Inertial Navigation System (GPS/INS) navigation filter design was analyzed and was shown, via detailed computer simulation, to provide precise position, velocity, and attitude (alignment) data to support navigation and attitude control requirements of future NASA missions. The application of the integrated filter was also shown to provide the opportunity to calibrate inertial instrument errors which is particularly useful in reducing INS error growth during times of GPS outages. While the Orbital Maneuvering Vehicle (OMV) provides a good target platform for demonstration and for possible flight implementation to provide improved capability, a successful proof-of-concept ground demonstration can be obtained using any simulated mission scenario data, such as Space Transfer Vehicle, Shuttle-C, Space Station.

Upadhyay, Triveni N.; Priovolos, George J.; Rhodehamel, Harley

1990-01-01

129

Use of GPS (Global Positioning System) for Dynamic Positioning of Hydrographic Survey Platforms.  

National Technical Information Service (NTIS)

The Navstar Global Positioning System (GPS) is a satellite-based radio navigation system designed to provide continuous all-weather navigation to appropriately equipped users on a worldwide basis. The NAVSTAR system of navigation satellites may be exploit...

P. J. Fell W. H. Wooden

1986-01-01

130

Design of Integrated Navigation System Based on Information Fusion Technology for the Intelligent Transportation System  

Microsoft Academic Search

In recent years there has been a major upsurge of interest in the integrated global positioning system (GPS)\\/inertial navigation system (INS) as a cost-effective way of providing accurate and reliable navigation aid for civil and military vehicles. This thesis discusses the technology problem and calculation methods of GPS\\/INS integrated navigation system. The GPS\\/INS integrated navigation system based on information fusion

Cao Jie; Chen Shaoshan; Li Yu; Ren Chongyu

2006-01-01

131

Carrier Phase GPS Navigation to the North Pole  

NASA Astrophysics Data System (ADS)

Over the last few years, on-the-fly integer ambiguity resolution for GPS has proven to be successful over short baselines (<20 km). However, the remaining challenge has been to extend the length of the baseline between the reference station and the mobile receiver, whilst still maintaining the capability of on-the-fly resolution and true carrier-based kinematic positioning. The goal has been to achieve centimetric level positioning at ranges of over 500 km. New techniques have been developed at the University of Nottingham to allow very long baseline integer ambiguity resolution, on-the-fly. A major problem with the use of carrier phase data is that posed by cycle slips. A technique for detecting and correcting cycle slips has been developed, and its use is discussed in this paper. The new technique has been proven through a series of trials, one of which included two flights to the North Pole, performing centimetric level positioning all the way to the pole. For many years, the GD Aero-Systems Course of the Air Warfare Centre based at RAF Cranwell executed a series of equipment flight trials to the North Pole, called the ARIES Flights. In May 1996, the authors were fortunate to take part in both flights, via Iceland and Greenland, to the North Pole. Based on reference stations at Thule Air Base, integer ambiguity resolution was accomplished, on-the-fly, and centimetric level navigation maintained throughout the flights. Earlier trials detailed in the paper demonstrate that the technique can resolve integer ambiguities on-the-fly within a few seconds over a baseline length of approximately 134 km, resulting in an accuracy of 12 cm. The majority of the residual error source for this being the ionosphere.

Moore, T.; Roberts, G. W.

132

Test and Demonstration of GPS Satellite Survey Systems.  

National Technical Information Service (NTIS)

Contents: Summary report on testing and demonstration of TI4100 GPS Navigator satellite survey system and associated processing software; Summary report on test and demonstration of Trimble 4000S satellite survey system and associated processing software;...

L. D. Hothem

1990-01-01

133

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

134

Embedded Low Cost Inertial Navigation System 1  

Microsoft Academic Search

This paper will discuss the design and implementation of an embedded low cost inertial navigation system (INS) using an inertial measurement unit (IMU), digital compass, GPS, and an embedded computer system. The INS is capable of providing continuous estimates of a vehicle's position and orientation. Typically IMU's are very expensive systems, however this INS will use \\

Kevin J. Walchko; Michael C. Nechyba; Eric Schwartz; Antonio Arroyo

135

Testing the Preliminary X-33 Navigation System  

NASA Technical Reports Server (NTRS)

The X-33 Reusable Launch Vehicle (RLV) must meet the demanding requirements of landing autonomously on a narrow landing strip following a flight that reaches an altitude of up to 200,000 feet and a speed in excess of Mach 9 with significant in-flight energy bleed-off maneuvers. To execute this flight regimen a highly reliable avionics system has been designed that includes three LN-100G Inertial Navigation System/Global Positioning System (INS/GPS) units as the primary navigation system for the X-33. NASA's Marshall Space Flight Center (MSFC) tested an INS/GPS system in real-time simulations to determine the ability of this navigation suite to meet the in flight and autonomous landing requirements of the X-33 RLV. A total of sixty-one open loop tests were performed to characterize the navigation accuracy of the LN-100G. Twenty-seven closed-loop tests were also performed to evaluate the performance of the X-33 Guidance, Navigation and Control (GN&C) algorithms with the real navigation hardware. These closed-loop tests were also designed to expose any integration or operational issues with the real-time X-33 vehicle simulation. Dynamic road tests of the INS/GPS were conducted by Litton to assess the performance of differential and nondifferential INS/GPS hybrid navigation solutions. The results of the simulations and road testing demonstrate that this novel solution is capable of meeting the demanding requirements of take-off, in-flight navigation, and autonomous landing of the X-33 RLV. This paper describes the test environment developed to stimulate the LN-100G and discusses the results of this test effort. This paper also presents recommendations for a navigation system suitable to an operational RLV system.

Lomas, James J.; Mitchell, Daniel W.; Freestone, Todd M.; Lee, Charles; Lessman, Craig; Foster, Lee D. (Technical Monitor)

2001-01-01

136

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

137

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

138

Simulation of a navigator algorithm for a low-cost GPS receiver  

NASA Technical Reports Server (NTRS)

The analytical structure of an existing navigator algorithm for a low cost global positioning system receiver is described in detail to facilitate its implementation on in-house digital computers and real-time simulators. The material presented includes a simulation of GPS pseudorange measurements, based on a two-body representation of the NAVSTAR spacecraft orbits, and a four component model of the receiver bias errors. A simpler test for loss of pseudorange measurements due to spacecraft shielding is also noted.

Hodge, W. F.

1980-01-01

139

Application of aircraft navigation sensors to enhanced vision systems  

NASA Technical Reports Server (NTRS)

In this presentation, the applicability of various aircraft navigation sensors to enhanced vision system design is discussed. First, the accuracy requirements of the FAA for precision landing systems are presented, followed by the current navigation systems and their characteristics. These systems include Instrument Landing System (ILS), Microwave Landing System (MLS), Inertial Navigation, Altimetry, and Global Positioning System (GPS). Finally, the use of navigation system data to improve enhanced vision systems is discussed. These applications include radar image rectification, motion compensation, and image registration.

Sweet, Barbara T.

1993-01-01

140

An Inertial Navigation System for Small Autonomous Underwater Vehicles  

Microsoft Academic Search

A small AUV navigation system (SANS) has been developed at the Naval Postgraduate School. The SANS is an integrated GPS\\/INS navigation system composed of low-cost, small-size components. It is designed to demonstrate the feasibility of using a low-cost inertial measurement unit to navigate between intermittent GPS fixes. This paper reports recent improvements to the SANS hardware, latest testing results after

Xiaoping Yun; Eric R. Bachmann; Suat Arslan

2000-01-01

141

GPSIM: A Personal Computer-Based GPS Simulator System  

NASA Astrophysics Data System (ADS)

Global Positioning Systems (GPS) are now in use in many applications, ranging from GIS to route guidance, automatic vehicle location (AVL), air, land, and marine navigation, and many other transportation and geographical based applications. In many applications, the GPS receiver is connected to some form of intelligent electronic system which receives the positional data from the GPS unit and then performs the required operation. When developing and testing GPS-based systems, one of the problems is that it is usually necessary to create GPS-compatible geographical data to simulate a GPS operation in real time. This paper provides the details of a Personal Computer (PC)-based GPS simulator system called GPSIM. The system receives user way-points and routes from Windows-based screen forms and then simulates a GPS operation in real time by generating most of the commonly used GPS sentences. The user-specified waypoints are divided into a number of small segments, each segment specifying a small distance in the direction of the original waypoint. The GPS sentence corresponding to the geographical coordinates of each segment is then sent out of the PC serial port. The system described is an invaluable testing tool for GPS-based system developers and also for people training to learn to use GPS-based products.

Ibrahim, D.

142

Fusion of Sensor Data in Siemens Car Navigation System  

Microsoft Academic Search

Car navigation systems have three main tasks, namely 1) positioning; 2) routing; and 3) navigation (guidance). Positioning of the car is carried out by appropriately combining information from several sensors and information sources, including odometers, gyroscopes, Global Positioning System (GPS) information, and digital maps. This paper describes two sensor-fusion steps implemented in commercial Siemens car navigation systems. The first step

Dragan Obradovic; Henning Lenz; Markus Schupfner

2007-01-01

143

Introduction to Global Navigation Satellite System  

NASA Technical Reports Server (NTRS)

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 a overview and status of other Global Navigation Satellite System (GNSS), specifically GLONASS, Galileo, and QZSS. There is also a review of Satellite based time transfer techniques. The topic is of interest to the Time and Frequency Community, because the Global Positioning system has become the primary system for distributing Time and frequency globally, and because it allows users to synchronize clocks and calibrate and control oscillators in any location that has a GPS antenna.

Moreau, Michael

2005-01-01

144

Inertial navigation systems analysis.  

NASA Technical Reports Server (NTRS)

This volume offers the avionic systems engineer a fundamental exposition of the mechanization and error analysis of inertial navigation systems. While the material is applicable to spacecraft and undersea navigation, emphasis is placed upon terrestrial applications on or slightly above the earth's surface. As a result, practical considerations are geared toward those aircraft navigation systems of particular current interest. Extensive use is made of perturbation techniques to develop linearized system equations, whose solutions closely approximate those obtained by nonlinear differential equations. A unified error analysis technique is developed that is applicable to virtually all system configurations. The technique provides a greatly simplified method for comparing the performance of competing system configurations.

Britting, K. R.

1971-01-01

145

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

146

Gradiometric inertial navigation system.  

NASA Astrophysics Data System (ADS)

Equations are obtained which describe conditions for the perfect operation of a gradiometric inertial navigation system. The information structure of the gradiometric measurements is identified. Versions of the algorithmic and instrumental implementations of the system are proposed.

Korotaev, Iu. A.

1989-01-01

147

Navigation Systems for Ablation  

PubMed Central

Navigation systems, devices and intra-procedural software are changing the way we practice interventional oncology. Prior to the development of precision navigation tools integrated with imaging systems, thermal ablation of hard-to-image lesions was highly dependent upon operator experience, spatial skills, and estimation of positron emission tomography-avid or arterial-phase targets. Numerous navigation systems for ablation bring the opportunity for standardization and accuracy that extends our ability to use imaging feedback during procedures. Existing systems and techniques are reviewed, and specific clinical applications for ablation are discussed to better define how these novel technologies address specific clinical needs, and fit into clinical practice.

Wood, B. J.; Kruecker, J.; Abi-Jaoudeh, N; Locklin, J.; Levy, E.; Xu, S.; Solbiati, L.; Kapoor, A.; Amalou, H.; Venkatesan, A.

2010-01-01

148

Autonomous satellite navigation with the Global Positioning System  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

149

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

2011-01-01

150

Onboard Navigation Systems Characteristics  

NASA Technical Reports Server (NTRS)

The space shuttle onboard navigation systems characteristics are described. A standard source of equations and numerical data for use in error analyses and mission simulations related to space shuttle development is reported. The sensor characteristics described are used for shuttle onboard navigation performance assessment. The use of complete models in the studies depend on the analyses to be performed, the capabilities of the computer programs, and the availability of computer resources.

1979-01-01

151

Global Navigation Satellite Systems and Inertial Navigation  

Microsoft Academic Search

\\u000a When one would rank the geo-data collection techniques developed the last three decades or so from most significant to least\\u000a significant, positioning and navigation by means of Global Navigation Satellite Systems (GNSS) would head the list. GNSS enables\\u000a obtaining precise positioning and timing information anywhere on land, on sea or in the air, day or night with high precision\\u000a and

Mathias Lemmens

152

Laser Inertial Navigation System  

NASA Technical Reports Server (NTRS)

Acceptable accuracy obtained with short alignment time. Report describes successful helicopter tests of laser inertial navigational equipment. Tests conducted over 3-year period, both in laboratory and flight. Inertial system used as position/velocity/attitude indicator and later also served as part of automatic flight-control system.

Hruby, R. J.; Xenakis, G.; Carestia, R. A.; Bjorkman, W. S.; Schmit, S. F.; Corliss, L. D.

1986-01-01

153

Optimal Kalman Filter Integration of a Global Positioning System Receiver and an LN-94 Inertial Navigation System.  

National Technical Information Service (NTIS)

This research develops and attempts to implement a Kalman filter integration of a Phase III Global Positioning System (GPS) five-channel receiver and an LN-94 Inertial Navigation System (INS). The GPS provides highly accurate position and velocity informa...

J. L. Hirning

1990-01-01

154

Ship Navigation Alarm System.  

National Technical Information Service (NTIS)

This report covers all work done under Contract DAAK02-68-C-0513 by Stewart Warner Electronics (SWE), Chicago, Ill., from 28 June 1968 till 15 July 1969 to develop and test the Ship Navigation Alarm System (SNAS). The prime objective was to determine whet...

H. J. Osinga

1969-01-01

155

Autocalibrating vision guided navigation of unmanned air vehicles via tactical monocular cameras in GPS denied environments  

NASA Astrophysics Data System (ADS)

This thesis presents a novel robotic navigation strategy by using a conventional tactical monocular camera, proving the feasibility of using a monocular camera as the sole proximity sensing, object avoidance, mapping, and path-planning mechanism to fly and navigate small to medium scale unmanned rotary-wing aircraft in an autonomous manner. The range measurement strategy is scalable, self-calibrating, indoor-outdoor capable, and has been biologically inspired by the key adaptive mechanisms for depth perception and pattern recognition found in humans and intelligent animals (particularly bats), designed to assume operations in previously unknown, GPS-denied environments. It proposes novel electronics, aircraft, aircraft systems, systems, and procedures and algorithms that come together to form airborne systems which measure absolute ranges from a monocular camera via passive photometry, mimicking that of a human-pilot like judgement. The research is intended to bridge the gap between practical GPS coverage and precision localization and mapping problem in a small aircraft. In the context of this study, several robotic platforms, airborne and ground alike, have been developed, some of which have been integrated in real-life field trials, for experimental validation. Albeit the emphasis on miniature robotic aircraft this research has been tested and found compatible with tactical vests and helmets, and it can be used to augment the reliability of many other types of proximity sensors.

Celik, Koray

156

Topex orbit determination using GPS tracking system  

Microsoft Academic Search

An extensive simulation study was performed to analyze several aspects of Topex Precise Orbit Determination (POD) using the Global Positioning System (GPS). Since the error modeling is the key to such an experiment, extensive investigation was performed based on real GPS data processing experience to create realistic measurement and dynamic error models for GPS. Double-differenced Topex-GPS phase measurements were evaluated

Hyung Jin Rim

1992-01-01

157

Analysis of Use of Receiver Autonomous Integrity Monitoring (RAIM) in a GPS Wide-Area Augmentation System (WAAS).  

National Technical Information Service (NTIS)

Among different augmentation alternatives for Required Navigation Performance (RNP) use of GPS, a GPS Wide Area Augmentation System (WAAS) could provide precision approach capability over a wide geographic area with a single system. Currently, the FAA is ...

Y. C. Lee

1993-01-01

158

Adaptive calibration of an autonomous underwater vehicle navigation system  

Microsoft Academic Search

There continues to exist the problem of long-term accurate position estimation for autonomous underwater vehicles (AUVs). In current operations, the AUVs positional fix is initially obtained on the surface from a global positioning system (GPS) receiver. The AUV then submerges to perform the desired mission. While submerged, location\\/navigation is performed using, at a minimum, an inertial navigation system (INS). Depending

C. M. De Angelis; J. E. Whitney

2000-01-01

159

GPS-Based Navigation And Orbit Determination for the AMSAT AO-40 Satellite  

NASA Technical Reports Server (NTRS)

The AMSAT OSCAR-40 (AO-40) spacecraft occupies a highly elliptical orbit (HEO) to support amateur radio experiments. An interesting aspect of the mission is the attempted use of GPS for navigation and attitude determination in HEO. Previous experiences with GPS tracking in such orbits have demonstrated the ability to acquire GPS signals, but very little data were produced for navigation and orbit determination studies. The AO-40 spacecraft, flying two Trimble Advanced Navigation Sensor (TANS) Vector GPS receivers for signal reception at apogee and at perigee, is the first to demonstrate autonomous tracking of GPS signals from within a HEO with no interaction from ground controllers. Moreover, over 11 weeks of total operations as of June 2002, the receiver has returned a continuous stream of code phase, Doppler, and carrier phase measurements useful for studying GPS signal characteristics and performing post-processed orbit determination studies in HEO. This paper presents the initial efforts to generate AO-40 navigation solutions from pseudorange data reconstructed from the TANS Vector code phase, as well as to generate a precise orbit solution for the AO-40 spacecraft using a batch filter.

Davis, George; Moreau, Michael; Carpenter, Russell; Bauer, Frank

2002-01-01

160

Navigating the Return Trip from the Moon Using Earth-Based Ground Tracking and GPS  

NASA Technical Reports Server (NTRS)

NASA s Constellation Program is planning a human return to the Moon late in the next decade. From a navigation perspective, one of the most critical phases of a lunar mission is the series of burns performed to leave lunar orbit, insert onto a trans-Earth trajectory, and target a precise re-entry corridor in the Earth s atmosphere. A study was conducted to examine sensitivity of the navigation performance during this phase of the mission to the type and availability of tracking data from Earth-based ground stations, and the sensitivity to key error sources. This study also investigated whether GPS measurements could be used to augment Earth-based tracking data, and how far from the Earth GPS measurements would be useful. The ability to track and utilize weak GPS signals transmitted across the limb of the Earth is highly dependent on the configuration and sensitivity of the GPS receiver being used. For this study three GPS configurations were considered: a "standard" GPS receiver with zero dB antenna gain, a "weak signal" GPS receiver with zero dB antenna gain, and a "weak signal" GPS receiver with an Earth-pointing direction antenna (providing 10 dB additional gain). The analysis indicates that with proper selection and configuration of the GPS receiver on the Orion spacecraft, GPS can potentially improve navigation performance during the critical final phases of flight prior to Earth atmospheric entry interface, and may reduce reliance on two-way range tracking from Earth-based ground stations.

Berry, Kevin; Carpenter, Russell; Moreau, Michael C.; Lee, Taesul; Holt, Gregg N.

2009-01-01

161

Cloud Absorption Radiometer Autonomous Navigation System - CANS  

NASA Technical Reports Server (NTRS)

CAR (cloud absorption radiometer) acquires spatial reference data from host aircraft navigation systems. This poses various problems during CAR data reduction, including navigation data format, accuracy of position data, accuracy of airframe inertial data, and navigation data rate. Incorporating its own navigation system, which included GPS (Global Positioning System), roll axis inertia and rates, and three axis acceleration, CANS expedites data reduction and increases the accuracy of the CAR end data product. CANS provides a self-contained navigation system for the CAR, using inertial reference and GPS positional information. The intent of the software application was to correct the sensor with respect to aircraft roll in real time based upon inputs from a precision navigation sensor. In addition, the navigation information (including GPS position), attitude data, and sensor position details are all streamed to a remote system for recording and later analysis. CANS comprises a commercially available inertial navigation system with integral GPS capability (Attitude Heading Reference System AHRS) integrated into the CAR support structure and data system. The unit is attached to the bottom of the tripod support structure. The related GPS antenna is located on the P-3 radome immediately above the CAR. The AHRS unit provides a RS-232 data stream containing global position and inertial attitude and velocity data to the CAR, which is recorded concurrently with the CAR data. This independence from aircraft navigation input provides for position and inertial state data that accounts for very small changes in aircraft attitude and position, sensed at the CAR location as opposed to aircraft state sensors typically installed close to the aircraft center of gravity. More accurate positional data enables quicker CAR data reduction with better resolution. The CANS software operates in two modes: initialization/calibration and operational. In the initialization/calibration mode, the software aligns the precision navigation sensors and initializes the communications interfaces with the sensor and the remote computing system. It also monitors the navigation data state for quality and ensures that the system maintains the required fidelity for attitude and positional information. In the operational mode, the software runs at 12.5 Hz and gathers the required navigation/attitude data, computes the required sensor correction values, and then commands the sensor to the required roll correction. In this manner, the sensor will stay very near to vertical at all times, greatly improving the resulting collected data and imagery. CANS greatly improves quality of resulting imagery and data collected. In addition, the software component of the system outputs a concisely formatted, high-speed data stream that can be used for further science data processing. This precision, time-stamped data also can benefit other instruments on the same aircraft platform by providing extra information from the mission flight.

Kahle, Duncan; Gatebe, Charles; McCune, Bill; Hellwig, Dustan

2013-01-01

162

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

163

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

164

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

Microsoft Academic Search

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,

Priyanka Aggarwal; Zainab Syed; Naser El-Sheimy

2009-01-01

165

Autonomous Navigation Technology (ANT) System.  

National Technical Information Service (NTIS)

A laboratory evaluation of an Interferometric Landmark Tracker (ILT) for an autonomous spacecraft navigation system was conducted. The system processes ILT, inertial reference unit, and star sensor data in a Kalman filter to provide in-space navigation. S...

R. L. Fritz D. H. Aldrich N. F. Toda

1974-01-01

166

Shuttle Global Positioning (GPS) System design study  

NASA Technical Reports Server (NTRS)

Investigations of certain aspects and problems of the shuttle global positioning system GPS, are presented. Included are: test philosophy and test outline; development of a phase slope specification for the shuttle GPS antenna; an investigation of the shuttle jamming vulnerability; and an expression for the GPS signal to noise density ratio for the thermal protection system.

Nilsen, P.; Huth, G. K.

1980-01-01

167

GPS error modeling and OTF ambiguity resolution for high-accuracy GPS\\/INS integrated system  

Microsoft Academic Search

.   The Center for Mapping at The Ohio State University is currently developing a fully digital Airborne Integrated Mapping System\\u000a (AIMS) for large-scale mapping and other precise positioning applications. AIMS, installed in an aerial platform, incorporates\\u000a state-of-the-art positioning [differential Global Positioning System (GPS) integrated with an Inertial Navigation System (INS)]\\u000a and imaging (Charge-Coupled Device) technologies. The project goal is to

D. A. Grejner-Brzezinska; R. da; C. Toth

1998-01-01

168

Interoperability of satellite-based augmentation systems for aircraft navigation  

Microsoft Academic Search

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

Donghai Dai

2001-01-01

169

A new multi-position calibration method for MEMS inertial navigation systems  

Microsoft Academic Search

The Global Positioning System (GPS) is a worldwide navigation system that requires a clear line of sight to the orbiting satellites. For land vehicle navigation, a clear line of sight cannot be maintained all the time as the vehicle can travel through tunnels, under bridges, forest canopies or within urban canyons. In such situations, the augmentation of GPS with other

Z F Syed; P Aggarwal; C Goodall; X Niu; N El-Sheimy

2007-01-01

170

Cosmic Navigation and Inertial Navigation System  

NASA Astrophysics Data System (ADS)

In this paper, we expose general performance of navigation, compared and opposed to astrodynamics and marine navigation, observing methods for determining the orbit and operating in the Space and on the Earth and, also, pre-satellite and post-satellite era of cosmic navigation.

Samardzija, B.; Segan, S.

2012-12-01

171

GPS/Magnetometer Based Satellite Navigation and Attitude Determination  

NASA Technical Reports Server (NTRS)

In recent years algorithms were developed for orbit, attitude and angular-rate determination of Low Earth Orbiting (LEO) satellites. Those algorithms rely on measurements of magnetometers, which are standard, relatively inexpensive, sensors that are normally installed on every LEO satellite. Although magnetometers alone are sufficient for obtaining the desired information, the convergence of the algorithms to the correct values of the satellite orbital parameters, position, attitude and angular velocity is very slow. The addition of sun sensors reduces the convergence time considerably. However, for many LEO satellites the sun data is not available during portions of the orbit when the spacecraft (SC) is in the earth shadow. It is here where the GPS space vehicles (SV) can provide valuable support. This is clearly demonstrated in the present paper. Although GPS measurements alone can be used to obtain SC position, velocity, attitude and angular-rate, the use of magnetometers improve the results due to the synergistic effect of sensor fusion. Moreover, it is possible to obtain these results with less than three SVs. In this paper we introduce an estimation algorithm, which is a combination of an Extended Kalman Filter (EKF) and a Pseudo Linear Kalman Filter (PSELIKA).

Deutschmann, Julie; Bar-Itzhack, Itzhack; Harman, Rick; Bauer, Frank H. (Technical Monitor)

2001-01-01

172

Extended Kalman filter synthesis for integrated global positioning\\/inertial navigation systems  

Microsoft Academic Search

The integrated global position system (GPS)\\/inertial navigation system (INS) is a cost-effective way of providing an accurate and reliable navigation system for civil and military aviation. These systems also provide low cost solutions to mid-course navigation and guidance of medium- and long-range weapon systems. In this paper, an error model developed earlier is used for GPS\\/INS filter mechanization (F.A. Faruqi,

Farhan A. Faruqi; Kenneth J. Turner

2000-01-01

173

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

National Technical Information Service (NTIS)

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 opti...

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

1997-01-01

174

Ranging error overbounds for navigation integrity of local area augmented GPS  

Microsoft Academic Search

The use of Differential GPS (DGPS) in aviation has been especially attractive in the past decade because of its potential to provide the means for satellite-based aircraft navigation spanning all aspects of flight, from takeoff to touchdown, with low cost and high availability. While this has been an inspiring goal, serious technical obstacles exist, the most difficult of which are

Irfan Sayim

2003-01-01

175

GPS systems to be demonstrated  

NASA Astrophysics Data System (ADS)

Most of us think of the settings of scientific meetings in terms of darkened rooms with slide projectors, or arrays of bulletin boards and video screens with poster papers. One of the most visible sessions at the 1986 AGU Fall Meeting/ASLO Winter Meeting, however, will be a demonstration of the Global Positioning System (GPS) on the lawn and sidewalk area just across from the Civic Auditorium in San Francisco, Calif.Although the demonstration will begin in the wee hours of the morning on Tuesday, December 9 (rain date: Wednesday, December 10), the instruments—at least three different pairs of GPS instruments from different manufacturers—will remain set up for examination during the morning sessions that day. The observations will be reduced with microcomputer software packages in an informal session on Wednesday afternoon, and the results of the measurements and reductions will be presented as part of a poster session on the morning of Thursday, December 11.

Katzoff, Judith A.

176

IMU/GPS System Provides Position and Attitude Data  

NASA Technical Reports Server (NTRS)

A special navigation system is being developed to provide high-quality information on the position and attitude of a moving platform (an aircraft or spacecraft), for use in pointing and stabilization of a hyperspectral remote-sensing system carried aboard the platform. The system also serves to enable synchronization and interpretation of readouts of all onboard sensors. The heart of the system is a commercially available unit, small enough to be held in one hand, that contains an integral combination of an inertial measurement unit (IMU) of the microelectromechanical systems (MEMS) type, Global Positioning System (GPS) receivers, a differential GPS subsystem, and ancillary data-processing subsystems. The system utilizes GPS carrier-phase measurements to generate time data plus highly accurate and continuous data on the position, attitude, rotation, and acceleration of the platform. Relative to prior navigation systems based on IMU and GPS subsystems, this system is smaller, is less expensive, and performs better. Optionally, the system can easily be connected to a laptop computer for demonstration and evaluation. In addition to airborne and spaceborne remote-sensing applications, there are numerous potential terrestrial sensing, measurement, and navigation applications in diverse endeavors that include forestry, environmental monitoring, agriculture, mining, and robotics.

Lin, Ching Fang

2006-01-01

177

Vision enhanced navigation for unmanned systems  

NASA Astrophysics Data System (ADS)

A vision based simultaneous localization and mapping (SLAM) algorithm is evaluated for use on unmanned systems. SLAM is a technique used by a vehicle to build a map of an environment while concurrently keeping track of its location within the map, without a priori knowledge. The work in this thesis is focused on using SLAM as a navigation solution when global positioning system (GPS) service is degraded or temporarily unavailable. Previous work on unmanned systems that lead up to the determination that a better navigation solution than GPS alone is first presented. This previous work includes control of unmanned systems, simulation, and unmanned vehicle hardware testing. The proposed SLAM algorithm follows the work originally developed by Davidson et al. in which they dub their algorithm MonoSLAM [1--4]. A new approach using the Pyramidal Lucas-Kanade feature tracking algorithm from Intel's OpenCV (open computer vision) library is presented as a means of keeping correct landmark correspondences as the vehicle moves through the scene. Though this landmark tracking method is unusable for long term SLAM due to its inability to recognize revisited landmarks, as opposed to the Scale Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF), its computational efficiency makes it a good candidate for short term navigation between GPS position updates. Additional sensor information is then considered by fusing INS and GPS information into the SLAM filter. The SLAM system, in its vision only and vision/IMU form, is tested on a table top, in an open room, and finally in an outdoor environment. For the outdoor environment, a form of the slam algorithm that fuses vision, IMU, and GPS information is tested. The proposed SLAM algorithm, and its several forms, are implemented in C++ using an Extended Kalman Filter (EKF). Experiments utilizing a live video feed from a webcam are performed. The different forms of the filter are compared and conclusions are made on the effectiveness of the SLAM algorithm for use on the current unmanned vehicles in Purdue's Hybrid Systems Lab. Recommendations for future improvements in applying computer vision to unmanned systems are also presented in the final chapter.

Wampler, Brandon Loy

178

Galileo \\/ GPS indoor navigation & positioning for SAR and tracking applications  

Microsoft Academic Search

“INDOOR” is a German research project for providing a combined outdoor\\/indoor navigation capability for location based services of security-sensitive applications (SAR) as well as for important professional logistic or tracking applications, e.g. asset\\/child tracking. The project consortium is built of nine partners from industry, research institutes and universities with IFEN GmbH being the coordinator of the project. The work is

Erwin Löhnert; Wolfgang Bär; Eckart Göhler; Jochen Möllmer

2010-01-01

179

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

180

Inertial Navigation Systems: Prelaunch Alignment  

Microsoft Academic Search

A conventional inertial navigation system navigates by sensing components of the acceleration vector along three mutually perpendicular axes held stable after some initial alignment. This paper discusses the need for initial alignment, followed by a review of the effects of alignment errors on navigation in order to establish the order of accuracies desired. Several alignment techniques are described and compared

Richard H. Parvin

1962-01-01

181

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

182

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

Federal Register 2010, 2011, 2012, 2013

...Navigation Equipment Using the Global Positioning System (GPS) AGENCY: Federal Aviation...Navigation Equipment Using the Global Positioning System (GPS...Navigation Equipment Using the Global Positioning System (GPS) effective October...

2011-10-13

183

Doppler Lidar Sensor for Precision Navigation in GPS-Deprived Environment  

NASA Technical Reports Server (NTRS)

Landing mission concepts that are being developed for exploration of solar system bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe, soft landing at the pre-designated sites. Data from the vehicle's Inertial Measurement Unit will not be sufficient due to significant drift error after extended travel time in space. Therefore, an onboard sensor is required to provide the necessary data for landing in the GPS-deprived environment of space. For this reason, NASA Langley Research Center has been developing an advanced Doppler lidar sensor capable of providing accurate and reliable data suitable for operation in the highly constrained environment of space. The Doppler lidar transmits three laser beams in different directions toward the ground. The signal from each beam provides the platform velocity and range to the ground along the laser line-of-sight (LOS). The six LOS measurements are then combined in order to determine the three components of the vehicle velocity vector, and to accurately measure altitude and attitude angles relative to the local ground. These measurements are used by an autonomous Guidance, Navigation, and Control system to accurately navigate the vehicle from a few kilometers above the ground to the designated location and to execute a gentle touchdown. A prototype version of our lidar sensor has been completed for a closed-loop demonstration onboard a rocket-powered terrestrial free-flyer vehicle.

Amzajerdian, F.; Pierrottet, D. F.; Hines, G. D.; Hines, G. D.; Petway, L. B.; Barnes, B. W.

2013-01-01

184

Doppler lidar sensor for precision navigation in GPS-deprived environment  

NASA Astrophysics Data System (ADS)

Landing mission concepts that are being developed for exploration of solar system bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe, soft landing at the pre-designated sites. Data from the vehicle's Inertial Measurement Unit will not be sufficient due to significant drift error after extended travel time in space. Therefore, an onboard sensor is required to provide the necessary data for landing in the GPS-deprived environment of space. For this reason, NASA Langley Research Center has been developing an advanced Doppler lidar sensor capable of providing accurate and reliable data suitable for operation in the highly constrained environment of space. The Doppler lidar transmits three laser beams in different directions toward the ground. The signal from each beam provides the platform velocity and range to the ground along the laser line-of-sight (LOS). The six LOS measurements are then combined in order to determine the three components of the vehicle velocity vector, and to accurately measure altitude and attitude angles relative to the local ground. These measurements are used by an autonomous Guidance, Navigation, and Control system to accurately navigate the vehicle from a few kilometers above the ground to the designated location and to execute a gentle touchdown. A prototype version of our lidar sensor has been completed for a closed-loop demonstration onboard a rocket-powered terrestrial free-flyer vehicle.

Amzajerdian, F.; Pierrottet, D. F.; Hines, G. D.; Petway, L. B.; Barnes, B. W.

2013-05-01

185

An integrated land navigation system  

Microsoft Academic Search

An exploratory development model of an optimally integrated system for Artic land navigation has been designed, implemented, and tested. This system, called PLANS (Primary Land Arctic Navigation System) was designed and built to be a highly reliable, moderately accurate and moderately priced, nonradiating automatic navigation system for all-weather off-the-road use. It combines several self-contained sensors with two satellite receivers, using

J. C. McMillan

1988-01-01

186

Flight Evaluation of GPS/DGPS Sensor Systems Installed in NAL Do228.  

National Technical Information Service (NTIS)

Navigation systems have been tested with a Dornier 228-200 (Do228), experimental research airplane of National Aerospace Laboratory (NAL) at Sendai airport, Japan. A Clear and Acquisition (C/A) code single channel Global Positioning System (GPS) recerver ...

K. Ishikawa T. Ono M. Murata T. Tsujii H. Mineno S. Matsumoto

1993-01-01

187

Global Positioning Systems (GPS) High Dynamic User Equipment (HDUE). Volume II. Set Description.  

National Technical Information Service (NTIS)

Describes Texas Instruments design of the HDUE set as implemented during Phase I of the GPS program, including system description; HDUE receiver control, Master Control, Navigation and Executive Subsystems; and Hardware System Description. (Author)

1979-01-01

188

Multisensor Data Fusion in Adaptive Astro-Satellite-Inertial Navigation System  

Microsoft Academic Search

This paper presents the fusion algorithm for navigation information from three distinct sources: strapdown inertial navigation system (SINS), GPS receiver and astronavigation system (ANS) i.e. for SINS\\/ANS\\/GPS integrated navigation system in the presence of non- stationary Gaussian noise. Adaptive innovation-based (maximum-likelihood covariance) Kalman filter is used to estimate errors of SINS position, velocity, attitude, accelerometers, gyroscopes and gravitation acceleration to

Leonid A. Fokin

2007-01-01

189

Unaugmented GPS-Based Flight Inspection System  

Microsoft Academic Search

A unaugmented Global Positioning System (GPS)-based flight inspection system (FIS) that performs airborne inspection of the instrument landing system (ILS) is introduced. This novel system relies on a TV positioning system (TVPS) that measures the horizontal position over the runway threshold and a radar altimeter (RA) to determine a reference point that is able to remove the GPS biases. Because

Euiho Kim; Todd Walter; J. David Powell

2010-01-01

190

Operational considerations for use of GPS integrity information in the National Airspace System  

NASA Astrophysics Data System (ADS)

The author discusses the integrity of the GPS (Global Positioning System) as applied to flight operations in the National Airspace System. A generic scenario for failure of navigation signals-in-space is defined. Concern is focused on the state of temporary navigation on notification of a failure, and subsequent recovery to continued radionavigation. Operational considerations are identified to reflect the impact on pilot and air traffic control. A comparison of receiver autonomous and GPS integrity channel monitoring is presented with regard to these considerations. General guidelines are suggested for assuring that GPS navigation equipment properly uses the integrity information to satisfy operational considerations of safety and workload.

Shively, Curtis A.

191

Performance of an AUV navigation system at Arctic latitudes  

Microsoft Academic Search

In October 2001, the Monterey Bay Aquarium Research Institute (MBARI) operated an autonomous underwater vehicle (AUV) in the Arctic at latitudes exceeding 80°. The navigation instruments consisted of a ring-laser gyro inertial navigation system (INS) coupled with a DVL and GPS, a separate fiber-optic-based gyro-compass, and a traditional flux-gate AHRS system. The instruments were tested on deck, in open water,

Rob McEwen; Hans Thomas; Don Weber; Frank Psota

2005-01-01

192

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

193

Combining Cricket System and Inertial Navigation for Indoor Human Tracking  

Microsoft Academic Search

We present a system-level approach to localizing and tracking users on a basis of different sources of location information. We have applied a combination of the Cricket sys- tem and inertial navigation sensors to improve the coverage and accuracy of our framework when used in indoor conditions. The system can be applied outdoors as well using, for example, GPS as

Michael Popa; Junaid Ansari; Janne Riihijärvi; Petri Mähönen

2008-01-01

194

Ionosphere tomography with data from satellite reception of Global Navigation Satellite System signals and ground reception of Navy Navigation Satellite System signals  

Microsoft Academic Search

GPS\\/MET, a multichannel Global Positioning System (GPS) receiver onboard the small research satellite MicroLab 1, is the first example of a research tool of great importance for ionospheric research. In the near future, other satellites with GPS\\/GLONASS (Global Navigation Satellite System (also GNSS)) receivers will be launched. Their main purpose is lower atmosphere research, but because of the necessity to

R. Leitinger; H.-P. Ladreiter; G. Kirchengast

1997-01-01

195

Application of GPS systems on a mobile robot  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to describe the use of Global Positioning Systems (GPS) as geographic information and navigational system for a ground based mobile robot. Several low cost wireless systems are now available for a variety of innovative automobile applications including location, messaging and tracking and security. Experiments were conducted with a test bed mobile robot, Bearcat II, for point-to-point motion using a Motorola GPS in June 2001. The Motorola M12 Oncore GPS system is connected to the Bearcat II main control computer through a RS232 interface. A mapping program is used to define a desired route. Then GPS information may be displayed for verification. However, the GPS information is also used to update the control points of the mobile robot using a reinforcement learning method. Local position updates are also used when found in the environment. The significance of the method is in extending the use of GPS to local vehicle control that requires more resolution that is available from the raw data using the adaptive control method.

Cao, Peter; Saxena, Mayank; Tedder, Maurice; Mischalske, Steve; Hall, Ernest L.

2001-10-01

196

Integrated Navigation System for the Second Generation Reusable Launch Vehicle  

NASA Technical Reports Server (NTRS)

An array of components in a laboratory at NASA's Marshall Space Flight Center (MSFC) is being tested by the Flight Mechanics Office to develop an integrated navigation system for the second generation reusable launch vehicle. The laboratory is testing Global Positioning System (GPS) components, a satellite-based location and navigation system, and Inertial Navigation System (INS) components, sensors on a vehicle that determine angular velocity and linear acceleration at various points. The GPS and INS components work together to provide a space vehicle with guidance and navigation, like the push of the OnStar button in your car assists you with directions to a specific address. The integration will enable the vehicle operating system to track where the vehicle is in space and define its trajectory. The use of INS components for navigation is not new to space technology. The Space Shuttle currently uses them. However, the Space Launch Initiative is expanding the technology to integrate GPS and INS components to allow the vehicle to better define its position and more accurately determine vehicle acceleration and velocity. This advanced technology will lower operational costs and enhance the safety of reusable launch vehicles by providing a more comprehensive navigation system with greater capabilities. In this photograph, Dr. Jason Chuang of MSFC inspects an INS component in the laboratory.

2002-01-01

197

Differential wheel speed sensor integration with GPS/INS for land vehicle navigation  

NASA Astrophysics Data System (ADS)

This paper develops an approach for the integration of GPS, inertial measurements from accelerometers and gyros, and differential wheel speed sensors for land vehicle navigation. Incorporating differential wheel speed sensor information into land vehicle navigation provides a solution for eliminating large errors caused by vehicle roll and pitch while also reducing errors from sideslip. Extended Kalman and Unscented Filtering algorithms are designed with a six degree-of-freedom model. In order to incorporate differential wheel speed information properly, the effective wheel radius must also be estimated as part of the overall estimation approach. Simulation results show the performance of the filters for cases of GPS/INS with and without the differential wheel speed sensor.

Hazlett, Andrew C.

198

Navigational and Environmental Measurement System (NEMS)  

NASA Technical Reports Server (NTRS)

The NEMS concept and design were initiated from the need to measure and record positional and environmental information during aircraft flights of developmental science research instrumentation. The unit was designed as a stand-alone system which could serve the needs of instruments whose developmental nature did not justify the cost and complexity of including these measurements within the instrument data system. Initially, the system was comprised of a Loran-C receiver and a portable IBM compatible computer recording position and time. Later, the system was interfaced with the Wallops aircraft inertial navigation system (INS), and various other sensors were supplied and shared by the Goddard science users. Real-time position mapping on video monitors was added for investigator's use and information. In 1987, the use of a Global Positioning System (GPS) receiver was included in some missions. A total configuration of the system and the various sensors which can be incorporated are shown.

Clem, T. D.

1988-01-01

199

Applicable Tracking Data Arcs for NORAD TLE Orbit Determination of the KOMPSAT-1 Satellite Using GPS Navigation Solutions  

NASA Astrophysics Data System (ADS)

NORAD Two Line Element (TLE) is very useful to simplify the ground station antenna pointing and mission operations. When a satellite operations facility has the capability to determine NORAD type TLE which is independent of NORAD, it is important to analyze the applicable tracking data arcs for obtaining the best possible orbit. The applicable tracking data arcs for NORAD independent TLE orbit determination of the KOMPSAT-1 using GPS navigation solutions was analyzed for the best possible orbit determination and propagation results. Data spans of the GPS navi gation solutions from 1 day to 5 days were used for TLE orbit determination and the results were used as initial orbit for SGP4 orbit propagation. The operational orbit determination results using KOMPSAT-1 Mission Analysis and Planning System (MAPS) were used as references for the comparisons. The best-matched orbit determination was obtained when 3 days of GPS navigation solutions were used. The resulting 4 days of orbit propagation results were within 2 km of the KOMPSAT-1 MAPS results.

Lee, Byoung-Sun

2005-09-01

200

GPS and Remote Sensing for Emergency Vehicle Navigation and Communication  

Microsoft Academic Search

Organizations and individuals have been facing disasters globally and locally since hundreds of years. Increasing number of natural disasters has demonstrated the paramount importance of the natural hazards subject for the protection of environment and the citizens. Now more than ever, designing an efficient traffic system, moving vast amounts of helping goods quickly and safely across great distances is one

Farah Mahmood; Azzam ul Asar; Adnan Mahmood

2006-01-01

201

Real Time Gps Dynamic-Positioning Approaches to Mobile Robot Navigation  

Microsoft Academic Search

Recent siwcant advances in the Global Positioning System (GPS) have contributed to making real time kinematic or dynam~c process for decimetre to centimetre level positioning more reliable and ready for the production-use. As a result of research and development efforts in this area at QUT, a robust real time ciynam~c (RTD) or kinematic (RTK) GPS positioning software system has been

Yanming Feng; Kurt Kubik

1996-01-01

202

A closed loop GPS-based orbit trim system for Gravity Probe B  

Microsoft Academic Search

An onboard closed loop navigation and control system capable of executing extremely precise orbit maneuvers is described. In particular, a system to adjust the orbit of the Gravity Probe B (GP-B) spacecraft is presented. This onboard system relies on the Global Positioning System (GPS) to provide navigation information directly to the vehicle, thus alleviating the need for ground support. GP-B

Penina Axelrad

1991-01-01

203

Using APEX to Model Anticipated Human Error: Analysis of a GPS Navigational Aid  

NASA Technical Reports Server (NTRS)

The interface development process can be dramatically improved by predicting design facilitated human error at an early stage in the design process. The approach we advocate is to SIMULATE the behavior of a human agent carrying out tasks with a well-specified user interface, ANALYZE the simulation for instances of human error, and then REFINE the interface or protocol to minimize predicted error. This approach, incorporated into the APEX modeling architecture, differs from past approaches to human simulation in Its emphasis on error rather than e.g. learning rate or speed of response. The APEX model consists of two major components: (1) a powerful action selection component capable of simulating behavior in complex, multiple-task environments; and (2) a resource architecture which constrains cognitive, perceptual, and motor capabilities to within empirically demonstrated limits. The model mimics human errors arising from interactions between limited human resources and elements of the computer interface whose design falls to anticipate those limits. We analyze the design of a hand-held Global Positioning System (GPS) device used for radical and navigational decisions in small yacht recalls. The analysis demonstrates how human system modeling can be an effective design aid, helping to accelerate the process of refining a product (or procedure).

VanSelst, Mark; Freed, Michael; Shefto, Michael (Technical Monitor)

1997-01-01

204

Receiver autonomous integrity monitoring (RAIM) capability for sole-means GPS navigation in the oceanic phase of flight  

Microsoft Academic Search

Receiver autonomous integrity monitoring (RAIM), a GPS integrity monitoring scheme that uses redundant ranging signals to detect a satellite malfunction that results in a large range error, involves two functions: detection of the presence of a malfunctioning satellite and identification of which satellite (or satellites) is malfunctioning. An analysis is presented of GPS RAIM capability for sole-means navigation in the

Young C. Lee

1992-01-01

205

Shuttle Global Positioning System (GPS) system design study  

NASA Technical Reports Server (NTRS)

The various integration problems in the Shuttle GPS system were investigated. The analysis of the Shuttle GPS link was studied. A preamplifier was designed since the Shuttle GPS antennas must be located remotely from the receiver. Several GPS receiver architecture trade-offs were discussed. The Shuttle RF harmonics and intermode that fall within the GPS receiver bandwidth were analyzed. The GPS PN code acquisition was examined. Since the receiver clock strongly affects both GPS carrier and code acquisition performance, a clock model was developed.

Nilsen, P. W.

1979-01-01

206

Delay/Doppler-Mapping GPS-Reflection Remote-Sensing System  

NASA Technical Reports Server (NTRS)

A radio receiver system that features enhanced capabilities for remote sensing by use of reflected Global Positioning System (GPS) signals has been developed. This system was designed primarily for ocean altimetry, but can also be used for scatterometry and bistatic synthetic-aperture radar imaging. Moreover, it could readily be adapted to utilize navigation-satellite systems other than the GPS, including the Russian Global Navigation Satellite System GLONASS) and the proposed European Galileo system. This remote-sensing system offers both advantages and disadvantages over traditional radar altimeters: One advantage of GPS-reflection systems is that they cost less because there is no need to transmit signals. Another advantage is that there are more simultaneous measurement opportunities - one for each GPS satellite in view. The primary disadvantage is that in comparison with radar signals, GPS signals are weaker, necessitating larger antennas and/or longer observations. This GPS-reflection remote-sensing system was tested in aircraft and made to record and process both (1) signals coming directly from GPS satellites by means of an upward-looking antenna and (2) GPS signals reflected from the ground by means of a downward-looking antenna. In addition to performing conventional GPS processing, the system records raw signals for postprocessing as required.

Lowe, Stephen; Kroger, Peter; Franklin, Garth; LeBrecque, John; Lerma, Jesse; Lough, Michael; Marcin, Martin; Muellerschoen, Ronald; Spitzmesser, Donovan; Young, Lawrence

2003-01-01

207

Differential GPS\\/inertial navigation approach\\/landing flight test results  

Microsoft Academic Search

In November 1990, a differential GPS\\/inertial flight test was conducted to acquire a system performance database and demonstrate automatic landing using an integrated differential GPS\\/INS with barometric and radar altimeters. Flight test results obtained from postflight data analysis are presented. These results include characteristics of DGPS\\/inertial error, using a laser tracker as a reference. In addition, data are provided on

S. Snyder; B. Schipper; L. Vallot; N. Parker; C. Spitzer

1992-01-01

208

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...

209

Integrated communications and optical navigation system  

NASA Astrophysics Data System (ADS)

The Integrated Communications and Optical Navigation System (ICONS) is a flexible navigation system for spacecraft that does not require global positioning system (GPS) measurements. The navigation solution is computed using an Unscented Kalman Filter (UKF) that can accept any combination of range, range-rate, planet chord width, landmark, and angle measurements using any celestial object. Both absolute and relative orbit determination is supported. The UKF employs a full nonlinear dynamical model of the orbit including gravity models and disturbance models. The ICONS package also includes attitude determination algorithms using the UKF algorithm with the Inertial Measurement Unit (IMU). The IMU is used as the dynamical base for the attitude determination algorithms. This makes the sensor a more capable plug-in replacement for a star tracker, thus reducing the integration and test cost of adding this sensor to a spacecraft. Recent additions include an integrated optical communications system which adds communications, and integrated range and range rate measurement and timing. The paper includes test results from trajectories based on the NASA New Horizons spacecraft.

Mueller, J.; Pajer, G.; Paluszek, M.

2013-12-01

210

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

211

Simplified Orbit Determination Algorithm for Low Earth Orbit Satellites Using Spaceborne Gps Navigation Sensor  

NASA Astrophysics Data System (ADS)

In this paper, the main work is focused on designing and simplifying the orbit determination algorithm which will be used for Low Earth Orbit (LEO) navigation. The various data processing algorithms, state estimation algorithms and modeling forces were studied in detail, and simplified algorithm is selected to reduce hardware burden and computational cost. This is done by using raw navigation solution provided by GPS Navigation sensor. A fixed step-size Runge-Kutta 4th order numerical integration method is selected for orbit propagation. Both, the least square and Extended Kalman Filter (EKF) orbit estimation algorithms are developed and the results of the same are compared with each other. EKF algorithm converges faster than least square algorithm. EKF algorithm satisfies the criterions of low computation burden which is required for autonomous orbit determination. Simple static force models also feasible to reduce the hardware burden and computational cost.

Tukaram Aghav, Sandip; Achyut Gangal, Shashikala

2014-06-01

212

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.

213

Analysis of Spaceborne GPS Systems  

NASA Technical Reports Server (NTRS)

A reasonable amount of literature can be found on the general topic of GPS receiving antennas, but very little has been published on spaceborne GPS receiving antennas. This very new topic seems to be so far more of interest for the industrial world than for the academic community. For satellite applications, microstrip antennas are usually preferred over other types of antennas mainly because of their non-electrical characteristics, such as small size, relatively lightweight, shape, possibility of integration with microwave integrated circuits, and relatively low costs. Careful design of patch antennas could meet all the requirements (electrical and non-electrical) of GPS receiving antenna to be mounted on a tethered satellite.

Cosmo, Mario L.; Davis, James L.; Elosegui, Pedro; Hill, Michael; ScireScapuzzo, Francesca

1998-01-01

214

A Constructive and Autonomous Integration Scheme of Low-Cost GPS\\/MEMS IMU for Land Vehicular Navigation Applications  

Microsoft Academic Search

The integration of GPS and INS provides a system that has superior performance in comparison with either a GPS or an INS stand-alone systems. Most integrated GPS\\/INS positioning systems have been implemented using Kalman Filter (KF) technique. Although of being widely used, KF has some drawbacks related to computation load, immunity to noise effects and observability. In addition, KF only

Kai-Wei Chiang; Semah Nassar; Naser El-Sheimy

2006-01-01

215

The Performance Analysis of a 3d Map Embedded Ins/gps Fusion Algorithm for Seamless Vehicular Navigation in Elevated Highway Environments  

NASA Astrophysics Data System (ADS)

In this study, a 3D Map Matching (3D MM) algorithm is embedded to current INS/GPS fusion algorithm for enhancing the sustainability and accuracy of INS/GPS integration systems, especially the height component. In addition, this study propose an effective solutions to the limitation of current commercial vehicular navigation systems where they fail to distinguish whether the vehicle is moving on the elevated highway or the road under it because those systems don't have sufficient height resolution. To validate the performance of proposed 3D MM embedded INS/GPS integration algorithms, in the test area, two scenarios were considered, paths under the freeways and streets between tall buildings, where the GPS signal is obstacle or interfered easily. The test platform was mounted on the top of a land vehicle and also systems in the vehicle. The IMUs applied includes SPAN-LCI (0.1 deg/hr gyro bias) from NovAtel, which was used as the reference system, and two MEMS IMUs with different specifications for verifying the performance of proposed algorithm. The preliminary results indicate the proposed algorithms are able to improve the accuracy of positional components in GPS denied environments significantly with the use of INS/GPS integrated systems in SPP mode.

Lee, Y. H.; Chiang, K. W.

2012-07-01

216

Non-linear mathematical model for integrated global positioning\\/inertial navigation systems  

Microsoft Academic Search

In recent years there has been a major upsurge of interest in the integrated global positioning system (GPS)\\/inertial navigation system (INS) as a cost-effective way of providing accurate and reliable navigation aid for civil and military vehicles (ships, aircrafts, land vehicles). In this paper an error model is developed which can be used for GPS\\/INS filter mechanization. It is shown

Farhan A. Faruqi

2000-01-01

217

Combined Global Navigation Satellite Systems in the Space Service Volume  

NASA Technical Reports Server (NTRS)

Besides providing position, velocity, and timing (PVT) for terrestrial users, the Global Positioning System (GPS) is also being used to provide PVT information for earth orbiting satellites. In 2006, F. H. Bauer, et. al., defined the Space Service Volume in the paper GPS in the Space Service Volume , presented at ION s 19th international Technical Meeting of the Satellite Division, and looked at GPS coverage for orbiting satellites. With GLONASS already operational, and the first satellites of the Galileo and Beidou/COMPASS constellations already in orbit, it is time to look at the use of the new Global Navigation Satellite Systems (GNSS) coming into service to provide PVT information for earth orbiting satellites. This presentation extends GPS in the Space Service Volume by examining the coverage capability of combinations of the new constellations with GPS GPS was first explored as a system for refining the position, velocity, and timing of other spacecraft equipped with GPS receivers in the early eighties. Because of this, a new GPS utility developed beyond the original purpose of providing position, velocity, and timing services for land, maritime, and aerial applications. GPS signals are now received and processed by spacecraft both above and below the GPS constellation, including signals that spill over the limb of the earth. Support of GPS space applications is now part of the system plan for GPS, and support of the Space Service Volume by other GNSS providers has been proposed to the UN International Committee on GNSS (ICG). GPS has been demonstrated to provide decimeter level position accuracy in real-time for satellites in low Earth orbit (centimeter level in non-real-time applications). GPS has been proven useful for satellites in geosynchronous orbit, and also for satellites in highly elliptical orbits. Depending on how many satellites are in view, one can keep time locked to the GNSS standard, and through that to Universal Time as long as at least one satellite is in view (the longest duration with no satellites in view is important in determining the maximum clock drift from GNSS time). Instantaneous position requires four satellites in view, but because orbital motion is predictable, it is possible to build up knowledge of the orbital position gradually through time without a need for constant four satellite coverage. However, it is desirable to have four satellite coverage when performing satellite maneuvers, since there can be significant changes in velocity, leading to large changes in orbit parameter, causing substantial divergence in position over time. The Space Service Volume has been defined as the volume between three thousand km altitude and geosynchronous altitude, and can be divided into medium orbit services between three thousand km altitude and eight thousand km altitude, and high orbit services above eight thousand km. The Terrestrial Service Volume includes the Earth s surface, the atmosphere, and space below the altitude of three thousand km. The Terrestrial Service Volume is the volume within which the GNSS systems will have very similar performance to the Earth surface, and satellites need only use the signals specified to provide terrestrial performance. Above three thousand km the use of signals passing by the Earth s limb becomes important, so it is desirable to have additional information on signal strength, phase delay, and group delay covering wider beam angles than are needed for terrestrial service (and which can be obtained by monitoring GNSS signals from the Earth s surface). This presentation will look at each of the new GNSS constellations in combination with GPS (GLONASS with GPS, Galileo with GPS, Beidou/COMPASS with GPS), and also at the combination of all four GNSS systems. The presentation will largely follow the format of GPS in the Space Service Volume , presenting data on the availability of one, two, three, or four of the various combinations of GNSS constellation satelles at approximately two thousand grid points evenly spaced and fixed in longitude and latitude, t

Force, Dale A.; Miller, James J.

2013-01-01

218

14 CFR Special Federal Aviation... - Special Operating Rules for the Conduct of Instrument Flight Rules (IFR) Area Navigation (RNAV...  

Code of Federal Regulations, 2013 CFR

...Components of the GNSS include GPS, the Global Orbiting Navigation Satellite System, and WAAS satellites. Global Positioning System (GPS). GPS is a satellite-based radio navigational, positioning, and time transfer system....

2013-01-01

219

14 CFR Special Federal Aviation... - Special Operating Rules for the Conduct of Instrument Flight Rules (IFR) Area Navigation (RNAV...  

Code of Federal Regulations, 2012 CFR

...Components of the GNSS include GPS, the Global Orbiting Navigation Satellite System, and WAAS satellites. Global Positioning System (GPS). GPS is a satellite-based radio navigational, positioning, and time transfer system....

2012-01-01

220

14 CFR Special Federal Aviation... - Special Operating Rules for the Conduct of Instrument Flight Rules (IFR) Area Navigation (RNAV...  

Code of Federal Regulations, 2011 CFR

...Components of the GNSS include GPS, the Global Orbiting Navigation Satellite System, and WAAS satellites. Global Positioning System (GPS). GPS is a satellite-based radio navigational, positioning, and time transfer system....

2011-01-01

221

Differential GPS/inertial navigation approach/landing flight test results  

NASA Technical Reports Server (NTRS)

Results of a joint Honeywell/NASA-Langley differential GPS/inertial flight test conducted in November 1990 are discussed focusing on postflight data analysis. The test was aimed at acquiring a system performance database and demonstrating automatic landing based on an integrated differential GPS/INS with barometric and radar altimeters. Particular attention is given to characteristics of DGPS/inertial error and the magnitude of the differential corrections and vertical channel performance with and without altimeter augmentation. It is shown that DGPS/inertial integrated with a radar altimeter is capable of providing a precision approach and autoland guidance of manned return space vehicles within the Space Shuttle accuracy requirements.

Snyder, Scott; Schipper, Brian; Vallot, Larry; Parker, Nigel; Spitzer, Cary

1992-01-01

222

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

223

On-line smoothing for an integrated navigation system with low-cost MEMS inertial sensors.  

PubMed

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. PMID:23443403

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

2012-01-01

224

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

225

Orion Absolute Navigation System Progress and Challenges  

NASA Technical Reports Server (NTRS)

The Orion spacecraft is being designed as NASA's next-generation exploration vehicle for crewed missions beyond Low-Earth Orbit. The navigation system for the Orion spacecraft is being designed in a Multi-Organizational Design Environment (MODE) team including contractor and NASA personnel. The system uses an Extended Kalman Filter to process measurements and determine the state. The design of the navigation system has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudorange and deltarange, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, pad alignment, cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.

Holt, Greg N.; D'Souza, Christopher

2011-01-01

226

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.

227

Position Error Correction for an Autonomous Underwater Vehicle Inertial Navigation System (INS) Using a Particle Filter  

Microsoft Academic Search

This paper presents comprehensive testing and analysis of a particle filter (PF) framework for real-time terrain navigation on an autonomous underwater vehicle (AUV). The goal is to obtain georeferenced localization for an AUV navigation system using reference bathymetry maps and bathymetric measurements in lieu of Global Positioning System (GPS) updates or acoustic localization methods such as long baseline (LBL). The

Glenn T. Donovan

2012-01-01

228

Tight coupling of GPS, laser scanner, and inertial measurements for navigation in urban environments  

Microsoft Academic Search

Many applications can be envisioned for accurate, robust, and reliable navigation solution in challenging urban environments. Examples of existing and prospective applications include, but are not limited to, navigation, guidance, and control of autonomous vehicles (including both ground and aerial vehicles) for urban surveillance and reconnaissance; collection of geographical information system (GIS) data in cities; monitoring of urban infrastructure for

Andrey Soloviev

2008-01-01

229

Research of Hybrid Positioning Based Vehicle Interactive Navigation System  

Microsoft Academic Search

Safety is one of main goals of VANET (Vehicular ad hoc Network). In Vehicle Interactive Navigation System, according to vehicle-to-vehicle (V2V) communications vehicle can share its own location within the lane and other information (speed, velocity, acceleration) to the neighboring vehicles so that it allows vehicles to coordinate maneuvers for safety goal such as collision avoidance. Traditionally, GPS is employed

Mingke Fang; Lei Li; Wei Huang

2010-01-01

230

Testing Rtk GPS System In Urban Areas  

NASA Astrophysics Data System (ADS)

RTK GPS is provided with cm accuracy and real time surveying system. For providing this conditions, the reference is necessary for high accuracy position. Because this sta- tion is transmitted the corrections to the other receivers. At the some time this system is required common satellites on the receiver to compute integer ambiguity solution. In addition to the conditions, the data transmission device's range is very important. Although RTK GPS technique has a lot of advantages, many problems meet in prac- tice. One of the most important problem in RTK system, which is very useful and reliable in the rural areas, uses in the urban areas. We search this article, how influence RTK GPS applications on satellite numbers, multipath, data transmission device's range capability and etc. in the urban areas.

Pirti, A.; Ata, E.

231

Miniaturized GPS/MEMS IMU integrated board  

NASA Technical Reports Server (NTRS)

This invention documents the efforts on the research and development of a miniaturized GPS/MEMS IMU integrated navigation system. A miniaturized GPS/MEMS IMU integrated navigation system is presented; Laser Dynamic Range Imager (LDRI) based alignment algorithm for space applications is discussed. Two navigation cameras are also included to measure the range and range rate which can be integrated into the GPS/MEMS IMU system to enhance the navigation solution.

Lin, Ching-Fang (Inventor)

2012-01-01

232

Tightly Coupled Inertial Navigation System/Global Positioning System (TCMIG)  

NASA Technical Reports Server (NTRS)

Many NASA applications planned for execution later this decade are seeking high performance, miniaturized, low power Inertial Management Units (IMU). Much research has gone into Micro-Electro-Mechanical System (MEMS) over the past decade as a solution to these needs. While MEMS devices have proven to provide high accuracy acceleration measurements, they have not yet proven to have the accuracy required by many NASA missions in rotational measurements. Therefore, a new solution has been formulated integrating the best of all IMU technologies to address these mid-term needs in the form of a Tightly Coupled Micro Inertial Navigation System (INS)/Global Positioning System (GPS) (TCMIG). The TCMIG consists of an INS and a GPS tightly coupled by a Kalman filter executing on an embedded Field Programmable Gate Array (FPGA) processor. The INS consists of a highly integrated Interferometric Fiber Optic Gyroscope (IFOG) and a MEMS accelerometer. The IFOG utilizes a tightly wound fiber coil to reduce volume and the high level of integration and advanced optical components to reduce power. The MEMS accelerometer utilizes a newly developed deep etch process to increase the proof mass and yield a highly accurate accelerometer. The GPS receiver consists of a low power miniaturized version of the Blackjack receiver. Such an IMU configuration is ideal to meet the mid-term needs of the NASA Science Enterprises and the new launch vehicles being developed for the Space Launch Initiative (SLI).

Watson, Michael D.; Jackson, Kurt (Technical Monitor)

2002-01-01

233

Design and Analysis of a Navigation System Using the Federated Filter.  

National Technical Information Service (NTIS)

The purpose of this paper was to design and analyse a federated filter design, to be used for retrofit of an Embedded GPS/INS (EGI) navigation unit into an existing Kalman filter-based air navigation system. A design was selected and simulations were cond...

S. J. Delory

1995-01-01

234

Signal quality monitoring for GPS augmentation systems  

NASA Astrophysics Data System (ADS)

Civilian applications of the Global Positioning System have grown rapidly over the past decade. One of the most significant examples is guidance for aviation. In conjunction with specially designed equipment on the ground, GPS can provide precision approach and landing capability for aircraft. As with other safety-critical aviation applications, GPS-based landing systems must meet stringent accuracy, safety, and availability requirements set by the Federal Aviation Administration. Currently, compliance with FAA requirements is ensured by a host of monitors including the Signal Quality Monitor, a module specifically tasked with continuously observing raw GPS signals for interference and distortion. This dissertation focuses on several theoretical and practical aspects of SQM design. The discussion begins with in-depth analysis of the seminal event in SQM, a significant anomaly on GPS space vehicle 19 initially observed in 1993. At the time, a tenfold increase in vertical position error was reported when this satellite was in view. Little consensus was initially reached about the exact origin, nature, or magnitude of the distortion; this section considers these effects in detail. The analysis is then extended to compute a rigorous upper bound for differential error. Starting with the architecture of a basic landing system, a theoretical worst-case is derived that maximizes user error while defying detection by the ground station. A simplified distortion model, adopted by the International Civil Aviation Organization in response to the worst-case analysis, is also described. The discussion then describes the design and construction of an arbitrary GPS generator. Essential features include architecture, shielding, independent signal and noise levels, and fast switching between two input channels. Two example applications are presented to illustrate the instrument's utility. A theoretical analysis of the ICAO model is validated by measuring the spectra of generated waveforms. Transient responses of a multicorrelator GPS receiver to several distorted waveforms are also presented. The final section presents the first detailed characterization of healthy GPS satellite performance in the context of the ICAO model. Minor signal distortions on healthy satellites do not generally threaten operational safety, but must be taken into account when designing an SQM to meet stringent FAA performance requirements.

Mitelman, Alexander Michael

235

Innovative use of global navigation satellite systems for flight inspection  

NASA Astrophysics Data System (ADS)

The International Civil Aviation Organization (ICAO) mandates flight inspection in every country to provide safety during flight operations. Among many criteria of flight inspection, airborne inspection of Instrument Landing Systems (ILS) is very important because the ILS is the primary landing guidance system worldwide. During flight inspection of the ILS, accuracy in ILS landing guidance is checked by using a Flight Inspection System (FIS). Therefore, a flight inspection system must have high accuracy in its positioning capability to detect any deviation so that accurate guidance of the ILS can be maintained. Currently, there are two Automated Flight Inspection Systems (AFIS). One is called Inertial-based AFIS, and the other one is called Differential GPS-based (DGPS-based) AFIS. The Inertial-based AFIS enables efficient flight inspection procedures, but its drawback is high cost because it requires a navigation-grade Inertial Navigation System (INS). On the other hand, the DGPS-based AFIS has relatively low cost, but flight inspection procedures require landing and setting up a reference receiver. Most countries use either one of the systems based on their own preferences. There are around 1200 ILS in the U.S., and each ILS must be inspected every 6 to 9 months. Therefore, it is important to manage the airborne inspection of the ILS in a very efficient manner. For this reason, the Federal Aviation Administration (FAA) mainly uses the Inertial-based AFIS, which has better efficiency than the DGPS-based AFIS in spite of its high cost. Obviously, the FAA spends tremendous resources on flight inspection. This thesis investigates the value of GPS and the FAA's augmentation to GPS for civil aviation called the Wide Area Augmentation System (or WAAS) for flight inspection. Because standard GPS or WAAS position outputs cannot meet the required accuracy for flight inspection, in this thesis, various algorithms are developed to improve the positioning ability of Flight Inspection Systems (FIS) by using GPS and WAAS in novel manners. The algorithms include Adaptive Carrier Smoothing (ACS), optimizing WAAS accuracy and stability, and reference point-based precise relative positioning for real-time and near-real-time applications. The developed systems are WAAS-aided FIS, WAAS-based FIS, and stand-alone GPS-based FIS. These systems offer both high efficiency and low cost, and they have different advantages over one another in terms of accuracy, integrity, and worldwide availability. The performance of each system is tested with experimental flight test data and shown to have accuracy that is sufficient for flight inspection and superior to the current Inertial-based AFIS.

Kim, Eui-Ho

236

The MARCOR GPS mobile data system  

NASA Technical Reports Server (NTRS)

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

1991-01-01

237

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

238

Model of Global Positioning System (GPS) Master Control Station (MCS) Operations.  

National Technical Information Service (NTIS)

The United States Air Force's Navstar Global Positioning System (GPS) provides high-accuracy space-based navigation and time distribution to suitably-equipped military and civilian users. The system consists of earth-orbiting satellites and a world-wide n...

D. N. Koster

1992-01-01

239

Overview of Omega Radio Navigation System.  

National Technical Information Service (NTIS)

Omega is a very low frequency (VLF) navigation system using frequencies allocated for radio navigation in the band between 10 KHz and 14 KHz. Such a low frequency band enables Omega navigation system to achieve the long operating ranges required for globa...

D. F. Liang

1995-01-01

240

A GPS-Based Online Control and Alarm System  

Microsoft Academic Search

  A global positioning system (GPS)-based online control and alarm system (GOCA) for monitoring of three-dimensional movements\\u000a has been developed at the Karlsruhe University of Technology. The GOCA hardware consists of an array of GPS sensors and communication\\u000a units to be placed in the monitoring area. The hardware-dependent control software communicates with the GPS sensors and provides\\u000a the GPS baseline data

Simone Kälber; Reiner Jäger; Rainer Schwäble

2000-01-01

241

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

242

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

243

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

244

Topex orbit determination using GPS tracking system  

NASA Astrophysics Data System (ADS)

An extensive simulation study was performed to analyze several aspects of Topex Precise Orbit Determination (POD) using the Global Positioning System (GPS). Since the error modeling is the key to such an experiment, extensive investigation was performed based on real GPS data processing experience to create realistic measurement and dynamic error models for GPS. Double-differenced Topex-GPS phase measurements were evaluated in relation to improving the Earth geopotential model, which is the dominant error source for Topex POD. The effect of model errors on the Topex orbit and gravity recovery accuracies was evaluated. Long arc and short arc gravity solutions were compared to understand the effect of the model errors in using the long arc and the short arc solutions for the gravity recovery. Limiting factors for the long arc and the short arc gravity recovery were identified. The effect of ambiguity parameters on the gravity recovery was analyzed. Since the number of ambiguity parameters are quite large, an algorithm was developed to handle the ambiguity parameters more efficiently. Subarc parameters and empirical parameters were tested to find an optimal set of parameters to be estimated for the gravity recovery. Several gravity models were obtained by combining Topex-GPS information with a nominal geopotential information. These combined gravity models were evaluated by the statistical comparison of the recovered geopotential model parameters and by the Topex orbit analysis. Significant improvement in the nominal geopotential model, especially for the low degree harmonics, was achieved. More than a factor of three improvement in Topex orbit accuracy was demonstrated using the recovered gravity model. Analysis associated with predicted Topex radial orbit errors using the solution covariance indicates error estimates for the orbit accuracy is realistic.

Rim, Hyung Jin

245

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) [Idaho Falls, ID; Few, Douglas A. (Idaho Falls, ID) [Idaho Falls, ID

2009-09-08

246

Airborne Antenna System for Minimum-Cycle-Slip GPS Reception  

NASA Technical Reports Server (NTRS)

A system that includes a Global Positioning System (GPS) antenna and associated apparatus for keeping the antenna aimed upward has been developed for use aboard a remote-sensing-survey airplane. The purpose served by the system is to enable minimum- cycle-slip reception of GPS signals used in precise computation of the trajectory of the airplane, without having to restrict the airplane to maneuvers that increase the flight time needed to perform a survey. Cycle slip signifies loss of continuous track of the phase of a signal. Minimum-cycle-slip reception is desirable because maintaining constant track of the phase of the carrier signal from each available GPS satellite is necessary for surveying to centimeter or subcentimeter precision. Even a loss of signal for as short a time as a nanosecond can cause cycle slip. Cycle slips degrade the quality and precision of survey data acquired during a flight. The two principal causes of cycle slip are weakness of signals and multipath propagation. Heretofore, it has been standard practice to mount a GPS antenna rigidly on top of an airplane, and the radiation pattern of the antenna is typically hemispherical, so that all GPS satellites above the horizon are viewed by the antenna during level flight. When the airplane must be banked for a turn or other maneuver, the reception hemisphere becomes correspondingly tilted; hence, the antenna no longer views satellites that may still be above the Earth horizon but are now below the equatorial plane of the tilted reception hemisphere. Moreover, part of the reception hemisphere (typically, on the inside of a turn) becomes pointed toward ground, with a consequent increase in received noise and, therefore, degradation of GPS measurements. To minimize the likelihood of loss of signal and cycle slip, bank angles of remote-sensing survey airplanes have generally been limited to 10 or less, resulting in skidding or slipping uncoordinated turns. An airplane must be banked in order to make a coordinated turn. For small-radius, short-time coordinated turns, it is necessary to employ banks as steep as 45 , and turns involving such banks are times and for confining airplanes as closely as possible to areas to be surveyed. The idea underlying the design is that if the antenna can be kept properly aimed, then the incidence of cycle slips caused by loss or weakness of signals can be minimized. The system includes an articulating GPS antenna and associated electronic circuitry mounted under a radome atop an airplane. The electronic circuitry includes a microprocessor-based interface-circuit-and-data-translation module. The system receives data on the current attitude of the airplane from the inertial navigation system of the airplane. The microprocessor decodes the attitude data and uses them to compute commands for the GPS-antenna-articulating mechanism to tilt the antenna, relative to the airplane, in opposition to the roll or bank of the airplane to keep the antenna pointed toward the zenith. The system was tested aboard the hurricane- hunting airplane of the National Oceanic and Atmospheric Administration (NOAA) [see figure] during an 11-hour flight to observe the landfall of Hurricane Bret in late summer of 1999. No bank-angle restrictions were imposed during the flight. Post-flight analysis of the GPS trajectory data revealed that no cycle slip had occurred.considered normal maneuvers. These steep banks are highly desirable for minimizing flight

Wright, C. Wayne

2009-01-01

247

The Evolution of Global Positioning System (GPS) Technology.  

ERIC Educational Resources Information Center

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

Kumar, Sameer; Moore, Kevin B.

2002-01-01

248

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

249

The BIRD Satellite Mission as a Milestone Toward GPS-based Autonomous Navigation  

Microsoft Academic Search

( ABSTRACT: This paper describes the onboard navigation system ONS for the German BIRD Bi-spectral ) InfraRed Detection microsatellite. BIRD is a technology satellite used for autonomous detection and identifica- tion of hot spots such as forest fires or volcanic activities. The ONS computes the instantaneous nadir and flight direction for camera pointing, as well as precise positions for real-time

EBERHARD GILL; OLIVER MONTENBRUCK; HAKAN KAYAL

2001-01-01

250

Navigation in Antarctica Today: The Global Positioning System  

NSDL National Science Digital Library

From the activities at this site students will discover that before satellite imagery, when scientists navigated by matching up geologic formations with those shown in aerial photographs, they had a tough task in Antarctica where there aren't many visible features. After researching how the Global Positioning System (GPS) 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 two activities including a Web research project on GPS and how it is used today, and a hands-on activity in which students do on paper the work that GPS satellites do in space. There are also question and answer interviews with a geophysicist who maps geologic formations beneath the ice and a glaciologist who studies the movement of the Antarctic ice sheet. Teacher tools include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, a student handout with guidance for putting together a portfolio and examples of creative final projects, and additional readings.

251

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

252

MEMS Based Pedestrian Navigation System  

NASA Astrophysics Data System (ADS)

In this paper we present a micro-electrical mechanical system (MEMS) based pedestrian navigation system (PNS) for seamless positioning. The sub-algorithms for the PNS are developed and the positioning performance is enhanced using the modified receding horizon Kalman finite impulse response filter (MRHKF). The PNS consists of a biaxial accelerometer and a biaxial magnetic compass mounted on a shoe. The PNS detects a step using a novel technique during the stance phase and simultaneously calculates walking information. Step length is estimated using a neural network whose inputs are the walking information. The azimuth is calculated using the magnetic compass, the walking information and the tilt compensation algorithm. Using the proposed sub-algorithms, seamless positioning can be accomplished. However, the magnetic compass based azimuth may have an error that varies according to the surrounding magnetic field. In this paper, the varying error is compensated using the MRHKF filter. Finally, the performance enhanced seamless positioning is achieved, and the performance is verified by experiment.

Cho, Seong Yun; Park, Chan Gook

2006-01-01

253

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.

254

Two Systems of Spatial Representation Underlying Navigation  

PubMed Central

We review evidence for two distinct cognitive processes by which humans and animals represent the navigable environment. One process uses the shape of the extended 3D surface layout to specify the navigator’s position and orientation. A second process uses objects and patterns as beacons to specify the locations of significant objects. Although much of the evidence for these processes comes from neurophysiological studies of navigating animals and neuroimaging studies of human adults, behavioral studies of navigating children shed light both on the nature of these systems and on their interactions.

Lee, Sang Ah; Spelke, Elizabeth S.

2011-01-01

255

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.

256

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.

2008-09-03

257

In-flight detection of errors for enhanced aircraft flight safety and vertical accuracy improvement using digital terrain elevation data with an inertial navigation system, global positioning system and radar altimeter  

Microsoft Academic Search

This dissertation discusses integration architectures using digital terrain elevation data (DTED) with an inertial navigation system (INS), a global positioning system (GPS) and a radar altimeter. Two integration architectures are considered: DTED with INS, GPS and radar altimeter for aircraft vertical accuracy improvement during the final approach; and DTED with kinematic GPS (KGPS) and a radar altimeter for enhanced aircraft

Robert Anthony Gray

1999-01-01

258

Specification of a NAVSTAR Global Positioning System (GPS) receiver for a differential GPS ground system  

NASA Technical Reports Server (NTRS)

One step towards the successful completion of a functional ground unit for the Differential Global Positioning System (DGPS) will be in choosing a currently available GPS receiver that will accurately measure the propagation times of the satellite signals and have the capability to be electrically interfaced with and controlled by a Digital Equipment Corporation (DEC) PDP-11/34A computer. The minimum requirements and characteristics of a NAVSTAR Global Positioning System (GPS) receiver are described. The specific technical specifications addressed include data accuracies and resolutions, receiver interface/external control, enclosure dimensions and mounting requirements, receiver operation, and environmental specifications.

Mccall, D. L.; Turner, R. N.

1984-01-01

259

Inertial/multisensor navigation  

NASA Technical Reports Server (NTRS)

A Multisensor Navigation System as proposed by the Ohio University Avionics Engineering Center is illustrated. The proposed system incorporates radio (Lorac-C), satellite (Global Positioning System) and an inertial navigation system (INS). The inertial part of the system will be of a low grade since the INS will be used primarily for filtering the GPS data and for short term stability. Loran-C and GPS will be used for long term stability.

Alikiotis, Dimitri

1987-01-01

260

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

261

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

262

Comparison of robust H ? filter and Kalman filter for initial alignment of inertial navigation system  

Microsoft Academic Search

There are many filtering methods that can be used for the initial alignment of an integrated inertial navigation system. This\\u000a paper discussed the use of GPS, but focused on two kinds of filters for the initial alignment of an integrated strapdown inertial\\u000a navigation system (SINS). One method is based on the Kalman filter (KF), and the other is based on

Yan-Ling Hao; Ming-Hui Chen; Liang-Jun Li; Bo Xu

2008-01-01

263

Thermal Calibration of MEMS Inertial Sensors for an FPGA-Based Navigation System  

Microsoft Academic Search

Based on a small, lightweight, low-cost high performance inertial Measurement Units (IMU), an effective calibration method is implemented to evaluate the performance of Micro-Electro-Mechanical Systems (MEMS) sensors suffering from various errors to get acceptable navigation results. A prototype development board based on FPGA, dual core processor's configuration for IMU\\/INS\\/GPS integrated navigation system is designed for experimental tests. The significant error

Lei Wang; Yongping Hao; Zesong Wei; Fei Wang

2010-01-01

264

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...

265

Design of Urban Nuclear Accident Emergency Command System Based on Intelligent Navigation  

Microsoft Academic Search

This paper takes the Shenzhen Emergency Command System as an example, then describes and discusses the construction methods and key technologies of the Urban Nuclear Accident Emergency Command System (UNAECS) based on intelligent navigation. This UNAECS adopts the GPS location technology based on space grid and the optimal path algorithm based on the maximum flow analysis, and realizes the dynamic

Yurong Yang; Xiangli Zheng

2010-01-01

266

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

267

Development Of A MultiSensor GNSS Based Vehicle Navigation System  

Microsoft Academic Search

A vehicle navigation system is developed that uses a combination of GPS positioning anddead reckoning sensors. A survey of dead reckoning sensors is presented, includingexamples and comparisons of different technologies. The dead reckoning sensors chosenfor the final implementation were a low cost piezoelectric vibrating gyro and differentialodometry provided by a vehicle's anti-lock braking system. Filtering of the data is doneby

Jim Stephen

2000-01-01

268

MEMS based inertial navigation systems onboard balloons .  

NASA Astrophysics Data System (ADS)

Performances of low-cost inertial navigation sensors, usually poor, can often match different mission requirements by means of a careful signal and data processing and/or an augmentation by means of different observables. The paper presents the LOWCOINS navigation experiment, intended to fly onboard BEXUS balloon mission in late 2008. LOWCOINS has as the main component a low-cost three-axes inertial unit, integrating three accelerometers and three gyros. The slow dynamic typical of a balloon flight is deemed as an ideal test to verify the performances of the unit and to improve the knowledge on the data processing needed to obtain an accurate final navigation solution. In order to enlarge the set of available data, a cluster of magnetometers and a pressure sensor, always belonging to low-cost instrumentation range, are hosted on board. Measurements are both stored on board and downlinked to a ground station. Position and velocity components (both the onboard computed first guess and the post-flight calibrated solution) will be compared with the data gathered by a GPS receiver, which is a standard component of BEXUS balloon avionics. Substantial attention to thermal aspects has been requested in order to cope with environmental conditions prior of and all along the flight. The requested navigation unit case design is shortly reported.

Palmerini, G. B.; Medaglia, E.; Montefusco, P.; Oliva, M. C.

269

Optimum Reset of Ship's Inertial Navigation System  

Microsoft Academic Search

Optimum linear filter and control theory is applied to the practical problem of supplementing an inertial navigation system with discrete reference information. The information takes the form of position obtained from Loran C or Decca, for example, and occasional azimuth fixes obtained from star sightings. In particular, optimum use of this information is discussed for the Ship's Inertial Navigation System

B. E. Bona; Robert J. Smay

1966-01-01

270

Inertial navigation system aided by aircraft dynamics  

Microsoft Academic Search

In this work the possibility of using the model of aircraft dynamics as a means for aiding an inertial navigation system is studied. The method is of particular interest for low-grade inertial navigating system (INS). The aiding formulation is introduced, its corresponding mathematical model is derived and used in the design of an appropriate extended Kalman filter. Sensitivity analysis of

M. Koifman; I. Y. Bar-Itzhack

1999-01-01

271

Fuel-Saving Navigation System in VANETs  

Microsoft Academic Search

Because of shortage of raw materials, the energy-saving issues become popular in Vehicular Ad-hoc Networks (VANETs). A VANET is formed by traveling vehicles with communicating capability and thus it brings various applications. Navigation system is one of important applications in VANETs. The traditional navigation system usually plans a shortest path for users according to geographic maps but the planned path

Po-Yu Chen; Yi-Min Guo; Wen-Tsuen Chen

2010-01-01

272

Spatial Database Modeling for Indoor Navigation Systems  

NASA Astrophysics Data System (ADS)

For many years, cartographers are involved in designing GIS and navigation systems. Most GIS applications use the outdoor data. Increasingly, similar applications are used inside buildings. Therefore it is important to find the proper model of indoor spatial database. The development of indoor navigation systems should utilize advanced teleinformation, geoinformatics, geodetic and cartographical knowledge. The authors present the fundamental requirements for the indoor data model for navigation purposes. Presenting some of the solutions adopted in the world they emphasize that navigation applications require specific data to present the navigation routes in the right way. There is presented original solution for indoor data model created by authors on the basis of BISDM model. Its purpose is to expand the opportunities for use in indoor navigation.

Gotlib, Dariusz; Gnat, Mi?osz

2013-12-01

273

Individual Global Navigation Satellite Systems in the Space Service Volume  

NASA Technical Reports Server (NTRS)

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

Force, Dale A.

2013-01-01

274

Integrated Global Positioning Systems (GPS) Laboratory  

NASA Technical Reports Server (NTRS)

The purpose of this research is to develop a user-friendly Integrated GPS lab manual. This manual will help range engineers at NASA to integrate the use of GPS Simulators, GPS receivers, computers, MATLAB software, FUGAWI software and SATELLITE TOOL KIT software. The lab manual will be used in an effort to help NASA engineers predict GPS Coverage of planned operations and analyze GPS coverage of operation post mission. The Integrated GPS Laboratory was used to do GPS Coverage for two extensive case studies. The first scenario was an airplane trajectory in which an aircraft flew from Cape Canaveral to Los Angeles, California. In the second scenario, a rocket trajectory was done whereas a rocket was launched from Cape Canaveral to one thousand kilometers due east in the Atlantic Ocean.

Brown, Dewayne Randolph

2002-01-01

275

GPS-based system for satellite tracking and geodesy  

NASA Technical Reports Server (NTRS)

High-performance receivers and data processing systems developed for GPS are reviewed. The GPS Inferred Positioning System (GIPSY) and the Orbiter Analysis and Simulation Software (OASIS) are described. The OASIS software is used to assess GPS system performance using GIPSY for data processing. Consideration is given to parameter estimation for multiday arcs, orbit repeatability, orbit prediction, daily baseline repeatability, agreement with VLBI, and ambiguity resolution. Also, the dual-frequency Rogue receiver, which can track up to eight GPS satellites simultaneously, is discussed.

Bertiger, Willy I.; Thornton, Catherine L.

1989-01-01

276

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

277

Analysis of navigation performance for the Earth Observing System (EOS) using the TDRSS Onboard Navigation System (TONS)  

NASA Technical Reports Server (NTRS)

Use of the Tracking and Data Relay Satellite System (TDRSS) Onboard Navigation System (TONS) was proposed as an alternative to the Global Positioning System (GPS) for supporting the Earth Observing System (EOS) mission. The results are presented of EOS navigation performance evaluation with respect to TONS based orbit, time, and frequency determination (OD/TD/FD). Two TONS modes are considered: one uses scheduled TDRSS forward link service to derive one way Doppler tracking data for OD/FD support (TONS-I); the other uses an unscheduled navigation beacon service (proposed for Advanced TDRSS) to obtain pseudorange and Doppler data for OD/TD/FD support (TONS-II). Key objectives of the analysis were to evaluate nominal performance and potential sensitivities, such as suboptimal tracking geometry, tracking contact scheduling, and modeling parameter selection. OD/TD/FD performance predictions are presented based on covariance and simulation analyses. EOS navigation scenarios and the contributions of principal error sources impacting performance are also described. The results indicate that a TONS mode can be configured to meet current and proposed EOS position accuracy requirements of 100 and 50 m, respectively.

Elrod, B.; Kapoor, A.; Folta, David C.; Liu, K.

1991-01-01

278

Hybrid Kalman/H?filter in designing optimal navigation of vehicle in PRT System  

NASA Astrophysics Data System (ADS)

PRT( Personal Rapid Transit ) system is a automated operation, so that it is important exactly finding position of vehicle. Many of PRT system has accepted the GPS system for a position, speed, and direction. in this paper, we propose a combination of Kalman Filter and H? Filter known as Hybrid Kalman/ H? Filter for applying to GPS navigation algorithm. For disturbance cancellation, Kalman Filter is optimal but it requires the statistical information about process and measurement noises while H? Filter only minimizes the "worst-case" error and requires that the noises are bounded. The new Hybrid Filter is expected to reduce the worst-case error and exploit the incomplete knowledge about noises to provide a better estimation. The experiment shows us the ability of Hybrid Filter in GPS navigation algorithm.

Kim, Hyunsoo; Nguyen, Hoang Hieu; Nguyen, Phi Long; Kim, Han Sil; Jang, Young Hwan; Ryu, Myungseon; Choi, Changho

2007-12-01

279

A gradiometric inertial navigation system. II  

NASA Astrophysics Data System (ADS)

Different representations of the error equations for a three-component gradiometric inertial navigation system are obtained. Analytical solutions to these equations are obtained, and the effect of instrument errors on the accuracy of the system is evaluated.

Korotaev, Iu. A.; Kliuev, V. Iu.

1989-02-01

280

National Airspace System. Navigation Operational Concept.  

National Technical Information Service (NTIS)

A requirement for the National Airspace System (NAS) is to provide for navigation, as identified in the NAS System Requirements Specification (NASSRS). The operational concept is one of many high level documents that will, in total, describe the operation...

W. Trent, T. Pickerell, H. Nelson

1991-01-01

281

Ultra-Wideband Tracking System Design for Relative Navigation  

NASA Technical Reports Server (NTRS)

This presentation briefly discusses a design effort for a prototype ultra-wideband (UWB) time-difference-of-arrival (TDOA) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being designed for use in localization and navigation of a rover in a GPS deprived environment for surface missions. In one application enabled by the UWB tracking, a robotic vehicle carrying equipments can autonomously follow a crewed rover from work site to work site such that resources can be carried from one landing mission to the next thereby saving up-mass. The UWB Systems Group at JSC has developed a UWB TDOA High Resolution Proximity Tracking System which can achieve sub-inch tracking accuracy of a target within the radius of the tracking baseline [1]. By extending the tracking capability beyond the radius of the tracking baseline, a tracking system is being designed to enable relative navigation between two vehicles for surface missions. A prototype UWB TDOA tracking system has been designed, implemented, tested, and proven feasible for relative navigation of robotic vehicles. Future work includes testing the system with the application code to increase the tracking update rate and evaluating the linear tracking baseline to improve the flexibility of antenna mounting on the following vehicle.

Ni, Jianjun David; Arndt, Dickey; Bgo, Phong; Dekome, Kent; Dusl, John

2011-01-01

282

Optimum Integration of Aircraft Navigation Systems  

Microsoft Academic Search

A current problem in aircraft navigation is determining how to effect alow cost navigation system consistent with required mission operationswhich will render a high degree of accuracy and reliability. One wayto achieve this is through optimum integration of equipment,subsystems, and computer mechanizations. Consistent with this approach,the overall objectives of this paper are to show the advantages of anoptimally integrated aircraft

William Zimmerman

1969-01-01

283

Navigation and orbit computation aspects of the ESA NAVSAT system concept  

Microsoft Academic Search

The requirements of a civilian, low-cost NAVSAT version of the GPS system are discussed. Six regional ground control facilities would compensate for the lack of autonomous navigation capabilities on the 24 NAVSAT spacecraft, a cost-saving measure. A 12 hr orbit for each satellite would yield two passes per day. The stations would maintain continuous uplinks to provide the satellites with

K. F. Wakker; B. A. C. Ambrosius; H. Leenman; R. Noomen

1985-01-01

284

LOW POWER GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS) SIGNAL DETECTION AND PROCESSING  

Microsoft Academic Search

The ability to detect and process weak Global Navigation Satellite System (GNSS) signals is extremely valuable as the specified received power levels of such signals are already quite low. For example, the GPS-SPS signal specification indicates the signal power at the antenna will be -130 dBm. Such weak detection techniques would be of importance for a number of applications. This

Dennis M. Akos; Per-Ludvig Normark; Jeong-Taek Lee; Konstantin G. Gromov; James B. Y. Tsui; John Schamus; Wright-Patterson AFB

2000-01-01

285

Bayesian Surface and Underwater Navigation  

Microsoft Academic Search

A common framework for maritime surface and underwater (UW) map-aided navigation is proposed as a supplement to satellite navigation based on the global positioning system (GPS). The proposed Bayesian navigation method is based on information from a distance measuring equipment (DME) which is compared with the information obtained from various databases. As a solution to the recursive Bayesian navigation problem,

Rickard Karlsson; Fredrik Gustafsson

2006-01-01

286

GPS-BASED ONLINE CONTROL AND ALARM SYSTEM (GOCA)  

Microsoft Academic Search

A GPS-based online control and alarm system (GOCA) for the monitoring of three-dimensional movements has been developed at the Karlsruhe University of Applied Sciences in cooperation with the EuroNav, Wunstorf. The GOCA hardware consists of an array of GPS sensors and communication units to be placed in the monitoring area. The hardware dependent control software communicates with the GPS sensors

Simone Kälber; Reiner Jäger

287

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

288

Non-GNSS Radio Frequency Navigation.  

National Technical Information Service (NTIS)

There are many situations in which Global Navigation Satellite Systems (GNSS) such as the Global Positioning System (GPS) cannot provide adequate navigation performance (such as indoors or in urban canyons). This paper describes the technical challenges o...

J. Raquet R. K. Martin

2008-01-01

289

System using leo satellites for centimeter-level navigation  

NASA Technical Reports Server (NTRS)

Disclosed herein is a system for rapidly resolving position with centimeter-level accuracy for a mobile or stationary receiver [4]. This is achieved by estimating a set of parameters that are related to the integer cycle ambiguities which arise in tracking the carrier phase of satellite downlinks [5,6]. In the preferred embodiment, the technique involves a navigation receiver [4] simultaneously tracking transmissions [6] from Low Earth Orbit Satellites (LEOS) [2] together with transmissions [5] from GPS navigation satellites [1]. The rapid change in the line-of-sight vectors from the receiver [4] to the LEO signal sources [2], due to the orbital motion of the LEOS, enables the resolution with integrity of the integer cycle ambiguities of the GPS signals [5] as well as parameters related to the integer cycle ambiguity on the LEOS signals [6]. These parameters, once identified, enable real-time centimeter-level positioning of the receiver [4]. In order to achieve high-precision position estimates without the use of specialized electronics such as atomic clocks, the technique accounts for instabilities in the crystal oscillators driving the satellite transmitters, as well as those in the reference [3] and user [4] receivers. In addition, the algorithm accommodates as well as to LEOS that receive signals from ground-based transmitters, then re-transmit frequency-converted signals to the ground.

Rabinowitz, Matthew (Inventor); Parkinson, Bradford W. (Inventor); Cohen, Clark E. (Inventor); Lawrence, David G. (Inventor)

2002-01-01

290

An improved regularized particle filter for GPS\\/INS integration  

Microsoft Academic Search

Hybridization techniques receive a renewed interest due to recent navigation systems such as Galileo. Hybridization takes advantage of the complementarity of different sensor types to increase navigation performance. This study focuses on the integration of the Global Positioning System (GPS) and the inertial navigation systems (INS). GPS allows to compensate for the long term drift of INS estimates, while aided

Audrey Giremus; Jean-Yves Tourneret; P. M. Djuric

2005-01-01

291

The use of GPS for vehicle stability control systems  

Microsoft Academic Search

This paper presents a method for using global positioning system (GPS) velocity measurements to improve vehicle lateral stability control systems. GPS can be used to calculate the sideslip angle of a vehicle without knowing the vehicle model. This measurement is combined with other traditional measurements to control the lateral motion of the vehicle. Noise estimates are provided for all measurement

Robert Daily; David M. Bevly

2004-01-01

292

GPS Monitor Station Upgrade Program at the Naval Research Laboratory.  

National Technical Information Service (NTIS)

One of the measurements made by the Global Positioning System (GPS) monitor stations is to measure the continuous pseudo-range of all the passing GPS satellites. The pseudo-range contains GPS and monitor station clock errors as well as GPS satellite navig...

I. J. Galysh D. M. Craig

1996-01-01

293

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation...Special Committee 159 meeting: Global Positioning System (GPS...RTCA Special Committee 159: Global Positioning System (GPS). DATES: The...

2011-06-07

294

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation...Special Committee 159 meeting: Global Positioning System (GPS...RTCA Special Committee 159: Global Positioning System (GPS). DATES: The...

2011-05-12

295

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159, Global Positioning Systems (GPS) AGENCY: Federal Aviation...RTCA Special Committee 159, Global Positioning Systems (GPS...RTCA Special Committee 159, Global Positioning Systems (GPS). DATES: The...

2013-02-27

296

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation...Special Committee 159 meeting: Global Positioning System (GPS...RTCA Special Committee 159: Global Positioning System (GPS) 87th meeting....

2011-10-28

297

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159: Global Positioning System (GPS). AGENCY: Federal Aviation...Special Committee 159 meeting: Global Positioning System (GPS...RTCA Special Committee 159: Global Positioning System (GPS). DATES: The...

2010-10-06

298

75 FR 2581 - Eighty-First Meeting: RTCA Special Committee 159: Global Positioning System (GPS)  

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation...Special Committee 159 meeting: Global Positioning System (GPS...RTCA Special Committee 159: Global Positioning System (GPS). DATES: The...

2010-01-15

299

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159, Global Positioning Systems (GPS) AGENCY: Federal Aviation...RTCA Special Committee 159, Global Positioning Systems (GPS...RTCA Special Committee 159, Global Positioning Systems (GPS). DATES: The...

2012-09-12

300

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159, Global Positioning System (GPS) AGENCY: Federal Aviation...RTCA Special Committee 159, Global Positioning System (GPS...RTCA Special Committee 159, Global Positioning System (GPS). DATES: The...

2012-02-28

301

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

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159, Global Positioning Systems (GPS) AGENCY: Federal Aviation...RTCA Special Committee 159, Global Positioning Systems (GPS...RTCA Special Committee 159, Global Positioning Systems (GPS) DATES: The...

2013-09-19

302

75 FR 28318 - Eighty-Second Meeting: RTCA Special Committee 159: Global Positioning System (GPS)  

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 159: Global Positioning System (GPS) AGENCY: Federal Aviation...Special Committee 159 meeting: Global Positioning System (GPS...RTCA Special Committee 159: Global Positioning System (GPS). DATES: The...

2010-05-20

303

Orion Absolute Navigation System Progress and Challenge  

NASA Technical Reports Server (NTRS)

The absolute navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.

Holt, Greg N.; D'Souza, Christopher

2012-01-01

304

Rip current monitoring using GPS buoy system  

NASA Astrophysics Data System (ADS)

The occurrence of rip current in the Haeundae beach, which is one of the most famous beaches in South Korea, has been threatening beach-goers security in summer season annually. Many coastal scientists have been investigating rip currents by using field observations and measurements, laboratory measurements and wave tank experiments, and computer and numerical modeling. Rip current velocity is intermittent and may rapidly increase within minutes due to larger incoming wave groups or nearshore circulation instabilities. It is important to understand that changes in rip current velocity occur in response to changes in incoming wave height and period as well as changes in water level. GPS buoys have been used to acquire sea level change data, atmospheric parameters and other oceanic variables in sea for the purposes of vertical datum determination, tide correction, radar altimeter calibration, ocean environment and marine pollution monitoring. Therefore, we adopted GPS buoy system for an experiment which is to investigate rip current velocity; it is sporadic and may quickly upsurge within minutes due to larger arriving wave groups or nearshore flow uncertainties. In this study, for high accurate positioning of buy equipment, a Satellite Based Argumentation System DGPS data logger was deployed to investigate within floating object, and it can be acquired three-dimensional coordinate or geodetic position of buoy with continuous NMEA-0183 protocol during 24 hours. The wave height measured by in-situ hydrometer in a cross-shore array clearly increased before and after occurrence of rip current, and wave period also was lengthened around an event. These results show that wave height and period correlate reasonably well with long-shore current interaction in the Haeundae beach. Additionally, current meter data and GPS buoy data showed that rip current velocities, about 0.2 m/s, may become dangerously strong under specific conditions. Acknowledgement This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology(2010-0024670)

Song, DongSeob; Kim, InHo; Kang, DongSoo

2014-05-01

305

A technical note on GPS Navstar Pseudo Random Noise Signal Assembly (PRNSA)  

Microsoft Academic Search

The payload of the GPS navigation satellite is the Pseudo Random Noise Signal Assembly (PRNSA). In the operational configuration of the GPS Navigation System, each satellite of an 18 Satellite Constellation continuously transmits this unique pseudo random noise coded navigational data, modulated on an L-band carrier, to all GPS users. The major characteristics of the PRNSA are described with some

P. T. Domanico

1983-01-01

306

Ionospheric scintillation effects on single frequency GPS  

Microsoft Academic Search

Ionospheric scintillation of Global Positioning System (GPS) signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active within, although not limited to, a belt encircling the Earth within 20 degrees of the geomagnetic equator. As GPS applications and users increase, so does the potential for degraded precision and availability from scintillation. We examined

R. A. Steenburgh; C. G. Smithtro; K. M. Groves

2008-01-01

307

The GPS Space Service Volume  

NASA Technical Reports Server (NTRS)

Prior to the advent of artificial satellites, the concept of navigating in space and the desire to understand and validate the laws of planetary and satellite motion dates back centuries. At the initiation of orbital flight in 1957, space navigation was dominated by inertial and groundbased tracking methods, underpinned by the laws of planetary motion. It was early in the 1980s that GPS was first explored as a system useful for refining the position, velocity, and timing (PVT) of other spacecraft equipped with GPS receivers. As a result, an entirely new GPS utility was developed beyond its original purpose of providing PVT services for land, maritime, and air applications. Spacecraft both above and below the GPS constellation now receive the GPS signals, including the signals that spill over the limb of the Earth. The use of radionavigation satellite services for space navigation in High Earth Orbits is in fact a capability unique to GPS. Support to GPS space applications is being studied and planned as an important improvement to GPS. This paper discusses the formalization of PVT services in space as part of an overall GPS improvement effort. It describes the GPS Space Service Volume (SSV) and compares it to the Terrestrial Service Volume (TSV). It also discusses SSV coverage with the current GPS constellation, coverage characteristics as a function of altitude, expected power levels, and coverage figures of merit.

Bauer, F. H.; Moreau, M. C.; Dahle-Melsaether, M. E.; Petrofski, W. P.; Stanton, B. J.; Thomason, S.; Harris, G. A.; Sena, R. P.; Temple, L. Parker, III

2006-01-01

308

Sigma-point Kalman filtering for integrated GPS and inertial navigation  

Microsoft Academic Search

A sigma-point Kalman filter is derived for integrating GPS measurements with inertial measurements from gyros and accelerometers to determine both the position and the attitude of a moving vehicle. Sigma-point filters use a carefully selected set of sample points to more accurately map the probability distribution than the linearization of the standard extended Kalman filter (KKF), leading to faster convergence

J. L. Crassidis

2006-01-01

309

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

310

Inertial navigation system for bladder endoscopy.  

PubMed

The usage of video endoscopes in cystoscopic interventions of the urinary bladder impedes an intuitive navigation. Although image-based solutions such as panorama images can provide extended views of the surgical field, a real-time 3-D navigation is not supported. Furthermore, the integration of common tracking systems in ambulant clinics is often hindered due to low usability and high costs. Thus, we discuss in this paper a first low-cost inertial navigation system. Our evaluation results show that in spite of lower sensor accuracies, mean errors between < 1° and 4° are achieved for solid angles. Using endoscopes with different view angles we apply an extended endoscope model for an adaptive displacement correction. Furthermore, we implement a first guided navigation tool for tumor re-identification in real-time. PMID:22255553

Behrens, Alexander; Grimm, Jonathan; Gross, Sebastian; Aach, Til

2011-01-01

311

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

Microsoft Academic Search

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

K. Parameswaran; Korak Saha; C. Suresh Raju

2008-01-01

312

NASA Tracking Ship Navigation Systems.  

National Technical Information Service (NTIS)

The ship position and attitude measurement system that was installed aboard the tracking ship Vanguard is described. An overview of the entire system is given along with a description of how precise time and frequency is utilized. The instrumentation is b...

J. J. Mckenna

1976-01-01

313

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

314

A computer system for geosynchronous satellite navigation  

NASA Technical Reports Server (NTRS)

A computer system specifically designed to estimate and predict Geostationary Operational Environmental Satellite (GOES-4) navigation parameters using Earth imagery is described. The estimates are needed for spacecraft maneuvers while prediction provide the capability for near real-time image registration. System software is composed of four functional subsystems: (1) data base management; (2) image processing; (3) navigation; and (4) output. Hardware consists of a host minicomputer, a cathode ray tube terminal, a graphics/video display unit, and associated input/output peripherals. System validity is established through the processing of actual imagery obtained by sensors on board the Synchronous Meteorological Satellite (SMS-2). Results indicate the system is capable of operationally providing both accurate GOES-4 navigation estimates and images with a potential registration accuracy of several picture elements (pixels).

Koch, D. W.

1980-01-01

315

Flight-control/navigation inertial reference system  

NASA Technical Reports Server (NTRS)

The preliminary design of a redundant strapdown navigation system for integrated flight-control/navigation use has been completed. Based on application of tuned-gimbal gyros, a compact configuration (13 in x 13 in x 14 in) has been achieved for fail-operational/fail-operational redundancy. Test data are presented for strapdown system test programs including flight testing of the LN-50 tuned-gimbal gyro system. Testing of a redundant sensor configuration is currently in process. Strapdown gyro development also includes ring laser and nuclear magnetic resonance techniques.

Ebner, R. E.

1977-01-01

316

Inertial navigation sensor integrated obstacle detection system  

NASA Technical Reports Server (NTRS)

A system that incorporates inertial sensor information into optical flow computations to detect obstacles and to provide alternative navigational paths free from obstacles. The system is a maximally passive obstacle detection system that makes selective use of an active sensor. The active detection typically utilizes a laser. Passive sensor suite includes binocular stereo, motion stereo and variable fields-of-view. Optical flow computations involve extraction, derotation and matching of interest points from sequential frames of imagery, for range interpolation of the sensed scene, which in turn provides obstacle information for purposes of safe navigation.

Bhanu, Bir (Inventor); Roberts, Barry A. (Inventor)

1992-01-01

317

Multisensor navigation system for an autonomous helicopter  

Microsoft Academic Search

Autonomous unmanned aerial vehicles (UAVs) require avionics systems that enable them to maintain a stable attitude and to follow a desired flight path. This paper considers the design and development of such an avionics system that provides navigational and terrain information to the flight computer of a rotorcraft UAV. The process includes the design and testing of flight hardware and

Joerg S. Dittrich; Eric N. Johnson

2002-01-01

318

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

319

Omega Fixing for Integrated Navigation Systems.  

National Technical Information Service (NTIS)

A research program was carried out to define the use of Omega fixing for the Integrated Navigation System. For this purpose, the Omega system was analyzed for accuracy, and in particular, the actual value of the sky-wave corrections (SWC) against the tabu...

A. Sposito V. Nastro A. Russo

1974-01-01

320

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

321

Research of GPS integrity monitoring  

Microsoft Academic Search

Integrity is one of the four basic parameters (accuracy, continuity and availability as the other three) which are used to assess the performance of satellite navigation systems. This paper introduces the basic concept of integrity and analyses the factors which affect the integrity of GPS. Focusing on the three main components of GPS and in terms of the object to

Xia-qiong Yu; Xu-rong Dong; Bin Tang; Xiao-yu Huang

2007-01-01

322

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

323

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.

324

Observability studies of inertial navigation systems  

NASA Technical Reports Server (NTRS)

The present work deals with an undamped three-channel inertial-navigation-system error model. It is shown that it is possible to fully observe, and thus estimate, all the states of the system. This is in contrast to a previous two-channel system, in which it was impossible to fully observe and estimate all the states of the system. The conclusions of the analysis are verified through covariance simulation, which yields identical results.

Bar-Itzhack, I. Y.; Goshen-Meskin, D.

1989-01-01

325

Accuracy of ESG monitor\\/sins inertial navigation system  

Microsoft Academic Search

Discussed and analyzed is a marine navigation system in which a high performance system, the Ships Inertial Navigation System (SINS), is monitored by an even more accurate system now under development, the Electrostatically Supported Gyro Navigator (ESGN). An advantage of this monitor configuration is a potentially substantial improvement in navigational accuracy, while imposing a minimal change to the existing system.

A. Dushman; H. Sandberg

1973-01-01

326

Autonomous system for cross-country navigation  

NASA Astrophysics Data System (ADS)

Autonomous cross-country navigation is essential for outdoor robots moving about in unstructured environments. Most existing systems use range sensors to determine the shape of the terrain, plan a trajectory that avoids obstacles, and then drive the trajectory. Performance has been limited by the range and accuracy of sensors, insufficient vehicle-terrain interaction models, and the availability of high-speed computers. As these elements improve, higher- speed navigation on rougher terrain becomes possible. We have developed a software system for autonomous navigation that provides for greater capability. The perception system supports a large braking distance by fusing multiple range images to build a map of the terrain in front of the vehicle. The system identifies range shadows and interpolates undersamples regions to account for rough terrain effects. The motion planner reduces computational complexity by investigating a minimum number of trajectories. Speeds along the trajectory are set to provide for dynamic stability. The entire system was tested in simulation, and a subset of the capability was demonstrated on a real vehicle. Results to date include a continuous 5.1 kilometer run across moderate terrain with obstacles. This paper begins with the applications, prior work, limitations, and current paradigms for autonomous cross-country navigation, and then describes our contribution to the area.

Stentz, Anthony; Brumitt, Barry L.; Coulter, R. C.; Kelly, Alonzo

1993-05-01

327

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

328

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

329

Global Navigation Satellite System Software Defined Radio.  

National Technical Information Service (NTIS)

There are two major trends that are driving the nature of GNSS receiver development today. First, there is a growing number of Global Navigation Satellite Systems (GNSS) that exist or are under development, so that in the near future, users will potential...

J. McGinthy

2010-01-01

330

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

331

A Review of Multisensor Fusion Methodologies for Aircraft Navigation Systems  

Microsoft Academic Search

This paper reviews currently existing fault-tolerant navigation system architectures and data fusion methods used in the design and development of integrated aircraft navigation systems and also compares their advantages and disadvantages. Four fault-tolerant navigation system architectures are reviewed and the associated Kalman filter architectures and algorithms are discussed. These techniques have been used in most integrated aircraft navigation systems. The

David J. Allerton; Huamin Jia

2005-01-01

332

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

Federal Register 2010, 2011, 2012, 2013

...Establishment and Amendment of Area Navigation (RNAV) Routes; Alaska AGENCY: Federal...to establish two and modify four Area Navigation (RNAV) routes in Alaska. T and Q-routes...Positioning System (GPS)/ Global Navigation Satellite System (GNSS)...

2010-06-07

333

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

Federal Register 2010, 2011, 2012, 2013

...Establishment and Amendment of Area Navigation (RNAV) Routes; Alaska AGENCY: Federal...establishes two and modifies four Area Navigation (RNAV) routes in Alaska. T and Q-routes...Positioning System (GPS)/Global Navigation Satellite System (GNSS)...

2010-11-09

334

Redundant Strapdown Laser Gyro Navigation System  

NASA Technical Reports Server (NTRS)

For the last several years, NASA has pursued the development of low-cost high-reliability inertial navigation systems that would satisfy a broad spectrum of future space and avionics missions. Two specific programs have culminated in the construction of a Redundant Strapdown Laser Gyro Navigation System. These two programs were for development of a space ultrareliable modular computer (SUMC) and a redundant laser gyro inertial measurement unit (IMU). The SUMC is a digital computer that employs state-of-the-art large-scale integrated circuits configured in a functional modular breakdown. The redundant laser gyro IMU is a six-pack strapdown sensor package in a dodecahedron configuration which uses six laser gyros to provide incremental angular positions and six accelerometers for linear velocity outputs. The sensor arrangement allows automatic accommodation of two failures; a third failure can be tolerated provided it can be determined. The navigation system also includes redundant power supplies, built-in test-equipment (BITE) circuits for failure detection, and software which provides for navigation, redundancy management, and automatic calibration and alignment.

Mcpherson, B. W.; Walls, B. F.; White, J. B.

1976-01-01

335

An overview of space and aircraft navigation  

Microsoft Academic Search

Recent developments connected with the utilization of navigation satellites for the GPS and for air traffic control are reviewed. Consideration is given to the airspace management system and to the operating principles of STAR GPS. The future prospects of navigation satellites are assessed.

Tatsukichi Koshio

1987-01-01

336

Visual navigation system for autonomous indoor blimps  

NASA Astrophysics Data System (ADS)

Autonomous dirigibles - aerial robots that are a blimp controlled by computer based on information gathered by sensors - are a new and promising research field in Robotics, offering several original work opportunities. One of them is the study of visual navigation of UAVs. In the work described in this paper, a Computer Vision and Control system was developed to perform automatically very simple navigation task for a small indoor blimp. The vision system is able to track artificial visual beacons - objects with known geometrical properties - and from them a geometrical methodology can extract information about orientation of the blimp. The tracking of natural landmarks is also a possibility for the vision technique developed. The control system uses that data to keep the dirigible on a programmed orientation. Experimental results showing the correct and efficient functioning of the system are shown and have your implications and future possibilities discussed.

Campos, Mario F.; de Souza Coelho, Lucio

1999-07-01

337

GOES image navigation and registration system  

NASA Astrophysics Data System (ADS)

The GOES I-M image navigation and registration (INR) system was developed and patented by Space Systems/Loral in response to NASA/NOAA pointing requirements of Imager and Sounder payloads. This INR system is divided into space segment and ground segment. The space segment consist of image motion compensation (IMC) system that compensates for deterministic errors caused by orbit and attitude motions and mirror motion compensations system that compensates for spacecraft attitude motion caused by Imager and Sounder scanner mirror motion. The ground segment consists mainly of Orbit and Attitude Tracking System (OATS) that determines the IMC orbit and attitude coefficients from star, landmark, and range measurements.

Kamel, Ahmed

1996-10-01

338

Vision-Based Estimation for Guidance, Navigation, and Control of an Aerial Vehicle  

Microsoft Academic Search

While a Global Positioning System (GPS) is the most widely used sensor modality for aircraft navigation, researchers have been motivated to investigate other navigational sensor modalities because of the desire to operate in GPS denied environments. Due to advances in computer vision and control theory, monocular camera systems have received growing interest as an alternative\\/collaborative sensor to GPS systems. Cameras

M. K. Kaiser; N. R. Gans; W. E. Dixon

2010-01-01

339

Performance of GPS-Aided INS During High-Dynamic Maneuvers.  

National Technical Information Service (NTIS)

This thesis explores the unstable characteristic of an integrated inertial navigation system (INS) and Global Positioning System (GPS) receiver. During high-dynamic maneuvers, the INS Kalman filter provides velocity estimates to the GPS receiver code loop...

J. R. Cunningham

1987-01-01

340

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

341

Lunar Navigation Determination System - LaNDS  

NASA Technical Reports Server (NTRS)

A portable comprehensive navigational system has been developed that both robotic and human explorers can use to determine their location, attitude, and heading anywhere on the lunar surface independent of external infrastructure (needs no Lunar satellite network, line of sight to the Sun or Earth, etc.). The system combines robust processing power with an extensive topographical database to create a real-time atlas (GIS Geospatial Information System) that is able to autonomously control and monitor both single unmanned rovers and fleets of rovers, as well as science payload stations. The system includes provisions for teleoperation and tele-presence. The system accepts (but does not require) inputs from a wide range of sensors. A means was needed to establish a location when the search is taken deep in a crater (looking for water ice) and out of view of Earth or any other references. A star camera can be employed to determine the user's attitude in menial space and stellar map in body space. A local nadir reference (e.g., an accelerometer that orients the nadir vector in body space) can be used in conjunction with a digital ephemeris and gravity model of the Moon to isolate the latitude, longitude, and azimuth of the user on the surface. That information can be used in conjunction with a Lunar GIS and advanced navigation planning algorithms to aid astronauts (or other assets) to navigate on the Lunar surface.

Quinn, David; Talabac, Stephen

2012-01-01

342

of the Theory of Relativity in the GPS  

Microsoft Academic Search

The Global Positioning System (GPS) is a world wide navigation system run by the United State Department of Defense. The GPS is based on a constellation of NAVSTAR satellites and provides reliable positioning and timing data at any time all over the world. Since the services of the GPS are open to the public due to the availability of receiver

Mario Haustein

343

Space shuttle navigation analysis  

NASA Technical Reports Server (NTRS)

A detailed analysis of space shuttle navigation for each of the major mission phases is presented. A covariance analysis program for prelaunch IMU calibration and alignment for the orbital flight tests (OFT) is described, and a partial error budget is presented. The ascent, orbital operations and deorbit maneuver study considered GPS-aided inertial navigation in the Phase III GPS (1984+) time frame. The entry and landing study evaluated navigation performance for the OFT baseline system. Detailed error budgets and sensitivity analyses are provided for both the ascent and entry studies.

Jones, H. L.; Luders, G.; Matchett, G. A.; Sciabarrasi, J. E.

1976-01-01

344

A MMC/MIMU/GPS integrated attitude and azimuth determination system  

NASA Astrophysics Data System (ADS)

Exact knowledge of attitude and azimuth is a fundamental factor in steering vehicle and robot (called carrier in this paper). Micro inertial measurement unit (MIMU), i.e. IMU made by silicon MEMS inertial sensors, GPS and MEMS magnetic compass (MMC), are often used in traditional low-cost attitude and azimuth determination solutions. The main discrepancy, in all of these low-cost approaches, is that the azimuth output is affected by acceleration and turns for long-playing carriers. This paper puts forward a MMC/MIMU/GPS integrated system and an iterative attitude & azimuth determination algorithm for long-playing accelerated carrier's motion. GPS output (.i.e. position and velocity), in ENU (East-North-Upward) navigation frame is transformed into body frame by transformation matrix Cbn. By integrating the MIMU and GPS measurements, through Kalman Filter (KF), the three orthogonal components of the gravity vector are precisely estimated in body frame despite the acceleration effects. Pitch and roll angles are calculated by gravity vector components in body frame, where as azimuth angle is calculated by combining pitch angle, roll angle and MMC output. The direction cosine matrix Cbn, updated by the latest azimuth, roll and pitch angles, is used in next round of this iterative attitude & azimuth determination algorithm. CFAR (Constant False Alarm Rate) filters have been utilized to suppress the noise in GPS data caused by differential operation. The proposed iterative algorithm has been practically implemented and simulated. The simulations results prove the ability of the MMC/MIMU/GPS integrated system to determine the attitude and azimuth for long-playing carrier in any motion situation.

Sheng, Wei; Ma, Yanwu; Cao, Juanjuan

2008-11-01

345

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

346

Inertial navigation systems for mobile robots  

Microsoft Academic Search

A low-cost solid-state inertial navigation system (INS) for mobile robotics applications is described. Error models for the inertial sensors are generated and included in an extended Kalman filter (EKF) for estimating the position and orientation of a moving robot vehicle. Two different solid-state gyroscopes have been evaluated for estimating the orientation of the robot. Performance of the gyroscopes with error

Billur Barshan; Hugh F. Durrant-Whyte

1995-01-01

347

The role of dead reckoning and inertial sensors in future general aviation navigation  

Microsoft Academic Search

Possible configurations for a general aviation autonomous navigation system are studied. Doubtless, an advanced GPS receiver is a “must have” system component. GPS has had some outages due to unintentional interference or even intentional jamming and aircraft should be able to navigate through such an event. Natural candidates for GPS backup are inertial sensors, magnetic compass, and air-speed sensors. All

Zeev Berman; J. David Powell

1998-01-01

348

GLONASS-R: GNSS reflectometry with a Frequency Division Multiple Access-based satellite navigation system  

NASA Astrophysics Data System (ADS)

The information from reflected Global Navigation Satellite System (GNSS) signals can become a valuable data source, from which geophysical properties can be deduced. This approach, called GNSS Reflectometry (GNSS-R), can be used to develop instruments that act like an altimeter when arrival times of direct and reflected signals are compared. Current GNSS-R systems usually entirely rely on signals from the Global Positioning Service (GPS), and field experiments could demonstrate that information from such systems can measure sea level with an accuracy of a few centimeters. However, the usage of the Russian GLONASS system has the potential to simplify the processing scheme and to allow handling of direct and reflected signals like a bistatic radar. Thus, such a system has been developed and deployed for test purposes at the Onsala Space Observatory, Sweden, that has an operational GPS-based GNSS-R system. Over a period of 2 weeks in October 2013, GPS-based GNSS-R sea level monitoring and measurements with the newly developed GLONASS-R system were carried out in parallel. In addition, data from colocated tide gauge measurements were available for comparison. It can be shown that precision and accuracy of the GLONASS-based GNSS-R system is comparable to, or even better than, conventional GPS-based GNSS-R solutions. Moreover, the simplicity of the newly developed GLONASS-R system allows to make it a cheap and valuable tool for various remote sensing applications.

Hobiger, T.; Haas, R.; Löfgren, J. S.

2014-04-01

349

Fiber optic gyroscopes for vehicle navigation systems  

NASA Astrophysics Data System (ADS)

Fiber optic gyroscopes (FOGs) have been developed for vehicle navigation systems and are used in Toyota Motor Corporation models Mark II, Chaser and Cresta in Japan. Use of FOGs in these systems requires high reliability under a wide range of conditions, especially in a temperature range between -40 and 85 degree(s)C. In addition, a high cost-performance ratio is needed. We have developed optical and electrical systems that are inexpensive and can perform well. They are ready to be mass-produced. FOGs have already been installed in luxury automobiles, and will soon be included in more basic vehicles. We have developed more inexpensive FOGs for this purpose.

Kumagai, Tatsuya; Soekawa, Hirokazu; Yuhara, Toshiya; Kajioka, Hiroshi; Oho, Shigeru; Sonobe, Hisao

1994-03-01

350

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

351

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

352

On Navigation Systems for Motorcycles: The Influence and Estimation of Roll Angle  

NASA Astrophysics Data System (ADS)

Vehicle navigation systems use various sensors and the global positioning system (GPS) to locate a vehicle. This location is then matched to a map database to provide navigation information. Between GPS updates, the vehicle's heading angle and forward speed are used to “dead reckon” its position. Heading angle is often measured by integrating the output of a rate gyroscope. For this measurement to be equal to the vehicle's heading angle, the vehicle should not experience any rotation about its roll or pitch axes. For an automobile, the roll and pitch angles are small and may be neglected for the purposes of navigation. This article demonstrates that this same assumption is not true for a motorcycle. Through simulation, it is shown that for a motorcycle, obtaining a meaningful heading angle from a single angular rate measurement requires accounting for the motorcycle's roll angle. Methods to estimate roll angle and heading angle from available navigation measurements are presented, and two possible sensor configurations are compared. A motorcycle navigation scheme based on these roll angle estimation methods is shown to produce exceptional results in a simulation environment.

Coaplen, Joshua P.; Kessler, Patrick; O'Reilly, Oliver M.; Stevens, Dan M.; Hedrick, J. Karl

2005-09-01

353

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

354

Outdoor Navigation  

Microsoft Academic Search

\\u000a Today’s outdoor navigation systems are based on various advanced technologies. The main technologies include geo-positioning\\u000a to determine the current location of a user in real time (e.g., using GPS), wireless communication to obtain updated data\\u000a about traffic and weather in real time and\\/or to provide navigation services via remote servers, and database for storage\\u000a of spatial and non-spatial data in

Hassan A. Karimi

355

Effects of Multipath and Signal Blockage on GPS Navigation in the Vicinity of the International Space Station (ISS)  

Microsoft Academic Search

A number of studies have examined GPS relative navi- gation for spacecraft performing rendezvous and docking with the International Space Station (ISS). However, these studies have not accounted for degradation in GPS naviga- tion performance due to multipath signals being reflected off of the ISS or blockage of GPS signals by the ISS. The objective of this study is to

David E. Gaylor; E. Glenn Lightsey; Kevin W. Key

356

Aircraft Navigation: Design Theory for A Self-Organizing, High Accuracy Navigation System  

Microsoft Academic Search

Aircraft navigation system accuracy can be optimized by proper integration of present subsystems. The Loran-C coordinate converter is a new tool which facilitates the system integration task. Certain navigation devices, e.g., a doppler-free-gyro subsystem, are calibrated in-flight to yield a much better total navigation system. Self-organizing features are included to perform simple decision-making functions automatically and thus, release the human

V. J. Burns

1963-01-01

357

Ionosphere Delay Calibration and Calibration Errors for Satellite Navigation of Aircraft.  

National Technical Information Service (NTIS)

The Federal Aviation Administration (FAA) is implementing a satellite-based navigation system for aircraft using the Global Positioning System (GPS). Positioning accuracy of a few meters will be achieved by broadcasting corrections to the direct GPS signa...

I. Harris A. Manucci B. Iijima U. Lindqwister D. Muna X. Pi B. Wilson

2000-01-01

358

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

359

System architecture study of an orbital GPS user terminal  

NASA Technical Reports Server (NTRS)

The generic RF and applications processing requirements for a GPS orbital navigator are considered. A line of demarcation between dedicated analog hardware, and software/processor implementation, maximizing the latter is discussed. A modular approach to R/PA design which permits several varieties of receiver to be constructed from basic components is described. It is a basic conclusion that software signal processing of the output of the baseband correlator is the best choice of transition from analog to digital signal processing. High performance sets requiring multiple channels are developed from a generic design by replicating the RF processing segment, and modifying the applications software to provide enhanced state propagation and estimation.

Martin, D. P.; Neily, C. M., Jr.

1980-01-01

360

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

361

High-precision kinematic GPS differential positioning and integration of GPS with a ring laser strapdown inertial system  

NASA Astrophysics Data System (ADS)

Many fields, such as geodetic surveying, positioning of airborne sensors (photogrammetric cameras), laser bathymetry, airborne gravimetry, and hydrographic surveys, require accuracies in the decimeter or even centimeter range in differential positioning. Using the full potential of the GPS in a dynamic environment, the Institute of Astronomical and Physical Geodesy (IAPG) has carried out several kinematic tests with respect to land-based, shipborne, and airborne applications. After reviewing the main concepts in differential GPS kinematic positioning, this paper presents experiences with and practical results of kinematic GPS tests. Results of a Kalman filter covariance analysis are shown for the integration of GPS phase and pseudorange data with ring laser strapdown inertial systems in order to recover cycle slips and short-time loss of lock in GPS. In particular, the question is discussed of the extent to which inertial strapdown systems can be used to bridge these times and to maintain centimeter accuracy.

Hein, Guenter W.; Baustert, Gerald; Eissfeller, Bernd; Landau, Herbert

362

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

363

Design study of a low cost civil aviation GPS receiver system  

NASA Technical Reports Server (NTRS)

A low cost Navstar receiver system for civil aviation applications was defined. User objectives and constraints were established. Alternative navigation processing design trades were evaluated. Receiver hardware was synthesized by comparing technology projections with various candidate system designs. A control display unit design was recommended as the result of field test experience with Phase I GPS sets and a review of special human factors for general aviation users. Areas requiring technology development to ensure a low cost Navstar Set in the 1985 timeframe were identified.

Cnossen, R.; Gilbert, G. A.

1979-01-01

364

Integrated Approach to Electronic Navigation.  

National Technical Information Service (NTIS)

While the Global Positioning System (GPS) is and will continue to be an excellent navigation system, it is neither flawless nor is it the only system employed in the navigation of today's seagoing warfighters. The modern warfighter must operate with domin...

P. Shaw B. Pettus

2001-01-01

365

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

366

A new technique for quality control in GPS kinematic positioning  

Microsoft Academic Search

Quality control of information acquired from GPS has become a prime concern to civil users in the field of kinematic positioning. This is mainly because GPS data is subject to blunders that, if left undetected, would significantly degrade the overall performance and threaten the accuracy, reliability and repeatability of the results. With the current revolutionary development of GPS-based navigation systems,

Mohamed A. Abousalem; J. F. McLellan; Edward J. Krakiwsky

1994-01-01

367

GPS Tracking of Sounding Rockets - A European Perspective  

Microsoft Academic Search

Following a series of initial qualification flights, GPS is today considered as a promising and feasible track ing technology within the European sounding rocket program. Compared to traditional radar systems, GPS offers an improved accuracy as well as the onboard availability of navigation and timing information. Difficulties in the use of GPS on sounding rockets stem from the high dynamics

Oliver Montenbruck; Markus Markgraf; Peter Turner; Wolfgang Engler; Günter Schmitt

368

International GPS (Global Positioning System) Service for Geodynamics  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

369

A precise GPS-based time and frequency system  

Microsoft Academic Search

An approach to implementing a compact, highly reliable and precise Master Time and Frequency subsystem usable in a variety of applications is described. These applications include, among others, Satellite Ground Terminals, Range Timing Stations, Communications Terminals, and Power Station Timing subsystems. All time and frequency output signals are locked to Universal Time via the GPS Satellite system. The system provides

Jack McNabb; Earl Fossler

1993-01-01

370

GPS-based mapping system reveals lightning inside storms  

Microsoft Academic Search

Great Plains storms are known for their ability to produce severe weather. They are also prodigious producers of lightning; just how prodigious has been vividly illustrated by observations in central Oklahoma with a new Global Positioning System (GPS)-based lightning mapping system.The observations are useful not only for studying storm electrification but also provide a valuable indicator of storm structure and

Paul R. Krehbiel; Ronald J. Thomas; William Rison; Timothy Hamlin; Jeremiah Harlin; Michael Davis

2000-01-01

371

Simulation of Guidance, Navigation, and Control Systems for Formation Flying Missions  

NASA Technical Reports Server (NTRS)

Concepts for missions of distributed spacecraft flying in formation abound. From high resolution interferometry to spatially distributed in-situ measurements, these mission concepts levy a myriad of guidance, navigation, and control (GNC) requirements on the spacecraft/formation as a single system. A critical step toward assessing and meeting these challenges lies in realistically simulating distributed spacecraft systems. The Formation Flying TestBed (FFTB) at NASA Goddard Space Flight Center's (GSFC) Guidance, Navigation, and Control Center is a hardware-in-the-loop simulation and development facility focused on GNC issues relevant to formation flying systems. The FFTB provides a realistic simulation of the vehicle dynamics and control for formation flying missions in order to: (1) conduct feasibility analyses of mission requirements, (2) conduct and answer mission and spacecraft design trades, and (3) serve as a host for GNC software and hardware development and testing. The initial capabilities of the FFTB are based upon an integration of high fidelity hardware and software simulation, emulation, and test platforms developed or employed at GSFC in recent years, including a high-fidelity Global Positioning System (GPS) simulator which has been a fundamental component of the GNC Center's GPS Test Facility. The FFTB will be continuously evolving over the next several years from a tool with capabilities in GPS navigation hardware/software-in-the-loop analysis and closed loop GPS-based orbit control algorithm assessment. Eventually, it will include full capability to support all aspects of multi-sensor, absolute and relative state determination and control, in all (attitude and orbit) degrees of freedom, as well as information management for satellite clusters and constellations. A detailed description of the FFTB architecture is presented in the paper.

Burns, Rich; Bauer, Frank H. (Technical Monitor)

2002-01-01

372

Combined Global Navigation Satellite Systems in the Space Service Volume.  

National Technical Information Service (NTIS)

Besides providing position, velocity, and timing (PVT) for terrestrial users, the Global Positioning System (GPS) is also being used to provide PVT information for earth orbiting satellites. In 2006, F. H. Bauer, et. al., defined the Space Service Volume ...

D. A. Force J. J. Miller

2013-01-01

373

The Utility and Validity of Kinematic GPS Positioning for the Geosar Airborne Terrain Mapping Radar System  

NASA Technical Reports Server (NTRS)

GeoSAR is an airborne, interferometric Synthetic Aperture Radar (IFSAR) system for terrain mapping, currently under development by a consortium including NASA's Jet Propulsion Laboratory (JPL), Calgis, Inc., a California mapping sciences company, and the California Department of Conservation (CaIDOC), with funding provided by the U.S. Army Corps of Engineers Topographic Engineering Center (TEC) and the U.S. Defense Advanced Research Projects Agency (DARPA). IFSAR data processing requires high-accuracy platform position and attitude knowledge. On 9 GeoSAR, these are provided by one or two Honeywell Embedded GPS Inertial Navigation Units (EGI) and an Ashtech Z12 GPS receiver. The EGIs provide real-time high-accuracy attitude and moderate-accuracy position data, while the Ashtech data, post-processed differentially with data from a nearby ground station using Ashtech PNAV software, provide high-accuracy differential GPS positions. These data are optimally combined using a Kalman filter within the GeoSAR motion measurement software, and the resultant position and orientation information are used to process the dual frequency (X-band and P-band) radar data to generate high-accuracy, high -resolution terrain imagery and digital elevation models (DEMs). GeoSAR requirements specify sub-meter level planimetric and vertical accuracies for the resultant DEMS. To achieve this, platform positioning errors well below one meter are needed. The goal of GeoSAR is to obtain 25 cm or better 3-D positions from the GPS systems on board the aircraft. By imaging a set of known point target corner-cube reflectors, the GeoSAR system can be calibrated. This calibration process yields the true position of the aircraft with an uncertainty of 20- 50 cm. This process thus allows an independent assessment of the accuracy of our GPS-based positioning systems. We will present an overview of the GeoSAR motion measurement system, focusing on the use of GPS and the blending of position data from the various systems. We will present the results of our calibration studies that relate to the accuracy the GPS positioning. We will discuss the effects these positioning, errors have on the resultant DEM products and imagery.

Freedman, Adam; Hensley, Scott; Chapin, Elaine; Kroger, Peter; Hussain, Mushtaq; Allred, Bruce

1999-01-01

374

Balloon gravimetry using GPS and INS  

Microsoft Academic Search

Measurement of the horizontal components of gravity at altitude using balloon-borne instrumentation consisting of a Global Positioning System (GPS) receiver and a strapdown inertial navigation system (INS) is discussed. GPS data are to be used primarily to determine the total inertial acceleration of the balloon, while the INS accelerometers sense all nongravitational accelerations. A covariance analysis based on the Kalman

Christopher Jekeli; Hanscom AFB

1992-01-01

375

Balloon gravimetry using GPS and INS  

Microsoft Academic Search

The US Air Force has a project to measure the horizontal components of gravity at altitude using balloon-borne instrumentation consisting of a Global Positioning System (GPS) receiver and a strapdown inertial navigation system (INS). GPS data are to be used primarily to determine the total inertial acceleration of the balloon, while the INS accelerometers sense all nongravitational accelerations. A covariance

Christopher Jekeli

1992-01-01

376

The GPS Burst Detector W-Sensor  

Microsoft Academic Search

The NAVSTAR satellites have two missions: navigation and nuclear detonation detection. The main objective of this paper is to describe one of the key elements of the Nuclear Detonation Detection System (NDS), the Burst Detector W-Sensor (BDW) that was developed for the Air Force Space and Missle Systems Center, its mission on GPS Block IIR, and how it utilizes GPS

D. D. McCrady; P. Phipps

1994-01-01

377

Localizability Analysis for GPS/Galileo Receiver Autonomous Integrity Monitoring  

NASA Astrophysics Data System (ADS)

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 the receiver independent of any external reference systems, apart from the navigation signals themselves. Quality measures need to be used to evaluate the RAIM performance at different locations and under various navigation modes, such as GPS only and GPS/Galileo integration, etc. The quality measures should include both the reliability and localizability measures. Reliability is used to assess the capability of GPS/Galileo receivers to detect the outliers while localizability is used to determine the capability of GPS/Galileo receivers to correctly identify the detected outlier from the measurements processed.

Hewitson, Steve; Lee, Hung Kyu; Wang, Jinling

2004-05-01

378

GPS-Like Phasing Control of the Space Solar Power System Transmission Array  

NASA Technical Reports Server (NTRS)

The problem of phasing of the Space Solar Power System's transmission array has been addressed by developing a GPS-like radio navigation system. The goal of this system is to provide power transmission phasing control for each node of the array that causes the power signals to add constructively at the ground reception station. The phasing control system operates in a distributed manner, which makes it practical to implement. A leader node and two radio navigation beacons are used to control the power transmission phasing of multiple follower nodes. The necessary one-way communications to the follower nodes are implemented using the RF beacon signals. The phasing control system uses differential carrier phase relative navigation/timing techniques. A special feature of the system is an integer ambiguity resolution procedure that periodically resolves carrier phase cycle count ambiguities via encoding of pseudo-random number codes on the power transmission signals. The system is capable of achieving phasing accuracies on the order of 3 mm down to 0.4 mm depending on whether the radio navigation beacons operate in the L or C bands.

Psiaki, Mark L.

2003-01-01

379

Effects of Geodetic Uncertainties on a Damped Inertial Navigation System  

Microsoft Academic Search

Gravity uncertainties are an inexorable source of error in all inertial navigation systems and are particularly important in high-quality inertial navigation systems. In this paper the steady-state rms errors that are excited in a damped inertial navigation system are analytically determined for four gravity uncertainty models and two vehicle maneuver models. The statistical approach used in this paper is compared

Stanley Jordan

1973-01-01

380

Evaluation of an autonomous GPS-based system for intra-row weed control by assessing the tilled area  

Microsoft Academic Search

An automatic tillage system for inter- and intra-row weed control based on real-time kinematic GPS navigation and control\\u000a has been used to address the problem of mechanically removing weeds within rows of precision seeded crops. The system comprised\\u000a a side-shifting frame with an attached tine-rotor (cycloid hoe) with eight sigmoid-shaped, vertically directed tines. The\\u000a individual tines can be released for

M. Nørremark; H. W. Griepentrog; J. Nielsen; H. T. Søgaard

381

Relative Navigation of Formation-Flying Satellites  

NASA Technical Reports Server (NTRS)

This paper compares autonomous relative navigation performance for formations in eccentric, medium and high-altitude Earth orbits using Global Positioning System (GPS) Standard Positioning Service (SPS), crosslink, and celestial object measurements. For close formations, the relative navigation accuracy is highly dependent on the magnitude of the uncorrelated measurement errors. A relative navigation position accuracy of better than 10 centimeters root-mean-square (RMS) can be achieved for medium-altitude formations that can continuously track at least one GPS signal. A relative navigation position accuracy of better than 15 meters RMS can be achieved for high-altitude formations that have sparse tracking of the GPS signals. The addition of crosslink measurements can significantly improve relative navigation accuracy for formations that use sparse GPS tracking or celestial object measurements for absolute navigation.

Long, Anne; Kelbel, David; Lee, Taesul; Leung, Dominic; Carpenter, J. Russell; Grambling, Cheryl

2002-01-01

382

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

383

Synthesis of a Very Accurate Inertial Navigation System  

Microsoft Academic Search

A philosophy for the synthesis of a very accurate inertial navigation system is developed here. First, the requirements for a spherical earth navigator are determined, and the basis for a navigator error analysis is developed through the use of mathematical error models. Four types of redundant information are then considered in sequence: external speed information, redundant system gyro, external discrete

Arthur Gelb

1965-01-01

384

Automatic alignment and calibration of an inertial navigation system  

Microsoft Academic Search

In this paper we derive a simple six degree of freedom navigator, Earth-surface navigator, for terranean vehicle application, using low grade gyros. The calibration and alignment of the navigator are investigated when the system is at rest. Based on the observability of the error model when the system is at rest, a state transformation is presented. This transformation decouples the

Samer S. Saab; Kristjan T. Gunnarsson

1994-01-01

385

High performance strapdown inertial navigation system algorithms for space flight  

Microsoft Academic Search

To satisfy inertial navigation demands for space flight, high performance space-oriented strapdown inertial navigation system (SINS) algorithms are developed in the paper. The new algorithms are derived from a two-speed updating approach, which are far fit for the integration in digital computer than conventional methods and improve the robustness of space inertial navigation system (INS) in high dynamic environments. The

Liduan Wang; Ping Ye; Chuanrun Zhai; Yanhua Zhang

2008-01-01

386

Study on underwater navigation system based on geomagnetic match technique  

Microsoft Academic Search

Underwater vehicle navigation technique is one of the important issues to the development and application of the long-range underwater vehicle technology. In order to meet the concealment of underwater navigation, we present a kind of independent underwater navigation system based on geomagnetic match technique in this paper. Firstly, we introduce the composition of the system, the work principles and functions

Jianhu Zhao; Shengping Wang; Aixue Wang

2009-01-01

387

Tuning and Robustness Analysis for the Orion Absolute Navigation System  

NASA Technical Reports Server (NTRS)

The Orion Multi-Purpose Crew Vehicle (MPCV) is currently under development as NASA's next-generation spacecraft for exploration missions beyond Low Earth Orbit. The MPCV is set to perform an orbital test flight, termed Exploration Flight Test 1 (EFT-1), some time in late 2014. The navigation system for the Orion spacecraft is being designed in a Multi-Organizational Design Environment (MODE) team including contractor and NASA personnel. The system uses an Extended Kalman Filter to process measurements and determine the state. The design of the navigation system has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to show the efforts made to-date in tuning the filter for the EFT-1 mission and instilling appropriate robustness into the system to meet the requirements of manned space ight. Filter performance is affected by many factors: data rates, sensor measurement errors, tuning, and others. This paper focuses mainly on the error characterization and tuning portion. Traditional efforts at tuning a navigation filter have centered around the observation/measurement noise and Gaussian process noise of the Extended Kalman Filter. While the Orion MODE team must certainly address those factors, the team is also looking at residual edit thresholds and measurement underweighting as tuning tools. Tuning analysis is presented with open loop Monte-Carlo simulation results showing statistical errors bounded by the 3-sigma filter uncertainty covariance. The Orion filter design uses 24 Exponentially Correlated Random Variable (ECRV) parameters to estimate the accel/gyro misalignment and nonorthogonality. By design, the time constant and noise terms of these ECRV parameters were set to manufacturer specifications and not used as tuning parameters. They are included in the filter as a more analytically correct method of modeling uncertainties than ad-hoc tuning of the process noise. Tuning is explored for the powered-flight ascent phase, where measurements are scarce and unmodelled vehicle accelerations dominate. On orbit, there are important trade-off cases between process and measurement noise. On entry, there are considerations about trading performance accuracy for robustness. Process Noise is divided into powered flight and coasting ight and can be adjusted for each phase and mode of the Orion EFT-1 mission. Measurement noise is used for the integrated velocity measurements during pad alignment. It is also used for Global Positioning System (GPS) pseudorange and delta- range measurements during the rest of the flight. The robustness effort has been focused on maintaining filter convergence and performance in the presence of unmodeled error sources. These include unmodeled forces on the vehicle and uncorrected errors on the sensor measurements. Orion uses a single-frequency, non-keyed GPS receiver, so the effects due to signal distortion in Earth's ionosphere and troposphere are present in the raw measurements. Results are presented showing the efforts to compensate for these errors as well as characterize the residual effect for measurement noise tuning. Another robustness tool in use is tuning the residual edit thresholds. The trade-off between noise tuning and edit thresholds is explored in the context of robustness to errors in dynamics models and sensor measurements. Measurement underweighting is also presented as a method of additional robustness when processing highly accurate measurements in the presence of large filter uncertainties.

Holt, Greg N.; Zanetti, Renato; D'Souza, Christopher

2013-01-01

388

Propagation Effects at Radio Frequencies on Satellite Navigation Systems.  

National Technical Information Service (NTIS)

The report discusses the effects of the neutral and ionized atmosphere on radio frequency signals used in satellite navigation systems. Knowledge of the signal velocity along the transmission path is necessary to properly interpret the navigation measurem...

V. L. Pisacane M. M. Feen

1974-01-01

389

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

390

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

391

Robust GPS autonomous signal quality monitoring  

Microsoft Academic Search

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

Awele Nnaemeka Ndili

1998-01-01

392

International Time Comparison by a GPS (Global Positioning System) Timing Receiver.  

National Technical Information Service (NTIS)

Tokyo Astronomical Observatory (TAO) has started a regular reception of the Global Positioning System (GPS) timing signals for the purpose of a precise international time comparison. A test operation of the GPS receiver was performed from September 1982 t...

M. K. Fujimoto K. Fujiwara S. Aoki

1984-01-01

393

Near-Optimal Strategies for Sub-Decimeter Satellite Tracking with GPS (Global Positioning System).  

National Technical Information Service (NTIS)

Decimeter tracking of low Earth orbiters using differential Global Positioning System (GPS) techniques is discussed. A precisely known global network of GPS ground receivers and a receiver aboard the user satellite are needed, and all techniques simultane...

T. P. Yunck S. Wu J. Wu

1986-01-01

394

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

395

A GPS measurement system for precise satellite tracking and geodesy  

NASA Technical Reports Server (NTRS)

NASA is pursuing two key applications of differential positioning with the Global Positioning System (GPS): sub-decimeter tracking of earth satellites and few-centimeter determination of ground-fixed baselines. Key requirements of the two applications include the use of dual-frequency carrier phase data, multiple ground receivers to serve as reference points, simultaneous solution for use position and GPS orbits, and calibration of atmospheric delays using water vapor radiometers. Sub-decimeter tracking will be first demonstrated on the TOPEX oceanographic satellite to be launched in 1991. A GPS flight receiver together with at least six ground receivers will acquire delta range data from the GPS carriers for non-real-time analysis. Altitude accuracies of 5 to 10 cm are expected. For baseline measurements, efforts will be made to obtain precise differential pseudorange by resolving the cycle ambiguity in differential carrier phase. This could lead to accuracies of 2 or 3 cm over a few thousand kilometers. To achieve this, a high-performance receiver is being developed, along with improved calibration and data processing techniques. Demonstrations may begin in 1986.

Yunck, T. P.; Wu, S.-C.; Lichten, S. M.

1985-01-01

396

Integrated vision\\/inertial navigation system design using nonlinear filtering  

Microsoft Academic Search

Addresses the problem of navigation system design for autonomous aircraft landing. New nonlinear filter structures are introduced to estimate the position of an aircraft with respect to a possibly moving landing site, such as a naval vessel, based on measurements provided by airborne vision and inertial sensors. By exploring the geometry of the navigation problem, the navigation filter dynamics are

I. Kaminer; A. Pascoal; Wei Kang

1999-01-01

397

Estimating zenith tropospheric delays from BeiDou navigation satellite system observations.  

PubMed

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. PMID:23552104

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

2013-01-01

398

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

399

Simulation Of Satellite Trajectories And Navigation  

NASA Technical Reports Server (NTRS)

Orbit Analysis and Simulation Software, OASIS, is software system developed for covariance and simulation analyses of problems involving Earth satellites, especially Global Positioning System (GPS). Provides flexible, versatile, and efficient software tool for analysis of accuracy in Earth-satellite navigation and GPS-based geodetic studies.

Wu, Sien-Chong; Bertiger, William I.; Border, James S.; Lichten, Stephen M.; Sunseri, Richard F.; Williams, Bobby G.; Wolff, Peter J.; Wu, Jiun-Tsong

1989-01-01

400

Design and test of an integrated stabilization and navigation system for the Advanced Airborne Hyperspectral Imaging System (AAHIS)  

NASA Astrophysics Data System (ADS)

Science and Technology International (STI) has developed an integrated navigation and stabilization system for the Advanced Airborne Hyperspectral Imaging System (AAHIS). The sensor itself operates as a pushbroom imager, covering the wavelengths range from 435 nm to 830 nm with a ground resolution of 0.2 m2 per pixel and a spectral resolution of 182 channels. The system was designed for remote sensing applications utilizing small aircraft. A dGPS navigation system was developed which provides the user with a reliable computer interface for convenient mission planning and monitoring. All data acquisition functions are integrated and require little or no user input. The compact stabilization system consists of two mirrors on a rotation stage mounted in the optical path of the sensor. The navigation and stabilization CPU acquires position data from the differential GPS receiver, as well as attitude data from an inertial navigation system which measures linear and rotational motions. These movements are translated into real-time signals for the mirrors and the rotation stages, correcting for aircraft pitch, yaw and roll and off-track errors. The dGPS data are recorded and later merged with the hyperspectral data which can then be geo-registered and incorporated in a GIS map. The paper will present the approach that was taken to develop a compact stabilization system for hyperspectral imaging in less than 2 MY using off the shelf industrial components. It will quantify the benefit of the chosen approach over other forms of stabilization or no stabilization and discuss the technological and economic benefits for airborne remote sensing missions.

Even, Detlev M.; Johnson, Carl; Fala, Joe; Voelker, Mark A.; Mooradian, Gregory C.; Portigal, Frederick P.

1997-06-01

401

A Recommendation on SLR Ranging to Future Global Navigation Satellite Systems  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

402

GPS Animations  

NSDL National Science Digital Library

This site features Flash animations that illustrate how the Global Positioning System (GPS) works. The animations depict how GPS signals are derived, compare geostationary and polar orbits, and explain satellites, ground control, and user segments, which comprise the three main GPS components. These resources are suitable for use in lectures, labs, or other teaching activities.

2008-09-12

403

Kalman Filter Design for an Inertial Navigation System Aided by Non-Synchronous Navigation Satellite Constellations.  

National Technical Information Service (NTIS)

The report is a Kalman filter design study for the proposed Integrated Navigation Satellite/Inertial System (INI). Primary emphasis is placed upon determination of the 'best' filter state variable vector and investigation of various measurement rates usin...

G. T. Rhue R. R. Butler

1974-01-01

404

Libration Point Navigation Concepts Supporting the Vision for Space Exploration  

NASA Technical Reports Server (NTRS)

This work examines the autonomous navigation accuracy achievable for a lunar exploration trajectory from a translunar libration point lunar navigation relay satellite, augmented by signals from the Global Positioning System (GPS). We also provide a brief analysis comparing the libration point relay to lunar orbit relay architectures, and discuss some issues of GPS usage for cis-lunar trajectories.

Carpenter, J. Russell; Folta, David C.; Moreau, Michael C.; Quinn, David A.

2004-01-01

405

First results from an airborne GPS radio occultation system for atmospheric profiling  

NASA Astrophysics Data System (ADS)

Positioning System (GPS) radio occultation (RO) from low Earth-orbiting satellites has increased the quantity of high-vertical resolution atmospheric profiles, especially over oceans, and has significantly improved global weather forecasting. A new system, the Global Navigation Satellite Systems Instrument System for Multistatic and Occultation Sensing (GISMOS), has been developed for RO sounding from aircraft. GISMOS also provides high-vertical resolution profiles that are insensitive to clouds and precipitation, and in addition, provides greater control on the sampling location, useful for targeted regional studies. The feasibility of the system is demonstrated with a flight carried out during development of an Atlantic tropical storm. The data have been evaluated through a comparison with dropsonde data. The new airborne RO system will effectively increase by more than 50% the number of profiles available for studying the evolution of tropical storms during this campaign and could potentially be deployed on commercial aircraft in the future.

Haase, J. S.; Murphy, B. J.; Muradyan, P.; Nievinski, F. G.; Larson, K. M.; Garrison, J. L.; Wang, K.-N.

2014-03-01

406

Navigation systems for approach and landing of VTOL aircraft  

NASA Technical Reports Server (NTRS)

The formulation and implementation of navigation systems used for research investigations in the V/STOLAND avionics system are described. The navigation systems prove position and velocity in a cartestian reference frame aligned with the runway. They use filtering techniques to combine the raw position data from navaids (e.g., TACAN, MLS) with data from onboard inertial sensors. The filtering techniques which use both complementary and Kalman filters, are described. The software for the navigation systems is also described.

Schmidt, S. F.; Mohr, R. L.

1979-01-01

407

Tactile Wayfinder: Comparison of Tactile Waypoint Navigation with Commercial Pedestrian Navigation Systems  

Microsoft Academic Search

\\u000a In this paper we report on a field study comparing a commercial pedestrian navigation system to a tactile navigation system\\u000a called Tactile Wayfinder. Similar to previous approaches the Tactile Wayfinder uses a tactile torso display to present the directions of a route’s waypoints to the user. It advances those approaches by\\u000a conveying the location of the next two waypoints rather

Martin Pielot; Susanne Boll

2010-01-01

408

State Estimation of ALV Integrated Navigation System Based on BP Neural Network  

Microsoft Academic Search

In this paper, a data fusion method based on BP neural network and DR is proposed for ALV's navigation. Mathematical models have been established for data fusion. When GPS is valid, neural network is adopted, which is three layered network with 5 input\\/ 3 output neurons with a single hidden layer. When GPS is invalid, DR is introduced by using

Meiling Wang; Yongwei Fu

2008-01-01

409

IRIG Standard Format for Global Positioning System (GPS) Data for Post-Operation Interrange Exchange.  

National Technical Information Service (NTIS)

Document provides standard format for post-operation exchange of NAVSTAR/Global Positioning system (GPS) data between the ranges and is designed to produce an efficient and cost effective GPS data exchange format. This format is independent of the GPS rec...

1991-01-01

410

GPS Meteorology: Remote Sensing of Atmospheric Water Vapor Using the Global Positioning System  

Microsoft Academic Search

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

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

1992-01-01

411

Global Positioning System (GPS) and GPS-Acoustic Observations: Insight into Slip Along the Subduction Zones Around Japan  

NASA Astrophysics Data System (ADS)

The global positioning system (GPS) is one of the most powerful tools available for observation of Earth's surface deformation. In particular, coseismic, postseismic, slow transient, and interseismic deformation have all been observed globally by GPS over the past two decades, especially in subduction zones. Moreover, GPS-acoustic techniques have been developed for practical use in the past decade, allowing observation of offshore deformation immediately above slip regions. Here, we describe the application of GPS and GPS-acoustic observations to the detection of deformation due to plate boundary slip for interplate earthquakes as well as afterslip and slow slip events in subduction zones around Japan, where geodetic data coverage is particularly dense. The data demonstrate temporally variable strain accumulation in the source region of the 2011 Mw 9.0 Tohoku-oki earthquake, and observation of the huge slip of the Tohoku-oki earthquake near the trench using GPS-acoustic methods has considerably advanced our knowledge of stress release and accumulation in this subduction zone.

Nishimura, Takuya; Sato, Mariko; Sagiya, Takeshi

2014-05-01

412

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

413

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

USGS Publications Warehouse

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

Sanchez, Richard D.

2004-01-01

414

Field experience and assessment of GPS signal receiving and distribution system for synchronizing power system protection, control and monitoring  

Microsoft Academic Search

This paper describes the field experience and assessment of a GPS signal receiving and distribution system for synchronizing power system protection, control and monitoring. Application of GPS synchronization to protection, control and monitoring systems is becoming more popular in the field of power systems. However, the actual performance and reliability of GPS signal receipt within the substation environment has not

Daiju Itagaki; Kenichiro Ohashi; Itsuo Shuto; Hachidai Ito

2006-01-01

415

Kinematic Azimuth Alignment of INS using GPS Velocity Information  

Microsoft Academic Search

The combination of the Global Positioning System (GPS) and an Inertial Navigation System (INS) can deliver a system performance that is superior to either one in stand- alone mode, since each system compensates for the other's shortcomings. Due to large errors of the inertial sensors, error estimation and further compensation have to be performed using external information from GPS. The

A. O. Salycheva; M. E. Cannon

2004-01-01

416

Research of GPS integrity monitoring  

NASA Astrophysics Data System (ADS)

Integrity is one of the four basic parameters (accuracy, continuity and availability as the other three) which are used to assess the performance of satellite navigation systems. This paper introduces the basic concept of integrity and analyses the factors which affect the integrity of GPS. Focusing on the three main components of GPS and in terms of the object to which integrity monitoring aims, the paper puts forward a new classification of the technology. The paper classifies the technology into three categories, namely RAIM (Receiver Autonomous Integrity Monitoring), GIC (GPS Integrity Channel) and SAIM (Satellite Autonomous Integrity Monitoring) and studies several typical methods of integrity monitoring.

Yu, Xia-qiong; Dong, Xu-rong; Tang, Bin; Huang, Xiao-yu

2007-11-01

417

The REFSAT approach to low-cost GPS terminals  

NASA Technical Reports Server (NTRS)

A concept utilizing a geostationary reference satellite (REFSAT) that broadcasts navigation aiding signals to low cost civil user terminals which employ the constellation of 24 NAVSTAR Global Positioning System (GPS) satellites for position determination is described. The signal acquisition, tracking and position fixing properties of such low cost, dual channel, L-band, civil user receiver designed to receive both GPS navigation and REFSAT navigation aiding signals is presented. REFSAT reduces the cost of user equipment.

Sennott, J. W.; Choudhury, A. K.; Taylor, R. E.

1979-01-01

418

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

419

Performance evaluation of inertial navigation systems for surveying  

Microsoft Academic Search

Many modern surveying and mapping techniques (such as Mobile Mapping Systems - MMS) rely on Inertial Navigation Systems (INSs) to provide precise navigation data including position, velocity and attitude (PVA). With the increasing demand for improvements in accuracy of such surveying and mapping systems, there is an obvious necessity for the operators to understand the capabilities and characteristics of the

S. A. Hewitson; J. Wang; A. H. W. Kearsley

2003-01-01

420

Calibration procedures for laser gyro strapdown inertial navigation systems  

Microsoft Academic Search

A cost-effective simple rapid test procedure is described which permit precise calibrations of critical sensor error parameters in a laser gyro strapdown inertial navigation system on the basis of relatively inaccurate test instrumentation. The sensor errors are evaluated by monitoring the navigational performance of the strapdown system under normal dynamic operating conditions, and relating measured system performance anomalies to the

P. G. Savage

1977-01-01

421

The Navigation System of the JPL Robot  

Microsoft Academic Search

The control structure of the JPL research robot and the operations of the navigation subsys­ tem are discussed. The robot functions as a network of interacting concurrent processes dis­ tributed among several computers and coordinated by a central executive. The results of scene analysis are used to create a segmented terrain model in which surface regions are classified by traversibility.

Alan M. Thompson

1977-01-01

422

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

423

Prov Med GPS/GLONASS. Stoerning mot Satellitnavigering. Oeversiktlig Vaerdering (Test of Accuracy of GPS/GLONSS. Jamming of Satellite Navigation).  

National Technical Information Service (NTIS)

The objective of this report is to give an overview of some important results and topics produced within the scope of the FOA project 'Robust navigation'. The study is sponsored with the aim of enhancing our ability of assessing the technical advances on ...

S. Arnzen A. Alm J. Arnsby M. Davidson E. Marits

1998-01-01

424

33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false McClellan-Kerr Arkansas River navigation system: use, administration...207.275 McClellan-Kerr Arkansas River navigation system: use, administration...in the following waterways: The White River between Mississippi River and...

2011-07-01

425

33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false McClellan-Kerr Arkansas River navigation system: use, administration...207.275 McClellan-Kerr Arkansas River navigation system: use, administration...in the following waterways: The White River between Mississippi River and...

2012-07-01

426

Ubiquitous Positioning Technologies for Modern Intelligent Navigation Systems  

Microsoft Academic Search

Recently new location technologies have emerged that can be employed in modern advanced navigation systems. They can be employed to augment Global Navigation Satellite System (GNSS) positioning techniques and dead reckoning as they offer different levels of positioning accuracies and performance. An integration of other technologies is especially required in indoor and outdoor-to-indoor environments. The paper gives an overview of

Guenther Retscher; Allison Kealy

2006-01-01

427

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

2012-01-01

428

Enhancing Positioning Accuracy in Urban Terrain by Fusing Data from a GPS Receiver, Inertial Sensors, Stereo-Camera and Digital Maps for Pedestrian Navigation  

PubMed Central

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.

Przemyslaw, Baranski; Pawel, Strumillo

2012-01-01

429

A Micromechanical INS/GPS System for Small Satellites  

NASA Technical Reports Server (NTRS)

The cost and complexity of large satellite space missions continue to escalate. To reduce costs, more attention is being directed toward small lightweight satellites where future demand is expected to grow dramatically. Specifically, micromechanical inertial systems and microstrip global positioning system (GPS) antennas incorporating flip-chip bonding, application specific integrated circuits (ASIC) and MCM technologies will be required. Traditional microsatellite pointing systems do not employ active control. Many systems allow the satellite to point coarsely using gravity gradient, then attempt to maintain the image on the focal plane with fast-steering mirrors. Draper's approach is to actively control the line of sight pointing by utilizing on-board attitude determination with micromechanical inertial sensors and reaction wheel control actuators. Draper has developed commercial and tactical-grade micromechanical inertial sensors, The small size, low weight, and low cost of these gyroscopes and accelerometers enable systems previously impractical because of size and cost. Evolving micromechanical inertial sensors can be applied to closed-loop, active control of small satellites for micro-radian precision-pointing missions. An inertial reference feedback control loop can be used to determine attitude and line of sight jitter to provide error information to the controller for correction. At low frequencies, the error signal is provided by GPS. At higher frequencies, feedback is provided by the micromechanical gyros. This blending of sensors provides wide-band sensing from dc to operational frequencies. First order simulation has shown that the performance of existing micromechanical gyros, with integrated GPS, is feasible for a pointing mission of 10 micro-radians of jitter stability and approximately 1 milli-radian absolute error, for a satellite with 1 meter antenna separation. Improved performance micromechanical sensors currently under development will be suitable for a range of micro-nano-satellite applications.

Barbour, N.; Brand, T.; Haley, R.; Socha, M.; Stoll, J.; Ward, P.; Weinberg, M.

1995-01-01

430

A microcomputer-based low-cost Omega navigation system  

NASA Technical Reports Server (NTRS)

The application of a low cost, commercially available microcomputer as the navigation processor for a simplified OMEGA navigation system is an area of current research. The interface of a low cost front end OMEGA sensor is described and an example of the phase processing software and navigation routines is given. Emphasis is placed on the description of results obtained with the software version of the OMEGA burst filter known as the memory aided phase locked loop.

Lilley, R. W.; Salter, R. J., Jr.

1976-01-01

431

Gravity-model errors in mobile inertial-navigation systems  

Microsoft Academic Search

A high-accuracy inertial-navigation system (INS) is to be used to navigate a land-mobile vehicle travelling at about 30 knots, over time periods of 2-4 h or less. Important sources of navigation error are the errors in modeling the anomalous gravity forces acting on the vehicle. To obtain acceptable performance, the INS must be accurately compensated in real time for the

B. A. Kriegsman; K. B. Mahar

1986-01-01

432

An analysis of GDOP in global positioning system navigation  

NASA Technical Reports Server (NTRS)

The accuracy of user navigation fix based on the NAVSTAR global positioning system is described. The trace of this matrix serves as a convenient navigation performance index and the square root of the trace is called geometric dilution of precision (GDOP). Certain theoretical results concerning the general properties of the navigation performance are derived. An efficient algorithm for the computation of GDOP is given. Applications of the results are illustrated by numerical examples.

Fang, B. T.

1980-01-01

433

The Cyclone Global Navigation Satellite System: An 8-Satellite Constellation Mission  

NASA Astrophysics Data System (ADS)

Recently, NASA selected the Cyclone Global Navigation Satellite System (CYGNSS) mission for the Earth Venture Space System. The scientific goal of CYGNSS is to better understand the development of strong winds within the core of tropical cyclones. It will allow scientists to achieve this goal by inferring the surface winds through the use of reflected Global Position Satellite (GPS) signals off the ocean surface. Each of the eight CYGNSS satellites measures both direct and indirect GPS signals. These electromagnetic waves specularly reflect off of the ocean surface, allowing the roughness to be determined. This roughness is proportional to the surface wind speed. One of the important features of using GPS signals is that they are not attenuated by heavy rain fall, allowing the wind to be inferred throughout a tropical cyclone. The eight microsats will be launched by a single launch vehicle and will spread out across their orbit over about two weeks. After this, they will provide coverage of the wind speeds within 35 degrees of the equator with relatively rapid repeat times. This talk will present the scientific goals of CYGNSS, the characteristics of the eight microsats their orbit, and the status of the mission.

Ridley, A. J.; Ruf, C. S.; Rose, R.; Scherrer, J.

2012-12-01

434

Color and Texture Features for Landmarks Recognition on UAV Navigation  

Microsoft Academic Search

Image processing in real-time is a fundamental issue in many applications in computer vision such as remote sensing, tracking and autonomous navigation. Nowadays many unmanned aerial vehicles (UAVs) depend on Global Positioning System (GPS) and inertial systems for navigation and are controlled by a ground control station. Vision systems could improve the autonomous capacity of navigation of such vehicles. The

Ricardo Bonfim Rodrigues; Elcio Hideiti Shiguemori; Carlos Henrique; Roberto M. Pellegrino; P. Marechal Eduardo Gomes

2009-01-01

435

Navigating the Airways  

NASA Technical Reports Server (NTRS)

Through a licensing agreement with JPL, Hughes Aircraft Company is using the Jet Propulsion Laboratory's (JPL) software GIPSY-OASIS for implementation of the Federal Aviation Administration's Wide Area Augmentation System (WAAS). WAAS will provide precision navigation for commercial airliners in U.S. airspace. JPL's GIPSY-OASIS (GIPSY - GPS-Inferred Positioning System; OASIS - Orbit Analysis and Simulation Software) has been used world-wide to produce the most accurate Global Positioning System (GPS) ephemeredes (satellite position) solutions ever achieved for ground and space users, both in scientific and commercial applications.

1999-01-01

436

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

437

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

438

Clock performance as a critical parameter in navigation satellite systems  

NASA Technical Reports Server (NTRS)

The high performance of available oscillators has permitted the development of invaluable navigation and geodetic satellite systems. However, still higher performance oscillators would further improve the accuracy or flexibility of the systems.

Anderle, R. J.

1978-01-01

439

Precursor Systems Analyses of Automated Highway Systems. Carrier Phase GPS for AHS Vehicle Control. Resource Materials.  

National Technical Information Service (NTIS)

This report describs the results of a PSA contract awarded to SRI International to analyze applications of advanced Global Positioning System (GPS) measurement techniques to provide data for lateral and longitudinal control of AHS vehicles. The report inc...

R. C. Galijan

1996-01-01

440

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

441

Study and Realization of Multimedia Intelligent Tourism Navigation System  

Microsoft Academic Search

In this paper, we design a multimedia intelligent tourism navigation system and develop such a platform with the functions of virtual tourism, travel route planning, self-navigation and rescue. Multimedia interactive services facilitate visitors' self-service travel, and provide function of emergency process and rescue in tourism spot.

Gao Tian; Du Junping; Wang Su

2009-01-01

442

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

443

Strapdown relative inertial navigation system design for a lunar rover  

Microsoft Academic Search

To satisfy navigation demands for lunar rover operation in rough, unstructured terrain of lunar surface, a new strapdown relative inertial navigation system (SRINS) is proposed in the paper. Inertial measurements data are generated based on true trajectory of lunar rover and error models of inertial sensors (gyro and accelerometer), which are used to perform high-fidelity simulations to validate the performance

Liduan Wang; Xingqun Zhan; Yanhua Zhang; Hongliang Xu

2007-01-01

444

Field calibration for platform inertial navigation system based on RHKF  

Microsoft Academic Search

In this paper, a calibration method for platform inertial navigation system is proposed. By using this method, the calibration process can be completed without any turntables. For the inertial navigation platform which has full degrees of freedom in Yaw axis and ±60° degrees of freedom in the Roll and Pitch axis, a four-position field calibration method using receding horizon Kalman

Fan Mo; Zhihong Deng; Bo Wang; Mengyin Fu

2010-01-01

445

Regionalized Lunar South Pole Surface Navigation System Analysis  

NASA Technical Reports Server (NTRS)

Apollo missions utilized Earth-based assets for navigation because the landings took place at lunar locations in constant view from the Earth. The new exploration campaign to the lunar south pole region will have limited Earth visibility, but the extent to which a navigation system comprised solely of Earth-based tracking stations will provide adequate navigation solutions in this region is unknown. This report presents a dilution-of-precision (DoP)-based, stationary surface navigation analysis of the performance of multiple lunar satellite constellations, Earth-based deep space network assets, and combinations thereof. Results show that kinematic and integrated solutions cannot be provided by the Earth-based deep space network stations. Also, the stationary surface navigation system needs to be operated either as a two-way navigation system or as a one-way navigation system with local terrain information, while the position solution is integrated over a short duration of time with navigation signals being provided by a lunar satellite constellation.

Welch, Bryan W.

2008-01-01

446

Evaluation and Updating of Lorac Navigation System on Monterey Bay.  

National Technical Information Service (NTIS)

A LORAC system of navigation has been established in the Monterey Bay area and is intended for use in the field of ocean sciences research. It operates on a phase comparison principle and provides highly accurate navigational fixes without complex timing ...

A. F. Durkee

1969-01-01

447

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

448

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

449

Positional accuracy of the Wide Area Augmentation System in consumer-grade GPS units  

Microsoft Academic Search

Global Positioning System devices are increasingly being used for data collection in many fields. Consumer-grade GPS units without differential correction have a published horizontal positional accuracy of approximately 10–15m (average positional accuracy). An attractive option for differential correction for these GPS units is the Wide Area Augmentation System (WAAS). Most consumer-grade GPS units on the market are WAAS capable. According

Lisa L. Arnold; Paul A. Zandbergen

2011-01-01

450

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.  

Code of Federal Regulations, 2012 CFR

...position-fixing device. An electronic position-fixing device, a satellite navigational system such as the Global Positioning System (GPS) as required by § 164.41, if the vessel engages in towing seaward of navigable waters of the...

2012-07-01

451

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.  

Code of Federal Regulations, 2011 CFR

...position-fixing device. An electronic position-fixing device, a satellite navigational system such as the Global Positioning System (GPS) as required by § 164.41, if the vessel engages in towing seaward of navigable waters of the...

2011-07-01

452

Where should i turn: moving from individual to collaborative navigation strategies to inform the interaction design of future navigation systems  

Microsoft Academic Search

The design of in-vehicle navigation systems fails to take into account the social nature of driving and automobile navigation. In this paper, we consider navigation as a social activity among drivers and navigators to improve design of such systems. We explore the implications of moving from a map-centered, individually-focused design paradigm to one based upon collaborative human interaction during the

Jodi Forlizzi; William C. Barley; Thomas Seder

2010-01-01

453

The time keeping system for GPS block IIR  

NASA Technical Reports Server (NTRS)

The precision time keeping system (TKS) in the Global Positioning System (GPS), Block IIR satellites is designed to operate under severe natural and man made environmental conditions. The Block IIR TKS provides precise, autonomous time keeping for periods of up to seven months, without the intervention of the GPS Control Segment. The TKS is implemented using both linear and non-linear controls. The resulting TKS architecture uses a hybrid analog/digital phase locked loop (PLL). The paper provides details of the design and analysis of the TKS. The simulation techniques and the test bed activities used in performing the TKS design trade-offs are described. The effects of non-linear controls are analyzed using a TKS computer simulation of the PLL. The results from a hardware test bed are provided that verify desired TKS operation. The design criteria for the TKS computer simulation and the hardware test bed are indicated. The concepts for verification and testing of the TKS computer simulation and hardware test bed are presented.

Rawicz, H. C.; Epstein, M. A.; Rajan, J. A.

1993-01-01

454

Field Comparison of Driving Performance Using a Portable Navigation System  

NASA Astrophysics Data System (ADS)

Recent work has revealed that increasing numbers of drivers now receive driving instructions using a portable navigation system. A 22 (positionvoice) factorial experiment was executed to compare driving performance when using a portable navigation system (PNS). Thirty-two subjects were paid to participate in this field study, and a smart phone was adopted as the portable navigation device. The results indicated that drivers using the PNS under the conditions up position and with voice instruction performed better in terms of trip duration, mean speed, and the standard deviation of speed.

Lee, Wen-Chen; Ma, Mi-Chia; Cheng, Bor-Wen

455

GPS\\/INS integrated measurement system on Earth-circling spacecraft  

Microsoft Academic Search

This paper proposes GPS\\/INS integrated to implement the positioning and the attitude determination of the Earth-circling spacecraft. Observability analysis shows that the integration system, in which only GPS pseudo-range and delta pseudo-range are the observable, cannot assure favorable observability of the attitude error angles. The GPS carrier phase observable can be introduced to enhance the reliability and the precision in

Feng Wen-jiang; Yu Ping; Yang Shi-zhong

2001-01-01

456

12. LOCK, ELECTRICAL SYSTEM, LOCK, DAM, AND NAVIGATION LIGHTING UNITS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. LOCK, ELECTRICAL SYSTEM, LOCK, DAM, AND NAVIGATION LIGHTING UNITS (October 1935) - Mississippi River 9-Foot Channel Project, Lock & Dam No. 18, Upper Mississippi River, Gladstone, Henderson County, IL

457

76. LOCK, ELECTRICAL SYSTEM, LOCK, DAM AND NAVIGATION LIGHTING UNITS. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

76. LOCK, ELECTRICAL SYSTEM, LOCK, DAM AND NAVIGATION LIGHTING UNITS. February 1938 - Mississippi River 9-Foot Channel Project, Lock & Dam No. 17, Upper Mississippi River, New Boston, Mercer County, IL

458

Neural network correction of a vector gravitoinertial navigation system  

NASA Astrophysics Data System (ADS)

The concept and model of correction of a 3D inertial navigation system capable of estimating earth's gravitational field anomalies are suggested. The results of the computational experiment are presented.

Devyatisil'nyi, A. S.

2013-12-01

459

Differential GPS for air transport: Status  

NASA Technical Reports Server (NTRS)

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